WO2025118233A1

WO2025118233A1 - Multiple timing advance values for uplink dense deployments

Info

Publication number: WO2025118233A1
Application number: PCT/CN2023/137074
Authority: WO
Inventors: Shaozhen GUO; Mostafa KHOSHNEVISAN; Xiaoxia Zhang
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2023-12-07
Filing date: 2023-12-07
Publication date: 2025-06-12
Anticipated expiration: 2026-06-07

Abstract

Methods, systems, and devices for wireless communications are described. Techniques described herein support sounding reference signal (SRS) transmission via an indicated TA value or a special TA value, rules and conditions for determining which TA value to apply to which timing advance group (TAG), and mechanisms for receiving an initial TA value based on such SRS transmissions. A user equipment (UE) may apply a TA value of zero for an initial SRS transmissions, or may select a default TA value or an indicated TA value based on whether a timer for a TAG is running, based on a transmission configuration indicator (TCI) state corresponding to a TAG, or any combination thereof. The indication of the updated initial TA value (e.g., based on the SRS signaling) may be included in a RAR message or a MAC-CE message.

Description

MULTIPLE TIMING ADVANCE VALUES FOR UPLINK DENSE DEPLOYMENTS

FIELD OF TECHNOLOGY

The following relates to wireless communications, including multiple timing advance (TA) values for uplink dense deployments.

BACKGROUND

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal FDMA (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations, each supporting wireless communication for communication devices, which may be known as user equipment (UE) .

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support multiple timing advance (TA) values for uplink dense deployments. For example, techniques described herein support sounding reference signal (SRS) transmission via an indicated TA value or a special TA value, rules and conditions for determining which TA value or which timing advance group (TAG) or both for SRS transmission, and mechanisms for receiving an initial TA value based on such SRS transmissions, among other aspects. A user equipment (UE) may apply a first TA value (e.g., a value of zero) for an initial SRS transmissions, or may select a default TA value or an indicated TA value based on whether a timer for a TAG is running, based on a transmission configuration indicator (TCI) state corresponding to a TAG, or any combination thereof. The indication of the updated initial TA value (e.g., based on the SRS signaling) may be included in a message, such as an absolute TA command medium access control (MAC) control element (CE) or a MAC-CE message.

A method for wireless communications by a user equipment (UE) is described. The method may include receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier, applying, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG, and transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

A UE for wireless communications is described. The UE may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively operable to execute the code to cause the UE to receive control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier, apply, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG, and transmit, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

Another UE for wireless communications is described. The UE may include means for receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier, means for applying, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG, and means for transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to receive control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier, apply, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG, and transmit, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the first TA value includes a sum of a first delay value and the TA offset value, and the second TA value includes a sum of a second delay value and the TA offset value.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the first TA value includes a sum of a first delay value and the TA offset value and the second TA value includes a sum of a second delay value and a second TA offset value that may be equal to zero.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the control signaling includes a first index value corresponding to the first TAG, and a second index value corresponding to the second TAG and applying the second TA value including the sum of the second delay value and the second TA offset value that may be equal to zero to the second TAG may be based on the first index value being lower or higher than the second index value.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the control signaling includes a first indication of the first TAG and a second indication of a second TAG and applying the second TA value including the sum of the second delay value and the second TA offset value that may be equal to zero to the second TAG may be based on the second TAG corresponding to the first TAG or the second TAG.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for applying the second TA value including the sum of the second delay value and the second TA offset value that may be equal to zero to the second TAG may be based on a pathloss value, a pathloss offset, or an source sounding reference signal resource being associated with the first TAG.

A method for wireless communications by a UE is described. The method may include receiving control signaling indicating a first TAG and a second TAG for a component carrier, selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling, and transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

A UE for wireless communications is described. The UE may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively operable to execute the code to cause the UE to receive control signaling indicating a first TAG and a second TAG for a component carrier, select a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling, and transmit a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

Another UE for wireless communications is described. The UE may include means for receiving control signaling indicating a first TAG and a second TAG for a component carrier, means for selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling, and means for transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to receive control signaling indicating a first TAG and a second TAG for a component carrier, select a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling, and transmit a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, selecting the first TA value may include operations, features, means, or instructions for setting the first TA value equal to zero, where the first TAG may be selected and where transmitting the first set of one or more sounding reference signals according to the first TA value may be based on a downlink reference timing corresponding to the first TAG.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving second control signaling including an indication of the first TA value corresponding to the first TAG, where the first TAG corresponds to the first set of one or more sounding reference signals for beam management and initiating, based on receiving the second control signaling, a time alignment timer corresponding to the first TAG, where selecting the first TA value may be based on initiating the time alignment timer and a relationship between the set of sounding reference signal resources and the first TAG.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, selecting the first TA value may include operations, features, means, or instructions for selecting the first TA value equal to a default value may be based on a determination that a time alignment timer corresponding to the first TAG may be not running.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the default value corresponds to a TA value of the second TAG.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the default value may be equal to zero.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for selecting the one of the first TAG or the second TAG may be based on an order of configuration of the first TAG and the second TAG, an index value of the first TAG and an index value of the second TAG, an indication in the control signaling of a relationship between a set of sounding reference signals and the first TAG or the second TAG, or any combination thereof.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a random access response message indicating the second TAG, where selecting the one of the first TAG or the second TAG may be based on the random access response message indicating the second TAG.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving second control signaling activating or indicating a first transmission configuration indicator state corresponding with the first TAG, where selecting the first TAG may be based on receiving the second control signaling.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a radio resource control message indicating that the UE may be to set the first TA value equal to zero, or indicating that the UE may be to monitor for a control message indicating the first TA value, and where selecting the first TA value may be based on receiving the radio resource control message.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, based on transmitting the first set of one or more sounding reference signals, second control signaling indicating a second TA value corresponding to the first TAG, where the first TAG corresponds to the first set of one or more sounding reference signals for beam management and transmitting a second set of one or more sounding reference signals for beam management via the set of sounding reference signal resources of the component carrier according to the second TA value and the first TAG.

A method for wireless communications by a UE is described. The method may include transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value, receiving, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG, applying the second TA value to the first TAG, and transmitting uplink signaling according to the second TA value and the first TAG.

A UE for wireless communications is described. The UE may include one or more memories storing processor executable code, and one or more processors coupled with the one or more memories. The one or more processors may individually or collectively operable to execute the code to cause the UE to transmit a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value, receive, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG, apply the second TA value to the first TAG, and transmit uplink signaling according to the second TA value and the first TAG.

Another UE for wireless communications is described. The UE may include means for transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value, means for receiving, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG, means for applying the second TA value to the first TAG, and means for transmitting uplink signaling according to the second TA value and the first TAG.

A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by one or more processors to transmit a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value, receive, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG, apply the second TA value to the first TAG, and transmit uplink signaling according to the second TA value and the first TAG.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the control message includes a MAC_CE including a TA command indicating the second TA value.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the MAC-CE includes a field indicating the first TAG.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the control message includes a MAC-CE including a TA command indicating an offset value from a third TA value associated with a second TAG and the second TA value may be based on the offset value.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the second TAG may be a different TAG from the first TAG indicated in the MAC-CE, the first TAG indicated in the MAC-CE corresponding to the first TAG associated with the one or more sounding reference signal resources for beam management.

Some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving a random access response message indicating a TA value for a second TAG, where the second TAG may be a different TAG from the first TAG indicated in the MAC-CE, the first TAG being different than the second TAG indicated by the random access response message.

In some examples of the method, user equipment (UEs) , and non-transitory computer-readable medium described herein, the second TAG may be a different TAG from the first TAG indicated in MAC-CE, the MAC-CE being an earliest MAC-CE indicating the first TAG when a time alignment timer corresponding to the first TAG may be not running.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a wireless communications system that supports multiple timing (TA) advance values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 2 shows an example of a wireless communications system that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 3 shows an example of a timeline that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 4 shows an example of a timeline that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 5 shows an example of a timeline that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 6 shows an example of a timeline that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 7 shows an example of a timeline that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 8 shows an example of a process flow that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 9 shows an example of a process flow that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 10 shows an example of a process flow that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIGs. 11 and 12 show block diagrams of devices that support multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 13 shows a block diagram of a communications manager that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIG. 14 shows a diagram of a system including a device that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

FIGs. 15 through 17 show flowcharts illustrating methods that support multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure.

DETAILED DESCRIPTION

Some wireless communications systems may support dense uplink deployment scenarios where one or more uplink receive points are configured within the network and associated with a network entity. To improve uplink capacity and coverage, a dense uplink deployment may provide asymmetric downlink/uplink communications. Uplink signals from a user equipment (UE) may be received at an uplink receive point. Downlink signals may be transmitted from a network entity to the UE. The uplink receive points may be connected to the network entity via a backhaul connection. The uplink receive points may provide the uplink communications from the UE to the network entity via the backhaul network. The dense uplink deployment may reduce uplink pathloss (PL) , which may be helpful when the uplink coverage area is a bottleneck to throughput, among other conditions.

The UE may communicate uplink signaling that may be offset in time from an expected timing at one or more receiving devices (e.g., the uplink-only device and the network entity) . To address such timing misalignment, the network may configure the UE with a timing advance (TA) value, which may be or include a timing offset for uplink transmission that mitigate propagation delay. TA values may be applied to different TA groups (TAGs) . In some examples, the network may additionally configure the UE with a TA offset value to address uplink-downlink switching performed by the network entity. However, the uplink-only devices may not have any need for uplink-downlink switching, and such a TA offset may be redundant. Further, the UE may be configured with a single TA value, and multiple TAGs (e.g., one for communications with the network entity, and one for communications via the uplink-only device) .

According to techniques described herein, the UE may apply a single TA offset value to both TAGs, or may apply a TA offset value (e.g., of some value) to a first TAG (e.g., corresponding to the network entity) and may apply a TA offset value (e.g., of 0) to the second TAG (e.g., corresponding to the uplink-only device) . The UE may determine to which TAG to apply the TA offset value of 0 based on one or more rules or conditions (e.g., a TAG index value, RRC parameter associated with the TAG, etc. ) . In some examples, a first TAG and a second TAG may be determined based on the RRC parameter name associated with each TAG. For example, a first TAG may be associated with a first TAG identifier and the second TAG may be associated with a second TAG identifier, and the lower or higher value of the TAG identifier (e.g., as identified in an RRC parameter name) may define which TAG is the first TAG and which is the second TAG (e.g., to which TAG to apply the TA offset value) .

The UE may generally rely on a downlink receive beam for performing random access channel (RACH) signaling (e.g., for transmitting a physical random access channel (PRACH) message via a transmission beam corresponding to the downlink receive beam) . However, the uplink-only device may not be associated with any downlink receive beam. In such examples, the UE may transmit sounding reference signals (SRSs) that can be utilized by various uplink-only device to identify a preferred uplink-only device. The SRSs may further be utilized for calculating and determining a TA value for subsequent communications. However, the UE may not have access to information regarding an initial TA value for the SRS transmission, and may not be able to determine to which TAG to apply such a TA value.

Techniques described herein support SRS transmission via an indicated TA value or a special TA value, rules and conditions for determining which TA value or which TAG or both for SRS transmission, and mechanisms for receiving an initial TA value based on such SRS transmissions. For example, the UE may apply a TA value (e.g., of zero) for an initial SRS transmissions, or may select a default TA value or an indicated TA value based on whether a timer for a TAG is running, based on a TCI state corresponding to a TAG, or any combination thereof. The indication of the updated initial TA value (e.g., based on the SRS signaling) may be included in an absolute TA command MAC CE or a MAC-CE message, and may explicitly indicate the TA value, or may indicate an offset to a previous TA value, which the UE may interpret according to a current TAG or a previous TAG, a timer associated with one of the TAGs, or other rules and conditions.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to wireless communications systems, timelines, and process flows. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to multiple timing advance (TA) values for uplink dense deployments.

FIG. 1 shows an example of a wireless communications system 100 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The wireless communications system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating in accordance with other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

The network entities 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may include devices in different forms or having different capabilities. In various examples, a network entity 105 may be referred to as a network element, a mobility element, a radio access network (RAN) node, or network equipment, among other nomenclature. In some examples, network entities 105 and UEs 115 may wirelessly communicate via one or more communication links 125 (e.g., a radio frequency (RF) access link) . For example, a network entity 105 may support a coverage area 110 (e.g., a geographic coverage area) over which the UEs 115 and the network entity 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a network entity 105 and a UE 115 may support the communication of signals according to one or more radio access technologies (RATs) .

The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be capable of supporting communications with various types of devices, such as other UEs 115 or network entities 105, as shown in FIG. 1.

As described herein, a node of the wireless communications system 100, which may be referred to as a network node, or a wireless node, may be a network entity 105 (e.g., any network entity described herein) , a UE 115 (e.g., any UE described herein) , a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, a node may be a UE 115. As another example, a node may be a network entity 105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a UE 115. In another aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a network entity 105. In yet other aspects of this example, the first, second, and third nodes may be different relative to these examples. Similarly, reference to a UE 115, network entity 105, apparatus, device, computing system, or the like may include disclosure of the UE 115, network entity 105, apparatus, device, computing system, or the like being a node. For example, disclosure that a UE 115 is configured to receive information from a network entity 105 also discloses that a first node is configured to receive information from a second node.

In some examples, network entities 105 may communicate with the core network 130, or with one another, or both. For example, network entities 105 may communicate with the core network 130 via one or more backhaul communication links 120 (e.g., in accordance with an S1, N2, N3, or other interface protocol) . In some examples, network entities 105 may communicate with one another via a backhaul communication link 120 (e.g., in accordance with an X2, Xn, or other interface protocol) either directly (e.g., directly between network entities 105) or indirectly (e.g., via a core network 130) . In some examples, network entities 105 may communicate with one another via a midhaul communication link 162 (e.g., in accordance with a midhaul interface protocol) or a fronthaul communication link 168 (e.g., in accordance with a fronthaul interface protocol) , or any combination thereof. The backhaul communication links 120, midhaul communication links 162, or fronthaul communication links 168 may be or include one or more wired links (e.g., an electrical link, an optical fiber link) , one or more wireless links (e.g., a radio link, a wireless optical link) , among other examples or various combinations thereof. A UE 115 may communicate with the core network 130 via a communication link 155.

One or more of the network entities 105 described herein may include or may be referred to as a base station 140 (e.g., a base transceiver station, a radio base station, an NR base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB) , a 5G NB, a next-generation eNB (ng-eNB) , a Home NodeB, a Home eNodeB, or other suitable terminology) . In some examples, a network entity 105 (e.g., a base station 140) may be implemented in an aggregated (e.g., monolithic, standalone) base station architecture, which may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as a base station 140) .

In some examples, a network entity 105 may be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) , which may be configured to utilize a protocol stack that is physically or logically distributed among two or more network entities 105, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance) , or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN) ) . For example, a network entity 105 may include one or more of a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN Intelligent Controller (RIC) 175 (e.g., a Near-Real Time RIC (Near-RT RIC) , a Non-Real Time RIC (Non-RT RIC) ) , a Service Management and Orchestration (SMO) 180 system, or any combination thereof. An RU 170 may also be referred to as a radio head, a smart radio head, a remote radio head (RRH) , a remote radio unit (RRU) , or a transmission reception point (TRP) . One or more components of the network entities 105 in a disaggregated RAN architecture may be co-located, or one or more components of the network entities 105 may be located in distributed locations (e.g., separate physical locations) . In some examples, one or more network entities 105 of a disaggregated RAN architecture may be implemented as virtual units (e.g., a virtual CU (VCU) , a virtual DU (VDU) , a virtual RU (VRU) ) .

The split of functionality between a CU 160, a DU 165, and an RU 170 is flexible and may support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combinations thereof) are performed at a CU 160, a DU 165, or an RU 170. For example, a functional split of a protocol stack may be employed between a CU 160 and a DU 165 such that the CU 160 may support one or more layers of the protocol stack and the DU 165 may support one or more different layers of the protocol stack. In some examples, the CU 160 may host upper protocol layer (e.g., layer 3 (L3) , layer 2 (L2) ) functionality and signaling (e.g., Radio Resource Control (RRC) , service data adaption protocol (SDAP) , Packet Data Convergence Protocol (PDCP) ) . The CU 160 may be connected to one or more DUs 165 or RUs 170, and the one or more DUs 165 or RUs 170 may host lower protocol layers, such as layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160. Additionally, or alternatively, a functional split of the protocol stack may be employed between a DU 165 and an RU 170 such that the DU 165 may support one or more layers of the protocol stack and the RU 170 may support one or more different layers of the protocol stack. The DU 165 may support one or multiple different cells (e.g., via one or more RUs 170) . In some cases, a functional split between a CU 160 and a DU 165, or between a DU 165 and an RU 170 may be within a protocol layer (e.g., some functions for a protocol layer may be performed by one of a CU 160, a DU 165, or an RU 170, while other functions of the protocol layer are performed by a different one of the CU 160, the DU 165, or the RU 170) . A CU 160 may be functionally split further into CU control plane (CU-CP) and CU user plane (CU-UP) functions. A CU 160 may be connected to one or more DUs 165 via a midhaul communication link 162 (e.g., F1, F1-c, F1-u) , and a DU 165 may be connected to one or more RUs 170 via a fronthaul communication link 168 (e.g., open fronthaul (FH) interface) . In some examples, a midhaul communication link 162 or a fronthaul communication link 168 may be implemented in accordance with an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 105 that are in communication via such communication links.

In wireless communications systems (e.g., wireless communications system 100) , infrastructure and spectral resources for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, providing an IAB network architecture (e.g., to a core network 130) . In some cases, in an IAB network, one or more network entities 105 (e.g., IAB nodes 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as a donor entity or an IAB donor. One or more DUs 165 or one or more RUs 170 may be partially controlled by one or more CUs 160 associated with a donor network entity 105 (e.g., a donor base station 140) . The one or more donor network entities 105 (e.g., IAB donors) may be in communication with one or more additional network entities 105 (e.g., IAB nodes 104) via supported access and backhaul links (e.g., backhaul communication links 120) . IAB nodes 104 may include an IAB mobile termination (IAB-MT) controlled (e.g., scheduled) by DUs 165 of a coupled IAB donor. An IAB-MT may include an independent set of antennas for relay of communications with UEs 115, or may share the same antennas (e.g., of an RU 170) of an IAB node 104 used for access via the DU 165 of the IAB node 104 (e.g., referred to as virtual IAB-MT (vIAB-MT) ) . In some examples, the IAB nodes 104 may include DUs 165 that support communication links with additional entities (e.g., IAB nodes 104, UEs 115) within the relay chain or configuration of the access network (e.g., downstream) . In such cases, one or more components of the disaggregated RAN architecture (e.g., one or more IAB nodes 104 or components of IAB nodes 104) may be configured to operate according to the techniques described herein.

For instance, an access network (AN) or RAN may include communications between access nodes (e.g., an IAB donor) , IAB nodes 104, and one or more UEs 115. The IAB donor may facilitate connection between the core network 130 and the AN (e.g., via a wired or wireless connection to the core network 130) . That is, an IAB donor may refer to a RAN node with a wired or wireless connection to core network 130. The IAB donor may include a CU 160 and at least one DU 165 (e.g., and RU 170) , in which case the CU 160 may communicate with the core network 130 via an interface (e.g., a backhaul link) . IAB donor and IAB nodes 104 may communicate via an F1 interface according to a protocol that defines signaling messages (e.g., an F1 AP protocol) . Additionally, or alternatively, the CU 160 may communicate with the core network via an interface, which may be an example of a portion of backhaul link, and may communicate with other CUs 160 (e.g., a CU 160 associated with an alternative IAB donor) via an Xn-C interface, which may be an example of a portion of a backhaul link.

An IAB node 104 may refer to a RAN node that provides IAB functionality (e.g., access for UEs 115, wireless self-backhauling capabilities) . A DU 165 may act as a distributed scheduling node towards child nodes associated with the IAB node 104, and the IAB-MT may act as a scheduled node towards parent nodes associated with the IAB node 104. That is, an IAB donor may be referred to as a parent node in communication with one or more child nodes (e.g., an IAB donor may relay transmissions for UEs through one or more other IAB nodes 104) . Additionally, or alternatively, an IAB node 104 may also be referred to as a parent node or a child node to other IAB nodes 104, depending on the relay chain or configuration of the AN. Therefore, the IAB-MT entity of IAB nodes 104 may provide a Uu interface for a child IAB node 104 to receive signaling from a parent IAB node 104, and the DU interface (e.g., DUs 165) may provide a Uu interface for a parent IAB node 104 to signal to a child IAB node 104 or UE 115.

For example, IAB node 104 may be referred to as a parent node that supports communications for a child IAB node, or referred to as a child IAB node associated with an IAB donor, or both. The IAB donor may include a CU 160 with a wired or wireless connection (e.g., a backhaul communication link 120) to the core network 130 and may act as parent node to IAB nodes 104. For example, the DU 165 of IAB donor may relay transmissions to UEs 115 through IAB nodes 104, or may directly signal transmissions to a UE 115, or both. The CU 160 of IAB donor may signal communication link establishment via an F1 interface to IAB nodes 104, and the IAB nodes 104 may schedule transmissions (e.g., transmissions to the UEs 115 relayed from the IAB donor) through the DUs 165. That is, data may be relayed to and from IAB nodes 104 via signaling via an NR Uu interface to MT of the IAB node 104. Communications with IAB node 104 may be scheduled by a DU 165 of IAB donor and communications with IAB node 104 may be scheduled by DU 165 of IAB node 104.

In the case of the techniques described herein applied in the context of a disaggregated RAN architecture, one or more components of the disaggregated RAN architecture may be configured to support multiple TA values for uplink dense deployments as described herein. For example, some operations described as being performed by a UE 115 or a network entity 105 (e.g., a base station 140) may additionally, or alternatively, be performed by one or more components of the disaggregated RAN architecture (e.g., IAB nodes 104, DUs 165, CUs 160, RUs 170, RIC 175, SMO 180) .

A UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the network entities 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

The UEs 115 and the network entities 105 may wirelessly communicate with one another via one or more communication links 125 (e.g., an access link) using resources associated with one or more carriers. The term “carrier” may refer to a set of RF spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a RF spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR) . Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers. Communication between a network entity 105 and other devices may refer to communication between the devices and any portion (e.g., entity, sub-entity) of a network entity 105. For example, the terms “transmitting, ” “receiving, ” or “communicating, ” when referring to a network entity 105, may refer to any portion of a network entity 105 (e.g., a base station 140, a CU 160, a DU 165, a RU 170) of a RAN communicating with another device (e.g., directly or via one or more other network entities 105) .

In some examples, such as in a carrier aggregation configuration, a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute RF channel number (EARFCN) ) and may be identified according to a channel raster for discovery by the UEs 115. A carrier may be operated in a standalone mode, in which case initial acquisition and connection may be conducted by the UEs 115 via the carrier, or the carrier may be operated in a non-standalone mode, in which case a connection is anchored using a different carrier (e.g., of the same or a different radio access technology) .

The communication links 125 shown in the wireless communications system 100 may include downlink transmissions (e.g., forward link transmissions) from a network entity 105 to a UE 115, uplink transmissions (e.g., return link transmissions) from a UE 115 to a network entity 105, or both, among other configurations of transmissions. Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode) .

A carrier may be associated with a particular bandwidth of the RF spectrum and, in some examples, the carrier bandwidth may be referred to as a “system bandwidth” of the carrier or the wireless communications system 100. For example, the carrier bandwidth may be one of a set of bandwidths for carriers of a particular radio access technology (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz) ) . Devices of the wireless communications system 100 (e.g., the network entities 105, the UEs 115, or both) may have hardware configurations that support communications using a particular carrier bandwidth or may be configurable to support communications using one of a set of carrier bandwidths. In some examples, the wireless communications system 100 may include network entities 105 or UEs 115 that support concurrent communications using carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured for operating using portions (e.g., a sub-band, a BWP) or all of a carrier bandwidth.

Signal waveforms transmitted via a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) . In a system employing MCM techniques, a resource element may refer to resources of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The quantity of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) , such that a relatively higher quantity of resource elements (e.g., in a transmission duration) and a relatively higher order of a modulation scheme may correspond to a relatively higher rate of communication. A wireless communications resource may refer to a combination of an RF spectrum resource, a time resource, and a spatial resource (e.g., a spatial layer, a beam) , and the use of multiple spatial resources may increase the data rate or data integrity for communications with a UE 115.

One or more numerologies for a carrier may be supported, and a numerology may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs having the same or different numerologies. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time and communications for the UE 115 may be restricted to one or more active BWPs.

The time intervals for the network entities 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T_s=1/ (Δf_max·N_f) seconds, for which Δf_max may represent a supported subcarrier spacing, and N_f may represent a supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) . Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .

Each frame may include multiple consecutively-numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a quantity of slots. Alternatively, each frame may include a variable quantity of slots, and the quantity of slots may depend on subcarrier spacing. Each slot may include a quantity of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . In some wireless communications systems 100, a slot may further be divided into multiple mini-slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., N_f) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) . In some examples, the TTI duration (e.g., a quantity of symbol periods in a TTI) may be variable. Additionally, or alternatively, the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) ) .

Physical channels may be multiplexed for communication using a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed for signaling via a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET) ) for a physical control channel may be defined by a set of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115. For example, one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to an amount of control channel resources (e.g., control channel elements (CCEs) ) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets for sending control information to a specific UE 115.

A network entity 105 may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a network entity 105 (e.g., using a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) , or others) . In some examples, a cell also may refer to a coverage area 110 or a portion of a coverage area 110 (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the network entity 105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with coverage areas 110, among other examples.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered network entity 105 (e.g., a lower-powered base station 140) , as compared with a macro cell, and a small cell may operate using the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs 115 with service subscriptions with the network provider or may provide restricted access to the UEs 115 having an association with the small cell (e.g., the UEs 115 in a closed subscriber group (CSG) , the UEs 115 associated with users in a home or office) . A network entity 105 may support one or multiple cells and may also support communications via the one or more cells using one or multiple component carriers.

In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) ) that may provide access for different types of devices.

In some examples, a network entity 105 (e.g., a base station 140, an RU 170) may be movable and therefore provide communication coverage for a moving coverage area 110. In some examples, different coverage areas 110 associated with different technologies may overlap, but the different coverage areas 110 may be supported by the same network entity 105. In some other examples, the overlapping coverage areas 110 associated with different technologies may be supported by different network entities 105. The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the network entities 105 provide coverage for various coverage areas 110 using the same or different radio access technologies.

The wireless communications system 100 may support synchronous or asynchronous operation. For synchronous operation, network entities 105 (e.g., base stations 140) may have similar frame timings, and transmissions from different network entities 105 may be approximately aligned in time. For asynchronous operation, network entities 105 may have different frame timings, and transmissions from different network entities 105 may, in some examples, not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

Some UEs 115, such as MTC or IoT devices, may be low cost or low complexity devices and may provide for automated communication between machines (e.g., via Machine-to-Machine (M2M) communication) . M2M communication or MTC may refer to data communication technologies that allow devices to communicate with one another or a network entity 105 (e.g., a base station 140) without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application program that uses the information or presents the information to humans interacting with the application program. Some UEs 115 may be designed to collect information or enable automated behavior of machines or other devices. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception concurrently) . In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs 115 include entering a power saving deep sleep mode when not engaging in active communications, operating using a limited bandwidth (e.g., according to narrowband communications) , or a combination of these techniques. For example, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs) ) within a carrier, within a guard-band of a carrier, or outside of a carrier.

The wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) . The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions. Ultra-reliable communications may include private communication or group communication and may be supported by one or more services such as push-to-talk, video, or data. Support for ultra-reliable, low-latency functions may include prioritization of services, and such services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, and ultra-reliable low-latency may be used interchangeably herein.

In some examples, a UE 115 may be configured to support communicating directly with other UEs 115 via a device-to-device (D2D) communication link 135 (e.g., in accordance with a peer-to-peer (P2P) , D2D, or sidelink protocol) . In some examples, one or more UEs 115 of a group that are performing D2D communications may be within the coverage area 110 of a network entity 105 (e.g., a base station 140, an RU 170) , which may support aspects of such D2D communications being configured by (e.g., scheduled by) the network entity 105. In some examples, one or more UEs 115 of such a group may be outside the coverage area 110 of a network entity 105 or may be otherwise unable to or not configured to receive transmissions from a network entity 105. In some examples, groups of the UEs 115 communicating via D2D communications may support a one-to-many (1: M) system in which each UE 115 transmits to each of the other UEs 115 in the group. In some examples, a network entity 105 may facilitate the scheduling of resources for D2D communications. In some other examples, D2D communications may be carried out between the UEs 115 without an involvement of a network entity 105.

In some systems, a D2D communication link 135 may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115) . In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., network entities 105, base stations 140, RUs 170) using vehicle-to-network (V2N) communications, or with both.

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the network entities 105 (e.g., base stations 140) associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to IP services 150 for one or more network operators. The IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.

The wireless communications system 100 may operate using one or more frequency bands, which may be in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) . Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. UHF waves may be blocked or redirected by buildings and environmental features, which may be referred to as clusters, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. Communications using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to communications using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

The wireless communications system 100 may also operate using a super high frequency (SHF) region, which may be in the range of 3 GHz to 30 GHz, also known as the centimeter band, or using an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, the wireless communications system 100 may support millimeter wave (mmW) communications between the UEs 115 and the network entities 105 (e.g., base stations 140, RUs 170) , and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, such techniques may facilitate using antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

The wireless communications system 100 may utilize both licensed and unlicensed RF spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology using an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. While operating using unlicensed RF spectrum bands, devices such as the network entities 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations using unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating using a licensed band (e.g., LAA) . Operations using unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

A network entity 105 (e.g., a base station 140, an RU 170) or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a network entity 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a network entity 105 may be located at diverse geographic locations. A network entity 105 may include an antenna array with a set of rows and columns of antenna ports that the network entity 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may include one or more antenna arrays that may support various MIMO or beamforming operations. Additionally, or alternatively, an antenna panel may support RF beamforming for a signal transmitted via an antenna port.

The network entities 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords) . Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) , for which multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) , for which multiple spatial layers are transmitted to multiple devices.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a network entity 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating along particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

A network entity 105 or a UE 115 may use beam sweeping techniques as part of beamforming operations. For example, a network entity 105 (e.g., a base station 140, an RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a network entity 105 multiple times along different directions. For example, the network entity 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions along different beam directions may be used to identify (e.g., by a transmitting device, such as a network entity 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the network entity 105.

Some signals, such as data signals associated with a particular receiving device, may be transmitted by transmitting device (e.g., a transmitting network entity 105, a transmitting UE 115) along a single beam direction (e.g., a direction associated with the receiving device, such as a receiving network entity 105 or a receiving UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted along one or more beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the network entity 105 along different directions and may report to the network entity 105 an indication of the signal that the UE 115 received with a highest signal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a network entity 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or beamforming to generate a combined beam for transmission (e.g., from a network entity 105 to a UE 115) . The UE 115 may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured set of beams across a system bandwidth or one or more sub-bands. The network entity 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS) , a channel state information reference signal (CSI-RS) ) , which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook) . Although these techniques are described with reference to signals transmitted along one or more directions by a network entity 105 (e.g., a base station 140, an RU 170) , a UE 115 may employ similar techniques for transmitting signals multiple times along different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal along a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115) may perform reception operations in accordance with multiple receive configurations (e.g., directional listening) when receiving various signals from a transmitting device (e.g., a network entity 105) , such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may perform reception in accordance with multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal) . The single receive configuration may be aligned along a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR) , or otherwise acceptable signal quality based on listening according to multiple beam directions) .

The wireless communications system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, communications at the bearer or PDCP layer may be IP-based. An RLC layer may perform packet segmentation and reassembly to communicate via logical channels. A MAC layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer also may implement error detection techniques, error correction techniques, or both to support retransmissions to improve link efficiency. In the control plane, an RRC layer may provide establishment, configuration, and maintenance of an RRC connection between a UE 115 and a network entity 105 or a core network 130 supporting radio bearers for user plane data. A PHY layer may map transport channels to physical channels.

The UEs 115 and the network entities 105 may support retransmissions of data to increase the likelihood that data is received successfully. Hybrid automatic repeat request (HARQ) feedback is one technique for increasing the likelihood that data is received correctly via a communication link (e.g., a communication link 125, a D2D communication link 135) . HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC) ) , forward error correction (FEC) , and retransmission (e.g., automatic repeat request (ARQ) ) . HARQ may improve throughput at the MAC layer in poor radio conditions (e.g., low signal-to-noise conditions) . In some examples, a device may support same-slot HARQ feedback, in which case the device may provide HARQ feedback in a specific slot for data received via a previous symbol in the slot. In some other examples, the device may provide HARQ feedback in a subsequent slot, or according to some other time interval.

Techniques described herein support SRS transmission via an indicated TA value or a special TA value, rules and conditions for determining which TA value or which TAG, or both for SRS transmission, and mechanisms for receiving an initial TA value based on such SRS transmissions. For example, the UE 115 may apply a TA value of zero for an initial SRS transmissions, or may select a default TA value or an indicated TA value based on whether a timer for a TAG is running, based on a TCI state corresponding to a TAG, or any combination thereof. The indication of the updated initial TA value (e.g., based on the SRS signaling) may be included in an absolute TA command MAC-CE message or a MAC-CE message, and may explicitly indicate the TA value, or may indicate an offset to a previous TA value, which the UE 115 may interpret according to a current TAG or a previous TAG, a timer associated with one of the TAGs, or other rules and conditions.

FIG. 2 shows an example of a wireless communications system 200 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. Wireless communications system 200 may implement aspects of wireless communications system 100. Wireless communications system 200 may include a UE 205, a network entity 210, an uplink-only device 215, an uplink-only device 220, and an uplink-only device 225, which may be examples of the corresponding devices described herein.

For example, wireless communications system 200 may be a non-limiting example of a dense uplink deployment scenario where one or more uplink receive points are configured within the network and associated with a network entity, such as the network entity 210. To improve uplink capacity and coverage, a dense uplink deployment may provide asymmetric downlink/uplink densification. The uplink signals or channels from the UE 205 are received at the uplink receive point. Downlink signals or channels are transmitted from the network entity 210, which can also be referred to as a macro node, a central node, a serving cell, a serving base station, or similar terms. The uplink receive points may be connected to the network entity 210 via a backhaul connection. The uplink receive points may provide the uplink communications from the UE 205 to the network entity 210 via the backhaul network. The dense uplink deployment may reduce the uplink pathloss (PL) , which may be helpful when the uplink coverage area is a bottleneck. This may also improve deployment costs and complexity of the wireless network since the uplink receive points may not transmit any downlink signals. That is, the uplink receive points may receive the uplink signal from the UE 205 and send the information to the network entity 210 via the backhaul with or without some processing. The uplink-only device 215, the uplink-only device 220, and the uplink-only device 225, may be non-limiting examples of the uplink receive points in the dense uplink deployment. In some examples, the uplink only devices 220 may be referred to as uplink nodes, or uplink TRPs.

In some examples, the UE 205 may communicate with the network entity 210 (e.g., or as described herein, may also communicate with one or more uplink only devices 215) . Uplink and downlink resources may be defined based on timing interval boundaries (e.g., frame, subframe, slot, mini-slot, or symbol boundaries, among other examples) . However, transmission by one device (e.g., the UE 205) may be received later by another device (e.g., the uplink only device 215, the network entity 210, or both) due to propagation delay. To address such delays, the UE 205 may send uplink transmission according to a TA value (e.g., a time offset prior to a timing for receiving uplink transmission by a network device, such that the propagation delay is accounted for) . A TA value may apply to a timing advance group (TAG) . In some examples, the network may configure the UE 205 with multiple TAGs (e.g., a first TAG corresponding to communications with the network entity 210, and a second TAG corresponding to uplink communications via an uplink-only device 215) . The network may configure two TAGs for multi-TRP communications via (e.g., single DCI (sDCI) and multi-TRP (mTRP) configurations, where no CORESET pool index value is configured or a single CORESET pol index value is configured for the CC) .

The network entity 210 may configure the UE 205 with a TA value (e.g., to be applied to at least one of the two configured TAGs) via a control message. For example, the UE 205 may receive (e.g., from the network entity 210) an absolute TA value indicated a random access response (RAR) or an absolute TA command media access control (MAC) control element (CE) . When two TAGs are configured (e.g., for a CC) , a reserved bit in a RAR may indicate whether the TA is for the first TAG or the second TAG. For example, the RAR payload may include a field for a TA command, and a reserved bit may indicate if the TA value indicated in the TA command is for the first TAG or the second TAG.

In some examples, a TA command MAC-CE for a TAG indicates a TA value N_TA by indicating an adjustment (e.g., an offset or a difference) of a current TA value (e.g., N_{TA_old}) to a new TA value (e.g., N_{TA_new}) . For example, an absolute TA command MAC-CE may include a TA command and one or more reserved bits, or a TA command MAC-CE may include a TA command and a TAG identifier (e.g., a TAG ID) indicating to which TAG the TA value applies.

In some examples (e.g., in an uplink-dense deployment, as illustrated with reference to FIG. 2) , propagation delay to the downlink TRP (e.g., the network entity 210) and the uplink TRP (e.g., the uplink-only device 215) may be different. Because of the different propagation delays, timing alignment by the UE 205 may rely on different TA values for uplink transmissions. In some examples, in addition to a TA value, a TA offset value may be applied. For example, a TA offset value may be added to a TA value to accommodate uplink -downlink switching time at the network entity 210. For a downlink reception point (e.g., the network entity 210) , timing alignment may be improved by accounting for uplink-downlink switching time (e.g., a TA value based on propagation delay between the UE 205 and the network entity 210 may address some timing misalignment issues, but the network entity 210 may also take additional time to switch from downlink signaling to uplink signaling to successfully receive uplink signaling form the UE 205) . Thus, in some examples, the network entity 210 may configure the UE 205 with a TA offset value, which can be applied to (e.g., added to or combined with) the TA value (e.g., to address uplink-downlink switching time, in addition to addressing propagation delay) . However, the uplink-only device 215 may not perform downlink signaling, and may therefore not rely on any uplink-downlink switching time. In such examples, the UE 205 may benefit from mechanisms by which the UE 205 can determine a TA offset for the uplink receive point (e.g., which may be different than a TA value for a network entity 210) .

In some examples, according to techniques described herein, the UE 205 may determine a TA value for communicating with according to a first TAG (e.g., for communications with the network entity 210) and a second TAG (e.g., for communications with the uplink-only device 215) based on a single timing offset value. For instance, if two TAGs are configured for a CC for an uplink-only TRP, a single TA offset value (e.g., n-TimingAdvanceOffset) may be configured for the corresponding serving cell. In some examples, the single TA offset value may be applied to both TAGs (e.g., the UE 205 may communicate with the uplink-only device 215 and the network entity 210 using the same TA offset value) . In some examples, the UE 205 may apply the indicated TA offset value to one TAG (e.g., a first TAG) , and may apply a TA offset value of 0 to another TAG (e.g., the second TAG) . In such examples, the UE 205 may communicate with the network entity 210 via the first TAG (e.g., using the indicated TA offset value) , and may communicate with the uplink-only device 215 via the second TAG (e.g., using the TA offset value of 0) .

The UE 205 may select which of the two TAGs configured for the CC is the first TAG (e.g., to which the UE 205 is to apply the indicated TA offset value) and which is the second TAG (e.g., the TAG to which the UE 205 is to apply the TA offset value of 0) based on one or more rules, or conditions. For example, the first TAG may be the TAG with the highest TAG index or the lowest TAG index, the first configured TAG or second configured TAG in RRC, or the like. In some examples, the UE 205 may select the second TAG to be the TAG with the highest or lowest TAG, the TAG that is first or second configured in RRC, or the TAG that is associated with a pathloss or path loss offset that satisfies a threshold (e.g., or is the highest or lowest path loss threshold) , or the TAG that is associated with SRS resources, among other examples.

In some examples, the UE may use a TA value for uplink signaling. However, to determine such a TA value, the UE may initially transmit signaling with a TA value of 0. However, in order to transmit the PRACH, the UE may rely on configuration of an initial transmit beam on which to send the PRACH transmission. The transmit beam for PRACH signaling may be based on a corresponding receive beam of an associated downlink reference signal. However, because the uplink-only device 215 does not transmit downlink signaling, the UE 205 may not have access to any corresponding receive beam or downlink reference signal from the uplink-only device 215. Therefore, to transmit a PRACH message to the uplink-only device 215, the UE may perform some beam sweeping procedures.

In some examples, according to techniques described herein, the UE may transmit a PRACH message to a downlink reception point (e.g., the network entity 210) for initial access. After RRC connection, the UE 205 may perform beam management procedures (e.g., may transmit SRSs via SRS resources for beam management) . The SRS signaling may be used to identify a serviceable (e.g., preferred) uplink-only device 215 (e.g., the uplink-only device 215 may perform measurements and determine an updated TA value) and a good transmit/receive beam pair associated with the uplink-only device 215. In some cases, the beam management SRSs may also be used for initial TA acquisition. As described herein, the UE 205 may determine a TA value and a TAG for the TA value, and may transmit SRSs accordingly to determine an uplink-only device 215 for uplink signaling, to determine an initial TA value to use for subsequent uplink signaling, or both.

Techniques described herein (e.g., with reference to FIGs. 3-8) support transmission of beam management SRSs for TA acquisition, and techniques for determining which TAG should be used for such SRS transmissions (e.g., techniques described herein support determination of a TA value used for SRS transmissions before getting an initial TA value for the TAG) . Upon obtaining the initial TA based on the SRS, the network entity 210 may indicate the initial TA to the UE according to techniques described herein.

FIG. 3 shows an example of a timeline 300 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The timeline 300 may implement, or be implemented by, aspects of the wireless communications system 100 and the wireless communications system 200. For example, a UE (e.g., a UE 115) and one or more network entities (e.g., network entities 105, such as an uplink TRP and a downlink TRP) , which may be examples of corresponding devices described with reference to FIGs. 1-2, may communicate according to one or both of the timeline 300 and the timeline 301.

In some examples, the UE may transmit uplink signaling (e.g., PRACH signaling as part of a random access procedure) to a TRP (e.g., a downlink reception point) for initial access. After RRC connection, the UE may use beam management SRS signaling to identify a good uplink receive point (e.g., another TRP for the multi-TRP deployment, such as an uplink-only device 215) . In some examples, the beam management SRS transmissions may also be used for initial TA acquisition. Thus, to transmit the SRS for TA acquisition, the UE may determine which TAG to use for SRS signaling. prior to receiving or determining an initial TA value for the TAG, the UE may determine which TA value should be used for the SRS signaling. Upon obtaining the initial TA based on the SRS, the network may provide an initial TA (e.g., for subsequent uplink signaling via the uplink reception point) to the UE.

In some examples, as described in greater detail with reference to FIGs. 1-2, a UE may be configured with multiple (e.g., 2) TAGs. The two TAGs may be configured for a CC in a multi-TRP deployment (e.g., with an uplink-only TRP) . In such examples, the UE may determine a TAG, and a TA value, which are used for beam management SRS transmissions, based on one or more rules, conditions, or indications provided by the network.

In some examples, the UE may apply a TA value equal to 0 for transmission of the beam management SRSs 315. For instance, as illustrated with reference to timeline 300, downlink resources (e.g., for downlink 305-a) and uplink resources (e.g., for uplink 310-a) may be defined according to various timing boundaries (e.g., downlink /UL frame or subframe timing at the downlink TRP) . However, one or more other devices (e.g., the UE and the uplink TRP) may receive downlink signaling (e.g., downlink 305-a) or transmit uplink signaling (e.g., uplink 310-a) at a different timing (e.g., as a result of propagation delay, physical distance, etc. ) . Thus, the downlink TRP may transmit downlink 305-a at T1 and monitor for uplink 310-a at T2, and the UE may receive the downlink 305-a at T3 (e.g., after time delay 320 which may be referred to as t_p1) , and may transmit uplink signaling (e.g., uplink 310-a) at T4 (e.g., after the time delay 320, which may be referred to as t_p1) . The UE may transmit the SRS 315-a via the uplink resources (e.g., uplink 310-a) using an initial TA value (TA₁) of 0. In such examples, the uplink TRP may receive the SRS 315-a at a timing offset of 325 from T2 (e.g., which may be referred to as t) because the SRS 315-a may be delayed by time offset 330 after transmission at T4 (e.g., which may be referred to as t_p2) .

An updated TA values may be determined and utilized by the UE for subsequent SRS transmissions, or subsequent uplink data transmissions (e.g., the uplink TRP may measure received SRSs 315-a, calculate an updated TA value, and forward the updated TA value via backhaul signaling to the downlink TRP, which may transmit an indication of the updated TA value to the UE) . The updated TA value may be defined as 2×RTT. Thus, as illustrated with reference to timeline 300, the updated TA value (e.g., TA2) may be defined as TA2=2t_p2=2 (t-TA₁/2) .

In such examples (e.g., where TA₁=0) , the UE may use a fixed TAG for transmitting beam management SRS 315-a for selecting the uplink TRP. In such examples, a downlink reference timing (e.g., T3, or the timing at which the UE receives the downlink 305-a after offset 320 from the uplink/downlink frame timing at the downlink TRP) associated with the fixed TAG may be used (e.g., but an accumulated TA=0 is used considering the uplink TRPs may be located geographically close to the UE) . The fixed TAG may refer to a TAG that is associated with beam management SRS resources. The fixed TAG may be one of the two TAGs configured for multi-TRP communications on a CC, and the fixed TAG may be configured to be associated with the beam management SRSs 315-a as indicated in control signaling, may be the TAG with the lowest or highest index value, the TAG that is first or last configured at the UE in RRC signaling, may be indicated in one or more standards documents, or may be defined as the fixed TAG based on one or more rules or conditions. In some examples (e.g., where TA₁=0) , the beam management SRS 315-a may not be associated with any TAG. In such examples a single downlink reference timing may be used for both TAGs (e.g., both TAGs are associated with the same downlink reference timing) . In either case, the UE may transmit the SRS 315-a using a TA value of 0.

In some examples, the UE may transmit the SRS 315-b using a special (e.g., default) TA value. For example, when a timer for a TAG associated with beam management SRS is not running, a special TA value may be used. Otherwise, the indicated TA for the given TAG may be applied for transmitting the SRS 315-b. Techniques for determining the indicated TA value for a given TAG may be described in greater detail with reference to FIG. 4.

In some examples, the UE may apply a special TA value for transmission of the beam management SRSs 315. For instance, as illustrated with reference to timeline 301, downlink resources (e.g., for downlink 305-b) and uplink resources (e.g., for uplink 310-b) may be defined according to various timing boundaries (e.g., downlink/UL frame or subframe timing at the downlink TRP) . However, one or more other devices (e.g., the UE and the uplink TRP) may receive downlink signaling (e.g., downlink 305-b) or transmit uplink signaling (e.g., uplink 310-b) at a different timing (e.g., as a result of propagation delay, physical distance, etc. ) . Thus, the downlink TRP may transmit downlink 305-b at T2 and monitor for uplink 310-b at T4, and the UE may receive the downlink 305-a at T5 (e.g., after time delay 320 which may be referred to as t_p1) , and may transmit uplink signaling (e.g., uplink 310-b) at T6 (e.g., after the time delay 320, which may be referred to as t_p1) . The UE may transmit the SRS 315-b using a special initial TA value (TA₁) . The TA value may define a timing at which the UE transmits the SRS (e.g., at offset 335 prior to T6, which is the timing of uplink 310-b according to the timing at the UE) . For example, the special TA value may be set such that TA₁=2·t_p1 (e.g., the offset 335 may be referred to as that TA₁) . The UE may thus transmit the SRS 315-b at T1 according to the special TA value. The uplink TRP may receive the SRS 315-b at T3, after a timing offset of 340 from T1 (e.g., which may be referred to as t_p2) because the SRS 315-a may be delayed by time offset 345 after transmission at T1 (e.g., which may be referred to as t) .

An updated TA value may be determined and utilized by the UE for subsequent SRS transmissions, or subsequent uplink data transmissions (e.g., the uplink TRP may measure received SRSs 315-b, calculate an updated TA value, and forward the updated TA value via backhaul signaling to the downlink TRP, which may transmit an indication of the updated TA value to the UE) . The updated TA value may be defined as 2×RTT. Thus, as illustrated with reference to timeline 300, the updated TA value (e.g., TA2) may be defined as TA2=2t_p2=2 (TA₁/2-t) .

When transmitting the SRS 315 (e.g., using the special TA value) , the UE determine which TAG is associated with the beam management SRS (e.g., and to which TAG to apply the TA value) . In some examples, the TAG associated with the SRS transmission for beam management may be a fixed TAG (e.g., a TAG with the highest index value or lowest index value, a first or last configured TAG in RRC, among other examples) . The fixed TAG may be configured at the UE via control signaling, defined in one or more standards documents, or determined based on one or more conditions or rules. In some examples, the TAG associated with beam management SRSs may be the TAG that is different than the TAG indicated in a message such as a random access response (RAR) (e.g., the other TAG that is not indicated in a RAR PDSCH) . In some examples, the TAG associated with beam management SRSs for determining a TA value may be the TAG associated with an indicated uplink TCI state. For example, beam management SRSs resources may be aperiodic SRS resources, and an aperiodic SRS resource set for beam management may be configured to follow an indicated TCI state. In such example, the TAG associated with the indicated uplink TCI states may be the TAG associated with the beam management SRSs (e.g., and the TAG to which the special TA value is applied) .

In some examples, the special TA value may be set equal to 0 (e.g., similar to the TA value of 0 illustrated with reference to the timeline 300) . In some examples, the special TA value may be set equal to the TA value associated with another TAG that is different from the TAG associated with the beam management SRS. In some examples, the network may configure the UE to either use a TA value equal to 0, or to us the TA indicated after TA acquisition. For example, RRC signaling (e.g., an RRC message) may indicate that a UE is either to set a TA value equal to 0 (e.g., for the TAG associated with beam management SRS) , or to use an indicated TA (e.g., after TA acquisition as indicated by control signaling for the TAG or for another TAG) . The UE may use the special TA value according to the RRC message (e.g., 0, or the indicated TA) until otherwise configured (e.g., until another RRC message switches the TA value that the UE is to use) . Such configuration (e.g., whether to use the TA value of 0 or the indicated TA value after TA acquisition) may be per SRS resource, or per SRS resource set.

In some examples, as described in greater detail with reference to Figs. 4 and 5, the UE may apply a TA for beam management SRSs based on whether a timer (e.g., a timeAlignmentTimer) for a TAG (e.g., the TAG associated with beam management SRS) is running.

FIG. 4 shows an example of a timeline 400 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The timeline 400 may implement aspects of, or be implemented by aspects of, the wireless communications system 100, the wireless communications system 200, the timeline 300, and the timeline 301. For example, a UE may communicate with one or more network entities (e.g., network entities 105, such as an uplink TRP and a downlink TRP) , which may be examples of corresponding devices described with reference to FIGs. 1-3, according to the timeline 400.

When a timer (e.g., a timeAlignmentTimer) for the TAG that is associated with the beam management SRS is running, the UE may apply the TA for the beam management SRSs corresponding to the TAG associated with beam management SRS. For example, the network may configure SRS resources 405. In some examples, the SRS resources 405 may be periodic or semi-periodic resources. As described in greater detail with reference to FIG. 3, the UE may determine which TAG (e.g., of multiple TAGs configured for a CC) corresponds to the SRS resources. For instance, the network may configure a relationship between the SRS resources 405 and a second TAG. The UE may perform a random access procedure (e.g., with the downlink TRP in an uplink dense deployment, as described with reference to FIG. 2) . The UE may receive the RAR 410, which may include an indication of a TA value for a first TAG of the two TAGs configured for the CC. At T1 (e.g., and based on the RAR) , the UE may initiate a timer 420 (e.g., a timeAlignmentTimer) corresponding to the first TAG. The SRS resources 405-a may occur while the timer 420 is running. However, the timer 425 (e.g., a timeAlignmentTimer associated with the second TAG, which is associated with the beam management SRS transmissions) may not be running. Because the timer 425, which is associated with the second TAG, is not running during the SRS resources 405-a, the UE may transmit SRS signaling via the SRS resources 405-a using the special (e.g., default) TA value. For example, as described with reference to FIG. 3, the special TA value may be set equal to 0, or may the first TA value for the first TAG (e.g., the TAG that is different form the second TAG associated with beam management SRS) indicated in the RAR 410. Similarly, because the timer 425 is not running during the SRS resources 405-b, the UE may transmit SRSs via the SRS resources 405-b according to the special TA value (e.g., with the TA set equal to 0, or using the first TA value indicated via the RAR 410) .

The uplink TRP may receive the SRSs transmitted via the SRS resources 405-a (e.g., or the SRS resources transmitted via the SRS resources 405-b, or both) , and may forward measurement information or a selected TA value to the downlink TRP. The downlink TRP may transmit a TA command 415. The TA command 415 may include an indication of a second TA value for the second TAG. In some examples, the second TA value may be based on the SRS measurements performed by the uplink TRP. Having received the TA command 415, the UE may initiate the timer 425 at T2.

The UE may transmit SRSs via the SRS resources 405-c. Because the timer 425 is running during the SRS resources 405-c (e.g., and because the timer 425 is for the second TAG, which is associated with beam management SRS) , the UE may apply the second TA value to the SRS transmission. For example, the UE may transmit the SRSs via the SRS resources 405-c using the second TA value associated with the second TAG.

Similar techniques may apply for aperiodic SRS resources. For example, the SRS resources 405 may be aperiodic SRS resources. In such examples, if the aperiodic SRS resource set for beam management is not configured to follow a unified TCI state, then the UE may utilize the indicated TA value if the timer for the TAG associated with beam management SRSs is running (e.g., and if the timer for the TAG associated with beam management SRSs is not running, then the UE may use the default TA value) .

In some examples, the UE may use a TA value based on whether a timer (e.g., a timeAlignmentTimer) for a TAG is running, and based on a TAG Id associated with a TCI state, as described in greater detail with reference to FIG. 5.

FIG. 5 shows an example of a timeline 500 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The timeline 500 may implement aspects of, or be implemented by aspects of, the wireless communications system 100, the wireless communications system 200, the timeline 300, the timeline 301, and the timeline 400. For example, a UE may communicate with one or more network entities (e.g., network entities 105, such as an uplink TRP and a downlink TRP) , which may be examples of corresponding devices described with reference to FIGs. 1-4, according to the timeline 500.

The network may configure the UE with SRS resources 505. For example, DCIs 520 may indicate aperiodic SRS resources 505. If the aperiodic SRS resources 505 (e.g., for beam management SRS transmissions) are configured to follow a unified TCI state, then the UE may apply the indicated TA value associated with the TAG that is associated with the indicated TCI state (e.g., if a timer (e.g., a timeAlignmentTimer) for the TAG associated with beam management SRSs is running) .

For example, the UE may receive a control message (e.g., the RAR 510, or another control message such as a TA command in a MAC-CE message) , which may indicate a first TA value for at the first TAG (e.g., where two TAGs are configured for a CC, as described in greater detail with reference to FIG. 2) . The UE may communicate (e.g., transmit SRSs via the SRS resources 505) according to an indicated uplink TCI state 525-a (e.g., in which case the first TAG is associated with SRSs for beam management) . The TCI state 525-a may correspond to the first TAG. In such examples, the UE may apply the TA for beam management SRSs indicated by the RAR 510 if the timer associated with the first TAG is running. For instance, the UE may initiate the timer 530 (e.g., a timeAlignmentTimer for the first TAG) at T1 (e.g., based on receiving the RAR 510 including the first TA value for the first TAG) . While operating according to the indicated TCI state 525-a, the UE may transmit SRSs via the SRS resources 505-ausing the first TA value indicated in the RAR 510. The DCI 520-a may indicate the SRS resources 505-a, and the UE may transmit the SRSs via the SRS resources 505-a using the first TA value because the timer 530 is running during the SRS resources 505-a.

The network may also configure the UE to operate according to a second TCI state 525-b (e.g., the UE may switch from using the first TCI state 525-a to using the second TCI state 525-b as indicated by the network) . When operating according to the second TCI state 525-b, the second TAG associated with the second TCI state 525-b may be the TAG corresponding to the SRS resources. The UE may receive the DCI 520-b (e.g., while operating according to the TCI state 525-a) , which may indicate aperiodic SRS resources 505-b. The SRS resources 505-b may occur while the UE is to operate according to the TCI state 525-b, which may correspond to the second TAG. However, the second timer 535 (e.g., a timeAlignmentTimer) for the second TAG may not yet be running. Thus, because the second TCI state 525-b indicates the second TAG, but while the first timer 530 is running, the UE may transmit SRSs via the SRS resources 505-b using a default or special TA value (e.g., may set the TA value equal to 0, or may us the first TA value for the first TA value that is not currently associated with beam management SRSs) .

The UE may receive a TA command 515 (e.g., based on transmitting the SRSs via the SRS resources 505-b) . Based on the TA command, which may indicate a second TA value for the second TAG, the UE may initiate the timer 535 at T2. The DCI 520-c may indicate the SRS resources 505-c. Because the second TCI state 525-b corresponds to the second TAG, and because the second timer 535 for the second TAG is running, the UE may transmit the SRSs via the SRS resources 505-c using the second TA value (e.g., indicated in the TA command 515) .

FIG. 6 shows an example of a timeline 600 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The timeline 600 may implement aspects of, or be implemented by aspects of, the wireless communications system 100, the wireless communications system 200, the timeline 300, the timeline 301, the timeline 400, and the timeline 500. For example, a UE may communicate with one or more network entities (e.g., network entities 105, such as an uplink TRP and a downlink TRP) , which may be examples of corresponding devices described with reference to FIGs. 1-5, according to the timeline 500. The UE may be configured with two TAGs for a CC, as described herein.

In some examples, once the network obtains an initial TA based on beam management SRSs (e.g., after receving SRSs as described in greater detail with reference to FIGs. 3-6) , the network may transmit and the UE may receive an indication (e.g., a control message) of a new (e.g., initial) TA value for subsequent uplink signaling.

In some examples, the UE may receive an absolute TA command MAC-CE. The absolute TA command MAC-CE may indicate to which TAG the UE is to apply the indicated TA value. For example, the UE may receive a RAR 605, which may include a first TA value for the first TAG. Accordingly, the UE may initiate the timer 625 (e.g., a timeAlignmentTimer for the first TAG) at T1. The UE may then transmit SRSs via the SRS resources 610 (e.g., using the first TA value, as described with reference to FIGs. 3-5) . The UE may receive the TA command 615 (e.g., an absolute TA command MAC-CE) , which may include an indication of a second TA value for the second TAG. Accordingly, at T2, the UE may initiate the timer 630 (e.g., a timeAlignmentTimer for the second TAG) . Subsequently, the UE may transmit uplink signaling associated with the second TAG using the TA value indicated in the absolute TA command MAC-CE.

In some examples, a TA command MAC-CE may include a TA adjustment value. The TA adjustment value indicated in the TA command may be interpreted as relative to a TA value with respect to another TA value (e.g., a TA value associated with the other TAG that is different form the TAG indicated by the TA command MAC-CE) . The UE may interpret the TA value in the TA command as an adjustment value relative to another (e.g., previously configured) TA value if one or more conditions are satisfied. For example, the UE may interpret the TA command as a relative TA value with respect to another TA value if the TAG ID in the TA command MAC-CE corresponds to a TAG associated with beam management SRS. In some examples, the UE may interpret the TA command as a relative TA value with respect to another TA value if the TAG ID indicated in the TA command corresponds to the TAG that is different form the TAG ID indicated by the RAR 605 (e.g., the UE may assume that the PRACH is directed toward the downlink TRP) .

In some examples, the UE may interpret the TA command as a relative TA value with respect to a latest TA associated with the same TAG indicated in the TA command MAC-CE if the TAG ID indicated in the TA command MAC-CE corresponds to a different TAG from the TAG associated with the beam management SRS. the UE may interpret the TA command as a relative TA value with respect to a latest TA associated with the same TAG indicated in the TA command MAC-CE if the TAG ID indicated in the TA command MAC-CE corresponds to the same TAG indicated by the RAR PDSCH.

For example, the UE may receive the RAR 605, which may include an indication of a first TA value for the first TAG. Accordingly, the UE may initiate the timer 625 (e.g., the timeAlignmentTimer for the first TAG) at T1. The UE may transmit SRSs via the SRS resources 610 (e.g., using the first TA value as described in greater detail with reference to FIGs. 3-6) . Based on the SRS resources, the UE may receive a TA command 615. The TA command 615 may include a TA value, and may indicate the second TAG. The UE may interpret the TA command for the second TAG as a first timing adjustment value relative to the first TA value indicated via the RAR 605, in the case the TA value associated with the second TAG is equal to the first TA value plus the first timing adjustment value. The UE may initiate the timer 630 (e.g., a timeAlignmentTimer for the second TAG) at T2, and may transmit any uplink signaling associated with the second TAG using the TA value interpreted from the TA command 615. In some examples, the UE may receive a TA command 620, which may indicate a second TA adjustment value and the first TAG. The UE may interpret the the TA command 620 as a second timing adjustment value relative to the first TA value (e.g., indicated via the RAR 605) . At T3, the UE may reinitiate the time 625.

FIG. 7 shows an example of a timeline 700 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The timeline 700 may implement aspects of, or be implemented by aspects of, the wireless communications system 100, the wireless communications system 200, the timeline 300, the timeline 301, the timeline 400, the timeline 500, and the timeline 600. For example, a UE may communicate with one or more network entities (e.g., network entities 105, such as an uplink TRP and a downlink TRP) , which may be examples of corresponding devices described with reference to FIGs. 1-6, according to the timeline 600. The UE may be configured with two TAGs for a CC, as described herein.

In some examples, once the network obtains an initial TA based on beam management SRSs (e.g., after transmitting SRSs as described in greater detail with reference to FIGs. 3-6) , the network may transmit and the UE may receive an indication (e.g., a control message) of a new (e.g., initial) TA value for subsequent uplink signaling. The first TA command MAC-CE may indicate a TA adjustment value relative to the TA value associated with the other TAG that is different from the TAG indicated by the TA command MAC-CE, and the remaining TA command Mac-CE indicates a TA relative to the TA value associated with the same TAG indicated by the TA command MAC-CE. The first TA command MAC-CE may refer to as an earliest TA command MAC-CE that indicates a specific TAG ID when the timer associated with the specific TAG is not running. For example, the specific TAG may be the TAG associated with the beam management SRSs, or the TAG that is different from the TAG indicated by the RAR PDSCH.

For example, the UE may receive a RAR 705. The RAR 705 may include an indication of a first TA value for the first TAG. The UE may initiate the timer 730 (e.g., a timeAlignmentTimer for the first TAG) . The UE may transmit SRSs via the SRS resources 710 (e.g., using the TA value indicated in the RAR 705) . The UE may receive the TA command 715 (e.g., a TA command MAC-CE) indicating the first TAG and including a first TA adjustment value. The TA value for the first TAG indicated in the TA command 715 may be interpreted as the previous TA value (e.g., indicated in the RAR 705) plus the first TA adjustment value indicated in the TA command 715 because the timeAlignmentTimer 730 is running when the TA command 715 is received or applied. At T2, the UE may reinitiate the timer 730 based on receiving the TA command 715.

The UE may receive the TA command 720 (e.g., based on having transmitted the SRSs via the SRS resources 710) . The TA command may include a second TA adjustment value, and may indicate the second TAG. The UE may interpret the TA command 720 as the first TA value (associated with the first TAG which is different from the second TAG indicated in TA command 720) plus the second TA adjustment value because the timeAlignmentTimer is not running when the TA command 720 (e.g., a TA command MAC-CE) is received or applied. Based on the TA command 720, the UE may initiate the timer 735 (e.g., a timeAlignmentTimer for the second TAG) at T3.

The UE may receive the TA command 725, which may include a third TA adjustment value and an indication of the second TAG. The UE may interpret the TA value for the second TAG as the previously indicated second TA value (e.g., the TA value interpreted from the TA command 720) plus the third TA adjustment value. At T4, the UE may reinitiate the timer 735, and subsequent uplink communications associated with the second TAG may be transmitted according to the TA value interpreted from the TA command 725.

FIG. 8 shows an example of a process flow 800 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The process flow 800 may implement, or be implemented by, aspects of the wireless communications system 100, the wireless communications system 200, the timeline 300, the timeline 301, the timeline 400, the timeline of 500, the timeline 600, the timeline 600, and the timeline 700. For example, the process flow 800 may include a UE 805, a network entity 810, and an uplink-only device 815 (e.g., another network entity configured for or deployed for uplink signaling in an uplink-dense deployment) .

At 820, the UE 805 may receive control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the CC. In some examples, a CORESET pool index may not be configured for the CORESET on the CC, or a single CORESET pool index value may be configured for the CORESETs on the CC. For example, as described with reference to FIG. 2, if two TAGs are configured for a CC with UL-only TRP, a single n-TimingAdvanceOffset can be configured for the serving cell

At 825, the UE 805 may apply a first TA value to the first TAG and a second TA value to a second TAG.

At 830, the UE 805 may transmit (e.g., via the CC) , uplink signaling to the network (e.g., the UE 805 may transmit the uplink signaling to the network agnostically, without determining that the UE 805 is transmitting the uplink signaling via the uplink-only device 815) . The uplink signaling may correspond to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

In some examples, as described in greater detail with reference to FIG. 2, the first TA value may be a sum of a first delay value (e.g., based on or twice a RTT) and the TA offset value, and the second TA value may be a sum of a second TA value, and the same TA offset value (e.g., the TA offset value is applied to both the first and second TAG. In some examples, the first TA value may include the first delay value and the TA offset value, and the second TA value may include the second delay value and a TA offset value of 0 (e.g., the TA offset value is only applied to one TAG, and a TA value of 0 is applied to the other) . The UE 805 may determine to which TAG to apply the TA offset value of 0 based on one or more rules or conditions.

FIG. 9 shows an example of a process flow 900 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The process flow 900 may implement, or be implemented by, aspects of the wireless communications system 100, the wireless communications system 200, the timeline 300, the timeline 301, the timeline 400, the timeline of 500, the timeline 600, the timeline 600, the timeline 700, and the process flow 800. For example, the process flow 900 may include a UE 905, a network entity 910, and an uplink-only device 915 (e.g., another network entity configured for or deployed for uplink signaling in an uplink-dense deployment) .

At 920, the UE 905 may receive control signaling indicating a first TAG and a second TAG for a component carrier. At 930, the UE 9056 may select a first TA value, and a first TAG or the second TAG for beam management SRSs transmissions. For example, as described in greater detail with reference to FIG. 3-5, When two TAGs are configured for a CC configured with an UL-only TRP, the UE 805 determines the TAG and TA value that is used for beam management SRSs based on a TA value of 0 or a special TA value. The TAG associated with beam management is determined as a fixed or preconfigured TAG, or based on a timer (e.g., a timeAlignmentTimer) for a given TAG or a preconfigured association between the SRS and the TAG.

At 935, the UE 905 may transmit SRSs (e.g., to the uplink-only device 915) .

In some examples, the UE 905 may set the first TA value equal to 0, and may select the first TAG. In such examples, transmissions at 935 may be based on the first TA value.

In some examples, at 925, the UE 905 may receive second control signaling indicating the first TA value corresponding to the first TAG, and the first TAG may correspond to SRS resources for beam management. For example, as described with reference to FIGs. 3-5, when a timeAlignmentTimer for a TAG associated with SRS is running, the indicated TA may be applied. In such examples, the UE 905 may initiate the timer corresponding to the first TAG. In such examples, selecting the first TA value is based on the timer running. In some examples, when the timeAlignmentTimer for the TAG associated with the SRS is not running, a special or default TA value is used. For example, selecting the TA value may include selecting the first TA value equal to a default or special value based on a determination that the timer corresponding to the first TA group is not running (e.g., because the timer has not been triggered or because the triggered timer has been run and has expired) . In some examples, selecting the first TAG or the second TAG maybe based on one or more rules or conditions (e.g., order, timing, index value, etc., of the TAGs) .

The UE 905 may receive (e.g., via control signaling at 920, or other control signaling) , RRC signaling indicating whether the UE is to monitor for control signaling indicating TA values, or is to apply a TA value of 0.

FIG. 10 shows an example of a process flow 1000 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The process flow 1000 may implement, or be implemented by, aspects of the wireless communications system 100, the wireless communications system 200, the timeline 300, the timeline 301, the timeline 400, the timeline of 500, the timeline 600, the timeline 600, the timeline 700, the process flow 800, and the process flow 900. For example, the process flow 1000 may include a UE 1005, a network entity 1010, and an uplink-only device 1015 (e.g., another network entity configured for or deployed for uplink signaling in an uplink-dense deployment) .

At 1020, the UE 1005 may transmit SRSs (e.g., which may be received by the uplink-only device 1015) . The UE 1005 may transmit the SRSs for beam management via a first set of SRS resources according to a first TA value. At 1025, the UE 1005 may receive (e.g., from the network entity 1010) a control message including an indication of a second TA value corresponding to the first TAG, as described in greater detail with reference to FIGs. 6-7.

In some examples, the control message may be a MAC-CE including a TA command indicating the second TA value. In some examples, the MAC-CE may include a field indicating the first TAG (e.g., a reserved bit indicating to which TAG the TA command applies. In some examples, the TA command may be included in a MAC-CE and may indicate an offset value from another TA value, as described in greater detail with reference to FIGs. 6-7.

AT 1030, the UE 1005 may apply the TA value (e.g., indicated in the control signaling received at 1025, interpreted per the rules or conditions described herein) . At 1035, the UE 1005 may transmit uplink signaling according to the applied TA value and via the corresponding TAG.

FIG. 11 shows a block diagram 1100 of a device 1105 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The device 1105 may be an example of aspects of a UE 115 as described herein. The device 1105 may include a receiver 1110, a transmitter 1115, and a communications manager 1120. The device 1105, or one or more components of the device 1105 (e.g., the receiver 1110, the transmitter 1115, and the communications manager 1120) , may include at least one processor, which may be coupled with at least one memory, to, individually or collectively, support or enable the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1110 may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to multiple TA values for uplink dense deployments) . Information may be passed on to other components of the device 1105. The receiver 1110 may utilize a single antenna or a set of multiple antennas.

The transmitter 1115 may provide a means for transmitting signals generated by other components of the device 1105. For example, the transmitter 1115 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to multiple TA values for uplink dense deployments) . In some examples, the transmitter 1115 may be co-located with a receiver 1110 in a transceiver module. The transmitter 1115 may utilize a single antenna or a set of multiple antennas.

The communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations thereof or various components thereof may be examples of means for performing various aspects of multiple TA values for uplink dense deployments as described herein. For example, the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be capable of performing one or more of the functions described herein.

In some examples, the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be implemented in hardware (e.g., in communications management circuitry) . The hardware may include at least one of a processor, a digital signal processor (DSP) , a central processing unit (CPU) , an application-specific integrated circuit (ASIC) , a field-programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure. In some examples, at least one processor and at least one memory coupled with the at least one processor may be configured to perform one or more of the functions described herein (e.g., by one or more processors, individually or collectively, executing instructions stored in the at least one memory) .

Additionally, or alternatively, the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be implemented in code (e.g., as communications management software or firmware) executed by at least one processor. If implemented in code executed by at least one processor, the functions of the communications manager 1120, the receiver 1110, the transmitter 1115, or various combinations or components thereof may be performed by a general-purpose processor, a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices (e.g., configured as or otherwise supporting, individually or collectively, a means for performing the functions described in the present disclosure) .

In some examples, the communications manager 1120 may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 1110, the transmitter 1115, or both. For example, the communications manager 1120 may receive information from the receiver 1110, send information to the transmitter 1115, or be integrated in combination with the receiver 1110, the transmitter 1115, or both to obtain information, output information, or perform various other operations as described herein.

The communications manager 1120 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1120 is capable of, configured to, or operable to support a means for receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier. The communications manager 1120 is capable of, configured to, or operable to support a means for applying, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG. The communications manager 1120 is capable of, configured to, or operable to support a means for transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

Additionally, or alternatively, the communications manager 1120 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1120 is capable of, configured to, or operable to support a means for receiving control signaling indicating a first TAG and a second TAG for a component carrier. The communications manager 1120 is capable of, configured to, or operable to support a means for selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling. The communications manager 1120 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

Additionally, or alternatively, the communications manager 1120 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1120 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value. The communications manager 1120 is capable of, configured to, or operable to support a means for receiving, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG. The communications manager 1120 is capable of, configured to, or operable to support a means for applying the second TA value to the first TAG. The communications manager 1120 is capable of, configured to, or operable to support a means for transmitting uplink signaling according to the second TA value and the first TAG.

By including or configuring the communications manager 1120 in accordance with examples as described herein, the device 1105 (e.g., at least one processor controlling or otherwise coupled with the receiver 1110, the transmitter 1115, the communications manager 1120, or a combination thereof) may support techniques for transmissions using TA values resulting in reduced processing, reduced power consumption, more reliable signaling, and improved user experience.

FIG. 12 shows a block diagram 1200 of a device 1205 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The device 1205 may be an example of aspects of a device 1105 or a UE 115 as described herein. The device 1205 may include a receiver 1210, a transmitter 1215, and a communications manager 1220. The device 1205, or one of more components of the device 1205 (e.g., the receiver 1210, the transmitter 1215, and the communications manager 1220) , may include at least one processor, which may be coupled with at least one memory, to support the described techniques. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1210 may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to multiple TA values for uplink dense deployments) . Information may be passed on to other components of the device 1205. The receiver 1210 may utilize a single antenna or a set of multiple antennas.

The transmitter 1215 may provide a means for transmitting signals generated by other components of the device 1205. For example, the transmitter 1215 may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to multiple TA values for uplink dense deployments) . In some examples, the transmitter 1215 may be co-located with a receiver 1210 in a transceiver module. The transmitter 1215 may utilize a single antenna or a set of multiple antennas.

The device 1205, or various components thereof, may be an example of means for performing various aspects of multiple TA values for uplink dense deployments as described herein. For example, the communications manager 1220 may include a TAG configuration manager 1225, a TA value manager 1230, an uplink signaling manager 1235, an SRS manager 1240, a TA command manager 1245, or any combination thereof. The communications manager 1220 may be an example of aspects of a communications manager 1120 as described herein. In some examples, the communications manager 1220, or various components thereof, may be configured to perform various operations (e.g., receiving, obtaining, monitoring, outputting, transmitting) using or otherwise in cooperation with the receiver 1210, the transmitter 1215, or both. For example, the communications manager 1220 may receive information from the receiver 1210, send information to the transmitter 1215, or be integrated in combination with the receiver 1210, the transmitter 1215, or both to obtain information, output information, or perform various other operations as described herein.

The communications manager 1220 may support wireless communications in accordance with examples as disclosed herein. The TAG configuration manager 1225 is capable of, configured to, or operable to support a means for receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier. The TA value manager 1230 is capable of, configured to, or operable to support a means for applying, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG. The uplink signaling manager 1235 is capable of, configured to, or operable to support a means for transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

Additionally, or alternatively, the communications manager 1220 may support wireless communications in accordance with examples as disclosed herein. The TAG configuration manager 1225 is capable of, configured to, or operable to support a means for receiving control signaling indicating a first TAG and a second TAG for a component carrier. The TA value manager 1230 is capable of, configured to, or operable to support a means for selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling. The SRS manager 1240 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

Additionally, or alternatively, the communications manager 1220 may support wireless communications in accordance with examples as disclosed herein. The SRS manager 1240 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value. The TA command manager 1245 is capable of, configured to, or operable to support a means for receiving, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG. The TA value manager 1230 is capable of, configured to, or operable to support a means for applying the second TA value to the first TAG. The uplink signaling manager 1235 is capable of, configured to, or operable to support a means for transmitting uplink signaling according to the second TA value and the first TAG.

FIG. 13 shows a block diagram 1300 of a communications manager 1320 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The communications manager 1320 may be an example of aspects of a communications manager 1120, a communications manager 1220, or both, as described herein. The communications manager 1320, or various components thereof, may be an example of means for performing various aspects of multiple TA values for uplink dense deployments as described herein. For example, the communications manager 1320 may include a TAG configuration manager 1325, a TA value manager 1330, an uplink signaling manager 1335, an SRS manager 1340, a TA command manager 1345, a timer manager 1350, an RRC manager 1355, or any combination thereof. Each of these components, or components or subcomponents thereof (e.g., one or more processors, one or more memories) , may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The communications manager 1320 may support wireless communications in accordance with examples as disclosed herein. The TAG configuration manager 1325 is capable of, configured to, or operable to support a means for receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier. The TA value manager 1330 is capable of, configured to, or operable to support a means for applying, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG. The uplink signaling manager 1335 is capable of, configured to, or operable to support a means for transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

In some examples, the first TA value includes a sum of a first delay value and the TA offset value, and the second TA value includes a sum of a second delay value and the TA offset value.

In some examples, the first TA value includes a sum of a first delay value and the TA offset value. In some examples, the second TA value includes a sum of a second delay value and a second TA offset value that is equal to zero.

In some examples, the control signaling includes a first index value corresponding to the first TAG, and a second index value corresponding to the second TAG. In some examples, applying the second TA value including the sum of the second delay value and the second TA offset value that is equal to zero to the second TAG is based on the first index value being lower or higher than the second index value.

In some examples, the control signaling includes a first indication of the first TAG and a second indication of a second TAG. In some examples, applying the second TA value including the sum of the second delay value and the second TA offset value that is equal to zero to the second TAG is based on the second TAG corresponding to the first TAG or the second TAG.

In some examples, applying the second TA value including the sum of the second delay value and the second TA offset value that is equal to zero to the second TAG is based on a pathloss value, a pathloss offset, or an source sounding reference signal resource being associated with the first TAG.

Additionally, or alternatively, the communications manager 1320 may support wireless communications in accordance with examples as disclosed herein. In some examples, the TAG configuration manager 1325 is capable of, configured to, or operable to support a means for receiving control signaling indicating a first TAG and a second TAG for a component carrier. In some examples, the TA value manager 1330 is capable of, configured to, or operable to support a means for selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling. The SRS manager 1340 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

In some examples, to support selecting the first TA value, the TA value manager 1330 is capable of, configured to, or operable to support a means for setting the first TA value equal to zero, where the first TAG is selected and where transmitting the first set of one or more sounding reference signals according to the first TA value is based on a downlink reference timing corresponding to the first TAG.

In some examples, the TA command manager 1345 is capable of, configured to, or operable to support a means for receiving second control signaling including an indication of the first TA value corresponding to the first TAG, where the first TAG corresponds to the first set of one or more sounding reference signals for beam management. In some examples, the timer manager 1350 is capable of, configured to, or operable to support a means for initiating, based on receiving the second control signaling, a time alignment timer corresponding to the first TAG, where selecting the first TA value is based on initiating the time alignment timer and a relationship between the set of sounding reference signal resources and the first TAG.

In some examples, to support selecting the first TA value, the TA value manager 1330 is capable of, configured to, or operable to support a means for selecting the first TA value equal to a default value is based on a determination that a time alignment timer corresponding to the first TAG is not running.

In some examples, the default value corresponds to a TA value of the second TAG.

In some examples, the default value is equal to zero.

In some examples, selecting the one of the first TAG or the second TAG is based on an order of configuration of the first TAG and the second TAG, an index value of the first TAG and an index value of the second TAG, an indication in the control signaling of a relationship between a set of sounding reference signals and the first TAG or the second TAG, or any combination thereof.

In some examples, the RRC manager 1355 is capable of, configured to, or operable to support a means for receiving a random access response message indicating the second TAG, where selecting the one of the first TAG or the second TAG is based on the random access response message indicating the second TAG.

In some examples, the TAG configuration manager 1325 is capable of, configured to, or operable to support a means for receiving second control signaling activating or indicating a first transmission configuration indicator state corresponding with the first TAG, where selecting the first TAG is based on receiving the second control signaling.

In some examples, the RRC manager 1355 is capable of, configured to, or operable to support a means for receiving a radio resource control message indicating that the UE is to set the first TA value equal to zero, or indicating that the UE is to monitor for a control message indicating the first TA value, and where selecting the first TA value is based on receiving the radio resource control message.

In some examples, the TA value manager 1330 is capable of, configured to, or operable to support a means for receiving, based on transmitting the first set of one or more sounding reference signals, second control signaling indicating a second TA value corresponding to the first TAG, where the first TAG corresponds to the first set of one or more sounding reference signals for beam management. In some examples, the SRS manager 1340 is capable of, configured to, or operable to support a means for transmitting a second set of one or more sounding reference signals for beam management via the set of sounding reference signal resources of the component carrier according to the second TA value and the first TAG.

Additionally, or alternatively, the communications manager 1320 may support wireless communications in accordance with examples as disclosed herein. In some examples, the SRS manager 1340 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value. The TA command manager 1345 is capable of, configured to, or operable to support a means for receiving, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG. In some examples, the TA value manager 1330 is capable of, configured to, or operable to support a means for applying the second TA value to the first TAG. In some examples, the uplink signaling manager 1335 is capable of, configured to, or operable to support a means for transmitting uplink signaling according to the second TA value and the first TAG.

In some examples, the control message includes a MAC-CE including a TA command indicating the second TA value.

In some examples, the MAC-CE includes a field indicating the first TAG.

In some examples, the control message includes a MAC-CE including a TA command indicating an offset value from a third TA value associated with a second TAG. In some examples, the second TA value is based on the offset value.

In some examples, the second TAG is a different TAG from the first TAG indicated in the MAC-CE, the first TAG indicated in the MAC-CE corresponding to the first TAG associated with the one or more sounding reference signal resources for beam management.

In some examples, the TA command manager 1345 is capable of, configured to, or operable to support a means for receiving a random access response message indicating a TA value for a second TAG, where the second TAG is a different TAG from the first TAG indicated in the MAC-CE, the first TAG being different than the second TAG indicated by the random access response message.

In some examples, the second TAG is a different TAG from the first TAG indicated in MAC-CE, the MAC-CE being an earliest MAC-CE indicating the first TAG when a time alignment timer corresponding to the first TAG is not running.

FIG. 14 shows a diagram of a system 1400 including a device 1405 that supports multiple TA values for uplink dense deployments in accordance with one or more aspects of the present disclosure. The device 1405 may be an example of or include the components of a device 1105, a device 1205, or a UE 115 as described herein. The device 1405 may communicate (e.g., wirelessly) with one or more network entities 105, one or more UEs 115, or any combination thereof. The device 1405 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager 1420, an input/output (I/O) controller 1410, a transceiver 1415, an antenna 1425, at least one memory 1430, code 1435, and at least one processor 1440. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., a bus 1445) .

The I/O controller 1410 may manage input and output signals for the device 1405. The I/O controller 1410 may also manage peripherals not integrated into the device 1405. In some cases, the I/O controller 1410 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 1410 may utilize an operating system such as or another known operating system. Additionally or alternatively, the I/O controller 1410 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 1410 may be implemented as part of one or more processors, such as the at least one processor 1440. In some cases, a user may interact with the device 1405 via the I/O controller 1410 or via hardware components controlled by the I/O controller 1410.

In some cases, the device 1405 may include a single antenna 1425. However, in some other cases, the device 1405 may have more than one antenna 1425, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver 1415 may communicate bi-directionally, via the one or more antennas 1425, wired, or wireless links as described herein. For example, the transceiver 1415 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1415 may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas 1425 for transmission, and to demodulate packets received from the one or more antennas 1425. The transceiver 1415, or the transceiver 1415 and one or more antennas 1425, may be an example of a transmitter 1115, a transmitter 1215, a receiver 1110, a receiver 1210, or any combination thereof or component thereof, as described herein.

The at least one memory 1430 may include random access memory (RAM) and read-only memory (ROM) . The at least one memory 1430 may store computer-readable, computer-executable code 1435 including instructions that, when executed by the at least one processor 1440, cause the device 1405 to perform various functions described herein. The code 1435 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, the code 1435 may not be directly executable by the at least one processor 1440 but may cause a computer (e.g., when compiled and executed) to perform functions described herein. In some cases, the at least one memory 1430 may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The at least one processor 1440 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the at least one processor 1440 may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the at least one processor 1440. The at least one processor 1440 may be configured to execute computer-readable instructions stored in a memory (e.g., the at least one memory 1430) to cause the device 1405 to perform various functions (e.g., functions or tasks supporting multiple TA values for uplink dense deployments) . For example, the device 1405 or a component of the device 1405 may include at least one processor 1440 and at least one memory 1430 coupled with or to the at least one processor 1440, the at least one processor 1440 and at least one memory 1430 configured to perform various functions described herein. In some examples, the at least one processor 1440 may include multiple processors and the at least one memory 1430 may include multiple memories. One or more of the multiple processors may be coupled with one or more of the multiple memories, which may, individually or collectively, be configured to perform various functions herein. In some examples, the at least one processor 1440 may be a component of a processing system, which may refer to a system (such as a series) of machines, circuitry (including, for example, one or both of processor circuitry (which may include the at least one processor 1440) and memory circuitry (which may include the at least one memory 1430) ) , or components, that receives or obtains inputs and processes the inputs to produce, generate, or obtain a set of outputs. The processing system may be configured to perform one or more of the functions described herein. For example, the at least one processor 1440 or a processing system including the at least one processor 1440 may be configured to, configurable to, or operable to cause the device 1405 to perform one or more of the functions described herein. Further, as described herein, being “configured to, ” being “configurable to, ” and being “operable to” may be used interchangeably and may be associated with a capability, when executing code stored in the at least one memory 1430 or otherwise, to perform one or more of the functions described herein.

The communications manager 1420 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1420 is capable of, configured to, or operable to support a means for receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier. The communications manager 1420 is capable of, configured to, or operable to support a means for applying, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG. The communications manager 1420 is capable of, configured to, or operable to support a means for transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

Additionally, or alternatively, the communications manager 1420 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1420 is capable of, configured to, or operable to support a means for receiving control signaling indicating a first TAG and a second TAG for a component carrier. The communications manager 1420 is capable of, configured to, or operable to support a means for selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling. The communications manager 1420 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

Additionally, or alternatively, the communications manager 1420 may support wireless communications in accordance with examples as disclosed herein. For example, the communications manager 1420 is capable of, configured to, or operable to support a means for transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value. The communications manager 1420 is capable of, configured to, or operable to support a means for receiving, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG. The communications manager 1420 is capable of, configured to, or operable to support a means for applying the second TA value to the first TAG. The communications manager 1420 is capable of, configured to, or operable to support a means for transmitting uplink signaling according to the second TA value and the first TAG.

By including or configuring the communications manager 1420 in accordance with examples as described herein, the device 1405 may support techniques for TA selection and use resulting in improved communication reliability, reduced latency, improved user experience related to reduced processing, reduced power consumption, more efficient utilization of communication resources, improved coordination between devices, longer battery life, improved throughput, and improved user experience.

In some examples, the communications manager 1420 may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver 1415, the one or more antennas 1425, or any combination thereof. Although the communications manager 1420 is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager 1420 may be supported by or performed by the at least one processor 1440, the at least one memory 1430, the code 1435, or any combination thereof. For example, the code 1435 may include instructions executable by the at least one processor 1440 to cause the device 1405 to perform various aspects of multiple TA values for uplink dense deployments as described herein, or the at least one processor 1440 and the at least one memory 1430 may be otherwise configured to, individually or collectively, perform or support such operations.

FIG. 15 shows a flowchart illustrating a method 1500 that supports multiple TA values for uplink dense deployments in accordance with aspects of the present disclosure. The operations of the method 1500 may be implemented by a UE or its components as described herein. For example, the operations of the method 1500 may be performed by a UE 115 as described with reference to FIGs. 1 through 14. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At 1505, the method may include receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, where a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier. The operations of block 1505 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1505 may be performed by a TAG configuration manager 1325 as described with reference to FIG. 13.

At 1510, the method may include applying, based on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG. The operations of block 1510 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1510 may be performed by a TA value manager 1330 as described with reference to FIG. 13.

At 1515, the method may include transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value. The operations of block 1515 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1515 may be performed by an uplink signaling manager 1335 as described with reference to FIG. 13.

FIG. 16 shows a flowchart illustrating a method 1600 that supports multiple TA values for uplink dense deployments in accordance with aspects of the present disclosure. The operations of the method 1600 may be implemented by a UE or its components as described herein. For example, the operations of the method 1600 may be performed by a UE 115 as described with reference to FIGs. 1 through 14. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At 1605, the method may include receiving control signaling indicating a first TAG and a second TAG for a component carrier. The operations of block 1605 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1605 may be performed by a TAG configuration manager 1325 as described with reference to FIG. 13.

At 1610, the method may include selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling. The operations of block 1610 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1610 may be performed by a TA value manager 1330 as described with reference to FIG. 13.

At 1615, the method may include transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG. The operations of block 1615 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1615 may be performed by an SRS manager 1340 as described with reference to FIG. 13.

FIG. 17 shows a flowchart illustrating a method 1700 that supports multiple TA values for uplink dense deployments in accordance with aspects of the present disclosure. The operations of the method 1700 may be implemented by a UE or its components as described herein. For example, the operations of the method 1700 may be performed by a UE 115 as described with reference to FIGs. 1 through 14. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally, or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At 1705, the method may include transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value. The operations of block 1705 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1705 may be performed by an SRS manager 1340 as described with reference to FIG. 13.

At 1710, the method may include receiving, based on transmitting the first set of one or more sounding reference signals, a control message including an indication of a second TA value corresponding to a first TAG. The operations of block 1710 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1710 may be performed by a TA command manager 1345 as described with reference to FIG. 13.

At 1715, the method may include applying the second TA value to the first TAG. The operations of block 1715 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1715 may be performed by a TA value manager 1330 as described with reference to FIG. 13.

At 1720, the method may include transmitting uplink signaling according to the second TA value and the first TAG. The operations of block 1720 may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of 1720 may be performed by an uplink signaling manager 1335 as described with reference to FIG. 13.

The following provides an overview of aspects of the present disclosure:

Aspect 1: A method for wireless communications at a UE, comprising: receiving control signaling indicating a component carrier corresponding to a first TAG and a second TAG, and indicating a TA offset value for the component carrier, wherein a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier; applying, based at least in part on the TA offset value, a first TA value to the first TAG and a second TA value to the second TAG; and transmitting, via the component carrier, uplink signaling to a network corresponding to the first TAG using the first TA value and uplink signaling to the network corresponding to the second TAG using the second TA value.

Aspect 2: The method of aspect 1, wherein the first TA value comprises a sum of a first delay value and the TA offset value, and the second TA value comprises a sum of a second delay value and the TA offset value.

Aspect 3: The method of any of aspects 1 through 2, wherein the first TA value comprises a sum of a first delay value and the TA offset value, and the second TA value comprises a sum of a second delay value and a second TA offset value that is equal to zero.

Aspect 4: The method of aspect 3, wherein the control signaling comprises a first index value corresponding to the first TAG, and a second index value corresponding to the second TAG, applying the second TA value comprising the sum of the second delay value and the second TA offset value that is equal to zero to the second TAG is based at least in part on the first index value being lower or higher than the second index value.

Aspect 5: The method of any of aspects 3 through 4, wherein the control signaling comprises a first indication of the first TAG and a second indication of a second TAG, applying the second TA value comprising the sum of the second delay value and the second TA offset value that is equal to zero to the second TAG is based at least in part on the second TAG corresponding to the first TAG or the second TAG.

Aspect 6: The method of any of aspects 3 through 5, wherein applying the second TA value comprising the sum of the second delay value and the second TA offset value that is equal to zero to the second TAG is based at least in part on a pathloss value, a pathloss offset, or an source sounding reference signal resource being associated with the first TAG.

Aspect 7: A method for wireless communications at a UE, comprising: receiving control signaling indicating a first TAG and a second TAG for a component carrier; selecting a first TA value and one of the first TAG or the second TAG for beam management sounding reference signaling; and transmitting a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first TA value and the selected one of the first TAG or the second TAG.

Aspect 8: The method of aspect 7, wherein selecting the first TA value comprises: setting the first TA value equal to zero, wherein the first TAG is selected and wherein transmitting the first set of one or more sounding reference signals according to the first TA value is based at least in part on a downlink reference timing corresponding to the first TAG.

Aspect 9: The method of any of aspects 7 through 8, further comprising: receiving second control signaling comprising an indication of the first TA value corresponding to the first TAG, wherein the first TAG corresponds to the first set of one or more sounding reference signals for beam management; and initiating, based at least in part on receiving the second control signaling, a time alignment timer corresponding to the first TAG, wherein selecting the first TA value is based at least in part on initiating the time alignment timer and a relationship between the set of sounding reference signal resources and the first TAG.

Aspect 10: The method of any of aspects 7 through 9, wherein selecting the first TA value comprises: selecting the first TA value equal to a default value is based at least in part on a determination that a time alignment timer corresponding to the first TAG is not running.

Aspect 11: The method of aspect 10, wherein the default value corresponds to a TA value of the second TAG.

Aspect 12: The method of any of aspects 10 through 11, wherein the default value is equal to zero.

Aspect 13: The method of any of aspects 7 through 12, wherein selecting the one of the first TAG or the second TAG is based at least in part on an order of configuration of the first TAG and the second TAG, an index value of the first TAG and an index value of the second TAG, an indication in the control signaling of a relationship between a set of sounding reference signals and the first TAG or the second TAG, or any combination thereof.

Aspect 14: The method of any of aspects 7 through 13, further comprising: receiving a random access response message indicating the second TAG, wherein selecting the one of the first TAG or the second TAG is based at least in part on the random access response message indicating the second TAG.

Aspect 15: The method of any of aspects 7 through 14, further comprising: receiving second control signaling activating or indicating a first transmission configuration indicator state corresponding with the first TAG, wherein selecting the first TAG is based at least in part on receiving the second control signaling.

Aspect 16: The method of any of aspects 7 through 15, further comprising: receiving a radio resource control message indicating that the UE is to set the first TA value equal to zero, or indicating that the UE is to monitor for a control message indicating the first TA value, and wherein selecting the first TA value is based at least in part on receiving the radio resource control message.

Aspect 17: The method of any of aspects 7 through 16, further comprising: receiving, based at least in part on transmitting the first set of one or more sounding reference signals, second control signaling indicating a second TA value corresponding to the first TAG, wherein the first TAG corresponds to the first set of one or more sounding reference signals for beam management; and transmitting a second set of one or more sounding reference signals for beam management via the set of sounding reference signal resources of the component carrier according to the second TA value and the first TAG.

Aspect 18: A method for wireless communications at a UE, comprising: transmitting a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first TA value; receiving, based at least in part on transmitting the first set of one or more sounding reference signals, a control message comprising an indication of a second TA value corresponding to a first TAG; applying the second TA value to the first TAG; and transmitting uplink signaling according to the second TA value and the first TAG.

Aspect 19: The method of aspect 18, wherein the control message comprises a MAC-CE comprising a TA command indicating the second TA value.

Aspect 20: The method of aspect 19, wherein the MAC-CE comprises a field indicating the first TAG.

Aspect 21: The method of any of aspects 18 through 20, wherein the control message comprises a MAC-CE comprising a TA command indicating an offset value from a third TA value associated with a second TAG, and the second TA value is based at least in part on the offset value.

Aspect 22: The method of aspect 21, wherein the second TAG is a different TAG from the first TAG indicated in the MAC-CE, the first TAG indicated in the MAC-CE corresponding to the first TAG associated with the one or more sounding reference signal resources for beam management.

Aspect 23: The method of any of aspects 21 through 22, further comprising: receiving a random access response message indicating a TA value for a second TAG, wherein the second TAG is a different TAG from the first TAG indicated in the MAC-CE, the first TAG being different than the second TAG indicated by the random access response message.

Aspect 24: The method of any of aspects 21 through 23, wherein the second TAG is a different TAG from the first TAG indicated in MAC-CE, the MAC-CE being an earliest MAC-CE indicating the first TAG when a time alignment timer corresponding to the first TAG is not running.

Aspect 25: A UE for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to perform a method of any of aspects 1 through 6.

Aspect 26: A UE for wireless communications, comprising at least one means for performing a method of any of aspects 1 through 6.

Aspect 27: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 1 through 6.

Aspect 28: A UE for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to perform a method of any of aspects 7 through 17.

Aspect 29: A UE for wireless communications, comprising at least one means for performing a method of any of aspects 7 through 17.

Aspect 30: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 7 through 17.

Aspect 31: A UE for wireless communications, comprising one or more memories storing processor-executable code, and one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to perform a method of any of aspects 18 through 24.

Aspect 32: A UE for wireless communications, comprising at least one means for performing a method of any of aspects 18 through 24.

Aspect 33: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by one or more processors to perform a method of any of aspects 18 through 24.

It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.

Information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed using a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor but, in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) . Any functions or operations described herein as being capable of being performed by a processor may be performed by multiple processors that, individually or collectively, are capable of performing the described functions or operations.

The functions described herein may be implemented using hardware, software executed by a processor, firmware, or any combination thereof. If implemented using software executed by a processor, the functions may be stored as or transmitted using one or more instructions or code of a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one location to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc. Disks may reproduce data magnetically, and discs may reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media. Any functions or operations described herein as being capable of being performed by a memory may be performed by multiple memories that, individually or collectively, are capable of performing the described functions or operations.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

As used herein, including in the claims, the article “a” before a noun is open-ended and understood to refer to “at least one” of those nouns or “one or more” of those nouns. Thus, the terms “a, ” “at least one, ” “one or more, ” “at least one of one or more” may be interchangeable. For example, if a claim recites “a component” that performs one or more functions, each of the individual functions may be performed by a single component or by any combination of multiple components. Thus, the term “acomponent” having characteristics or performing functions may refer to “at least one of one or more components” having a particular characteristic or performing a particular function. Subsequent reference to a component introduced with the article “a” using the terms “the” or “said” may refer to any or all of the one or more components. For example, a component introduced with the article “a” may be understood to mean “one or more components, ” and referring to “the component” subsequently in the claims may be understood to be equivalent to referring to “at least one of the one or more components. ” Similarly, subsequent reference to a component introduced as “one or more components” using the terms “the” or “said” may refer to any or all of the one or more components. For example, referring to “the one or more components” subsequently in the claims may be understood to be equivalent to referring to “at least one of the one or more components. ”

The term “determine” or “determining” encompasses a variety of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information) , accessing (e.g., accessing data stored in memory) and the like. Also, “determining” can include resolving, obtaining, selecting, choosing, establishing, and other such similar actions.

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A user equipment (UE) , comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to:

receive control signaling indicating a component carrier corresponding to a first timing advance group and a second timing advance group, and indicating a timing advance offset value for the component carrier, wherein a control resource set pool index is not configured for one or more control resource sets on the component carrier or a single control resource set pool index value is configured for the one or more control resource sets on the component carrier;

apply, based at least in part on the timing advance offset value, a first timing advance value to the first timing advance group and a second timing advance value to the second timing advance group; and

transmit, via the component carrier, uplink signaling to a network corresponding to the first timing advance group using the first timing advance value and uplink signaling to the network corresponding to the second timing advance group using the second timing advance value.
The UE of claim 1, wherein the first timing advance value comprises a sum of a first delay value and the timing advance offset value, and the second timing advance value comprises a sum of a second delay value and the timing advance offset value.
The UE of claim 1, wherein:

the first timing advance value comprises a sum of a first delay value and the timing advance offset value, and

the second timing advance value comprises a sum of a second delay value and a second timing advance offset value that is equal to zero.
The UE of claim 3, wherein:

the control signaling comprises a first index value corresponding to the first timing advance group, and a second index value corresponding to the second timing advance group, the second timing advance value comprising the sum of the second delay value and the second timing advance offset value that is equal to zero to the second timing advance group is based at least in part on the first index value being lower or higher than the second index value.
The UE of claim 3, wherein:

the control signaling comprises a first indication of the first timing advance group and a second indication of a second timing advance group, the second timing advance value comprising the sum of the second delay value and the second timing advance offset value that is equal to zero to the second timing advance group is based at least in part on the second timing advance group corresponding to the first timing advance group or the second timing advance group.
The UE of claim 3, wherein application of the second timing advance value comprising the sum of the second delay value and the second timing advance offset value that is equal to zero to the second timing advance group is based at least in part on a pathloss value, a pathloss offset, or an source sounding reference signal resource being associated with the first timing advance group.
A user equipment (UE) , comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to:

receive control signaling indicating a first timing advance group and a second timing advance group for a component carrier;

select a first timing advance value and one of the first timing advance group or the second timing advance group for beam management sounding reference signaling; and

transmit a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first timing advance value and the selected one of the first timing advance group or the second timing advance group.
The UE of claim 7, wherein, to select the first timing advance value, the one or more processors are individually or collectively operable to execute the code to cause the UE to:

set the first timing advance value equal to zero, wherein the first timing advance group is selected and wherein transmission of the first set of one or more sounding reference signals according to the first timing advance value is based at least in part on a downlink reference timing corresponding to the first timing advance group.
The UE of claim 7, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive second control signaling comprising an indication of the first timing advance value corresponding to the first timing advance group, wherein the first timing advance group corresponds to the first set of one or more sounding reference signals for beam management; and

initiate, based at least in part on the second control signaling, a time alignment timer corresponding to the first timing advance group, wherein selection of the first timing advance value is based at least in part on initiating the time alignment timer and a relationship between the set of sounding reference signal resources and the first timing advance group.
The UE of claim 7, wherein, to select the first timing advance value, the one or more processors are individually or collectively operable to execute the code to cause the UE to:

select the first timing advance value equal to a default value is based at least in part on a determination that a time alignment timer corresponding to the first timing advance group is not running.
The UE of claim 10, wherein the default value corresponds to a timing advance value of the second timing advance group.
The UE of claim 10, wherein:

the default value is equal to zero.
The UE of claim 7, wherein selection of the one of the first timing advance group or the second timing advance group is based at least in part on an order of configuration of the first timing advance group and the second timing advance group, an index value of the first timing advance group and an index value of the second timing advance group, an indication in the control signaling of a relationship between a set of sounding reference signals and the first timing advance group or the second timing advance group, or any combination thereof.
The UE of claim 7, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive a random access response message indicating the second timing advance group, wherein selection of the one of the first timing advance group or the second timing advance group is based at least in part on the random access response message indicating the second timing advance group.
The UE of claim 7, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive second control signaling activating or indicating a first transmission configuration indicator state corresponding with the first timing advance group, wherein selection of the first timing advance group is based at least in part on the second control signaling.
The UE of claim 7, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive a radio resource control message indicating that the UE is to set the first timing advance value equal to zero, or indicating that the UE is to monitor for a control message indicating the first timing advance value, and wherein selection of the first timing advance value is based at least in part on the radio resource control message.
The UE of claim 7, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive, based at least in part on transmission of the first set of one or more sounding reference signals, second control signaling indicating a second timing advance value corresponding to the first timing advance group, wherein the first timing advance group corresponds to the first set of one or more sounding reference signals for beam management; and

transmit a second set of one or more sounding reference signals for beam management via the set of sounding reference signal resources of the component carrier according to the second timing advance value and the first timing advance group.
A user equipment (UE) , comprising:

one or more memories storing processor-executable code; and

one or more processors coupled with the one or more memories and individually or collectively operable to execute the code to cause the UE to:

transmit a first set of one or more sounding reference signals for beam management via a first set of sounding reference signal resources according to a first timing advance value;

receive, based at least in part on transmission of the first set of one or more sounding reference signals, a control message comprising an indication of a second timing advance value corresponding to a first timing advance group;

apply the second timing advance value to the first timing advance group; and

transmit uplink signaling according to the second timing advance value and the first timing advance group.
The UE of claim 18, wherein the control message comprises a media access control control element comprising a timing advance command indicating the second timing advance value.
The UE of claim 19, wherein the media access control control element comprises a field indicating the first timing advance group.
The UE of claim 18, wherein:

the control message comprises a media access control control element comprising a timing advance command indicating an offset value from a third timing advance value associated with a second timing advance group, and

the second timing advance value is based at least in part on the offset value.
The UE of claim 21, wherein the second timing advance group is a different timing advance group from the first timing advance group indicated in the media access control control element, the first timing advance group indicated in the media access control control element corresponding to the first timing advance group associated with the one or more sounding reference signal resources for beam management.
The UE of claim 21, wherein the one or more processors are individually or collectively further operable to execute the code to cause the UE to:

receive a random access response message indicating a timing advance value for a second timing advance group, wherein the second timing advance group is a different timing advance group from the first timing advance group indicated in the media access control control element, the first timing advance group being different than the second timing advance group indicated by the random access response message.
The UE of claim 21, wherein the second timing advance group is a different timing advance group from the first timing advance group indicated in media access control control element, the media access control control element being an earliest media access control control element indicating the first timing advance group when a time alignment timer corresponding to the first timing advance group is not running.
A user equipment (UE) , comprising:

a processing system that includes processor circuitry and memory circuitry that stores code, the processing system configured to cause the UE to:

receive control signaling indicating a first timing advance group and a second timing advance group for a component carrier;

select a first timing advance value and one of the first timing advance group or the second timing advance group for beam management sounding reference signaling; and

transmit a first set of one or more sounding reference signals for beam management via a set of sounding reference signal resources of the component carrier according to the first timing advance value and the selected one of the first timing advance group or the second timing advance group.
The UE of claim 25, wherein, to select the first timing advance value, the processing system is configured to cause the UE to:

set the first timing advance value equal to zero, wherein the first timing advance group is selected and wherein transmission of the first set of one or more sounding reference signals according to the first timing advance value is based at least in part on a downlink reference timing corresponding to the first timing advance group.
The UE of claim 25, wherein the processing system is further configured to cause the UE to:

receive second control signaling comprising an indication of the first timing advance value corresponding to the first timing advance group, wherein the first timing advance group corresponds to the first set of one or more sounding reference signals for beam management; and

initiate, based at least in part on the second control signaling, a time alignment timer corresponding to the first timing advance group, wherein selection of the first timing advance value is based at least in part on initiating the time alignment timer and a relationship between the set of sounding reference signal resources and the first timing advance group.
The UE of claim 25, wherein, to select the first timing advance value, the processing system is configured to cause the UE to:

select the first timing advance value equal to a default value is based at least in part on a determination that a time alignment timer corresponding to the first timing advance group is not running.
The UE of claim 25, wherein selection of the one of the first timing advance group or the second timing advance group is based at least in part on an order of configuration of the first timing advance group and the second timing advance group, an index value of the first timing advance group and an index value of the second timing advance group, an indication in the control signaling of a relationship between a set of sounding reference signals and the first timing advance group or the second timing advance group, or any combination thereof.
The UE of claim 25, wherein the processing system is further configured to cause the UE to:

receive a random access response message indicating the second timing advance group, wherein selecting the one of the first timing advance group or the second timing advance group is based at least in part on the random access response message indicating the second timing advance group.