Techniques for enhancing time division multiplexing and frequency division multiplexing operations for sidelink unlicensed communications

Abstract

Aspects of the present disclosure relate to techniques for ensuring that for both out-of-COT and within-COT preemption window periods, other UEs that may have reserved resources within the same resource selection window are allowed (or at least not blocked) to gain access to a shared channel during their respective reserved resource periods.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Greek patent application serial number 20220100685, filed on August 12, 2022, entitled "TECHNIQUES FORENHANCING TIMEDIVISION MULTIPLEXING AND FREQUENCY DIVISION MULTIPLEXING OPERATION FORSIDELINK-UNLICENSED COMMUNICATIONS", which application has been assigned to the assignee of the present invention and is incorporated herein by reference in its entirety. Background Art Technical Field

[0003] The present disclosure relates generally to communication systems, and more particularly to techniques for enhancing time division multiplexing (TDM) and frequency division multiplexing (FDM) operations for sidelink unlicensed (SL-U) communications over a shared spectrum. Background Art

[0005] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0006] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continued mobile broadband evolution promulgated by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)) and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Certain aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard.

[0007] Therefore, further improvements to 5G NR technology are needed. In addition, these improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. For example, it is desirable to improve the efficiency and latency associated with the mobility of user equipment (UE) communicating with network entities. Summary of the invention

[0008] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of these aspects. This summary is not an extensive overview of all contemplated aspects, and is neither intended to identify key or important elements of all aspects, nor to describe the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description presented later.

[0009] Various aspects of the present disclosure relate to techniques for ensuring that, due to resource selection and transmission by a transmitter UE, other user equipments (UEs) that may have reserved resources and / or high priority services within the same resource selection window are allowed (or not blocked) to gain access to a shared channel during their respective reserved resource time periods, both outside of a channel occupancy time (COT) and within a preemption window time period within the COT.

[0010] In particular, in some cases, a transmitter UE (e.g., Tx UE) may select multiple resources within a resource selection window for sidelink communication with a receiver UE (e.g., Rx UE) such that access by any other UE (particularly a UE with a higher priority than the first UE) in a shared channel is not affected. Thus, in some cases, if a resource candidate selection would risk blocking a high priority transmission from another UE (within the preemption window T) that has made its resource reservation, the Tx UE may adjust the selection of multiple resources within the resource selection window to align with one of the other reserving UEs. Thus, the Tx UE listen-before-talk (LBT) procedure or transmission will not adversely affect the performance of other UEs on the shared network.

[0011] In addition, before initiating transmission within the resource selection window, the Tx UE may perform a last-minute evaluation as part of the LBT procedure, and if the Tx UE determines that another UE has made a reservation within the resource selection window (e.g., a new high priority reservation that was not previously detected during the selection process), and that reservation will be affected if the transmitter UE continues to transmit, the Tx UE may modify or adjust the starting point of its transmission to align with the new high priority reservation.

[0012] In other scenarios (e.g., when the Tx UE is within the reserved COT and performs a reassessment during the COT to detect a new high-priority reservation made by another UE), the Tx UE may modify its reservation by: (1) abandoning the COT T time slots (e.g., 2 time slots) before the high-priority reservation made by the other UE to allow the other UE to perform its LBT procedure and packet transmission during the preemption of resources; or (2) initiating COT sharing with the high-priority UE if both UEs support COT sharing. In the case of COT sharing, the Tx UE may generate a gap within the resource for the high-priority UE to perform Type 2 LBT without interference, but if the resources are non-overlapping, both UEs may continue to transmit (FDM).

[0013] In an example aspect, a method for wireless communication by a user equipment is included, which may include selecting multiple resources within a resource selection window for communication from a first user equipment (UE) to a second UE. Multiple resources may be selected within the resource selection window to allow one or more other UEs with higher priority transmission than the first UE to obtain access to a shared channel. And the multiple resources selected by the first UE may have at least partially overlapping frequency resources reserved by one or more other UEs. The method may also include performing a listen-before-talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE. The method may also include sending one or more packets from the first UE to the second UE via the multiple resources selected within the resource selection window based on successful completion of the LBT procedure.

[0014] Another example aspect includes a device for wireless communication by a user equipment, the device including a memory and a processor coupled to the memory. The method may include instructions executable by the processor to select multiple resources within a resource selection window for communication from a first user equipment (UE) to a second UE. Multiple resources may be selected within the resource selection window to allow one or more other UEs with a higher priority transmission than the first UE to obtain access to a shared channel. And the multiple resources selected by the first UE may have at least partially overlapping frequency resources reserved by one or more other UEs. The instructions executable by the processor may also be configured to perform an LBT procedure at the first UE before initiating transmission from the first UE to the second UE. Additionally, the instructions executable by the processor may also be configured to send one or more packets from the first UE to the second UE through multiple resources selected within the resource selection window based on the successful completion of the LBT procedure.

[0015] Another example includes an apparatus for wireless communication by a user equipment, the apparatus including a component for selecting multiple resources within a resource selection window for communication from a first user equipment (UE) to a second UE. Multiple resources may be selected within the resource selection window to allow one or more other UEs with higher priority transmission than the first UE to obtain access to a shared channel. And the multiple resources selected by the first UE may have at least partially overlapping frequency resources reserved by one or more other UEs. The apparatus may also include a component for performing a listen-before-talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE. The apparatus may also include a component for sending one or more packets from the first UE to the second UE via multiple resources selected within the resource selection window based on successful completion of the LBT procedure.

[0016] Another example includes a non-transitory computer-readable medium storing instructions executable by a processor for wireless communication. The instructions executable by the processor include instructions for selecting multiple resources within a resource selection window for communication from a first user equipment (UE) to a second UE. Multiple resources may be selected within the resource selection window to allow one or more other UEs with a higher priority transmission than the first UE to obtain access to a shared channel. And the multiple resources selected by the first UE may have at least partially overlapping frequency resources reserved by one or more other UEs. The instructions executable by the processor also include instructions for performing a listen-before-talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE. The instructions executable by the processor also include instructions for sending one or more packets from the first UE to the second UE through multiple resources selected within the resource selection window based on the successful completion of the LBT procedure.

[0017] To achieve the foregoing and related ends, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail some illustrative features of one or more aspects. However, these features are merely indicative of some of the various ways in which the principles of the various aspects may be employed, and this specification is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1A is a diagram illustrating an example of a wireless communication system and an access network.

[0019] Figure 1B is a diagram illustrating an example of a decomposed base station architecture according to various aspects of the present disclosure.

[0020] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0021] Figure 2B is a diagram illustrating an example of downlink (DL) channels within a subframe according to various aspects of the present disclosure.

[0022] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0023] Figure 2D is a diagram illustrating an example of uplink (UL) channels within a subframe according to various aspects of the present disclosure.

[0024] Figure 3A is an example timing diagram of resource selection according to various aspects of the present disclosure.

[0025] Figure 3B is an example resource selection window that allows a UE to select a number of resources exceeding the number of transport blocks (TBs) that the UE can deliver in accordance with various aspects of the present disclosure.

[0026] Figure 3C is an example timing diagram that allows a UE to initiate transmission before a slot boundary in accordance with various aspects of the present disclosure.

[0027] Figure 4A is an example of resource selection for preemption outside of a COT according to various aspects of the present disclosure.

[0028] Figure 4B is an example of adjusting transmission packets on a slot and subchannel basis based in part on the presence of other UE reservations within a resource selection window in accordance with various aspects of the present disclosure.

[0029] Figure 5A is an example of a Tx UE adapting to the transmissions of other UEs once the transmission within the COT has been initiated.

[0030] Figure 5B is another example of the Tx UE adapting to the transmissions of other UEs once the transmission within the COT has been initiated.

[0031] Figure 6 is a schematic diagram of an example implementation of various components of user equipment according to various aspects of the present disclosure.

[0032] Figure 7 is a flow chart of an example of a method of wireless communication implemented by a UE according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0033] Some wireless communication systems may support sidelink communications between user equipment (UE). Real-world applications of sidelink communications may include UE-to-network relay, vehicle-to-vehicle (V2V) communications, vehicle-to-everything (V2X) communications, Internet of Everything (IoE) communications, Internet of Things (IoT) communications, mission-critical mesh networks, and / or various other suitable applications.

[0034] Based on the resource allocation method, two different categories of sidelink communication are known: Mode 1 communication and Mode 2 communication. Mode 1 communication is a method in which a base station allocates available resources for direct communication between terminals and can be used when all terminals performing sidelink communication are within coverage.

[0035] Mode 2 communication is a method in which each terminal selects available resources for direct communication. Mode 2 communication can be used even when the terminal is out of coverage. However, because the base station may not intervene in resource allocation, the UE may need to identify the available resources by itself, and the base station may implement a sensing process to determine which resources each terminal can use. For example, the base station may allocate a resource pool to multiple UEs, and each UE may autonomously perform the steps of resource selection. In some examples, the UE may perform a listen-before-talk (LBT) procedure to obtain access to a sidelink bandwidth part (BWP) for sidelink transmission. Sensing can be used to identify resources available for the sidelink so as to decode the physical sidelink control channel (PSCCH) during a sensing window of a specific time period before performing sidelink transmission. Each UE may also perform resource reservation and signal via a sidelink control information (SCI) message to reserve up to two additional resources for retransmission. Various aspects of the present disclosure relate to mode 2 communication.

[0036] In particular, in some examples, licensed spectrum is used to convey sidelink communications (e.g., unlike wireless local area networks that typically use unlicensed spectrum). An example of sidelink communications is PC5, for example, as used in V2V, Long Term Evolution (LTE), and / or New Radio (NR). In some cases, a UE may communicate using one or more frequency bands associated with a shared radio frequency spectrum, which may be referred to as an unlicensed radio frequency spectrum band. The shared spectrum may include radio frequency bands that may not be reserved, allocated, or licensed for a particular use case or a particular radio access technology (RAT). In such a system, the UE may perform a listen-before-talk (LBT) procedure to obtain access to a sidelink bandwidth part (BWP) for sidelink transmissions.

[0037] Deploying a sidelink in an unlicensed spectrum is called Sidelink Unlicensed (SL-U). To avoid conflicts in SL-U operation where all UEs compete for resources, the UE may employ the LBT procedure to monitor transmission opportunities. LBT allows UEs to share the same channel. When LBT is enabled, the UE continuously monitors the channel so that it transmits only when the channel is not in use or in resources not reserved by other UEs. When LBT passes, the UE may continue to transmit. However, when LBT fails, the UE may refrain from transmitting in the channel.

[0038] Typically, SL-U operations after LBT failure may include resource reselection, where the UE may try again to select a limited number of resources for retransmission. In such cases, LBT failure may trigger medium access layer (MAC) layer-based resource reselection for additional resources. However, since MAC layer-based resource reselection has a long delay, the additional resources may not be available when needed. In such cases, if the transmitter UE determines to use a certain resource, these resources may not be available at the requested time. And even if a resource is selected, it is not certain whether the selected resource can be accessed in time, which may trigger another resource reselection and thus reduce throughput due to additional latency.

[0039] Additionally, in some cases, reserved resources may not be utilized. For example, if a first UE that initially selects and reserves certain resources on a shared channel may choose not to transmit over the reserved resources at a particular time. In such cases, other UEs (e.g., one or more second UEs) that monitor the reservation made by the first UE may unnecessarily exclude such resources during the resource selection procedure for the second UE, which reduces overall system capacity.

[0040] In practice, due to potential LBT uncertainty and resource scarcity, a UE operating in SL-U may select longer resource allocations to increase the probability of completing the LBT procedure. The UE may also over-book the number of resources used for transmission in order to prevent resources from being wasted by other UEs. In practice, such a solution may include configuring the UE to select more resources than the number of transport blocks (TBs) used for initial transmission. The reservation of multiple resources, in particular more than multiple TBs of resources, may allow the transmitter UE to have multiple LBT opportunities. The selected resources may be continuous in time and multiple TBs for initial transmission may be sent in one COT. Therefore, such a solution may result in lower latency for the transmitter UE because the improved resource selection for initial transmission in SL-U operation minimizes transmission delays due to LBT failures.

[0041] However, such solutions also bring many disadvantages, including inter-UE blocking. An "inter-UE blocking" scenario may occur when a first UE's transmission blocks the LBT of a second UE, even though the two transmissions would not conflict because the UEs would transmit during different time periods (TDM) or at different frequencies (FDM). Such a scenario may occur in two cases.

[0042] First, in frequency division multiplexing (FDM), multiple UEs (e.g., a first UE and a second UE) with non-overlapping frequency allocations in the same LBT bandwidth portion (e.g., the first UE reserves the first subband of the time slot, and the second UE reserves the second subband within the same time slot) may complete their respective LBTs at different times. For example, the first UE may complete the LBT first, and the second UE may complete the LBT second. However, in such cases, the UE that completes the LBT later (e.g., the second UE) may not be able to successfully access the channel because the LBT of the second UE will fail due to the earlier start of transmission of the first UE at the first subband of the time slot. Therefore, although the second UE can utilize the second subband (i.e., a non-overlapping frequency allocation compared to the first UE that reserved the first subband), the second UE will still be denied access to the channel due to the earlier start of transmission of the first UE on the channel.

[0043] Second, in time division multiplexing (TDM), if multiple UEs select non-overlapping time allocations (e.g., a first UE selects a first time slot, and a second UE selects a second time slot). In such cases, the LBT of the second UE for transmission in the second time slot will occur during the first time slot. However, given the fact that the first UE will transmit during the first time slot, the second UE may not be able to clear the LBT for the second time slot. Therefore, due to inter-UE blocking, the second UE may be deprived of the opportunity to transmit during the second time slot even though resources in the second time slot are still available.

[0044] Therefore, inter-UE blocking may adversely affect bandwidth utilization and prevent other UEs from accessing the channel. Such blocking may also adversely affect mission-critical services of high priority UEs that may otherwise be prevented from accessing the shared channel.

[0045] Various aspects of the present disclosure relate to techniques for ensuring that for both out-of-COT and in-COT preemption window time periods, other UEs that may have reserved resources within the same resource selection window are allowed (or at least not blocked) to gain access to a shared channel during their respective reserved resource time periods.

[0046] In particular, in some cases, a transmitter UE (e.g., Tx UE) may select multiple resources within a resource selection window for sidelink communication with a receiver UE (e.g., Rx UE) such that access by any other UE in the shared channel (particularly a UE with a higher priority than the first UE) is not affected. Thus, in some cases, if the resource candidate selection would risk blocking a high priority transmission from another UE (within the preemption window T) that has made its resource reservation, the Tx UE may adjust the selection of multiple resources within the resource selection window to align with one of the other reserving UEs. Thus, the Tx UEELBT procedure or transmission will not adversely affect the performance of other UEs on the shared network.

[0047] In addition, before initiating transmission within the resource selection window, the Tx UE may perform a last-minute evaluation as part of the LBT procedure, and if the Tx UE determines that another UE has made a reservation within the resource selection window (e.g., a new high priority reservation that was not previously detected during the selection process), and that reservation will be affected if the transmitter UE continues to transmit, the Tx UE may modify or adjust the starting point of its transmission to align with the new high priority reservation.

[0048] In other scenarios (e.g., when the Tx UE is within the reserved COT and performs a reassessment during the COT to detect a new high-priority reservation made by another UE), the Tx UE may modify the reservation by: (1) abandoning the COT T time slots (e.g., 2 time slots) before the high-priority reservation made by the other UE to allow the other UE to perform its LBT procedure and packet transmission during the preemption of resources; or (2) initiating COT sharing with the high-priority UE if both UEs support COT sharing. In the case of COT sharing, the Tx UE may generate a gap within the resource for the high-priority UE to perform Type 2 LBT without interference, but if the resources are non-overlapping, both UEs may continue to transmit (FDM).

[0049] The specific embodiments described below in conjunction with the accompanying drawings are intended as descriptions of various configurations and are not intended to represent the only configurations with which the concepts described herein can be practiced. In order to provide a thorough understanding of the various concepts, the specific embodiments include specific details. However, it is apparent to those skilled in the art that these concepts can be practiced without these specific details. In some cases, well-known structures and components are shown in block diagram form to avoid blurring such concepts.

[0050] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0051] As an example, an element, or any part of an element, or any combination of elements can be implemented as a "processing system", which includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware configured to perform various functionalities described throughout the present disclosure. One or more processors in a processing system can execute software. Whether it is referred to as software, firmware, middleware, microcode, hardware description language, or other names, software should be widely interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc.

[0052] Therefore, in one or more example embodiments, the described functions can be implemented with hardware, software or any combination thereof. If implemented in software, the function can be stored or encoded on a computer-readable medium as one or more instructions or codes. Computer-readable media include computer storage media. Storage media can be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media can include a random access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), an optical disk storage device, a magnetic disk storage device, other magnetic storage devices, a combination of computer-readable media of the above type, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

[0053] Figure 1A is a diagram illustrating an example of a wireless communication system 100 (also referred to as a wireless wide area network (WWAN)) that includes a base station 102 (also referred to herein as a network entity), a user equipment (UE) 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)).

[0054] One or more UEs in UE 104 may include a communication management component 198 that is operable to perform a technique for selecting a plurality of resources within a resource selection window for communication from a first UE to a second UE, wherein the plurality of resources may be selected within the resource selection window to allow one or more additional UEs having a higher priority transmission than the first UE and resources reserved by the one or more UEs within a preemption window of the plurality of resources to obtain access to a shared channel. The communication management component 198 may also perform an LBT procedure at the first UE before initiating transmission from the first UE to the second UE. The communication management component 198 may also, based on successful completion of the LBT procedure, send one or more packets from the first UE to the second UE using the plurality of resources selected within the resource selection window. In some examples, the communication management component 198 may perform one or more functions as disclosed herein for the UE.

[0055] Base station (or network entity) 102 may include macro cells (high-power cellular base stations) and / or small cells (low-power cellular base stations). Macro cells include base stations. Small cells include femto cells, pico cells, and micro cells. Base station 102 may be configured as a decomposed RAN (D-RAN) or open RAN (O-RAN) architecture, in which functionality is split between multiple units (such as a central unit (CU), one or more distributed units (DUs), or radio units (RUs)). Such an architecture may be configured to utilize a protocol stack that is logically split between one or more units (such as one or more CUs and one or more DUs). In some aspects, a CU may be implemented within an edge RAN node, and in some aspects, one or more DUs may be co-located with a CU, or may be geographically distributed in one or more RAN nodes. A DU may be implemented to communicate with one or more RUs. Any decomposed component in a D-RAN and / or O-RAN architecture may be referred to as a network entity herein.

[0056] The base station 102 configured for 4G Long Term Evolution (LTE) (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interface with the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). The base station 102 configured for 5G New Radio (NR) (collectively referred to as Next Generation RAN (NG-RAN)) can interface with the core network 190 via a second backhaul link 184. Among other functions, the base station 102 can also perform one or more of the following functions: delivery of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (eg, via the EPC 160 or the core network 190) via the third backhaul link 134 (eg, an X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 may be wired or wireless.

[0057] Base station 102 can communicate wirelessly with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). A communication link 120 between base station 102 and UE 104 can include an uplink (UL) (also called a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also called a forward link) transmission from base station 102 to UE 104. The communication link 120 can use multiple input multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmit diversity. The communication link can be through one or more carriers. For each carrier allocated in the carrier aggregation for up to a total of up to Yx MHz (x component carriers) for transmission in each direction, the base station 102 / UE 104 can use a spectrum with a bandwidth of up to Y megahertz (MHz) (e.g., 5 MHz, 10 MHz, 15 MHz, 20 MHz, 100 MHz, 400 MHz, etc.). These carriers may or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than for UL). The component carrier may include a primary component carrier and one or more secondary component carriers. The primary component carrier may be referred to as a primary cell (PCell) and the secondary component carrier may be referred to as a secondary cell (SCell).

[0058] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). D2D communication may be through a variety of wireless D2D communication systems, such as, for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0059] The wireless communication system may also include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154 in, for example, a 5 gigahertz (GHz) unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) to determine whether a channel is available prior to communication.

[0060] The small cell 102' may operate in licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell 102' may employ NR and use the same unlicensed spectrum (e.g., 5 GHz, etc.) as used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum may improve the coverage of the access network and / or increase the capacity of the access network.

[0061] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). Frequencies between FR1 and FR2 are typically referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as the “sub-6 GHz” band in various documents and articles. A similar naming issue sometimes occurs with respect to FR2, which is often (interchangeably) referred to as the “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz–300 GHz) identified as the “millimeter wave” band by the International Telecommunication Union (ITU).

[0062] In view of the above aspects, unless otherwise specifically stated, it should be understood that if the term "below 6 GHz" or the like is used in this document, it can broadly represent a frequency that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. In addition, unless otherwise specifically stated, it should be understood that if the term "millimeter wave" or the like is used in this document, it can broadly represent a frequency that can include mid-band frequencies, can be within FR2, or can be within the EHF band.

[0063] The base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), may include and / or be referred to as an eNB, a gNodeB (gNB), or another type of base station. Some base stations, such as gNB 180, may operate in the traditional sub-6 GHz spectrum, in millimeter wave frequencies, and / or near millimeter wave frequencies to communicate with the UE 104. When the gNB 180 operates in millimeter wave or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for path loss and short range. The base station 180 and the UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming.

[0064] Base station 180 may transmit beamformed signals in one or more transmit directions 182' to UE 104. UE 104 may receive beamformed signals from base station 180 in one or more receive directions 182". UE 104 may also transmit beamformed signals to base station 180 in one or more transmit directions. Base station 180 may receive beamformed signals from UE 104 in one or more receive directions. Base station 180 / UE 104 may perform beam training to determine the best receive direction and transmit direction for each of base station 180 / UE 104. The transmit direction and receive direction of base station 180 may be the same or may be different. The transmit direction and receive direction of UE 104 may be the same or may be different.

[0065] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, an MBMS gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Typically, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functions for MBMS user service configuration and delivery. BM-SC 170 may serve as an entry point for content provider MBMS delivery, may be used to authorize and initiate MBMS bearer services in a public land mobile network (PLMN), and may be used to schedule MBMS delivery. MBMS Gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area of ​​a broadcast specific service, and may be responsible for session management (start / stop) and for collecting eMBMS related billing information.

[0066] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides quality of service (QoS) flow and session management. All user IP packets are delivered through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IMS, a packet switching (PS) streaming service, and / or other IP services.

[0067] A base station may include and / or be referred to as a network entity, gNB, Node B, eNB, access point, base transceiver station, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), transmit receive point (TRP), or some other suitable term. Base station 102 provides an access point to EPC 160 or core network 190 for UE 104. Examples of UE 104 include cellular phones, smart phones, session initiation protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablets, smart devices, wearable devices, vehicles, electric meters, gas pumps, large or small kitchen appliances, healthcare equipment, implants, sensors / actuators, displays, or any other similarly functional device. Some of UE 104 may be referred to as IoT devices (e.g., parking meters, gas pumps, ovens, vehicles, monitors, cameras, industrial / manufacturing equipment, appliances, vehicles, robots, drones, etc.). IoT UEs may include machine type communication (MTC) / enhanced MTC (eMTC, also known as Category (CAT)-M, Cat M1) UEs, NB-IoT (also known as CATNB1) UEs, and other types of UEs. In the present disclosure, eMTC and NB-IoT may refer to future technologies that may evolve from or be based on these technologies. For example, eMTC may include FeMTC (further eMTC), eFeMTC (enhanced further eMTC), mMTC (massive MTC), etc., and NB-IoT may include eNB-IoT (enhanced NB-IoT), FeNB-IoT (further enhanced NB-IoT), etc. UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0068] Although the present disclosure may focus on 5G NR, the concepts and aspects described herein may be applicable to other similar areas such as LTE, Advanced LTE (LTE-A), Code Division Multiple Access (CDMA), Global System for Mobile Communications (GSM), and / or other wireless / radio access technologies.

[0069] Figure 1B1 is a diagram illustrating an example of a decomposed base station 101 architecture, any component or element of which may be referred to herein as a network entity. The decomposed base station 101 architecture may include one or more central units (CUs) 103, which may communicate directly with a core network 105 via a backhaul link, or indirectly with the core network 105 through one or more decomposed base station units (such as a near real-time (near RT) RAN intelligent controller (RIC) 107 via an E2 link, or a non-real-time (non-RT) RIC 109 associated with a service management and orchestration (SMO) framework 111, or both). The CU 103 may communicate with one or more distributed units (DUs) 113 via corresponding midhaul links (such as an F1 interface). The DU 113 may communicate with one or more radio units (RUs) 115 via corresponding fronthaul links. The RU 115 may communicate with corresponding UEs 104 via one or more radio frequency (RF) access links. In some implementations, a UE 104 may be served simultaneously by multiple RUs 115.

[0070] Each of the units (e.g., CU 103, DU 113, RU 115, and near-RT RIC 107, non-RT RIC 109, and SMO framework 111) may include or be coupled to one or more interfaces configured to receive or send signals, data, or information (collectively referred to as signals) via a wired or wireless transmission medium. Each of the units or an associated processor or controller that provides instructions to the communication interface of these units may be configured to communicate with one or more of the other units via a transmission medium. For example, these units may include a wired interface configured to receive or send signals to one or more of the other units via a wired transmission medium. Additionally, these units may include a wireless interface that may include a receiver, a transmitter, or a transceiver (such as a radio frequency (RF) transceiver) that is configured to receive or send signals, or both, to one or more of the other units on a wireless transmission medium.

[0071] In some aspects, CU 103 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), etc. Each control function may be implemented using an interface configured to communicate signals with other control functions hosted by CU 103. CU103 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 specific implementations, CU 103 may be logically split into one or more CU-UP units and one or more CU-CP units. When implemented in an O-RAN configuration, the CU-UP unit may communicate bidirectionally with the CU-CP unit via an interface (such as an E1 interface). As needed, CU 103 may be implemented to communicate with DU 113 for network control and signaling.

[0072] DU 113 may correspond to a logical unit that includes one or more base station functions for controlling the operation of one or more RUs 115. In some aspects, DU 113 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, etc.) at least in part according to a functional split such as those defined by the Third Generation Partnership Project (3GPP). In some aspects, DU 113 may also host one or more low PHY layers. Each layer (or module) may be implemented using an interface that is configured to communicate signals with other layers (and modules) hosted by DU 113 or with control functions hosted by CU 103.

[0073] The lower layer functionality may be implemented by one or more RUs 115. In some deployments, the RU 115 controlled by the DU 113 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, etc.), or both, based at least in part on functional splitting (such as lower layer functional splitting). In such an architecture, the RU 115 may be implemented to handle over-the-air (OTA) communications with one or more UEs 104. In some specific implementations, the real-time and non-real-time aspects of communicating with the control plane and user plane of the RU 115 may be controlled by the corresponding DU 113. In some scenarios, this configuration may enable the implementation of the DU 113 and the CU 103 in a cloud-based RAN architecture (such as a vRAN architecture).

[0074] The SMO framework 111 may be configured to support RAN deployment and configuration of non-virtualized network elements and virtualized network elements. For non-virtualized network elements, the SMO framework 111 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements, which may be managed via an operation and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO framework 111 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element lifecycle 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, but are not limited to, CU 103, DU 113, RU 115, and near-RT RIC 107. In some specific implementations, the SMO framework 111 may communicate with hardware aspects of the 4G RAN (such as an open eNB (O-eNB) 117) via the O1 interface. Additionally, in some specific implementations, the SMO framework 111 may communicate directly with one or more RUs 115 via the O1 interface. The SMO framework 111 may also include a non-RT RIC 109 configured to support the functionality of the SMO framework 111 .

[0075] The non-RT RIC 109 may be configured to include logic functions that implement non-real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and updating, or policy-based guidance of applications / features in the near-RT RIC 107. The non-RT RIC 109 may be coupled to or communicate with the near-RT RIC 107 (such as via an A1 interface). The near-RT RIC 107 may be configured to include logic functions that implement near-real-time control and optimization of RAN elements and resources via data collection and actions through an interface (such as via an E2 interface) that connects one or more CUs 103, one or more DUs 113, or both, and O-eNBs with the near-RT RIC 107.

[0076] In some implementations, in order to generate an AI / ML model to be deployed in the near-RT RIC 107, the non-RT RIC 109 may receive parameters or external enrichment information from an external server. Such information may be utilized by the near-RT RIC 107 and may be received from a non-network data source or from a network function at the SMO framework 111 or the non-RT RIC 109. In some examples, the non-RT RIC 109 or the near-RT RIC 107 may be configured to tune RAN behavior or performance. For example, the non-RT RIC 109 may monitor long-term trends and patterns of performance and employ AI / ML models to perform corrective actions through the SMO framework 111 (such as via reconfiguration of O1) or via the creation of RAN management policies (such as A1 policies).

[0077] FIG. 2A to FIG. 2D is a diagram of various frame structures, resources, and channels used by UE 104 and base station 102 / 180 for communications. Figure 2A FIG200 is a diagram illustrating an example of a first subframe within a 5G NR frame structure. Figure 2B FIG230 is a diagram illustrating an example of DL channels within a 5G NR subframe. Figure 2C FIG250 is a diagram illustrating an example of a second subframe within a 5G NR frame structure. Figure 2D FIG280 is a diagram illustrating an example of an UL channel within a 5G NR subframe. The 5G NR frame structure may be frequency division duplex (FDD) (wherein for a particular set of subcarriers (carrier system bandwidth), a subframe within the subcarrier set is dedicated to either DL or UL), or may be time division duplex (TDD) (wherein for a particular set of subcarriers (carrier system bandwidth), a subframe within the subcarrier set is dedicated to both DL and UL). Figure 2A , Figure 2C In the example provided, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible between DL / UL, and subframe 3 is configured with slot format 34 (most of which are UL). Although subframes 3 and 4 are shown as having slot formats 34 and 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and full UL, respectively. Other slot formats 2-61 include a mix of DL, UL and flexible symbols. The UE is configured with the slot format through the received slot format indicator (SFI) (dynamically configured through DL control information (DCI) or semi-statically / statically configured through radio resource control (RRC) signaling). Note that the following description also applies to the 5G NR frame structure as TDD.

[0078] Other wireless communication technologies may have different frame structures and / or different channels. For example, a 10 millisecond (ms) frame may be divided into 10 equally sized subframes (1 ms). Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4, or 2 symbols. Each time slot may include 7 or 14 symbols, depending on the time slot configuration. For time slot configuration 0, each time slot may include 14 symbols, and for time slot configuration 1, each time slot may include 7 symbols. The symbol on the DL may be a cyclic prefix (CP) orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbol (also known as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-constrained scenarios; limited to single-stream transmission). The number of time slots in a subframe is based on the time slot configuration and parameter set (numerology). For slot configuration 0, different parameter sets μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For slot configuration 1, different parameter sets 0 to 2 allow 2, 4, and 8 slots per subframe, respectively. Thus, for slot configuration 0 and parameter set μ, there are 14 symbols per slot and 2 per subframe. μ time slots. The subcarrier spacing and symbol length / duration are functions of the parameter set. The subcarrier spacing can be equal to 2 μ *15 kilohertz (kHz), where μ is parameter set 0 to 4. Therefore, the subcarrier spacing for parameter set μ=0 is 15 kHz, and the subcarrier spacing for parameter set μ=4 is 240 kHz. The symbol length / duration is inversely related to the subcarrier spacing. FIG. 2A to FIG. 2D An example is provided for slot configuration 0 with 14 symbols per slot and parameter set μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) that are frequency-division multiplexed (see Figure 2B ). Each BWP can have a specific set of parameters.

[0079] A resource grid may be used to represent the frame structure. Each slot includes a resource block (RB) (also referred to as a physical RB (PRB)) extending over 12 consecutive subcarriers. The resource grid is divided into a plurality of resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0080] like Figure 2AAs illustrated, some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) for channel estimation at the UE (indicated as R for a particular configuration). x , where 100x is the port number, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS). RS may also include beam measurement RS (BRS), beam refinement RS (BRRS) and phase tracking RS (PT-RS).

[0081] Figure 2B Examples of various DL channels within a subframe of a frame are illustrated. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), and each REG including four consecutive REs in an OFDM symbol. The PDCCH within a BWP may be referred to as a control resource set (CORESET). Additional BWPs may be located at higher and / or lower frequencies on the channel bandwidth. The primary synchronization signal (PSS) may be within symbol 2 of a specific subframe of a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. The secondary synchronization signal (SSS) may be within symbol 4 of a specific subframe of a frame. The SSS is used by the UE to determine the physical layer cell identification group number and radio frame timing. Based on the physical layer identification and the physical layer cell identification group number, the UE may determine the physical cell identifier (PCI). Based on the PCI, the UE may determine the position of the aforementioned DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also referred to as an SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not sent over the PBCH (such as the system information block (SIB)), and paging messages.

[0082] like Figure 2CAs illustrated in , some of the REs carry DM-RSs for channel estimation at the base station (indicated as R for one specific configuration, but other DM-RS configurations are possible). The UE may send a DM-RS for a physical uplink control channel (PUCCH) and a DM-RS for a physical uplink shared channel (PUSCH). The PUSCH DM-RS may be sent in the first or first two symbols of the PUSCH. Depending on whether a short PUCCH or a long PUCCH is sent and on the specific PUCCH format used, the PUCCH DM-RS may be sent in different configurations. The UE may send a sounding reference signal (SRS). The SRS may be sent in the last symbol of a subframe. The SRS may have a comb structure, and the UE may send the SRS on one of the teeth of the comb. The SRS may be used by the base station for channel quality estimation to achieve frequency-dependent scheduling of the UL.

[0083] Figure 2D Examples of various UL channels within a subframe of a frame are illustrated. The PUCCH may be located at a position as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) / negative acknowledgement (NACK) feedback. The PUSCH carries data and may be used to carry, among other things, a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0084] Figure 3A A timing diagram 300 for resource selection for SL-U communication is illustrated. As described above, in SL-U operation, the resource selection method allows the UE to select a limited number of resources 305 (e.g., for initial and subsequent transmissions). However, if the UE LBT operation 310 fails, the UE may seek additional resources (e.g., to clear the LBT procedure and retransmission again). In such cases, the LBT failure may trigger a medium access control (MAC) layer-based resource reselection for the additional resources. However, since the MAC layer-based resource reselection has a long delay, the additional resources may not be available when needed.

[0085] In some examples, to remedy the problem of LBT uncertainty, techniques may be implemented that allow the UE to reserve more resources than the number of TBs that the UE intends to deliver during the initial transmission. By reserving more resources than the number of TBs that the UE intends to deliver, the UE 104 may ensure multiple LBT opportunities. Figure 3AAs illustrated in FIG. , a first number of resources 305 may be selected in different time slots or resource blocks (RBs), and the transmitter UE 104 may perform an LBT procedure on one or more of the first number of resources as part of a last-minute evaluation 310 performed before initiating transmission.

[0086] Such techniques may result in lower latency because resource selection for initial transmissions in SL-U operations reduces and / or minimizes transmission delays due to a single LBT failure. And utilization of CPE may allow one or more UEs to initiate transmissions prior to a resource boundary in order to silence other UEs (since one or more second UEs may have their LBTs failed assuming the transmitter UE had already started transmitting prior to the boundary reservation).

[0087] Figure 3B 300 is an example resource selection window 330 that allows the UE to select a plurality of resources 305 that exceeds the number of TBs (e.g., first TB 315-a and second TB 315-b) that the UE can deliver to the second UE on the SL-U. In particular, in some examples, during the resource selection window 305, the MAC layer of the transmitter UE may overbook resources in time to provide more opportunities for the physical (PHY) layer of the transmitter UE to clear the LBT. In some cases, when interference in different time slots or different RB sets is uncorrelated, the PHY layer may have a higher probability of clearing the LBT in one of the other reserved opportunities. The selected resources (e.g., time slots) may be continuous or non-contiguous in time. The transmitter UE may also use the earliest opportunity based on time sorting to clear the LBT.

[0088] In certain aspects, the transmitter UE 104 performs LBT procedures across multiple LBT subbands. For example, when multiple frequency domain opportunities are available in the same time slot associated with the first number of resources, the transmitter UE may perform LBT across multiple LBT subbands that may be selected based on the preferred order indicated by the MAC.

[0089] Thus, in some cases, when the transmitter UE 104 has two TBs (e.g., TB0 315-a and TB1 315-b) to transmit, the UE may still select four consecutive resources 305 in time. In such cases, the transmitter UE 104 may use the first set of resources (e.g., resources "0" and "1") for the LBT procedure 320 that may end before the third resource 305 (resource "2"). Thus, the UE may transmit TB0 315-a and TB1 315-b within one COT in the selected resources "2" and "3".

[0090] Additionally, in Figure 3CIn some cases illustrated in , the selected resources may be contiguous in time, and multiple TBs for initial transmission may be sent in one COT. The UE may also indicate a cyclic prefix extension (CPE) duration for the selected resources during the initial transmission. This technique may allow the UE to modify the CPE so that the UE may start transmitting on the SL-U channel before the reserved block, rather than performing an entire resource reselection. In particular, in some cases of SL-U operation, multiple UEs 104 may compete for channel access at the same time. In such cases, there may be a traffic conflict when the expected transmissions of multiple UEs start at the same time. For example, multiple UEs may identify an empty channel before a timeslot boundary, and then start their respective transmissions at the timeslot boundary at the same time. As a result, multiple UEs may interfere with each other.

[0091] Thus, multiple contention time slots (e.g., 9 μs per time slot) may be provided before the time slot boundary with the CPE. Each UE may be hashed to one of the multiple starting points. In such cases, a UE that hashes to an earlier starting point may be allowed to start transmitting earlier so as to stop another UE that hashes to a later starting point. Therefore, it may be advantageous for the UE to select an earlier starting point from a set of starting points to transmit. However, in order to prevent all UEs from competing for an earlier starting point, the UE may select a starting point based on one or more rules that ensure fair access to all UEs. For example, the selection of a starting point may be based on a priority of transmission. Multiple rules may also include randomizing a starting point from a set of starting points (e.g., the starting point may not need to be fixed, and some randomness in the UE's selection of a starting point may improve fairness for multiple UEs). In other examples, different sets of starting points may be associated with different channel access priority category (CAPC) values. In yet another example, the UE may be configured to access an earlier starting point after the UE has failed the LBT procedure multiple times. For example, if the UE has been unable to perform the LBT procedure, the UE may be allowed to access an earlier starting point more actively.

[0092] However, "over-booking" of resources and utilizing CPE to gain early access to the SL-U channel provides a number of disadvantages, including inter-UE blocking. Specifically, in an "inter-UE blocking" scenario, resource selection and transmission by a first UE may block the LBT of a second UE, even though the two transmissions would not otherwise conflict. Over-booking resources or using CPE also does not prevent inter-UE blocking of higher priority UEs, as each UE aggressively over-books multiple resources and prevents other UEs from accessing the channel due to its self-interest in ensuring that its own packets are delivered over the channel. Such operations and techniques may have negative overall impacts, including impacts on services associated with eMBB or mission-critical services.

[0093] Various aspects of the present disclosure relate to techniques for ensuring that for both out-of-COT and in-COT preemption window time periods, other UEs that may have reserved resources within the same resource selection window are allowed (or at least not blocked) to gain access to a shared channel during their respective reserved resource time periods.

[0094] In particular, in some cases, a transmitter UE (e.g., Tx UE) may select multiple resources within a resource selection window for sidelink communication with a receiver UE (e.g., Rx UE) such that access by any other UE in the shared channel (particularly a UE with a higher priority than the first UE) is not affected. Thus, in some cases, if the resource candidate selection would risk blocking a high priority transmission from another UE (within the preemption window T) that has made its resource reservation, the Tx UE may adjust the selection of multiple resources within the resource selection window to align with one of the other reserving UEs. Thus, the Tx UEELBT procedure or transmission will not adversely affect the performance of other UEs on the shared network.

[0095] In addition, before initiating transmission within the resource selection window, the Tx UE may perform a last-minute evaluation as part of the LBT procedure, and if the Tx UE determines that another UE has made a reservation within the resource selection window (e.g., a new high priority reservation that was not previously detected during the selection process), and that reservation will be affected if the transmitter UE continues to transmit, the Tx UE may modify or adjust the starting point of its transmission to align with the new high priority reservation.

[0096] In other scenarios (e.g., when the Tx UE is within the reserved COT and performs a reassessment during the COT to detect a new high-priority reservation made by another UE), the Tx UE may modify its reservation by: (1) abandoning the COT T time slots (e.g., 2 time slots) before the high-priority reservation made by the other UE to allow the other UE to perform its LBT procedure and packet transmission during the preemption of resources; or (2) initiating COT sharing with the high-priority UE if both UEs support COT sharing. In the case of COT sharing, the Tx UE may generate a gap within the resource for the high-priority UE to perform Type 2 LBT without interference, but if the resources are non-overlapping, both UEs may continue to transmit (FDM).

[0097] Figure 4AIt is a resource selection diagram 400 for the out-of-COT preemption window. In some examples, the PHY layer of the Tx UE 104 can check the sensing window to identify candidate resources in the resource selection window (e.g., 405, 425). After identifying the set of candidate resources, the PHY layer can report the set of candidate resources to the MAC layer of the UE 104. Then, during a first time period (e.g., during the selection time period), the MAC layer can select one or more resources from the set of candidate resources within the resource selection window reported by the PHY layer for transmission during a second time period.

[0098] In some examples, the Tx UE MAC (e.g., for UE 1) can select resource 415-a within the selection window according to the parameter T (preemption window). However, if the candidate selection of resource 415-a will block the transmission of another UE (e.g., UE 2) (this other UE can be a high-priority UE or include high-priority traffic that has reserved resource 410-a within the preemption window (T), as shown in resource selection window 405), then the Tx UE 104 (UE 1) can modify its resource selection such that the reserved resource 415-b is aligned with the reserved resource 410-b of the high-priority UE (e.g., UE 1) (as shown in resource selection window 410).

[0099] For example, UE 1 can perform a long resource selection at t1 (the first time period) to start transmission at t2 (the second time period). Another UE (e.g., UE 2) can also perform resource reservation at t2 to start its transmission at t2'. In such cases, the Tx UE (UE 1) can perform a last-minute evaluation at a certain time period (e.g., t3) before the start of the transmission corresponding to UE 1 (e.g., t1'). In such scenarios, the selection of resource reservation from UE 2 can occur at the following times: (1) before UE1 makes its resource selection (e.g., t2 < t1), or (2) after UE1 has made its resource selection, but before UE1 starts transmitting on the reserved resources (e.g., t1 < t2 < t3).

[0100] Thus, in a first scenario (e.g., where the selection of resource reservation 410-a from UE 2 occurs before UE 1 makes its own resource selection 415-a (e.g., t2 < t1)), the Tx UE 104 (e.g., UE 1) may determine that the planned resource reservation 415-a for UE 1 may affect or be close to the LBT end time period for UE 2. In other words, the Tx UE 104 (e.g., UE 1) may determine that the planned transmission in resource 415-a may prevent one or more second UEs (e.g., UE 2) from initiating a transmission in the reserved resource 410-a. Thus, in order not to prevent or block other UEs from accessing the shared channel at their reserved resources, the Tx UE 104 (e.g., UE 1) may modify the starting resource to align with UE 2, as shown in resource selection window 425. This alignment may include selecting the starting point for the communication transmission for the Tx UE 104 (e.g., UE 1) from the originally scheduled t1' to t2', where the two UEs select different frequency resources (e.g., FDM) within the same time period. In other words, the starting points for the transmissions for both UE 1 and UE 2 will be aligned, and the frequency resources will be diverse, such that the two UEs 104 can independently initiate transmissions over the shared channel without affecting the ability of the other UE 104 to access the shared channel.

[0101] In a second scenario (e.g., the selection of the resource reservation from UE 2 may occur after UE1 has made its resource selection, but before UE1 starts transmitting on the reserved resources (e.g., t1 < t2 < t3)), UE 1 may perform a last moment assessment at t3 and determine the existence of the resource reservation 410-a from UE 2. In such cases, the Tx UE 104 (UE1) may defer the starting time of the transmission of UE 1 from t1' to t2', partially based on the priority of the UE. Thus, even if the Tx UE104 (e.g., UE 1) fails to identify any other UE that has made a resource reservation within the resource selection window at the time of the Tx UE 104 resource selection when initially selecting multiple resources 415-a, the techniques provided herein account for any subsequent resource reservation that may be made by another UE. For example, before initiating any transmission over the shared channel, the Tx UE 104 may perform a last moment assessment (e.g., LBT 420). In such cases, if a new high-priority reservation 410-a (e.g., which was not previously detected or reserved) is detected during the LBT 420, the Tx UE 104 may also modify the starting point of the Tx UE 104 transmission aligned with the reservation, as shown in the resource selection window 425. Such procedures may be handled as in Class 1 LBT when the device is not ready to transmit and will perform an additional LBT for up to 25 us before the start of the transmission.

[0102] Thus, features of the present disclosure address scenarios in which, for example, other UEs (e.g., one or more UEs 2) reserve resources 410-a when Tx UE 104 (e.g., UE 1) selects resources for its own transmission, or where the other UE's reservation arrives after Tx UE 104 has completed the reservation but before initiating a transmission.

[0103] Figure 4B 4 is an example of a resource selection window 450, which illustrates that the Tx UE 104 adjusts the transmission packet on a slot and subchannel basis based in part on the presence of other UE reservations within the resource selection window. As described above, in some examples, the Tx UE 104 may seek to send multiple TBs to the Rx UE 104. Therefore, the Tx UE 104 may select multiple resources within the resource selection window before starting the LBT. The Tx UE 104 that makes a "long" resource selection may be ready to start transmitting on the reserved resources once the Tx UE 104 clears the LBT. After clearing the LBT, the Tx UE 104 may send multiple TBs through the reserved resources.

[0104] Thus, as discussed above, the Tx UE 104 may select a different set of resources for each time slot based on any existing reservations by one or more other UEs (e.g., UE 2). The Tx UE 104 may also generate multiple versions of the packet (or packets) to be transmitted so that the Tx UE 104 may adjust the packets to be transmitted after LBT to align with the available resources.

[0105] In particular, the MAC layer of the Tx UE 104 may request a set of available resources from the PHY and determine which resources within the resource selection window are blocked by other UEs. The report from the PHY to the MAC may provide results for each time slot and subchannel, the results of the reference signal received power (RSRP) threshold processing, and the priority of other UEs that have reserved resources within the resource selection window. And based on the priority level of other UEs (e.g., UE 2) that have reserved resources, the Tx UE (e.g., UE 1) may adjust a specific time slot, subchannel, or CPE to send its own traffic.

[0106] For example, in time slot 0, the Tx UE 104 (e.g., UE 1) may reserve the first subchannel 455, the second subchannel 460, and the fourth subchannel 470. In the same time slot 0, another UE (e.g., UE 2) may reserve the third subchannel 465. The high-performance Tx UE 104 may prepare multiple versions of the first packet (e.g., the same TB) to avoid existing reservations, and select a version of the packet to be sent after the LBT is completed based on the priority of the Tx UE (e.g., UE 1) compared to another UE (e.g., UE 2) that has also reserved in the same time slot.

[0107] Therefore, in the illustrated example, if the priority of any UE is uncertain or unreasonable (case 1), both UE 1 and UE 2 may transmit in their respective reserved subchannels at a predetermined CPE (e.g., a transmission start time). However, if UE 1 has a higher priority than UE 2, UE 1 may not only transmit in its previously reserved first subchannel 455, second subchannel 460, and fourth subchannel 470, but may also initiate a longer CPE through each of the first subchannel 455, second subchannel 460, third subchannel 465, and fourth subchannel 470 so as to start transmitting on all subchannels in time slot 0 before UE 2. By starting to transmit earlier than the time slot 0 boundary, UE 1 is able to silence UE 2 without transmitting through the third subchannel 465. On the contrary, if UE 2 has a higher priority than UE 1, UE 1 may wait to start transmitting on the reserved first subchannel 455, second subchannel 460, and fourth subchannel 470 until the time slot 0 boundary. Therefore, UE 2, which has a higher priority than UE 1, will not be blocked from transmitting through its reserved third subchannel 465. In fact, by adjusting the CPE, UE 2 may also initiate its transmission on the third subchannel 465 earlier than UE 1 for time slot 0. Therefore, the Tx UE 104 (e.g., UE 1) can ensure that over-booked resources within the resource selection window will not adversely affect other UEs (especially those UEs with higher priority services).

[0108] Additionally or alternatively, once Tx UE 104 has initiated transmission within the COT, the UE may also respect the preemption of other UEs (e.g., UE 2) and either abandon the COT corresponding to Tx UE 104 or initiate COT sharing with other UEs to promote fair sharing of resources on the shared channel.

[0109] Figure 5Ais an example of a Tx UE 104 adapting to transmissions of other UEs once transmissions within the COT have been initiated. In some aspects, once the Tx UE 104 detects (possibly before the start of the COT) some reservations within the COT resources, one or more resource reservations of other UEs, the Tx UE 104 may adapt to resource preemption of other UEs based in part on the priority of the reservations. Thus, in one example, as Figure 5A As illustrated in , the Tx UE 104 may relinquish the COT at least T time slots (eg, two time slots, where T is the preemption window) before starting reservation for other UEs (eg, UE 2).

[0110] In other examples, such as Figure 5B As illustrated in , if other UEs support COT sharing, the Tx UE 104 may also share the COT with these UEs. In such cases, the Tx UE 104 may signal UE 2 to share COT so that the reserved UE (e.g., UE 2) can access the resources via Class 2 LBT. The Tx UE 104 may create a gap for the Class 2 LBT of UE 2, but if the resources are non-overlapping (e.g., FDM), it continues to transmit, which may require a short LBT to resume transmission. Additionally or alternatively, if the Tx UE 104 has data for the initiator, COT sharing may be allowed. In one case, a field may be added to the reserved SCI-1 to pre-declare the receiving UE to which the data is designated. In other examples, the COT initiator may invite another UE to share COT, and if the initiator is the destination ID of the TB, the responder may share.

[0111] In some examples, the preemption window value (T) may be determined individually for each UE, may be based on a function of the priority value in the UE SCI (e.g., the UE may utilize statistics of priority over time to maintain a list of neighbor UEs), a time window over which the function is calculated, or the preemption window value may be determined on a per reservation basis (e.g., based on the priority of the particular reservation).

[0112] Figure 6 The hardware components and subcomponents of a device (which may be a UE 104) for implementing one or more methods (eg, method 700) described herein according to various aspects of the present disclosure are illustrated. The UE 104 may be a reference Figure 1AExample of the disclosed UE 104. For example, one example of a specific implementation of the UE 104 may include various components, some of which have been described above, in addition to including components such as: one or more processors 612, memory 616, and transceiver 602 communicating via one or more buses 644, which can operate in conjunction with the communication management component 198 to perform the functions described herein in connection with one or more methods (e.g., 700) including the present disclosure.

[0113] In particular, the communication management component 198 may include a resource configuration component 620 for selecting a plurality of resources within a resource selection window for communication from a first UE to a second UE. The plurality of resources may be selected within the resource selection window to allow one or more additional UEs having a higher priority transmission than the first UE and resources reserved by one or more UEs within a preemption window of the plurality of resources to obtain access to the shared channel. The communication management component 198 may also include an LBT component 625 to perform an LBT procedure at the first UE before initiating transmission from the first UE to the second UE. The communication management component 198 may also include a sidelink communication component 630 to transmit one or more packets from the first UE to the second UE via the plurality of resources selected within the resource selection window based on successful completion of the LBT procedure.

[0114] The one or more processors 612, modem 614, memory 616, transceiver 602, RF front end 688 and one or more antennas 665 may be configured to support voice and / or data calls (simultaneously or non-simultaneously) in one or more wireless access technologies. In one aspect, the one or more processors 612 may include a modem 514 using one or more modem processors. Various functions associated with the communication management component 198 may be included in the modem 614 and / or processor 612, and in one aspect, may be performed by a single processor, while in other aspects, different functions of these functions may be performed by a combination of two or more different processors. For example, in one aspect, the one or more processors 612 may include a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or any one or any combination of transceiver processors associated with the transceiver 602. In other aspects, some of the features of the one or more processors 612 and / or modem 614 associated with the communication management component 198 may be performed by the transceiver 602.

[0115] The memory 616 may be configured to store data used herein and / or a local version of the application 675 executed by the at least one processor 612 or one or more of the communication management component 198 and / or its subcomponents. The memory 616 may include any type of computer-readable medium usable by a computer or the at least one processor 612, such as a random access memory (RAM), a read-only memory (ROM), a tape, a disk, an optical disk, a volatile memory, a non-volatile memory, and any combination thereof. In one aspect, for example, when the UE 104 is operating the at least one processor 612 to execute the communication management component 198 and / or one or more of its subcomponents, the memory 616 may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining the communication management component 198 and / or one or more of its subcomponents and / or data associated therewith.

[0116] The transceiver 602 may include at least one receiver 606 and at least one transmitter 608. The receiver 606 may include hardware, firmware, and / or software code executable by a processor for receiving data, the code including instructions and stored in a memory (e.g., a computer-readable medium). The receiver 606 may be, for example, a radio frequency (RF) receiver. In one aspect, the receiver 606 may receive a signal transmitted by at least one UE 104. Additionally, the receiver 606 may process such received signals and may also obtain measurements of the signals, such as, but not limited to, Ec / Io, SNR, RSRP, RSSI, etc. The transmitter 608 may include hardware, firmware, and / or software code executable by a processor for transmitting data, the code including instructions and stored in a memory (e.g., a computer-readable medium). Suitable examples of the transmitter 608 may include, but are not limited to, an RF transmitter.

[0117] Moreover, in an aspect, the transmitting device may include an RF front end 688 that may operate in communication with one or more antennas 665 and the transceiver 602 to receive and transmit radio transmissions, such as wireless communications transmitted by at least one base station 102 or wireless transmissions transmitted by a UE 104. The RF front end 688 may be connected to the one or more antennas 665 and may include one or more low noise amplifiers (LNAs) 690, one or more switches 692, one or more power amplifiers (PAs) 698, and one or more filters 696 for transmitting and receiving RF signals.

[0118] In one aspect, the LNA 690 may amplify the received signal at a desired output level. In one aspect, each LNA 690 may have a specified minimum gain value and a maximum gain value. In one aspect, the RF front end 688 may use one or more switches 692 to select a particular LNA 690 and its specified gain value based on the desired gain value for a particular application.

[0119] In addition, for example, the RF front end 688 can use one or more PAs 698 to amplify the signal for RF output at a desired output power level. In one aspect, each PA 698 can have a specified minimum gain value and a maximum gain value. In one aspect, the RF front end 688 can use one or more switches 692 to select a particular PA 698 and its specified gain value based on the desired gain value for a particular application.

[0120] Also, for example, the RF front end 658 can use one or more filters 696 to filter a received signal to obtain an input RF signal. Similarly, in one aspect, for example, the output from a corresponding PA 698 can be filtered using a corresponding filter 696 to produce an output signal for transmission. In one aspect, each filter 696 can be connected to a specific LNA 690 and / or PA 698. In one aspect, the RF front end 688 can use one or more switches 592 to select a transmit path or a receive path using a specified filter 696, LNA 690, and / or PA 698 based on a configuration as specified by the transceiver 602 and / or the processor 612.

[0121] Thus, the transceiver 602 can be configured to transmit and receive wireless signals through one or more antennas 665 via the RF front end 688. In one aspect, the transceiver 602 can be tuned to operate at a specified frequency so that the transmitting device can communicate, for example, with one or more base stations 102 or one or more cells associated with one or more base stations 102 or other UEs 104. In one aspect, the modem 614 can configure the transceiver 602 to operate at a specified frequency and power level based on the configuration of the transmitting device and the communication protocol used by the modem 614, for example.

[0122] In one aspect, the modem 614 can be a multi-band multi-mode modem that can process digital signals and communicate with the transceiver 602 so that the transceiver 602 is used to transmit and receive digital data. In one aspect, the modem 614 can be multi-band and can be configured to support multiple frequency bands for a specific communication protocol. In one aspect, the modem 614 can be multi-mode and configured to support multiple operating networks and communication protocols. In one aspect, the modem 614 can control one or more components of the transmitting device (e.g., RF front end 688, transceiver 602) to achieve signal transmission and / or reception with the network based on the specified modem configuration. In one aspect, the modem configuration can be based on the mode of the modem 614 and the frequency band in use. In another aspect, the modem configuration can be based on UE configuration information associated with the transmitting device, such as provided by the network during cell selection and / or cell reselection.

[0123] refer to Figure 7 , an example method 700 for wireless communication according to aspects of the present disclosure may be referred to as Figure 1A The discussed one or more UEs 104 are performed. Although the method 700 is described below with respect to elements of a UE 104, other components may be used to implement one or more of the steps described herein.

[0124] At block 705, method 700 may include selecting a plurality of resources within a resource selection window for communication from a first user equipment (UE) to a second UE. The plurality of resources may be selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to obtain access to a shared channel. And the plurality of resources selected by the first UE may have at least partially overlapping frequency resources reserved by one or more other UEs. In some examples, the method of block 705 may be performed by the processor 612, the modem 644, the communication management component 198, the resource configuration component 620, and / or one or more other components or subcomponents of the UE 104.

[0125] In some examples, multiple resources within the resource selection window may be selected such that a first start time for a transmission from a first UE to a second UE in a shared channel and a second start time for a higher priority transmission from one or more additional UEs may be no earlier than one time slot. In other examples, multiple resources within the resource selection window may be selected such that a first start time for a transmission from a first UE to a second UE in a shared channel and a second start time for a higher priority transmission from one or more additional UEs are aligned within a time slot. In other words, for UEs initiating transmissions within each time slot, the start times based on the CPE may be aligned.

[0126] In some examples, selecting multiple resources within a resource selection window for communication from a first UE to a second UE includes: receiving a first set of available resources of one or more time slots and subchannels within the resource selection window at the first UE. The method may also include selecting multiple resources within the resource selection window from the first set of available resources based on an identification of resources blocked by one or more other UEs having a higher priority transmission.

[0127] In some examples, selecting multiple resources within the resource selection window for communication from the first UE to the second UE includes selecting a sub-slot transmission start point for the multiple resources selected by the first UE. In some examples, the sub-slot transmission start point may indicate the CPE duration. In some aspects, at least partially overlapping frequency resources reserved by one or more other UEs may also indicate their respective sub-slot transmission start points.

[0128] In some examples, the partially overlapping frequency resources include overlapping LBT bandwidth required by one or more other UEs to complete the LBT procedure. Additionally or alternatively, the partially overlapping frequency resources may include overlapping subchannels of multiple resources selected as the first UE.

[0129] In some implementations, the processor 612, the modem 644, the communication management component 198, the resource configuration component 620, and / or one or more other components or subcomponents of the UE 104 may be configured and / or may define means for selecting a plurality of resources within a resource selection window for communication from a first user equipment (UE) to a second UE. The plurality of resources may be selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to obtain access to the shared channel. And the plurality of resources selected by the first UE may have at least partially overlapping frequency resources reserved by one or more other UEs.

[0130] At block 710, method 700 may include performing a listen-before-talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE. In some examples, the method of block 710 may be performed by the processor 612, the modem 644, the communication management component 198, the LBT component 625, and / or one or more other components or subcomponents of the UE 104.

[0131] In some examples, the processor 612, modem 644, communication management component 198, LBT component 625, and / or one or more other components or subcomponents of UE 104 may be configured as and / or may be defined as components for performing a listen-before-talk (LBT) procedure at the first UE prior to initiating a transmission from the first UE to a second UE.

[0132] At block 715, method 700 may include sending one or more packets from the first UE to the second UE via a plurality of resources selected within the resource selection window based on successful completion of the LBT procedure. In some aspects, the method of block 715 may be performed by the processor 612, modem 644, communication management component 198, sidelink communication component 630 of UE 104 in conjunction with transceiver 602 and / or one or more other components or subcomponents.

[0133] In some examples, sending one or more packets from a first UE to a second UE via multiple resources may include sending one or more packets with a modification to the selection of multiple resources within the resource selection window based on an LBT procedure identifying a resource conflict within the preemption window due to a reservation within the resource selection window by another UE, the other UE having a higher priority service than one or more packets scheduled for transmission by the first UE to the second UE. In some examples, the modification to the selection of multiple resources includes modifying one or more packets to accommodate the resource conflict within the preemption window. In some aspects, modifying the one or more packets may include generating multiple different versions of the one or more packets to be sent at the first UE before the first UE performs the LBT procedure, so that the first UE can select one of the different versions of the one or more packets to be sent that accommodates the resource conflict.

[0134] In some examples, sending one or more packets via multiple resources selected within a resource selection window includes detecting resource conflicts within the COT for one or more other UEs that have reserved resources and have a higher priority to send than the first UE. In some examples, the method may also include abandoning transmission from the first UE to the second UE at least T time slots (e.g., two or more time slots) before starting the higher priority transmission. In some aspects, the method may also signal COT sharing of resources from the first UE to one or more other UEs with higher priority to send that have resources reserved within the COT, and sending one or more packets from the first UE to the second UE via frequency resources that do not overlap with the one or more other UEs. In some aspects, signaling COT sharing includes identifying a destination identifier of the first UE within a sidelink control information (SCI) message.

[0135] In some examples, the preemption window may be determined on a per-UE or per-reservation basis.

[0136] In certain embodiments, the processor 612, modem 644, communication management component 198, sidelink communication component 630 of UE 104, together with the transceiver 602 and / or one or more other components or subcomponents may be configured as and / or may be defined as a means for sending one or more packets from a first UE to a second UE via a plurality of resources selected within a resource selection window based on successful completion of an LBT procedure.

[0137] Some further example clauses

[0138] Specific implementation examples are described in the following numbered clauses:

[0139] 1. A method for wireless communication, the method comprising:

[0140] selecting a plurality of resources within a resource selection window for communication from a first user equipment (UE) to a second UE, the plurality of resources being selectable within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and the plurality of resources selected by the first UE being able to have at least partially overlapping frequency resources reserved by the one or more other UEs;

[0141] performing a listen before talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE; and

[0142] Based on the successful completion of the LBT procedure, one or more packets are sent from the first UE to the second UE via the multiple resources selected within the resource selection window.

[0143] 2. A method according to clause 1, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE in the shared channel and a second start time for the one or more additional UEs to transmit the higher priority transmission are no earlier than one time slot.

[0144] 3. A method according to any of the preceding clauses, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE in the shared channel and a second start time for the one or more additional UEs to perform the higher priority transmission are aligned within a time slot.

[0145] 4. The method of any of the preceding clauses, wherein based on successful completion of the LBT procedure, sending the one or more packets through the plurality of resources selected within the resource selection window comprises:

[0146] The one or more packets having a modification to the selection of the multiple resources within the resource selection window are sent based on the LBT procedure identifying an overlapping frequency resource conflict due to a reservation by another UE, wherein the other UE has a higher priority service than the one or more packets scheduled for transmission by the first UE to the second UE.

[0147] 5. The method of any of the preceding clauses, wherein the modification of the selection of the plurality of resources comprises modifying the one or more packets to accommodate the resource conflict within a preemption window.

[0148] 6. A method according to any of the preceding clauses, wherein modifying the one or more packages comprises:

[0149] Before the first UE executes the LBT procedure, multiple different versions of the one or more packets to be sent are generated at the first UE, so that the first UE can select one of the different versions of the one or more packets to be sent that adapts to the resource conflict.

[0150] 7. A method according to any of the preceding clauses, wherein the partially overlapping frequency resources include overlapping LBT bandwidth required for the one or more other UEs to complete the LBT procedure or one or both of overlapping sub-channels of the multiple resources selected as the first UE.

[0151] 8. A method according to any of the preceding clauses, wherein selecting the plurality of resources within the resource selection window for communication from the first UE to the second UE comprises selecting a sub-slot transmission starting point for the plurality of resources selected for the first UE.

[0152] 9. A method according to any of the preceding clauses, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs indicate a sub-slot transmission starting point.

[0153] 10. The method of any preceding clause, wherein sending the one or more packets via the plurality of resources selected within the resource selection window comprises:

[0154] A resource conflict within a channel occupancy time (COT) of the one or more other UEs having reserved resources and having a higher priority transmission than the first UE is detected.

[0155] 11. A method according to any of the preceding clauses, further comprising:

[0156] The transmission from the first UE to the second UE is abandoned at least T time slots before starting the higher priority transmission.

[0157] 12. A method according to any of the preceding clauses, further comprising:

[0158] signaling COT sharing of resources from the first UE to the one or more other UEs having the higher priority transmission having resources reserved within the COT; and

[0159] The one or more packets are sent from the first UE to the second UE via frequency resources that do not overlap with the one or more other UEs.

[0160] 13. A method according to any of the preceding clauses, wherein signaling the COT sharing comprises identifying a destination identity of the first UE within a Sidelink Control Information (SCI) message.

[0161] 14. A method according to any of the preceding clauses, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs are within T time slots of the multiple resources selected by the first UE, wherein the value of T is determined based on each UE or each reservation.

[0162] 15. An apparatus for wireless communication by a first user equipment (UE), the apparatus comprising:

[0163] Memory; and

[0164] a processor coupled to the memory and configured to:

[0165] selecting a plurality of resources within a resource selection window for communication from the first UE to a second UE, wherein the plurality of resources are selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and wherein the plurality of resources selected by the first UE have at least partially overlapping frequency resources reserved by the one or more other UEs;

[0166] performing a listen before talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE; and

[0167] Based on the successful completion of the LBT procedure, one or more packets are sent from the first UE to the second UE via the multiple resources selected within the resource selection window.

[0168] 16. An apparatus according to clause 15, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE and a second start time for the higher priority transmission by one or more additional UEs in the shared channel are no earlier than one time slot.

[0169] 17. An apparatus according to any of the preceding clauses, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE in the shared channel and a second start time for the one or more additional UEs to perform the higher priority transmission are aligned within a time slot.

[0170] 18. An apparatus according to any of the preceding clauses, wherein the processor configured to send the one or more packets through the plurality of resources selected within the resource selection window based on successful completion of the LBT procedure is further configured to:

[0171] The one or more packets having a modification to the selection of the multiple resources within the resource selection window are sent based on the LBT procedure identifying an overlapping frequency resource conflict due to a reservation by another UE, wherein the other UE has a higher priority service than the one or more packets scheduled for transmission by the first UE to the second UE.

[0172] 19. An apparatus as described in any of the preceding clauses, wherein the modification of the selection of the plurality of resources comprises modifying the one or more packets to accommodate the resource conflict within a preemption window.

[0173] 20. An apparatus according to any of the preceding clauses, wherein the processor configured to modify the one or more packets is further configured to:

[0174] Before the first UE executes the LBT procedure, multiple different versions of the one or more packets to be sent are generated at the first UE, so that the first UE can select one of the different versions of the one or more packets to be sent that adapts to the resource conflict.

[0175] 21. An apparatus according to any of the preceding clauses, wherein the partially overlapping frequency resources include overlapping LBT bandwidth required for the one or more other UEs to complete the LBT procedure or one or both of overlapping sub-channels of the multiple resources selected as the first UE.

[0176] 22. An apparatus according to any of the preceding clauses, wherein selecting the plurality of resources within the resource selection window for communication from the first UE to the second UE comprises selecting sub-slot transmission starting points for the plurality of resources selected for the first UE.

[0177] 23. An apparatus as described in any of the preceding clauses, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs indicate a sub-slot starting point.

[0178] 24. An apparatus according to any of the preceding clauses, wherein the processor configured to send the one or more packets through the plurality of resources selected within the resource selection window is further configured to:

[0179] A resource conflict within a channel occupancy time (COT) of the one or more other UEs having reserved resources and having a higher priority transmission than the first UE is detected.

[0180] 25. An apparatus according to any of the preceding clauses, wherein the processor is configured to:

[0181] The transmission from the first UE to the second UE is abandoned at least T time slots before starting the higher priority transmission.

[0182] 26. An apparatus according to any of the preceding clauses, wherein the processor is configured to:

[0183] signaling COT sharing of resources from the first UE to the one or more other UEs having the higher priority transmission having resources reserved within the COT; and

[0184] The one or more packets are sent from the first UE to the second UE via frequency resources that do not overlap with the one or more other UEs.

[0185] 27. An apparatus according to any of the preceding clauses, wherein signaling the COT sharing comprises identifying a destination identity of the first UE within a sidelink control information (SCI) message.

[0186] 28. An apparatus according to any of the preceding clauses, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs are within T time slots of the multiple resources selected by the first UE, wherein the value of T is determined on a per-UE or per-reservation basis.

[0187] 29. A non-transitory computer readable medium storing instructions executable by a processor for wireless communication, the non-transitory computer readable medium comprising instructions for:

[0188] A plurality of resources are selected within a resource selection window for communication from a first user equipment (UE) to a second UE, wherein

[0189] selecting the plurality of resources within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and wherein the plurality of resources selected by the first UE have at least partially overlapping frequency resources reserved by the one or more other UEs;

[0190] performing a listen before talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE; and

[0191] Based on the successful completion of the LBT procedure, one or more packets are sent from the first UE to the second UE via the multiple resources selected within the resource selection window.

[0192] 30. An apparatus for wireless communication, the apparatus comprising:

[0193] means for selecting a plurality of resources within a resource selection window for communication from a first user equipment (UE) to a second UE, wherein the plurality of resources are selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and wherein the plurality of resources selected by the first UE have at least partially overlapping frequency resources reserved by the one or more other UEs;

[0194] means for performing a listen-before-talk (LBT) procedure at the first UE prior to initiating transmission from the first UE to the second UE; and

[0195] Means for sending one or more packets from the first UE to the second UE via the plurality of resources selected within the resource selection window based on successful completion of the LBT procedure.

[0196] Although the foregoing disclosure discusses illustrative aspects and / or embodiments, it should be noted that various changes and modifications may be made herein without departing from the described aspects and / or embodiments as defined by the appended claims. Furthermore, although elements of the described aspects and / or embodiments are described or claimed in the singular, the plural is also contemplated unless limitation to the singular is explicitly stated. Additionally, all or part of any aspect and / or embodiment may be used with all or part of any other aspect and / or embodiment unless otherwise stated.

[0197] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is merely an illustration of the exemplary method. It should be understood that the specific order or hierarchy of the blocks in the process / flowchart can be rearranged based on design preferences. In addition, some blocks can be combined or omitted. The attached method claims provide the elements of each block in a sample order, but are not meant to be limited to the specific order or hierarchy provided.

[0198] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but to conform to the full scope consistent with the language claims, wherein the elements mentioned in the singular are not intended to represent "one and only one", unless specifically so stated, but "one or more". Terms such as "if", "when ..." and "while ..." should be interpreted as "under the conditions of ...", rather than meaning an instantaneous time relationship or reaction. That is, these phrases, such as "when ...", do not mean an instantaneous action in response to the occurrence of an action or during the occurrence of an action, but only mean that if the conditions are met, the action will occur without a specific or instantaneous time constraint to cause the action to occur. The word "exemplary" is used herein to mean "used as an example, instance, or illustration". Any aspect described as "exemplary" herein is not necessarily interpreted as being preferred or having an advantage over other aspects. Unless otherwise specified, the term "some" refers to one or more. Combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” include any combination of A, B, and / or C, which may include multiple A, multiple B, or multiple C. Specifically, combinations such as “at least one of A, B, or C,” “one or more of A, B, or C,” “at least one of A, B, and C,” “one or more of A, B, and C,” and “A, B, C, or any combination thereof” may be only A, only B, only C, A and B, A and C, B and C, or A and B and C, where any such combination may include one or more members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout the disclosure that are known or later become known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is explicitly recited in the claims. Words such as "module," "mechanism," "element," and "device" cannot replace the word "component." Therefore, no claim element will be construed as a part-plus-function unless the element is explicitly stated using the phrase "component for..."

Claims

1. A method for wireless communication, the method comprising: selecting a plurality of resources within a resource selection window for communication from a first user equipment (UE) to a second UE, wherein the plurality of resources are selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and wherein the plurality of resources selected by the first UE have at least partially overlapping frequency resources reserved by the one or more other UEs; performing a listen before talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE; as well as Based on the successful completion of the LBT procedure, one or more packets are sent from the first UE to the second UE via the multiple resources selected within the resource selection window.

2. The method according to claim 1, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE in the shared channel and a second start time for the one or more other UEs to transmit with the higher priority are no earlier than one time slot.

3. The method according to claim 1, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE in the shared channel and a second start time for the one or more other UEs to perform the higher priority transmission are aligned within a time slot.

4. The method of claim 1 , wherein based on successful completion of the LBT procedure, sending the one or more packets through the plurality of resources selected within the resource selection window comprises: The one or more packets having a modification to the selection of the multiple resources within the resource selection window are sent based on the LBT procedure identifying an overlapping frequency resource conflict due to a reservation by another UE, wherein the other UE has a higher priority service than the one or more packets scheduled for transmission by the first UE to the second UE.

5. The method of claim 4, wherein the modification of the selection of the plurality of resources comprises modifying the one or more packets to accommodate the overlapping frequency resource conflict.

6. The method of claim 5, wherein modifying the one or more packages comprises: Before the first UE executes the LBT procedure, multiple different versions of the one or more packets to be sent are generated at the first UE, so that the first UE can select one of the different versions of the one or more packets to be sent that adapts to the overlapping frequency resource conflict.

7. The method according to claim 1, wherein the partially overlapping frequency resources include overlapping LBT bandwidth required for the one or more other UEs to complete the LBT procedure or one or both of overlapping sub-channels of the multiple resources selected as the first UE.

8. The method of claim 1, wherein selecting the plurality of resources within the resource selection window for communication from the first UE to the second UE comprises selecting a subslot transmission starting point for the plurality of resources selected for the first UE.

9. The method of claim 1, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs indicate a sub-slot transmission starting point.

10. The method of claim 1, wherein sending the one or more packets through the plurality of resources selected within the resource selection window comprises: A resource conflict within a channel occupancy time (COT) of the one or more other UEs having reserved resources and having a higher priority transmission than the first UE is detected.

11. The method according to claim 10, further comprising: The transmission from the first UE to the second UE is abandoned at least T time slots before starting the higher priority transmission.

12. The method according to claim 10, further comprising: signaling COT sharing of resources from the first UE to the one or more other UEs having the higher priority transmission having resources reserved within the COT; as well as The one or more packets are sent from the first UE to the second UE via frequency resources that do not overlap with the one or more other UEs.

13. The method of claim 12, wherein signaling the COT sharing comprises identifying a destination identity of the first UE within a sidelink control information (SCI) message.

14. The method of claim 1, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs are within T time slots of the plurality of resources selected by the first UE, wherein the value of T is determined on a per-UE or per-reservation basis.

15. An apparatus for wireless communication by a first user equipment (UE), the apparatus comprising: Memory; and a processor coupled to the memory and configured to: selecting a plurality of resources within a resource selection window for communication from the first UE to a second UE, wherein the plurality of resources are selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and wherein the plurality of resources selected by the first UE have at least partially overlapping frequency resources reserved by the one or more other UEs; performing a listen before talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE; as well as Based on the successful completion of the LBT procedure, one or more packets are sent from the first UE to the second UE via the multiple resources selected within the resource selection window.

16. The apparatus according to claim 15, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE in the shared channel and a second start time for the one or more other UEs to transmit with the higher priority are no earlier than one time slot.

17. The apparatus according to claim 15, wherein the multiple resources within the resource selection window are selected so that a first start time for the first UE to transmit to the second UE in the shared channel and a second start time for the one or more other UEs to perform the higher priority transmission are aligned within a time slot.

18. The apparatus of claim 15, wherein the processor configured to send the one or more packets through the plurality of resources selected within the resource selection window based on successful completion of the LBT procedure is further configured to: The one or more packets having a modification to the selection of the multiple resources within the resource selection window are sent based on the LBT procedure identifying an overlapping frequency resource conflict due to a reservation by another UE, wherein the other UE has a higher priority service than the one or more packets scheduled for transmission by the first UE to the second UE.

19. The apparatus of claim 18, wherein the modification of the selection of the plurality of resources comprises modifying the one or more packets to accommodate the overlapping frequency resource conflict.

20. The apparatus of claim 19, wherein the processor configured to modify the one or more packets is further configured to: Before the first UE executes the LBT procedure, multiple different versions of the one or more packets to be sent are generated at the first UE, so that the first UE can select one of the different versions of the one or more packets to be sent that adapts to the overlapping frequency resource conflict.

21. The apparatus of claim 15, wherein the partially overlapping frequency resources include overlapping LBT bandwidth required for the one or more other UEs to complete the LBT procedure or one or both of overlapping subchannels of the multiple resources selected as the first UE.

22. The apparatus of claim 15, wherein selecting the plurality of resources within the resource selection window for communication from the first UE to the second UE comprises selecting a subslot transmission starting point for the plurality of resources selected for the first UE.

23. The apparatus of claim 15, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs indicate a subslot starting point.

24. The apparatus of claim 15, wherein the processor configured to send the one or more packets through the plurality of resources selected within the resource selection window is further configured to: A resource conflict within a channel occupancy time (COT) of the one or more other UEs having reserved resources and having a higher priority transmission than the first UE is detected.

25. The apparatus of claim 24, wherein the processor is configured to: The transmission from the first UE to the second UE is abandoned at least T time slots before starting the higher priority transmission.

26. The apparatus of claim 24, wherein the processor is configured to: signaling COT sharing of resources from the first UE to the one or more other UEs having the higher priority transmission having resources reserved within the COT; and The one or more packets are sent from the first UE to the second UE via frequency resources that do not overlap with the one or more other UEs.

27. The apparatus of claim 26, wherein signaling the COT sharing comprises identifying a destination identity of the first UE within a sidelink control information (SCI) message.

28. The apparatus of claim 15, wherein the at least partially overlapping frequency resources reserved by the one or more other UEs are within T time slots of the plurality of resources selected by the first UE, wherein a value of T is determined on a per-UE or per-reservation basis.

29. A non-transitory computer readable medium storing instructions executable by a processor for wireless communication, the non-transitory computer readable medium comprising instructions for: selecting a plurality of resources within a resource selection window for communication from a first user equipment (UE) to a second UE, wherein the plurality of resources are selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and wherein the plurality of resources selected by the first UE have at least partially overlapping frequency resources reserved by the one or more other UEs; performing a listen before talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE; as well as Based on the successful completion of the LBT procedure, one or more packets are sent from the first UE to the second UE via the multiple resources selected within the resource selection window.

30. An apparatus for wireless communication, the apparatus comprising: means for selecting a plurality of resources within a resource selection window for communication from a first user equipment (UE) to a second UE, wherein the plurality of resources are selected within the resource selection window to allow one or more other UEs having a higher priority transmission than the first UE to gain access to a shared channel, and wherein the plurality of resources selected by the first UE have at least partially overlapping frequency resources reserved by the one or more other UEs; means for performing a listen before talk (LBT) procedure at the first UE before initiating transmission from the first UE to the second UE; and Means for sending one or more packets from the first UE to the second UE via the plurality of resources selected within the resource selection window based on successful completion of the LBT procedure.

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