Power-saving congestion control in user equipment used for direct link communication

Abstract

Example implementations include: a method, apparatus, and computer-readable medium for wireless communication via a lateral link between a first user equipment (UE) and a second UE. The first UE can identify a discontinuous reception (DRX) configuration for direct link communication with the second UE. The first UE can determine the CBR by measuring multiple channel busy ratio (CBR) times within a time window preceding direct link transmission based on the DRX configuration. The first UE can determine whether to perform congestion control for the direct link transmission based on the CBR. The first UE can perform direct link transmission subject to channel occupancy limits.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This Patent Application claims priority to U.S. Patent Application No. 17 / 148,000, filed January 13, 2021, for “CONGESTION CONTROL FOR POWER SAVINGS IN USER EQUIPMENT FOR DIRECT LINK COMMUNICATIONS,” assigned to the assignee of the present application, and is hereby expressly incorporated by reference herein in its entirety. TECHNICAL FIELD

[0003] The present disclosure relates generally to communication systems, and more particularly to apparatus and methods for congestion control for power saving user equipment in direct link communications between two devices. BACKGROUND

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems can 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.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of a telecommunication standard is 5G New Radio (NR). 5G NR is a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with 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). Some aspects of 5G NR can be based on the 4G Long Term Evolution (LTE) standard. There are ongoing efforts to improve 5G NR technology, for example by improving the use of resources. SUMMARY

[0006] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate 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 the more detailed description that is presented later.

[0007] In one aspect, the disclosure provides a method of wireless communication for a first user equipment (UE). The method can include identifying a configuration for discontinuous reception (DRX) on a sidelink communication. The method can include determining a plurality of channel busy ratio (CBR) measurement occasions based on the configuration for DRX. The method can include determining a CBR based on measurements of the plurality of CBR measurement occasions.

[0008] The disclosure also provides an apparatus (e.g., a user equipment) including a memory storing computer-executable instructions and at least one processor configured to execute the computer-executable instructions to perform the method above, and a computer-readable medium storing computer-executable instructions to perform the method above.

[0009] In one aspect, the disclosure provides a method of wireless communication for a first user equipment (UE). The method can include identifying a configuration for discontinuous reception (DRX) on a sidelink communication. The method can include determining a plurality of channel busy ratio (CBR) measurement occasions based on the configuration for DRX. The method can include determining a CBR based on measurements of the plurality of CBR measurement occasions.

[0010] The disclosure also provides an apparatus (e.g., a user equipment) including a memory storing computer-executable instructions and at least one processor configured to execute the computer-executable instructions to perform the method above, and a computer-readable medium storing computer-executable instructions to perform the method above.

[0011] For the purposes described above and related, one or more aspects include the features detailed below and specifically pointed out in the claims. The following description and accompanying drawings describe certain exemplary features of one or more aspects. However, these features merely illustrate some of the various methods that can employ the basic principles of these aspects, and the description is intended to include all such aspects and their equivalents. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating an example of a wireless communication system and access network.

[0013] Figure 2A This is a diagram showing an example of the first 5G NR frame.

[0014] Figure 2B This is a diagram illustrating an example of a downlink channel within a 5G NR subframe.

[0015] Figure 2C This is a diagram showing an example of a second 5G NR frame.

[0016] Figure 2D This is a diagram illustrating an example of an uplink channel within a 5G NR subframe.

[0017] Figure 3 This is a diagram illustrating examples of base stations and user equipment (UEs) in an access network.

[0018] Figure 4 This is a diagram illustrating an example of discontinuous reception (DRX) operation for a direct link between a first UE and a second UE.

[0019] Figure 5 This is a diagram illustrating an example of a frequency domain resource switching operation.

[0020] Figure 6 This is a diagram illustrating another example of a frequency domain resource switching operation that includes receiving activation of a second frequency domain resource.

[0021] Figure 7 This is a graph of example channel busy ratio (CBR) measurements based on the UE's DRX configuration.

[0022] Figure 8 This is a graph of example CBR measurements taken at multiple CBR measurement points.

[0023] Figure 9 This is a diagram illustrating an example of a CBR measurement with frequency domain resource switching.

[0024] Figure 10 This is a diagram illustrating an example of resource switching based on CBR measurements.

[0025] Figure 11 This is a diagram illustrating example communication and components of a base station, a first transmitting UE, and a second receiving UE.

[0026] Figure 12 This is a conceptual data flow diagram illustrating the data flow between different units / components in the example UE.

[0027] Figure 13 This is a flowchart of an example method for operating a UE for lateral link transmission with congestion control, based on DRX configuration.

[0028] Figure 14 This is a flowchart of an example method for operating a UE for lateral link transmission with congestion control, based on a frequency domain configuration with multiple frequency domain resources. Detailed Implementation

[0029] The specific embodiments described below with reference to the accompanying drawings are intended merely to describe various configurations and not to indicate that the concepts described herein can be implemented only in these configurations. Specific details are included in the specific embodiments to provide a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be implemented without using these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring these concepts.

[0030] The described features typically relate to congestion control and power savings in direct link communication for device-to-device (D2D) communication technologies. As used herein, a direct link refers to a direct wireless communication path from a first wireless device to a second wireless device. For example, in fifth-generation (5G) new radio (NR) communication technologies, a direct link between two user equipments (UEs) can be referred to as a side link (SL), rather than communication via a Uu interface (e.g., from a gNB to a UE). Direct links can be utilized in D2D communication technologies, which can include vehicle-to-vehicle (V2V) communication, vehicle-to-infrastructure (V2I) communication (e.g., from a vehicle-based communication device to a road infrastructure node), vehicle-to-network (V2N) communication (e.g., from a vehicle-based communication device to one or more network nodes such as a base station), combinations thereof, and / or communication with other devices, collectively referred to as vehicle-to-everything (V2X) communication. In V2X communication, vehicle-based communication devices can communicate with each other and / or with infrastructure devices via a direct link channel.

[0031] One problem with D2D communication is that congestion can occur if multiple devices attempt to communicate directly. D2D communication technologies allow user equipment (UE) to schedule congestion-controlled transmissions. For example, the Channel Busy Ratio (CBR) can be used as a measure of congestion control. CBR estimation can be performed using the Received Signal Strength Indicator (RSSI) for either the side link or the direct link. For instance, the CBR of all sub-channels used for direct link transmissions can be measured within a window before transmission. The UE can then limit the Channel Occupancy Rate (CR) to less than a configured threshold based on the measured CBR.

[0032] Due to the availability of vehicle power or other power sources, D2D communication technologies intended for use within vehicles or infrastructure can disregard power consumption issues. However, D2D communication technologies may also be applied to portable devices, such as mobile devices with limited power sources (e.g., batteries). Therefore, power-saving techniques may be required for D2D communication technologies.

[0033] A UE communicating with another device (e.g., a base station or another UE) can actively monitor control channels (e.g., the Physical Downlink Control Channel (PDCCH) or Physical Sidelink Control Channel (PSCCH)) to obtain authorization for scheduled transmissions. When the UE is not actively receiving data, it can save power by entering Discontinuous Reception (DRX) mode. In DRX mode, the UE monitors the control channel during the active period and the on-duration of the DRX cycle, and can sleep during the off-duration portion of the DRX cycle. That is, the UE can not monitor the control channel during the off-duration portion of the DRX cycle, and the base station can avoid sending control channels to the UE during the off-duration portion of the DRX cycle. Another exemplary power-saving technique is frequency domain resource adaptation, where the UE can switch to smaller frequency domain resources for monitoring when it is not actively transmitting or receiving data.

[0034] Power-saving techniques can potentially interfere with congestion control techniques. Specifically, because power-saving techniques such as DRX and frequency-domain resource adaptation limit the resources that the UE can monitor, the UE may not be able to measure RSSI on all resources used for transmission during the window before transmission.

[0035] In one aspect, this disclosure provides techniques for determining the Congestion Control Ratio (CBR) when one or more power-saving techniques limiting monitored resources are configured. This disclosure provides multiple CBR measurement opportunities that the UE can measure to determine the channel quality metric (e.g., RSSI) used for CBR calculation. Some CBR measurement opportunities can be configured on resources that the UE is not configured to monitor due to power-saving techniques. Therefore, the UE can determine the CBR of resources on which the UE can perform direct link transmissions. When the UE has data to transmit, the UE can immediately schedule direct link transmissions and determine the Congestion Control Ratio (CR) limit for congestion control without performing additional measurements. Therefore, when power-saving techniques are configured, the UE may not incur additional delays for performing congestion control. In one aspect, RSSI measurement can be less complex than monitoring the control channel and occurs less frequently than constant monitoring without power-saving techniques. Therefore, determining the CBR based on CBR measurement opportunities while still implementing power-saving techniques can also reduce power consumption compared to not using power-saving techniques.

[0036] Various apparatuses and methods are now described with reference to some aspects of a telecommunications system. These apparatuses and methods will be described in the following detailed embodiments and depicted in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements”). Such elements can 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.

[0037] For example, an element, any part of an element, or any combination of elements can be implemented as a "processing system" including 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, system-on-a-chip (SoCs), baseband processors, field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, discrete hardware circuitry, and other suitable hardware configured to perform the various functions described throughout this disclosure. One or more processors in a processing system can execute software. Software should be broadly interpreted as meaning instructions, instruction sets, code, code segments, program code, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description languages, or other terms.

[0038] Therefore, in one or more exemplary embodiments, the functionality described herein can be implemented in hardware, software, or any combination thereof. When implemented in software, these functions can be stored or encoded as one or more instructions or codes on a computer-readable medium. A computer-readable medium includes a computer storage medium, which may be referred to as a non-transitory computer-readable medium. A non-transitory computer-readable medium may not include transient signals. The storage medium can be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of computer-readable media of the foregoing types, or any other medium capable of storing computer-executable code in the form of instructions or data structures and accessible to a computer.

[0039] Figure 1 This diagram illustrates an example of a wireless communication system and access network 100. The wireless communication system (also referred to as a Wireless Wide Area Network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). Base station 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 femtocells, picocells, and microcells.

[0040] In one aspect, one or more of UEs 104 may include a lateral link CBR component 140 that performs congestion control for lateral link communication configured with power-saving techniques (e.g., DRX or frequency domain resource adaptation). The lateral link CBR component 140 may include a configuration component 142 that identifies a DRX configuration for direct link communication with the second UE. In one aspect, the configuration component 142 may identify a first frequency domain resource and a second frequency domain resource with attached configuration for direct link communication with the second UE. The lateral link CBR component 140 may include a measurement component 144 that determines the CBR based on the DRX configuration and multiple CBR measurement opportunities within a time window prior to direct link transmission. In one aspect, the measurement component 144 may be configured to measure the RSSI on the second frequency domain resource during multiple CBR measurement opportunities within a time window prior to direct link transmission on the second frequency domain resource when the second frequency domain resource is inactive. The measurement component 144 may determine the CBR of the second frequency domain resource based on the RSSI of the multiple CBR measurement opportunities. The lateral link CBR component 140 may include a congestion controller 146, which determines whether to perform congestion control on direct link transmissions based on the CBR. The lateral link CBR component 140 may include a transmission component 148, which performs direct link transmissions subject to channel occupancy limitations.

[0041] In one aspect, one or more of the base stations 102 may include a lateral link configuration component 198 configured to configure DRX configuration, frequency domain resource configuration, and / or CBR timing configuration to a first UE.

[0042] Base station 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can interact with EPC 160 via a first backhaul link 132 (e.g., S1 interface), where the first backhaul link 132 can be a wired link or a wireless link. Base station 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN)) can interact with core network 190 via a second backhaul link 184, where the second backhaul link 184 can be a wired link or a wireless link. In addition to other functions, base station 102 may perform one or more of the following functions: transmission of user data, encryption and decryption of radio channels, 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), user and device tracking, RAN Information Management (RIM), paging, location, and transmission of alarm messages. Base stations 102 may communicate directly or indirectly with each other via a third backhaul link 134 (e.g., an X2 interface) (e.g., via EPC 160 or core network 190). The third backhaul link 134 may be wired or wireless.

[0043] Base station 102 can wirelessly communicate with UE 104. Each of base stations 102 can provide communication coverage for a corresponding geographic coverage area 110. Overlapping geographic coverage areas 110 may exist. For example, small cell 102' may have a coverage area 110' that overlaps with the coverage areas 110 of one or more macro base stations 102. A network including small cells and macro cells can be referred to as a heterogeneous network. In addition, a heterogeneous network may also include home node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between base station 102 and UE 104 may include uplink (UL) (also referred to as reverse link) transmission from UE 104 to base station 102 and / or downlink (DL) (also referred to as forward link) transmission from base station 102 to UE 104. The communication link 120 may use multiple-input multiple-output (MIMO) antenna technology, which includes spatial multiplexing, beamforming, and / or transmit diversity. These communication links may be via one or more carriers. Base station 102 / UE 104 can use up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) of bandwidth for each carrier allocated in carrier aggregation for transmission in each direction, totaling up to Yx MHz (x component carriers). These carriers can be adjacent to each other or not. Carrier allocation can be asymmetric with respect to DL and UL (e.g., more or fewer carriers can be allocated to DL compared to UL). These component carriers can include primary component carriers and one or more secondary component carriers. The primary component carrier can be referred to as the primary cell (PCell), and the secondary component carriers can be referred to as secondary cells (SCells).

[0044] Some UEs 104 can communicate with each other using device-to-device (D2D) communication link 158. D2D communication link 158 can use DL / UL WWAN spectrum. D2D communication link 158 can use one or more side link channels, such as Physical Side Link Broadcast Channel (PSBCH), Physical Side Link Discovery Channel (PSDCH), Physical Side Link Shared Channel (PSSCH), and Physical Side Link Control Channel (PSCCH). D2D communication can be performed through various wireless D2D communication systems, such as FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR. In one aspect, D2D communication link 158 can be configured with direct link carrier aggregation for multiple component carriers.

[0045] The wireless communication system may also include a Wi-Fi access point (AP) 150, which communicates with a Wi-Fi station (STA) 152 via a communication link 154 in the 5 GHz unlicensed spectrum. When communicating in the unlicensed spectrum, the STA 152 / AP 150 may perform a free channel assessment (CCA) before communication to determine whether the channel is available.

[0046] Small cell 102' can operate in licensed and / or unlicensed spectrum. When operating in unlicensed spectrum, small cell 102' can employ NR and use the same 5 GHz unlicensed spectrum as Wi-Fi AP 150. Small cell 102' employing NR in unlicensed spectrum can improve access network coverage and / or increase access network capacity.

[0047] 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 names FR1 (410MHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). The frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Although a portion of FR1 is greater than 6GHz, in various documents and articles, FR1 is often (interchangeably) referred to as the "below 6GHz" band. Similar naming issues sometimes arise with FR2, although it differs from the Extremely High Frequency (EHF) band (30GHz-300GHz) as defined by the International Telecommunication Union (ITU) as a "millimeter wave" (mmW) band, it is often (interchangeably) referred to as the "millimeter wave" band in various documents and articles.

[0048] In light of the foregoing, unless otherwise explicitly stated, it should be understood that the terms "below 6 GHz," etc. (if used herein), can broadly refer to frequencies below 6 GHz, which may be within FR1 or include intermediate frequency band frequencies. Furthermore, unless otherwise explicitly stated, it should be understood that the terms "millimeter wave," etc. (if used herein), can broadly refer to frequencies including intermediate frequency band frequencies, which may be within FR2 or within the EHF band. Communication using millimeter wave radio bands suffers from extremely high path loss and short communication range. The mmW base station 180 can utilize beamforming 182 with the UE 104 to compensate for this path loss and short communication range.

[0049] Base station 180 may transmit beamformed signals to UE 104 in one or more transmit directions 182'. 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 optimal receive and transmit directions for each of base station 180 / UE 104. The transmit and receive directions of base station 180 may be the same or different. The transmit and receive directions of UE 104 may be the same or different.

[0050] EPC 160 may include Mobility Management Entity (MME) 162, other MMEs 164, Serving Gateway 166, Multimedia Broadcast Multicast Service (MBMS) Gateway 168, Broadcast Multicast Service Center (BM-SC) 170, and Packet Data Network (PDN) Gateway 172. MME 162 can communicate with Home Subscriber Server (HSS) 174. MME 162 is the control node that handles signaling between UE 104 and EPC 160. Typically, MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through Serving Gateway 166, which is itself connected to PDN Gateway 172. PDN Gateway 172 provides UE IP address allocation and other functions. PDN Gateway 172 and BM-SC 170 are connected to IP Service 176. IP Service 176 may include the Internet, intranet, IP Multimedia Subsystem (IMS), and PS streaming services and / or other IP services. The BM-SC 170 can provide functions for MBMS user service provisioning and delivery. The BM-SC 170 can serve as an entry point for content provider MBMS transmissions, can be used to authorize and initiate MBMS bearer services in the Public Land Mobile Network (PLMN), and can be used to schedule MBMS transmissions. The MBMS gateway 168 can be used to distribute MBMS services to base stations 102 belonging to the Multicast-Broadcast Single Frequency Network (MBSFN) area belonging to the Broadcast-Specific Service, and can be responsible for session management (start / stop) and collection of billing information related to eMBMS.

[0051] Core network 190 may include Access and Mobility Management Function (AMF) 192, other AMFs 193, Session Management Function (SMF) 194, and User Plane Function (UPF) 195. AMF 192 can communicate with Unified Data Management (UDM) 196. AMF 192 is the control node that handles signaling between UE 104 and core network 190. Typically, AMF 192 provides QoS streaming and session management. All user Internet Protocol (IP) packets are transmitted through UPF 195. UPF 195 provides UE IP address allocation and other functions. UPF 195 connects to IP service 197. IP service 197 may include the Internet, intranet, IP Multimedia Subsystem (IMS), PS streaming service, and / or other IP services.

[0052] Base stations may include and / or be referred to as gNB, Node B, eNB, access point, base transceiver, radio base station, radio transceiver, transceiver function, Basic Services Set (BSS), Extended Services Set (ESS), Transmitter Receiver Point (TRP), or some other suitable term. Base station 102 provides UE 104 with access to EPC 160 or core network 190. Examples of UE 104 include cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal digital assistants (PDAs), satellite radios, GPS devices, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, tablet devices, smart devices, wearable devices, vehicles, electricity meters, air pumps, large or small kitchen appliances, medical devices, implants, sensors / actuators, displays, or any other similar functional devices. Some of UE 104 may be referred to as IoT devices (e.g., parking meters, air pumps, toasters, vehicles, heart monitors, etc.). UE 104 may also be referred to as a station, mobile station, user station, mobile unit, user unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile user station, access terminal, mobile terminal, radio terminal, remote terminal, handheld device, user agent, mobile client, client, or any other suitable term.

[0053] Although the following description focuses on 5G NR, the concepts described herein can be applied to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

[0054] Figure 2A Figure 200 shows an example of the first subframe in a 5G / NR frame structure. Figure 2B Figure 230 shows an example of a DL channel in a 5G / NR subframe. Figure 2CFigure 250 shows an example of the second subframe in a 5G / NR frame structure. Figure 2D Figure 280 illustrates an example of a UL channel in a 5G / NR subframe. This 5G / NR frame structure can be either Frequency Division Duplex (FDD) or Time Division Duplex (TDD). In the FDD case, for a specific set of subcarriers (carrier system bandwidth), subframes within that set are dedicated to either DL or UL. In the TDD case, for a specific set of subcarriers (carrier system bandwidth), subframes within that set are dedicated to both DL and UL. Figure 2A , 2C In the provided example, the 5G / NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (primarily DL), where D is DL, U is UL, and X is used flexibly between DL and UL, and subframe 3 is configured with slot format 34 (primarily UL). Although subframes 3 and 4 are shown with slot formats 34 and 28 respectively, any particular subframe can be configured with any of the various available slot formats 0-61. Slot formats 0 and 1 are full DL and UL, respectively. Other slot formats 2-61 include a mixture of DL, UL, and flexible symbols. The slot format is configured for the UE via the received Slot Format Indicator (SFI) (dynamically configured via DL Control Information (DCI) or semi-static / static configured via Radio Resource Control (RRC) signaling). It should be noted that the following description also applies to TDD 5G / NR frame structures.

[0055] Other wireless communication technologies may have different frame structures and / or different channels. A frame (10 ms) can be divided into 10 subframes (1 ms) of the same size. Each subframe may include one or more time slots. Subframes may also include micro-slots, which may include 7, 4, or 2 symbols. Depending on the time slot configuration, each time slot may include 7 or 14 symbols. For time slot configuration 0, each time slot may include 14 symbols, while for time slot configuration 1, each time slot may include 7 symbols. Symbols on the DL can be Cyclic Prefix (CP) OFDM (CP-OFDM) symbols. Symbols on the UL can be CP-OFDM symbols (for high-throughput scenarios) or Discrete Fourier Transform (DFT) Extended OFDM (DFT-s-OFDM) symbols (also known as Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols) (for power-constrained scenarios; limited to single-stream transmission). The number of time slots within a subframe is based on the time slot configuration and parameter set. For slot configuration 0, different parameter sets μ0 to 5 allow each subframe to have 1, 2, 4, 8, 16, and 32 slots, respectively. For slot configuration 1, different parameter sets 0 to 2 allow each subframe to have 2, 4, and 8 slots, respectively. Therefore, for slot configuration 0 and parameter set μ, there are 14 symbols / slots and 2... μEach time slot / subframe. Subcarrier spacing and symbol length / duration depend on the parameter set. Subcarrier spacing can be equal to 2. μ *15kHz, where μ is the parameter set from 0 to 5. Thus, the subcarrier spacing is 15kHz for parameter set μ = 0, and 480kHz for parameter set μ = 5. The symbol length / duration is inversely proportional to the subcarrier spacing. Figures 2A-2D Examples are provided for slot configuration 0 with 14 symbols per slot and parameter set μ=2 with 4 slots per subframe. The slot duration is 0.25ms, the subcarrier spacing is 60kHz, and the symbol duration is approximately 16.67μs.

[0056] The frame structure is represented using a resource grid. Each time slot consists of a resource block (RB) extending for 12 consecutive subcarriers (also known as a physical RB (PRB)). The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0057] like Figure 2A As shown, some of the REs carry reference (pilot) signals (RS) for the UE. This RS may include a demodulation RS (DM-RS) (indicated as R for a particular configuration). x (where 100x is the port number, but other DM-RS configurations are also possible) and the Channel State Information Reference Signal (CSI-RS) for channel estimation at the UE. RS may also include Beam Measurement RS (BRS), Beam Refinement RS (BRRS), and Phase Tracking RS (PT-RS).

[0058] Figure 2BExamples of various DL channels in a subframe of a frame are shown. The Physical Downlink Control Channel (PDCCH) carries the DCI in one or more Control Channel Elements (CCEs), each CCE comprising nine RE Groups (REGs), each REG comprising four consecutive REs in an OFDM symbol. The Primary Synchronization Signal (PSS) may be located in symbol 2 of a specific subframe of the frame. UE 104 uses the PSS to determine subframe / symbol timing and physical layer identifiers. The Secondary Synchronization Signal (SSS) may be located in symbol 4 of a specific subframe of the frame. The UE uses the SSS to determine the Physical Layer Cell Identifier Group Number and radio frame timing. Based on the Physical Layer Identifier and Physical Layer Cell Identifier Group Number, the UE can determine the Physical Cell Identifier (PCI). Based on the PCI, the UE can determine the location of the aforementioned DM-RS. The Physical Broadcast Channel (PBCH) carrying the Primary Information Block (MIB) can be logically combined with the PSS and SSS to form a Synchronization Signal (SS) / PBCH block. 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 (e.g., System Information Block (SIB)) that is not transmitted via the PBCH, and paging messages.

[0059] like Figure 2C As shown, some REs carry DM-RS (indicated as R for a specific configuration, but other DMRS configurations are also possible) for channel estimation at the base station. The UE can transmit DM-RS for the Physical Uplink Control Channel (PUCCH) and DM-RS for the Physical Uplink Shared Channel (PUSCH). PUSCH DM-RS can be transmitted in the first one or two symbols before the PUSCH. PUCCH DM-RS can be transmitted in different configurations depending on whether a short or long PUCCH is transmitted and the specific PUCCH format used. The UE can transmit a Sounding Reference Signal (SRS). SRS can be transmitted in the last symbol of a subframe. SRS can have a comb structure, and the UE can transmit SRS on one of these comb structures. The base station can use SRS for channel quality estimation to implement frequency-dependent scheduling on the UL.

[0060] Figure 2D Examples of various UL channels in a subframe of a frame are shown. The PUCCH can be located as indicated in one configuration. The PUCCH carries uplink control information (UCI) such as scheduling requests, channel quality indicators (CQI), precoding matrix indicators (PMI), rank indicators (RI), and HARQ ACK / NACK feedback. The PUSCH carries data, and can also be used to carry buffer status reports (BSR), power clearance reports (PHR), and / or UCI.

[0061] Figure 3 This is a block diagram illustrating the communication between base station 310 and UE 350 in the access network. In the DL (Data Link Module), IP packets from EPC 160 are provided to controller / processor 375. Controller / processor 375 implements Layer 3 and Layer 2 functions. Layer 3 includes the Radio Resource Control (RRC) layer, and Layer 2 includes the Serving Data Adaptation Protocol (SDAP) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer. The controller / processor 375 provides: RRC layer functions associated with broadcasting system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), movement between radio access technologies (RATs), and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with upper-layer packet data unit (PDU) transmission, error correction via ARQ, connection, segmentation, and reassembly of RLC service data units (SDUs), resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing MAC SDUs onto transport blocks (TBs), demultiplexing MAC SDUs from TBs, scheduling information reporting, error correction via HARQ, priority processing, and logical channel priority allocation.

[0062] Transmit (TX) processor 316 and receive (RX) processor 370 implement Layer 1 functions associated with various signal processing functions. Layer 1, including the physical (PHY) layer, may include error detection of the transport channel, forward error correction (FEC) encoding / decoding of the transport channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. TX processor 316 processes the mapping for the signal constellation based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase phase shift keying (M-PSK), and M-order quadrature amplitude modulation (M-QAM)). The encoded and modulated symbols can then be segmented into parallel streams. Each stream can then be mapped to OFDM subcarriers, multiplexed with a reference signal (e.g., a pilot) in the time and / or frequency domains, and subsequently combined using an inverse Fourier transform (IFFT) to generate a physical channel carrying a stream of time-domain OFDM symbols. The OFDM stream is spatially precoded to generate multiple spatial streams. Channel estimates from channel estimator 374 can be used to determine coding and modulation schemes and to implement spatial processing. The channel estimates can be derived from reference signals and / or channel condition feedback transmitted by UE 350. Subsequently, each spatial stream can be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX can use the respective spatial stream to modulate an RF carrier for transmission.

[0063] At UE 350, each receiver 354RX receives signals through its respective antenna 352. Each receiver 354RX recovers the information modulated onto the RF carrier and provides this information to the receive (RX) processor 356. The TX processor 368 and RX processor 356 implement Layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial streams destined for UE 350. If multiple spatial streams are destined for UE 350, the RX processor 356 can combine them into a single OFDM symbol stream. Subsequently, the RX processor 356 uses a Fast Fourier Transform (FFT) to transform the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, along with the reference signal, are recovered and demodulated by determining the most probable signal constellation points transmitted by base station 310. These soft decisions can be based on channel estimates calculated by channel estimator 358. These soft decisions are then decoded and deinterleaved to recover the data and control signals originally transmitted by base station 310 on the physical channel. This data and control signals are then provided to controller / processor 359, which implements Layer 3 and Layer 2 functions.

[0064] The controller / processor 359 can be associated with a memory 360 that stores program code and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller / processor 359 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0065] Similar to the functions described in the DL transmission combined with base station 310, controller / processor 359 provides: RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with upper-layer PDU transmission, error correction via ARQ, RLC SDU connection, segmentation and reassembly, RLC data PDU resegmentation, and RLC data PDU reordering; and MAC layer functions associated with mapping between logical channels and transport channels, MAC SDU multiplexing onto TB, demultiplexing MAC SDU from TB, scheduling information reporting, error correction via HARQ, priority processing, and logical channel priority allocation.

[0066] The channel estimate derived by channel estimator 358 from the reference signal or feedback transmitted by base station 310 can be used by TX processor 368 to select appropriate coding and modulation schemes and facilitate spatial processing. The spatial stream generated by TX processor 368 can be provided to different antennas 352 via their respective transmitters 354TX. Each transmitter 354TX can use its own spatial stream to modulate an RF carrier for transmission.

[0067] Base station 310 processes UL transmissions in a manner similar to that described in conjunction with the receiver function at UE 350. Each receiver 318RX receives signals via its respective antenna 320. Each receiver 318RX recovers the information modulated onto the RF carrier and provides that information to RX processor 370.

[0068] The controller / processor 375 can be associated with a memory 376 that stores program code and data. The memory 376 can be referred to as a computer-readable medium. In the UL, the controller / processor 375 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport and logical channels to recover IP packets from the UE 350. IP packets from the controller / processor 375 can be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operation.

[0069] At least one of the TX processor 368, RX processor 356, and controller / processor 359 can be configured to perform operations related to... Figure 1 Aspects related to the lateral link CBR component 140.

[0070] At least one of the TX processor 316, RX processor 370, and controller / processor 375 can be configured to perform operations related to... Figure 1 The lateral link configuration component 198 is related to this aspect.

[0071] Figure 4 Figure 400 illustrates an example of DRX operation for a direct link between a first device 404 (e.g., UE 104) and a second device 406 (e.g., another UE such as an IoT device). As shown, this direct link can provide, for example, unicast communication (i.e., direct communication between UE1 and UE2). Direct link communication can also be applied to other broadcast types (e.g., multicast and broadcast). For example, in the case of broadcast, UE1 can send to all nearby UEs without knowing the identity of each UE. In the frequency domain, the direct link can be on resource pool 410. In the time domain, the DRX configuration can define a DRX period including a DRX on duration 422 and a DRX off duration 424. The DRX configuration can provide power savings by allowing UE 104 to sleep during the DRX off duration. In other words, UE 104 can not monitor the direct link control or data channel during the DRX off duration 424.

[0072] In one aspect, in addition to DRX operation, a wake-up signal (WUS) operation for the direct link between the first device (e.g., UE 104) and the second device can also be configured. The WUS configuration can define a WUS monitoring period 430, which can be the same as the DRX period 420. At the start of the WUS period 430, UE 104 can monitor resource pool 410 for WUS 432. If WUS 432 is detected, UE 104 can remain awake for the remainder of the DRX on duration 422 and then sleep during the DRX off duration 424, as described above. If WUS 432 is not detected, UE 104 can sleep for the remainder of the WUS monitoring period 430. That is, if WUS 432 is not detected, UE 104 may not enter the DRX on duration 422.

[0073] Figure 5 Figure 500 illustrates an example of frequency domain resource handover. "Frequency domain resource" can refer to any identifier of resource allocation in the frequency domain, such as a bandwidth portion (BWP), resource pool, or component carrier. Frequency domain resource handover can provide power savings by switching the UE to a smaller frequency domain resource based on transmit / receive load. For example, UE 104 can be configured with a first frequency domain resource 510 and a second frequency domain resource 512. The second frequency domain resource 512 can be larger than the first frequency domain resource 510. In some implementations, the first frequency domain resource 510 can be a subset of the second frequency domain resource 512. In one aspect, UE 104 can be configured with direct link carrier aggregation, where UE 104 is configured with multiple component carriers. Each component carrier can be configured with one or more frequency domain resources.

[0074] First frequency domain resource 510 may be active, for example, in time slot 520. UE 104 may receive a small amount of data 522 from a higher layer and transmit the small amount of data 522 via first frequency domain resource 510. For example, the small amount of data 522 may be smaller than the maximum transport block size of first frequency domain resource 510. If a large amount of data 532 (e.g., larger than the maximum transport block size of first frequency domain resource 510) arrives from a higher layer in time slot 530, UE 104 may switch to second frequency domain resource 512. After a switching time 534, UE 104 may transmit the large amount of data 532 on second frequency domain resource 512 in one or more time slots 540, where switching time 534 may be zero or more time slots. If UE 104 does not receive data from a higher layer or receives a small amount of data during duration 550, UE 104 may switch to first frequency domain resource 510 after a switching time 552 (e.g., zero or more time slots) for use in subsequent time slots 560.

[0075] Figure 6 Figure 600 illustrates another example of frequency domain resource switching by receiving activation of a second frequency domain resource. In this example, UE 104 may be configured with a first frequency domain resource 610 and a second frequency domain resource 612. UE 104 may receive side link control information (SCI) 620 on the first frequency domain resource 610 that schedules a physical side link shared channel (PSSCH) 622. SCI 620 and / or PSSCH 622 may activate the second frequency domain resource 612. For example, the PSSCH may include a media access control (MAC) control element (MAC-CE) that activates the second frequency domain resource 612. UE 104 may then receive a second SCI 630 that schedules PSSCH 632 on the first frequency domain resource 610 and / or PSSCH 634 on the second frequency domain resource 612. The second SCI 630, PSSCH 632, and / or PSSCH 634 may deactivate the second frequency domain resource 612. Therefore, the second frequency domain resource 612 can be dynamically activated and deactivated as needed. UE 104 can save power by not monitoring the deactivated second frequency domain resource 612.

[0076] In one respect, for any of the DRX configuration, WUS configuration, or frequency domain resource handover, the UE may need to spend a significant amount of time in sleep mode to conserve power for at least some resources. Direct link communication may include congestion control. For example, the Channel Busy Ratio (CBR) can be used as a metric for congestion control. UE 104 can measure the CBR to determine if the medium is busy, and UE 104 can limit its resource utilization based on the measured CBR by limiting the Channel Occupancy Rate (CR) to less than a configured threshold. A conventional definition of CBR could be based on the Received Signal Strength Indicators (RSSI) of all subchannels during the time period of [n-100, n-1] time slots prior to the start of transmission at time slot n. In one respect, since UE 104 can schedule direct link transmissions as data becomes available, a conventionally defined CBR measurement could mean that UE 104 needs to continuously measure the CBR to have a valid CBR measurement at time slot n. If the UE continuously measures RSSI to determine the CBR, the UE may not be able to utilize power-saving techniques such as DRX and WUS. Similarly, for frequency domain power savings, traditional CBR measurements can prevent the UE from switching to frequency domain resources with smaller bandwidths due to monitoring of all frequency domain resources in the CBR.

[0077] Figure 7Figure 700 shows CBR measurement based on the DRX configuration of UE 104. UE 104 can be configured with a DRX period 420 including a DRX on duration 422 and a DRX off duration 424. Multiple CBR measurement opportunities 712 can be defined based on the DRX period 420. For example, CBR can be defined as the channel busy ratio (i.e., SL-RSSI > threshold) measured at CBR measurement opportunity 712 during the DRX on duration 422 within a measurement window 710 preceding a transmission slot 720 (e.g., slot n). The measurement window 710 can be a time period of [n-100, n-1], or it can be extended. For example, the measurement window 710 can include multiple slots within the DRX on duration, which is equal to the duration of the time period [n-100, n-1] (i.e., 100 slots). If UE 104 is configured to monitor WUS, UE 104 can measure CBR only during the DRX on duration during UE wake-up. In other words, the CBR can be defined using the time slot when the UE is in wake-up state (determined by both DRX and WUS). In one respect, this definition of CBR may be more efficient when the DRX configurations of multiple UEs are aligned. For example, for two pairs of communicating UEs, the DRX on-duration durations 422 can be either completely overlapping or completely orthogonal. In the case of overlapping DRX on-duration durations, the CBR measurement during the DRX on-duration duration can accurately indicate the congestion that may be experienced during transmission. In the case of orthogonal DRX on-duration durations, although the CBR measurement may not include transmissions of another pair of UEs, such transmissions may not cause congestion during the DRX on-duration duration.

[0078] Figure 8This is a schematic diagram 800 illustrating CBR measurements over multiple CBR measurement opportunities 810. UE 104 can be configured with a DRX cycle 420 including a DRX on duration 422 and a DRX off duration 424. UE 104 can be configured to have multiple CBR measurement opportunities 810. The configuration of the CBR measurement opportunities 810 can be received from a base station or another UE. In some implementations, UE 104 can configure the CBR measurement opportunities 810 to meet minimum monitoring requirements. For example, UE 104 can determine the configuration of the CBR measurement opportunities 810, which guarantees the measurement of at least a minimum number of time slots within a time window 820 of a given length (e.g., 100 ms / time slot). This minimum number can be expressed as a percentage (e.g., X%). For example, for any time slot n, UE 104 can be configured to measure at least X time slots between [n-100, n-1]. Therefore, when UE 104 determines to perform transmission 830, UE 104 can satisfy the CBR measurement requirements. In one respect, UE 104 can independently select time slots that meet the X% requirement based on the configuration of CBR measurement timing 810. Because each UE independently (e.g., randomly) selects CBR measurement timing 810, the probability that UE 104 can measure the activity of another UE can be maximized. Therefore, measurement-based CBR calculation can be more accurate than pre-configured CBR measurement timing. In contrast, if all UEs use the same CBR measurement timing, then all UEs can effectively “receive” during these time slots, and no UE is transmitting. Therefore, one or more UEs may incorrectly determine that the medium is idle or uncongested.

[0079] In one respect, the CBR measurement timing 810 can be periodic (e.g., every Y timeslots). If the periodic measurement corresponds to a periodic transmission, then the periodic CBR measurement timing can provide an accurate measurement of the congestion that may be experienced during the periodic transmission. In another respect, the CBR measurement timing 810 can follow a pseudo-random pattern. The pseudo-random selection of the CBR measurement timing 810 can avoid measuring or missing periodic transmissions. In this way, the pseudo-random selection of the CBR measurement timing 810 can provide a more accurate CBR for any transmission.

[0080] As shown in the figure, some CBR measurement opportunities 810 may occur outside the DRX on duration 422 (i.e., during the DRX off duration 424). For these CBR measurement opportunities 810, UE 104 can wake up to measure RSSI. In one respect, RSSI measurement can consume less power compared to the full receive and decode process used to monitor the control channel.

[0081] Compared to traditional CBR measurements, CBR measurement timing 810 can be spread over a longer time period. More recent CBR measurements can more accurately reflect congestion during transmission. In one aspect, instead of determining the average CBR measurement over window 820, the CBR value can be determined by filtering multiple CBR measurements based on filter coefficients applied to previous CBR values. For example, in some implementations, the filter can be represented by the following formula:

[0082] CBR (n)=α*CBR(n-1) + (1-α)*CBR ins (n-1) (1)

[0083] Where CBR(n) is the CBR value at time slot n, CBR_ins(n-1) is the instantaneous CBR measured at time slot n-1, and α is a filter coefficient with a value between 0 and 1. If the UE performs channel measurements during time slot n-1, CBR_ins(n-1) is given by the ratio of sub-channels in time slot n-1 whose SL-RSSI is greater than a configured threshold. Otherwise, if the UE does not perform channel measurements during time slot n-1, then CBR_ins(n-1) equals CBR(n-1). Therefore, when no measurement is performed in time slot n-1, CBR(n) equals CBR(n-1). Using a filter to determine the CBR of a time slot allows UE 104 to increase the number of measurements used in CBR calculation compared to the average over a fixed time window. If the window remains fixed (e.g., 100 time slots), but UE 104 only measures X% of the time slots, then CBR can be determined based on measurements of only X time slots. In contrast, the filter-based approach allows UE 104 to use more measurement information and also highlights recent measurements.

[0084] Figure 9Figure 900 illustrates an example of CBR measurement with frequency domain resource switching. For example, UE 104 can be configured to have a first frequency domain resource 910 (e.g., BWP 1 or resource pool 1) and a second frequency domain resource 912 (e.g., BWP 2 or resource pool 2). The second bandwidth resource 912 can be greater than the first frequency domain resource 910. In some implementations, the first frequency domain resource 910 can be a subset of the second frequency domain resource 912. UE 104 can be configured to have a CBR measurement timing 920 outside of the active frequency domain resource for UE to measure CBR. For example, when the first frequency domain resource 910 is active, UE 104 can measure the RSSI on the second frequency domain resource 912 during the CBR measurement timing 920 in time window 922. That is, UE 104 can receive a signal on the second frequency domain resource 912 and determine the RSSI. When UE 104 has a large amount of data to transmit or when UE 104 receives a handover signal from another UE, UE 104 can switch to the second frequency domain resource 912. UE 104 can transmit 932 on the second frequency domain resource 912 after the handover time 930. When the second frequency domain resource 912 is active, UE 104 can also measure the RSSI on the second frequency domain resource 912. In one aspect, due to the simplicity of RSSI measurement, the handover time for measuring RSSI during CBR measurement timing 920 can be less than the handover time 930. The handover time for measuring RSSI during CBR measurement timing 920 can be planned based on the configuration of CBR measurement timing 920 and can occur when the first frequency domain resource 910 is active.

[0085] Similar to the DRX scenario, the CBR measurement timing 920 can be configured by the base station (e.g., gNB), another UE (e.g., a host device or repeater), or UE 104 itself. The CBR measurement timing 920 can be configured to meet minimum monitoring requirements. For example, UE 104 can determine the configuration of the CBR measurement timing 920, which guarantees the measurement of at least a minimum number of time slots within a time window 820 of a given length (e.g., 100 ms / slot). For example, for any time slot n, UE 104 can be configured to measure at least X time slots between [n-100, n-1]. Therefore, when UE 104 determines that transmission 932 is performed on the second frequency domain resource 912, UE 104 can meet the CBR measurement requirements.

[0086] In one respect, the CBR measurement timing 920 can be periodic (e.g., every Y timeslots). If the periodic measurement corresponds to a periodic transmission, then the periodic CBR measurement timing can provide an accurate measurement of the congestion that may be experienced during the periodic transmission. In another respect, the CBR measurement timing 920 can follow a pseudo-random pattern. The pseudo-random selection of the CBR measurement timing 920 can avoid measuring or missing periodic transmissions. In this way, the pseudo-random selection of the CBR measurement timing 920 can provide a more accurate CBR for any transmission.

[0087] The filter-based CBR value calculation described above can also be used for CBR measurement timing 920. Similar to CBR measurement timing 810, CBR measurement timing 920 can be spread over a longer time period compared to a fixed window. Using a filter to determine the CBR of a time slot allows UE 104 to increase the number of measurements used in the CBR calculation compared to the average over a fixed time window. If the window remains fixed (e.g., 100 time slots), but UE 104 only measures X% of the time slots during CBR measurement timing 920, the CBR can be determined based on measurements of only X time slots. In contrast, the filter-based method allows UE 104 to use more measurement information and also emphasizes more recent measurements.

[0088] Figure 10 This diagram illustrates resource handover based on CBR measurements. In one aspect, UE 104 can be configured with multiple frequency domain resources (e.g., first frequency domain resource 1010, second frequency domain resource 1012, and third frequency domain resource 1014). UE 104 can be configured with CBR measurement timing for each inactive frequency domain resource, as described above regarding... Figure 9 As discussed, UE 104 can select a new frequency domain resource to activate based on the CBR measurement of an inactive frequency domain resource. For example, if the measured CBR value of the new frequency domain resource is less than a threshold, UE 104 can select the new frequency domain resource to activate. Conversely, if the measured CBR value of the active frequency domain resource is greater than a second threshold, UE 104 can not activate the active frequency domain resource. In one aspect, UE 104 can send an activation signal 1020 or an activation / deactivation signal 1022 when switching frequency domain resources. The activation signal 1020 or the activation / deactivation signal 1022 can notify another UE which frequency domain resource is used for subsequent transmissions.

[0089] UE 104 can maintain at least one active frequency domain resource. For example, UE 104 can be configured to maintain an active primary frequency domain resource (e.g., first frequency domain resource 1010) while dynamically activating or deactivating other frequency domain resources (e.g., second frequency domain resource 1012 and third frequency domain resource 1014). In another implementation, UE 104 can switch from an active frequency domain resource (e.g., second frequency domain resource 1012) to an inactive frequency domain resource (e.g., third frequency domain resource 1014) by deactivating the active frequency domain resource and activating the inactive frequency domain resource during handover time 1030.

[0090] Figure 11 Figure 1100 illustrates example communication and components of base station 102, first UE 104-a, and second UE 104-b. UEs 104-a and 104-b may each include a lateral link CBR component 140. The first UE 104-a may be a lateral link transmitting UE, and the second UE 104-b may be a lateral link receiving UE. (See above regarding...) Figure 1 The first UE 104-a discussed may include a configuration component 142, a measurement component 144, a congestion controller 146, and a transmission component 148. UE 104 may also include a receiver component 1110 and a transmitter component 1112. Receiver component 1110 may include, for example, an RF receiver for receiving the signals described herein. Transmitter component 1112 may include, for example, an RF transmitter for transmitting the signals described herein. In one aspect, receiver component 1110 and transmitter component 1112 may be implemented as transceivers.

[0091] Base station 102 may include a lateral link configuration component 198. Base station 102 may send SL configuration 1120 to first UE 104-a and lateral link configuration 1122 to second UE 104-b. For example, lateral link configurations 1120 and 1122 may be radio resource control (RRC) messages, media access control (MAC) control elements (CE), or downlink control information (DCI) carried on the PDCCH. Configuration component 142 at each of the first UE 104-a and the second UE 104-b may receive the corresponding lateral link configurations 1120 and 1122.

[0092] First UE 104-a and second UE 104-b can communicate via communication link 158, which may be referred to as a direct link or a side link. In one aspect, first UE 104-a can monitor communication link 158 by performing CBR measurement 1132 to determine a CBR value. First UE 104-a can optionally send a handover signal 1134 indicating a change in frequency domain resources, or receive a handover signal 1134 indicating that second UE 104-b has changed frequency domain resources. First UE 104-a can perform congestion control 1136 by limiting the CR (channel occupancy rate) of transmission 1138 to less than a configured threshold based on the measured CBR value. In one aspect, SL configuration 1120 may include power-saving configurations such as DRX configuration, WUS configuration, or frequency domain resource configuration including multiple frequency domain resources (e.g., bandwidth portions or resource pools).

[0093] The configuration component 142 of the first UE 104-a can identify configurations for direct link communication. For example, the first UE 104-a may receive SL configuration 1120 from base station 102. In another aspect, the first UE 104-a may identify configurations based on standard documents or rules (e.g., default configurations). In yet another aspect, the first UE 104-a may receive lateral link configurations from another UE (e.g., UE 104-b), which may forward lateral link configurations from the base station. In one aspect, the configuration component 142 can identify DRX configurations (e.g., DRX configuration 1140) for direct link communication with the second UE 104-b. For example, DRX configuration 1140 may define a DRX period 420, a DRX on duration 422, and / or a DRX off duration 424. DRX configuration 1140 may also include a WUS monitoring period 430. In one aspect, the configuration component 142 can identify frequency domain resource configuration 1142. Frequency domain resource configuration 1142 may include configurations of first and second frequency domain resources for direct link communication with the second UE 104-b. For example, this configuration may define first frequency domain resources 510, 610, 910, or 1010 and second frequency domain resources 512, 612, 912, or 1012. Frequency domain resource configuration 1142 may also define a third frequency domain resource 1014. Frequency domain resource configuration 1142 may indicate whether each configured frequency domain resource is active or inactive.

[0094] Configuration component 142 can also identify CBR timing configuration 1130. For example, CBR timing configuration 1130 can be received within SL configuration 1120 or in other signaling from base station 102. As another example, configuration component 142 can receive CBR timing configuration 1130 from another UE, such as a second UE 104-b. As yet another example, UE 104-a and / or configuration component 142 can determine CBR timing configuration 1130 according to rules defined in standard documents or regulations. In one aspect, some parameters of this rule (e.g., the value of X) can be signaled by base station 102 and / or the second UE 104-b. CBR timing configuration 1130 can define CBR measurement timing 810 or 920.

[0095] Measurement component 144 can perform CBR measurement 1132 based on CBR timing configuration 1130. Specifically, measurement component 144 can measure RSSI during CBR measurement timing 810 or 920. Measurement component 144 can perform CBR measurement on time-domain and / or frequency-domain resources where UE 104-a is not configured to receive transmissions. For example, measurement component 144 can perform CBR measurement at CBR measurement timing 810 during DRX off duration 424, or at CBR measurement timing 920 on inactive frequency-domain resources.

[0096] Congestion controller 146 can determine whether to perform congestion control on direct link transmission 1138 based on the Congestion Response Rate (CBR). For example, congestion controller 146 can determine CR limit 1160 based on the CBR. Congestion controller 146 can limit parameters of transmission 1138 to ensure that the CR of transmission 1138 is less than CR limit 1160. For example, CR limit 1160 can be defined as a portion of subchannels used for transmission in [na, n-1] and licensed / reserved in [n, n+b], where a is a positive integer, b is a non-negative integer; a+b+1 = 1000; and a >= 500. The value n+b should not exceed the last transmission opportunity licensed for transmission 1138. For example, congestion controller 146 can limit one or more of the modulation and coding scheme (MCS) table or index, the number of subchannels, the number of retransmissions, or the transmission power to satisfy CR limit 1160.

[0097] Transmission component 148 can transmit transmission 1138 based on congestion control determined by congestion controller 146. For example, transmission component 148 can select MCS, number of sub-channels, number of retransmissions, and transmission power based on congestion control. Transmission component 148 can transmit transmission 1138 via transmitter component 1112.

[0098] Figure 12This is a conceptual data flow diagram 1200 illustrating the data flow between different units / components in an exemplary UE 1204, which may be an example of a UE 104 including a lateral link CBR component 140.

[0099] Receiver component 1110 can receive downlink signals such as SL configuration 1120 and / or CBR timing configuration 1130. Receiver component 1110 can transmit configuration messages to configuration component 142. Receiver component 1110 can receive lateral link signals such as PSCCH, PSSCH, and PSFCH, which may be directed to UE 1204 or another UE. Receiver component 1110 can transmit lateral link signals to measurement component 144.

[0100] Configuration component 142 can receive SL configuration 1120 and / or CBR timing configuration 1130 from receiver component 1110. Configuration component 142 can decode the received configuration and provide configuration information (e.g., CBR measurement timing) to measurement component 144.

[0101] Measurement component 144 can receive CBR measurement timing from configuration component 142. Measurement component 144 can receive lateral link signals from receiver component 1110. Measurement component 144 can perform RSSI measurements on lateral link signals during CBR measurement timing. Measurement component 144 can further determine CBR values ​​based on RSSI measurements. For example, measurement component 144 can determine the average number of sub-channels occupied during measurement window 710. As another example, measurement component 144 can determine a weighted CBR by filtering multiple CBR measurements based on filter coefficients (α) applied to previous CBR values.

[0102] Congestion controller 146 can receive CBR values ​​from measurement component 144 and determine CR limit 1160. CR limit 1160 can limit one or more of the following values: MCS table or index, number of sub-channels, number of retransmissions, or transmission power. Congestion controller 146 can provide CR limit 1160 to transmission component 148.

[0103] Transmission component 148 can determine transmission parameters based on CR limit 1160, data volume, and channel conditions. For example, transmission component 148 can select the MCS, number of sub-channels, number of retransmissions, and transmission power to satisfy CR limit 1160. Transmission component 148 can provide lateral link signals and transmission parameters to transmitter component 1112 for transmission.

[0104] Figure 13This is a flowchart of an example method 1300 for operating UE 104 (e.g., first UE 104-a) to perform lateral link transmissions according to a DRX configuration with congestion control. Method 1300 can be performed by a UE (e.g., UE 104, which may include memory 360 and may be the entire UE 104, or a component of UE 104 such as lateral link CBR component 140, TX processor 368, RX processor 356, or controller / processor 359). Method 1300 can be performed by a lateral link CBR component 140 communicating with a lateral link configuration component 198 of base station 102 and a lateral link CBR component 140 of another UE 104.

[0105] At block 1310, method 1300 may include identifying a DRX configuration for lateral link communication. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may execute lateral link CBR component 140, receiver component 1110, and / or configuration component 142 to identify a DRX configuration (e.g., DRX configuration 1140) for lateral link communication. For example, lateral link communication may include direct communication with at least a second UE 104-b. Lateral link communication may include multicast communication with a group of UEs, or broadcast communication where one or more receiving UEs are unknown. In one aspect, receiver component 1110 and / or configuration component 142 may receive DRX configuration 1140 from base station 102 (e.g., within SL configuration 1120). In another aspect, DRX configuration 1140 may be a default configuration defined by a standard document or rule. Therefore, the UE 104, RX processor 356, and / or controller / processor 359 that execute the lateral link CBR component 140, receiver component 1110, and / or configuration component 142 can provide a unit for identifying the configuration for DRX on lateral link communication.

[0106] At block 1320, method 1300 may include determining multiple CBR measurement timings based on the configuration for DRX. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may execute lateral link CBR component 140 and / or configuration component 142 to determine multiple CBR measurement timings 810 based on the configuration for DRX. For example, at sub-block 1322, configuration component 142 may determine multiple CBR measurement timings occurring during the on-duration of the configuration for DRX. That is, configuration component 142 may select a CBR measurement timing 810 occurring during the DRX on-duration duration 422. Furthermore, when UE 104 is configured with WUS, configuration component 142 may select a CBR measurement timing 810 occurring upon UE 104 wake-up. As another example, at sub-block 1324, configuration component 142 may determine at least one CBR measurement timing outside the on-duration of the configuration for DRX. For example, configuration component 142 may select at least one CBR measurement timing 810 during the DRX off duration 424. Therefore, UE 104, RX processor 356, and / or controller / processor 359, which perform lateral link CBR component 140 and / or configuration component 142, may provide units for determining multiple CBR measurement timings based on the configuration for DRX.

[0107] At block 1330, method 1300 may include determining the CBR based on measurements of the plurality of CBR measurement moments. In one aspect, for example, UE 104, RX processor 356, and / or controller / processor 359 may execute lateral link CBR component 140 and / or measurement component 144 to determine the CBR based on measurements of the plurality of CBR measurement moments 810 (e.g., CBR measurement 1132). For example, measurement component 144 may measure the plurality of CBR measurement moments 810 within a time window 820 prior to lateral link transmission 830 based on a configuration for DRX. For example, measurement component 144 may measure the received signal during each CBR measurement moment 810 to determine the RSSI for each CBR moment. In one aspect, the plurality of CBR measurement moments are periodic. In another aspect, the plurality of CBR measurement moments are pseudo-random. The first UE may configure the plurality of CBR measurement moments to include at least a minimum number of time slots within a time window (e.g., time window 710 or 820). In one aspect, UE 104 can be configured to have lateral link carrier aggregation for multiple component carriers. The CBR measurement timing 712 or 810 can be configured individually for each of the multiple component carriers. Alternatively, the CBR measurement timing can be configured jointly for the multiple component carriers.

[0108] In one aspect, within sub-block 1332, block 1330 may include: waking up during at least one CBR measurement opportunity outside the on-duration of the DRX configuration to measure RSSI. For example, sub-block 1332 may be performed in response to sub-block 1324. For example, measurement component 144 may wake up receiver component 1110 to measure the lateral link signal at CBR measurement opportunity 810 occurring during the DRX off-duration duration 424. In one aspect, within sub-block 1334, block 1330 may include: filtering multiple CBR measurements based on filter coefficients (α) applied to previous CBR values. For example, measurement component 144 may filter multiple CBR measurements according to equation (1) above. In another aspect, if UE 104 is configured with lateral link carrier aggregation, at sub-block 1336, block 1330 may include: determining CBR based solely on the active component carriers. Alternatively, in sub-block 1338, block 1330 may include: measuring RSSI on one or more inactive component carriers among the plurality of component carriers during the plurality of CBR measurement opportunities 810. In view of the foregoing, the UE 104, RX processor 356, TX processor 368, and / or controller / processor 359 performing the lateral link CBR component 140 and / or measurement component 144 may provide units for determining the CBR based on measurements at the plurality of CBR measurement opportunities.

[0109] At block 1340, method 1300 may optionally include: determining whether to perform congestion control on lateral link transmissions based on CBR. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may execute lateral link CBR component 140 and / or congestion controller 146 to determine whether to perform congestion control on lateral link transmissions 1138 based on CBR 1150. Therefore, UE 104, TX processor 368, and / or controller / processor 359 executing lateral link CBR component 140 and / or congestion controller 146 may provide units for determining whether to perform congestion control on lateral link transmissions based on CBR.

[0110] At block 1350, method 1300 may optionally include performing a lateral link transmission subject to channel occupancy restrictions. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may perform a lateral link CBR component 140 and / or transmission component 148 to perform a lateral link transmission 1138 subject to channel occupancy restrictions (e.g., CR restriction 1160). CR restriction 1160 can provide congestion control by limiting the resources used by the first UE 104-a. Therefore, UE 104, TX processor 368, and / or controller / processor 359 performing the lateral link CBR component 140 and / or transmission component 148 may provide elements for performing a lateral link transmission subject to channel occupancy restrictions.

[0111] Figure 14 This is a flowchart of an example method 1400 for operating UE 104 (e.g., first UE 104-a) to perform lateral link transmission with congestion control based on a frequency domain configuration having multiple frequency domain resources. Method 1400 can be performed by a UE (e.g., UE 104, which may include memory 360 and may be the entire UE 104, or a component of UE 104 such as lateral link CBR component 140, TX processor 368, RX processor 356, or controller / processor 359). Method 1300 can be performed by a lateral link CBR component 140 communicating with a lateral link configuration component 198 of base station 102 and a lateral link CBR component 140 of another UE 104.

[0112] At block 1410, method 1400 may include: identifying a configuration of frequency domain resources for lateral link communication, the configuration including a first frequency domain resource and a second frequency domain resource. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may execute lateral link CBR component 140 and / or configuration component 142 to identify a configuration of frequency domain resources for lateral link communication (e.g., frequency domain resource configuration 1142). For example, lateral link communication may include unicast, multicast, or broadcast communication with at least a second UE 104-b. Frequency domain resource configuration 1142 may include a first frequency domain resource 910 or 1010 and a second frequency domain resource 912 or 1012. For example, configuration component 142 may receive frequency domain resource configuration 1142 from base station 102 (e.g., within SL configuration 1120). Therefore, the UE 104, RX processor 356, and / or controller / processor 359 that execute the lateral link CBR component 140 and / or configuration component 142 can provide a unit for configuring frequency domain resources for identifying lateral link communication with the second UE.

[0113] At block 1420, method 1400 may include measuring the RSSI on the second frequency domain resource during a plurality of CBR measurement opportunities within a time window preceding a lateral link transmission on the second frequency domain resource when the second frequency domain resource is inactive. In one aspect, for example, UE 104, RX processor 356, and / or controller / processor 359 may execute lateral link CBR component 140 and / or measurement component 144 to measure the RSSI 1152 on the second frequency domain resource 912 or 1012 during a plurality of CBR measurement opportunities 920 within a time window 922 preceding a lateral link transmission 932 on the second frequency domain resource 912 when the second frequency domain resource is inactive. For example, measurement component 144 may measure the received signal during each CBR measurement opportunity to determine the RSSI 1152 for each CBR opportunity. In one aspect, the plurality of CBR measurement opportunities are periodic. In another aspect, the plurality of CBR measurement opportunities are pseudo-random. The first UE can configure the plurality of CBR measurement timings to include at least a minimum number of time slots within a time window (e.g., time window 922). In one aspect, UE 104 can be configured to have direct link carrier aggregation for multiple component carriers. CBR measurement timings 712 or 810 can be configured individually for each of the multiple component carriers. Alternatively, CBR measurement timings can be configured jointly for the multiple component carriers.

[0114] In view of the above, the UE 104, RX processor 356, TX processor 368, and / or controller / processor 359 that perform the lateral link CBR component 140 and / or measurement component 144 may provide a unit for measuring the Received Signal Strength Indicator (RSSI) on the second frequency domain resource during multiple CBR measurement opportunities within a time window prior to direct link transmission on the second frequency domain resource when the second frequency domain resource is inactive.

[0115] At block 1430, method 1400 may include: determining the CBR of a second frequency domain resource based on the RSSI of the plurality of CBR measurement timings. In one aspect, for example, UE 104, RX processor 356, and / or controller / processor 359 may execute lateral link CBR component 140 and / or measurement component 144 to determine the CBR 1150 of the second frequency domain resource based on the RSSI 1152 of the plurality of CBR measurement timings. In one aspect, at sub-block 1432, block 1430 may include: filtering the plurality of CBR measurements based on filter coefficients (α) applied to previous CBR values. For example, measurement component 144 may filter the plurality of CBR measurements according to equation (1) above. In one aspect, if UE 104 is configured with lateral link carrier aggregation, at sub-block 1434, block 1430 may include: determining the CBR based only on the active component carriers. Alternatively, in sub-block 1436, block 1430 may include: measuring RSSI on one or more inactive component carriers among the plurality of component carriers during the plurality of CBR measurement opportunities. In view of the above, UE 104, RX processor 356, Tx processor 368, and / or controller / processor 359 performing the lateral link CBR component 140 and / or measurement component 144 may provide a unit for measuring RSSI on the second frequency domain resource during the plurality of CBR measurement opportunities within a time window prior to direct link transmission on the second frequency domain resource when the second frequency domain resource is inactive.

[0116] At block 1440, method 1400 may optionally include activating a second frequency domain resource in response to a CBR meeting a threshold. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may execute lateral link CBR component 140 and / or congestion controller 146 to activate second frequency domain resources 912, 1012 in response to a CBR meeting a threshold. For example, congestion controller 146 may determine to activate second frequency domain resources 912, 1012 in response to a measured CBR 1150 being less than a first threshold. The first threshold may be configured via frequency domain resource configuration 1142. Therefore, UE 104, TX processor 368, and / or controller / processor 359 executing lateral link CBR component 140 and / or congestion controller 146 may provide elements for activating the second frequency domain resource in response to a CBR meeting a threshold.

[0117] At block 1450, method 1400 may optionally include: not activating a second frequency domain resource in response to CBR being greater than a second threshold. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may execute lateral link CBR component 140 and / or congestion controller 146 to not activate second frequency domain resources 912, 1012 in response to CBR 1150 being greater than a second threshold. The second threshold may be configured via frequency domain resource configuration 1142. In one aspect, when second frequency domain resource 1012 is not activated, congestion controller 146 may switch from second frequency domain source 1012 to third frequency domain resource 1014. Therefore, UE 104, TX processor 368, and / or controller / processor 359 executing lateral link CBR component 140 and / or congestion controller 146 may provide elements for activating the second frequency domain resource in response to CBR meeting the threshold.

[0118] At block 1460, method 1400 may optionally include determining whether to perform congestion control on direct link transmission based on CBR. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may execute lateral link CBR component 140 and / or congestion controller 146 to determine whether to perform congestion control on direct link transmission 1138 based on CBR 1150. Therefore, UE 104, TX processor 368, and / or controller / processor 359 executing lateral link CBR component 140 and / or congestion controller 146 may provide units for determining whether to perform congestion control on direct link transmission based on CBR.

[0119] At block 1470, method 1400 may optionally include performing a direct link transmission subject to channel occupancy limitations. In one aspect, for example, UE 104, TX processor 368, and / or controller / processor 359 may perform a side-link CBR component 140 and / or transmission component 148 to perform a direct link transmission 1138 subject to channel occupancy limitations (e.g., CR limitation 1160). Therefore, UE 104, TX processor 368, and / or controller / processor 359 performing the side-link CBR component 140 and / or transmission component 148 may provide elements for performing a direct link transmission subject to channel occupancy limitations.

[0120] Some further example terms

[0121] Implementation examples are described in the following numbered clauses:

[0122] 1. A method for wireless communication, comprising at a first user equipment (UE):

[0123] Identify the configuration used for discontinuous reception (DRX) on lateral link communication;

[0124] Based on the configuration used for DRX, determine the timing of multiple Channel Busy Ratio (CBR) measurements; and

[0125] The CBR is determined based on measurements taken at the aforementioned multiple CBR measurement times.

[0126] 2. The method according to Clause 1, wherein determining the plurality of CBR measurement timings comprises: determining the plurality of CBR measurement timings that occur during the on-duration period of the configuration for DRX.

[0127] 3. The method according to Clause 1, wherein determining the plurality of CBR measurement timings comprises: determining at least one CBR measurement timing outside the on-duration of the configuration for DRX, and wherein determining the CBR based on the measurement of the plurality of CBR measurement timings comprises: waking up during the at least one CBR measurement timing outside the on-duration of the configuration for DRX to measure the Received Signal Strength Indicator (RSSI).

[0128] 4. The method according to any one of clauses 1-3, wherein the plurality of CBR measurements are performed periodically.

[0129] 5. The method according to any one of clauses 1-3, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0130] 6. The method according to any one of clauses 1-5, wherein determining the CBR comprises: filtering a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0131] 7. The method according to any one of clauses 1-6, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement timings are configured individually for each of the plurality of component carriers.

[0132] 8. The method according to any one of clauses 1-6, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and the multiple CBR measurement timings are jointly configured for the multiple component carriers.

[0133] 9. The method according to any one of clauses 1-8, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein determining the CBR comprises: determining the CBR based solely on the active component carriers.

[0134] 10. The method according to any one of clauses 1-8, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein determining the CBR comprises: measuring RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement timings.

[0135] 11. The method according to any one of clauses 1-10, wherein the plurality of CBR measurement timings are configured by the first UE to include at least a minimum number of time slots within a time window prior to lateral link transmission.

[0136] 12. The method according to any one of clauses 1-11 further comprises: determining, based on the CBR, whether to perform congestion control on lateral link transmissions.

[0137] 13. An apparatus for wireless communication for a first user equipment (UE), comprising:

[0138] Memory, which stores computer-executable instructions; and

[0139] At least one processor coupled to the memory, configured to execute the computer-executable instructions for:

[0140] Identify the configuration used for discontinuous reception (DRX) on lateral link communication;

[0141] Based on the configuration used for DRX, determine the timing of multiple Channel Busy Ratio (CBR) measurements; and

[0142] The CBR is determined based on measurements taken at the aforementioned multiple CBR measurement times.

[0143] 14. The apparatus according to Clause 13, wherein the at least one processor is configured to: determine the timing of the plurality of CBR measurements occurring during the on-duration of the configuration for DRX.

[0144] 15. The apparatus according to Clause 13, wherein the at least one processor is configured to:

[0145] Determine at least one CBR measurement opportunity outside the on-time of the configuration used for DRX; and

[0146] Wake up during at least one CBR measurement opportunity outside of the on-time of the configuration used for DRX to measure the Received Signal Strength Indicator (RSSI).

[0147] 16. The apparatus according to any one of clauses 13-15, wherein the plurality of CBR measurements are performed periodically.

[0148] 17. The apparatus according to any one of clauses 13-15, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0149] 18. The apparatus according to any one of clauses 13-17, wherein the at least one processor is configured to filter a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0150] 19. The apparatus according to any one of clauses 13-18, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement timings are configured individually for each of the plurality of component carriers.

[0151] 20. The apparatus according to any one of clauses 13-18, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement timings are jointly configured for the plurality of component carriers.

[0152] 21. The apparatus according to any one of clauses 13-20, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein the at least one processor is configured to determine the CBR based solely on the active component carriers.

[0153] 22. The apparatus according to any one of clauses 13-20, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein the at least one processor is configured to: determine, during the plurality of CBR measurement times, measure RSSI on one or more inactive component carriers among the plurality of component carriers.

[0154] 23. The apparatus according to any one of clauses 13-22, wherein the plurality of CBR measurement timings are configured by the first UE to include at least a minimum number of time slots within a time window prior to lateral link transmission.

[0155] 24. The apparatus according to any one of clauses 13-23, wherein the at least one processor is configured to determine, based on the CBR, whether to perform congestion control on lateral link transmissions.

[0156] 25. An apparatus for wireless communication for a first user equipment (UE):

[0157] A unit used to identify the configuration for discontinuous reception (DRX) on lateral link communication;

[0158] A unit for determining the timing of multiple Channel Busy Ratio (CBR) measurements based on the configuration used for DRX; and

[0159] A unit used to determine the CBR based on measurements taken at the multiple CBR measurement times.

[0160] 26. The apparatus according to Clause 25, wherein the unit for determining the plurality of CBR measurement timings is configured to: determine the plurality of CBR measurement timings occurring during the on-time of the configuration for DRX.

[0161] 27. The apparatus according to Clause 25, wherein the unit for determining the plurality of CBR measurement timings is configured to: determine at least one CBR measurement timing outside the on-duration of the configuration for DRX, and wherein the unit for determining the CBR based on measurements of the plurality of CBR measurement timings is configured to: wake up during the at least one CBR measurement timing outside the on-duration of the configuration for DRX to measure the Received Signal Strength Indicator (RSSI).

[0162] 28. The apparatus according to any one of clauses 25-27, wherein the plurality of CBR measurements are performed periodically.

[0163] 29. The apparatus according to any one of clauses 25-27, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0164] 30. The apparatus according to any one of clauses 25-29, wherein the unit for determining the CBR is configured to filter a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0165] 31. The apparatus according to any one of clauses 25-30, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement timings are configured individually for each of the plurality of component carriers.

[0166] 32. The apparatus according to any one of clauses 25-30, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement timings are jointly configured for the plurality of component carriers.

[0167] 33. The apparatus according to any one of clauses 25-32, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein the unit for determining the CBR is configured to determine the CBR based solely on the active component carriers.

[0168] 34. The apparatus according to any one of clauses 25-32, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein the unit for determining the CBR is configured to: measure RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement timings.

[0169] 35. The apparatus according to any one of clauses 25-34, wherein the plurality of CBR measurement timings are configured by the first UE to include at least a minimum number of time slots within a time window prior to lateral link transmission.

[0170] 36. The apparatus according to any one of clauses 25-35 further includes: a unit for determining, based on the CBR, whether to perform congestion control on lateral link transmissions.

[0171] 37. A non-transitory computer-readable medium storing computer-executable code, which, when executed by at least one processor, causes the at least one processor to perform the following operations at a first user equipment (UE):

[0172] Identify the configuration used for discontinuous reception (DRX) on lateral link communication;

[0173] Based on the configuration used for DRX, determine the timing of multiple Channel Busy Ratio (CBR) measurements; and

[0174] The CBR is determined based on measurements taken at the aforementioned multiple CBR measurement times.

[0175] 38. The non-transitory computer-readable medium according to Clause 37, wherein the code for determining the plurality of CBR measurement timings includes: code for determining the plurality of CBR measurement timings occurring during the on-time duration of the configuration for DRX.

[0176] 39. The non-transitory computer-readable medium according to Clause 37, wherein the code for determining the plurality of CBR measurement timings comprises: code for determining at least one CBR measurement timing outside the on-duration of the configuration for DRX, and wherein determining the CBR based on the measurement of the plurality of CBR measurement timings comprises: waking up during the at least one CBR measurement timing outside the on-duration of the configuration for DRX to measure the Received Signal Strength Indicator (RSSI).

[0177] 40. The non-transitory computer-readable medium according to any one of clauses 37-39, wherein the plurality of CBR measurements are performed periodically.

[0178] 41. The non-transitory computer-readable medium according to any one of clauses 37-39, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0179] 42. The non-transitory computer-readable medium according to any one of clauses 37-41, wherein the code for determining the CBR includes: code for filtering a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0180] 43. A non-transitory computer-readable medium according to any one of clauses 37-42, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement timings are configured individually for each of the plurality of component carriers.

[0181] 44. A non-transitory computer-readable medium according to any one of clauses 37-42, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement timings are jointly configured for the plurality of component carriers.

[0182] 45. A non-transitory computer-readable medium according to any one of clauses 37-44, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein the code for determining the CBR includes: code for determining the CBR based solely on the active component carriers.

[0183] 46. ​​A non-transitory computer-readable medium according to any one of clauses 37-44, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein the code for determining the CBR includes: code for measuring RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement timings.

[0184] 47. A non-transitory computer-readable medium according to any one of clauses 37-46, wherein the plurality of CBR measurement timings are configured by the first UE to include at least a minimum number of time slots within a time window prior to lateral link transmission.

[0185] 48. The non-transitory computer-readable medium according to any one of clauses 37-47 further includes: code for determining, based on the CBR, whether to perform congestion control on lateral link transmissions.

[0186] 49. A method of wireless communication, comprising at a first user equipment (UE):

[0187] Identify the configuration of frequency domain resources used for lateral link communication, the configuration including a first frequency domain resource and a second frequency domain resource;

[0188] When the second frequency domain resource is inactive, the Received Signal Strength Indicator (RSSI) on the second frequency domain resource is measured during multiple Channel Busy Ratio (CBR) timings within a time window preceding lateral link transmission on the second frequency domain resource; and

[0189] The CBR of the second frequency domain resource is determined based on the RSSI at the time of the plurality of CBR measurements.

[0190] 50. The method according to Clause 49 further includes: determining to activate the second frequency domain resource in response to the CBR satisfying a first threshold.

[0191] 51. The method according to Clause 50 further includes: determining, in response to the CBR being greater than a second threshold, not activating the second frequency domain resource.

[0192] 52. The method according to any one of clauses 49-51, wherein the plurality of CBR measurements are performed periodically.

[0193] 53. The method according to any one of clauses 49-51, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0194] 54. The method according to any one of clauses 49-53, wherein determining the CBR comprises: filtering a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0195] 55. The method according to any one of clauses 49-54, wherein the first UE configures the plurality of CBR measurement timings to include at least a minimum number of time slots within the time window.

[0196] 56. The method according to any one of clauses 49-55 further comprises: determining, based on the CBR, whether to perform congestion control on the lateral link transmission.

[0197] 57. The method according to any one of clauses 49-56, wherein the first frequency domain resource is a first component carrier, a first bandwidth portion, or a first resource pool, and the second frequency domain resource is a second component carrier, a second bandwidth portion, or a second resource pool.

[0198] 58. The method according to any one of clauses 49-57, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein determining the CBR comprises: determining the CBR based solely on the active component carriers.

[0199] 59. The method according to any one of clauses 49-57, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein determining the CBR comprises: measuring the RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement timings.

[0200] 60. An apparatus for wireless communication for a first user equipment (UE), comprising:

[0201] Memory, which stores computer-executable instructions; and

[0202] At least one processor coupled to the memory, configured to execute the computer-executable instructions for:

[0203] Identify the configuration of frequency domain resources used for lateral link communication, the configuration including a first frequency domain resource and a second frequency domain resource;

[0204] When the second frequency domain resource is inactive, the Received Signal Strength Indicator (RSSI) on the second frequency domain resource is measured during multiple Channel Busy Ratio (CBR) timings within a time window preceding lateral link transmission on the second frequency domain resource; and

[0205] The CBR of the second frequency domain resource is determined based on the RSSI at the time of the plurality of CBR measurements.

[0206] 61. The apparatus according to Clause 60, wherein the at least one processor is configured to activate the second frequency domain resource in response to the CBR satisfying a first threshold.

[0207] 62. The apparatus according to Clause 61, wherein the at least one processor is configured to: in response to the CBR being greater than a second threshold, not activate the second frequency domain resource.

[0208] 63. The apparatus according to any one of clauses 60-62, wherein the plurality of CBR measurements are performed periodically.

[0209] 64. The apparatus according to any one of clauses 60-62, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0210] 65. The apparatus according to any one of clauses 60-64, wherein the at least one processor is configured to filter a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0211] 66. The apparatus according to any one of clauses 60-65, wherein the first UE configures the plurality of CBR measurement timings to include at least a minimum number of time slots within the time window.

[0212] 67. The apparatus according to any one of clauses 60-66, wherein the at least one processor is configured to determine, based on the CBR, whether to perform congestion control on the lateral link transmission.

[0213] 68. The apparatus according to any one of clauses 60-67, wherein the first frequency domain resource is a first component carrier, a first bandwidth portion, or a first resource pool, and the second frequency domain resource is a second component carrier, a second bandwidth portion, or a second resource pool.

[0214] 69. The apparatus according to any one of clauses 60-68, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein the at least one processor is configured to determine the CBR based only on the active component carriers.

[0215] 70. The apparatus according to any one of clauses 60-68, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein the at least one processor is configured to: measure the RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement times.

[0216] 71. An apparatus for wireless communication for a first user equipment (UE):

[0217] A unit for identifying the configuration of frequency domain resources for lateral link communication, the configuration including a first frequency domain resource and a second frequency domain resource;

[0218] A unit for measuring the Received Signal Strength Indicator (RSSI) on the second frequency domain resource during multiple Channel Busy Ratio (CBR) timings within a time window prior to lateral link transmission on the second frequency domain resource when the second frequency domain resource is inactive; and

[0219] A unit for determining the CBR of the second frequency domain resource based on the RSSI at the time of the plurality of CBR measurements.

[0220] 72. The apparatus according to Clause 71 further includes: a unit for activating the second frequency domain resource in response to the CBR satisfying a first threshold.

[0221] 73. The apparatus according to Clause 72, wherein the activation unit is configured to: determine not to activate the second frequency domain resource in response to the CBR being greater than a second threshold.

[0222] 74. The apparatus according to any one of clauses 71-73, wherein the plurality of CBR measurements are performed periodically.

[0223] 75. The apparatus according to any one of clauses 71-73, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0224] 76. The apparatus according to any one of clauses 71-75, wherein the unit for determining the CBR is configured to filter a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0225] 77. The apparatus according to any one of clauses 71-77, wherein the first UE configures the plurality of CBR measurement timings to include at least a minimum number of time slots within the time window.

[0226] 78. The apparatus according to any one of clauses 71-78 further includes: a unit for determining, based on the CBR, whether to perform congestion control on the lateral link transmission.

[0227] 79. The apparatus according to any one of clauses 71-79, wherein the first frequency domain resource is a first component carrier, a first bandwidth portion, or a first resource pool, and the second frequency domain resource is a second component carrier, a second bandwidth portion, or a second resource pool.

[0228] 80. The apparatus according to any one of clauses 71-80, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein the unit for determining the CBR is configured to determine the CBR based solely on the active component carriers.

[0229] 81. The apparatus according to any one of clauses 71-80, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein the unit for determining the CBR is configured to: measure the RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement timings.

[0230] 82. A non-transitory computer-readable medium storing computer-executable code, which, when executed by at least one processor of a first user equipment (UE), causes the at least one processor to perform the following operations:

[0231] Identify the configuration of frequency domain resources used for lateral link communication, the configuration including a first frequency domain resource and a second frequency domain resource;

[0232] When the second frequency domain resource is inactive, the Received Signal Strength Indicator (RSSI) on the second frequency domain resource is measured during multiple Channel Busy Ratio (CBR) timings within a time window preceding lateral link transmission on the second frequency domain resource; and

[0233] The CBR of the second frequency domain resource is determined based on the RSSI at the time of the plurality of CBR measurements.

[0234] 83. The non-transitory computer-readable medium according to Clause 82 further includes: determining activation of the second frequency domain resource in response to the CBR satisfying a first threshold.

[0235] 84. The non-transitory computer-readable medium as described in Clause 83 further includes: determining, in response to the CBR being greater than a second threshold, not to activate the second frequency domain resource.

[0236] 85. The non-transitory computer-readable medium according to any one of clauses 82-84, wherein the plurality of CBR measurements are performed periodically.

[0237] 86. A non-transitory computer-readable medium according to any one of clauses 82-84, wherein the timing of the plurality of CBR measurements is pseudo-random.

[0238] 87. A non-transitory computer-readable medium according to any one of clauses 82-86, wherein determining the CBR comprises: filtering a plurality of CBR measurements based on filter coefficients applied to a previous CBR value.

[0239] 88. A non-transitory computer-readable medium according to any one of clauses 82-87, wherein the first UE configures the plurality of CBR measurement timings to include at least a minimum number of time slots within the time window.

[0240] 89. The non-transitory computer-readable medium according to any one of clauses 82-88 further includes: determining, based on the CBR, whether to perform congestion control on the lateral link transmission.

[0241] 90. A non-transitory computer-readable medium according to any one of clauses 82-89, wherein the first frequency domain resource is a first component carrier, a first bandwidth portion, or a first resource pool, and the second frequency domain resource is a second component carrier, a second bandwidth portion, or a second resource pool.

[0242] 91. A non-transitory computer-readable medium according to any one of clauses 82-90, wherein the first UE is configured to have lateral link carrier aggregation for multiple component carriers, and wherein determining the CBR comprises: determining the CBR based solely on the active component carriers.

[0243] 92. A non-transitory computer-readable medium according to any one of clauses 82-90, wherein the first UE is configured to have lateral link carrier aggregation for a plurality of component carriers, and wherein determining the CBR comprises: measuring the RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement timings.

[0244] It should be understood that the specific order or hierarchy of blocks in the processing / flowcharts disclosed herein is merely an example of an exemplary method. It should be understood that these specific orders or hierarchies of blocks in the processing / flowcharts may be rearranged based on design preferences. Furthermore, some blocks may be combined or omitted. The appended method claims give the elements of various blocks in an exemplary order, but this does not imply that they are limited to the given specific order or hierarchy.

[0245] To enable any person skilled in the art to implement the various aspects described herein, the foregoing descriptions have been made regarding these aspects. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may also be applied to other aspects. Therefore, the invention is not limited to the aspects shown herein, but is consistent with the full scope of the invention disclosure, wherein, unless specifically stated otherwise, the use of the singular to modify a component does not mean "one and only one," but can mean "one or more." The term "exemplary" as used herein means "serving as an example, illustration, or description." Any aspect described herein as "exemplary" should not be construed as preferred or advantageous over other aspects. Unless otherwise specifically stated otherwise, 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," including any combination of A, B, and / or C, 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" can be A only, B only, C only, A and B, A and C, B and C, or A and B and C, wherein any such combination may contain one or more members of A, B, or C. All structural and functional equivalents of components throughout the various aspects described in this disclosure are expressly incorporated herein by reference and are intended to be covered by the claims, and such structural and functional equivalents are well known or will be known to those skilled in the art. Furthermore, no disclosure herein is intended to be offered to the public, whether or not such disclosure is expressly stated in the claims. Terms such as "module," "apparatus," "element," "device," etc., are not substitutes for the term "unit." Therefore, the constituent elements of a claim should not be construed as functional modules unless the constituent element is expressly described using the term "functional module."

Claims

1. A method of wireless communication, comprising, at a first user equipment (UE): identifying a configuration for discontinuous reception (DRX) on sidelink communications; determining a plurality of channel busy ratio (CBR) measurement occasions based on the configuration for DRX, wherein determining the plurality of CBR measurement occasions comprises determining at least one CBR measurement occasion outside of an on-duration of the configuration for DRX; determining a CBR based on measurements of the plurality of CBR measurement occasions, wherein determining the CBR based on measurements of the plurality of CBR measurement occasions comprises waking up during the at least one CBR measurement occasion outside of the on-duration of the configuration for DRX to measure a received signal strength indicator (RSSI); and determining whether to perform congestion control for sidelink transmissions based on the CBR.

2. The method of claim 1, wherein, determining the plurality of CBR measurement occasions comprises determining that some of the plurality of CBR measurement occasions occur during an on-duration of the configuration for DRX.

3. The method of claim 1, wherein, the plurality of CBR measurement occasions are periodic.

4. The method of claim 1, wherein, the plurality of CBR measurement occasions are pseudo-random.

5. The method of claim 1, wherein, determining the CBR comprises filtering a plurality of CBR measurements based on filter coefficients applied to previous CBR values.

6. The method of claim 1, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement occasions are configured separately for each component carrier of the plurality of component carriers.

7. The method of claim 1, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement occasions are configured jointly for the plurality of component carriers.

8. The method of claim 1, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and wherein determining the CBR comprises determining the CBR based only on activated component carriers.

9. The method of claim 1, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and wherein determining the CBR comprises measuring an RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement occasions.

10. The method of claim 1, wherein, the plurality of CBR measurement occasions are configured by the first UE to include at least a minimum number of slots within a time window prior to a sidelink transmission.

11. An apparatus for wireless communication for a first user equipment (UE), comprising: a memory storing computer-executable instructions; and at least one processor coupled to the memory and configured to execute the computer-executable instructions to: identify a configuration for discontinuous reception (DRX) on sidelink communications; determine a plurality of channel busy ratio (CBR) measurement occasions based on the configuration for DRX; determine at least one CBR measurement occasion outside of an on-duration of the configuration for DRX; wake up during the at least one CBR measurement occasion outside of the on-duration of the configuration for DRX to measure a received signal strength indicator (RSSI); determining a CBR based on measurements of the plurality of CBR measurement occasions; and determining whether to perform congestion control for a sidelink transmission based on the CBR.

12. The apparatus of claim 11, wherein, the at least one processor is configured to determine that some of the plurality of CBR measurement occasions occur during an on-duration of the configuration for DRX.

13. The apparatus of claim 11, wherein, the plurality of CBR measurement occasions are periodic.

14. The apparatus of claim 11, wherein, the plurality of CBR measurement occasions are pseudo-random.

15. The apparatus of claim 11, wherein, determining the CBR includes filtering a plurality of CBR measurements based on filter coefficients applied to previous CBR values.

16. The apparatus of claim 11, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement occasions are configured separately for each component carrier of the plurality of component carriers.

17. The apparatus of claim 11, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and the plurality of CBR measurement occasions are configured jointly for the plurality of component carriers.

18. The apparatus of claim 11, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and wherein determining the CBR includes determining the CBR based only on activated component carriers.

19. The apparatus of claim 11, wherein, the first UE is configured with sidelink carrier aggregation for a plurality of component carriers, and wherein determining the CBR includes measuring RSSI on one or more inactive component carriers of the plurality of component carriers during the plurality of CBR measurement occasions.

20. The apparatus of claim 11, wherein, the plurality of CBR measurement occasions are configured by the first UE to include at least a minimum number of slots within a time window prior to a sidelink transmission.

21. A computer-readable medium storing computer-executable instructions for wireless communication by a first user equipment (UE), the computer-executable instructions for performing steps of the method of any of claims 1-10.

22. An apparatus for wireless communication by a first user equipment (UE), comprising: means for performing steps of the method of any of claims 1-10. means for performing steps of the method of any of claims 1-10.

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