WO2018058527A1

WO2018058527A1 - Autonomous uplink benefit identification

Info

Publication number: WO2018058527A1
Application number: PCT/CN2016/101083
Authority: WO
Inventors: Peng Cheng; Vinay Chande; Arumugam Chendamarai Kannan; Chirag Patel
Original assignee: Qualcomm Inc
Current assignee: Qualcomm Inc
Priority date: 2016-09-30
Filing date: 2016-09-30
Publication date: 2018-04-05
Anticipated expiration: 2019-03-30

Abstract

Methods, systems, and devices for wireless communication are described. A base station within a wireless system may determine a measurement scheme or uplink mode and then transmit an indication of the scheme or uplink mode to an associated user equipment (UE). The base station may, for example, identify a set of hidden nodes for the UE and configure the UE for autonomous or grant-based uplink transmissions accordingly. The UE may identify a signal strength of neighboring nodes, which the UE may communicated to the base station for identification of hidden nodes. In some examples, the UE may be configured with an autonomous uplink, which may support unscheduled uplink communications, when a base station determines that operating in the autonomous uplink mode would provide a benefit for the UE—e.g., a benefit for UE operation in view of hidden nodes with which the UE may contend.

Description

AUTONOMOUS UPLINK BENEFIT IDENTIFICATION

BACKGROUND

The following relates generally to wireless communication and more specifically to autonomous uplink benefit identification.

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 code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, and orthogonal frequency division multiple access (OFDMA) systems, (e.g., a Long Term Evolution (LTE) system) . A wireless multiple-access communications system may include a number of base stations, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

In some wireless systems, a device operable for scheduled wireless communication may operate in an unscheduled, contention based wireless system. In a contention based wireless system, multiple nodes may attempt to access a medium by sending messages to other nodes. Once a node wins access to the medium, the node may communicate with the other nodes over the medium for a given time. In some instances, a neighboring node, such as a UE, may already be in communication with another node, such as a base station, and other UEs may be unable to detect a response from the base station indicating that the medium is occupied. The neighboring node may be referred to as a hidden node. Communications involving hidden nodes may result in interference and other communication issues with other devices in the system.

SUMMARY

The described techniques relate to improved methods, systems, devices, or apparatuses that support autonomous uplink benefit identification. Generally, the described techniques may provide for identifying a node capable of operating in an autonomous uplink mode. Once a node is identified, it may be configured to operate in an autonomous uplink mode if, for example, operating in the autonomous uplink mode would be a benefit.

For example, a base station may determine a number of hidden nodes associated with a given node (e.g., a user equipment (UE) ) . Based on the number of hidden nodes, the base station may configure the UE to operate in an autonomous uplink mode. To determine whether neighbor nodes are hidden nodes, a UE may determine the signal strength of neighboring nodes by measuring signals from the neighboring nodes according to different measurement schemes. Based on the measurements, the UE may transmit an indication to the base station that includes information (e.g., signal strength) related to the neighboring nodes or may transmit a set of nodes whose received signal strength is above a threshold.

A base station may also measure signal strength of neighboring nodes and generate a difference between the set of nodes measured by the base station and the set of nodes from the UE. If a base station determines that a number of hidden nodes for an associated UE is below a certain threshold, the base station may select an autonomous uplink mode for the UE, and transmit an indication of the autonomous uplink mode to the UE. After receiving the indication, the UE may transmit an uplink message (e.g., in an unlicensed spectrum) to the base station according to the autonomous uplink mode.

A method of wireless communication is described. The method may include identifying a set of hidden nodes for a UE, selecting an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions, and transmitting an indication of the autonomous uplink mode to the UE.

An apparatus for wireless communication is described. The apparatus may include means for identifying a set of hidden nodes for a UE, means for selecting an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions, and means for transmitting an indication of the autonomous uplink mode to the UE.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to identify a set of hidden nodes for a UE, select an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions, and transmit an indication of the autonomous uplink mode to the UE.

A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a set of hidden nodes for a UE, select an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions, and transmit an indication of the autonomous uplink mode to the UE.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, identifying the set of hidden nodes for the UE comprises: determining that a number of hidden nodes in the set may be below a threshold. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, identifying the set of hidden nodes for the UE comprises: determining that a signal strength for each hidden node in the set may be below a threshold.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for receiving information associated with a hidden node of the set from the UE, wherein the autonomous uplink mode may be selected based at least in part on the information associated with the hidden node. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the information associated with the hidden node comprises a list of information associated with hidden nodes of the set.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the information associated with the hidden node comprises an indication of a signal strength of the hidden node at the UE.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, transmitting the indication of the autonomous uplink mode comprises: transmitting the indication of the autonomous uplink mode in a radio resource control (RRC) message.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for measuring a channel metric for the UE. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for determining that the channel metric may be above a threshold. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for transmitting an indication to operate in a grant-based mode to the UE, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for generating a channel metric histogram for the UE, wherein the channel metric histogram may be generated based at least in part on uplink feedback from the UE.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the channel metric comprises a channel quality indicator (CQI) backoff, a contention window metric, or a combination thereof.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for transmitting a measurement scheme to the UE. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for receiving information associated with a hidden node of the set from the UE, wherein the information associated with the hidden node comprises a signal strength indication that may be based at least in part on the measurement scheme. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the set of hidden nodes may be identified based at least in part on the information associated with the hidden node received from the UE.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the measurement scheme comprises an indication to measure a neighboring node and the neighboring node comprises at least one of a UE, a base station, an access point, or a station, or any combination thereof.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the measurement scheme comprises a periodic report type and a report interval or a triggered report type.

Another method of wireless communication is described. The method may include measuring a signal from a neighboring node in an unlicensed radio frequency spectrum band, transmitting information associated with the measurement to a base station, receiving an RRC message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band, and transmitting an uplink message to the base station according to the autonomous uplink mode.

Another apparatus for wireless communication is described. The apparatus may include means for measuring a signal from a neighboring node in an unlicensed radio frequency spectrum band, means for transmitting information associated with the measurement to a base station, means for receiving an RRC message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band, and means for transmitting an uplink message to the base station according to the autonomous uplink mode.

Another apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to measure a signal from a neighboring node in an unlicensed radio frequency spectrum band, transmit information associated with the measurement to a base station, receive an RRC message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band, and transmit an uplink message to the base station according to the autonomous uplink mode.

A non-transitory computer readable medium for wireless communication is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to measure a signal from a neighboring node in an unlicensed radio frequency spectrum band, transmit information associated with the measurement to a base station, receive an RRC message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band, and transmit an uplink message to the base station according to the autonomous uplink mode.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for determining that a strength of the signal from the neighboring node exceeds a threshold, wherein the information associated with the measurement may be transmitted based at least in part on the determination that the strength of the signal from the neighboring node exceeds the threshold.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the information associated with the measurement comprises an element in a list of neighboring nodes having a signal strength that exceeds a threshold, and transmitting the information comprises: transmitting a message with the list of neighboring nodes.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for receiving, based at least in part on a channel metric, an indication from the base station to operate in a grant-based mode, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant from the base station.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the channel metric comprises a CQI backoff, a contention window metric, or a combination thereof.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for receiving, from the base station, a message that comprises a request for a measurement capability. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for transmitting an additional uplink message that indicates the measurement capability in response to the request, wherein the measurement capability comprises a wireless local area network (WLAN) signal strength capability.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the measurement capability comprises a measurement parameter configuration comprising a measurement frequency, a measurement dwell time, a signal strength threshold, or any combination thereof.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for periodically transmitting a result associated with the measurement to the base station.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for receiving, from the base station, a request to measure the signal of the neighboring node. Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for transmitting a measurement result based at least on the received request.

Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may further include processes, features, means, or instructions for receiving a measurement scheme from the base station, wherein measuring the signal from the neighboring node may be based at least in part on the measurement scheme.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the neighboring node comprises at least one of a UE, a neighbor base station, an access point, or a station.

In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the neighboring node comprises a hidden node in a set of hidden nodes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communication that supports autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIG. 2A illustrates an example of a grant-based communication accordance with one or more aspects of the present disclosure.

FIG. 2B illustrates an example of an autonomous uplink communication in accordance with one or more aspects of the present disclosure.

FIG. 3 illustrates an example of a wireless communication system including a potential hidden node that supports autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIGs. 4A and 4B illustrate examples of a measurement configuration that supports autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIGs. 6 through 8 show block diagrams of a device or devices that support autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIG. 9 illustrates a block diagram of a system including a base station that supports autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIGs. 10 through 12 show block diagrams of a device or devices that support autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIG. 13 illustrates a block diagram of a system including a user equipment (UE) that supports autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

FIGs. 14 and 15 illustrate methods for autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure.

DETAILED DESCRIPTION

A user equipment (UE) may benefit from operating in an autonomous (i.e., unscheduled) uplink mode or the UE may benefit from operating in a grant-based (i.e., scheduled) uplink mode, depending on various factors within a system. In an autonomous uplink mode, the UE , may make unscheduled uplink transmissions in an unlicensed radio frequency spectrum band, while in a grant-based mode the UE may make uplink transmissions using resources assigned by (i.e., scheduled) with a grant from the base station. Whether a UE is likely to benefit from unscheduled uplink transmissions may be a function of the number of neighboring nodes, including hidden nodes, with which the UE is contending for access to the unlicensed radio frequency spectrum band. A base station may thus select an autonomous uplink mode for the UE based on conditions determined or identified by the base station when doing so is likely to benefit the UE.

By way of example, grant-based deployments may sometimes provide for more efficient resource utilization compared to distributed (e.g. unscheduled or non-scheduled) wireless communication systems. But when a scheduled uplink scheme coexists with a non-scheduled uplink scheme, the former may suffer a disadvantage in channel access. This disadvantage may be a result of various scenarios or factors, including the following three factors (referred to as a triple contention scenario) : first, a base station a, operating in a scheduled uplink system, may perform a listen-before-talk (LBT) procedure before sending a grant, which may result in contention with other Wi-Fi access points (APs) or user equipment (UEs) ； second, the uplink scheduling or UE selection may cause another internal contention within the base station； third, the scheduled UE may also individually perform LBT.

Due at least in part to these three factors, scheduled or grant-based implementations (e.g., within a MulteFire systems) coexisting with unscheduled or autonomous implementations may affect uplink data rates compared to those achieved with standalone unscheduled or autonomous wireless communication systems (e.g. WiFi systems or certain MulteFire deployments) . The capability to switch between scheduled and unscheduled modes of operation may therefore allow a UE to benefit from a particular uplink scheme that is likely to confer the most benefit.

A UE may realize more efficient medium access by operating in an autonomous uplink mode. In an autonomous uplink mode, the UE may communicate with a base station without receiving an uplink grant indicating that the UE has been granted access to a medium. Such a mode may also be referred to as a grant-less mode. Compared to a grant-based uplink mode, operating in an autonomous uplink mode may provide more efficient communication because of a relative reduction overhead (e.g., control signaling) and complexity. However, in some scenarios, issues may arise when communicating according to autonomous uplink mode. For instance, a hidden node (i.e., a node that is unknown to the UE) may exist when a UE is communicating with a base station in an unscheduled system, which may result in high interference at the base station communicating with multiple nodes.

To reduce complexity and overhead, while addressing the hidden node problem, a number of hidden nodes associated with a given UE may be determined. Based on the number of hidden nodes, a base station may configure the UE to operate in an autonomous uplink mode or not. For example, if the number of hidden nodes associated with the given UE is less than a hidden node threshold, the base station may determine that operating in an autonomous uplink mode may be beneficial and may also result in increased uplink data rates.

In determining the number of hidden nodes for a given UE, the UE may identify the signal strength of neighboring nodes by measuring signals from the neighboring nodes according to different measurement schemes. The measurement scheme may vary depending on the neighboring node type and addition information and may be transmitted from the base station to the UE to indicate the types of measurements to be made. Based on the measurements, the UE may transmit an indication to the base station that includes information (e.g., signal strength) related to the neighboring nodes or may transmit a set of nodes whose received signal strength is above a threshold. The base station may also measure signal strength of nodes that are neighbors to the base station. By generating a difference between the set of nodes measured by the base station and the set of nodes from the UE, a base station may determine whether to operate according to an autonomous uplink mode. Once determined, the base station may transmit an indication to operate according to the autonomous uplink mode (e.g., in a radio resource control (RRC) message) and the UE may then be configured to transmit an uplink message (e.g., in an unlicensed spectrum) to the base station according to the autonomous uplink mode.

Aspects of the disclosure introduced above are further described below with reference to a wireless communication system. Examples of autonomous uplink benefit identification are then illustrated with reference to various relationships between uplink and downlink transmission timing and effects of neighboring nodes on a UE. These and other features are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to autonomous uplink benefit identification.

FIG. 1 illustrates an example of a wireless communications system 100 in accordance with various aspects of the present disclosure. The wireless communications system 100 includes base stations 105, UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) /LTE-Advanced (LTE-A) network. Additionally or alternatively, wireless communications system 100 may be an example of a wireless local area network (WLAN) (e.g., a Wi-Fi network) or a MulteFire network.

The wireless network 100 may include an access point (AP) and multiple associated UEs 115, which may represent devices such as wireless stations, mobile stations, personal digital assistant (PDAs) , other handheld devices, netbooks, notebook computers, tablet computers, laptops, display devices (e.g., TVs, computer monitors, etc. ) , printers, etc. A UE 115 may also be referred to as a mobile station, a subscriber station, a remote unit, a wireless device, an access terminal (AT) , a handset, a user agent, a client, cellular phone, a wireless modem, a handheld device, a personal computer, a tablet, a personal electronic device, a machine type communication (MTC) device, or the like.

When wireless communications system 100 is configured as a MulteFire network, the AP may be configured as a MulteFire eNB or base station. For example, wireless communications system 100 may include aspects of an LTE/LTE-Anetwork, a Wi-Fi network, a MulteFire network, a neutral host small cell network, or the like, operating with overlapping coverage areas. A MulteFire network may include access points (APs) and/or base stations 105 communicating with UEs 115 in an unlicensed radio frequency spectrum band, e.g., without a licensed frequency anchor carrier. For example, the MulteFire network may operate without an anchor carrier in the licensed spectrum. Wireless communications system 100 may support autonomous uplink benefit identification techniques which may, e.g., increase the efficiency of MulteFire communications within system 100.

Base stations 105 may wirelessly communicate with UEs 115 via one or more base station antennas. Each base station 105 may provide communication coverage for a respective geographic coverage area 110. Communication links 125 shown in wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions, from a base station 105 to a UE 115. UEs 115 may be dispersed throughout the wireless communications system 100, and each UE 115 may be stationary or mobile. Although a base station 105 may generally refer to aspects of wireless wide area networks (WWANs) and an AP may generally refer to aspects of WLANs, base station and AP may be used interchangeably. As discussed below, a base station 105 may identify conditions (e.g., number of hidden nodes) of a UE 115, and the network 130, via base station 105, may configured the UE 115 accordingly.

Base stations 105 may communicate with the core network 130 and with one another. For example, base stations 105 may interface with the core network 130 through backhaul links 132 (e.g, S1, etc. ) . Base stations 105 may communicate with one another over backhaul links 134 (e.g, X2, etc. ) either directly or indirectly (e.g, through core network 130) . Base stations 105 may perform radio configuration and scheduling for communication with UEs 115, or may operate under the control of a base station controller (not shown) . In some examples, base stations 105 may be macro cells, small cells, hot spots, or the like. Base stations 105 may also be referred to as eNodeBs (eNBs) 105. Base stations 105 may also be MulteFire base stations 105, which may have limited or non-ideal backhaul links 134 with other base stations 105.

As mentioned, UE 115s, APs, and base stations 105 may operate in a shared or unlicensed radio frequency spectrum band. These devices may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. A CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, the device may infer that a change in a received signal strength indication (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter.

When a receiver receives a packet from a transmitter, the receiver can advantageously assess the RSSI from that packet. In general, if channel conditions become better, then the RSSI typically increases, whereas if the channel conditions become worse, the RSSI typically decreases. In some cases, the RSSI of the packet can be reported by the hardware in the status portion of the transmitter’s receive descriptor. A CCA may also include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence. The frequency and timing of CCA may affect the frequency with which a UE 115 is able to access a shared or unlicensed channel. As discussed above, if both a UE 115 and an associated base station 105 are performing CCA procedures, the frequency with which the UE 115 successful gains access to the shared or unlicensed channel may decrease because other devices may have less complex LBT procedures and may more readily win access to the medium.

UEs 115 and base stations 105 may employ a hybrid automatic repeat request (HARQ) feedback mechanism, which may be a method of ensuring that data is received correctly over a wireless communication link 125. 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 media access control (MAC) layer in poor radio conditions (e.g., signal-to-noise conditions) . In Incremental Redundancy HARQ, incorrectly received data may be stored in a buffer and combined with subsequent transmissions to improve the overall likelihood of successfully decoding the data. In some cases, redundancy bits are added to each message prior to transmission. This may be useful in poor conditions. In other cases, redundancy bits are not added to each transmission, but are retransmitted after the transmitter of the original message receives a negative acknowledgement (NACK) indicating a failed attempt to decode the information. The chain of transmission, response and retransmission may be referred to as a HARQ process. In some cases, a limited number of HARQ processes may be used for a given communication link 125.

In some cases, wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system 100 may employ LTE License Assisted Access (LTE-LAA) or LTE Unlicensed (LTE U) radio access technology in an unlicensed band such as the 5GHz Industrial, Scientific, and Medical (ISM) band. (The ISM band may also be used for other communications, such as MulteFire or Wi-Fi. ) When operating in unlicensed radio frequency spectrum bands, wireless devices such as base stations 105 and UEs 115 may employ LBT procedures, such as a CCA, to ensure the channel is clear before transmitting data. In some cases, operations in unlicensed bands may be based on a carrier aggregation (CA) configuration in conjunction with component carriers (CCs) operating in a licensed band. Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, or both. Duplexing in unlicensed spectrum may be based on frequency division duplexing (FDD) , time division duplexing (TDD) or a combination of both.

Bidirectional communications may use FDD (e.g., using paired spectrum resources) or TDD operation (e.g., using unpaired spectrum resources) . Frame structures for FDD (e.g., frame structure type 1) and TDD (e.g., frame structure type 2) may be defined. For TDD frame structures, each subframe may carry uplink or downlink traffic, and special subframes may be used to switch between downlink and uplink transmission. Allocation of uplink and downlink subframes within radio frames may be symmetric or asymmetric and may be statically determined or may be reconfigured semi-statically. Special subframes may carry downlink or uplink traffic and may include a Guard Period (GP) between downlink and uplink traffic. Switching from uplink to downlink traffic may be achieved by setting a timing advance at the UE 115 without the use of special subframes or a guard period. UL-DL configurations with switch-point periodicity equal to the frame period (e.g., 10 ms) or half of the frame period (e.g., 5 ms) may also be supported.

For example, TDD frames may include one or more special frames, and the period between special frames may determine the TDD DL-to-UL switch-point periodicity for the frame. Use of TDD offers flexible deployments without requiring paired UL-DL spectrum resources. In some TDD network deployments, interference may be caused between uplink and downlink communications (e.g., interference between uplink and downlink communication from different base stations, interference between uplink and downlink communications from base stations and UEs, etc. ) . For example, where different base stations 105 serve different UEs 115 within overlapping coverage areas according to different TDD UL-DL configurations, a UE 115 attempting to receive and decode a downlink transmission from a serving base station 105 may experience interference from uplink transmissions from other, proximately located UEs 115.

In some cases, a UE 115 (or an AP) may be detectable by a central AP, but not by other UEs 115 in the coverage area 110 of the central AP. For example, one UE 115 may be at one end of the coverage area 110 of the central AP while another UE 115 may be at the other end (e.g., a hidden node) . Thus, both UEs 115 may communicate with the AP, but may not receive the transmissions of the other. This may result in colliding transmissions for the two UEs 115 in a contention based environment (e.g., carrier sense multiple access with collision avoidance (CSMA/CA) ) because the UEs 115 may not refrain from transmitting on top of each other. A UE 115 whose transmissions are not identifiable, but that is within the same coverage area 110 may be known as a hidden node. In some examples described herein, a UE 115 and AP of interest may be referred to as a victim UE or victim AP in the presence of a potentially interfering neighbor UE or AP (e.g., a hidden node) , which may be further referred to as an aggressor UE or aggressor AP.

In some cases, intra-cell UE ambiguity and transmission collisions may result in decreased system performance (e.g. due to timing synchronization issues) . Intra-cell UE ambiguity and/or transmission collisions may arise in scenarios where two or more UEs are unable to detect each other (e.g. the hidden node issue described above) . In some cases, a grant may be used by a base station 105 to allocate resources to UEs 115. In autonomous uplink (e.g., grant-less uplink) , the base station may detect the presence of the PUSCH and identify a UE through a demodulated reference signal (DMRS) or scheduling request (SR) . After one autonomous uplink UE successfully contends the medium, the base station may detect its PUSCH. However, since other intra-cell UEs may not detect the DMRS and SR from this UE, another intra-cell UE (e.g, an aggressor) may also successfully contend the medium. As a result, the base station may have a misaligned TDD configuration and frame start-timing, which may result in a collision between the transmissions from the two UEs as further described below.

As discussed above, UEs 115 operating in a shared radio frequency spectrum band may be unable to readily determine a frame structure used in the system without some indication of timing and the like. Time intervals in system 100 may be expressed in multiples of a basic time unit (e.g., the sampling period, Ts＝ 1/30, 720,000 seconds) . Time resources may be organized according to radio frames of length of 10ms (Tf ＝ 307200Ts) , which may be identified by a system frame number (SFN) ranging from 0 to 1023.

Each frame may include ten 1ms subframes numbered from 0 to 9； other frame structures may also be employed, as discussed below. A subframe may be further divided into two . 5ms slots, each of which contains 6 or 7 modulation symbol periods (depending on the length of the cyclic prefix prepended to each symbol) . A resource element may consist of one symbol period and one subcarrier (a15 KHz frequency range) . A resource block may contain 12 consecutive subcarriers in the frequency domain and, for a normal cyclic prefix in each orthogonal frequency division multiplexing (OFDM) symbol, 7 consecutive OFDM symbols in the time domain (1 slot) , or 84 resource elements.

Excluding the cyclic prefix, each symbol may contain 2048 sample periods. In some cases the subframe may be the smallest scheduling unit, also known as a transmission time interval. In other cases, a TTI may be shorter than a subframe or may be dynamically selected (e.g., in short TTI bursts or in selected component carriers using short TTIs) . A subframe may have different structures depending on the type and direction of information to be transmitted. A subframe type may be an uplink subframe, a downlink subframe, or a special (S) subframe. Special subframes may facilitate a switch from downlink to uplink transmission. Further the structure of a subframe may vary in terms of length.

Other frame structures may also be employed in wireless communications system 100. In some cases, wireless communications system 100 may be organized by transmission opportunities (TxOPs) , which may be organized according to the frame structure described above and which a may be separated by periods of time during which the wireless medium may be unavailable for devices (e.g., UEs 115 or base stations 105) within wireless communications system 100.

A UE 115 may benefit from operating in an autonomous uplink mode or the UE 115 may benefit from operating in a grant-based uplink mode, depending on various factors within a system. Whether a UE 115 is likely to benefit from unscheduled uplink transmissions may be a function of the number of neighboring nodes, including hidden nodes, with which the UE 115 is contending for access to the unlicensed radio frequency spectrum band. A base station 105 may thus select an autonomous uplink mode for the UE based on conditions determined or identified by the base station when doing so is likely to benefit the UE.

FIG. 2A illustrates an example of a grant-based communication 201 in accordance with one or more aspects of the present disclosure. Grant-based communication system 201 may include UE 115-c and base station 105-b, which may be examples of or may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-2. In FIG. 2A, base station 105-b is in communication with UE 115-c.In the grant-based communication system 201, base station 105-b may initiate a CCA procedure 205 to determine whether the channel is available for communication. Once it is determined that the channel is available, base station 105-b may then transmit a preamble 215, which may include a reservation signal (e.g., a clear to send (CTS) message) to reserve the medium for UL transmission. For example, preamble 215 may indicate to UE 115-c that the medium is reserved for a given TxOP. In the example depicted in FIG. 2A, the TxOP includes a special subframe followed by 8 ms (i.e., 9 consecutive 1 ms subframes) , but other durations may also be employed. Based on the preamble 215, UE 115-c may also initiate its own CCA procedure at 220, and may transmit a busy signal 225 indicating that the channel is reserved. This process may occur during special subframe 210.

FIG. 2B illustrates an example of an autonomous uplink mode communication 202 in accordance with one or more aspects of the present disclosure. Autonomous uplink mode communication 202 may include UE 115-d and base station 105-c, which may be examples of or may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-2. As opposed to the grant-based communication system 201, in autonomous uplink mode communication 202, base station 105-c may not need to initiate a CCA or transmit a preamble. As a result, there may be no need for allocating a subframe as a special subframe, as no preamble detection and decoding is performed by UE 115-d. This allows an additional subframe to be allocated for uplink transmission, as shown. In the autonomous uplink mode communication 202, UE 115-d may initiate a CCA procedure 220 to determine whether the channel is available for communication. If it is determined that the channel is available, the UE 115-d may transmit a busy signal 225 indicating that the channel is reserved for communication. Based on CCA procedure 220, UE 115-d may initiate an UL transmission without requiring base station 105-c to initiate its own CCA or transmit a preamble indicating that the UE 115-d has been granted access to the channel.

Operating in an autonomous uplink mode may result in strong interference experienced at a base station in a hidden node scenario, as discussed below. Therefore, in some examples, determining whether to operate in an autonomous uplink mode may lead to more efficient communication between a base station and a UE.

FIG. 3 illustrates an example of a wireless communication system 300 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. Wireless communication system 300 may include a base station 105-c, a UE 115-c, and a UE 115-d, which may be examples of the corresponding devices described with reference to FIGs. 1 and 2. As shown, base station 105-c is capable of communicating with UE 115-c over communication link 305. Base station 105-c is also configured to communicate with UE 115-d over communication link 310.

When operating in a grant-based mode, UE 115-d, a neighboring node with respect to UE 115-c, will remain silent when UE 115-c is communicating with base station 105-c. This occurs when neighbor UE 115-d is within a preamble detection range 320 of base station 105-c, and is therefore capable of hearing a preamble message transmitted by base station 105-c to UE 115-c. For example, UE 115-c and UE 115-d may each contend for access to a medium of wireless communication system 300 by sending separate request to the base station 105-c. The requests may contain information related to the UE 115-d (e.g., UE ID) or the data to be communicated (e.g., the data size or transmission duration based on a given MCS) . The base station 105-c may grant access to UE 115-c and may send a preamble transmission and an UL grant to the UE 115-c granting access to the medium. Neighbor UE 115-d may hear the preamble, determine that UE 115-c has gained access to the medium, and defer transmitting during a TxOP duration (e.g., which may be obtained by decoding the preamble) allocated to UE 115-c. Thus, when the UE 115-c transmits a message over 305 to base station 105-c, neighbor UE 115-d may remain silent and elect not to transmit over 310.

If wireless communication system 300 is operating in an autonomous uplink mode (e.g., a grant-less mode) , communication issues may arise when a neighbor UE 115-d is a hidden node. For example, a base station 105-c may be located closer to neighbor UE 115-d than UE 115-c and neighbor UE 115-d may be outside of an energy detection range 315 associated with UE 115-c. When operating in an autonomous uplink mode, UE 115-c may initiate its UL transmission over communication link 305 without receiving a grant from the base station 105-c. However, as a result of being located outside of the energy detection range 315, neighbor UE 115-d may not be able to detect the transmission over communication link 305 and may therefore initiate its own UL transmission over communication link 310. Due to the reception of two messages (one from each of UEs 115-c and 115-d, over the same resources at approximately the same time) at base station 105-c, strong interference may occur at base station 105-c. Thus, to more efficiently communicate when operating according to an autonomous uplink mode, a base station 105-c may determine whether a number of hidden nodes are associated with a given UE 115. Based on the number of hidden nodes, a UE 115 and a base station 105-c may be configured to communicate according to an autonomous uplink mode.

n order to determine whether neighboring nodes are hidden nodes, UE 115-c may identify or measure the signal strength of neighboring nodes (e.g., UE 115-d) . Depending on the type of node, measurements may be taken in different ways. For example, measurements may be made through Wi-Fi beacons or DRS for a neighbor node that is an AP or a base station, respectively. Measurements may be made through STA ACK/NACK received signal strength indicator (RSSI) measurements or LTE-Direct (LTE-D) discovery signals for a neighbor node that is a STA or an UE 115, respectively. Measurements may also be made according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11k standard measurements for a STA. Other measurement may be considered without departing from the scope of the present disclosure.

Further, a UE 115-c may measure neighboring nodes based on a measurement scheme. The measurement scheme may be transmitted to the UE 115-c (e.g., from base station 105-c) and may indicate to the UE 115-c what types of neighboring nodes should be measured. The measurement scheme may also include information relating to the report type (e.g., triggered or periodic) when reporting the measurements back to the base station 105-c. For example, any combination of measurements made for a neighboring AP, STA, UE 115, or base station, may be indicated in the measurement scheme. In some examples, UE 115-c may identify or measure only one type of neighboring node and in other cases, the UE may identify or measure several or all types of neighboring nodes. The measurement scheme may be indicated to the UE 115-c through RRC signaling, for example.

In some examples, base station 105-c may request a measurement capability of UE 115-c using a capability check request. For instance, base station 105-c may transmit a capability check request to determine whether UE 115-c is capable of measuring one or more measurement parameters (e.g., frequency, scan type (e.g., active/passive) , scan dwell time, or RSSI threshold) . The capability check request may also be used to determine whether UE 115-c is capable of measuring Wi-Fi signals (e.g., signals from Wi-Fi AP or signals from Wi-Fi STA) . In some instances, a reporting type, such as whether UE 115-c should report measurements periodically or based on a trigger, may also be included in the capability check request.

Based on the identified or measured signal strength for neighboring nodes, UE 115-c may determine that a neighboring node (e.g., UE 115-d) is a hidden node. For example, the measured signal strength (s) may be compared to a threshold value (i.e., an energy detection (ED) threshold or a preamble detection (PD) threshold) . In some cases, measured RSSI between various devices may be used to indicate whether a neighbor node is a hidden node. For instance, because the location or configuration of a neighboring node may affect the measured signal strength, neighbor UE 115-d may not hear UE 115-c when UE 115-c initiates an UL transmission. In another example, UE 115-c may be capable of measuring a signal strength from a neighbor UE 115-d, but may not backoff in an autonomous uplink system (e.g., due to the measured signal strength being below a threshold) . In such cases, UE 115-c will initiate its own UL transmission.

In some examples, base station 105-c may determine to configure operations with UE 115-c according to an autonomous uplink mode. In such examples, UE 115-c may measure one or more nearby neighbors, such as UE 115-d. UE 115-c may then transmit a hidden node indication to base station 105-c. The hidden node indication may be based on, for example, the measured signal strength of one or more neighboring nodes, as discussed above. The hidden node indication may also include a set of nodes that may be potential hidden nodes with respect to UE 115-c.

After receiving the hidden node indication, the base station 105-c may also measure nearby neighboring nodes according to the measurement scheme. This measurement may include identifying signal strength from a neighboring node. Based on these measurements and the information contained in the hidden node indication, base station 105-c may identify a number of hidden nodes associated with UE 115-c. To do so, base station 105-c may generate a set difference between the set of neighboring nodes contained in the hidden node indication and a set of neighboring nodes determined by the base station 105-c. If, for example, a neighboring node is within the set of neighboring nodes measured by the base station, but is not within the set of neighboring nodes indicated by the hidden node indication, the neighboring node may be identified as a hidden node. Thus, using this technique, the base station 105-c may determine a number of hidden nodes associated with UE 115-c.

To determine whether to configure UE 115-c to operate in an autonomous uplink mode, the base station 105-c may determine the number of hidden nodes associated with UE 115-c, as discussed above. If the number of nodes is below a given threshold, the base station 105-c may select an autonomous uplink mode for communication with UE 115-c. In such cases, the base station 105-c may transmit an indication of the autonomous uplink mode to UE 115-c. This indication may be transmitted in a RRC message, for example. The UE 115-c may then configure itself to operate in the autonomous uplink mode and transmit and uplink message to the base station 105-c over an unlicensed spectrum according to the autonomous uplink mode.

In some examples, base station 105-c may determine to communicate with UE 115-c according to an autonomous uplink mode by using aided information such as a channel metric (e.g., Channel Quality Indicator (CQI) backoff, contention window size) or any other additional information. For example, base station 105-c may determine that a number of hidden nodes for UE 115-c is below a certain threshold by measuring a CQI backoff metric for UE 115-c. If the CQI backoff metric is below a certain threshold, base station 105-c may determine to communicate with UE 115-c in an autonomous uplink mode. Alternatively, base station 105-c may determine that the CQI backoff metric is above a certain threshold. In such cases, the base station 105-c may communicate with UE 115-c according to a grant based mode.

In some examples, base station 105-c may maintain a channel metric histogram over time for one or more UEs 115. For example, base station 105-c may maintain a CQI backoff histogram for UE 115-c. The CQI backoff histogram may be determined based at least in part on uplink ACK/NACK feedback from UE 115-c. Based on the CQI backoff histogram, the base station 105-c may configure UE 115-c to operate according to a grant based mode or in an autonomous uplink mode. In some examples, base station 105-c may semi-statically configure UE 115-c to operate in an autonomous uplink mode (e.g., through RRC configuration or reconfiguration) .

Neighbor Type	Signal to Measure
AP	Wi-Fi Beacon
Base Station	DRS
STA	STA ACK RSSI or 802.11k STA measurements
UE	LTE-D discovery signal

Table 1

Table 1 illustrates exemplary neighboring node types and associated signals to measure. In Table 1, depending on whether the neighbor is an AP, a base station, a STA, or a UE, different signals may be used to obtain measurements for the neighbor. For instance, if the neighboring node is an AP, the Wi-Fi beacon transmitted by the AP may be used to obtain measurements for signal strength. If the neighboring node is a base station, the DRS transmitted by the base station may be use to obtain measurements for signal strength.

The measurement schemes may be divided into 6 schemes. Scheme 1: measure base stations, APs, STAs, and UEs； Scheme 2: measure base stations, APs, and STAs； Scheme 3: measure base stations and APs； Scheme 4: measure base stations only； Scheme 5: measure base stations including aided information； and Scheme 6: measure aided information only. Any or all such measurement schemes may be configured through RRC signaling.

FIGs. 4A and 4B illustrate examples of a measurement configuration that supports autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure. In FIG. 4A, wireless communication system 401 includes a UE 115-e, a UE 115-f, and base station 105-d, which may be examples of or may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-3. In some examples, a UE 115-e may determine whether a neighbor UE 115-f is a hidden node. This may involve determining a RSSI associated with one or more devices in wireless communication system 401. For example, UE 115-e may measure the RSSI-b 410, which may include measuring a signal (e.g., a LTE-D signal or a STA ACK) from UE 115-f. The UE 115-e may then compare the measured RSSI-b 410 to a given ED threshold, which may depend upon the neighbor node type. For example, if the node is a UE in an LTE system, then the ED threshold may be equal to -72 dBm. In another example, if the node is a STA in a WiFi system, then the ED threshold may be equal to -62 dBm.

If the measured RSSI is below the ED threshold, UE 115-e may determine that neighbor UE 115-f will not backoff from communication. That is, neighbor UE 115-f may not hear UE 115-e when it initiates a UL transmission or UE 115-f may hear the transmission from UE 115-e but may determine that because the transmission energy is below a given threshold, the UE 115-f is able to transmit on top of the transmission from UE 115-e. In such cases, because neighbor UE 115-f will not backoff, UE 115-e may determine that neighbor UE 115-f is a potential hidden node.

In other examples, base station 105-d may measure the RSSI-a405 of neighbor UE 115-f. If the measured RSSI-a405 is less than a given PD threshold, base station 105-d may determine that neighbor UE 115-f may not backoff communication. That is, neighbor UE 115-f may not be capable of receiving a preamble message used to indicate reservation of a medium. For example, base station 105-d may transmit a preamble message to reserve a medium for UE 115-e. This preamble message may not be successfully heard and/or decoded by UE 115-f as the measured RSSI-a405 may be below a given PD threshold. In such instances, neighbor UE 115-f may not backoff in an autonomous uplink system and base station 105-d may determine that neighbor UE 115-f is a hidden node.

In another example, base station 105-d may determine a difference between RSSI-a 405 and RSSI-c 415. A difference that is less than or equal to given RSSI difference threshold may indicate a signal-to-interference plus noise ratio (SINR) change at base station 105-d. The value of the SINR threshold may depend on the type of neighbor node. For example, the neighbor UE 115-f may be a UE or a WiFi STA and if the difference between RSSI-a405 and RSSI-c 415 is above a RSSI difference threshold, it may be determined that the signal strength of UE 115-e is strong enough that neighbor UE 115-f will be able to hear a transmission from UE 115-e and backoff. If the measured difference is below an RSSI difference threshold, the SINR degradation may limit the ability of neighbor UE 115-f to hear a transmission from UE 115-e. Thus, neighbor UE 115-f may not backoff. In such cases, base station 105-d may then determine that neighbor UE 115-f is a hidden node.

In FIG. 4B, wireless communication system 402 includes a UE 115-g, base station 105-e, and base station 105-f, which may be examples of or may represent aspects of techniques performed by a UE 115 or a base station 105 as described with reference to FIGs 1-3. In some examples, a UE 115-g may determine whether a neighbor UE 115-f is a hidden node. This may involve determining a RSSI associated with one or more devices in wireless communication system 402. For example, UE 115-g may measure the RSSI-e 425, which may include measuring a signal (e.g., a WiFi beacon or a DRS) from base station 105-f. The UE 115-g may then compare the measured RSSI-e 425 to a given ED threshold, which may depend upon the neighbor node type. For example, if the node is a base station in an LTE system, then the ED threshold may be equal to -72 dBm. In another example, if the node is an AP in a WiFi system, then the ED threshold may be equal to -62 dBm.

If the measured RSSI is below the ED threshold, UE 115-g may determine that neighbor base station 105-f will not backoff from communication. That is, neighbor base station 105-f may not hear UE 115-g when it initiates a UL transmission or base station 105-f may hear the transmission from UE 115-g but may determine that because the transmission energy is below a given threshold, the base station 105-f is able to transmit on top of the transmission from UE 115-g. In such cases, because neighbor base station 105-f will not backoff, UE 115-g may determine that neighbor base station 105-f is a potential hidden node.

In other examples, base station 105-e may measure the RSSI-d 420 of neighbor base station 105-f. If the measured RSSI-d 420 is less than a given PD threshold, base station 105-e may determine that neighbor base station 105-f may not backoff communication. That is, neighbor base station 105-f may not be capable of receiving a preamble message used to indicate reservation of a medium. For example, base station 105-e may transmit a preamble message to reserve a medium for UE 115-g. This preamble message may not be successfully heard and/or decoded by base station 105-f as the measured RSSI-d 420 may be below a given PD threshold. In such instances, neighbor base station 105-f may not backoff in an autonomous uplink system and base station 105-e may determine that neighbor base station 105-f is a hidden node.

In another example, base station 105-e may determine a difference between RSSI-d 420 and RSSI-f 430. A difference that is less than or equal to given RSSI difference threshold may indicate a SINR change at base station 105-e. The value of the SINR threshold may depend on the type of neighbor node. For example, the neighbor base station 105-f may be a base station or a WiFi AP and if the difference between RSSI-d 420 and RSSI-f 430 is above a RSSI difference threshold, it may be determined that the signal strength of UE 115-g is strong enough that neighbor base station 105-f will be able to hear a transmission from UE 115-g and backoff. If the measured difference is below an RSSI difference threshold, the SINR degradation may limit the ability of neighbor base station 105-f to hear a transmission from UE 115-g. Thus, neighbor base station 105-f may not backoff. In such cases, base station 105-e may then determine that neighbor base station 105-f is a hidden node.

FIG. 5 illustrates an example of a process flow 500 for autonomous uplink benefit identification in accordance with one or more aspects of the present disclosure. Process flow 500 may include a UE 115-h in communication with a base station 105-g, which may be examples of or may represent aspects of techniques performed by a UE 115 or base station 105 as described with reference to FIGs. 1-4.

At 505, the base station 105-g determines a measurement scheme. The measurement scheme may include an indication to measure one or more neighboring nodes. Examples of a neighboring node may include any of a UE, a base station, an AP, or a STA that is a neighbor of UE 115-h. The indication may indicate that the UE 115-h perform a signal strength measurement (e.g., RSSI) of one or more neighboring nodes, or may indicate that the UE 115-h identify a set of neighboring nodes that may be potential hidden nodes. The UE 115-h may identify a set of neighboring nodes as potential hidden nodes based on a whether a signal strength associated with a neighboring nodes is below a threshold (e.g., an ED or PD threshold) .

At 510, base station 105-g may transmit the measurement scheme determined at 505 to UE 115-h. The measurement scheme may include a report type (e.g., periodic or triggered) indicating to UE 115-h when to report the obtained measurements to the base station 105-g.

After receiving the measurement scheme transmitted by the base station 105-g at 510, the UE 115-h may identify or measure a signal strength of one or more neighboring nodes. In some cases, UE 115-h may measure the signal strength of one or more neighboring nodes according to the measurement scheme. The neighboring node may be a UE, a base station, an AP, a STA, or any combination thereof. Based on the identified signal strength, the UE 115-h may generate a set of nodes measured according to the measurement scheme, some of which may be potential hidden nodes.

At 520, UE 115-h may transmit a hidden node indication to base station 105-g. The hidden node indication may include a signal strength indication for one or more neighboring nodes or may include a set of neighboring nodes that may be potential hidden nodes.

After receiving the hidden node indication from the UE 115-h at 520, the base station 105-g may determine that a number of hidden nodes for UE 115-h is below a given threshold at 525. In some examples, base station 105-g may identify or measure a signal strength of one or more neighboring nodes and generate a list of neighboring nodes based on the identification. The list of neighboring nodes may include potential hidden nodes for the UE 115-h. The base station 105-g may also generate a list of hidden nodes based at least in part on the hidden node indication and the signal strength from one or more neighboring nodes. For example, base station 105-g may generate a set difference between a set of nodes included in the hidden node indication and the generated list of neighboring nodes measured by base station 105-g. That is, any neighboring node in the list generated by the base station 105-g that is not in the list of nodes in the hidden node indication may be identified as a hidden node. Based on this set difference, base station 105-g may determine the number of hidden nodes, and compare the number of hidden nodes for UE 115-h to a threshold.

In some examples, base station 105-g may determine that a number of hidden nodes is below a threshold by measuring a channel metric (e.g., CQI backoff or contention window size) associated with UE 115-h. Based on this measurement, the hidden node indication, or the number of hidden nodes, the base station may select an autonomous uplink mode for UE 115-h at 520. In some examples, base station 105-g may determine that the CQI backoff metric or the contention window size is above a threshold. The base station 105-g may maintain a CQI histogram for the UE 115-h based at least in part on uplink ACK/NACK feedback from UE 115-h. This information may also be used to select an autonomous uplink mode for UE 115-h.

At 525, base station 105-g may transmit an indication of the autonomous uplink mode to UE 115-h. In some examples, the autonomous uplink mode indication may be transmitted in an RRC configuration. For instance, base station 105-g may transmit an RRC configuration to the UE 115-h including an indication to operate in an autonomous uplink mode. In other instances, the base station 105-g may transmit an RRC configuration including an indication to operate in a grant based mode, which may occur if base station 105-g determines that the CQI backoff metric is above a given threshold. At 540, once the indication is received by the UE 115-k, the UE 115-h may transmit an uplink message according to the indication.

FIG. 6 shows a block diagram 600 of a wireless device 605 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. Wireless device 605 may be an example of aspects of a base station 105 as described with reference to FIG. 1. Wireless device 605 may include receiver 610, base station communication manager 615, and transmitter 620. Wireless device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink benefit identification, etc. ) . Information may be passed on to other components of the device. The receiver 610 may be an example of aspects of the transceiver 935 described with reference to FIG. 9.

Base station communication manager 615 may be an example of aspects of the base station communication manager 915 described with reference to FIG. 9.

Base station communication manager 615 may identify a set of hidden nodes UE, select an autonomous uplink mode for the UE based on identifying the set of hidden nodes, where the autonomous uplink mode supports unscheduled uplink transmissions, and, in combination with transmitter 620, transmit an indication of the autonomous uplink mode to the UE.

Transmitter 620 may transmit signals generated by other components of the device. In some examples, the transmitter 620 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 935 described with reference to FIG. 9. The transmitter 620 may include a single antenna, or it may include a set of antennas.

FIG. 7 shows a block diagram 700 of a wireless device 705 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. Wireless device 705 may be an example of aspects of a wireless device 605 or a base station 105 as described with reference to FIGs. 1 and 6. Wireless device 705 may include receiver 710, base station communication manager 715, and transmitter 720. Wireless device 705 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink benefit identification, etc. ) . Information may be passed on to other components of the device. The receiver 710 may be an example of aspects of the transceiver 935 described with reference to FIG. 9.

Base station communication manager 715 may be an example of aspects of the base station communication manager 915 described with reference to FIG. 9.

Base station communication manager 715 may also include node identification component 725, mode selection component 730, and indication transmitting component 735.

Node identification component 725 may identify a set of hidden nodes for a UE. In some cases, identifying the set of hidden nodes for the UE includes: determining that a number of hidden nodes in the set is below a threshold. In some cases, identifying the set of hidden nodes for the UE includes: determining that a signal strength for each hidden node in the set is below a threshold. In some cases, the set of hidden nodes is identified based on the information associated with the hidden node received from the UE.

Mode selection component 730 may select an autonomous uplink mode for the UE based on identifying the set of hidden nodes, where the autonomous uplink mode supports unscheduled uplink transmissions.

Indication transmitting component 735 may transmit an indication of the autonomous uplink mode to the UE and transmit an indication to operate in a grant-based mode to the UE, where the grant-based mode supports uplink transmissions using resources assigned by a grant.

Transmitter 720 may transmit signals generated by other components of the device. In some examples, the transmitter 720 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 720 may be an example of aspects of the transceiver 935 described with reference to FIG. 9. The transmitter 720 may include a single antenna, or may include a set of antennas.

FIG. 8 shows a block diagram 800 of a base station communication manager 815 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. The base station communication manager 815 may be an example of aspects of a base station communication manager 615, a base station communication manager 715, or a base station communication manager 915 described with reference to FIGs. 6, 7, and 9. The base station communication manager 815 may include node identification component 820, mode selection component 825, indication transmitting component 830, information receiving component 835, RRC component 840, measurement component 845, threshold component 850, histogram component 855, and measurement scheme component 860. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

Node identification component 820 may identify a set of hidden nodes for a UE. In some cases, identifying the set of hidden nodes for the UE includes: determining that a number of hidden nodes in the set is below a threshold. In some cases, identifying the set of hidden nodes for the UE includes: determining that a signal strength for each hidden node in the set is below a threshold. In some cases, the set of hidden nodes is identified based on the information associated with the hidden node received from the UE.

Mode selection component 825 may select an autonomous uplink mode for the UE based on identifying the set of hidden nodes, where the autonomous uplink mode supports unscheduled uplink transmissions.

Indication transmitting component 830 may transmit an indication of the autonomous uplink mode to the UE and transmit an indication to operate in a grant-based mode to the UE, where the grant-based mode supports uplink transmissions using resources assigned by a grant.

Information receiving component 835 may receive information associated with a hidden node of the set from the UE, where the autonomous uplink mode is selected based on the information associated with the hidden node and receive information associated with a hidden node of the set from the UE, where the information associated with the hidden node includes a signal strength indication that is based on the measurement scheme. In some cases, the information associated with the hidden node includes a list of information associated with hidden nodes of the set. In some cases, the information associated with the hidden node includes an indication of a signal strength of the hidden node at the UE.

RRC component 840 may configure the indication of the autonomous uplink mode to be transmitted in a RRC message. Measurement component 845 may measure a channel metric for the UE. In some cases, the channel metric includes a channel quality indicator CQI backoff, a contention window metric, or a combination thereof. Threshold component 850 may determine that the channel metric is above a threshold. Histogram component 855 may generate a channel metric histogram for the UE, where the channel metric histogram is generated based on uplink feedback from the UE.

Measurement scheme component 860 may transmit a measurement scheme to the UE.In some cases, the measurement scheme includes an indication to measure a neighboring node and the neighbor node includes at least one of a UE, a base station, an access point, or a station, or any combination thereof. In some cases, the measurement scheme includes a periodic report type and a report interval or a triggered report type.

FIG. 9 shows a diagram of a system 900 including a device 905 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. Device 905 may be an example of or include the components of wireless device 605, wireless device 705, or a base station 105 as described above, e.g., with reference to FIGs. 1, 6 and 7. Device 905 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including base station communication manager 915, processor 920, memory 925, software 920, transceiver 935, antenna 940, network communications manager 945, and base station communications manager 950. These components may be in electronic communication via one or more busses (e.g., bus 910) . Device 905 may communicate wirelessly with one or more UEs 115.

Processor 920 may include an intelligent hardware device, (e.g., a general-purpose processor, a digital signal processor (DSP) , a central processing unit (CPU) , a microcontroller, an application-specific integrated circuit (ASIC) , an field-programmable gate array (FPGA) , a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, processor 920 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor 920. Processor 920 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting autonomous uplink benefit identification) .

Memory 925 may include random access memory (RAM) and read only memory (ROM) . The memory 925 may store computer-readable, computer-executable software 920 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 925 may contain, among other things, a basic input/output system (BIOS) which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.

Software 920 may include code to implement aspects of the present disclosure, including code to support autonomous uplink benefit identification. Software 920 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 920 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Transceiver 935 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 935 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 935 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 940. However, in some cases the device may have more than one antenna 940, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

Network communications manager 945 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 945 may manage the transfer of data communications for client devices, such as one or more UEs 115.

Base station communications manager 950 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the base station communications manager 950 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, base station communications manager 950 may provide an X2 interface within an LTE/LTE-Awireless communication network technology to provide communication between base stations 105.

FIG. 10 shows a block diagram 1000 of a wireless device 1005 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. Wireless device 1005 may be an example of aspects of a UE 115 as described with reference to FIG. 1. Wireless device 1005 may include receiver 1010, UE communication manager 1015, and transmitter 1020. Wireless device 1005 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink benefit identification, etc. ) . Information may be passed on to other components of the device. The receiver 1010 may be an example of aspects of the transceiver 1325 described with reference to FIG. 13.

UE communication manager 1015 may be an example of aspects of the UE communication manager 1315 described with reference to FIG. 13.

UE communication manager 1015 may measure a signal from a neighboring node in an unlicensed radio frequency spectrum band, transmit information associated with the measurement to a base station, receive a RRC message from the base station, the RRC message including an indication from the base station to operate in an autonomous uplink mode based on the information associated with the measurement, where the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band, and transmit an uplink message to the base station according to the autonomous uplink mode.

Transmitter 1020 may transmit signals generated by other components of the device. In some examples, the transmitter 1020 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1020 may be an example of aspects of the transceiver 1325 described with reference to FIG. 13. The transmitter 1020 may include a single antenna, or may include a set of antennas.

FIG. 11 shows a block diagram 1100 of a wireless device 1105 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. Wireless device 1105 may be an example of aspects of a wireless device 1005 or a UE 115 as described with reference to FIGs. 1 and 10. Wireless device 1105 may include receiver 1110, UE communication manager 1115, and transmitter 1120. Wireless device 1105 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

Receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to autonomous uplink benefit identification, etc. ) . Information may be passed on to other components of the device. The receiver 1110 may be an example of aspects of the transceiver 1325 described with reference to FIG. 13.

UE communication manager 1115 may be an example of aspects of the UE communication manager 1315 described with reference to FIG. 13. UE communication manager 1115 may also include signal measurement component 1125, information transmitting component 1130, RRC receiving component 1135, and message transmitting component 1140. Signal measurement component 1125 may measure a signal from a neighboring node in an unlicensed radio frequency spectrum band. In some cases, the neighboring node includes a hidden node in a set of hidden nodes.

Information transmitting component 1130 may transmit information associated with the measurement to a base station. In some cases, the information associated with the measurement includes an element in a list of neighboring nodes having a signal strength that exceeds a threshold, and transmitting the information includes transmitting a message with the list of neighboring nodes.

RRC receiving component 1135 may receive a RRC message from the base station, the RRC message including an indication from the base station to operate in an autonomous uplink mode based on the information associated with the measurement, where the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band. Message transmitting component 1140 may transmit an uplink message to the base station according to the autonomous uplink mode.

Transmitter 1120 may transmit signals generated by other components of the device. In some examples, the transmitter 1120 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1120 may be an example of aspects of the transceiver 1325 described with reference to FIG. 13. The transmitter 1120 may include a single antenna, or it may include a set of antennas.

FIG. 12 shows a block diagram 1200 of a UE communication manager 1215 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. The UE communication manager 1215 may be an example of aspects of a UE communication manager 1315 described with reference to FIGs. 10, 11, and 13. The UE communication manager 1215 may include signal measurement component 1220, information transmitting component 1225, RRC receiving component 1230, message transmitting component 1235, signal strength component 1240, indication receiving component 1245, measurement capability component 1250, measurement transmitting component 1255, and measurement receiving component 1260. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

Signal measurement component 1220 may measure a signal from a neighboring node in an unlicensed radio frequency spectrum band. In some cases, the neighboring node includes a hidden node in a set of hidden nodes.

Information transmitting component 1225 may transmit information associated with the measurement to a base station. In some cases, the information associated with the measurement includes an element in a list of neighboring nodes having a signal strength that exceeds a threshold, and transmitting the information includes transmitting a message with the list of neighboring nodes.

RRC receiving component 1230 may receive a RRC message from the base station, the RRC message including an indication from the base station to operate in an autonomous uplink mode based on the information associated with the measurement, where the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band. Message transmitting component 1235 may transmit an uplink message to the base station according to the autonomous uplink mode.

Signal strength component 1240 may determine that a strength of the signal from the neighboring node exceeds a threshold, where the information associated with the measurement is transmitted based on the determination that the strength of the signal from the neighboring node exceeds the threshold.

Indication receiving component 1245 may receive, based on a channel metric, an indication from the base station to operate in a grant-based mode, where the grant-based mode supports uplink transmissions using resources assigned by a grant from the base station. In some instances, the channel metric may include a CQI backoff, a contention window metric, or a combination thereof.

Measurement capability component 1250 may receive, from the base station, a message that includes a request for a measurement capability and transmit an additional uplink message that indicates the measurement capability in response to the request, where the measurement capability includes a WLAN signal strength capability. In some cases, the measurement capability includes a measurement parameter configuration includes a measurement frequency, a measurement dwell time, a signal strength threshold, or any combination thereof.

Measurement transmitting component 1255 may periodically transmit a result associated with the measurement to the base station and transmit a measurement result based at least on the received request.

Measurement receiving component 1260 may receive, from the base station, a request to measure the signal of the neighboring node and receive a measurement scheme from the base station, where measuring the signal from the neighboring node is based on the measurement scheme. In some cases, the neighboring node includes at least one of a UE, a neighbor base station, an access point, or a station.

FIG. 13 shows a diagram of a system 1300 including a device 1305 that supports autonomous uplink benefit identification in accordance with various aspects of the present disclosure. Device 1305 may be an example of or include the components of UE 115 as described above, e.g., with reference to FIG. 1. Device 1305 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communication manager 1315, processor 1320, memory 1325, software 1320, transceiver 1325, antenna 1340, and I/O controller 1345. These components may be in electronic communication via one or more busses (e.g., bus 1310) . Device 1305 may communicate wirelessly with one or more base stations 105.

Processor 1320 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, processor 1320 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor 1320. Processor 1320 may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting autonomous uplink benefit identification) .

Memory 1325 may include RAM and ROM. The memory 1325 may store computer-readable, computer-executable software 1320 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1325 may contain, among other things, a BIOS which may control basic hardware and/or software operation such as the interaction with peripheral components or devices.

Software 1320 may include code to implement aspects of the present disclosure, including code to support autonomous uplink benefit identification. Software 1320 may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, the software 1320 may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

Transceiver 1325 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1325 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1325 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1340. However, in some cases the device may have more than one antenna 1340, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

I/O controller 1345 may manage input and output signals for device 1305. I/O controller 1345 may also manage peripherals not integrated into device 1305. In some cases, I/O controller 1345 may represent a physical connection or port to an external peripheral. In some cases, I/O controller 1345 may utilize an operating system such as

or another known operating system.

FIG. 14 shows a flowchart illustrating a method 1400 for autonomous uplink benefit identification in accordance with various aspects of the present disclosure. The operations of method 1400 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1400 may be performed by a base station communication manager as described with reference to FIGs. 6 through 9. In some examples, a base station 105 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the base station 105 may perform aspects the functions described below using special-purpose hardware.

At block 1405 the base station 105 may identify a set of hidden nodes for a UE. The operations of block 1405 may be performed according to the methods described with reference to FIGs. 1 through 5. In certain examples, aspects of the operations of block 1405 may be performed by a node identification component as described with reference to FIGs. 6 through 9.

At block 1410 the base station 105 may select an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions. The operations of block 1410 may be performed according to the methods described with reference to FIGs. 1 through 5. In certain examples, aspects of the operations of block 1410 may be performed by a mode selection component as described with reference to FIGs. 6 through 9.

At block 1415 the base station 105 may transmit an indication of the autonomous uplink mode to the UE. The operations of block 1415 may be performed according to the methods described with reference to FIGs. 1 through 5. In certain examples, aspects of the operations of block 1415 may be performed by an indication transmitting component as described with reference to FIGs. 6 through 9.

FIG. 15 shows a flowchart illustrating a method 1500 for autonomous uplink benefit identification in accordance with various aspects of the present disclosure. The operations of method 1500 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1500 may be performed by a UE communication manager as described with reference to FIGs. 10 through 13. In some examples, a UE 115 may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE 115 may perform aspects the functions described below using special-purpose hardware.

At block 1505 the UE 115 may measure a signal from a neighboring node in an unlicensed radio frequency spectrum band. The operations of block 1505 may be performed according to the methods described with reference to FIGs. 1 through 5. In certain examples, aspects of the operations of block 1505 may be performed by a signal measurement component as described with reference to FIGs. 10 through 13.

At block 1510 the UE 115 may transmit information associated with the measurement to a base station. The operations of block 1510 may be performed according to the methods described with reference to FIGs. 1 through 5. In certain examples, aspects of the operations of block 1510 may be performed by an information transmitting component as described with reference to FIGs. 10 through 13.

At block 1515 the UE 115 may receive a RRC message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band. The operations of block 1515 may be performed according to the methods described with reference to FIGs. 1 through 5. In certain examples, aspects of the operations of block 1515 may be performed by a RRC receiving component as described with reference to FIGs. 10 through 13.

At block 1520 the UE 115 may transmit an uplink message to the base station according to the autonomous uplink mode. The operations of block 1520 may be performed according to the methods described with reference to FIGs. 1 through 5. In certain examples, aspects of the operations of block 1520 may be performed by a message transmitting component as described with reference to FIGs. 10 through 13.

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

Techniques described herein may be used for various wireless communications systems such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , single carrier frequency division multiple access (SC-FDMA) , and other systems. The terms “system” and “network” are often used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases may be commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) .

An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications system (UMTS) . 3GPP LTE and LTE-A) are releases of Universal Mobile Telecommunications System (UMTS) that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and Global System for Mobile communications (GSM) are described in documents from the organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies. While aspects an LTE system may be described for purposes of example, and LTE terminology may be used in much of the description, the techniques described herein are applicable beyond LTE applications.

In LTE/LTE-Anetworks, including such networks described herein, the term evolved node B (eNB) may be generally used to describe the base stations. The wireless communications system or systems described herein may include a heterogeneous LTE/LTE-A network in which different types of evolved node B (eNBs) provide coverage for various geographical regions. For example, each eNB or base station may provide communication coverage for a macro cell, a small cell, or other types of cell. The term “cell” may be used to describe a base station, a carrier or component carrier associated with a base station, or a coverage area (e.g., sector, etc. ) of a carrier or base station, depending on context.

Base stations may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, eNodeB, Home NodeB, a Home eNodeB, or some other suitable terminology. The geographic coverage area for a base station may be divided into sectors making up only a portion of the coverage area. The wireless communications system or systems described herein may include base stations of different types (e.g., macro or small cell base stations) . The UEs described herein may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like. There may be overlapping geographic coverage areas for different technologies.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell is a lower-powered base station, as compared with a macro cell, that may operate in the same or different (e.g., licensed, unlicensed, etc. ) frequency bands as macro cells. Small cells may include pico cells, femto cells, and micro cells according to various examples. A pico cell, for example, may cover a small geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or multiple (e.g., two, three, four, and the like) cells (e.g., component carriers) . A UE may be able to communicate with various types of base stations and network equipment including macro eNBs, small cell eNBs, relay base stations, and the like.

The wireless communications system or systems described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for either synchronous or asynchronous operations.

The downlink transmissions described herein may also be called forward link transmissions while the uplink transmissions may also be called reverse link transmissions. Each communication link described herein—including, for example, wireless communications system 100 and 200 of FIGs. 1 and 2—may include one or more carriers, where each carrier may be a signal made up of multiple sub-carriers (e.g., waveform signals of different frequencies) .

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 “exemplary” 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, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

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.

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 above 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 modules described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, 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 conventional 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) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on 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 above can 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. Also, as used herein, including in the claims, “or” as used in a list of items (for example, 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 exemplary 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. ”

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 place to another. A non-transitory storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may comprise RAM, ROM, electrically erasable programmable read only memory (EEPROM) , compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can 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 medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

The description herein is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled 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 method for wireless communication, comprising:

identifying a set of hidden nodes for a user equipment (UE) ；

selecting an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions； and

transmitting an indication of the autonomous uplink mode to the UE.
The method of claim 1, wherein identifying the set of hidden nodes for the UE comprises:

determining that a number of hidden nodes in the set is below a threshold.
The method of claim 1, wherein identifying the set of hidden nodes for the UE comprises:

determining that a signal strength for each hidden node in the set is below a threshold.
The method of claim 1, further comprising:

receiving information associated with a hidden node of the set from the UE, wherein the autonomous uplink mode is selected based at least in part on the information associated with the hidden node.
The method of claim 4, wherein the information associated with the hidden node comprises a list of information associated with hidden nodes of the set.
The method of claim 4, wherein the information associated with the hidden node comprises an indication of a signal strength of the hidden node at the UE.
The method of claim 1, wherein transmitting the indication of the autonomous uplink mode comprises:

transmitting the indication of the autonomous uplink mode in a radio resource control (RRC) message.
The method of claim 1, further comprising:

measuring a channel metric for the UE；

determining that the channel metric is above a threshold； and

transmitting an indication to operate in a grant-based mode to the UE, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant.
The method of claim 8, further comprising:

generating a channel metric histogram for the UE, wherein the channel metric histogram is generated based at least in part on uplink feedback from the UE.
The method of claim 8, wherein the channel metric comprises a channel quality indicator (CQI) backoff, a contention window metric, or a combination thereof.
The method of claim 1, further comprising:

transmitting a measurement scheme to the UE；

receiving information associated with a hidden node of the set from the UE, wherein the information associated with the hidden node comprises a signal strength indication that is based at least in part on the measurement scheme； and

wherein the set of hidden nodes is identified based at least in part on the information associated with the hidden node received from the UE.
The method of claim 11, wherein the measurement scheme comprises an indication to measure a neighboring node and the neighboring node comprises at least one of a UE, a base station, an access point, or a station, or any combination thereof.
The method of claim 11, wherein the measurement scheme comprises a periodic report type and a report interval or a triggered report type.
A method for wireless communication, comprising:

measuring a signal from a neighboring node in an unlicensed radio frequency spectrum band；

transmitting information associated with the measurement to a base station；

receiving a radio resource control (RRC) message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band； and

transmitting an uplink message to the base station according to the autonomous uplink mode.
The method of claim 14, further comprising:

determining that a strength of the signal from the neighboring node exceeds a threshold, wherein the information associated with the measurement is transmitted based at least in part on the determination that the strength of the signal from the neighboring node exceeds the threshold.
The method of claim 14, wherein the information associated with the measurement comprises an element in a list of neighboring nodes having a signal strength that exceeds a threshold, and transmitting the information comprises:

transmitting a message with the list of neighboring nodes.
The method of claim 14, further comprising:

receiving, based at least in part on a channel metric, an indication from the base station to operate in a grant-based mode, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant from the base station.
The method of claim 17, wherein the channel metric comprises a channel quality indicator (CQI) backoff, a contention window metric, or a combination thereof.
The method of claim 14, further comprising:

receiving, from the base station, a message that comprises a request for a measurement capability； and

transmitting an additional uplink message that indicates the measurement capability in response to the request, wherein the measurement capability comprises a wireless local area network (WLAN) signal strength capability.
The method of claim 19, wherein the measurement capability comprises a measurement parameter configuration comprising a measurement frequency, a measurement dwell time, a signal strength threshold, or any combination thereof.
The method of claim 14, further comprising:

periodically transmitting a result associated with the measurement to the base station.
The method of claim 14, further comprising:

receiving, from the base station, a request to measure the signal of the neighboring node； and

transmitting a measurement result based at least on the received request.
The method of claim 14, further comprising:

receiving a measurement scheme from the base station, wherein measuring the signal from the neighboring node is based at least in part on the measurement scheme.
The method of claim 23, wherein the neighboring node comprises at least one of a user equipment (UE) , a neighbor base station, an access point, or a station.
The method of claim 14, wherein the neighboring node comprises a hidden node in a set of hidden nodes.
An apparatus for wireless communication, comprising:

means for identifying a set of hidden nodes for a user equipment (UE) ；

means for selecting an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions； and

means for transmitting an indication of the autonomous uplink mode to the UE.
The apparatus of claim 26, wherein the means for identifying the set of hidden nodes for the UE comprises:

means for determining that a number of hidden nodes in the set is below a threshold.
The apparatus of claim 26, wherein the means for identifying the set of hidden nodes for the UE comprises:

means for determining that a signal strength for each hidden node in the set is below a threshold.
The apparatus of claim 26, further comprising:

means for receiving information associated with a hidden node of the set from the UE, wherein the means for selecting the autonomous uplink mode is operable based at least in part on the information associated with the hidden node.
The apparatus of claim 29, wherein the information associated with the hidden node comprises a list of information associated with hidden nodes of the set.
The apparatus of claim 29, wherein the information associated with the hidden node comprises an indication of a signal strength of the hidden node at the UE.
The apparatus of claim 26, wherein the means for transmitting the indication of the autonomous uplink mode comprises:

means for transmitting the indication of the autonomous uplink mode in a radio resource control (RRC) message.
The apparatus of claim 26, further comprising:

means for measuring a channel metric for the UE；

means for determining that the channel metric is above a threshold； and

means for transmitting an indication to operate in a grant-based mode to the UE, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant.
The apparatus of claim 33, further comprising:

means for generating a channel metric histogram for the UE, wherein the channel metric histogram is generated based at least in part on uplink feedback from the UE.
The apparatus of claim 33, wherein the channel metric comprises a channel quality indicator (CQI) backoff, a contention window metric, or a combination thereof.
The apparatus of claim 26, further comprising:

means for transmitting a measurement scheme to the UE；

means for receiving information associated with a hidden node of the set from the UE, wherein the information associated with the hidden node comprises a signal strength indication that is based at least in part on the measurement scheme； and

wherein the means for identifying the set of hidden nodes is operable based at least in part on the information associated with the hidden node received from the UE.
The apparatus of claim 36, wherein the measurement scheme comprises an indication to measure a neighboring node and the neighboring node comprises at least one of a UE, a base station, an access point, or a station, or any combination thereof.
The apparatus of claim 36, wherein the measurement scheme comprises a periodic report type and a report interval or a triggered report type.
An apparatus for wireless communication, comprising:

means for measuring a signal from a neighboring node in an unlicensed radio frequency spectrum band；

means for transmitting information associated with the measurement to a base station；

means for receiving a radio resource control (RRC) message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band； and

means for transmitting an uplink message to the base station according to the autonomous uplink mode.
The apparatus of claim 39, further comprising:

means for determining that a strength of the signal from the neighboring node exceeds a threshold, wherein the means for transmitting the information associated with the measurement is operable based at least in part on the determination that the strength of the signal from the neighboring node exceeds the threshold.
The apparatus of claim 39, wherein the information associated with the measurement comprises an element in a list of neighboring nodes having a signal strength that exceeds a threshold, and the means for transmitting the information comprises:

means for transmitting a message with the list of neighboring nodes.
The apparatus of claim 39, further comprising:

means for receiving, based at least in part on a channel metric, an indication from the base station to operate in a grant-based mode, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant from the base station.
The apparatus of claim 42, wherein the channel metric comprises a channel quality indicator (CQI) backoff, a contention window metric, or a combination thereof.
The apparatus of claim 39, further comprising:

means for receiving, from the base station, a message that comprises a request for a measurement capability； and

means for transmitting an additional uplink message that indicates the measurement capability in response to the request, wherein the measurement capability comprises a wireless local area network (WLAN) signal strength capability.
The apparatus of claim 44, wherein the measurement capability comprises a measurement parameter configuration comprising a measurement frequency, a measurement dwell time, a signal strength threshold, or any combination thereof.
The apparatus of claim 39, further comprising:

means for periodically transmitting a result associated with the measurement to the base station.
The apparatus of claim 39, further comprising:

means for receiving, from the base station, a request to measure the signal of the neighboring node； and

means for transmitting a measurement result based at least on the received request.
The apparatus of claim 39, further comprising:

means for receiving a measurement scheme from the base station, wherein the means for measuring the signal from the neighboring node is operable based at least in part on the measurement scheme.
The apparatus of claim 48, wherein the neighboring node comprises at least one of a user equipment (UE) , a neighbor base station, an access point, or a station.
The apparatus of claim 39, wherein the neighboring node comprises a hidden node in a set of hidden nodes.
An apparatus for wireless communication, in a system comprising:

a processor；

memory in electronic communication with the processor； and

instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:

identify a set of hidden nodes for a user equipment (UE) ；

select an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions； and

transmit an indication of the autonomous uplink mode to the UE.
The apparatus of claim 51, wherein the instructions are executable by the processor to cause the apparatus to:

determine that a number of hidden nodes in the set is below a threshold.
The apparatus of claim 51, wherein the instructions are executable by the processor to cause the apparatus to:

determine that a signal strength for each hidden node in the set is below a threshold.
The apparatus of claim 51, wherein the instructions are executable by the processor to cause the apparatus to:

receive information associated with a hidden node of the set from the UE； and

select the autonomous uplink mode based at least in part on the information associated with the hidden node.
The apparatus of claim 54, wherein the information associated with the hidden node comprises a list of information associated with hidden nodes of the set.
The apparatus of claim 54, wherein the information associated with the hidden node comprises an indication of a signal strength of the hidden node at the UE.
The apparatus of claim 51, wherein the instructions are executable by the processor to cause the apparatus to:

transmit the indication of the autonomous uplink mode comprises:

transmitting the indication of the autonomous uplink mode in a radio resource control (RRC) message.
The apparatus of claim 51, wherein the instructions are executable by the processor to cause the apparatus to:

measure a channel metric for the UE；

determine that the channel metric is above a threshold； and

transmit an indication to operate in a grant-based mode to the UE, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant.
The apparatus of claim 58, wherein the instructions are executable by the processor to cause the apparatus to:

generate a channel metric histogram for the UE, wherein the channel metric histogram is generated based at least in part on uplink feedback from the UE.
The apparatus of claim 59, wherein the channel metric comprises a channel quality indicator (CQI) backoff, a contention window metric, or a combination thereof.
The apparatus of claim 51, wherein the instructions are executable by the processor to cause the apparatus to:

transmit a measurement scheme to the UE；

receive information associated with a hidden node of the set from the UE, wherein the information associated with the hidden node comprises a signal strength indication that is based at least in part on the measurement scheme； and

identify the set of hidden nodes based at least in part on the information associated with the hidden node received from the UE.
The apparatus of claim 61, wherein the measurement scheme comprises an indication to measure a neighboring node and the neighboring node comprises at least one of a UE, a base station, an access point, or a station, or any combination thereof.
The apparatus of claim 61, wherein the measurement scheme comprises a periodic report type and a report interval or a triggered report type.
An apparatus for wireless communication, in a system comprising:

a processor；

memory in electronic communication with the processor； and

instructions stored in the memory and operable, when executed by the processor, to cause the apparatus to:

measure a signal from a neighboring node in an unlicensed radio frequency spectrum band；

transmit information associated with the measurement to a base station；

receive a radio resource control (RRC) message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band； and

transmit an uplink message to the base station according to the autonomous uplink mode.
The apparatus of claim 64, wherein the instructions are executable by the processor to cause the apparatus to:

determine that a strength of the signal from the neighboring node exceeds a threshold； and

transmit the information associated with the measurement based at least in part on a determination that the strength of the signal from the neighboring node exceeds the threshold.
The apparatus of claim 64, wherein the information associated with the measurement comprises an element in a list of neighboring nodes having a signal strength that exceeds a threshold, and wherein the instructions are executable by the processor to cause the apparatus to:

transmit a message with the list of neighboring nodes.
The apparatus of claim 64, wherein the instructions are executable by the processor to cause the apparatus to:

receive, based at least in part on a channel metric, an indication from the base station to operate in a grant-based mode, wherein the grant-based mode supports uplink transmissions using resources assigned by a grant from the base station.
The apparatus of claim 67, wherein the channel metric comprises a channel quality indicator (CQI) backoff, a contention window metric, or a combination thereof.
The apparatus of claim 64, wherein the instructions are executable by the processor to cause the apparatus to:

receive, from the base station, a message that comprises a request for a measurement capability； and

transmit an additional uplink message that indicates the measurement capability in response to the request, wherein the measurement capability comprises a wireless local area network (WLAN) signal strength capability.
The apparatus of claim 69, wherein the measurement capability comprises a measurement parameter configuration comprising a measurement frequency, a measurement dwell time, a signal strength threshold, or any combination thereof.
The apparatus of claim 64, wherein the instructions are executable by the processor to cause the apparatus to:

periodically transmit a result associated with the measurement to the base station.
The apparatus of claim 64, wherein the instructions are executable by the processor to cause the apparatus to:

receive, from the base station, a request to measure the signal of the neighboring node； and

transmit a measurement result based at least on the received request.
The apparatus of claim 64, wherein the instructions are executable by the processor to cause the apparatus to:

receive a measurement scheme from the base station； and

measure the signal from the neighboring node based at least in part on the measurement scheme.
The apparatus of claim 73, wherein the neighboring node comprises at least one of a user equipment (UE) , a neighbor base station, an access point, or a station.
The apparatus of claim 64, wherein the neighboring node comprises a hidden node in a set of hidden nodes.
A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable to:

identify a set of hidden nodes for a user equipment (UE) ；

select an autonomous uplink mode for the UE based at least in part on identifying the set of hidden nodes, wherein the autonomous uplink mode supports unscheduled uplink transmissions； and

transmit an indication of the autonomous uplink mode to the UE.
A non-transitory computer readable medium storing code for wireless communication, the code comprising instructions executable to:

measure a signal from a neighboring node in an unlicensed radio frequency spectrum band；

transmit information associated with the measurement to a base station；

receive a radio resource control (RRC) message from the base station, the RRC message comprising an indication from the base station to operate in an autonomous uplink mode based at least in part on the information associated with the measurement, wherein the autonomous uplink mode supports unscheduled uplink transmissions in the unlicensed radio frequency spectrum band； and

transmit an uplink message to the base station according to the autonomous uplink mode.