WO2022061579A1

WO2022061579A1 - Performance of secondary cell group adding procedures or handover or redirection procedures

Info

Publication number: WO2022061579A1
Application number: PCT/CN2020/117111
Authority: WO
Inventors: Shouqiao ZHU; Kaikai YANG; Haojun WANG; Jian Li; Ruiqi QIAN; Jie Ren
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2020-09-23
Filing date: 2020-09-23
Publication date: 2022-03-31
Anticipated expiration: 2023-03-23

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit an indication of one or more layer 2 measurements associated with a first radio access technology (RAT). The UE may selectively perform, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a dual connectivity (DC) mode associated with the first RAT and a second RAT with which the UE is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a secondary cell group (SCG) adding procedure, or the SCG adding procedure to add the SCG via the first RAT. Numerous other aspects are provided.

Description

PERFORMANCE OF SECONDARY CELL GROUP ADDING PROCEDURES OR HANDOVER OR REDIRECTION PROCEDURES

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for performance of secondary cell group adding procedures or handover or redirection procedures.

BACKGROUND

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, and/or the like) . Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, orthogonal frequency-division multiple access (OFDMA) systems, single-carrier frequency-division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and Long Term Evolution (LTE) . LTE/LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP) .

A wireless network may include a number of base stations (BSs) that can support communication for a number of user equipment (UEs) . A user equipment (UE) may communicate with a base station (BS) via the downlink and uplink. The downlink (or forward link) refers to the communication link from the BS to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail herein, a BS may be referred to as a Node B, a gNB, an access point (AP) , a radio head, a transmit receive point (TRP) , a New Radio (NR) BS, a 5G Node B, and/or the like.

The above multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different user equipment to communicate on a municipal, national, regional, and even global level. New Radio (NR) , which may also be referred to as 5G, is a set of enhancements to the LTE mobile standard promulgated by the Third Generation Partnership Project (3GPP) . NR is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM) on the downlink (DL) , using CP-OFDM and/or SC-FDM (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM) ) on the uplink (UL) , as well as supporting beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR, and other radio access technologies remain useful.

SUMMARY

In some aspects, a method of wireless communication performed by a user equipment (UE) includes transmitting an indication of one or more layer 2 measurements associated with a first radio access technology (RAT) ; and selectively performing, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a dual connectivity (DC) mode associated with the first RAT and a second RAT with which the UE is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a secondary cell group (SCG) adding procedure, or the SCG adding procedure to add the SCG via the first RAT.

In some aspects, a UE for wireless communication includes a memory and one or more processors operatively coupled to the memory, the memory and the one or more processors configured to: transmit an indication of one or more layer 2 measurements associated with a first RAT; and selectively perform, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the UE is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a SCG adding procedure, or the SCG adding procedure to add the SCG via the first RAT.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a UE, cause the UE to: transmit an indication of one or more layer 2 measurements associated with a first RAT; and selectively perform, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the UE is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a SCG adding procedure, or the SCG adding procedure to add the SCG via the first RAT.

In some aspects, an apparatus for wireless communication includes means for transmitting an indication of one or more layer 2 measurements associated with a first RAT; and means for selectively performing, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the apparatus is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a SCG adding procedure, or the SCG adding procedure to add the SCG via the first RAT.

Aspects generally include a method, apparatus, system, computer program product, non-transitory computer-readable medium, user equipment, base station, wireless communication device, and/or processing system as substantially described herein with reference to and as illustrated by the drawings and specification.

The foregoing has outlined rather broadly the features and technical advantages of examples according to the disclosure in order that the detailed description that follows may be better understood. Additional features and advantages will be described hereinafter. The conception and specific examples disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. Characteristics of the concepts disclosed herein, both their organization and method of operation, together with associated advantages will be better understood from the following description when considered in connection with the accompanying figures. Each of the figures is provided for the purposes of illustration and description, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the above-recited features of the present disclosure can be understood in detail, a more particular description, briefly summarized above, may be had by reference to aspects, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only certain typical aspects of this disclosure and are therefore not to be considered limiting of its scope, for the description may admit to other equally effective aspects. The same reference numbers in different drawings may identify the same or similar elements.

Fig. 1 is a diagram illustrating an example of a wireless network, in accordance with various aspects of the present disclosure.

Fig. 2 is a diagram illustrating an example of a base station in communication with a UE in a wireless network, in accordance with various aspects of the present disclosure.

Fig. 3 is a diagram illustrating an example of a determination of whether to perform layer 2 measurements, in accordance with various aspects of the present disclosure.

Figs. 4 and 5 are diagrams illustrating examples associated with performance of secondary cell group adding procedures or handover or redirection procedures, in accordance with various aspects of the present disclosure.

Fig. 6 is a diagram illustrating an example process associated with performance of secondary cell group adding procedures or handover or redirection procedures, in accordance with various aspects of the present disclosure.

Fig. 7 is a block diagram of an example apparatus for wireless communication, in accordance with various aspects of the present disclosure.

DETAILED DESCRIPTION

Various aspects of the disclosure are described more fully hereinafter with reference to the accompanying drawings. This disclosure may, however, be embodied in many different forms and should not be construed as limited to any specific structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Based on the teachings herein, one skilled in the art should appreciate that the scope of the disclosure is intended to cover any aspect of the disclosure disclosed herein, whether implemented independently of or combined with any other aspect of the disclosure. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, the scope of the disclosure is intended to cover such an apparatus or method which is practiced using other structure, functionality, or structure and functionality in addition to or other than the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of a claim.

Several aspects of telecommunication systems will now be presented with reference to various apparatuses and techniques. These apparatuses and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, and/or the like (collectively referred to as “elements” ) . These elements may be implemented using hardware, software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

It should be noted that while aspects may be described herein using terminology commonly associated with a 5G or NR RAT, aspects of the present disclosure can be applied to other RATs, such as a 3G RAT, a 4G RAT, and/or a RAT subsequent to 5G (e.g., 6G) .

Fig. 1 is a diagram illustrating an example of a wireless network 100, in accordance with various aspects of the present disclosure. The wireless network 100 may be or may include elements of a 5G (NR) network, an LTE network, and/or the like. The wireless network 100 may include a number of base stations 110 (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A base station (BS) is an entity that communicates with user equipment (UEs) and may also be referred to as an NR BS, a Node B, a gNB, a 5G node B (NB) , an access point, a transmit receive point (TRP) , and/or the like. Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to a coverage area of a BS and/or a BS subsystem serving this coverage area, depending on the context in which the term is used.

A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or another type of cell. A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having association with the femto cell (e.g., UEs in a closed subscriber group (CSG) ) . A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In the example shown in Fig. 1, a BS 110a may be a macro BS for a macro cell 102a, a BS 110b may be a pico BS for a pico cell 102b, and a BS 110c may be a femto BS for a femto cell 102c. A BS may support one or multiple (e.g., three) cells. The terms “eNB” , “base station” , “NR BS” , “gNB” , “TRP” , “AP” , “node B” , “5G NB” , and “cell” may be used interchangeably herein.

In some aspects, a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS. In some aspects, the BSs may be interconnected to one another and/or to one or more other BSs or network nodes (not shown) in the wireless network 100 through various types of backhaul interfaces such as a direct physical connection, a virtual network, and/or the like using any suitable transport network.

Wireless network 100 may also include relay stations. A relay station is an entity that can receive a transmission of data from an upstream station (e.g., a BS or a UE) and send a transmission of the data to a downstream station (e.g., a UE or a BS) . A relay station may also be a UE that can relay transmissions for other UEs. In the example shown in Fig. 1, a relay BS 110d may communicate with macro BS 110a and a UE 120d in order to facilitate communication between BS 110a and UE 120d. A relay BS may also be referred to as a relay station, a relay base station, a relay, and/or the like.

Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BSs, pico BSs, femto BSs, relay BSs, and/or the like. These different types of BSs may have different transmit power levels, different coverage areas, and different impacts on interference in wireless network 100. For example, macro BSs may have a high transmit power level (e.g., 5 to 40 watts) whereas pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts) .

A network controller 130 may couple to a set of BSs and may provide coordination and control for these BSs. Network controller 130 may communicate with the BSs via a backhaul. The BSs may also communicate with one another, e.g., directly or indirectly via a wireless or wireline backhaul.

UEs 120 (e.g., 120a, 120b, 120c) may be dispersed throughout wireless network 100, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, a terminal, a mobile station, a subscriber unit, a station, and/or the like. A UE may be a cellular phone (e.g., a smart phone) , a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, biometric sensors/devices, wearable devices (smart watches, smart clothing, smart glasses, smart wrist bands, smart jewelry (e.g., smart ring, smart bracelet) ) , an entertainment device (e.g., a music or video device, or a satellite radio) , a vehicular component or sensor, smart meters/sensors, industrial manufacturing equipment, a global positioning system device, or any other suitable device that is configured to communicate via a wireless or wired medium.

Some UEs may be considered machine-type communication (MTC) or evolved or enhanced machine-type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, and/or the like, that may communicate with a base station, another device (e.g., remote device) , or some other entity. A wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link. Some UEs may be considered Internet-of-Things (IoT) devices, and/or may be implemented as NB-IoT (narrowband internet of things) devices. Some UEs may be considered a Customer Premises Equipment (CPE) . UE 120 may be included inside a housing that houses components of UE 120, such as processor components, memory components, and/or the like. In some aspects, the processor components and the memory components may be coupled together. For example, the processor components (e.g., one or more processors) and the memory components (e.g., a memory) may be operatively coupled, communicatively coupled, electronically coupled, electrically coupled, and/or the like.

In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a particular RAT and may operate on one or more frequencies. A RAT may also be referred to as a radio technology, an air interface, and/or the like. A frequency may also be referred to as a carrier, a frequency channel, and/or the like. Each frequency may support a single RAT in a given geographic area in order to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using a base station 110 as an intermediary to communicate with one another) . For example, the UEs 120 may communicate using peer-to-peer (P2P) communications, device-to-device (D2D) communications, a vehicle-to-everything (V2X) protocol (e.g., which may include a vehicle-to-vehicle (V2V) protocol, a vehicle-to-infrastructure (V2I) protocol, and/or the like) , a mesh network, and/or the like. In this case, the UE 120 may perform scheduling operations, resource selection operations, and/or other operations described elsewhere herein as being performed by the base station 110.

Devices of wireless network 100 may communicate using the electromagnetic spectrum, which may be subdivided based on frequency or wavelength into various classes, bands, channels, and/or the like. For example, devices of wireless network 100 may communicate using an operating band having a first frequency range (FR1) , which may span from 410 MHz to 7.125 GHz, and/or may communicate using an operating band having a second frequency range (FR2) , which may span from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as a “sub-6 GHz” band. Similarly, FR2 is often referred to as a “millimeter wave” band despite being different from the extremely high frequency (EHF) band (30 GHz –300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band. Thus, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like, if used herein, may broadly represent frequencies less than 6 GHz, frequencies within FR1, and/or mid-band frequencies (e.g., greater than 7.125 GHz) . Similarly, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like, if used herein, may broadly represent frequencies within the EHF band, frequencies within FR2, and/or mid-band frequencies (e.g., less than 24.25 GHz) . It is contemplated that the frequencies included in FR1 and FR2 may be modified, and techniques described herein are applicable to those modified frequency ranges.

As indicated above, Fig. 1 is provided as an example. Other examples may differ from what is described with regard to Fig. 1.

Fig. 2 is a diagram illustrating an example 200 of a base station 110 in communication with a UE 120 in a wireless network 100, in accordance with various aspects of the present disclosure. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T ≥ 1 and R ≥ 1.

At base station 110, a transmit processor 220 may receive data from a data source 212 for one or more UEs, select one or more modulation and coding schemes (MCS) for each UE based at least in part on channel quality indicators (CQIs) received from the UE, process (e.g., encode and modulate) the data for each UE based at least in part on the MCS (s) selected for the UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and/or the like) and control information (e.g., CQI requests, grants, upper layer signaling, and/or the like) and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals (e.g., a cell-specific reference signal (CRS) , a demodulation reference signal (DMRS) , and/or the like) and synchronization signals (e.g., the primary synchronization signal (PSS) and secondary synchronization signal (SSS) ) . A transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, the overhead symbols, and/or the reference symbols, if applicable, and may provide T output symbol streams to T modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM and/or the like) to obtain an output sample stream. Each modulator 232 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. T downlink signals from modulators 232a through 232t may be transmitted via T antennas 234a through 234t, respectively.

At UE 120, antennas 252a through 252r may receive the downlink signals from base station 110 and/or other base stations and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM and/or the like) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. A receive processor 258 may process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller/processor 280. The term “controller/processor” may refer to one or more controllers, one or more processors, or a combination thereof. A channel processor may determine reference signal received power (RSRP) , received signal strength indicator (RSSI) , reference signal received quality (RSRQ) , channel quality indicator (CQI) , and/or the like. In some aspects, one or more components of UE 120 may be included in a housing 284.

Network controller 130 may include communication unit 294, controller/processor 290, and memory 292. Network controller 130 may include, for example, one or more devices in a core network. Network controller 130 may communicate with base station 110 via communication unit 294.

On the uplink, at UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports that include RSRP, RSSI, RSRQ, CQI, and/or the like) from controller/processor 280. Transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from transmit processor 264 may be precoded by a TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for DFT-s-OFDM, CP-OFDM, and/or the like) , and transmitted to base station 110. In some aspects, the UE 120 includes a transceiver. The transceiver may include any combination of antenna (s) 252, modulators and/or demodulators 254, MIMO detector 256, receive processor 258, transmit processor 264, and/or TX MIMO processor 266. The transceiver may be used by a processor (e.g., controller/processor 280) and memory 282 to perform aspects of any of the methods described herein, for example, as described with reference to Figs. 4-6.

At base station 110, the uplink signals from UE 120 and other UEs may be received by antennas 234, processed by demodulators 232, detected by a MIMO detector 236 if applicable, and further processed by a receive processor 238 to obtain decoded data and control information sent by UE 120. Receive processor 238 may provide the decoded data to a data sink 239 and the decoded control information to controller/processor 240. Base station 110 may include communication unit 244 and communicate to network controller 130 via communication unit 244. Base station 110 may include a scheduler 246 to schedule UEs 120 for downlink and/or uplink communications. In some aspects, the base station 110 includes a transceiver. The transceiver may include any combination of antenna (s) 234, modulators and/or demodulators 232, MIMO detector 236, receive processor 238, transmit processor 220, and/or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller/processor 240) and memory 242 to perform aspects of any of the methods described herein, for example, as described with reference to Figs. 4-6.

Controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform one or more techniques associated with performance of secondary cell group adding procedures or handover or redirection procedures, as described in more detail elsewhere herein. For example, controller/processor 240 of base station 110, controller/processor 280 of UE 120, and/or any other component (s) of Fig. 2 may perform or direct operations of, for example, process 600 of Fig. 6 and/or other processes as described herein.

Memories

242 and 282 may store data and program codes for base station 110 and UE 120, respectively. In some aspects, memory 242 and/or memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code, program code, and/or the like) for wireless communication. For example, the one or more instructions, when executed (e.g., directly, or after compiling, converting, interpreting, and/or the like) by one or more processors of the base station 110 and/or the UE 120, may cause the one or more processors, the UE 120, and/or the base station 110 to perform or direct operations of, for example, process 600 of Fig. 6 and/or other processes as described herein. In some aspects, executing instructions may include running the instructions, converting the instructions, compiling the instructions, interpreting the instructions, and/or the like.

In some aspects, the UE includes means for transmitting an indication of one or more layer 2 measurements associated with a first RAT, and/or means for selectively performing, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the UE is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a SCG adding procedure, or the SCG adding procedure to add the SCG via the first RAT. The means for the UE to perform operations described herein may include, for example, antenna 252, demodulator 254, MIMO detector 256, receive processor 258, transmit processor 264, TX MIMO processor 266, modulator 254, controller/processor 280, and/or memory 282.

In some aspects, the UE includes means for receiving, via the second RAT, a configuration for performing measurement of the one or more layer 2 measurements associated with the first RAT.

In some aspects, the UE includes means for receiving the indication to not enter the DC mode associated with the first RAT and the second RAT, and/or means for performing, after receiving the indication to not enter the DC mode, measurement of the one or more layer 2 measurements associated with the first RAT.

In some aspects, the UE includes means for performing, independently from receiving or not receiving the indication to not enter the DC mode, the handover or redirection from the second RAT to the first RAT based at least in part on the access command associated with the first RAT comprising the indication to perform the handover or the redirection.

In some aspects, the UE includes means for performing, based at least in part on receiving the indication to not enter the DC mode, transmission of the indication of the failure of the SCG adding procedure.

In some aspects, the UE includes means for performing, based at least in part on not receiving the indication to not enter the DC mode, the SCG adding procedure.

While blocks in Fig. 2 are illustrated as distinct components, the functions described above with respect to the blocks may be implemented in a single hardware, software, or combination component or in various combinations of components. For example, the functions described with respect to the transmit processor 264, the receive processor 258, and/or the TX MIMO processor 266 may be performed by or under the control of controller/processor 280.

As indicated above, Fig. 2 is provided as an example. Other examples may differ from what is described with regard to Fig. 2.

Fig. 3 is a diagram illustrating an example of a determination of whether to perform layer 2 measurements, in accordance with various aspects of the present disclosure. As shown in Fig. 3, a UE may determine whether to perform layer 2 measurements for a first RAT (e.g., NR) when connected to a second RAT (e.g., LTE) .

As shown by reference number 305, the UE may access the second RAT cell of a network. For example, the UE may access an LTE cell of a network. As shown by reference number 310, the UE may receive a first RAT measurement configuration from the network. The UE may determine whether a silence DC mode is active. For example, the UE may determine whether upper layer signaling indicates to turn off a non-standalone (NSA) mode via a silence DC mode interface.

As shown by reference number 315, when the silence DC mode is active (e.g., NSA mode is turned off) , the UE may ignore layer 2 (L2) measurements for the first RAT. In other words, based at least in part on the silence DC mode being active, the UE may prune a measurement report object associated with the layer 2 measurements for the first RAT, fail to perform the layer 2 measurements, and/or fail to report the layer 2 measurements.

As shown by reference number 320, when the silence DC mode is inactive, the UE may perform the layer 2 measurements for the first RAT and report the L2 measurements. This may allow the UE to perform an NSA SCG adding process.

As indicated above, Fig. 3 is provided as an example. Other examples may differ from what is described with regard to Fig. 3.

Based at least in part on the UE failing to perform layer 2 measurements when the silence DC mode is active, the UE may not report the layer 2 measurements that a base station may use to determine whether the UE is to perform a handover or redirection process. In other words, based at least in part on the network indicating to not enter a DC mode, the UE may be unable to provide layer 2 measurements that may indicate that the UE should handover or redirect from the second RAT to the first RAT. This may interfere with spectrum efficiency gains and/or bandwidth gains, among other examples, that may be associated with the UE being handed over from the second RAT to the first RAT.

In some aspects described herein, a UE may be configured to perform layer 2 measurements associated with a first RAT whether or not a DC silence mode is active. In other words, the UE may not prune a measurement report object associated with the layer 2 measurements when the silence DC mode is active. In some aspects, the UE may be configured to perform layer 2 measurements and reporting procedures under any circumstances associated with a dual connectivity mode indication. After the UE transmits a layer 2 measurement report and receives an access command from a network associated with a second RAT, the UE may execute a corresponding access process associated with the first RAT according to the access command and/or a status value of the silence DC mode field. In this way, the UE may perform a handover or redirection from the second RAT to the first RAT, which may improve spectral efficiency, improve bandwidth, and/or conserve computing, network, and/or communication resources for communications with a base station of the network.

Fig. 4 is a diagram illustrating an example 400 associated with performance of secondary cell group adding procedures or handover or redirection procedures, in accordance with various aspects of the present disclosure. As shown in Fig. 4, a UE (e.g., UE 120) may communicate with a base station (e.g., base station 110) . The UE and the base station may be part of a wireless network (e.g., wireless network 100) . In some aspects, the UE and the base station may communicate via a second RAT. In some aspects, the UE and the base station may perform one or more procedures associated with a DC mode, using a first RAT and the second RAT, and/or a handover or redirection from the second RAT to the first RAT. In some aspects, the first RAT may include a 5G NR RAT. In some aspects, the second RAT may include an Evolved Universal Terrestrial Radio Access (E-UTRA) RAT.

As shown by reference number 405, the UE may receive, and the base station may transmit, configuration information. In some aspects, the UE may receive configuration information from another device (e.g., from another base station and/or another UE) and/or a communication standard, among other examples. In some aspects, the UE may receive the configuration information via one or more of radio resource control (RRC) signaling, medium access control (MAC) signaling (e.g., MAC control elements (MAC CEs) ) , and/or the like. In some aspects, the configuration information may include an indication of one or more configuration parameters (e.g., already known to the UE) for selection by the UE, explicit configuration information for the UE to use to configure the UE, and/or the like.

In some aspects, the configuration information may indicate that the UE is to perform layer 2 measurements associated with a first RAT whether or not a DC silence mode is active. In some aspects, the configuration information may indicate that the UE is to report the layer 2 measurements whether or not a DC silence mode is active (e.g., based at least in part on whether or not the UE receives an indication to not enter the DC mode) .

In some aspects, the configuration information may indicate that the UE is to perform a handover or redirection from a second RAT to the first RAT based at least in part on an access command associated with the first RAT including an indication to perform the handover or the redirection (e.g., independently from receiving or not receiving an indication to not enter the DC mode) . In some aspects, the configuration information may indicate that the UE is to perform a transmission of an indication of a failure of an SCG adding procedure (e.g., based at least in part on the UE receiving the indication to not enter the DC mode) . In some aspects, the configuration information may indicate that the UE is to perform, based at least in part on the UE not receiving the indication to not enter the DC mode, an SCG adding procedure to begin operation in a DC mode by adding, to a connection via the second RAT, a connection via the first RAT as an SCG.

As shown by reference number 410, the UE may configure the UE. In some aspects, the UE may configure the UE based at least in part on the configuration information. In some aspects, the UE may be configured to perform one or more operations described herein.

As shown by reference number 415, the UE may receive, and the base station may transmit, a configuration for performing one or more layer 2 measurements associated with a first RAT and/or an indication of whether to enter a DC mode associated with the first RAT and a second RAT. In other words, the UE may receive one or more messages that indicate a configuration for performing measurement of the one or more layer 2 measurements associated with the first RAT and/or an indication of whether to enter a DC mode associated with the first RAT and a second RAT.

As shown by reference number 420, the UE may receive, and the base station may transmit, signaling for one or more layer 2 measurements associated with the first RAT. For example, the UE may receive one or more system information blocks (SIBs) , synchronization signal blocks (SSBs) , and/or reference signals, among other examples.

As shown by reference number 425, the UE may perform the one or more layer 2 measurements. For example, the UE may measure packet delay, among other examples. In some aspects, the UE may perform measurement of the one or more layer 2 measurements associated with the first RAT after receiving the indication to not enter the DC mode.

As shown by reference number 430, the UE may transmit, and the base station may receive, an indication of the one or more layer 2 measurements associated with the first RAT. In some aspects, the UE may transmit the indication of the one or more layer 2 measurements via the second RAT.

As shown by reference number 435, the UE may receive, and the base station may transmit, an access command associated with the first RAT. In some aspects, the access command may include an indication to perform the SCG adding procedure, or an indication to perform the handover or the redirection from the second RAT to the first RAT, among other examples.

As shown by reference number 440, the UE may select an action based at least in part on reception of an access command associated with the first RAT and/or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the UE is connected. For example, the UE may select one or more actions described below with reference to reference numbers 445-455.

As shown by reference number 445, the UE may perform a handover or redirection from the second RAT to the first RAT. In some aspects, the UE may establish a new standalone connection via the second RAT and release an existing connection with the first RAT. In some aspects, the UE may perform the handover or the redirection independently from receiving or not receiving the indication to not enter the DC mode.

As shown by reference number 450, the UE may transmit, and the base station may receive (e.g., via the second RAT) , an indication of a failure of an SCG adding procedure. In some aspects, the UE may perform transmission of the indication of the failure of the SCG adding procedure based at least in part on receiving the indication to not enter the DC mode. In some aspects, the indication of the failure of the SCG adding procedure includes an indication of a synchronization reconfiguration failure (e.g., SyncReconfigFailure) .

As shown by reference number 455, the UE may perform an SCG adding procedure to add a connection, via the first RAT as an SCG, to a connection via the second RAT. In some aspects, the UE may perform the SCG adding procedure based at least in part on not receiving the indication to not enter the DC mode and/or receiving an indication to enter the DC mode.

Based at least in part on the UE performing layer 2 measurements associated with a first RAT whether or not the UE receives an indication not to enter a DC mode (e.g., an indication that a DC silence mode is active or inactive) , the UE may perform a handover or redirection from the second RAT to the first RAT, which may improve spectral efficiency, improve bandwidth, and/or conserve computing, network, and/or communication resources for communications with a base station of the network.

As indicated above, Fig. 4 is provided as an example. Other examples may differ from what is described with regard to Fig. 4.

Fig. 5 is a diagram illustrating an example 500 associated with performance of secondary cell group adding procedures or handover or redirection procedures, in accordance with various aspects of the present disclosure. A UE (e.g., UE 120) of Fig. 5 may communicate with a base station (e.g., base station 110) . The UE and the base station may be part of a wireless network (e.g., wireless network 100) . In some aspects, the UE and the base station may perform one or more procedures associated with a DC mode, using a first RAT and the second RAT, and/or a handover or redirection from the second RAT to the first RAT. In some aspects, the first RAT may include a 5G NR RAT. In some aspects, the second RAT may include an E-UTRA RAT.

As shown by reference number 505, the UE may access a second RAT cell (e.g., an LTE cell) of a network. As shown by reference number 510, the UE may receive a first RAT measurement configuration from the network (e.g., an LTE-based network) .

As shown by reference number 515, the UE may perform a layer 2 measurement process for the first RAT and send a measurement report if a B1 event (e.g., receipt of a layer 2 measurement report object and/or a request to report layer 2 measurements) is triggered. As shown by reference number 520, the UE may receive a first RAT access command from the network. The first RAT access command may include an SCG adding command or a handover or redirection command.

As shown by reference number 525, if the first RAT access command indicates that the UE is to perform a handover or redirection (e.g., from the second RAT to the first RAT) , the UE may perform a handover or redirection process. In some aspects, the UE may perform the handover or redirection independently from (e.g., regardless of) an indication of a silence DC mode.

As shown by reference number 530, if the first RAT access command indicates that the UE is to perform SCG adding (e.g., NSA SCG adding) , the UE may ignore an SCG configuration and report an SCG failure to the network based at least in part on a determination that the silence DC mode is active. As shown by reference number 535, if the first RAT access command indicates that the UE is to perform SCG adding (e.g., NSA SCG adding) , the UE may perform an NSA SCG adding process based at least in part on a determination that the silence DC mode is inactive.

As indicated above, Fig. 5 is provided as an example. Other examples may differ from what is described with regard to Fig. 5.

Fig. 6 is a diagram illustrating an example process 600 performed, for example, by a UE, in accordance with various aspects of the present disclosure. Example process 600 is an example where the UE (e.g., UE 120) performs operations associated with performance of secondary cell group adding procedures or handover or redirection procedures.

As shown in Fig. 6, in some aspects, process 600 may include transmitting an indication of one or more layer 2 measurements associated with a first RAT (block 610) . For example, the UE (e.g., using transmission component 704, depicted in Fig. 7) may transmit an indication of one or more layer 2 measurements associated with a first RAT, as described above.

As further shown in Fig. 6, in some aspects, process 600 may include selectively performing, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the UE is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a SCG adding procedure, or the SCG adding procedure to add the SCG via the first RAT (block 620) . For example, the UE (e.g., using access component 708 and/or transmission component 704, depicted in Fig. 7) may selectively perform, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the UE is connected, one or more of: a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a SCG adding procedure, or the SCG adding procedure to add the SCG via the first RAT, as described above.

Process 600 may include additional aspects, such as any single aspect or any combination of aspects described below and/or in connection with one or more other processes described elsewhere herein.

In a first aspect, process 600 includes receiving, via the second RAT, a configuration for performing measurement of the one or more layer 2 measurements associated with the first RAT.

In a second aspect, alone or in combination with the first aspect, process 600 includes receiving the indication to not enter the DC mode associated with the first RAT and the second RAT, and performing, after receiving the indication to not enter the DC mode, measurement of the one or more layer 2 measurements associated with the first RAT.

In a third aspect, alone or in combination with one or more of the first and second aspects, the access command associated with the first RAT comprises an indication to perform the SCG adding procedure, or an indication to perform the handover or the redirection from the second RAT to the first RAT.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, process 600 includes performing, independently from receiving or not receiving the indication to not enter the DC mode, the handover or redirection from the second RAT to the first RAT based at least in part on the access command associated with the first RAT comprising the indication to perform the handover or the redirection.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, process 600 includes performing, based at least in part on receiving the indication to not enter the DC mode, transmission of the indication of the failure of the SCG adding procedure.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, the indication of the failure of the SCG adding procedure includes an indication of a synchronization reconfiguration failure.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, process 600 includes performing, based at least in part on not receiving the indication to not enter the DC mode, the SCG adding procedure.

In an eighth aspect, alone or in combination with one or more of the first through seventh aspects, the first RAT comprises a 5G New Radio RAT, and the second RAT comprises an Evolved Universal Terrestrial Radio Access RAT.

Although Fig. 6 shows example blocks of process 600, in some aspects, process 600 may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in Fig. 6. Additionally, or alternatively, two or more of the blocks of process 600 may be performed in parallel.

Fig. 7 is a block diagram of an example apparatus 700 for wireless communication. The apparatus 700 may be a UE, or a UE may include the apparatus 700. In some aspects, the apparatus 700 includes a reception component 702 and a transmission component 704, which may be in communication with one another (for example, via one or more buses and/or one or more other components) . As shown, the apparatus 700 may communicate with another apparatus 706 (such as a UE, a base station, or another wireless communication device) using the reception component 702 and the transmission component 704. As further shown, the apparatus 700 may include one or more of an access component 708.

In some aspects, the apparatus 700 may be configured to perform one or more operations described herein in connection with Figs. 4 and 5. Additionally or alternatively, the apparatus 700 may be configured to perform one or more processes described herein, such as process 600 of Fig. 6, or a combination thereof. In some aspects, the apparatus 700 and/or one or more components shown in Fig. 7 may include one or more components of the UE described above in connection with Fig. 2. Additionally, or alternatively, one or more components shown in Fig. 7 may be implemented within one or more components described above in connection with Fig. 2. Additionally or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component 702 may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus 706. The reception component 702 may provide received communications to one or more other components of the apparatus 700. In some aspects, the reception component 702 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples) , and may provide the processed signals to the one or more other components of the apparatus 706. In some aspects, the reception component 702 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2.

The transmission component 704 may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus 706. In some aspects, one or more other components of the apparatus 706 may generate communications and may provide the generated communications to the transmission component 704 for transmission to the apparatus 706. In some aspects, the transmission component 704 may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples) , and may transmit the processed signals to the apparatus 706. In some aspects, the transmission component 704 may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2. In some aspects, the transmission component 704 may be co-located with the reception component 702 in a transceiver.

The transmission component 704 may transmit an indication of one or more layer 2 measurements associated with a first RAT. The access component 708 and/or the transmission component 704 may selectively perform, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a DC mode associated with the first RAT and a second RAT with which the UE is connected, one or more of a handover or redirection from the second RAT to the first RAT, transmission of an indication of a failure of a SCG adding procedure, or the SCG adding procedure to add the SCG via the first RAT. In some aspects, the access component 708 may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection with Fig. 2.

The reception component 702 may receive, via the second RAT, a configuration for performing measurement of the one or more layer 2 measurements associated with the first RAT.

The reception component 702 may receive the indication to not enter the DC mode associated with the first RAT and the second RAT.

The reception component 702 may perform, after receiving the indication to not enter the DC mode, measurement of the one or more layer 2 measurements associated with the first RAT.

The access component 708 may perform, independently from receiving or not receiving the indication to not enter the DC mode, the handover or redirection from the second RAT to the first RAT based at least in part on the access command associated with the first RAT comprising the indication to perform the handover or the redirection.

The transmission component 704 may perform, based at least in part on receiving the indication to not enter the DC mode, transmission of the indication of the failure of the SCG adding procedure.

The access component 708 may perform, based at least in part on not receiving the indication to not enter the DC mode, the SCG adding procedure.

The number and arrangement of components shown in Fig. 7 are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown in Fig. 7. Furthermore, two or more components shown in Fig. 7 may be implemented within a single component, or a single component shown in Fig. 7 may be implemented as multiple, distributed components. Additionally or alternatively, a set of (one or more) components shown in Fig. 7 may perform one or more functions described as being performed by another set of components shown in Fig. 7.

The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the aspects.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code-it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.

As used herein, satisfying a threshold may, depending on the context, refer to a value being greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, and/or the like.

Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various aspects includes each dependent claim in combination with every other claim in the claim set. A phrase referring to “at least one of” a list of items refers to any combination of those items, including single members. As an example, “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .

No element, act, or instruction used herein should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more. ” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more. ” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, and/or the like) , and may be used interchangeably with “one or more. ” Where only one item is intended, the phrase “only one” or similar language is used. Also, as used herein, the terms “has, ” “have, ” “having, ” and/or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and/or, ” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of” ) .

Claims

A method of wireless communication performed by a user equipment (UE) , comprising:

transmitting an indication of one or more layer 2 measurements associated with a first radio access technology (RAT) ; and

selectively performing, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a dual connectivity (DC) mode associated with the first RAT and a second RAT with which the UE is connected, one or more of:

a handover or redirection from the second RAT to the first RAT,

transmission of an indication of a failure of a secondary cell group (SCG) adding procedure, or

the SCG adding procedure to add the SCG via the first RAT.
The method of claim 1, further comprising:

receiving, via the second RAT, a configuration for performing measurement of the one or more layer 2 measurements associated with the first RAT.
The method of claim 1, further comprising:

receiving the indication to not enter the DC mode associated with the first RAT and the second RAT; and

performing, after receiving the indication to not enter the DC mode, measurement of the one or more layer 2 measurements associated with the first RAT.
The method of claim 1, wherein the access command associated with the first RAT comprises:

an indication to perform the SCG adding procedure, or

an indication to perform the handover or the redirection from the second RAT to the first RAT.
The method of claim 4, further comprising:

performing, independently from receiving or not receiving the indication to not enter the DC mode, the handover or redirection from the second RAT to the first RAT based at least in part on the access command associated with the first RAT comprising the indication to perform the handover or the redirection.
The method of claim 4, further comprising:

performing, based at least in part on receiving the indication to not enter the DC mode, transmission of the indication of the failure of the SCG adding procedure.
The method of claim 6, wherein the indication of the failure of the SCG adding procedure includes an indication of a synchronization reconfiguration failure.
The method of claim 4, further comprising:

performing, based at least in part on not receiving the indication to not enter the DC mode, the SCG adding procedure.
The method of claim 1, wherein the first RAT comprises a 5G New Radio RAT; and

wherein the second RAT comprises an Evolved Universal Terrestrial Radio Access RAT.
A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors operatively coupled to the memory, the memory and the one or more processors configured to:

transmit an indication of one or more layer 2 measurements associated with a first radio access technology (RAT) ; and

selectively perform, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a dual connectivity (DC) mode associated with the first RAT and a second RAT with which the UE is connected, one or more of:

a handover or redirection from the second RAT to the first RAT,

transmission of an indication of a failure of a secondary cell group (SCG) adding procedure, or

the SCG adding procedure to add the SCG via the first RAT.
A non-transitory computer-readable medium storing a set of instructions for wireless communication, the set of instructions comprising:

one or more instructions that, when executed by one or more processors of a user equipment (UE) , cause the UE to:

transmit an indication of one or more layer 2 measurements associated with a first radio access technology (RAT) ; and

selectively perform, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a dual connectivity (DC) mode associated with the first RAT and a second RAT with which the UE is connected, one or more of:

a handover or redirection from the second RAT to the first RAT,

transmission of an indication of a failure of a secondary cell group (SCG) adding procedure, or

the SCG adding procedure to add the SCG via the first RAT.
An apparatus for wireless communication, comprising:

means for transmitting an indication of one or more layer 2 measurements associated with a first radio access technology (RAT) ; and

means for selectively performing, based at least in part on reception of one or more of an access command associated with the first RAT or an indication to not enter a dual connectivity (DC) mode associated with the first RAT and a second RAT with which the apparatus is connected, one or more of:

a handover or redirection from the second RAT to the first RAT,

transmission of an indication of a failure of a secondary cell group (SCG) adding procedure, or

the SCG adding procedure to add the SCG via the first RAT.