WO2024174125A1

WO2024174125A1 - Wireless communication survival time enhancements in shared spectrum

Info

Publication number: WO2024174125A1
Application number: PCT/CN2023/077643
Authority: WO
Inventors: Luanxia YANG; Xiaoxia Zhang; Changlong Xu; Jing Sun; Chih-Hao Liu; Shaozhen GUO; Siyi Chen
Original assignee: Qualcomm Incorporated
Priority date: 2023-02-22
Filing date: 2023-02-22
Publication date: 2024-08-29

Abstract

Wireless communications systems, apparatuses, and methods are provided. A method of wireless communication performed by a first wireless communication device includes performing a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs), transmitting, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs, and performing a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

Description

WIRELESS COMMUNICATION SURVIVAL TIME ENHANCEMENTS IN SHARED SPECTRUM

TECHNICAL FIELD

This application relates to wireless communication systems, and more particularly, to enhancing wireless communication survival time in shared spectrum wireless communication systems.

INTRODUCTION

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) . A wireless multiple-access communications system may include a number of base stations (BSs) , each simultaneously supporting communications for multiple communication devices, which may be otherwise known as user equipment (UE) .

To meet the growing demands for expanded mobile broadband connectivity, wireless communication technologies are advancing from the LTE technology to a next generation new radio (NR) technology. For example, NR is designed to provide a lower latency, a higher bandwidth or throughput, and a higher reliability than LTE. NR is designed to operate over a wide array of spectrum bands, for example, from low-frequency bands below about 1 gigahertz (GHz) and mid-frequency bands from about 1 GHz to about 6 GHz, to high-frequency bands such as millimeter wave (mmWave) bands. NR is also designed to operate across different spectrum types, from licensed spectrum to unlicensed and shared spectrum. Spectrum sharing enables operators to opportunistically aggregate spectrums to dynamically support high-bandwidth services. Spectrum sharing may extend the benefit of NR technologies to operating entities that may not have access to a licensed spectrum.

NR may support various deployment scenarios to benefit from the various spectrums in different frequency ranges, licensed and/or unlicensed, and/or coexistence of the LTE and NR technologies. For example, NR may be deployed in a standalone NR mode over a licensed and/or an unlicensed band or in a dual connectivity mode with various combinations of NR and LTE over licensed and/or unlicensed bands.

In a wireless communication network, a BS may communicate with a UE in an uplink direction and a downlink direction. Sidelink was introduced in LTE to allow a UE to send data to another UE (e.g., from one vehicle to another vehicle) without tunneling through the BS and/or an associated core network. The LTE sidelink technology has been extended to provision for device-to-device (D2D) communications, vehicle-to-everything (V2X) communications, and/or cellular vehicle-to-everything (C-V2X) communications. Similarly, NR may be extended to support sidelink communications, D2D communications, V2X communications, and/or C-V2X over licensed frequency bands and/or unlicensed frequency bands (e.g., shared frequency bands) .

BRIEF SUMMARY OF SOME EXAMPLES

The following summarizes some aspects of the present disclosure to provide a basic understanding of the discussed technology. This summary is not an extensive overview of all contemplated features of the disclosure and is intended neither to identify key or critical elements of all aspects of the disclosure nor to delineate the scope of any or all aspects of the disclosure. Its sole purpose is to present some concepts of one or more aspects of the disclosure in summary form as a prelude to the more detailed description that is presented later.

In an aspect of the disclosure, a method of wireless communication performed by a first wireless communication device may include performing a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) ; transmitting, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs; and performing a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

In an additional aspect of the disclosure, a method of wireless communication performed by a first wireless communication device may include transmitting, to a second wireless communication device, an indicator indicating a survival time associated with a plurality of TBs; performing a listen-before-talk (LBT) procedure in a shared frequency band; transmitting, to the second wireless communication device based on the LBT procedure being successful, a channel occupancy time (COT) sharing request; receiving, from the second wireless communication device, an indicator to share the COT; and transmitting, during the COT, one or more TBs of the plurality of TBs.

In an additional aspect of the disclosure, a first wireless communication device may include a memory; a transceiver; and at least one processor coupled to the memory and the transceiver, wherein the first wireless communication device is configured to: perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) ; transmit, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs; and perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

In an additional aspect of the disclosure, a first wireless communication device may include a memory; a transceiver; and at least one processor coupled to the memory and the transceiver, wherein the first wireless communication device is configured to: transmit, to a second wireless communication device, an indicator indicating a survival time associated with a plurality of TBs; perform a listen-before-talk (LBT) procedure in a shared frequency band; transmit, to the second wireless communication device based on the LBT procedure being successful, a channel occupancy time (COT) sharing request; receive from the second wireless communication device, an indicator to share the COT; and transmit, during the COT, one or more TBs of the plurality of TBs.

Other aspects, features, and instances of the present invention will become apparent to those of ordinary skill in the art, upon reviewing the following description of specific, exemplary instances of the present invention in conjunction with the accompanying figures. While features of the present invention may be discussed relative to certain aspects and figures below, all instances of the present invention may include one or more of the advantageous features discussed herein. In other words, while one or more instances may be discussed as having certain advantageous features, one or more of such features may also be used in accordance with the various instances of the invention discussed herein. In similar fashion, while exemplary aspects may be discussed below as device, system, or method instances it should be understood that such exemplary instances may be implemented in various devices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a wireless communication network according to some aspects of the present disclosure.

FIG. 2 illustrates an example disaggregated base station architecture according to some aspects of the present disclosure.

FIG. 3 illustrates survival time in wireless communications according to some aspects of the present disclosure.

FIG. 4 illustrates LBT procedures during survival time in wireless communications according to some aspects of the present disclosure.

FIG. 5 illustrates LBT procedures during survival time in wireless communications according to some aspects of the present disclosure.

FIG. 6 is a signal flow diagram of a communication method according to some aspects of the present disclosure.

FIG. 7 is a signal flow diagram of a communication method according to some aspects of the present disclosure.

FIG. 8 is a block diagram of an exemplary user equipment (UE) according to some aspects of the present disclosure.

FIG. 9 is a block diagram of an exemplary network unit according to some aspects of the present disclosure.

FIG. 10 is a flow diagram of a communication method according to some aspects of the present disclosure.

FIG. 11 is a flow diagram of a communication method according to some aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below, in connection with the appended drawings, is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

This disclosure relates generally to wireless communications systems, also referred to as wireless communications networks. In various instances, the techniques and apparatus may be used for wireless communication networks such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5^th Generation (5G) or new radio (NR) networks, as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA) , Institute of Electrical and Electronic Engineers (IEEE) 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are part of universal mobile telecommunication system (UMTS) . In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3^rd Generation Partnership Project” (3GPP) , and cdma2000 is described in documents from an organization named “3^rd Generation Partnership Project 2” (3GPP2) . These various radio technologies and standards are known or are being developed. For example, the 3^rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the universal mobile telecommunications system (UMTS) mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

In particular, 5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. In order to achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ～1M nodes/km2) , ultra-low complexity (e.g., ～10s of bits/sec) , ultra-low energy (e.g., ～10+ years of battery life) , and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ～99.9999%reliability) , ultra-low latency (e.g., ～ 1 ms) , and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ～ 10 Tbps/km2) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.

The 5G NR may be implemented to use optimized OFDM-based waveforms with scalable numerology and transmission time interval (TTI) ; having a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and with advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 5, 10, 20 MHz, and the like bandwidth (BW) . For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz BW.For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz BW. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500MHz BW.

The scalable numerology of the 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive uplink/downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet the current traffic needs.

Various other aspects and features of the disclosure are further described below. It should be apparent that the teachings herein may be embodied in a wide variety of forms and that any specific structure, function, or both being disclosed herein is merely representative and not limiting. Based on the teachings herein one of an ordinary level of skill in the art should appreciate that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. In addition, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more of the aspects set forth herein. For example, a method may be implemented as part of a system, device, apparatus, and/or as instructions stored on a computer readable medium for execution on a processor or computer. Furthermore, an aspect may include at least one element of a claim.

The deployment of NR over an unlicensed spectrum is referred to as NR-unlicensed (NR-U) . Federal Communications Commission (FCC) and European Telecommunications Standards Institute (ETSI) are working on regulating 6 GHz as a new unlicensed band for wireless communications. The addition of 6 GHz bands allows for hundreds of megahertz (MHz) of bandwidth (BW) available for unlicensed band communications. Additionally, NR-U may also be deployed over 2.4 GHz unlicensed bands, which are currently shared by various radio access technologies (RATs) , such as IEEE 802.11 wireless local area network (WLAN) or WiFi and/or license assisted access (LAA) . Sidelink communications may benefit from utilizing the additional bandwidth available in an unlicensed spectrum. However, channel access in a certain unlicensed spectrum may be regulated by authorities. For instance, some unlicensed bands may impose restrictions on the power spectral density (PSD) and/or minimum occupied channel bandwidth (OCB) for transmissions in the unlicensed bands. For example, the unlicensed national information infrastructure (UNII) radio band has a minimum OCB requirement of about at least 70 percent (%) .

Some sidelink systems may operate over a 20 MHz bandwidth, e.g., for listen before talk (LBT) based channel accessing, in an unlicensed band. A BS may configure a sidelink resource pool over one or multiple 20 MHz LBT sub-bands for sidelink communications. A sidelink resource pool is typically allocated with multiple frequency subchannels within a sidelink band width part (SL-BWP) and a sidelink UE may select a sidelink resource (e.g., one or multiple subchannel) in frequency and one or multiple slots in time) from the sidelink resource pool for sidelink communication.

Deployment of communication systems, such as 5G new radio (NR) systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element, or a network equipment, such as a base station (BS) , or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a BS (such as a Node B (NB) , evolved NB (eNB) , NR BS, 5G NB, access point (AP) , a transmit receive point (TRP) , or a cell, etc. ) may be implemented as an aggregated base station (also known as a standalone BS or a monolithic BS) or a disaggregated base station.

An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs) , one or more distributed units (DUs) , or one or more radio units (RUs) ) . In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU also may be implemented as virtual units, i.e., a virtual central unit (VCU) , a virtual distributed unit (VDU) , or a virtual radio unit (VRU) .

Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (such as the network configuration sponsored by the O-RAN Alliance) ) , or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN) ) . Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which may enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, may be configured for wired or wireless communication with at least one other unit.

Various aspects relate generally to wireless communication and more particularly to signaling for dynamic waveform switching. Some aspects more specifically relate to a network unit signaling a user equipment (UE) to switch between a first waveform type and a second waveform type for uplink communications. In some examples, a network unit may transmit an indicator to the UE to enable switching between the waveform types. When waveform switching is enabled, the network unit may transmit DCI to the UE indicating which waveform type to use for uplink communications. In some examples, the size of the DCI may be the same size for the first waveform type and the second waveform type. As such, the UE may blind decode the DCI using a common DCI size for the first waveform type and the second waveform type. The DCI may further include scheduled resources for a physical uplink shared channel (PUSCH) communication associated with the UE. The UE may transmit PUSCH communications to the network unit via the scheduled resources using the indicated waveform type.

Additionally or alternatively, the UE may switch between the first waveform type and the second waveform type on a semi-static basis. In some examples, a network unit may transmit an indicator to the UE to enable switching between the waveform types. When waveform switching is enabled, the network unit may transmit non-uplink scheduling DCI and/or a MAC-CE communication to the UE indicating which waveform type to use for uplink communications. The network unit may subsequently transmit uplink scheduling DCI to the UE using a DCI size associated with the previously indicated waveform type. The DCI size associated with the first waveform type may be different from the DCI associated with the second waveform type. As such, the UE may blind decode the DCI based on the DCI size associated with the indicated waveform type. The UE may transmit PUSCH communications to the network unit via the scheduled resources using the indicated waveform type.

Particular aspects of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages. In some examples, by implementing dynamic waveform switching according to embodiments of the present disclosure, the described techniques may be used to reduce computing resources, memory requirements, latency, and/or power consumption in the UE by blind decoding a DCI having a common size for the first and second waveform types as compared to blind decoding a first DCI associated with the first waveform type and blind decoding a second, different sized DCI associated with the second waveform type. The dynamic waveform switching according to embodiments of the present disclosure may increase network coverage and/or network capacity. For example, the UE may switch to transmitting uplink communications using a DFT-s-OFDM waveform to increase range and coverage. In some examples, the UE may switch to transmitting uplink communications using a CP-OFDM waveform to increase throughput and/or data rate.

FIG. 1 illustrates a wireless communication network 100 according to some aspects of the present disclosure. The network 100 includes a number of base stations (BSs) 105 and other network entities. A BS 105 may be a station that communicates with UEs 115 and may also be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like. Each BS 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” may refer to this particular geographic coverage area of a BS 105 and/or a BS subsystem serving the coverage area, depending on the context in which the term is used.

A BS 105 may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. 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, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also 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) . A BS for a macro cell may be referred to as a macro BS. A BS for a small cell may be referred to as a small cell BS, a pico BS, a femto BS or a home BS. In the example shown in FIG. 1, the BSs 105d and 105e may be regular macro BSs, while the BSs 105a-105c may be macro BSs enabled with one of three dimension (3D) , full dimension (FD) , or massive MIMO. The BSs 105a-105c may take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. The BS 105f may be a small cell BS which may be a home node or portable access point. A BS 105 may support one or multiple (e.g., two, three, four, and the like) cells.

The network 100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.

The UEs 115 are dispersed throughout the wireless network 100, and each UE 115 may be stationary or mobile. A UE 115 may also be referred to as a terminal, a mobile station, a subscriber unit, a station, or the like. A UE 115 may be a cellular phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a tablet computer, a laptop computer, a cordless phone, a wireless local loop (WLL) station, or the like. In one aspect, a UE 115 may be a device that includes a Universal Integrated Circuit Card (UICC) . In another aspect, a UE may be a device that does not include a UICC. In some aspects, the UEs 115 that do not include UICCs may also be referred to as IoT devices or internet of everything (IoE) devices. The UEs 115a-115d are examples of mobile smart phone-type devices accessing network 100. A UE 115 may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like. The UEs 115e-115h are examples of various machines configured for communication that access the network 100. The UEs 115i-115k are examples of vehicles equipped with wireless communication devices configured for communication that access the network 100. A UE 115 may be able to communicate with any type of the BSs, whether macro BS, small cell, or the like. In FIG. 1, a lightning bolt (e.g., communication links) indicates wireless transmissions between a UE 115 and a serving BS 105, which is a BS designated to serve the UE 115 on the downlink (DL) and/or uplink (UL) , desired transmission between BSs 105, backhaul transmissions between BSs, or sidelink transmissions between UEs 115.

In operation, the BSs 105a-105c may serve the UEs 115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. The macro BS 105d may perform backhaul communications with the BSs 105a-105c, as well as small cell, the BS 105f. The macro BS 105d may also transmits multicast services which are subscribed to and received by the UEs 115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

The BSs 105 may also communicate with a core network. The core network may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. At least some of the BSs 105 (e.g., which may be an example of an evolved NodeB (eNB) or an access node controller (ANC) ) may interface with the core network 130 through backhaul links (e.g., S1, S2, etc. ) and may perform radio configuration and scheduling for communication with the UEs 115. In various examples, the BSs 105 may communicate, either directly or indirectly (e.g., through core network) , with each other over backhaul links (e.g., X1, X2, etc. ) , which may be wired or wireless communication links.

The network 100 may also support mission critical communications with ultra-reliable and redundant links for mission critical devices, such as the UE 115e, which may be a vehicle (e.g., a car, a truck, a bus, an autonomous vehicle, an aircraft, a boat, etc. ) . Redundant communication links with the UE 115e may include links from the macro BSs 105d and 105e, as well as links from the small cell BS 105f. Other machine type devices, such as the UE 115f (e.g., a thermometer) , the UE 115g (e.g., smart meter) , and UE 115h (e.g., wearable device) may communicate through the network 100 either directly with BSs, such as the small cell BS 105f, and the macro BS 105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as the UE 115f communicating temperature measurement information to the smart meter, the UE 115g, which is then reported to the network through the small cell BS 105f. In some aspects, the UE 115h may harvest energy from an ambient environment associated with the UE 115h. The network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as vehicle-to-vehicle (V2V) , vehicle-to-everything (V2X) , cellular-vehicle-to-everything (C-V2X) communications between a UE 115i, 115j, or 115k and other UEs 115, and/or vehicle-to-infrastructure (V2I) communications between a UE 115i, 115j, or 115k and a BS 105.

In some implementations, the network 100 utilizes OFDM-based waveforms for communications. An OFDM-based system may partition the system BW into multiple (K) orthogonal subcarriers, which are also commonly referred to as subcarriers, tones, bins, or the like. Each subcarrier may be modulated with data. In some instances, the subcarrier spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system BW. The system BW may also be partitioned into subbands. In other instances, the subcarrier spacing and/or the duration of TTIs may be scalable.

In some instances, the BSs 105 may assign or schedule transmission resources (e.g., in the form of time-frequency resource blocks (RB) ) for downlink (DL) and uplink (UL) transmissions in the network 100. DL refers to the transmission direction from a BS 105 to a UE 115, whereas UL refers to the transmission direction from a UE 115 to a BS 105. The communication may be in the form of radio frames. A radio frame may be divided into a plurality of subframes, for example, about 10. Each subframe may be divided into slots, for example, about 2. Each slot may be further divided into mini-slots. In a FDD mode, simultaneous UL and DL transmissions may occur in different frequency bands. For example, each subframe includes a UL subframe in a UL frequency band and a DL subframe in a DL frequency band. In a TDD mode, UL and DL transmissions occur at different time periods using the same frequency band. For example, a subset of the subframes (e.g., DL subframes) in a radio frame may be used for DL transmissions and another subset of the subframes (e.g., UL subframes) in the radio frame may be used for UL transmissions.

The DL subframes and the UL subframes may be further divided into several regions. For example, each DL or UL subframe may have pre-defined regions for transmissions of reference signals, control information, and data. Reference signals are predetermined signals that facilitate the communications between the BSs 105 and the UEs 115. For example, a reference signal may have a particular pilot pattern or structure, where pilot tones may span across an operational BW or frequency band, each positioned at a pre-defined time and a pre-defined frequency. For example, a BS 105 may transmit cell specific reference signals (CRSs) and/or channel state information -reference signals (CSI-RSs) to enable a UE 115 to estimate a DL channel. Similarly, a UE 115 may transmit sounding reference signals (SRSs) to enable a BS 105 to estimate a UL channel. Control information may include resource assignments and protocol controls. Data may include protocol data and/or operational data. In some instances, the BSs 105 and the UEs 115 may communicate using self-contained subframes. A self-contained subframe may include a portion for DL communication and a portion for UL communication. A self-contained subframe may be DL-centric or UL-centric. A DL- centric subframe may include a longer duration for DL communication than for UL communication. A UL-centric subframe may include a longer duration for UL communication than for UL communication.

In some instances, the network 100 may be an NR network deployed over a licensed spectrum. The BSs 105 may transmit synchronization signals (e.g., including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) ) in the network 100 to facilitate synchronization. The BSs 105 may broadcast system information associated with the network 100 (e.g., including a master information block (MIB) , remaining minimum system information (RMSI) , and other system information (OSI) ) to facilitate initial network access. In some instances, the BSs 105 may broadcast the PSS, the SSS, and/or the MIB in the form of synchronization signal blocks (SSBs) over a physical broadcast channel (PBCH) and may broadcast the RMSI and/or the OSI over a physical downlink shared channel (PDSCH) .

In some instances, a UE 115 attempting to access the network 100 may perform an initial cell search by detecting a PSS from a BS 105. The PSS may enable synchronization of period timing and may indicate a physical layer identity value. The UE 115 may then receive an SSS. The SSS may enable radio frame synchronization, and may provide a cell identity value, which may be combined with the physical layer identity value to identify the cell. The SSS may also enable detection of a duplexing mode and a cyclic prefix length. The PSS and the SSS may be located in a central portion of a carrier or any suitable frequencies within the carrier.

After receiving the PSS and SSS, the UE 115 may receive a MIB. The MIB may include system information for initial network access and scheduling information for RMSI and/or OSI. After decoding the MIB, the UE 115 may receive RMSI and/or OSI. The RMSI and/or OSI may include radio resource control (RRC) information related to random access channel (RACH) procedures, paging, control resource set (CORESET) for physical downlink control channel (PDCCH) monitoring, physical uplink control channel (PUCCH) , physical uplink shared channel (PUSCH) , power control, SRS, and cell barring.

After obtaining the MIB, the RMSI and/or the OSI, the UE 115 may perform a random access procedure to establish a connection with the BS 105. For the random access procedure, the UE 115 may transmit a random access preamble and the BS 105 may respond with a random access response. Upon receiving the random access response, the UE 115 may transmit a connection request to the BS 105 and the BS 105 may respond with a connection response (e.g., contention resolution message) .

After establishing a connection, the UE 115 and the BS 105 may enter a normal operation stage, where operational data may be exchanged. For example, the BS 105 may schedule the UE 115 for UL and/or DL communications. The BS 105 may transmit UL and/or DL scheduling grants to the UE 115 via a PDCCH. The BS 105 may transmit a DL communication signal to the UE 115 via a PDSCH according to a DL scheduling grant. The UE 115 may transmit a UL communication signal to the BS 105 via a PUSCH and/or PUCCH according to a UL scheduling grant.

The network 100 may be designed to enable a wide range of use cases. While in some examples a network 100 may utilize monolithic base stations, there are a number of other architectures which may be used to perform aspects of the present disclosure. For example, a BS 105 may be separated into a remote radio head (RRH) and baseband unit (BBU) . BBUs may be centralized into a BBU pool and connected to RRHs through low-latency and high-bandwidth transport links, such as optical transport links. BBU pools may be cloud-based resources. In some aspects, baseband processing is performed on virtualized servers running in data centers rather than being co-located with a BS 105. In another example, based station functionality may be split between a remote unit (RU) , distributed unit (DU) , and a central unit (CU) . An RU generally performs low physical layer functions while a DU performs higher layer functions, which may include higher physical layer functions. A CU performs the higher RAN functions, such as radio resource control (RRC) .

For simplicity of discussion, the present disclosure refers to methods of the present disclosure being performed by base stations, or more generally network entities, while the functionality may be performed by a variety of architectures other than a monolithic base station. In addition to disaggregated base stations, aspects of the present disclosure may also be performed by a centralized unit (CU) , a distributed unit (DU) , a radio unit (RU) , a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) , a Non-Real Time (Non-RT) RIC, integrated access and backhaul (IAB) node, a relay node, a sidelink node, etc.

In some aspects, the BS 105 may perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) . The BS 105 may transmit, to the UE 115 based on the first LBT procedure being successful, one or more TBs of the plurality of TBs. The BS 105 may perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

In some aspects, the UE 115 may perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) . The UE 115 may transmit, to the BS 105 based on the first LBT procedure being successful, one or more TBs of the plurality of TBs. The UE 115 may perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

In some aspects, a first UE 115 may perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) . The first UE 115 may transmit, to a second UE 115 based on the first LBT procedure being successful, one or more TBs of the plurality of TBs. The first UE 115 may perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

FIG. 2 shows a diagram illustrating an example disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that may communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both) . A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an F1 interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 115 via one or more radio frequency (RF) access links. In some implementations, the UE 115 may be simultaneously served by multiple RUs 240.

Each of the units, i.e., the CUs 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215 and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, may be configured to communicate with one or more of the other units via the transmission medium. For example, the units may include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units may include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver) , configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.

In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions may include radio resource control (RRC) , packet data convergence protocol (PDCP) , service data adaptation protocol (SDAP) , or the like. Each control function may be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (i.e., Central Unit –User Plane (CU-UP) ) , control plane functionality (i.e., Central Unit –Control Plane (CU-CP) ) , or a combination thereof. In some implementations, the CU 210 may be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 210 may be implemented to communicate with the DU 230, as necessary, for network control and signaling.

The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3^rd Generation Partnership Project (3GPP) . In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) may be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210.

Lower-layer functionality may be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like) , or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU (s) 240 may be implemented to handle over the air (OTA) communication with one or more UEs 115. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU (s) 240 may be controlled by the corresponding DU 230. In some scenarios, this configuration may enable the DU (s) 230 and the CU 210 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface) . For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface) . Such virtualized network elements may include CUs 210, DUs 230, RUs 240 and Near-RT RICs 225. In some implementations, the SMO Framework 205 may communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an O1 interface. Additionally, in some implementations, the SMO Framework 205 may communicate directly with one or more RUs 240 via an O1 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.

The Non-RT RIC 215 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence/Machine Learning (AI/ML) workflows including model training and updates, or policy-based guidance of applications/features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.

In some implementations, to generate AI/ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from non-network data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI/ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies) .

In some aspects, the RU 240 may perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) . The RU 240 may transmit, to the UE 115 based on the first LBT procedure being successful, one or more TBs of the plurality of TBs. The RU 240 may perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

In some aspects, the UE 115 may perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) . The UE 115 may transmit, to the RU 240 based on the first LBT procedure being successful, one or more TBs of the plurality of TBs. The UE 115 may perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

FIG. 3 illustrates survival time in wireless communications according to some aspects of the present disclosure. In FIG. 3, the vertical axis may represent time in some arbitrary units. In some aspects, a first wireless communication device 302a (e.g., the UE 115, the UE 800, the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) may perform a first listen-before-talk (LBT) procedure 306a in a shared frequency band. A category of the first LBT procedure 306a may be based on a first channel access priority class (CAPC) index value (e.g., a CAPC index value of 1, 2, 3, or 4) and/or energy detection threshold associated with a plurality of transport blocks (TBs) 304. In this regard, the first wireless communication device 302a may perform the LBT procedure with a sensing duration based on the CAPC index value and/or energy detection threshold associated with the plurality of TBs 304. The sensing duration may be a time period for performing a clear channel assessment (CCA) during which the first wireless communication device 302a senses the medium to determine whether the channel (e.g., the medium) is clear to transmit. For example, the first wireless communication device 302a may sense the channel for the sensing duration to determine if the channel is clear for the first wireless communication device 302a to transmit the plurality of TBs 304.

In some aspects, the first wireless communication device 302a may transmit one or more TBs 304a-304i of the plurality of TBs 304 to second wireless communication device 302b (e.g., the UE 115, the UE 800, the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) . The first wireless communication device 302a may transmit the one or more TBs 304a-304i by gaining access to the shared frequency band based on the first LBT procedure 306a being successful. In some aspects, the plurality of TBs 304 may be associated with an application (e.g., media streaming, V2X application, etc. ) running on the second wireless communication device 302b. The application may be served by data carried by the plurality of TBs 304 during application uptime 314. The second wireless communication device 302b may receive the TBs 304 and store the TBs 304 in a memory (e.g., memory 804, 904) buffer before being provided to the application. The second wireless communication device 302b may receive the TBs 304 during wireless communication uptime 308.

In some aspects, the first LBT 306b may be unsuccessful after transmitting the TB 304i thereby preventing the first wireless communication device 302a from gaining the channel and transmitting additional TB (s) 304. The first wireless communication device 302a may attempt subsequent LBT (s) based on the first CAPC index value and/or first energy threshold. The subsequent LBT (s) may also be unsuccessful thereby preventing further transmission of TBs resulting in wireless communication downtime 312. In some aspects, the application may continue to execute using the TB (s) 304 stored in the memory buffer until the buffer memory is empty. The time during which the second wireless communication device 302b no longer receives TB (s) but continues to execute the application using the TB (s) stored in the memory buffer may be referred to as survival time 310. Additionally or alternatively, the survival time 310 may be based on a timer that starts when the second wireless communication device 302b no longer receives TB (s) 304. In some aspects, an application layer of the first wireless communication device 302a may determine the survival time 310 and provide the survival time 310 to a physical layer of the first wireless communication device 302a. Additionally or alternatively, an application layer of the second wireless communication device 302b may determine the survival time 310 and provide the survival time 310 to a physical layer of the second wireless communication device 302b. When the second wireless communication device 302b no longer has TBs 304 to service the application at the end of survival time 310, the application may enter application downtime 316.

In some aspects, the first wireless communication device 302a may perform a second LBT procedure 306c. In some aspects, the at least one parameter of the second LBT procedure 306c may be based on a survival time 310 associated with the TBs 304 and/or a traffic priority associated with the TBs 304. In this regard, the parameter (s) of the second LBT procedure 306c may include a second CAPC index value (e.g., a CAPC index value of 1, 2, 3, or 4) . In some aspects, the first CAPC index value may be the same or different than the second CAPC index value. In some aspects, the second CAPC index value may be lower than the first CAPC index value and provide the second LBT procedure 306c with a higher probability of gaining access to the channel compared to the first LBT procedure 306a having a lower priority (e.g., a higher CAPC index value) . A higher probability of the first wireless communication device 302a gaining access to the channel may increase the probability of the second wireless communication device 302b receiving additional TBs 304 before expiration of the survival time 310. The first wireless communication device 302a may transmit one or more additional TB (s) 304j-304x of the plurality of TBs 304 to the second wireless communication device 302b based on the second LBT procedure 306c being successful. In some aspects, when the first wireless communication device 302a transmits one or more additional TB (s) 304j-304x of the plurality of TBs 304 to the second wireless communication device 302b based on the second LBT procedure 306c being successful, the second wireless communication device 302b may avoid entering application downtime 316 and re-enter application uptime 314 and wireless communication uptime 308.

In some aspects, the first wireless communication device 302a may include a UE (e.g., the UE 115, the UE 800) and the second wireless communication device 302b may include a network unit (e.g., the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) . Additionally or alternatively, the first wireless communication device 302a may include a network unit (e.g., the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) and the second wireless communication device 302b may include a UE (e.g., the UE 115, the UE 800) . Additionally or alternatively, the first wireless communication device 302a may include first UE (e.g., the UE 115, the UE 800) and the second wireless communication device 302b may include a second UE (e.g., the UE 115, the UE 800) .

FIG. 4 illustrates LBT procedures during survival time in wireless communications according to some aspects of the present disclosure. In FIG. 4, the horizontal axis may represent time in some arbitrary units. In some aspects, a first wireless communication device may perform a first LBT procedure with first LBT parameters 402 in a shared frequency band. The first LBT parameters 402 may include a first CAPC index value (e.g., a CAPC index value of 1, 2, 3, or 4) and/or an energy detection threshold. In this regard, the first wireless communication device may perform the LBT procedure with a sensing duration based on first LBT parameters 402 during wireless communication uptime 308. At time T2, the first wireless communication device may perform the LBT procedure with second parameters 404 based on entering wireless communication downtime 312. The first wireless communication device may perform the LBT procedure with second parameters 404 as soon as wireless communication downtime is detected (e.g., a failed LBT procedure) . When the first wireless communication device performs a successful LBT with second parameters 404, the first wireless communication device may reenter wireless communication uptime 308 and continue to transmit TBs to the second wireless communication device. At time T3, the wireless communication device may revert back to performing LBT (s) with the first parameters.

In some aspects, the LBT procedure with second parameters 404 may be based on a survival time associated with the one or more TBs and/or a traffic priority associated with the one or more TBs. In this regard, the parameter (s) of the second LBT procedure may include a second CAPC index value (e.g., a CAPC index value of 1, 2, 3, or 4) . In some aspects, the first CAPC index value may be the same or different than the second CAPC index value. In some aspects, the second CAPC index value may be lower than the first CAPC index value and provide the second LBT procedure with a higher probability of gaining access to the channel compared to the first LBT procedure having a lower priority (e.g., a higher CAPC index value) . A higher probability of the first wireless communication device gaining access to the channel may increase the probability of the second wireless communication device receiving additional TBs before expiration of the survival time. The first wireless communication device may transmit one or more additional TB (s) of the plurality of TBs to the second wireless communication device based on the second LBT procedure being successful during the survival time.

In some aspects, the second CAPC index value may be based on a remaining time duration within the survival time satisfying a threshold. For example, the second CAPC index value may be based on a remaining time duration within the survival time being less than or equal to the threshold. In some aspects, the first wireless communication device may select a higher second CAPC index value for a longer remaining time duration within the survival time and select a lower second CAPC index value for a shorter remaining time duration within the survival time. In some aspects, the threshold may be represented as a percentage of remaining time within the survival time. Additionally or alternatively, the threshold may be represented as a time period (e.g. a number of milliseconds) , a number of slots, a number of subframes, and/or a number of radio frames. In some aspects, a different threshold value may correspond to each of the CAPC index values.

In some aspects, the second CAPC index value may be based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the second CAPC index value may be based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time being less than or equal to the threshold. In some aspects, the threshold may be represented as a number of TBs to be transmitted. Additionally or alternatively, the threshold may be represented as a number of PDSCH communications, PUSCH communications, and/or PSSCH transmissions carrying the TBs.

In some aspects, the second CAPC index value may be based on a remaining number of TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold. For example, the second CAPC index value may be based on a remaining number of TBs of the plurality of TBs scheduled to be retransmitted within the survival time being less than or equal to the threshold. For example, when the first wireless communication device selects a first CAPC index value of 4 (e.g., a CAPC index value of 4 based on a QOS associated with the TB) for the first LBT procedure (e.g., the failed LBT) and the number of allowed retransmissions is one, the first wireless communication device may contend for the channel again using a lower CAPC index value (e.g., a second CAPC value of 1, 2, or 3) . In this manner, the first wireless communication device may have a higher probability of gaining access to the channel using the second LBT with a lower CAPC index value to retransmit the TB as compared to the first LBT procedure with a higher CAPC index value.

Additionally or alternatively, the second parameter (s) of the second LBT procedure 404 may include an energy detection threshold associated with the second LBT procedure. The first wireless communication device may sense the channel and determine that the LBT procedure is successful if the energy detected in the channel is less than the energy detection threshold. In some aspects, the energy detection threshold associated with the first LBT procedure may be the same or different than the energy detection threshold associated with the second LBT procedure. In some aspects, the energy detection threshold associated with the second LBT procedure may be higher than the energy detection threshold associated with the first LBT procedure and provide the second LBT procedure with a higher probability of gaining access to the channel compared to the first LBT procedure. A higher probability of the first wireless communication device gaining access to the channel may increase the probability of the second wireless communication device to receive additional TBs before expiration of the survival time. The first wireless communication device may transmit one or more additional TB (s) of the plurality of TBs to the second wireless communication device based on the second LBT procedure being successful during the survival time.

In some aspects, the energy detection threshold may be based on a remaining time duration within the survival time satisfying a survival time threshold. For example, the energy detection threshold may be based on a remaining time duration within the survival time being less than or equal to the survival time threshold. In some aspects, the first wireless communication device may select a lower energy detection threshold for a longer remaining time duration within the survival time and select a higher energy detection threshold for a shorter remaining time duration within the survival time. In some aspects, the survival time threshold may be represented as a percentage of remaining time within the survival time. Additionally or alternatively, the survival time threshold may be represented as a time period (e.g. a number of milliseconds) and/or a number of slots, a number of subframes, and/or a number of radio frames. In some aspects, a different survival time threshold value may correspond to a different energy detection threshold.

In some aspects, the energy detection threshold may be based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the energy detection threshold may be based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time being less than or equal to the remaining number of TBs threshold. In some aspects, the remaining number of TBs threshold may be represented as a number of TBs. Additionally or alternatively, the remaining number of TBs threshold may be represented as a number of PDSCH communications, PUSCH communications, and/or PSSCH transmissions carrying the TBs.

In some aspects, the energy detection threshold may be based on a remaining number of TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold. For example, the energy detection threshold may be based on a remaining number of TBs of the plurality of TBs scheduled to be retransmitted within the survival time being less than or equal to the remaining number of TBs to be retransmitted threshold. The first wireless communication device may have a higher probability of gaining access to the channel using the second LBT with a higher energy detection threshold to retransmit the TB as compared to the first LBT procedure with a lower energy detection threshold.

In some aspects, the first wireless communication device may select the parameter (s) associated with the second LBT procedure to have a higher priority than the parameter (s) associated with the first LBT procedure. For example, the first wireless communication device may select the CAPC index value associated with the second LBT procedure to be less than or equal to the CAPC index value associated with the first LBT procedure. Additionally or alternatively, the first wireless communication device may select the energy detection threshold associated with the second LBT procedure to be greater than or equal to the energy detection threshold associated with the first LBT procedure.

In some aspects, the first wireless communication device may use the second LBT procedure to gain access to the channel upon entering the survival time as indicated by T2 in FIG. 4.

FIG. 5 illustrates LBT procedures during survival time in wireless communications according to some aspects of the present disclosure. In FIG. 5, the horizontal axis may represent time in some arbitrary units. FIG. 4 illustrates the first wireless communication device performing the LBT with the second parameters upon (e.g., immediately upon) entering the wireless communication downtime 312. FIG. 5 illustrates the aspects of FIG. 4 with the first wireless communication device waiting a period of time after entering wireless communication downtime 312 to perform the LBT with the second parameters 404. In this regard, the first wireless communication device may wait a threshold period of time after entering wireless communication downtime 312. For example, the first wireless communication device may wait until survival time threshold 502 before performing the LBT with the second parameters. The survival time threshold 502 may be based on a length of the survival time and/or a priority level associated with the TB (s) to be transmitted by the first wireless communication device.

FIG. 6 is a flow diagram of a communication method 600 according to some aspects of the present disclosure. Aspects of the method 600 may be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device or other suitable means for performing the actions. For example, a wireless communication device, such as the UE 115 or the UE 800 may utilize one or more components, such as the processor 802, the memory 804, the survival time module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to execute aspects of method 600. The method 600 may employ similar mechanisms as in the networks 100 and 200 and the aspects and actions described with respect to FIGs. 3-5. For example, a wireless communication device, such as the network unit 105 may utilize one or more components, such as the processor 902, the memory 904, the survival time module 908, the transceiver 910, the modem 912, and the one or more antennas 916, to execute aspects of method 600. As illustrated, the method 600 includes a number of enumerated actions, but the method 600 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

At action 602, the first wireless communication device 302a may perform a successful first LBT based on first parameters. The first parameters may include a CAPC index value and/or an energy detection threshold. In some aspects, the parameters may be based on a priority associated with TBs to be transmitted to the second wireless communication device 302b.

At action 604, the first wireless communication device 302a may transmit one or more TBs to the second wireless communication device 302b based on the LBT at action 602 being successful. The TBs may be associated with an application having a survival time requirement.

At action 608, the first wireless communication device 302a may perform an unsuccessful LBT based on the first parameters (e.g., a first CAPC index value and/or a first energy detection threshold) . The unsuccessful LBT may prevent the first wireless communication device 302a from gaining access to the channel and transmitting additional TB (s) .

At action 610, the second wireless communication device 302b may enter survival time based on the unsuccessful LBT at action 608 preventing the first wireless communication device 302a from gaining access to the channel and transmitting additional TB (s) . During the survival time, the second wireless communication device 302b may continue to execute the application based on previously received (e.g., stored) TBs.

At action 612, the first wireless communication device 302a may determine second parameters for performing an LBT. The first wireless communication device 302a may determine second LBT parameters (e.g., a second CAPC index value and/or a second energy detection threshold) that may increase the probability of the first wireless communication device 302a gaining access to the channel in order to continue transmitting TBs to the second wireless communication device 302b. For example, the first wireless communication device 302a may determine a second CAPC index value that is lower than the first CAPC index value. Additionally or alternatively, the first wireless communication device 302a may determine a second energy detection threshold that is higher than the first energy detection threshold.

At action 614, the first wireless communication device 302a may perform a successful second LBT based on second parameters. The successful LBT based on the second parameters may allow the first wireless communication device 302a to regain the channel.

At action 616, the first wireless communication device 302a may transmit one or more additional TB (s) to the second wireless communication device 302b based on the LBT performed with the second parameters at action 614 being successful.

FIG. 7 is a flow diagram of a communication method 700 according to some aspects of the present disclosure. Aspects of the method 700 may be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device or other suitable means for performing the actions. For example, a wireless communication device, such as the UE 115 or the UE 800 may utilize one or more components, such as the processor 802, the memory 804, the survival time module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to execute aspects of method 700. The method 700 may employ similar mechanisms as in the networks 100 and 200 and the aspects and actions described with respect to FIGs. 3-5. For example, a wireless communication device, such as the network unit 105 may utilize one or more components, such as the processor 902, the memory 904, the survival time module 908, the transceiver 910, the modem 912, and the one or more antennas 916, to execute aspects of method 700. As illustrated, the method 700 includes a number of enumerated actions, but the method 700 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

At action 702, the first wireless communication device 302a may transmit an indicator indicating a survival time requirement associated with a plurality of TBs to the second wireless communication device 302b. In this regard, the first wireless communication device 302a may transmit the indicator via at least one of downlink control information (DCI) , sidelink control information (SCI) , a physical downlink control channel (PDCCH) communication, a physical uplink control channel (PUCCH) communication, a physical sidelink control channel (PSCCH) communication, a physical sidelink feedback channel (PSFCH) communication, a radio resource control (RRC) message, and/or other suitable communication. The indicator may indicate a survival time requirement for an application running on the second wireless communication device 302b. In some aspects, the plurality of TBs may be associated with an application that uses survival time. The survival time may be a time period for which the application may tolerate failures in the transmission of TBs (e.g., resulting from failed LBT procedure (s) ) . In some aspects, the first wireless communication device 302a may transmit the indicator during an initial connection (e.g., upon entering RRC connected mode) with the second wireless communication device 302b and/or at the start of the application.

At action 704, the first wireless communication device 302a may perform a successful first LBT in a shared frequency band. In this regard, the first wireless communication device may perform the LBT procedure using parameters based on a priority associated with the TBs.

At action 706, the first wireless communication device 302a may transmit one or more TBs to the second wireless communication device 302b based on the LBT at action 704 being successful. The TBs may be associated with the application having the survival time requirement.

At action 710, the first wireless communication device 302a may perform an unsuccessful LBT. The unsuccessful LBT may prevent the first wireless communication device 302a from gaining access to the channel and transmitting additional TB (s) .

At action 712, the second wireless communication device 302b may enter survival time based on the unsuccessful LBT at action 710 preventing the first wireless communication device 302a from gaining access to the channel and transmitting additional TB (s) . During the survival time, the second wireless communication device 302b may continue to execute the application based on previously received TB (s) .

At action 714, the first wireless communication device 302a may perform a successful LBT based on parameters different from the unsuccessful LBT at action 710. For the example, the first wireless communication device 302a may perform a category 2 LBT procedure to gain access to the channel.

At action 716, the first wireless communication device 302a may transmit a channel occupancy time (COT) sharing request to the second wireless communication device 302b based on the LBT procedure at action 714 being successful. In this regard, the first wireless communication device 302a may transmit the COT sharing request via at least one of downlink control information (DCI) , sidelink control information (SCI) , a physical downlink control channel (PDCCH) communication, a physical uplink control channel (PUCCH) communication, a physical sidelink control channel (PSCCH) communication, a physical sidelink feedback channel (PSFCH) communication, a radio resource control (RRC) message and/or other suitable communication.

In some aspects, the first wireless communication device 302a may transmit the COT sharing request upon entering the survival time at action 712. Additionally or alternatively, the first wireless communication device 302a may transmit the COT sharing request after waiting a period of time after entering the survival time. For example, the first wireless communication device 302a may wait a period of time based on a timer, a QOS associated with the plurality of TBs, a priority associated with the plurality of TBs, or other suitable parameter.

In some aspects, the first wireless communication device 302a may transmit the COT sharing request using resources (e.g., time resources and/or frequency resources) using a physical sidelink feedback channel (PSFCH) resource pool. Additionally or alternatively, the first wireless communication device 302a may transmit the COT sharing request using resources (e.g., time resources and/or frequency resources) using a COT sharing request resource pool. In some aspects, the resources of the PSFCH resource pool may partially overlap the resources of the COT sharing request resource pool.

In some aspects, the first wireless communication device 302a may transmit the COT sharing request via a unicast message to the second wireless communication device 302b. Additionally or alternatively, the first wireless communication device 302a may transmit the COT sharing request via a groupcast message to the second wireless communication device 302b and/or a group of additional wireless communication devices. In this manner, the first wireless communication device 302a may share the COT with the second wireless communication device 302b and/or an additional wireless communication device (s) included in the groupcast communication.

In some aspects, the first wireless communication device 302a may transmit the COT sharing request during the survival time in order to gain a shared COT and continue to transmit additional TBs of the plurality of TBs to the second wireless communication device 302b. In some aspects, the first wireless communication device 302a may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the COT sharing request may be transmitted based on a remaining time duration within the survival time being less than or equal to the threshold. In some aspects, the threshold may be represented as a percentage of remaining time within the survival time. Additionally or alternatively, the threshold may be represented as a time period (e.g. a number of milliseconds) , a number of slots, a number of subframes, and/or a number of radio frames.

In some aspects, the first wireless communication device 302a may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the first wireless communication device 302a may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time being less than or equal to the threshold. In some aspects, the threshold may be represented as a number of TB (s) . Additionally or alternatively, the threshold may be represented as a number of PDSCH communications, PUSCH communications, and/or PSSCH transmissions carrying the TB (s) .

In some aspects, the first wireless communication device 302a may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold. For example, the first wireless communication device 302a may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time being less than or equal to the threshold.

At action 718, the first wireless communication device 302a may receive an indicator to share the COT from the second wireless communication device 302b and/or another wireless communication device. In this regard, the first wireless communication device 302a may receive the COT sharing indicator via at least one of downlink control information (DCI) , sidelink control information (SCI) , a physical downlink control channel (PDCCH) communication, a physical uplink control channel (PUCCH) communication, a physical sidelink control channel (PSCCH) communication, a physical sidelink feedback channel (PSFCH) communication, a radio resource control (RRC) message and/or other suitable communication. Additionally or alternatively, the first wireless communication device 302a may receive the indicator to share the COT from a wireless communication device other than the second wireless communication device 302b. For example, the first wireless communication device 302a may receive the indicator to share the COT from a wireless communication device that received the COT sharing request in the groupcast message at action 716.

At action 720, the first wireless communication device 302a may transmit additional TB (s) to the second wireless communication device 302b based on the COT sharing indication received at action 718. In this regard, the first wireless communication device 302a may transmit the additional TB (s) during the COT via a PDSCH communication, a PUSCH communication, a PSSCH communication, and/or other suitable communication. In some aspects, the COT may at least partially overlap the survival time.

FIG. 8 is a block diagram of an exemplary UE 800 according to some aspects of the present disclosure. The UE 800 may be the UE 115 in the network 100, or 200 as discussed above. As shown, the UE 800 may include a processor 802, a memory 804, a survival time module 808, a transceiver 810 including a modem subsystem 812 and a radio frequency (RF) unit 814, and one or more antennas 816. These elements may be coupled with each other and in direct or indirect communication with each other, for example via one or more buses.

The processor 802 may include a central processing unit (CPU) , a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 802 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The memory 804 may include a cache memory (e.g., a cache memory of the processor 802) , random access memory (RAM) , magnetoresistive RAM (MRAM) , read-only memory (ROM) , programmable read-only memory (PROM) , erasable programmable read only memory (EPROM) , electrically erasable programmable read only memory (EEPROM) , flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some instances, the memory 804 includes a non-transitory computer-readable medium. The memory 804 may store instructions 806. The instructions 806 may include instructions that, when executed by the processor 802, cause the processor 802 to perform the operations described herein with reference to the UEs 115 in connection with aspects of the present disclosure, for example, aspects of FIGS. 3-7. Instructions 806 may also be referred to as code. The terms “instructions” and “code” should be interpreted broadly to include any type of computer-readable statement (s) . For example, the terms “instructions” and “code” may refer to one or more programs, routines, sub-routines, functions, procedures, etc. “Instructions” and “code” may include a single computer-readable statement or many computer-readable statements.

The survival time module 808 may be implemented via hardware, software, or combinations thereof. For example, the survival time module 808 may be implemented as a processor, circuit, and/or instructions 806 stored in the memory 804 and executed by the processor 802. In some aspects, the survival time module 808 may implement the aspects of FIGS. 3-7. For example, the survival time module 808 may perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) . The survival time module 808 may transmit, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs. The survival time module 808 may perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

As shown, the transceiver 810 may include the modem subsystem 812 and the RF unit 814. The transceiver 810 may be configured to communicate bi-directionally with other devices, such as the BSs 105 and/or the UEs 115. The modem subsystem 812 may be configured to modulate and/or encode the data from the memory 804 and the according to a modulation and coding scheme (MCS) , e.g., a low-density parity check (LDPC) coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 814 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data from the modem subsystem 812 (on outbound transmissions) or of transmissions originating from another source such as a UE 115 or a BS 105. The RF unit 814 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 810, the modem subsystem 812 and the RF unit 814 may be separate devices that are coupled together to enable the UE 800 to communicate with other devices.

The RF unit 814 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 816 for transmission to one or more other devices. The antennas 816 may further receive data messages transmitted from other devices. The antennas 816 may provide the received data messages for processing and/or demodulation at the transceiver 810. The antennas 816 may include multiple antennas of similar or different designs in order to sustain multiple transmission links. The RF unit 814 may configure the antennas 816.

In some instances, the UE 800 may include multiple transceivers 810 implementing different RATs (e.g., NR and LTE) . In some instances, the UE 800 may include a single transceiver 810 implementing multiple RATs (e.g., NR and LTE) . In some instances, the transceiver 810 may include various components, where different combinations of components may implement RATs.

FIG. 9 is a block diagram of an exemplary network unit 900 according to some aspects of the present disclosure. The network unit 900 may be the BS 105, the CU 210, the DU 230, or the RU 240, as discussed above. As shown, the network unit 900 may include a processor 902, a memory 904, a survival time module 908, a transceiver 910 including a modem subsystem 912 and a RF unit 914, and one or more antennas 916. These elements may be coupled with each other and in direct or indirect communication with each other, for example via one or more buses.

The processor 902 may have various features as a specific-type processor. For example, these may include a CPU, a DSP, an ASIC, a controller, a FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. The processor 902 may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The memory 904 may include a cache memory (e.g., a cache memory of the processor 902) , RAM, MRAM, ROM, PROM, EPROM, EEPROM, flash memory, a solid state memory device, one or more hard disk drives, memristor-based arrays, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some instances, the memory 904 may include a non-transitory computer-readable medium. The memory 904 may store instructions 906. The instructions 906 may include instructions that, when executed by the processor 902, cause the processor 902 to perform operations described herein, for example, aspects of FIGS. 3-7. Instructions 906 may also be referred to as code, which may be interpreted broadly to include any type of computer-readable statement (s) .

The survival time module 908 may be implemented via hardware, software, or combinations thereof. For example, the survival time module 908 may be implemented as a processor, circuit, and/or instructions 906 stored in the memory 904 and executed by the processor 902.

In some aspects, the survival time module 908 may implement the aspects of FIGS. 3-7. For example, the survival time module 908 may perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) . The survival time module 908 may transmit, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs. The survival time module 908 may perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

Additionally or alternatively, the survival time module 908 may be implemented in any combination of hardware and software, and may, in some implementations, involve, for example, processor 902, memory 904, instructions 906, transceiver 910, and/or modem 912.

As shown, the transceiver 910 may include the modem subsystem 912 and the RF unit 914. The transceiver 910 may be configured to communicate bi-directionally with other devices, such as the UEs 115 and/or UE 800. The modem subsystem 912 may be configured to modulate and/or encode data according to a MCS, e.g., a LDPC coding scheme, a turbo coding scheme, a convolutional coding scheme, a digital beamforming scheme, etc. The RF unit 914 may be configured to process (e.g., perform analog to digital conversion or digital to analog conversion, etc. ) modulated/encoded data from the modem subsystem 912 (on outbound transmissions) or of transmissions originating from another source such as a UE 115 or UE 800. The RF unit 914 may be further configured to perform analog beamforming in conjunction with the digital beamforming. Although shown as integrated together in transceiver 910, the modem subsystem 912 and/or the RF unit 914 may be separate devices that are coupled together at the network unit 900 to enable the network unit 900 to communicate with other devices.

The RF unit 914 may provide the modulated and/or processed data, e.g. data packets (or, more generally, data messages that may contain one or more data packets and other information) , to the antennas 916 for transmission to one or more other devices. This may include, for example, a configuration indicating a plurality of sub-slots within a slot according to aspects of the present disclosure. The antennas 916 may further receive data messages transmitted from other devices and provide the received data messages for processing and/or demodulation at the transceiver 910. The antennas 916 may include multiple antennas of similar or different designs in order to sustain multiple transmission links.

In some instances, the network unit 900 may include multiple transceivers 910 implementing different RATs (e.g., NR and LTE) . In some instances, the network unit 900 may include a single transceiver 910 implementing multiple RATs (e.g., NR and LTE) . In some instances, the transceiver 910 may include various components, where different combinations of components may implement RATs.

FIG. 10 is a flow diagram of a communication method 1000 according to some aspects of the present disclosure. Aspects of the method 1000 can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device or other suitable means for performing the actions. For example, a wireless communication device, such as the UE 115 or the UE 800, may utilize one or more components, such as the processor 802, the memory 804, the survival time module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to execute aspects of method 1000. For example, a wireless communication device, such as the network unit (e.g., the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) may utilize one or more components, such as the processor 902, the memory 904, the survival time module 908, the transceiver 910, the modem 912, and the one or more antennas 916, to execute aspects of method 1000. The method 1000 may employ similar mechanisms as in the networks 100 and 200 and the aspects and actions described with respect to FIGS. 3-7. As illustrated, the method 1000 includes a number of enumerated actions, but the method 1000 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

At action 1010, the method 1000 includes a first wireless communication device (e.g., the UE 115, the UE 800, the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) performing a first listen-before-talk (LBT) procedure in a shared frequency band. A category of the first LBT procedure may be based on a first channel access priority class (CAPC) index value (e.g., a CAPC index value of 1, 2, 3, or 4) associated with a plurality of transport blocks (TBs) . In this regard, the first wireless communication device may perform the LBT procedure with a sensing duration based on the CAPC index value associated with the plurality of TBs. The sensing duration may be a time period for performing a clear channel assessment (CCA) during which the first wireless communication device senses the medium to determine whether the channel (e.g., the medium) is clear to transmit. For example, the first wireless communication device may sense the channel for the sensing duration to determine if the channel is clear for the first wireless communication device to transmit the plurality of TBs.

At action 1020, the method 1000 includes the first wireless communication device transmitting one or more TBs of the plurality of TBs to a second wireless communication device (e.g., the UE 115, the UE 800, the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) . The first wireless communication device may transmit the one or more TBs by gaining access to the shared frequency band based on the first LBT procedure being successful. In some aspects, the plurality of TBs may be associated with an application (e.g., media streaming, V2X applications, etc. ) running on the second wireless communication device. The application may be served by data carried in the plurality of TBs. The second wireless communication device may receive the TB (s) and store the TB (s) in a memory (e.g., memory 804, 904) buffer before being provided to the application.

In some aspects, the first LBT may be unsuccessful thereby preventing the first wireless communication device from gaining the channel and transmitting the one or more TBs. The first wireless communication device may attempt subsequent LBT (s) based on the first CAPC index value. The subsequent LBT (s) may also be unsuccessful thereby preventing further transmission of TB (s) . In some aspects, the application may continue to execute using the TB (s) stored in the memory buffer until the buffer memory is empty. The time during which the second wireless communication device no longer receives TB (s) but continues to execute the application using the TB (s) stored in the memory buffer may be referred to as survival time. Additionally or alternatively, the survival time may be based on a timer that starts when the second wireless communication device no longer receives TB (s) . In some aspects, an application layer of the first wireless communication device may determine the survival time and provide the survival time to a physical layer of the first wireless communication device. Additionally or alternatively, an application layer of the second wireless communication device may determine the survival time and provide the survival time to a physical layer of the second wireless communication device.

At action 1030, the method 1000 includes the first wireless communication device performing a second LBT procedure. In some aspects, the at least one parameter of the second LBT procedure may be based on a survival time associated with the one or more TBs and/or a traffic priority associated with the one or more TBs. In this regard, the parameter (s) of the second LBT procedure may include a second CAPC index value (e.g., a CAPC index value of 1, 2, 3, or 4) . In some aspects, the first CAPC index value may be the same or different than the first CAPC value. In some aspects, the second CAPC index value may be lower than the first CAPC index value and provide the second LBT procedure with a higher probability of gaining access to the channel compared to the first LBT procedure having a lower priority (e.g., a higher CAPC index value) . A higher probability of the first wireless communication device gaining access to the channel may increase the probability of the second wireless communication device receiving additional TB (s) before expiration of the survival time. The first wireless communication device may transmit one or more additional TB (s) of the plurality of TBs to the second wireless communication device based on the second LBT procedure being successful during the survival time.

In some aspects, the first wireless communication device may include a UE and the second wireless communication device may include a network unit. Additionally or alternatively, the first wireless communication device may include a network unit and the second wireless communication device may include a UE. Additionally or alternatively, the first wireless communication device may include first UE and the second wireless communication device may include a second UE.

In some aspects, the second CAPC index value may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the second CAPC index value may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time being less than or equal to the threshold. In some aspects, the threshold may be represented as a number of TB (s) to be transmitted. Additionally or alternatively, the threshold may be represented as a number of PDSCH communications, PUSCH communications, and/or PSSCH transmissions carrying the TB (s) .

In some aspects, the second CAPC index value may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold. For example, the second CAPC index value may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time being less than or equal to the threshold. For example, when the first wireless communication device selects a first CAPC index value of 4 (e.g., a CAPC index value of 4 based on a QOS associated with the TB) for the first LBT procedure (e.g., the failed LBT) and the number of allowed retransmissions is one, the first wireless communication device may contend for the channel again using a lower CAPC index value (e.g., a second CAPC value of 1, 2, or 3) . In this manner, the first wireless communication device may have a higher probability of gaining access to the channel using the second LBT with a lower CAPC index value to retransmit the TB as compared to the first LBT procedure with a higher CAPC index value.

Additionally or alternatively, the parameter (s) of the second LBT procedure may include an energy detection threshold associated with the second LBT procedure. The first wireless communication device may sense the channel and determine that the LBT procedure is successful if the energy detected in the channel is less than the energy detection threshold. In some aspects, the energy detection threshold associated with the first LBT procedure may be the same or different than the energy detection threshold associated with the second LBT procedure. In some aspects, the energy detection threshold associated with the second LBT procedure may be lower than the energy detection threshold associated with the first LBT procedure and provide the second LBT procedure with a higher probability of gaining access to the channel compared to the first LBT procedure. A higher probability of the first wireless communication device gaining access to the channel may increase the probability of the second wireless communication device to receive additional TB (s) before expiration of the survival time. The first wireless communication device may transmit one or more additional TB (s) of the plurality of TBs to the second wireless communication device based on the second LBT procedure being successful during the survival time.

In some aspects, the energy detection threshold may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the energy detection threshold may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time being less than or equal to the remaining number of TB (s) threshold. In some aspects, the remaining number of TB (s) threshold may be represented as a number of TB (s) . Additionally or alternatively, the remaining number of TB (s) threshold may be represented as a number of PDSCH communications, PUSCH communications, and/or PSSCH transmissions carrying the TB (s) .

In some aspects, the energy detection threshold may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold. For example, the energy detection threshold may be based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time being less than or equal to the remaining number of TB (s) to be retransmitted threshold. The first wireless communication device may have a higher probability of gaining access to the channel using the second LBT with a lower energy detection threshold to retransmit the TB as compared to the first LBT procedure with a higher energy detection threshold.

In some aspects, the first wireless communication device may use the second LBT procedure to gain access to the channel upon entering the survival time. Additionally or alternatively, the first wireless communication device may use the second LBT procedure to gain access to the channel after waiting a period of time after entering the survival time. For example, the first wireless communication device may wait a period of time based on a timer, a QOS associated with the plurality of TBs, a priority associated with the plurality of TBs, or other suitable parameter.

FIG. 11 is a flow diagram of a communication method 1100 according to some aspects of the present disclosure. Aspects of the method 1100 can be executed by a computing device (e.g., a processor, processing circuit, and/or other suitable component) of a wireless communication device or other suitable means for performing the actions. For example, a wireless communication device, such as the UE 115 or the UE 800, may utilize one or more components, such as the processor 802, the memory 804, the survival time module 808, the transceiver 810, the modem 812, and the one or more antennas 816, to execute aspects of method 1100. For example, a wireless communication device, such as the network unit (e.g., the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) may utilize one or more components, such as the processor 902, the memory 904, the survival time module 908, the transceiver 910, the modem 912, and the one or more antennas 916, to execute aspects of method 1100. The method 1100 may employ similar mechanisms as in the networks 100 and 200 and the aspects and actions described with respect to FIGS. 3-7. As illustrated, the method 1100 includes a number of enumerated actions, but the method 1100 may include additional actions before, after, and in between the enumerated actions. In some aspects, one or more of the enumerated actions may be omitted or performed in a different order.

At action 1110, the method 1100 includes a first wireless communication device (e.g., the UE 115, the UE 800, the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) transmitting an indicator to a second wireless communication device (e.g., the UE 115, the UE 800, the network unit 900, the BS 105, the RU 240, the DU 230, and/or the CU 210) indicating a survival time associated with a plurality of TBs. In this regard, the first wireless communication device may transmit an indicator via at least one of downlink control information (DCI) , sidelink control information (SCI) , a physical downlink control channel (PDCCH) communication, a physical uplink control channel (PUCCH) communication, a physical sidelink control channel (PSCCH) communication, a physical sidelink feedback channel (PSFCH) communication, a radio resource control (RRC) message, and/or other suitable communication.

In some aspects, the plurality of TBs may be associated with an application that uses survival time. The survival time may be a time period for which the application may tolerate failures in the transmission of TB (s) (e.g., failed LBT procedure (s) ) . In some aspects, the first wireless communication device may transmit the indicator during an initial connection (e.g., upon entering RRC connected mode) with the second wireless communication device and/or at the start of the application.

At action 1120, the method 1100 includes the first wireless communication device performing a listen-before-talk (LBT) procedure in a shared frequency band. In this regard, the first wireless communication device may perform a category 2 LBT procedure to gain access to the channel.

At action 1130, the method 1100 includes the first wireless communication device transmitting a channel occupancy time (COT) sharing request to the second wireless communication device based on the LBT procedure at action 1120 being successful. In this regard, the first wireless communication device may transmit the COT sharing request via at least one of downlink control information (DCI) , sidelink control information (SCI) , a physical downlink control channel (PDCCH) communication, a physical uplink control channel (PUCCH) communication, a physical sidelink control channel (PSCCH) communication, a physical sidelink feedback channel (PSFCH) communication, a radio resource control (RRC) message and/or other suitable communication.

In some aspects, the first wireless communication device may transmit the COT sharing request upon entering the survival time. Additionally or alternatively, the first wireless communication device may transmit the COT sharing request after waiting a period of time after entering the survival time. For example, the first wireless communication device may wait a period of time based on a timer, a QOS associated with the plurality of TBs, a priority associated with the plurality of TBs, or other suitable parameter.

In some aspects, the first wireless communication device may transmit the COT sharing request using resources (e.g., time resources and/or frequency resources) using a physical sidelink feedback channel (PSFCH) resource pool. Additionally or alternatively, the first wireless communication device may transmit the COT sharing request using resources (e.g., time resources and/or frequency resources) using a COT sharing request resource pool. In some aspects, the resources of the PSFCH resource pool may partially overlap the resources of the COT sharing request resource pool.

In some aspects, the first wireless communication device may transmit the COT sharing request via a unicast message to the second wireless communication device. Additionally or alternatively, the first wireless communication device may transmit the COT sharing request via a groupcast message to the second wireless communication device and a group of additional wireless communication devices. In this manner, the first wireless communication device may share the COT with the second wireless communication device and/or an additional wireless communication device included in the groupcast communication.

In some aspects, the first wireless communication device may transmit the COT sharing request during the survival time in order to gain a shared COT and continue to transmit one or more TBs of the plurality of TBs to the second wireless communication device. In some aspects, the first wireless communication device may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the COT sharing request may be transmitted based on a remaining time duration within the survival time being less than or equal to the threshold. In some aspects, the threshold may be represented as a percentage of remaining time within the survival time. Additionally or alternatively, the threshold may be represented as a time period (e.g. a number of milliseconds) , a number of slots, a number of subframes, and/or a number of radio frames.

In some aspects, the first wireless communication device may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold. For example, the first wireless communication device may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time being less than or equal to the threshold. In some aspects, the threshold may be represented as a number of TB (s) . Additionally or alternatively, the threshold may be represented as a number of PDSCH communications, PUSCH communications, and/or PSSCH transmissions carrying the TB (s) .

In some aspects, the first wireless communication device may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold. For example, the first wireless communication device may transmit the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be retransmitted within the survival time being less than or equal to the threshold.

At action 1140, the method 1100 includes the first wireless communication device receiving an indicator to share the COT from the second wireless communication device. In this regard, the first wireless communication device may receive the COT sharing indicator via at least one of downlink control information (DCI) , sidelink control information (SCI) , a physical downlink control channel (PDCCH) communication, a physical uplink control channel (PUCCH) communication, a physical sidelink control channel (PSCCH) communication, a physical sidelink feedback channel (PSFCH) communication, a radio resource control (RRC) message and/or other suitable communication. Additionally or alternatively, the first wireless communication device may receive the indicator to share the COT from a wireless communication device other than the second wireless communication device. For example, the first wireless communication device may receive the indicator to share the COT from a wireless communication device that received the COT sharing request in the groupcast message at action 1130.

At action 1150, the method 1100 includes the first wireless communication device transmitting one or more TBs of the plurality of TBs to the second wireless communication device. In this regard, the first wireless communication device may transmit the one or more TBs during the COT via a PDSCH communication, a PUSCH communication, a PSSCH communication, and/or other suitable communication. In some aspects, the COT may at least partially overlap the survival time.

Further aspects of the present disclosure include the following:

Aspect 1 includes a method of wireless communication performed by a first wireless communication device, the method comprising performing a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) ; and transmitting, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs; and performing a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.

Aspect 2 includes the method of aspect 1, wherein the survival time is based on a maximum number of consecutive TBs of the plurality of TBs not transmitted based on the first LBT procedure being unsuccessful.

Aspect 3 includes the method of any of aspects 1-2, further comprising determining, by an application layer of the first wireless communication device, the survival time; and providing, to a physical layer of the first wireless communication device, the survival time.

Aspect 4 includes the method of any of aspects 1-3, wherein: the at least one parameter comprises a channel access priority class (CAPC) index value; and the second LBT procedure is based on the CAPC index value.

Aspect 5 includes the method of any of aspects 1-4, wherein the CAPC index value is based on a remaining time duration within the survival time satisfying a threshold.

Aspect 6 includes the method of any of aspects 1-5, wherein the CAPC index value is based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.

Aspect 7 includes the method of any of aspects 1-6, wherein the CAPC index value is based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.

Aspect 8 includes the method of any of aspects 1-7, wherein the at least one parameter comprises an energy detection threshold associated with the second LBT procedure.

Aspect 9 includes the method of any of aspects 1-8, wherein the energy detection threshold is based on a remaining time duration within the survival time satisfying a threshold.

Aspect 10 includes the method of any of aspects 1-9, wherein the energy detection threshold is based on a number of remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.

Aspect 11 includes the method of any of aspects 1-10, wherein the energy detection threshold is based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.

Aspect 12 includes the method of any of aspects 1-11, further comprising transmitting, to the second wireless communication device based on the second LBT procedure being successful during the survival time, one or more additional TB (s) of the plurality of TBs.

Aspect 13 includes the method of any of aspects 1-12, wherein a channel access priority class (CAPC) index value associated with the second LBT procedure is less than or equal to a CAPC index value associated with the first LBT procedure.

Aspect 14 includes the method of any of aspects 1-13, wherein an energy detection threshold associated with the second LBT procedure is less than or equal to an energy detection threshold associated with the first LBT procedure.

Aspect 15 includes the method of any of aspects 1-14, wherein the at least one parameter of the second LBT procedure is further based on a traffic priority associated with the one or more TBs.

Aspect 16 includes the method of any of aspects 1-15, wherein the first wireless communication device comprises a user equipment and the second wireless communication device comprises a network unit.

Aspect 17 includes the method of any of aspects 1-16, wherein the first wireless communication device comprises a network unit and the second wireless communication device comprises a user equipment.

Aspect 18 includes the method of any of aspects 1-17, wherein the first wireless communication device comprises a first user equipment and the second wireless communication device comprises a second user equipment.

Aspect 19 includes a method of wireless communication performed by a first wireless communication device, the method comprising transmitting, to a second wireless communication device, an indicator indicating a survival time associated with a plurality of TBs; performing a listen-before-talk (LBT) procedure in a shared frequency band; transmitting, to the second wireless communication device based on the LBT procedure being successful, a channel occupancy time (COT) sharing request; receiving, from the second wireless communication device, an indicator to share the COT; and transmitting, during the COT, one or more TBs of the plurality of TBs.

Aspect 20 includes the method of aspect 19, wherein the LBT procedure comprises a category 2 LBT procedure.

Aspect 21 includes the method of any of aspects 19-20, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining number of TB (s) of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.

Aspect 22 includes the method of any of aspects 19-21, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.

Aspect 23 includes the method of any of aspects 19-22, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining time duration within the survival time satisfying a threshold.

Aspect 24 includes the method of any of aspects 19-23, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request using a physical sidelink feedback channel (PSFCH) resource pool.

Aspect 25 includes the method of any of aspects 19-24, wherein the transmitting the COT sharing request comprises transmitting, using a COT sharing request resource pool, the COT sharing request.

Aspect 26 includes the method of any of aspects 19-25, wherein the transmitting the one or more TBs comprises transmitting the one or more TBs to the second wireless communication device.

Aspect 27 includes the method of any of aspects 19-26, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request to a plurality of wireless communication devices, wherein the plurality of wireless communication devices includes the second wireless communication device.

Aspect 28 includes the method of any of aspects 19-27, wherein the transmitting the indicator comprises transmitting the indicator via at least one of downlink control information (DCI) , sidelink control information (SCI) , a physical downlink control channel (PDCCH) communication, a physical uplink control channel (PUCCH) communication, a physical sidelink control channel (PSCCH) communication, a physical sidelink feedback channel (PSFCH) communication, or a radio resource control (RRC) message.

Aspect 29 includes the method of any of aspects 19-28, wherein the first wireless communication device comprises a user equipment and the second wireless communication device comprises a network unit.

Aspect 30 includes the method of any of aspects 19-29, wherein the first wireless communication device comprises a network unit and the second wireless communication device comprises a user equipment.

Aspect 31 includes the method of any of aspects 19-30, wherein the first wireless communication device comprises a first user equipment and the second wireless communication device comprises a second user equipment.

Aspect 32 includes a non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising one or more instructions that, when executed by one or more processors of a first wireless communication device perform any one of aspects 1-18.

Aspect 33 includes a non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising one or more instructions that, when executed by one or more processors of a first wireless communication device, cause the network unit to perform any one of aspects 19-31.

Aspect 34 includes a first wireless communication device comprising one or more means to perform any one or more of aspects 1-18.

Aspect 35 includes a first wireless communication device comprising one or more means to perform any one or more of aspects 19-31.

Aspect 36 includes a first wireless communication device comprising a memory; a transceiver; and at least one processor coupled to the memory and the transceiver, wherein the first wireless communication device is configured to perform any one or more of aspects 1-18.

Aspect 37 includes a first wireless communication device comprising a memory; a transceiver; and at least one processor coupled to the memory and the transceiver, wherein the first wireless communication device is configured to perform any one or more of aspects 19-31.

Information and signals 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 may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. 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) .

As those of some skill in this art will by now appreciate and depending on the particular application at hand, many modifications, substitutions and variations may be made in and to the materials, apparatus, configurations and methods of use of the devices of the present disclosure without departing from the spirit and scope thereof. In light of this, the scope of the present disclosure should not be limited to that of the particular instances illustrated and described herein, as they are merely by way of some examples thereof, but rather, should be fully commensurate with that of the claims appended hereafter and their functional equivalents.

Claims

A method of wireless communication performed by a first wireless communication device, the method comprising:

performing a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TB (s) ) ;

transmitting, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs; and

performing a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.
The method of claim 1, wherein:

the at least one parameter comprises a second channel access priority class (CAPC) index value; and

the second LBT procedure is based on the second CAPC index value.
The method of claim 2, wherein the second CAPC index value is based on a remaining time duration within the survival time satisfying a threshold.
The method of claim 2, wherein the second CAPC index value is based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.
The method of claim 2, wherein the second CAPC index value is based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.
The method of claim 1, wherein the at least one parameter comprises an energy detection threshold associated with the second LBT procedure.
The method of claim 6, wherein the energy detection threshold is based on a remaining time duration within the survival time satisfying a threshold.
The method of claim 6, wherein the energy detection threshold is based on a number of remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.
The method of claim 6, wherein the energy detection threshold is based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.
A method of wireless communication performed by a first wireless communication device, the method comprising:

transmitting, to a second wireless communication device, an indicator indicating a survival time associated with a plurality of TBs;

performing a listen-before-talk (LBT) procedure in a shared frequency band;

transmitting, to the second wireless communication device based on the LBT procedure being successful, a channel occupancy time (COT) sharing request;

receiving, from the second wireless communication device, an indicator to share the COT; and

transmitting, during the COT, one or more TBs of the plurality of TBs.
The method of claim 10, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.
The method of claim 10, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.
The method of claim 10, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining time duration within the survival time satisfying a threshold.
The method of claim 10, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request using a physical sidelink feedback channel (PSFCH) resource pool.
The method of claim 10, wherein the transmitting the COT sharing request comprises transmitting, using a COT sharing request resource pool, the COT sharing request.
A first wireless communication device comprising:

a memory;

a transceiver; and

at least one processor coupled to the memory and the transceiver, wherein the first wireless communication device is configured to:

perform a first listen-before-talk (LBT) procedure in a shared frequency band, wherein a category of the first LBT procedure is based on a first channel access priority class (CAPC) index value associated with a plurality of transport blocks (TBs) ;

transmit, to a second wireless communication device based on the first LBT procedure being successful, one or more TBs of the plurality of TBs; and

perform a second LBT procedure, wherein at least one parameter of the second LBT procedure is based on a survival time associated with the one or more TBs.
The first wireless communication device of claim 16, wherein:

the at least one parameter comprises a channel access priority class (CAPC) index value; and

the second LBT procedure is based on the CAPC index value.
The first wireless communication device of claim 17, wherein the CAPC index value is based on a remaining time duration within the survival time satisfying a threshold.
The first wireless communication device of claim 17, wherein the CAPC index value is based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.
The first wireless communication device of claim 17, wherein the CAPC index value is based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.
The first wireless communication device of claim 16, wherein the at least one parameter comprises an energy detection threshold associated with the second LBT procedure.
The first wireless communication device of claim 21, wherein the energy detection threshold is based on a remaining time duration within the survival time satisfying a threshold.
The first wireless communication device of claim 21, wherein the energy detection threshold is based on a number of remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.
The first wireless communication device of claim 21, wherein the energy detection threshold is based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.
A first wireless communication device comprising:

a memory;

a transceiver; and

at least one processor coupled to the memory and the transceiver, wherein the first wireless communication device is configured to:

transmit, to a second wireless communication device, an indicator indicating a survival time associated with a plurality of TBs;

perform a listen-before-talk (LBT) procedure in a shared frequency band;

transmit, to the second wireless communication device based on the LBT procedure being successful, a channel occupancy time (COT) sharing request;

receive from the second wireless communication device, an indicator to share the COT; and

transmit, during the COT, one or more TBs of the plurality of TBs.
The first wireless communication device of claim 25, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining number of TBs of the plurality of TBs scheduled to be transmitted within the survival time satisfying a threshold.
The first wireless communication device of claim 25, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining number of the one or more TBs of the plurality of TBs scheduled to be retransmitted within the survival time satisfying a threshold.
The first wireless communication device of claim 25, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request based on a remaining time duration within the survival time satisfying a threshold.
The first wireless communication device of claim 25, wherein the transmitting the COT sharing request comprises transmitting the COT sharing request using a physical sidelink feedback channel (PSFCH) resource pool.
The first wireless communication device of claim 25, wherein the transmitting the COT sharing request comprises transmitting, using a COT sharing request resource pool, the COT sharing request.