Channel busyness measurement in sidelink communication

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) communicating via a sidelink in an unlicensed spectrum may perform channel congestion control based on channel busy measurements. For example, the UE may perform channel busy measurements on different resource sets to identify congestion levels from different radio access technologies (RATs). The UE may perform a first channel busy measurement on a first resource set, wherein the first resource set contains resources where the sidelink UE is configured to suspend transmission, and the UE may perform a second channel busy measurement on a second resource set when the sidelink UE and wireless devices of other RATs may freely compete for resources and transmit. The UE may perform a third channel busy measurement on a third resource set, wherein the third resource set contains resources where contention-based access was successful.

Description

Technical Field

[0001] The following relates generally to wireless communications, and more particularly, to channel busyness measurement in a sidelink. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, etc. These systems can support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems, such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems, which may be referred to as new radio (NR) systems. These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each of which simultaneously supports communication for multiple communication devices, which may also be referred to as user equipment (UE).

[0003] In some wireless communication systems, two or more devices may attempt to conduct sidelink communications in an unlicensed spectrum. Sidelink communications may use channel busy measurements, such as channel busy rate (CBR), as a metric for congestion control. When operating in an unlicensed spectrum, the channel busy measurements may measure components from other radio access technologies (RATs), such as Wi-Fi, in addition to components from sidelink UE signals. Therefore, relying on channel busy measurements performed in this manner may not accurately represent sidelink traffic congestion, and may therefore result in inaccurate sidelink congestion control in the unlicensed spectrum. Summary of the invention

[0004] The described technology relates to improved methods, systems, devices and apparatuses for supporting channel busy measurements in sidelink communications. In general, the described technology enables a user equipment (UE) communicating via a sidelink in an unlicensed spectrum to perform channel congestion control by performing channel busy measurements on different resource sets to identify congestion levels from different radio access technologies (RATs). For example, a first UE may perform a first channel busy measurement on a first resource set, wherein the first resource set contains resources in which the sidelink UE is configured to suspend transmission. When the sidelink UE and wireless devices of other RATs can freely compete for resources and transmit, the first UE may perform a second channel busy measurement on a second resource set. The first UE may perform a third channel busy measurement on a third resource set, wherein the third resource set contains resources in which contention-based access is successful. The first UE may configure communication parameters for congestion control based at least in part on the first channel busy measurement, the second channel busy measurement, and the third channel busy measurement, individually or in combination.

[0005] A method of wireless communication at a first UE is described. The method may include: identifying a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busy measurement that is not affected by sidelink traffic, suspending sidelink transmission during the identified resource set, performing channel busy measurement for the resource set while suspending sidelink transmission, and communicating with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0006] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: identify a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busy measurement without side link traffic, suspend side link transmission during the identified resource set, perform channel busy measurement for the resource set while suspending side link transmission, and communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0007] Another apparatus for wireless communication at a first UE is described. The apparatus may include components for identifying a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busy measurement without sidelink traffic, suspending sidelink transmission during the identified resource set, performing channel busy measurement for the resource set while suspending sidelink transmission, and communicating with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0008] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to: identify a resource set of an unlicensed radio frequency spectrum band, the resource set configured for channel busy measurement without sidelink traffic, suspend sidelink transmission during the identified resource set, perform channel busy measurement for the resource set while suspending sidelink transmission, and communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0009] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for selecting a channel of an unlicensed radio frequency spectrum band for communicating with a second UE based on determining that a congestion level of the channel satisfies a congestion threshold.

[0010] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for selecting a channel of an unlicensed radio frequency spectrum band for communicating a side link message with a second UE based on determining that the priority of the side link message satisfies a priority threshold.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for selecting a channel in an unlicensed radio frequency spectrum band for communicating with a second UE independent of a congestion level of a given channel satisfying a congestion threshold.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the priority threshold corresponds to a service type of the sidelink message.

[0013] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing channel busy measurements may include operations, features, components, or instructions for determining a measurement window configured for measurements that may be free of sidelink traffic and measuring one or more channel parameters over the measurement window and resource set.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, one or more channel parameters include a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal to interference plus noise ratio (SINR), or any combination thereof.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for determining an effective bandwidth portion for sidelink communication between a UE and a second UE and performing a channel busy measurement on at least one subcarrier excluded from the effective bandwidth portion.

[0016] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for determining a second resource set of an unlicensed radio frequency spectrum band, the second resource set being configured for a channel busy measurement that may be associated with a sidelink service, performing a second channel busy measurement for the second resource set, and selecting a channel of the unlicensed radio frequency spectrum band for communicating with a second UE based on the second channel busy measurement.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, performing a second channel busy measurement may include operations, features, components, or instructions for performing a second channel busy measurement on resources in a second set of resources that may not overlap with a set of resources.

[0018] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for determining a set of communication parameters for sidelink communication based on the channel busy measurement and the second channel busy measurement and communicating with the second UE using the communication parameter set.

[0019] In some examples of methods, apparatus, and non-transitory computer-readable media described herein, determining a communication parameter set may include operations, features, components, or instructions for determining a difference between a channel busy measurement and a second channel busy measurement and selecting a communication parameter set based on the difference.

[0020] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the set of communication parameters includes a modulation and coding scheme (MCS), a transmit power, a number of retransmissions, a number of subchannels, a coding rate, or any combination thereof.

[0021] A method of wireless communication at a first UE is described. The method may include monitoring each resource in a resource set of an unlicensed radio frequency spectrum band associated with a sidelink communication, determining one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access process based on the monitoring, performing channel busy measurement for each of the one or more resources, and communicating with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0022] An apparatus for wireless communication at a first UE is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: monitor each resource in a resource set of an unlicensed radio frequency spectrum band associated with a sidelink communication, determine one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access process based on the monitoring, perform channel busy measurement for each of the one or more resources, and communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0023] Another apparatus for wireless communication at a first UE is described. The apparatus may include components for monitoring each resource in a resource set of an unlicensed radio frequency spectrum band associated with sidelink communication, determining one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access procedure based on the monitoring, performing channel busy measurement for each of the one or more resources, and communicating with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0024] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor to: monitor each resource in a resource set of an unlicensed radio frequency spectrum band associated with sidelink communication, determine one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access procedure based on the monitoring, perform channel busy measurement for each of the one or more resources, and communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0025] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for detecting sidelink control information in each of one or more resources based on monitoring, wherein one or more resources in a resource set may be determined based on detecting the sidelink control information.

[0026] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the sidelink control information may be associated with a transmitting UE other than the first UE.

[0027] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for determining a window of a set of resources spanning an unlicensed radio frequency spectrum band associated with sidelink communications, wherein a channel busyness measurement may be performed for each of one or more resources within the window.

[0028] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the window corresponds to a quantity of the set of resources.

[0029] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the window corresponds to a quantity of one or more resources.

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may further include operations, features, components, or instructions for performing channel sensing in each resource in a resource set based on monitoring, wherein one or more resources of the resource set may be determined based on successful channel sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 An example of a wireless communication system supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown.

[0032] Figure 2 An example of a wireless communication system supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown.

[0033] Figure 3 An example of a wireless communication channel supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown.

[0034] Figure 4 An example of a wireless communication channel supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown.

[0035] Figure 5 An example of a process flow to support channel busy measurement in sidelink communications according to aspects of the present disclosure is shown.

[0036] Figure 6 An example of a process flow to support channel busy measurement in sidelink communications according to aspects of the present disclosure is shown.

[0037] Figure 7 and Figure 8 A block diagram of an apparatus supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown.

[0038] Fig. 9A block diagram of a communication manager supporting channel busy measurements in sidelink communications is shown in accordance with aspects of the present disclosure.

[0039] Fig.10 A diagram of a system including a device supporting channel busyness measurement in sidelink communications is shown in accordance with aspects of the present disclosure.

[0040] Figures 11 to 17 A flow chart illustrating a method of supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0041] In some wireless communication systems, two or more devices may attempt to conduct sidelink communications in an unlicensed spectrum. Sidelink communications may suffer from performance degradation under increased channel load, and the user equipment (UE) may use congestion control mechanisms to mitigate conflicts. The congestion control mechanism may configure one or more transmission parameters, such as the modulation and coding scheme (MCS) index and MCS table, the number of subchannels per transmission, the number of retransmissions, the transmit power, and the channel occupancy limit.

[0042] Sidelink communications may use channel busyness measurements such as channel busyness rate (CBR) as a metric for congestion control. Channel busyness measurements may be performed by measuring the level of channel congestion on a set of resources prior to the measurement. Channel busyness measurements may be based on a received signal strength indicator (RSSI) measured on a given channel (e.g., a sidelink channel).

[0043] When operating in an unlicensed spectrum, channel busy measurements may include signal components from other radio access technology (RAT) communications (such as Wi-Fi communications) in addition to signal components from sidelink UE components within the coverage area. Therefore, reliance on channel busy measurements performed in this manner may not accurately represent sidelink traffic congestion and may therefore result in inaccurate sidelink congestion control in the unlicensed spectrum.

[0044] The UE may perform additional channel busy measurements on different sets of resources to differentiate between congestion levels from sidelink UEs and other RATs. Additional sidelink channel busy measurements may include measuring different RSSI measurement resources, reports, and thresholds. Additional channel busy measurements may be used alone or in combination to inform congestion control.

[0045] The first channel busy measurement may measure the congestion level of wireless devices operating using other RATs such as Wi-Fi. The first channel busy measurement may be performed on a first resource set consisting of resources when the sidelink UE is not transmitting. The measurement window for the first resource set may be configured for the UE to perform the channel busy measurement when the sidelink UE is not transmitting. In addition, the first resource set may include a plurality of listen-before-talk (LBT) subbands, carriers, and channels other than the listen-before-talk (LBT) subbands, carriers, and channels included in the effective sidelink bandwidth portion.

[0046] A second channel busy measurement may be performed to estimate the total congestion on the channel from the sidelink UE and from wireless devices operating in other RATs (such as Wi-Fi). When the sidelink UE and other RAT devices are free to compete and transmit signals, a second channel busy measurement may be performed on a second resource set consisting of resources. In addition to interference from other RATs (including Wi-Fi), the second channel busy measurement may also capture UE interference within the sidelink. In some examples, the second resource set may include a fixed number of resources before the measurement slot. In some examples, the second resource set may be a sliding window of resources with a fixed duration (i.e., 100ms) before the channel busy measurement. In some examples, the second resource set may be a fixed number of resources (i.e., 100 time slots) before the channel busy measurement. In some examples, the second resource set may include or overlap resources included in the first resource set. In some examples, the second resource set may exclude resources included in the first resource set.

[0047] A third channel busy measurement may be performed on a resource with an indication of contention-based access success. In some cases, measuring a channel busy measurement on a resource with an indication of contention-based access success may provide an indication of channel congestion in the resource, i.e., the side link UE is not blocked by a wireless device operating with other RATs (such as Wi-Fi). In some cases, the third channel busy measurement may measure congestion from the side link UE. In some cases, the third channel busy measurement may measure channel congestion in a resource where the side link UE wins contention-based access. In some cases, the UE may perform a contention-based access process to determine a resource with contention-based access success. In some cases, the UE may determine contention-based access success by detecting an indication of contention-based access success of other side link UEs. In some cases, contention-based access success may be determined based on the detection of side link control information (SCI). For the third channel busy measurement, the UE may consider resources with at least one SCI detection for measurement. In some cases, if the UE does not decode any SCI from any transmitting UE for a given resource, the UE may omit the resource for the third channel busy measurement. In some cases, the first channel busy measurement may be used to determine inter-RAT congestion. If the first channel busy measurement indicates channel congestion, the UE may switch to a different LBT subband, carrier, or channel. Determining to switch to a different LBT subband, carrier, or channel may be based in part on the first channel busy measurement satisfying a threshold. The threshold for the UE to switch to a different LBT subband, carrier, or channel may depend on the service priority of the UE. The service priority of the device may depend on the device. The service priority of the device may be dynamically allocated, semi-dynamically allocated, or permanently allocated. Additionally or alternatively, the threshold for the UE to switch to a different LBT subband, carrier, or channel may depend on the service priority of the communication service. For example, the UE may use a lower channel busy measurement threshold for high priority services and a higher channel busy measurement threshold for low priority services.

[0048] In some examples, the first channel busy measurement can be used in combination with the second channel busy measurement to inform congestion control. The network can be configured based on both the first channel busy measurement and the second channel busy measurement, or the UE can determine the congestion control mechanism based on both the first channel busy measurement and the second channel busy measurement, such as but not limited to MCS restrictions, transmit power restrictions, retransmission number restrictions, the number of subchannels sent each time, and channel occupancy restrictions. For example, when the first channel busy measurement is low, the second channel busy measurement can accurately reflect the operator's internal side link UE congestion. In this case, the congestion control mechanism can be satisfactorily configured or determined based only on the second channel busy measurement. In other examples, when the first channel busy measurement is high, the channel may be generally loaded, and the congestion may not be caused by side link UE communication. In this case, congestion control based only on the second channel busy measurement may not be accurate, and it may be beneficial to use the first channel busy measurement and the second channel busy measurement in combination to inform congestion control. Additionally or alternatively, the UE can perform congestion control based on the third channel busy measurement alone or in combination. Furthermore, the first channel busy measurement, the second channel busy measurement, and the third channel busy measurement may be used for congestion control alone or in combination.

[0049] Various aspects of the disclosure are first described in the context of a wireless communication system. Various aspects of the disclosure are further disclosed in the context of a communication channel and a process flow. Various aspects of the disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow charts related to channel busy measurements in sidelink communications.

[0050] Figure 1 An example of a wireless communication system 100 supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low-latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

[0051] The base stations 105 may be dispersed throughout a geographic area to form the wireless communication system 100 and may be devices of different forms or capabilities. The base stations 105 and the UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base stations 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which the base stations 105 and the UEs 115 may support communication of signals according to one or more radio access technologies.

[0052] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile or both at different times. The UEs 115 may be devices of different forms or with different capabilities. Figure 1 Some example UEs 115 are shown in FIG. 1. The UEs 115 described herein can communicate with various types of devices, such as other UEs 115, base stations 105, or network devices (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network devices), such as Figure 1 shown.

[0053] Base stations 105 may communicate with core network 130, or with each other, or both. For example, base stations 105 may interface with core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). Base stations 105 may communicate with each other directly (e.g., directly between base stations 105) or indirectly (e.g., via core network 130), or both via backhaul links 120 (e.g., via X2, Xn, or other interfaces). In some examples, backhaul links 120 may be or include one or more wireless links.

[0054] One or more of the base stations 105 described herein may include or may be referred to by one of ordinary skill in the art as a transceiver base station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next generation NodeB or a giga-NodeB (any of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or some other suitable term.

[0055] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where a "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, among other examples, which may be implemented in various objects such as appliances or vehicles, meters, etc.

[0056] The UE 115 described herein may be able to communicate with various types of devices, such as other UEs 115, sometimes acting as relays, as well as base stations 105 and network devices including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, such as Figure 1 shown.

[0057] The UE 115 and the base station 105 can communicate with each other wirelessly via one or more communication links 125 through one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating operations for the carrier, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, the UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation may be used with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0058] The signal waveform transmitted on the carrier may be composed of multiple subcarriers (e.g., using multicarrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Therefore, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate for UE 115. Wireless communication resources may refer to a combination of RF spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may further improve the data rate or data integrity of communications with UE 115.

[0059] The time interval of the base station 105 or the UE 115 may be expressed as a multiple of a basic time unit, which may be, for example, T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the maximum supported subcarrier spacing, and N f The maximum supported discrete Fourier transform (DFT) size may be indicated. The time intervals of the communication resources may be organized according to radio frames, each radio frame having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0060] Each frame may include multiple consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, the frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into multiple time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include multiple symbol periods (e.g., depending on the length of the cyclic prefix appended to each symbol period). In some wireless communication systems 100, the time slot may be further divided into multiple micro-time slots containing one or more symbols. In addition to the cyclic prefix, each symbol period may contain one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0061] A subframe, a time slot, a mini-time slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI)).

[0062] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) of a physical control channel may be defined by a plurality of symbol periods and may extend across a system bandwidth or a subset of a system bandwidth of a carrier. One or more control regions (e.g., CORESETs) may be configured for a group of UEs 115. For example, one or more of the UEs 115 may monitor or search a control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates at one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate may refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information of a control information format having a given payload size. A search space set may include a common search space set configured for sending control information to a plurality of UEs 115, and a UE-specific search space set for sending control information to a specific UE 115.

[0063] In some examples, base stations 105 may be mobile and, therefore, provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0064] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. UE115 can be designed to support ultra-reliable, low-latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private communication or group communication, and can be supported by one or more mission-critical services, such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions may include prioritization of services, and mission-critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency can be used interchangeably in this article.

[0065] In some examples, the UE 115 is also able to communicate directly with other UEs 115 via a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105, or otherwise unable to receive transmissions from the base station 105. In some examples, a group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group. In some examples, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between UEs 115 without the involvement of the base station 105.

[0066] In some systems, the D2D communication link 135 can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these. Vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some examples, vehicles in a V2X system can communicate with roadside infrastructure (such as roadside units), or communicate with a network using vehicle-to-network (V2N) communication via one or more network nodes (e.g., base station 105), or can communicate with both.

[0067] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) and at least one user plane entity that routes or interconnects packets to an external network (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)). The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UE 115 served by a base station 105 associated with the core network 130. User IP packets may be delivered through a user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to a network operator IP service 150. The operator's IP service 150 may include access to the Internet, (one or more) intranets, an IP multimedia subsystem (IMS), or a packet-switched streaming service.

[0068] Some network devices such as base stations 105 may include subcomponents such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with UE 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). Each access network transmission entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs), or merged into a single network device (e.g., base station 105).

[0069] The wireless communication system 100 may operate using one or more frequency bands typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Typically, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately 1 decimeter to 1 meter long. UHF waves may be blocked or redirected by buildings and environmental features, but these waves may penetrate structures sufficiently for a macro cell to serve a UE 115 located indoors. Transmission of UHF waves may be associated with smaller antennas and a shorter range (e.g., less than 100 kilometers) than transmission using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHZ.

[0070] The wireless communication system 100 can utilize licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 can use license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in unlicensed bands such as the industrial, scientific, and medical (ISM) band of 5 GHz. When operating in an unlicensed radio frequency spectrum band, devices such as base stations 105 and UEs 115 can use carrier sensing for conflict detection and avoidance. In some examples, operations in unlicensed bands can be based on a combination of carrier aggregation configurations and component carriers operating in licensed bands (e.g., LAA). Operations in unlicensed spectrum can include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, as well as other examples.

[0071] The base station 105 or UE 115 may be equipped with multiple antennas, which may be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the base station 105 or UE 115 may be located in one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array with multiple rows and columns of antenna ports, which the base station 105 may use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. In addition or alternatively, the antenna panel may support radio frequency beamforming for signals sent via the antenna ports.

[0072] Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape an antenna beam (e.g., a transmit beam, a receive beam) or steer an antenna beam along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating in a particular direction relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to a signal carried via an antenna element associated with the device. Adjustments associated with each antenna element may be defined by a set of beamforming weights associated with a particular direction (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other direction).

[0073] UE 115 may perform additional channel busy measurements on different sets of resources to distinguish between the congestion level from the sidelink UE 115 and the congestion level from other RATs. The additional measurements may include different RSSI measurement resources, reports, and thresholds. A first additional channel busy measurement may be performed when the sidelink UE within the network is not transmitting. The channel busy measurement may measure interference from other RATs (such as Wi-Fi). A second channel busy measurement may be performed when the sidelink UE can freely compete and send a sidelink signal for other sidelink UEs 115 to measure. The second channel busy measurement may capture interference from the sidelink UE 115 and interference from other RATs (including Wi-Fi). A third channel busy measurement may be contention-based access sensing, where the channel busy measurement is measured within a resource with an indication of contention-based access success.

[0074] The first channel busy measurement, the second channel busy measurement, and the third channel busy measurement can be used for congestion control alone or in combination. Based on these channel busy measurements, UE 115 can determine communication parameters for sidelink communication, such as MCS, transmit power, etc. For example, if the first channel busy measurement is low, the second channel busy measurement can accurately reflect the channel congestion from UE 115 communication. In this case, congestion control can be satisfactorily performed based on the second channel busy measurement. Alternatively, if the first channel busy measurement is high, the channel may be loaded generally and may not be just due to UE 115 communication. In this case, congestion control based only on the second channel busy may be inaccurate.

[0075] Figure 2 An example of a wireless communication system 200 that supports channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 can include UE 115-a, UE 115-b, UE 115-c, and UE 115-d, which can be referenced Figure 1 An example of a corresponding UE 115 is described.

[0076] UE 115-a may attempt to establish a communication link 210 with UE 115-b over a sidelink channel in an unlicensed spectrum. For communication on the sidelink channel, UE 115-a may contend for sidelink resources with other UEs 115 in coverage area 205, such as UE 115-c. UE 115-c may send sidelink transmissions 215 in the unlicensed spectrum. UE 115-a may also contend with wireless devices operating using a different RAT, such as Wi-Fi UE 115-d, for communication on the sidelink channel in the unlicensed spectrum. Wi-Fi UE 115-d may send Wi-Fi transmissions 220. Sidelink transmissions 215 and Wi-Fi transmissions 220 may cause channel congestion or interference in coverage area 205.

[0077] For operations in an unlicensed radio frequency spectrum, the UE 115-a may perform an interference management process to determine whether a channel is available for use. For example, the UE 115-a may perform a channel access process. The channel access process may be a contention-based access process. In some cases, the channel access process may be a listen-before-talk (LBT) process, or a clear channel assessment (CCA), etc. The UE 115-a may monitor the channel for a period of time to determine whether the channel is occupied or available for use. The UE 115-a may monitor the energy and / or waveform of the channel to determine whether the channel is available for use. If the channel access process determines that the side link transmission 215 or the Wi-Fi transmission 220 occupies the monitored channel, the UE 115-a performs an interference management process.

[0078] Additionally or alternatively, UE 115-a may perform congestion control to coordinate the use of the channel. Congestion control may configure a set of communication parameters to control the level of congestion on the channel. Communication parameters that may be configured include, but are not limited to, MCS index and MCS table, number of subchannels per transmission, number of retransmissions, transmit power and channel occupancy limits, coding rate, or any combination thereof.

[0079] UE 115-a may use channel busy measurements as a metric for congestion control. UE 115-a may determine whether a congestion level of a channel meets a congestion threshold based at least in part on the channel busy measurements. The channel busy measurements may include or be based on, but are not limited to, CBR, RSSI, reference signal received power (RSRP), reference signal quality (RSRQ), signal to interference plus noise ratio (SINR), or any combination thereof.

[0080] In some examples, UE 115-a may perform a first channel busy measurement to notify a congestion control function. UE 115-a may perform a first channel busy measurement to measure channel congestion based on signals from devices operating in other RATs, such as Wi-Fi transmission 220 from Wi-Fi UE 115-d. UE 115-a may perform a first channel busy measurement when UE 115 is not transmitting. The first channel busy measurement may be performed on a first measurement resource set. The first measurement resource set may be defined such that UE 115 may be preconfigured to not transmit during resources associated with the first measurement resource set. UE 115-a, 115-b, and 115-c may suspend transmission during the first measurement resource set. UE 115-a may be preconfigured to perform a first channel busy measurement on resources associated with the first measurement resource set.

[0081] In some examples, UE 115-a may perform a second channel busy measurement to inform the congestion control function. UE 115-a may perform a second congestion control measurement to measure the total channel congestion from devices operating in coverage area 205. For example, the second channel busy measurement may determine channel congestion from UE 115-c and Wi-Fi UE 115-d. UE 115-a may perform a second channel busy measurement on a second measurement resource set. The second measurement resource set may include resources for which UE 115-c and Wi-Fi UE 115-d may freely compete for resources and transmit signals. The second measurement resource set may be a fixed number of resources for measurement. For example, the second measurement resource set may be sensed over 100 time slots for measurement. In some cases, the second measurement resource set may be a sliding measurement window. In some cases, the second measurement resource set may include resources included in the first measurement resource set. In some cases, the second measurement resource set may exclude resources included in the first measurement resource set.

[0082] In some examples, UE 115-a may perform a third channel busy measurement to notify the congestion control function. The third channel busy measurement may measure channel congestion in a resource with an indication of contention-based access success. UE 115-a may determine whether the first resource has contention-based access success by passing a medium sensing using clear channel assessment (CCA) or extended CCA (eCCA), or by monitoring the presence of SCI information from one or more other UEs 115 (such as UE 115-c). In some cases, if UE 115-a detects SCI in the first resource, UE 115-a may determine to perform channel busy measurement on the first resource. In some cases, UE 115-a may include the first resource in the third resource set. If UE 115-a does not detect SCI in the second resource and additionally does not pass CCA / eCCA, UE 115-a may determine not to perform channel busy measurement on the second resource. In some cases, UE 115-a may determine to exclude the second resource from the third resource set. If UE 115-a does not detect SCI in the third resource but passes CCA / eCCA, UE 115-a may determine to perform channel busy measurement on the third resource. In some cases, UE 115-a may include the third resource in the third resource set. In some examples, UE 115-a may perform channel busy measurement on resources with an indication of successful contention-based access within the measurement window. In some examples, UE 115-a may perform channel busy measurement on resources included in the third resource set within the measurement window. For example, UE 115-a may perform channel busy measurement on 100 or 100×2 μ In some examples, UE 115-a may perform channel busy measurements on a fixed number of resources with contention-based access successes for which measurements are taken. For example, UE 115-a may perform channel busy measurements on 100 or 100×2 resources with contention-based access successes for which measurements are taken. μ Channel busy measurements are performed in each time slot.

[0083] In some examples, UE 115-a may use one or more of the first channel busy measurement, the second channel busy measurement, and the third channel busy measurement, alone or in combination, to notify a channel congestion control function. In some examples, UE 115-a may be configured to determine communication parameters for congestion control based only on the execution of the first channel busy measurement, the second channel busy measurement, or the third channel busy measurement. In some examples, UE 115-a may determine communication parameters for congestion control based on a combination of at least two of the first channel busy measurement, the second channel busy measurement, and the third channel busy measurement. For example, UE 115-a may perform a first channel busy measurement and a second channel busy measurement, and configure channel communication parameters for congestion control based on the measurement. In some examples, UE 115-a may determine to perform one or more of the first channel busy measurement, the second channel busy measurement, or the third channel busy measurement based on one or more indications of channel congestion. For example, if UE 115-a does not detect sufficient resources to meet a threshold within a measurement window with an indication of successful contention-based access, the UE may perform at least one of the first channel busy measurement and the second channel busy measurement to notify congestion control.

[0084] Figure 3 An example of a wireless communication channel 300 that supports channel busy measurements in sidelink communications in accordance with aspects of the present disclosure is shown. In some examples, the wireless communication channel 300 may be an example of a wireless communication channel implemented in aspects of the wireless communication system 100 and the wireless communication system 200. The wireless communication channel 300 may be on a frequency band 305, which may be a frequency band in an unlicensed radio frequency spectrum. The sidelink UE 115 may compete with other sidelink UEs 115 and Wi-Fi UEs 115 for resources in the frequency band 305. The sidelink UE 115 may perform congestion control to manage communication traffic on the frequency band 305. According to aspects of the present disclosure, the sidelink UE 115 may perform channel busy measurements on the frequency band 305 to inform the congestion control function.

[0085] UE 115 may perform a channel busy measurement at measurement time slot 320-a.UE 115 may perform a first channel busy measurement on a first measurement resource set 315-a, and UE 115 may perform a second channel busy measurement on a second measurement resource set 310-a.

[0086] The first measurement resource set 315-a may include resources in which the sidelink UE 115 is configured not to transmit. The first measurement resource set 315-a may include resources that include signals from wireless devices operating with other RATs, such as Wi-Fi UE 115-d. The first measurement resource set 315-a includes any number of resources, and these resources may appear at any time. The first measurement resource set may appear in a preconfigured pattern and may appear at a pre-set period. The number of resources included in the first measurement resource set 315-a and the timing of the resources may be preconfigured. The sidelink UE 115 may be aware of the preconfiguration of the first measurement resource set 315.

[0087] The second measurement resource set 310-a may include resources in which the sidelink UE 115 and wireless devices operating with other RATs (such as Wi-Fi UE 115-d) can freely compete for resources and send signals. In some examples, the second measurement resource set 310-a may include the first measurement resource set 315-a. In some examples, the second measurement resource set 310-a may exclude the first measurement resource set 315-a. The second measurement resource set 310-a may be configured as a sliding window with a fixed number of resources. The fixed number of resources can be any number of resources. For example, the second measurement resource set 310-a may include 100 time slots immediately after the channel busy measurement. In another example, the second measurement resource set 310-a may include 100 time slots immediately after the channel busy measurement and exclude the first measurement resource set.

[0088] In some examples, UE 115 can perform channel busy measurements on any resource in frequency band 305. For example, UE 115 can perform a first channel busy measurement on a first measurement resource set 315-a at measurement time slot 320-a, and perform a second channel busy measurement on a second measurement resource set 310-a at measurement time slot 320-a. Similarly, UE 115 can perform a first channel busy measurement on a first measurement resource set 315-b at measurement time slot 320-b, and perform a second channel busy measurement on a second measurement resource set 310-b at measurement time slot 320-b. Alternatively, sidelink UE 115 can be configured to perform channel busy measurements in defined resources.

[0089] Figure 4An example of a wireless communication channel 400 that supports channel busy measurements in sidelink communications in accordance with aspects of the present disclosure is shown. In some examples, the wireless communication channel 400 may be an example of a communication channel implemented in aspects of the wireless communication system 100 and the wireless communication system 200. The wireless communication channel 400 may be on a frequency band 405, which may be a frequency band in an unlicensed radio frequency spectrum. The sidelink UE 115 may compete with other sidelink UEs 115 and Wi-Fi UEs 115 for resources on the frequency band 405. The sidelink UE 115 may perform congestion control to manage communication traffic on the frequency band 405. According to aspects of the present disclosure, the sidelink UE 115 may perform channel busy measurements on the frequency band 405 to inform the congestion control function.

[0090] In some examples, the first UE 115 may monitor the band 405 to determine channel congestion in resources that other sidelink UEs 115 are using to communicate. The first UE 115 may determine which resources other sidelink UEs 115 are using to communicate by monitoring the band 405 to obtain resources with contention-based access success. The first UE may determine resources with contention-based access success by monitoring resources in the band 405 to obtain SCI indications from other sidelink UEs 115 in the coverage area 205. The UE 115 may identify resources with contention-based access success in the measurement window 410-a by determining which resources in the measurement window 410-a contain indications of the SCI. The UE 115 may perform channel busy measurements on resources with contention-based access success in the measurement window 410.

[0091] The first UE 115 may perform a channel busy measurement at the measurement time slot 420-a. The UE 115 may perform a channel busy measurement on a subset of resources with contention-based access success within the measurement window 410-a based at least in part on the detection of an indication of contention-based access success.

[0092] In some examples, a channel busy measurement performed at measurement slot 420-a may be measured on a subset of resources within measurement window 410-a. Measurement window 410-a may have a preconfigured length. For example, measurement window 410-a may be defined as 100 slots prior to measurement slot 420-a. In this example, a channel busy measurement performed at measurement slot 420-a may be measured on resources within a subset of resources within 100 slots prior to measurement slot 420-a. Similarly, a channel busy measurement performed at measurement slot 420-b may be measured on a subset of resources within 100 slots prior to measurement slot 420-b.

[0093] Alternatively, the first UE 115 may perform channel busy measurements on a fixed number of resources within a resource subset prior to measurement slot 420-a. For example, the sidelink UE may perform channel busy measurements on 100 time slots within a resource subset prior to measurement slot 420-a. This approach may estimate channel congestion on a fixed sample size.

[0094] The first UE 115 may perform channel busy measurements on any resource on the frequency band 405. For example, the UE 115 may perform channel busy measurements at the measurement time slot 420-a based on resources with contention-based access success within the measurement window 410-a. Similarly, the first UE 115 may perform channel busy measurements at the measurement time slot 420-b based on resources with contention-based access success within the measurement window 410-b. Alternatively, the first sidelink UE 115 may be configured to perform channel busy measurements in defined resources.

[0095] Figure 5 An example of a process flow 500 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. In some examples, the process flow 500 can implement aspects of the wireless communication system 100 and the wireless communication system 200. The UE 115-e and the UE 115-f can be as described in reference Figure 1 and Figure 2 An example of a described UE 115. Process flow 500 illustrates an example of a process by which UE 115-e may send a message to UE 115-f via sidelink communications.

[0096] At 505, UE 115-e may identify a resource set of an unlicensed radio frequency spectrum band that is configured for channel busy measurement without side link traffic. UE 115-e may be configured with a resource set without side link traffic. UE 115-f may also be configured with a resource set without side link traffic.

[0097] At 510, UE 115-e may suspend sidelink transmissions during the set of resources identified at 505. UE 115-f may also suspend sidelink transmissions during the set of resources identified at 505.

[0098] At 515, the UE 115-e may perform a first channel busy measurement on the set of resources identified at 505. The first channel busy measurement may be performed by measuring one or more channel parameters on the set of resources determined at 505. The channel parameters may include, but are not limited to, RSSI, RSRP, RSRQ, SINR.

[0099] At 520, the UE 115-e may determine a second resource set of the unlicensed radio frequency spectrum band, wherein the second resource set is configured for channel busyness measurement associated with the sidelink service. The second resource set may not overlap with the resource set determined at 505.

[0100] At 525, the UE 115-e may perform a second channel busy measurement on the second set of resources determined at 520. The channel busy measurement may be performed by measuring one or more channel parameters on the set of resources determined at 520. The channel parameters may include, but are not limited to, RSSI, RSRP, RSRQ, SINR.

[0101] At 530, UE 115-e may communicate with UE 115-f via a channel of an unlicensed radio frequency spectrum band based at least in part on the channel busy measurement performed at 515. In some examples, UE 115-e may configure a set of communication parameters for sidelink communication based at least in part on the channel busy measurement determined at 515. In some examples, UE 115-e may configure a set of communication parameters for sidelink communication based at least in part on the channel busy measurement determined at 515 and a second channel busy measurement performed at 525. The set of communication parameters may include congestion control parameters. Congestion control parameters may include modulation and coding schemes, transmit power, number of retransmissions, number of subchannels, coding rate, or any combination thereof. In some examples, UE 115-e may select a channel of an unlicensed radio frequency spectrum band for communicating with UE 115-f based at least in part on determining that the congestion level of the channel satisfies a congestion control threshold. In some examples, UE 115-e may select a channel of an unlicensed radio frequency spectrum band for communicating the sidelink message with UE 115-f based at least in part on determining a priority of the sidelink message and further determining that the priority of the sidelink message satisfies a priority threshold. In some examples, UE 115-e may select a channel of an unlicensed radio frequency spectrum band for communicating with UE 115-f independent of a congestion level of the channel determined at 515.

[0102] Figure 6 An example of a process flow 600 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. In some examples, the process flow 600 may implement aspects of the wireless communication system 100 and the wireless communication system 200. The UE 115-g and the UE 115-h may be as described in reference Figure 1 and Figure 2 An example of a described UE 115. Process flow 600 illustrates an example of a process by which UE 115-g may send a message to UE 115-h via sidelink communications.

[0103] At 605, UE 115-g may monitor resources of an unlicensed radio frequency spectrum band associated with sidelink communications. UE 115-g may monitor resources of an unlicensed radio frequency spectrum band to determine a congestion level on the band. UE 115-g may determine the congestion level on the band in order to perform congestion control. UE 115-g may perform congestion control by adjusting communication parameters associated with congestion control.

[0104] At 610, the UE 115-g may determine resources for channel busy measurements, where each resource corresponds to a successful contention-based access process based at least in part on the monitoring at 605. The UE 115-g may perform congestion control based on measuring congestion levels in resources that other sidelink UEs 115 in the coverage area are using for communication, and ignoring congestion levels of resources dominated by other RATs. The UE 115-g may determine the resources that the sidelink UE 115 is using for communication based on the detection of an indication of contention-based access success. The UE 115-g may determine the resources with contention-based access success by detecting an indication of an SCI. The UE 115-g may determine the resources on which to perform channel busy measurements based on the detection of the SCI.

[0105] At 615, the UE 115-g may perform channel busy measurements on the one or more resources determined at 610. The channel busy measurements may be performed by measuring one or more channel parameters on the set of resources determined at 610. The channel parameters may include, but are not limited to, RSSI, RSRP, RSRQ, SINR.

[0106] At 620, UE 115-g may communicate with UE 115-h via a channel of an unlicensed radio frequency spectrum band based at least in part on the channel busy measurement performed at 615. In some examples, UE 115-g may configure a set of communication parameters for sidelink communication based at least in part on the channel busy measurement performed at 615. The set of communication parameters may include congestion control parameters. The congestion control parameters may include modulation and coding schemes, transmit power, number of retransmissions, number of subchannels, decoding rate, or any combination thereof. In some examples, UE 115-g may select a channel of an unlicensed radio frequency spectrum band for communicating with UE 115-h based at least in part on determining that the congestion level of the channel meets a congestion control threshold. In some examples, UE 115-g may select a channel of an unlicensed radio frequency spectrum band for communicating a sidelink message to UE 115-h based at least in part on determining a priority of the sidelink message and further determining that the priority of the sidelink information meets a priority threshold. In some examples, UE 115-g may select a channel in an unlicensed radio frequency spectrum band for communicating with UE 115-h independently of the congestion level of the channel determined at 615.

[0107] Figure 7 A block diagram 700 of a device 705 supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The device 705 may be an example of aspects of a UE 115 as described herein. The device 705 may include a receiver 710, a communication manager 715, and a transmitter 720. The device 705 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0108] The receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to channel busyness measurements in sidelink communications, etc.). The information may be passed to other components of the device 705. The receiver 710 may be a reference Fig.10 Examples of aspects of the described transceiver 1020. The receiver 710 may utilize a single antenna or a collection of antennas.

[0109] The communication manager 715 can: identify a resource set of an unlicensed radio frequency spectrum band, which resource set is configured for channel busy measurement without side link traffic, suspend side link transmission during the identified resource set, perform channel busy measurement for the resource set while suspending the side link transmission, and communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0110] The communication manager 715 may also: monitor each resource in a resource set of an unlicensed radio frequency spectrum band associated with the sidelink communication, determine one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access process based on the monitoring, perform channel busy measurement for each of the one or more resources, and communicate with the second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement. The communication manager 715 may be an example of aspects of the communication manager 1010 described herein.

[0111] The communication manager 715 or its subcomponents may be implemented in hardware, in code (software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 715 or its subcomponents may be performed by a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

[0112] The communication manager 715 or its subcomponents can be physically located in a variety of locations, including being distributed so that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 715 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 715 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0113] Transmitter 720 can transmit signals generated by other components of device 705. In some examples, transmitter 720 can be collocated with receiver 710 in a transceiver module. For example, transmitter 720 can be a reference Fig.10 Examples of aspects of the described transceiver 1020. The transmitter 720 may utilize a single antenna or a collection of antennas.

[0114] In some examples, the communication manager 715 may be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver 710 and transmitter 720 may be implemented as analog components (e.g., amplifiers, filters, antennas) coupled with the mobile device modem to enable wireless transmission and reception on one or more frequency bands.

[0115] The communication manager 715 as described herein may be implemented to achieve one or more potential advantages. One embodiment may allow the device 705 to more accurately measure the channel for sidelink communications. The communication manager 715 may use the techniques described herein to determine a sidelink resource set and perform a channel busy measurement to determine whether the sidelink channel can be used for sidelink transmissions.

[0116] Thus, device 705 can more accurately determine congestion on the sidelink channel before sending a sidelink message, which can enable the UE to send sidelink information with higher reliability and, accordingly, communicate on the channel with a greater likelihood of successful communication. In some examples, based on the greater likelihood of successful communication, device 705 can more efficiently power a processor or one or more processing units associated with sending and receiving sidelink communications, which can enable the device to save power and increase battery life.

[0117] Figure 8 A block diagram 800 of a device 805 supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The device 805 may be an example of aspects of the device 705 or UE 115 as described herein. The device 805 may include a receiver 810, a communication manager 815, and a transmitter 850. The device 805 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0118] The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to channel busyness measurements in sidelink communications, etc.). The information may be passed to other components of the device 805. The receiver 810 may be a reference Fig.10 Examples of aspects of the described transceiver 1020. The receiver 810 may utilize a single antenna or a collection of antennas.

[0119] Communications manager 815 may be an example of aspects of communications manager 715 as described herein. Communications manager 815 may include resource component 820, transmit controller 825, measurement component 830, sidelink communications component 835, resource monitoring component 840, and resource determination component 845. Communications manager 815 may be an example of aspects of communications manager 1010 as described herein.

[0120] Resource component 820 can identify a resource set of an unlicensed radio frequency spectrum band that is configured for channel busyness measurement without side link traffic.

[0121] The transmit controller 825 may suspend sidelink transmissions during the identified set of resources.

[0122] Measuring component 830 can perform channel busyness measurements for the set of resources while suspending sidelink transmissions.

[0123] The sidelink communication component 835 can communicate with the second UE via a channel in an unlicensed radio frequency spectrum band based at least in part on a channel busyness measurement.

[0124] The resource monitoring component 840 can monitor each resource in the resource set of the unlicensed radio frequency spectrum band associated with the side link communication.

[0125] Resource determining component 845 can determine one or more resources in the resource set for channel busy measurement, wherein each resource of the one or more resources corresponds to a successful contention-based access procedure based on monitoring.

[0126] Measuring component 830 can perform a channel busyness measurement for each of the one or more resources.

[0127] The sidelink communication component 835 can communicate with the second UE via a channel in an unlicensed radio frequency spectrum band based at least in part on a channel busyness measurement.

[0128] The transmitter 850 can transmit signals generated by other components of the device 805. In some examples, the transmitter 850 can be collocated with the receiver 810 in the transceiver module. For example, the transmitter 850 can be a reference Fig.10 Examples of various aspects of the described transceiver 1020. The transmitter 850 may utilize a single antenna or a collection of antennas.

[0129] Fig. 9 A block diagram 900 of a communication manager 905 supporting channel busy measurements in sidelink communications in accordance with aspects of the present disclosure is shown. The communication manager 905 may be an example of aspects of the communication manager 715, the communication manager 815, or the communication manager 1010 described herein. The communication manager 905 may include a resource component 910, a transmit controller 915, a measurement component 920, a sidelink communication component 925, a channel selection manager 930, a window component 935, a sidelink BWP component 940, a parameter manager 945, a resource monitoring component 950, a resource determination component 955, and an SCI detection component 960. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0130] Resource component 910 can identify a resource set of an unlicensed radio frequency spectrum band that is configured for channel busy measurements without side link traffic. In some examples, resource component 910 can determine a second resource set of an unlicensed radio frequency spectrum band that is configured for channel busy measurements associated with side link traffic.

[0131] The transmit controller 915 may suspend sidelink transmissions during the identified set of resources.

[0132] The measurement component 920 may perform a channel busy measurement for the resource set while suspending the sidelink transmission. In some examples, the measurement component 920 may perform a channel busy measurement for each of the one or more resources. In some examples, the measurement component 920 may measure one or more channel parameters over the measurement window and resource set. In some examples, the measurement component 920 may perform a channel busy measurement for at least one subcarrier excluded from the active bandwidth portion. In some examples, the measurement component 920 may perform a second channel busy measurement for a second resource set.

[0133] In some examples, measuring component 920 can perform a second channel busyness measurement for resources in the second set of resources that do not overlap with the resource set. In some cases, the one or more channel parameters include RSSI, RSRP, RSRQ, SINR, or any combination thereof.

[0134] The sidelink communication component 925 can communicate with the second UE via a channel of an unlicensed radio frequency spectrum band based on a channel busy measurement. In some examples, the sidelink communication component 925 can communicate with the second UE via a channel of an unlicensed radio frequency spectrum band based on a channel busy measurement. In some examples, the sidelink communication component 925 can communicate with the second UE using the communication parameter set.

[0135] The resource monitoring component 950 can monitor each resource in the resource set of the unlicensed radio frequency spectrum band associated with the side link communication.

[0136] Resource determining component 955 can determine one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access procedure based on monitoring. In some examples, resource determining component 955 can perform channel sensing in each resource in the resource set based at least in part on monitoring, wherein one or more resources in the plurality of resources are determined based on successful channel sensing.

[0137] The channel selection manager 930 may select a channel of an unlicensed radio frequency spectrum band for communicating with a second UE based on determining that a congestion level of the channel satisfies a congestion threshold. In some examples, the channel selection manager 930 may select a channel of an unlicensed radio frequency spectrum band for communicating a side link message with a second UE based on determining that a priority of the side link message satisfies a priority threshold. In some examples, the channel selection manager 930 may select a channel of an unlicensed radio frequency spectrum band for communicating with a second UE independently of whether a congestion level of the channel satisfies a congestion threshold.

[0138] In some examples, the channel selection manager 930 can select a channel of an unlicensed radio frequency spectrum band for communicating with the second UE based on the second channel busyness measurement. In some cases, the priority threshold corresponds to a service type of the side link message.

[0139] The window component 935 can determine a measurement window configured for measurement without side link traffic. In some examples, the window component 935 can determine a window of a resource set across an unlicensed radio frequency spectrum band associated with side link communication, wherein a channel busy measurement is performed for each of one or more resources within the window. In some cases, the window corresponds to the number of resource sets. In some cases, the window corresponds to the number of one or more resources.

[0140] Sidelink BWP component 940 may determine an effective bandwidth portion for sidelink communications between the UE and a second UE.

[0141] The parameter manager 945 may determine a communication parameter set for sidelink communication based on the channel busy measurement and the second channel busy measurement. In some examples, the parameter manager 945 may determine a difference between the channel busy measurement and the second channel busy measurement. In some examples, the parameter manager 945 may select a communication parameter set based on the difference. In some cases, the communication parameter set includes an MCS, a transmit power, a number of retransmissions, a number of subchannels, a coding rate, or any combination thereof.

[0142] SCI detection component 960 can detect sidelink control information in each of the one or more resources based on monitoring, wherein one or more resources in the resource set are determined based on detecting the sidelink control information.In some cases, the sidelink control information is associated with a transmitting UE different from the first UE.

[0143] Fig.10 A diagram of a system 1000 including a device 1005 that supports channel busy measurement in sidelink communications according to various aspects of the present disclosure is shown. The device 1005 may be an example of a device 705, a device 805, or a UE 115 as described herein or include components thereof. The device 1005 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 1010, an I / O controller 1015, a transceiver 1020, an antenna 1025, a memory 1030, and a processor 1040. These components may be in electronic communication via one or more buses (e.g., a bus 1045).

[0144] The communication manager 1010 may: identify a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busy measurement without side link traffic, suspend side link transmission during the identified resource set, perform channel busy measurement for the resource set while suspending the side link transmission, and communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0145] The communication manager 1010 may also: monitor each resource in a resource set of an unlicensed radio frequency spectrum band associated with the side link communication, determine one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access process based on the monitoring, perform channel busy measurement for each of the one or more resources, and communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based on the channel busy measurement.

[0146] I / O controller 1015 can manage input and output signals for device 1005. I / O controller 1015 can also manage peripheral devices that are not integrated into device 1005. In some cases, I / O controller 1015 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1015 can utilize a computer such as a , or other known operating systems. In other cases, I / O controller 1015 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 1015 may be implemented as part of a processor. In some cases, a user may interact with device 1005 via I / O controller 1015 or via hardware components controlled by I / O controller 1015.

[0147] As described herein, transceiver 1020 can communicate bidirectionally via one or more antennas, wired or wireless links. For example, transceiver 1020 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 1020 can also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0148] In some cases, device 1005 may include a single antenna 1025, or device 1005 may have more than one antenna 1025 that is capable of simultaneously transmitting or receiving multiple wireless transmissions.

[0149] Memory 1030 may include random access memory (RAM) and read-only memory (ROM). Memory 1030 may store computer-readable, computer-executable code 1035, which includes instructions that, when executed, cause the processor to perform various functions described herein. In some cases, memory 1030 may contain, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0150] Processor 1040 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor 1040 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into processor 1040. Processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1030) to cause device 1005 to perform various functions (e.g., functions or tasks to support channel busy measurement in side link communication).

[0151] The code 1035 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1035 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some cases, the code 1035 may not be directly executable by the processor 1040, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0152] Fig.11 A flow chart illustrating a method 1100 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The operations of the method 1100 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1100 may be implemented by reference to Figures 7 to 10 The communication manager described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0153] At 1105, the UE may identify a resource set of an unlicensed radio frequency spectrum band that is configured for channel busyness measurement without side link traffic. The operations of 1105 may be performed according to the methods described herein. In some examples, aspects of the operations of 1105 may be performed as described in reference to Figures 7 to 10 The resource components described are executed.

[0154] At 1110, the UE may suspend sidelink transmission during the identified resource set. The operations of 1110 may be performed according to the methods described herein. In some examples, aspects of the operations of 1110 may be performed as described in reference to Figures 7 to 10 The sending controller described is executed.

[0155] At 1115, the UE may perform channel busy measurements for the resource set while suspending sidelink transmission. The operations of 1115 may be performed according to the methods described herein. In some examples, aspects of the operations of 1115 may be described with reference to Figures 7 to 10 The described measurement components are performed.

[0156] At 1120, the UE may communicate with a second UE via a channel in an unlicensed radio frequency spectrum band based on the channel busyness measurement. The operations of 1120 may be performed according to the methods described herein. In some examples, aspects of the operations of 1120 may be performed as described in reference to Figures 7 to 10 The described side link communication component is performed.

[0157] Fig.12 A flow chart illustrating a method 1200 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The operations of the method 1200 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1200 may be implemented by reference to Figures 7 to 10 The communication manager described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0158] At 1205, the UE may identify a resource set of an unlicensed radio frequency spectrum band that is configured for channel busyness measurement without side link traffic. The operations of 1205 may be performed according to the methods described herein. In some examples, aspects of the operations of 1205 may be performed as described in reference to Figures 7 to 10 The resource components described are executed.

[0159] At 1210, the UE may suspend sidelink transmission during the identified resource set. The operations of 1210 may be performed according to the methods described herein. In some examples, aspects of the operations of 1210 may be performed as described in reference to Figures 7 to 10 The sending controller described is executed.

[0160] At 1215, the UE may perform channel busy measurements for the resource set while suspending sidelink transmission. The operations of 1215 may be performed according to the methods described herein. In some examples, aspects of the operations of 1215 may be described with reference to Figures 7 to 10The described measurement components are performed.

[0161] At 1220, the UE may select a channel of an unlicensed radio frequency spectrum band for communicating with a second UE based on determining that the congestion level of the channel satisfies the congestion threshold. The operations of 1220 may be performed according to the methods described herein. In some examples, aspects of the operations of 1220 may be performed as described in reference to Figures 7 to 10 The described channel selection manager is executed.

[0162] At 1225, the UE may communicate with a second UE via a channel in an unlicensed radio frequency spectrum band based on the channel busyness measurement. The operations of 1225 may be performed according to the methods described herein. In some examples, aspects of the operations of 1225 may be performed as described in reference to Figures 7 to 10 The described side link communication component is performed.

[0163] Fig.13 A flow chart illustrating a method 1300 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1300 may be implemented by reference to Figures 7 to 10 The communication manager described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0164] At 1305, the UE may identify a resource set of an unlicensed radio frequency spectrum band that is configured for channel busyness measurement without side link traffic. The operations of 1305 may be performed according to the methods described herein. In some examples, aspects of the operations of 1305 may be performed as described in reference to Figures 7 to 10 The resource components described are executed.

[0165] At 1310, the UE may suspend sidelink transmission during the identified resource set. The operations of 1310 may be performed according to the methods described herein. In some examples, aspects of the operations of 1310 may be performed as described in reference to Figures 7 to 10 The sending controller described is executed.

[0166] At 1315, the UE may perform channel busy measurements for the resource set while suspending sidelink transmission. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be described with reference to Figures 7 to 10 The described measurement components are performed.

[0167] At 1320, the UE may select a channel of an unlicensed radio frequency spectrum band for communicating the side link message with the second UE based on determining that the priority of the side link message satisfies the priority threshold. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be performed as described in reference to Figures 7 to 10 The described channel selection manager is executed.

[0168] At 1325, the UE may communicate with a second UE via a channel in an unlicensed radio frequency spectrum band based on the channel busyness measurement. The operations of 1325 may be performed according to the methods described herein. In some examples, aspects of the operations of 1325 may be performed as described in reference to Figures 7 to 10 The described side link communication component is performed.

[0169] Fig.14 A flow chart illustrating a method 1400 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1400 may be implemented by reference to Figures 7 to 10 The communication manager described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0170] At 1405, the UE may identify a resource set of an unlicensed radio frequency spectrum band that is configured for channel busyness measurement without side link traffic. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed as described in reference to Figures 7 to 10 The resource components described are executed.

[0171] At 1410, the UE may suspend sidelink transmission during the identified resource set. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed as described in reference to Figures 7 to 10 The sending controller described is executed.

[0172] At 1415, the UE may perform channel busy measurements for the resource set while suspending sidelink transmission. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be described with reference to Figures 7 to 10 The described measurement components are performed.

[0173] At 1420, the UE may determine a second resource set of an unlicensed radio frequency spectrum band that is configured for channel busyness measurement that may be associated with the sidelink service. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed as described in reference to Figures 7 to 10 The resource components described are executed.

[0174] At 1425, the UE may perform a second channel busy measurement for the second resource set. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be described with reference to Figures 7 to 10 The described measurement components are performed.

[0175] At 1430, the UE may select a channel of an unlicensed radio frequency spectrum band for communicating with a second UE based on the second channel busyness measurement. The operations of 1430 may be performed according to the methods described herein. In some examples, aspects of the operations of 1430 may be performed as described in reference to Figures 7 to 10 The described channel selection manager is executed.

[0176] At 1435, the UE may communicate with a second UE via a channel in an unlicensed radio frequency spectrum band based on the channel busyness measurement. The operations of 1435 may be performed according to the methods described herein. In some examples, aspects of the operations of 1435 may be performed as described in reference to Figures 7 to 10 The described side link communication component is performed.

[0177] Fig.15 A flow chart illustrating a method 1500 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The operations of the method 1500 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1500 may be implemented by reference to Figures 7 to 10 The communication manager described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0178] At 1505, the UE may monitor each resource in a resource set of an unlicensed radio frequency spectrum band associated with the sidelink communication. The operations of 1505 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1505 may be performed as described in reference to Figures 7 to 10 The described resource monitoring component is performed.

[0179] At 1510, the UE may determine one or more resources in a resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access procedure based on monitoring. The operations of 1510 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1510 may be performed as described in reference to Figures 7 to 10 The described resources determine the components to be executed.

[0180] At 1515, the UE may perform channel busyness measurements for each of the one or more resources. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be described with reference to Figures 7 to 10 The described measurement components are performed.

[0181] At 1520, the UE may communicate with a second UE via a channel in an unlicensed radio frequency spectrum band based on the channel busyness measurement. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed as described in reference to Figures 7 to 10 The described side link communication component is performed.

[0182] Fig.16 A flow chart illustrating a method 1600 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by reference to Figures 7 to 10 The communication manager described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0183] At 1605, the UE may monitor each resource in a resource set of an unlicensed radio frequency spectrum band associated with the sidelink communication. The operations of 1605 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1605 may be performed as described in reference to Figures 7 to 10 The described resource monitoring component is performed.

[0184] At 1610, the UE may detect sidelink control information in each of the one or more resources based on monitoring, wherein one or more resources in the resource set are determined based on detecting the sidelink control information. The operations of 1610 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1610 may be performed as described in reference to Figures 7 to 10 The described SCI detection components are performed.

[0185] At 1615, the UE may determine one or more resources in the resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access procedure based on monitoring. The operations of 1615 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1615 may be performed as described in reference to Figures 7 to 10 The described resources determine the components to be executed.

[0186] At 1620, the UE may perform channel busyness measurements for each of the one or more resources. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be described with reference to Figures 7 to 10 The described measurement components are performed.

[0187] At 1625, the UE may communicate with a second UE via a channel in an unlicensed radio frequency spectrum band based on the channel busyness measurement. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed as described in reference to Figures 7 to 10 The described side link communication component is performed.

[0188] Fig.17 A flow chart illustrating a method 1700 for supporting channel busy measurement in sidelink communications according to aspects of the present disclosure is shown. The operations of the method 1700 may be implemented by the UE 115 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by reference to Figures 7 to 10 The communication manager described herein performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described herein. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described herein.

[0189] At 1705, the UE may monitor each resource in a resource set of an unlicensed radio frequency spectrum band associated with the sidelink communication. The operations of 1705 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1705 may be performed as described in reference to Figures 7 to 10 The described resource monitoring component is performed.

[0190] At 1710, the UE may determine one or more resources in a resource set for channel busy measurement, wherein each of the one or more resources corresponds to a successful contention-based access procedure based on monitoring. The operations of 1710 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1710 may be performed as described in reference to Figures 7 to 10 The described resources determine the components to be executed.

[0191] At 1715, the UE may determine a window of a set of resources spanning an unlicensed radio frequency spectrum band associated with the sidelink communication, wherein a channel busyness measurement is performed for each of one or more resources within the window. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed as described with reference to Figures 7 to 10 The described window component is executed.

[0192] At 1720, the UE may perform channel busyness measurements for each of the one or more resources. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be described with reference to Figures 7 to 10 The described measurement components are performed.

[0193] At 1725, the UE may communicate with a second UE via a channel in an unlicensed radio frequency spectrum band based on the channel busyness measurement. The operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be performed as described in reference to Figures 7 to 10 The described side link communication component is performed.

[0194] It should be noted that the methods described herein describe possible implementations, and that operations and steps may be rearranged or otherwise modified, and that other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0195] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and the terminology of LTE, LTE-A, LTE-A Pro, or NR may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0196] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the specification may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0197] The various illustrative logic blocks, components described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, DSP, ASIC, CPU, FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but alternatively, the processor may be any processor, controller, microcontroller or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration).

[0198] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or sent via a computer-readable medium as one or more instructions or codes. Other examples and implementations are within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0199] Computer-readable media include both non-transitory computer storage media and communication media, and the communication media include any media that is conducive to transferring a computer program from one place to another.Non-transitory storage media can be any available media that can be accessed by a general or special computer.By way of example and not limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage devices, or can be used to carry or store desired program code components in the form of instructions or data structures, and can be accessed by a general or special computer or a general or special processor.Any other non-transitory medium.In addition, any connection is appropriately referred to as computer-readable media.For example, if the software is sent from a website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technology (such as infrared, radio and microwave), coaxial cable, fiber optic cable, twisted pair, DSL or wireless technology (such as infrared, radio and microwave) can be included in the definition of computer-readable media. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, where disks usually reproduce data magnetically, while optical discs reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0200] As used herein, including in the claims, "or" as used in a list of items (e.g., a list of items beginning with a phrase such as "at least one of..." or "one or more of...") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C refers to A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Moreover, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0201] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number to distinguish between the similar components. If only the first reference number is used in the specification, the description applies to any similar components having the same first reference number, regardless of the second reference number or other subsequent reference numbers.

[0202] The description set forth herein in conjunction with the accompanying drawings describes exemplary configurations and does not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration," rather than "preferred" or "superior to other examples." For the purpose of providing an understanding of the described techniques, the detailed description includes specific details. However, these techniques may be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the examples.

[0203] The description herein is provided to enable one of ordinary skill in the art to implement or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the examples and designs described herein, but should be given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a first user equipment UE, comprising: Identifying a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busyness measurement without side link traffic; suspending sidelink transmission during the identified set of resources; performing a channel busy measurement for the resource set while suspending sidelink transmission; and Communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based at least in part on the channel busyness measurement.

2. The method according to claim 1, further comprising: The channel of the unlicensed radio frequency spectrum band for communicating with the second UE is selected based at least in part on determining that a congestion level of the channel satisfies a congestion threshold.

3. The method according to claim 1, further comprising: The channel of the unlicensed radio frequency spectrum band for communicating the sidelink message with the second UE is selected based at least in part on determining that the priority of the sidelink message satisfies a priority threshold.

4. The method according to claim 3, further comprising: The channel of the unlicensed radio frequency spectrum band for communicating with the second UE is selected independent of whether the congestion level of the channel satisfies a congestion threshold.

5. The method of claim 3, wherein the priority threshold corresponds to a service type of the sidelink message.

6. The method of claim 1, wherein performing the channel busy measurement comprises: determining a measurement window configured for measurements without sidelink traffic; as well as One or more channel parameters are measured over the measurement window and the resource set.

7. The method of claim 6, wherein the one or more channel parameters include a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal to interference plus noise ratio (SINR), or any combination thereof.

8. The method according to claim 1, further comprising: determining an effective bandwidth portion for sidelink communications between the UE and the second UE; as well as The channel busyness measurement is performed on at least one subcarrier excluded from the effective bandwidth portion.

9. The method according to claim 1, further comprising: Determining a second resource set of the unlicensed radio frequency spectrum band, the second resource set being configured for channel busy measurements associated with sidelink traffic; performing a second channel busy measurement for the second resource set; as well as The channel of the unlicensed radio frequency spectrum band for communicating with the second UE is selected based at least in part on the second channel busyness measurement.

10. The method of claim 9, wherein performing the second channel busy measurement comprises: The second channel busyness measurement is performed on resources in the second resource set that do not overlap with the resource set.

11. A method for wireless communication at a first user equipment UE, comprising: monitoring each of a plurality of resources of an unlicensed radio frequency spectrum band associated with sidelink communications; performing a channel busy measurement for each of one or more resources used for channel busy measurement, the one or more resources belonging to the plurality of resources, wherein each of the one or more resources corresponds to a successful contention-based access procedure based at least in part on the monitoring; as well as Communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based at least in part on the channel busyness measurement.

12. The method according to claim 11, further comprising: Sidelink control information in each of the one or more resources is detected based at least in part on the monitoring, wherein the one or more resources of the plurality of resources are determined based at least in part on detecting the sidelink control information.

13. The method of claim 12, wherein the sidelink control information is associated with a transmitting UE different from the first UE.

14. The method according to claim 11, further comprising: Determine a window of the multiple resources spanning the unlicensed radio frequency spectrum band associated with sidelink communications, wherein the channel busyness measurement is performed for each of the one or more resources within the window.

15. An apparatus for performing wireless communication at a first user equipment UE, comprising: processor, a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: Identifying a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busyness measurement without side link traffic; suspending sidelink transmission during the identified set of resources; performing a channel busy measurement for the resource set while suspending sidelink transmission; and Communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based at least in part on the channel busyness measurement.

16. The device of claim 15, wherein the instructions are further executable by the processor to cause the device to: The channel of the unlicensed radio frequency spectrum band for communicating with the second UE is selected based at least in part on determining that a congestion level of the channel satisfies a congestion threshold.

17. The device of claim 15, wherein the instructions are further executable by the processor to cause the device to: The channel of the unlicensed radio frequency spectrum band for communicating the sidelink message with the second UE is selected based at least in part on determining that the priority of the sidelink message satisfies a priority threshold.

18. The device of claim 17, wherein the instructions are further executable by the processor to cause the device to: The channel of the unlicensed radio frequency spectrum band for communicating with the second UE is selected independent of whether the congestion level of the channel satisfies a congestion threshold.

19. The apparatus of claim 17, wherein the priority threshold corresponds to a service type of the sidelink message.

20. The device of claim 15, wherein the instructions for performing the channel busy measurement are executable by the processor to cause the device to: determining a measurement window configured for measurements without sidelink traffic; and One or more channel parameters are measured over the measurement window and the resource set.

21. The apparatus of claim 20, wherein the one or more channel parameters comprise a received signal strength indicator (RSSI), a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal to interference plus noise ratio (SINR), or any combination thereof.

22. The device of claim 15, wherein the instructions are further executable by the processor to cause the device to: determining an effective bandwidth portion for sidelink communications between the UE and the second UE; and The channel busyness measurement is performed on at least one subcarrier excluded from the effective bandwidth portion.

23. The device of claim 15, wherein the instructions are further executable by the processor to cause the device to: Determining a second resource set of the unlicensed radio frequency spectrum band, the second resource set being configured for channel busy measurements associated with sidelink traffic; performing a second channel busy measurement for the second resource set; as well as The channel of the unlicensed radio frequency spectrum band for communicating with the second UE is selected based at least in part on the second channel busyness measurement.

24. The apparatus of claim 23, wherein the instructions for performing the second channel busy measurement are executable by the processor to cause the apparatus to: The second channel busyness measurement is performed on resources in the second resource set that do not overlap with the resource set.

25. The device of claim 23, wherein the instructions are further executable by the processor to cause the device to: determining a set of communications parameters for sidelink communications based at least in part on the channel busy measurement and the second channel busy measurement; and Communicate with the second UE using the communication parameter set.

26. The apparatus of claim 25, wherein the instructions for determining the set of communication parameters are executable by the processor to cause the apparatus to: determining a difference between the channel busy measurement and the second channel busy measurement; and The set of communications parameters is selected based at least in part on the difference.

27. The apparatus of claim 25, wherein the set of communication parameters comprises a modulation and coding scheme (MCS), a transmit power, a number of retransmissions, a number of subchannels, a coding rate, or any combination thereof.

28. An apparatus for performing wireless communication at a first user equipment UE, comprising: processor, a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: monitoring each of a plurality of resources of an unlicensed radio frequency spectrum band associated with sidelink communications; performing a channel busy measurement for each of one or more resources used for channel busy measurement, the one or more resources belonging to the plurality of resources, wherein each of the one or more resources corresponds to a successful contention-based access procedure based at least in part on the monitoring; as well as Communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based at least in part on the channel busyness measurement.

29. The device of claim 28, wherein the instructions are further executable by the processor to cause the device to: Sidelink control information in each of the one or more resources is detected based at least in part on the monitoring, wherein the one or more resources of the plurality of resources are determined based at least in part on detecting the sidelink control information.

30. The apparatus of claim 29, wherein the sidelink control information is associated with a transmitting UE different from the first UE.

31. The device of claim 28, wherein the instructions are further executable by the processor to cause the device to: Determine a window of the multiple resources spanning the unlicensed radio frequency spectrum band associated with sidelink communications, wherein the channel busyness measurement is performed for each of the one or more resources within the window.

32. The apparatus of claim 31, wherein the window corresponds to a quantity of the plurality of resources.

33. The apparatus of claim 31, wherein the window corresponds to a quantity of the one or more resources.

34. The device of claim 28, wherein the instructions are further executable by the processor to cause the device to: Channel sensing is performed in each of the plurality of resources based at least in part on the monitoring, wherein the one or more resources of the plurality of resources are determined based at least in part on successful channel sensing.

35. An apparatus for wireless communication at a first user equipment UE, comprising: means for identifying a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busyness measurement without side link traffic; means for suspending sidelink transmission during the identified set of resources; means for performing channel busy measurement for the resource set while suspending sidelink transmission; as well as Means for communicating with a second UE via a channel in the unlicensed radio frequency spectrum band based at least in part on the channel busyness measurement.

36. A non-transitory computer-readable storage medium having stored thereon instructions for wireless communication at a first user equipment (UE), the instructions being executed by a processor to: Identifying a resource set of an unlicensed radio frequency spectrum band, the resource set being configured for channel busyness measurement without side link traffic; suspending sidelink transmission during the identified set of resources; performing a channel busy measurement for the resource set while suspending sidelink transmission; as well as Communicate with a second UE via a channel of the unlicensed radio frequency spectrum band based at least in part on the channel busyness measurement.

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