Feedback for sidechain transmission

Abstract

Methods, systems, and devices for wireless communications are described. A receiver user equipment (UE) may communicate with a transmitter UE in a sidelink channel to report a congestion index to the transmitter UE and / or additional transmitter UEs, wherein the (multiple) transmitter UEs may then adjust one or more sidelink operating parameters based on the reported congestion index. In some cases, the transmitter UE may report the congestion index to an upper layer, other transmitter UEs, an application layer, or a combination thereof. The transmitter UE 115 and / or the application layer may then adjust one or more sidelink transmission operating parameters based on the reported congestion index. For example, the transmitter UE and / or the application layer may adjust a threshold to reduce the number of retransmissions and reduce congestion.

Description

[0001] Cross-references

[0002] This patent application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 909,149, filed on October 1, 2019, by Nguyen et al., entitled “Feedback for Sidelink Transmission”; and U.S. Patent Application Serial No. 17 / 036,983, filed on September 29, 2020, by Nguyen et al., entitled “Feedback for Sidelink Transmission”; each of which is assigned to the assignee of this patent application. Technical Field

[0003] The following relates generally to wireless communications, and more particularly to feedback of sidelink transmissions. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, etc. These systems may be able to 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 that 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 multiple access (DFT-S-OFDM). A wireless multiple access communication system may include multiple base stations or network access nodes, each of which simultaneously supports communication with multiple communication devices, which may be referred to as user equipment (UE).

[0005] In some wireless communication systems, multiple UEs may communicate with each other via a sidelink channel. For example, the sidelink channel may include device-to-device (D2D) communication, vehicle-to-vehicle (V2V) communication, vehicle-to-everything (V2X) communication, etc. Additionally, the UEs may share resources in the sidelink channel, such that as more UEs enter the wireless communication system and attempt to use the sidelink channel, contention for the shared resources may increase and may affect one or more sidelink transmissions between the UEs. When the wireless communication system becomes congested (e.g., when more UEs compete for shared resources), effective techniques are needed to ensure the quality of service (QoS) of communications (e.g., sidelink communications) on the sidelink channel. Summary of the invention

[0006] The described technology relates to improved methods, systems, devices and apparatuses for supporting feedback of sidelink transmissions. In general, the described technology provides a first user equipment (UE) (e.g., a sending UE) to send a sidelink data transmission to a second UE (e.g., a receiving UE) on a sidelink channel, and then the second UE sends a sidelink channel congestion indicator (e.g., a congestion index) in a feedback message after receiving the sidelink data transmission. Therefore, the first UE can then adapt one or more sidelink parameters (e.g., sidelink transmission operation parameters, sidelink operation parameters, etc.) based on the sidelink channel congestion indicator. For example, the first UE can adjust the feedback distance (e.g., the distance between UEs expecting or sending feedback, reference signal received power (RSRP) measurement, etc.) or additional sidelink operation parameters based on a sidelink channel congestion indicator indicating whether the packet error rate (PER) and / or bit rate is high or low at the current feedback distance.

[0007] In some cases, the first UE may receive multiple feedback messages and sidelink channel congestion indicators from various receiving UEs, and may aggregate (e.g., average) the multiple feedback messages into a single congestion index. Subsequently, the first UE may report a single congestion index to an upper layer, broadcast the aggregated multiple feedback messages (e.g., aggregated reports) to other sending UEs, report the aggregated multiple feedback messages to the application layer, or a combination thereof. Additionally, the second UE (e.g., and other receiving UEs) may periodically send feedback messages with a sidelink channel congestion indicator, wherein the periodicity for sending the feedback message is configured by the first UE, derived from signaling, event-driven, configured by the network (e.g., via network signaling, pre-configured in the UE, etc.), or a combination thereof. In some cases, the first UE and the second UE may communicate based on a connectionless multicast configuration (e.g., the first UE is unaware of the second UE and other receiving UEs before sending the sidelink data transmission via multicast transmission), wherein the sidelink data transmission is a connectionless sidelink multicast data transmission.

[0008] A method for wireless communication by a first UE is described. The method may include: sending a sidelink data transmission to a second UE via a sidelink channel; receiving a sidelink channel congestion indicator (e.g., a congestion index) from the second UE via the sidelink channel; and communicating with the second UE via the sidelink channel according to a sidelink operating parameter (e.g., a sidelink parameter, a sidelink transmission operating parameter, etc.) adjusted based on the sidelink channel congestion indicator.

[0009] An apparatus for wireless communication by 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 are executable by the processor to cause the apparatus to: send a sidelink data transmission to a second UE via a sidelink channel; receive a sidelink channel congestion indicator from the second UE via the sidelink channel; and communicate with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based on the sidelink channel congestion indicator.

[0010] Another apparatus for wireless communication by a first UE is described. The apparatus may include components for: sending a sidelink data transmission to a second UE via a sidelink channel; receiving a sidelink channel congestion indicator from the second UE via the sidelink channel; and communicating with the second UE via the sidelink channel based on a sidelink operating parameter adjusted based on the sidelink channel congestion indicator.

[0011] A non-transitory computer-readable medium is described that stores code for wireless communication by a first UE. The code may include instructions executed by a processor to: send a sidelink data transmission to a second UE via a sidelink channel; receive a sidelink channel congestion indicator from the second UE via the sidelink channel; and communicate with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based on the sidelink channel congestion indicator.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with a second UE via a sidelink channel may include operations, features, components, or instructions for communicating with the second UE via the sidelink channel based on a sidelink operating parameter, which sidelink operating parameter may be one or more of the following: a number of retransmissions parameter, a feedback distance parameter, a distance parameter, a control exclusion distance parameter, an RSRP parameter, a control exclusion RSRP parameter, or any combination thereof.

[0013] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with a second UE via a sidelink channel may include operations, features, components, or instructions for retransmitting a sidelink data transmission to the second UE via the sidelink channel based on a sidelink operating parameter.

[0014] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a congestion indicator configuration to a second UE via a sidelink channel, wherein the sidelink channel congestion indicator may be based on the congestion indicator configuration.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a congestion indicator configuration may include operations, features, components, or instructions for sending a congestion indicator configuration to indicate a periodicity at which the second UE may report a sidelink channel congestion indicator.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a congestion indicator configuration may include operations, features, components, or instructions for sending a congestion indicator configuration to indicate an event after detection of which the second UE may report a sidelink channel congestion indicator.

[0017] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the sidelink channel congestion indicator may be received according to a congestion indicator configuration. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the first UE may be configured by a network device having a congestion indicator configuration, or the first UE may be pre-configured with a congestion indicator configuration.

[0018] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a sidelink data transmission may include operations, features, components, or instructions for sending a sidelink data transmission including geolocation data for a first UE and one or more packet indexes of one or more packets included within the sidelink data transmission.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a feedback message for a sidelink data transmission including geolocation data of a second UE and an indication of one or more packets received within a time interval, wherein communication with the second UE via a sidelink channel may be based on the feedback message.

[0020] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for adjusting a sidelink operating parameter by adjusting a feedback distance threshold based on a sidelink channel congestion indicator, wherein communication via the sidelink channel may satisfy the adjusted feedback distance threshold based on a distance between the first UE and the second UE.

[0021] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for adjusting sidelink operating parameters by adjusting one or more of a feedback distance threshold, a control exclusion range threshold, an input data rate, or any combination thereof based on a sidelink channel congestion indicator, wherein communication with a second UE via the sidelink channel may be based on the adjustment.

[0022] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a feedback message from a second UE via a sidelink channel, the feedback message providing an indication of one or more packets received within a time interval, and operations, features, components, or instructions for generating a corrected indication of one or more packets received within the time interval based on processing the feedback message to determine that the second UE did not receive one or more additional packets, wherein communication with the second UE via the sidelink channel may be based on the corrected feedback message.

[0023] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a first feedback message for a sidelink data transmission from a second UE and at least a second feedback message from at least a third UE via a sidelink channel, determining aggregate feedback based on the first feedback message and the at least second feedback message, and adjusting a sidelink operating parameter based on the aggregate feedback, wherein communication with the second UE via the sidelink channel may be based on the adjustment.

[0024] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a first feedback message for a sidelink data transmission from a second UE and at least a second feedback message from at least a third UE via a sidelink channel, determining an aggregated multicast PER, an aggregated multicast bitrate, or both at a set of different distances based on the first feedback message and the at least second feedback message, and adjusting a sidelink operating parameter based on the aggregated multicast PER, the aggregated multicast bitrate, or both, wherein communication with the second UE via the sidelink channel may be based on the adjustment.

[0025] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving, from a second UE, a combined feedback packet including a first feedback message corresponding to a sidelink data transmission and a second feedback message for at least one additional wireless device, and parsing the first feedback message from the combined feedback packet, wherein communication with the second UE via the sidelink channel may be based on the first feedback message.

[0026] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the combined feedback packet includes a receiver-side congestion index for at least one quality of service class.

[0027] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a feedback message of sidelink data transmission from a second UE via a sidelink channel, the feedback message including one or more of: an identifier of the first UE, a PER, a bit rate, a feedback cycle start, an end of a feedback cycle, a packet identifier of a first packet received within the cycle, a packet identifier of a last packet received within the cycle, positioning data of the second UE, orientation data of the second UE, speed data of the second UE, a distance between the first UE and the second UE, or any combination thereof, wherein communication with the second UE via the sidelink channel may be based on the feedback message.

[0028] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for a medium access control (MAC) control element (CE) to receive a feedback message including a sidelink data transmission, wherein communication with a second UE via a sidelink channel may be based on the feedback message.

[0029] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving an uplink data transmission including a feedback message for the sidelink data transmission from a second UE, wherein communication with the second UE via the sidelink channel may be based on the feedback message.

[0030] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a feedback message for sidelink data transmission from a second UE, the feedback message including a sidelink channel congestion indicator, wherein communication with the second UE via the sidelink channel may be based on the feedback message.

[0031] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a sidelink data transmission may include operations, features, components, or instructions for sending the sidelink data transmission as a connectionless sidelink multicast data transmission.

[0032] A method for wireless communication by a first UE is described. The method may include: monitoring a sidelink channel for sidelink data transmission from a second UE; sending a sidelink channel congestion indicator to the second UE via the sidelink channel; and communicating with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based on the sidelink channel congestion indicator.

[0033] An apparatus for wireless communication by 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 are executable by the processor to cause the apparatus to: monitor a sidelink channel for sidelink data transmission from a second UE; send a sidelink channel congestion indicator to the second UE via the sidelink channel; and communicate with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based on the sidelink channel congestion indicator.

[0034] Another apparatus for wireless communication by a first UE is described. The apparatus may include components for: monitoring a sidelink channel for sidelink data transmission from a second UE; sending a sidelink channel congestion indicator to the second UE via the sidelink channel; and communicating with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based on the sidelink channel congestion indicator.

[0035] A non-transitory computer-readable medium is described that stores code for wireless communication by a first UE. The code may include instructions executable by a processor to: monitor a sidelink channel for sidelink data transmission from a second UE; send a sidelink channel congestion indicator to the second UE via the sidelink channel; and communicate with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based on the sidelink channel congestion indicator.

[0036] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with a second UE via a sidelink channel may include operations, features, components, or instructions for communicating with the second UE via the sidelink channel based on a sidelink operating parameter, which sidelink operating parameter may be one or more of the following: a number of retransmissions parameter, a feedback distance parameter, a distance parameter, a control exclusion distance parameter, an RSRP parameter, a control exclusion RSRP parameter, or any combination thereof.

[0037] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, communicating with a second UE via a sidelink channel may include operations, features, components, or instructions for monitoring retransmissions of sidelink data transmissions from the second UE via the sidelink channel based on sidelink operating parameters.

[0038] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for receiving a congestion indicator configuration from a second UE via a sidelink channel, wherein a sidelink channel congestion indicator may be sent to the second UE based on the congestion indicator configuration.

[0039] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving a congestion indicator configuration may include operations, features, components, or instructions for receiving a congestion indicator configuration indicating a periodicity at which the first UE may report a sidelink channel congestion indicator.

[0040] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending a congestion indicator configuration may include operations, features, components, or instructions for receiving a congestion indicator configuration indicating an event after detection of which the first UE may report a sidelink channel congestion indicator.

[0041] In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the sidelink channel congestion indicator may be received according to a congestion indicator configuration. In some examples of the methods, apparatuses, and non-transitory computer-readable media described herein, the first UE may be configured by a network device having a congestion indicator configuration, or the first UE may be pre-configured with a congestion indicator configuration.

[0042] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, monitoring a sidelink channel for a sidelink data transmission may include operations, features, components, or instructions for receiving a sidelink data transmission including geolocation data for a first UE and one or more packet indices for one or more packets included within the sidelink data transmission.

[0043] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a feedback message for a sidelink data transmission including geolocation data of the first UE and an indication of one or more packets received within a time interval, wherein communication with a second UE via a sidelink channel may be based on the feedback message.

[0044] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for adjusting a sidelink operating parameter by adjusting a feedback distance threshold based on a sidelink channel congestion indicator, and sending a feedback message that negatively acknowledges sidelink data transmission to trigger a retransmission of the sidelink data transmission by the second UE based on a distance between the first UE and the second UE satisfying the adjusted feedback distance threshold.

[0045] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for adjusting sidelink operating parameters by adjusting one or more of a feedback distance threshold, a control exclusion range threshold, an input data rate, or any combination thereof based on a sidelink channel congestion indicator, wherein communication with a second UE via the sidelink channel may be based on the adjustment.

[0046] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a combined feedback package to a second UE, the combined feedback package including a first feedback message corresponding to a sidelink data transmission and at least a second feedback message for at least one additional wireless device.

[0047] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the combined feedback packet includes a receiver-side congestion index for at least one quality of service class.

[0048] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a feedback message of sidelink data transmission to a second UE via a sidelink channel, the feedback message including one or more of: an identifier of the second UE, a PER, a bit rate, a feedback cycle start, an end of a feedback cycle, a packet identifier of a first packet received within the cycle, a packet identifier of a last packet received within the cycle, positioning data of the first UE, orientation data of the first UE, speed data of the first UE, a distance between the first UE and the second UE, or any combination thereof, wherein communication with the second UE via the sidelink channel may be based on the feedback message.

[0049] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a MAC CE including a feedback message for sidelink data transmission, wherein communication with a second UE via a sidelink channel may be based on the feedback message.

[0050] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending an uplink data transmission including a feedback message for the sidelink data transmission to a second UE, wherein communication with the second UE via a sidelink channel may be based on the feedback message.

[0051] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for sending a feedback message for sidelink data transmission to a second UE, the feedback message including a sidelink channel congestion indicator, wherein communication with the second UE via the sidelink channel may be based on the feedback message.

[0052] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the sidelink data transmission may be a connectionless sidelink multicast data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1An example of a wireless communication system supporting feedback for sidelink transmissions according to aspects of the present disclosure is shown.

[0054] Figure 2 An example of a wireless communication system according to aspects of the present disclosure is shown.

[0055] Figure 3 An example of a process flow according to aspects of the present disclosure is shown.

[0056] Figure 4 and Figure 5 A block diagram of a device according to aspects of the present disclosure is shown.

[0057] Figure 6 A block diagram of a communications manager in accordance with aspects of the present disclosure is shown.

[0058] Figure 7 A diagram of a system including devices according to aspects of the present disclosure is shown.

[0059] Figures 8 to 14 A flow chart illustrating a method according to aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0060] The described techniques provide for a receiver user equipment (UE) communicating with a transmitter UE in a sidelink channel to report a congestion indicator (e.g., a congestion index, a sidelink channel congestion indicator, etc.) to the transmitter UE and / or additional transmitter UEs, where the (multiple) transmitter UEs can then adjust one or more sidelink operating parameters (e.g., sidelink transmit operating parameters) based on the reported congestion indicators.

[0061] In a sidelink wireless communication system, wireless devices can share the same set of resources for sidelink communication. Therefore, for different use cases in the sidelink wireless communication system (e.g., device-to-device (D2D) communication, vehicle-to-vehicle (V2V) communication, vehicle-to-everything (V2X) communication, etc.), quality of service (QoS) can be ensured through resource exclusion and / or distance-based exclusion. In resource exclusion, if the distance between UEs is below a resource exclusion threshold (Thresh RE ), the measured signal quality (e.g., reference signal received power (RSRP)) is higher than the resource exclusion threshold (Thresh RE ), etc., the UE can avoid using the same resources reserved by another UE. In addition, it is allowed to send unsuccessful packets and the distance / measured signal quality between UEs is below the feedback threshold (Thresh FB) to retransmit. Conventional systems may rely on a determination by a transmitter (e.g., a transmitting UE) as to whether a sidelink channel is congested. Such a determination by the transmitter may raise fairness issues because a first transmitter may determine that the sidelink channel is congested and stop transmitting, while a second transmitter nearby may determine that the sidelink channel is not congested shortly after the first transmitter stops transmitting. Additionally or alternatively, this determination may lead to inaccuracy issues, where a transmitter may determine that the channel is congested but a receiver may still receive sidelink communications, or a transmitter may determine that the channel is not congested but a receiver cannot receive sidelink communications.

[0062] As described herein, to mitigate these issues, a receiver UE may report a congestion indicator (e.g., a congestion index) to one or more transmitter UEs. Subsequently, in some cases, the transmitter UE may adjust a distance-based feedback threshold (Thresh FB , or different sidelink operating parameters) to manage congestion of the sidelink channel. For example, the transmitter UE may use the adjusted threshold to determine whether to retransmit to a specific receiver that did not successfully receive a previous transmission. If the distance between the transmitter UE and the receiver UE is less than the distance-based feedback threshold, the transmitter UE may retransmit. Additionally or alternatively, if the distance between the transmitter UE and the receiver UE exceeds the distance-based feedback threshold, the receiver UE may be too far away, and the transmitter UE may skip retransmitting the previous transmission because it is still unlikely that the receiver UE will successfully receive the retransmission. In some cases, the transmitter UE may configure the receiver UE with the frequency and time of reporting the congestion indicator.

[0063] Various aspects of the present disclosure are initially described in the context of wireless communication systems. Additionally, various aspects of the present disclosure are illustrated by additional wireless communication systems and process flows. Various aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow charts related to feedback of sidelink transmissions.

[0064] Figure 1 An example of a wireless communication system 100 supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The wireless communication system 100 includes a base station 105, a UE 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 cases, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

[0065] The base station 105 may communicate wirelessly with the UE 115 via one or more base station antennas. The base station 105 described herein may include or may be referred to by those skilled in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, 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 terminology. The wireless communication system 100 may include different types of base stations 105 (e.g., macro cell base stations or small cell base stations). The UE 115 described herein may be able to communicate with various types of base stations 105 and network devices, including macro eNBs, small cell eNBs, gNBs, relay base stations, etc.

[0066] Each base station 105 may be associated with a particular geographic coverage area 110 in which it supports communications with various UEs 115. Each base station 105 may provide communications coverage for a corresponding geographic coverage area 110 via a communication link 125, and the communication link 125 between the base station 105 and the UE 115 may utilize one or more carriers. The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. Downlink transmissions may also be referred to as forward link transmissions, and uplink transmissions may also be referred to as reverse link transmissions.

[0067] The geographic coverage area 110 of the base station 105 can be divided into sectors that constitute a portion of the geographic coverage area 110, and each sector can be associated with a cell. For example, each base station 105 can provide communication coverage for a macro cell, a small cell, a hotspot, or other types of cells, or various combinations thereof. In some examples, the base station 105 can be mobile and thus provide communication coverage for a mobile geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, and overlapping geographic coverage areas 110 associated with different technologies can be supported by the same base station 105 or different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous LTE / LTE-A / LTE-A Pro or NR network in which different types of base stations 105 provide coverage for various geographic coverage areas 110.

[0068] The term "cell" refers to a logical communication entity used to communicate with a base station 105 (e.g., via a carrier), and it can be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID)) used to distinguish between adjacent cells operating via the same or different carriers. In some examples, a carrier can support multiple cells, and different cells can be configured according to different protocol types that can provide access to different types of devices (e.g., machine type communication (MTC), narrowband Internet of Things (NB-IoT), enhanced mobile broadband (eMBB), or other). In some cases, the term "cell" may refer to a portion of a geographic coverage area 110 (e.g., a sector) on which the logical entity operates.

[0069] UE 115 can be dispersed throughout the wireless communication system 100, and each UE 115 can be fixed or mobile. UE 115 can also 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 "device" can also be referred to as a unit, a station, a terminal, or a client. UE 115 can be 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 can also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, etc., which can be implemented in various items such as appliances, vehicles, meters, etc.

[0070] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that are integrated with sensors or meters to measure or capture information and relay the information to a central server or application that may utilize the information or present the information to a person interacting with the program or application. Some UEs 115 may be designed to collect information or enable automated behavior of machines. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based business charging.

[0071] Some UEs 115 may be configured to employ a reduced power consumption mode of operation, such as half-duplex communication (e.g., a mode that supports one-way communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed at a reduced peak rate. Other power saving techniques for UE 115 include entering an energy-saving "deep sleep" mode when not engaged in active communications, or operating over a limited bandwidth (e.g., in accordance with narrowband communications). In some cases, UE 115 may be designed to support critical functions (e.g., mission-critical functions), and the wireless communication system 100 may be configured to provide ultra-reliable communications for these functions.

[0072] In some cases, UE 115 can also communicate directly with other UE 115 (e.g., using peer-to-peer (P2P) or D2D protocols). One or more UEs in a group of UEs 115 utilizing D2D communication may be within the geographic coverage area 110 of the base station 105. Other UEs 115 in the group may be outside the geographic coverage area 110 of the base station 105, or may not be able to receive transmissions from the base station 105 for other reasons. In some cases, 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 cases, the base station 105 facilitates resource scheduling for D2D communication. In other cases, D2D communication is performed between UEs 115 without the involvement of the base station 105.

[0073] The base stations 105 may communicate with the core network 130 and with each other. For example, the base stations 105 may interface with the core network 130 via a backhaul link 132 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130) via a backhaul link 134 (e.g., via X2, Xn, or other interfaces).

[0074] 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), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME may manage non-access stratum (e.g., control plane) functions such as mobility, authentication, and bearer management for UEs 115 served by base stations 105 associated with the EPC. User IP packets may be transmitted through the S-GW, which itself may be connected to the P-GW. The P-GW may provide IP address allocation and other functions. The P-GW may be connected to the IP services of the network operator. The operator's IP services may include access to the Internet, (one or more) intranets, IP multimedia subsystems (IMS), or packet switched (PS) streaming services.

[0075] At least some network devices, such as base stations 105, may include subcomponents, such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity may communicate with UE 115 through multiple other access network transport entities, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). In some configurations, the various functions of each access network entity or base station 105 may be distributed across various network devices (e.g., radio heads and access network controllers) or merged into a single network device (e.g., base station 105).

[0076] The wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Generally, the region from 300MHz to 3GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the length of the wavelength ranges from about 1 decimeter to 1 meter. UHF waves may be blocked or redirected by buildings and environmental features. However, the waves can penetrate the structure sufficiently to enable the macrocell to provide services to the UE 115 located indoors. Compared with the transmission of smaller frequencies and longer waves using the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300MHz, the transmission of UHF waves can be associated with smaller antennas and shorter ranges (e.g., less than 100km).

[0077] The wireless communication system 100 may also operate in a Super High Frequency (SHF) region using frequency bands from 3 GHz to 30 GHz (also referred to as centimeter bands). The SHF region includes frequency bands such as the 5 GHz Industrial, Scientific, and Medical (ISM) bands, which may be used appropriately by devices that can tolerate interference from other users.

[0078] The wireless communication system 100 can also operate in the extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz), which is also referred to as the millimeter band. In some examples, the wireless communication system 100 can support millimeter wave (mmW) communications between UE 115 and base station 105, and the EHF antennas of each device can be even smaller and closer than UHF antennas. In some cases, this can promote the use of antenna arrays in UE 115. However, the propagation of EHF transmissions may even be subject to greater atmospheric attenuation and shorter ranges than SHF or UHF transmissions. The technology disclosed herein can be adopted across transmissions using one or more different frequency regions, and the designated use of frequency bands across these frequency regions may differ from country to country or regulatory agency.

[0079] In some cases, the wireless communication system 100 can utilize both licensed radio bands and unlicensed radio bands. For example, the wireless communication system 100 can adopt license assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in unlicensed bands such as the 5GHz ISM band. When operating in an unlicensed radio band, wireless devices such as base stations 105 and UE 115 can adopt a listen-before-talk (LBT) process to ensure that the frequency channel is idle before sending data. In some cases, 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, peer-to-peer transmissions, or a combination of these transmissions. Duplexing in unlicensed spectrum can be based on frequency division duplexing (FDD), time division duplexing (TDD), or a combination of the two.

[0080] In some examples, the base station 105 or the UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. For example, the wireless communication system 100 may use a transmission scheme between a transmitting device (e.g., a base station 105) and a receiving device (e.g., a UE 115), wherein the transmitting device is equipped with multiple antennas and the receiving device is equipped with one or more antennas. MIMO communications may employ multipath signal propagation to improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers, which may be referred to as spatial multiplexing. Multiple signals may be transmitted, for example, by a transmitting device via different antennas or different combinations of antennas. Similarly, multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams. Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are sent to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are sent to multiple devices.

[0081] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam or a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals communicated via antenna elements of an antenna array so that signals propagating in a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements can include the transmitting device or the receiving device applying certain amplitude and phase offsets to the signals carried via each antenna element associated with the device. The adjustments associated with each antenna element can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0082] In one example, the base station 105 may use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 115. For example, some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be sent multiple times by the base station 105 in different directions, which may include signals sent according to different beamforming weight sets associated with different transmission directions. The transmissions in different beam directions may be used to identify the beam direction (e.g., by the base station 105 or a receiving device such as the UE 115) for subsequent transmission and / or reception by the base station 105.

[0083] Some signals, such as data signals associated with a particular receiving device, may be sent by base station 105 in a single beam direction (e.g., a direction associated with a receiving device, such as UE 115). In some examples, a beam direction associated with transmissions along a single beam direction may be determined based at least in part on signals sent in different beam directions. For example, UE 115 may receive one or more of the signals sent by base station 105 in different directions, and UE 115 may report to base station 105 an indication of the signal it received having the highest signal quality or other acceptable signal quality. Although these techniques are described with reference to signals sent by base station 105 in one or more directions, UE 115 may employ similar techniques to send signals multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115), or to send signals in a single direction (e.g., to send data to a receiving device).

[0084] When receiving various signals such as synchronization signals, reference signals, beam selection signals, or other control signals from the base station 105, a receiving device (e.g., UE 115, which may be an example of a millimeter wave receiving device) may try multiple receive beams. For example, the receiving device may try multiple receive directions by receiving via different antenna subarrays, processing received signals according to different antenna subarrays, receiving according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, or processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as "listening" according to different receive beams or receive directions. In some examples, the receiving device may receive along a single beam direction using a single receive beam (e.g., when receiving a data signal). A single receive beam may be aligned on a beam direction determined at least in part based on listening to different receive beam directions (e.g., a beam direction with the highest signal strength, highest signal-to-noise ratio, or other acceptable signal quality determined at least in part based on listening to multiple beam directions).

[0085] In some cases, the antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays that may support MIMO operations, or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be collocated at an antenna assembly such as an antenna tower. In some cases, the antennas or antenna arrays associated with a base station 105 may be located at different geographic locations. A base station 105 may have an antenna array with multiple rows and columns of antenna ports that the base station 105 may use to support beamforming for communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations.

[0086] In some cases, the wireless communication system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication at the bearer or packet data convergence protocol (PDCP) layer may be IP-based. The radio link control (RLC) layer may perform packet segmentation and reassembly to communicate on a logical channel. The medium access control (MAC) layer may perform priority processing and multiplexing of logical channels to transmission channels. The MAC layer may also use a hybrid automatic repeat request (HARQ) to provide retransmission at the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer may provide the establishment, configuration and maintenance of an RRC connection (which supports radio bearers for user plane data) between a UE 115 and a base station 105 or a core network 130. At the physical layer, a transport channel may be mapped to a physical channel.

[0087] In some cases, UE 115 and base station 105 can support retransmission of data to increase the possibility of successfully receiving data. HARQ feedback is a technology that increases the possibility of correctly receiving data through communication link 125. HARQ can include a combination of error detection (e.g., using cyclic redundancy check (CRC)), forward error correction (FEC) and retransmission (e.g., automatic repeat request (ARQ)). HARQ can improve the throughput at the MAC layer under poor radio conditions (e.g., signal-to-noise ratio conditions). In some cases, a wireless device can support simultaneous slot HARQ feedback, where the device can provide HARQ feedback for data received in the previous symbol in the slot in a specific time slot. In other cases, the device can provide HARQ feedback in subsequent time slots or according to some other time interval.

[0088] The time interval in LTE or NR can be expressed as a multiple of the basic time unit. For example, the time interval can be referred to as T s=1 / 30,720,000 second sampling period. The time intervals of the communication resources can be organized according to radio frames (each radio frame has a duration of 10 milliseconds (ms)), where the frame period can be represented as T f =307,200Ts. A radio frame may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include 10 subframes numbered from 0 to 9, and each subframe may have a duration of 1 ms. A subframe may be further divided into 2 slots, each slot having a duration of 0.5 ms, and each slot may contain 6 or 7 modulation symbol periods (e.g., depending on the length of the cyclic prefix before each symbol period). In addition to the cyclic prefix, each symbol period may contain 2048 sampling periods. In some cases, a subframe may be the minimum scheduling unit of the wireless communication system 100 and may be referred to as a transmit time interval (TTI). In other cases, the minimum scheduling unit of the wireless communication system 100 may be shorter than a subframe or may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI) or in a selected component carrier using sTTI).

[0089] In some wireless communication systems, a time slot may also be divided into a plurality of mini-slots containing one or more symbols. In some instances, a mini-slot or a symbol of a mini-slot may be the minimum unit of scheduling. The duration of each symbol may vary depending on, for example, the subcarrier spacing or the operating frequency band. In addition, some wireless communication systems may implement time slot aggregation, in which a plurality of time slots or mini-slots are aggregated together and used for communication between UE 115 and base station 105.

[0090] The term "carrier" refers to a collection of radio spectrum resources that have a defined physical layer structure for supporting communications on the communication link 125. For example, a carrier of the communication link 125 may include a portion of a radio frequency spectrum band that operates according to a physical layer channel for a given radio access technology. Each physical layer channel may carry user data, control information, or other signaling. A carrier may be associated with a predefined frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel raster for discovery by a UE 115. A carrier may be a downlink or uplink (e.g., in FDD mode), or may be configured to carry downlink and uplink communications (e.g., in TDD mode). In some examples, a signal waveform transmitted on a carrier may be composed of multiple subcarriers (e.g., using a multi-carrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)).

[0091] The organization structure of the carrier can be different for different radio access technologies (e.g., LTE, LTE-A, LTE-A Pro, NR). For example, communications on a carrier can be organized based on TTIs or time slots, where each TTI or time slot can include user data and control information or signaling to support decoding of the user data. The carrier can also include dedicated acquisition signaling (e.g., synchronization signals or system information, etc.) and control signaling to coordinate carrier operations. In some examples (e.g., in a carrier aggregation configuration), the carrier can also have acquisition signaling or control signaling to coordinate the operation of other carriers.

[0092] Physical channels may be multiplexed on a carrier according to various techniques. For example, a physical control channel and a physical data channel may be multiplexed on a downlink carrier using a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. In some examples, the control information sent in the physical control channel may be distributed in a cascaded manner between different control regions (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

[0093] A carrier may be associated with a particular bandwidth of radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of a plurality of predetermined bandwidths of a carrier for a particular radio access technology (e.g., 1.4 MHz, 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 40 MHz, or 80 MHz). In some examples, each served UE 115 may be configured to operate on part or all of the carrier bandwidth. In other examples, some UEs 115 may be configured to operate using a narrowband protocol type associated with a predefined portion or range (e.g., a set of subcarriers or RBs) within a carrier (e.g., an "in-band" deployment of a narrowband protocol type).

[0094] In a system using MCM technology, a resource element may consist of 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). Therefore, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 may be. In a MIMO system, wireless communication resources may refer to a combination of radio spectrum resources, time resources, and space resources (e.g., space layers), and the use of multiple space layers may also increase the data rate for communicating with UE 115.

[0095] A device (e.g., base station 105 or UE 115) of wireless communication system 100 may have a hardware configuration that supports communication on a specific carrier bandwidth, or may be configured to support communication on one carrier bandwidth in a set of carrier bandwidths. In some examples, wireless communication system 100 may include base station 105 and / or UE 115 that supports simultaneous communication via carriers associated with more than one different carrier bandwidths.

[0096] The wireless communication system 100 may support communication with the UE 115 on multiple cells or carriers, a feature that may be referred to as 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 FDD and TDD component carriers.

[0097] In some cases, the wireless communication system 100 can utilize an enhanced component carrier (eCC). An eCC can be characterized by one or more features including a wider carrier or frequency channel bandwidth, a shorter symbol duration, a shorter TTI duration, or a modified control channel configuration. In some cases, an eCC can be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have suboptimal or non-ideal backhaul links). An eCC can also be configured for use in an unlicensed spectrum or a shared spectrum (e.g., where more than one operator is allowed to use the spectrum). An eCC characterized by a wide carrier bandwidth can include one or more segments that can be used by a UE 115 that cannot monitor the entire carrier bandwidth or is otherwise configured to use a limited carrier bandwidth (e.g., to save power).

[0098] In some cases, an eCC may utilize a different symbol duration than other component carriers, which may include using a reduced symbol duration compared to the symbol duration of other component carriers. A shorter symbol duration may be associated with an increased spacing between adjacent subcarriers. A device such as a UE 115 or a base station 105 utilizing an eCC may transmit a wideband signal (e.g., according to a frequency channel or carrier bandwidth of 20 Mhz, 40 Mhz, 60 Mhz, 80 MHz, etc.) with a reduced symbol duration (e.g., 16.67 microseconds). A TTI in an eCC may consist of one or more symbol periods. In some cases, the TTI duration (i.e., the number of symbol periods in a TTI) may be variable.

[0099] The wireless communication system 100 may be an NR system that may utilize any combination of licensed, shared, and unlicensed spectrum bands, etc. The flexibility of eCC symbol duration and subcarrier spacing may allow the use of eCC across multiple spectrums. In some examples, NR shared spectrum may increase spectrum utilization and spectrum efficiency, specifically through dynamic vertical (e.g., across frequency domain) and horizontal (e.g., across time domain) resource sharing.

[0100] In sidelink communication, multiple UEs 115 can communicate with each other via sidelink channels. Sidelink channels can include time and frequency resources reserved in the network for transmissions between UEs 115. For example, base station 105 can configure a set of time and frequency resources that UE 115 can use for sidelink transmissions to / from other UEs 115. In some cases, sidelink channels can support different types of communications between UEs 115, such as D2D, P2P, V2V, V2X, etc.

[0101] For different sidelink communication types, QoS can be ensured through a resource exclusion process and / or a distance-based feedback process. For example, for the resource exclusion process, if the distance between UEs 115 (e.g., how far apart UEs 115 are physically from each other) and / or the signal power measurement between UEs 115 (e.g., RSRP measurement) is below a threshold value (Thresh RE ), the UE 115 may avoid using the same resources reserved by another UE 115 (e.g., resources reserved for sidelink retransmissions). Additionally or alternatively, for a distance-based feedback process, if the UE 115 cannot receive packets (e.g., sidelink transmissions) from another UE 115, and the distance / RSRP between the UEs 115 is below a threshold value (Thresh FB ), then based on the distance / RSRP between UE 115 being below a threshold, a retransmission of the packet may be sent to UE 115.

[0102] Typically, for sidelink communications, when the system becomes congested (e.g., a large number of UEs 115 contend for the same set of resources configured for sidelink communications), the transmitter UE 115 may throttle the bit rate used to send the sidelink transmission (e.g., reduce the speed of the sidelink transmission, which may reduce the number of resources used, the number of retransmissions sent, etc.). Additionally or alternatively, the receiver UE 115 may reduce the packet reception rate (e.g., reduce the number of packets that need to be received in order to indicate whether the transmission was successfully received). For example, with a higher packet reception rate (e.g., a higher number of packets need to be received to indicate that the transmission was successfully received), a higher number of feedback messages may be sent by the receiver UE 115 and / or a higher number of retransmissions may be sent from the transmitter UE 115, thereby increasing congestion. In some cases, the UE 115 may also reduce the range of packet error rate (PER) expectations (e.g., how many packets can be unsuccessfully received or decoded while still determining that the transmission was successfully received).

[0103] These conventional systems may then rely on a determination by a transmitter (e.g., a transmitting UE 115) as to whether the sidelink channel is congested. In some cases, the transmitter UE may collect congestion information (e.g., as defined for dedicated short range communications (DSRC), LTE V2X, WiFi, etc.) using a constant bit rate (CBR) method (e.g., as defined for dedicated short range communications (DSRC), LTE V2X, WiFi, etc.). Additionally or alternatively, the transmitter UE may determine congestion of a channel (e.g., a sidelink channel) in the network using an observed amount of reserved resources, an amount of packets dropped due to no available resources, a number of transmissions achieved per packet, or a combination thereof. Such a determination by a transmitter may raise fairness issues because a first transmitter may determine that the sidelink channel is congested and stop transmitting, while a nearby second transmitter may determine that the sidelink channel is not congested shortly after the first transmitter stops transmitting. Additionally, in some of the methods described above by the transmitter UE to determine channel congestion, when seeing the busyness (e.g., congestion) of the channel (e.g., time-frequency resources), it may not distinguish the priority of the transmitted data (e.g., sidelink data) or the QoS of the data.

[0104] The wireless communication system 100 may support efficient techniques for collecting network congestion indices (e.g., sidelink channel congestion indicators) and reporting the network congestion indices to the application layer, where the application layer decides to throttle the bit rate and / or reduce QoS expectations. For example, a new type of congestion index (e.g., sidelink channel congestion index) that can be collected at the receiver UE 115 may be defined, and the receiver UE 115 may then report the congestion index to the transmitter UE 115. Subsequently, the transmitter UE 115 may aggregate congestion index reports from multiple receiver UEs 115 (e.g., received via multicast or broadcast transmission). In some cases, the transmitter UE 115 may report the aggregated congestion index report to the upper layer, broadcast the aggregated congestion index report to other transmitter UEs 115, report the received aggregated congestion index report to the application layer, or a combination thereof. Then, the sender UE 115 and / or the application layer may adjust one or more sidelink transmission operation parameters (e.g., sidelink operation parameters) based on the aggregate congestion index report (e.g., increase or decrease the feedback distance / range to reduce or increase the number of retransmission attempts of the negative acknowledgement (NACK) feedback message). For example, the sender UE 115 and / or the application layer may adjust the threshold (e.g., Threshold 100). FB , or adjusting different sidelink transmission operating parameters) to reduce the amount of feedback and the number of retransmissions sent by the receiver UE 115, thereby reducing congestion in the system.

[0105] Figure 2 An example of a wireless communication system 200 supporting feedback of sidelink transmissions 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 one or more UEs 115 and base stations 105-a, which can be as described above with reference to Figure 1 The example of the corresponding UE 115 and base station 105 described. In some cases, the wireless communication system 200 can support sidelink communication between UE 115. For example, UE 115 may include one or more receiver UE 205 and one or more transmitter UE 210. As shown in the figure, receiver UE 205 may include UE 115-a, UE 115-b and UE 115-c, and transmitter UE 210 may include UE 115-d, UE115-e and UE 115-f. Therefore, receiver UE 205 and transmitter UE 210 can communicate by configuring a sidelink channel for sidelink transmission. For example, base station 105-a can configure a time-frequency resource set (e.g., a sidelink channel) that UE 115 can use for sidelink transmission to / from other UE 115.

[0106] In some cases, the wireless communication system 200 may also support a connectionless multicast configuration for sidelink communication between UEs 115. For example, the connectionless multicast configuration may include no setup before the UE 115 sends / receives the sidelink transmission. The receiver UE 115 may be aware of some or all of the nearby transmitter UEs 210, and may monitor sidelink packets from some or all of the nearby transmitter UEs 210. In some cases, the receiver UE 205 may identify a time window for monitoring / receiving sidelink packets, and remain awake during the time window to monitor and / or receive sidelink packets from the transmitter UE 115. Additionally, the receiver UE 115 may have connections with multiple transmitter UEs 115. Similarly, the transmitter UE 115 may have connections with multiple receiver UEs 115. However, the transmitter UE 115 may not know which receiver UE 115 is in the wireless communication system 200 before sending the sidelink packet (e.g., a priori). In some cases, the receiver UE 115 may determine interest in the sidelink packet based on a distance between the receiver UE 115 and the transmitter UE 115 that sent the sidelink packet.

[0107] In some cases, the transmitter UE 115 may send a feedback configuration 215 to one or more receiver UEs 115 (e.g., based on a connectionless multicast configuration). For example, the feedback configuration 215 may instruct the receiver UE 205 to send periodic feedback (e.g., acknowledgment (ACK) / NACK feedback). The periodicity of the feedback (e.g., when the receiver UE 205 is to send feedback) may be configured or pre-configured. For example, the periodicity may be configured by the network (e.g., base station 105-a), via an Internet connection, etc., or may even be configured by the transmitter UE 115 (e.g., in the feedback configuration 215). In some cases, the receiver UE 205 may pre-configure the periodicity based on factory settings programmed into the UE 115 at the time of manufacture (e.g., when communicating in an unlicensed band (such as for sidelink communication), periodic feedback will be sent). Additionally or alternatively, the periodicity may be implicitly derived by the receiver UE 205 from the 5G QoS indicator (5QI) and / or the feedback distance signaled. Additionally or alternatively, the periodicity may be event driven.For example, the receiver UE 205 may send a feedback message when the measured QoS is below a configured limit (eg, the receiver UE misses more than 10% of the sidelink packets sent by the sender UE 115).

[0108] When sending periodic feedback, the receiver UE 205 may include a transmitter identification of the transmitter UE 115 (e.g., indicating which transmitter UE 115 the feedback is for), a PER of the side chain packets received from the transmitter UE 115 (e.g., how many side chain packets were not successfully received / decoded), and a bit rate of the received side chain packets. Additionally, the periodic feedback may include the start of a feedback period in which the feedback is sent (e.g., the start of the time window in which feedback is given for the side chain packets received during the time window), the end of the feedback period, an identification of the first side chain packet received in the feedback period (e.g., indicating the earliest packet received within the time window), and an identification of the last side chain packet received in the feedback period (e.g., indicating the latest packet received within the time window). In some cases, the information about the side chain packets (e.g., PER, bit rate, side chain packet identification, etc.) and the information about the feedback period may be referred to as a congestion index 220 (e.g., a side chain channel congestion indicator). For example, based on the congestion index 220 and the feedback period with information about the sidelink packets, the transmitter UE 115 can determine the congestion level in the system. In some cases, a high PER and bit rate can indicate that the receiver UE 115 did not successfully receive a large number of sidelink packets, for example due to high congestion in the system.

[0109] Additionally, the periodic feedback may also include information about the receiver UE 115, such as a location (e.g., geolocation) of the receiver UE 115, an orientation of the receiver UE 115, a speed of the receiver UE 115, an identity of the receiver UE 115, and a distance between the receiver UE 115 and the transmitter UE 115. The information about the receiver UE 115 may enable the transmitter UE 115 to determine whether the receiver UE 115 is moving closer to or farther from the transmitter UE 115.

[0110] In some cases, the receiver UE 115 may send periodic feedback information (e.g., including congestion index 220, sidelink channel congestion indicator, etc.) in a MAC control element (CE). For example, if the scope requirement for periodic feedback is the same or similar to the scope requirement for data, the receiver UE 115 may piggyback the periodic feedback with the data in the MAC CE. Additionally or alternatively, feedback to different transmitter UEs 115 may be combined in one broadcast feedback packet. Therefore, the receiver UE 115 may still associate the transmitter identity with each periodic feedback in the combined broadcast feedback packet, so that the transmitter UE 115 may search for its own identity in the packet to determine whether any periodic feedback in the combined broadcast feedback packet is for the transmitter UE 115, and thus may decode and receive the corresponding periodic feedback. With the combined broadcast feedback packet, information about the receiver UE 115 (e.g., the location, orientation, speed, etc. of the receiver UE 115) may be shared with all transmitter UEs 210 before the combined broadcast feedback packet is transmitted to save payload size. In some cases, the combined broadcast feedback packet may also include a common transmission side congestion index (e.g., per QoS category) so that the information can be crowdsourced to obtain a fair distributed congestion control mechanism. The common transmission side congestion index may be an example of a sidelink channel congestion indicator as described herein. Additionally or alternatively, periodic feedback to different transmitter UEs 115 may also be sent to each transmitter UE 115 individually, for example, in a unicast manner. For example, the receiver UE 115 may send periodic feedback in a unicast manner based on the importance or priority of the transmitter UE 115 and the sidelink transmission sent by the transmitter UE 115 (e.g., a higher priority sidelink transmission may require unicast feedback).

[0111] Subsequently, in some cases, after receiving periodic feedback (e.g., including the congestion index 220) from the receiver UE 115, the transmitter UE 115 may correct the received feedback information. For example, the transmitter UE 115 may learn which and how many side chain packets were sent during a feedback period (e.g., a time window, a time interval, etc.) indicated by the receiver UE 115. Thus, if the transmitter UE 115 determines that more side chain packets were sent during the feedback period than indicated by the identification of the first and last side chain packets received by the receiver UE 115 (e.g., as indicated in the periodic feedback), the transmitter UE 115 may infer that control of those lost side chain packets was lost, and may adjust the PER and bit rate reported in the periodic feedback accordingly.

[0112] As an example, the receiver UE 115 may report that the first received sidechain packet in the feedback cycle has an identifier of '4' and the last received sidechain packet in the feedback cycle has an identifier of '20'. The transmitter UE 115 may then determine that the first sidechain packet was sent with an identifier of '2' and the last sidechain packet was sent with an identifier of '21' in the feedback cycle based on the start and end of the feedback cycle reported from the receiver UE 115. Therefore, the transmitter UE 115 may determine that the receiver UE 115 missed at least three packets (e.g., more packets between the first and last received sidechain packets may also be missed), and the reported PER and bit rate of the received sidechain packets reported by the receiver UE 115 may be adjusted to reflect these additional missed sidechain packets.

[0113] In some cases, the transmitter UE 115 may aggregate feedback information from multiple receiver UEs 115 to obtain multicast PER and bit rate at different distances. For example, the transmitter UE 115 may obtain an average value (e.g., average PER and bit rate) of all received feedback information from the receiver UE 205. Additionally or alternatively, the transmitter UE 115 may aggregate all feedback information from multiple receiver UEs 115 differently (e.g., weighted average, median, etc.) based on the type of sidelink data sent to each receiver UE 115, the priority of the sidelink data, etc. After aggregating the feedback information, the transmitter UE 115 may report the aggregate feedback to an upper layer (e.g., RRC layer), broadcast the aggregate feedback to other transmitter UEs 115, report the aggregate feedback to an application layer, or a combination thereof. For example, the transmitter UE 115 may send an aggregate congestion index 225 (e.g., an aggregated sidelink channel congestion indicator) to the base station 105-a (e.g., an upper layer, an application layer, etc.). The aggregate feedback may include an aggregate congestion index 225 based on aggregate feedback indicating (eg, via reported / adjusted PER, bit rate, etc.) the level of congestion in the system.

[0114] The transmitter UE 115 and / or the application layer may then adjust one or more sidelink transmission operating parameters (e.g., sidelink operating parameters) based on the aggregate feedback and the aggregate congestion index 225. As an example, the aggregate feedback and the aggregate congestion index 225 may indicate that the receiving UE 115 is experiencing an average error rate (e.g., average PER) of 20% (e.g., 20% of the sidelink packets are received / decoded in error), while the target / threshold error rate is 10%. Therefore, the transmitter UE 115 and / or the application layer (e.g., base station 105-a) may determine that the high error rate is caused by a high congestion level. Therefore, the transmitter UE 115 and / or the application layer may reduce the feedback distance (e.g., Threshold PER) based on the estimated PER and bit rate being high at the current feedback distance.FB , feedback distance threshold, feedback range, etc.), thereby reducing the number of retransmissions sent and alleviating congestion. In some cases, the transmitter UE 115 and / or the application layer may adjust other sidelink transmission operating parameters (e.g., other sidelink transmission operating parameters) based on the identified high congestion (such as the number of retransmissions that can be attempted, the expected communication range, the control exclusion distance / RSRP, the input data rate, etc.). For example, the adjusted sidelink transmission operating parameters may increase the range of acceptable sidelink transmissions so that the receiver UE 115 sends an ACK with periodic feedback (e.g., fewer retransmissions sent as a result of a NACK). If the sidelink transmission still falls within the range of the adjusted sidelink transmission operating parameters (e.g., higher feedback distance, higher expected communication range, etc.), the receiver UE 115 may still send a NACK and the periodic feedback may still indicate a high congestion level, causing the transmitter UE 115 and / or the application layer to perform further mitigation (e.g., further increase the feedback distance threshold Threshold). FB , expected communication range, adjusting one or more side chain transmission operating parameters, etc.).

[0115] Additionally or alternatively, in another example, the aggregate feedback and aggregate congestion index 225 may indicate that the receiving UE 115 is experiencing an average error rate (e.g., average PER) of 5% (e.g., 5% of the sidelink packets are received / decoded in error), while the target / threshold error rate is still 10%. Therefore, the transmitter UE 115 and / or the application layer (e.g., base station 105-a) may determine that the low error rate is caused by the feedback distance being too conservative (e.g., the threshold is too high), and may increase the feedback distance (e.g., Threshold 106) based on the estimated PER and bit rate being low at the current feedback distance. FB , or adjusting another sidelink operating parameter), thereby increasing the requirements (e.g., more aggressive requirements) for determining whether the sidelink transmission is successfully received and decoded. For example, the receiver UE 115 can send NACK feedback more frequently, resulting in sending a higher quality sidelink transmission to enable the receiver UE 115 to send an ACK.

[0116] Figure 3 An example of a process flow 300 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. In some examples, the process flow 300 may implement aspects of the wireless communication systems 100 and / or 200. The process flow 300 may include UE 115-g and UE 115-h, which may be as described above with reference to Figure 1 and Figure 2An example of a UE 115 is described. As described herein, a UE 115-g and a UE 115-h may communicate on a sidelink channel, where the UE 115-g may be referred to as a transmitter UE 115-g and the UE 115-h may be referred to as a receiver UE 115-h (e.g., the transmitter UE 115-g sends a sidelink data transmission to the receiver UE 115-h).

[0117] In the following description of the process flow 300, the operations between the UE 115-g and the UE 115-h may be sent in a different order than the exemplary order shown, or the operations performed by the UE 115-g and the UE 115-h may be performed in a different order or at a different time. Certain operations may also be omitted from the process flow 300, or other operations may be added to the process flow 300. It should be understood that although the UE 115-g and the UE 115-h are shown to perform several operations of the process flow 300, any wireless device may perform the operations shown.

[0118] At 305, UE 115-g may send a congestion indicator configuration to UE 115-h via a sidelink channel, wherein a sidelink channel congestion indicator (e.g., a congestion index, a sidelink congestion index, etc.) is based on the congestion indicator configuration. In some cases, UE 115-g may send the congestion indicator configuration to indicate the periodicity of UE 115-h reporting the sidelink channel congestion indicator. Additionally or alternatively, UE 115-g may send the congestion indicator configuration to indicate an event after which UE 115-h will report the sidelink channel congestion indicator. In some cases, the congestion indicator configuration may be configured by a network device (e.g., base station 105, network, etc.), pre-configured for UE 115-g and UE 115-h (e.g., pre-coded within UE 115 when manufactured), or a combination thereof.

[0119] At 310, UE 115-g may send a sidelink data transmission to UE 115-h via a sidelink channel. In some cases, the sidelink channel may include time and frequency resources reserved in the network for transmissions between UEs 115. For example, base station 105 may configure a set of time-frequency resources that UEs 115-g and 115-h may use for sidelink transmissions to / from other UEs 115. Additionally, UE 115-g may send a sidelink data transmission that includes geolocation data (e.g., positioning information) of UE 115-g and one or more packet indexes (e.g., packet identifiers) of one or more packets included within the sidelink data transmission. In some cases, UE 115-g may send the sidelink data transmission as a connectionless sidelink multicast data transmission.

[0120] Thus, UE 115-h may monitor the sidelink channel for a sidelink data transmission from UE 115-g. In some cases, UE 115-h may receive a sidelink data transmission that includes geolocation data for UE 115-g and one or more packet indices for one or more packets included in the sidelink data transmission.

[0121] At 315 , UE 115 - h may send a sidelink channel congestion indicator to UE 115 - g via the sidelink channel.

[0122] At 320, UE 115-h may send a feedback message for the sidelink data transmission, the feedback message including geolocation data of UE 115-h and an indication of one or more packets received in the time interval. In some cases, UE 115-g may receive a feedback message for the sidelink data transmission from UE 115-h via a measurement channel, the feedback message including one or more of: an identifier of UE 115-g (e.g., a transmitter UE identity), PER, bit rate, feedback period start, feedback period end, a packet identifier of a first packet received in the feedback period, a packet identifier of a last packet received in the feedback period, positioning data of UE 115-h, orientation data of UE 115-h, speed data of UE 115-h, a distance between UE 115-g and UE 115-h, or any combination thereof.

[0123] In some cases, UE 115-g may receive a MAC CE including a feedback message for the sidelink data transmission. Additionally or alternatively, UE 115-g may receive an uplink data transmission including a feedback message for the sidelink data transmission from UE 115-g. In some cases, UE 115-g may receive a feedback message for the sidelink data transmission from UE 115-h, the feedback message including a sidelink channel congestion indicator.

[0124] At 325, UE 115-g may receive a first feedback message for a sidelink data transmission from UE 115-h and at least a second feedback message from an additional UE 115 (e.g., an additional receiver UE 115, more than one additional UE 115, etc.) via the sidelink channel, and may determine an aggregate feedback based on the first feedback message and the at least second feedback message. In some cases, UE 115-g may adjust a sidelink operating parameter based on the aggregate feedback.

[0125] Additionally or alternatively, UE 115-g may receive a first feedback message for a sidelink data transmission from UE 115-h and at least a second feedback message from an additional UE 115 (e.g., from a plurality of additional UEs 115) via a sidelink channel, and may determine an aggregate multicast PER, an aggregate multicast bit rate, or both at a plurality of different distances based on the first feedback message and the at least second feedback message. In some cases, UE 115-g may adjust sidelink operating parameters based on the aggregate multicast PER, the aggregate multicast bit rate, or both.

[0126] In some cases, UE 115-g may receive, from UE 115-h, a combined feedback packet including a first feedback message corresponding to a sidelink data transmission and at least a second feedback message for at least one additional wireless device (e.g., for an additional transmitter UE 115). Accordingly, UE 115-g may parse the first feedback message from the combined feedback packet, wherein the combined feedback packet includes a receiver-side congestion index for at least one QoS class.

[0127] Additionally, in some cases, UE 115-h may send a combined feedback packet to UE 115-g that includes a first feedback message corresponding to the sidelink data transmission and at least a second feedback message for at least one additional wireless device, wherein the combined feedback packet includes a receiver-side congestion index for at least one QoS category.

[0128] At 330, UE 115-g may adjust a sidelink operating parameter (e.g., a sidelink transmission operating parameter) by adjusting a feedback distance threshold based on the sidelink channel congestion indicator, wherein communication via the sidelink channel is based on a distance between UE 115-g and UE 115-h satisfying the adjusted feedback distance threshold. Additionally or alternatively, UE 115-g may adjust the sidelink operating parameter by adjusting one or more of a feedback distance threshold (e.g., an expected communication range threshold), a control exclusion range threshold, an input data rate, or any combination thereof based on the sidelink channel congestion indicator.

[0129] In some cases, UE 115-g may receive a feedback message from UE 115-h via the sidelink channel that provides an indication of one or more packets received during the time interval (e.g., or a NACK for the sidelink data transmission). Additionally, UE 115-g may generate a corrected indication of one or more packets received during the time interval (e.g., a corrected feedback message) based on processing the feedback message to determine that UE 115-h did not receive the one or more additional packets.

[0130] At 335, UE 1115-g may communicate with UE 115-h via the sidelink channel based on a sidelink operating parameter (e.g., a sidelink transmission operating parameter) adjusted based on the sidelink channel congestion indicator. In some cases, UE 115-g may communicate with UE 115-h via the sidelink channel based on the sidelink operating parameter, which is one or more of the following: a number of retransmissions parameter, a feedback distance parameter, a distance parameter, a control exclusion distance parameter, an RSRP parameter, a control exclusion RSRP parameter, or any combination thereof. Additionally or alternatively, UE 115-g may retransmit the sidelink data transmission to UE 115-h via the sidelink channel based on the sidelink operating parameter. In some cases, UE 115-h may monitor retransmissions of sidelink data transmissions sent from UE 115-g via the sidelink channel based on the sidelink operating parameter.

[0131] Additionally, UE 115-h may adjust sidelink operating parameters by adjusting a feedback distance threshold based on a sidelink channel congestion indicator, and may send a feedback message negatively acknowledging sidelink data transmission based on the distance between UE 115-g and UE 115-h satisfying the adjusted feedback distance threshold to trigger a retransmission of the sidelink data transmission performed by UE 115-g.

[0132] In some cases, UE 115-h may adjust sidelink operating parameters by adjusting one or more of a feedback distance threshold, a control exclusion range threshold, an input data rate, or any combination thereof based on a sidelink channel congestion indicator, wherein the communication with UE 115-g via the sidelink channel is based on the adjustment.

[0133] Figure 4 A block diagram 400 of a device 405 supporting feedback for sidelink transmission according to aspects of the present disclosure is shown. The device 405 may be an example of aspects of the UE 115 as described herein. The device 405 may include a receiver 410, a communication manager 415, and a transmitter 420. The device 405 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0134] Receiver 410 may receive information associated with various information channels (e.g., control channels, data channels, and information related to feedback of sidelink transmissions, etc.), such as packets, user data, or control information. The information may be passed to other components of device 405. Receiver 410 may be a reference Figure 7 Examples of aspects of the described transceiver 720. The receiver 410 may utilize a single antenna or a collection of antennas.

[0135] The communication manager 415 may send a sidelink data transmission to the second UE via the sidelink channel. In some cases, the communication manager 415 may receive a sidelink channel congestion indicator (e.g., a congestion index, a sidelink congestion index, etc.) from the second UE via the sidelink channel. Thus, the communication manager 415 may communicate with the second UE via the sidelink channel according to a sidelink operating parameter (e.g., a sidelink transmission operating parameter) adjusted based on the sidelink channel congestion indicator.

[0136] Additionally or alternatively, the communication manager 415 may monitor the sidelink channel to obtain a sidelink data transmission from the second UE. In some cases, the communication manager 415 may send a sidelink channel congestion indicator to the second UE via the sidelink channel. Therefore, the communication manager 415 may communicate with the second UE via the sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The communication manager 415 may be an example of aspects of the communication manager 710 described herein.

[0137] In some examples, the communication manager 415 can be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver 410 and the transmitter 420 can be implemented as analog components (e.g., amplifiers, filters, antennas) coupled to the mobile device modem to enable wireless transmission and reception on one or more frequency bands.

[0138] The communication manager 415 described herein may be implemented to achieve one or more potential advantages. One implementation may allow the device 405 to indicate and determine a level of congestion in the sidelink communication system via a sidelink channel congestion indicator (e.g., a congestion index) to enable an application layer (e.g., a base station, a scheduler, a network, etc.) to adjust one or more sidelink operating parameters to reduce congestion in the sidelink communication system. Thus, by enabling the application layer to reduce congestion in the sidelink communication system, the communication manager 415 may increase the reliability of the device 405 successfully receiving and decoding a sidelink transmission, or the device 405 more reliably sending a sidelink transmission to a receiver device in the sidelink communication system.

[0139] The communication manager 415 or its subcomponents may be implemented in hardware, in code executed by a processor (e.g., software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 415 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.

[0140] The communication manager 415 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 415 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 415 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.

[0141] Transmitter 420 can transmit signals generated by other components of device 405. In some examples, transmitter 420 can be co-located with receiver 410 in a transceiver module. For example, transmitter 420 can be a reference Figure 7 Examples of aspects of the described transceiver 720. The transmitter 420 may utilize a single antenna or a collection of antennas.

[0142] Figure 5 A block diagram 500 of a device 505 supporting feedback for sidelink transmission according to aspects of the present disclosure is shown. The device 505 may be an example of aspects of the device 405 or UE 115 as described herein. The device 505 may include a receiver 510, a communication manager 515, and a transmitter 545. The device 505 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0143] The receiver 510 may receive information associated with various information channels (e.g., control channels, data channels, and information related to feedback of sidelink transmissions, etc.), such as packets, user data, or control information. The information may be passed to other components of the device 505. The receiver 510 may be a reference Figure 7 Examples of aspects of the described transceiver 720. The receiver 510 may utilize a single antenna or a collection of antennas.

[0144] The communication manager 515 may be an example of aspects of the communication manager 415 described herein. The communication manager 515 may include a sidelink data transmitter 520, a congestion indicator component 525, a sidelink communicator 530, a sidelink channel monitoring component 535, and a congestion indicator 540. The communication manager 515 may be an example of aspects of the communication manager 710 described herein.

[0145] The sidelink data transmitter 520 may send a sidelink data transmission to the second UE via the sidelink channel.

[0146] Congestion indicator component 525 may receive a sidelink channel congestion indicator from the second UE via the sidelink channel.

[0147] The sidelink communicator 530 may communicate with the second UE via the sidelink channel according to the sidelink operating parameters adjusted based on the sidelink channel congestion indicator.

[0148] Sidelink channel monitoring component 535 can monitor the sidelink channel for sidelink data transmissions from the second UE.

[0149] The congestion indicator 540 may send a sidelink channel congestion indicator to the second UE via the sidelink channel.

[0150] Based on the technique for indicating and determining the congestion level in the sidelink communication system, the processor of UE 115 (e.g., as described in reference Figure 7 The control receiver 510, transmitter 545 or transceiver 720) described above can increase the reliability of successfully receiving and decoding the sidelink transmission at the receiver UE. Additionally, the processor can enable the UE 115 to save power by reducing the number of retransmissions sent as a result of the adjusted sidelink operating parameters. For example, the adjusted sidelink operating parameters can increase the reliability that the first sidelink transmission is successful and does not require a retransmission, thereby reducing the power consumption used to prepare and send retransmissions at the UE 115.

[0151] Transmitter 545 can transmit signals generated by other components of device 505. In some examples, transmitter 545 can be co-located with receiver 510 in a transceiver module. For example, transmitter 545 can be a reference Figure 7 Examples of aspects of the described transceiver 720. The transmitter 545 may utilize a single antenna or a collection of antennas.

[0152] Figure 6 A block diagram 600 of a communication manager 605 supporting feedback for sidelink transmissions in accordance with aspects of the present disclosure is shown. The communication manager 605 may be an example of aspects of the communication manager 415, the communication manager 515, or the communication manager 710 described herein. The communication manager 605 may include a sidelink data transmitter 610, a congestion indicator component 615, a sidelink communicator 620, a congestion indicator configuration component 625, a feedback receiver 630, a sidelink parameter adjuster 635, a combined feedback package component 640, a sidelink channel monitoring component 645, a congestion indicator 650, and a feedback transmitter 655. Each of these modules may communicate with each other directly or indirectly (e.g., via one or more buses).

[0153] The sidelink data transmitter 610 may transmit a sidelink data transmission to the second UE via a sidelink channel. In some examples, the sidelink data transmitter 610 may transmit a sidelink data transmission including geolocation data of the first UE and one or more packet indexes of one or more packets included in the sidelink data transmission. Additionally, the sidelink data transmitter 610 may transmit the sidelink data transmission as a connectionless sidelink multicast data transmission.

[0154] The congestion indicator component 615 may receive a sidelink channel congestion indicator from the second UE via the sidelink channel.

[0155] The sidelink communicator 620 may communicate with the second UE via the sidelink channel according to the sidelink operating parameters adjusted based on the sidelink channel congestion indicator. In some examples, the sidelink communicator 620 may communicate with the second UE via the sidelink channel according to the sidelink operating parameters adjusted based on the sidelink channel congestion indicator.

[0156] Additionally or alternatively, the sidechain communicator 620 may communicate with the second UE via the sidechain channel based on a sidechain operating parameter, the sidechain operating parameter being one or more of the following: a number of retransmissions parameter, a feedback distance parameter, a distance parameter, a control exclusion distance parameter, an RSRP parameter, a control exclusion RSRP parameter, or any combination thereof. In some examples, the sidechain communicator 620 may retransmit the sidechain data transmission to the second UE via the sidechain channel based on the sidechain operating parameter. Additionally or alternatively, the sidechain communicator 620 may monitor the retransmission of the sidechain data transmission sent from the second UE via the sidechain channel based on the sidechain operating parameter.

[0157] The sidelink channel monitoring component 645 can monitor the sidelink channel to obtain a sidelink data transmission from the second UE. In some examples, the sidelink channel monitoring component 645 can receive a sidelink data transmission that includes geolocation data of the first UE and one or more packet indexes of one or more packets included in the sidelink data transmission. In some cases, the sidelink data transmission can be sent as a connectionless sidelink multicast data transmission.

[0158] The congestion indicator 650 may send a sidelink channel congestion indicator to the second UE via the sidelink channel.

[0159] The congestion indicator configuration component 625 may send a congestion indicator configuration to the second UE via a sidelink channel, wherein the sidelink channel congestion indicator is based on the congestion indicator configuration. In some examples, the congestion indicator configuration component 625 may send a congestion indicator configuration to indicate the periodicity of the second UE reporting the sidelink channel congestion indicator. Additionally or alternatively, the congestion indicator configuration component 625 may send a congestion indicator configuration to indicate an event after which the second UE will report the sidelink channel congestion indicator. In some cases, the congestion indicator configuration may be configured by a network device (e.g., a base station, a network, etc.), pre-configured for the first UE and the second UE (e.g., pre-coded within the UE when manufactured), or a combination thereof.

[0160] Alternatively, the congestion indicator configuration component 625 may receive a congestion indicator configuration from the second UE via a sidelink channel, wherein the sidelink channel congestion indicator is sent to the second UE based on the congestion indicator configuration. In some examples, the congestion indicator configuration component 625 may receive a periodic congestion indicator configuration indicating that the first UE reports the sidelink channel congestion indicator. Additionally or alternatively, the congestion indicator configuration component 625 may receive a congestion indicator configuration indicating an event after which the first UE will report the sidelink channel congestion indicator. In some cases, the congestion indicator configuration may be configured by a network device (e.g., a base station, a network, etc.), pre-configured for the first UE and the second UE (e.g., pre-coded within the UE when manufactured), or a combination thereof.

[0161] The feedback receiver 630 may receive a feedback message for a sidelink data transmission, the feedback message including geolocation data of the second UE and an indication of one or more packets received in the time interval, wherein the communication with the second UE via the sidelink channel is based on the feedback message. In some examples, the feedback receiver 630 may receive a feedback message including an indication of one or more packets received in the time interval from the second UE via the sidelink channel, and may generate a correction indication of the one or more packets received in the time interval based on processing the feedback message to determine that the second UE did not receive the one or more additional packets, wherein the communication with the second UE via the sidelink channel is based on the corrected feedback message.

[0162] Additionally or alternatively, the feedback receiver 630 may receive a feedback message of the sidelink data transmission from the second UE via the sidelink channel, the feedback message comprising one or more of: an identifier of the first UE, PER, a bit rate, a feedback cycle start, an end of a feedback cycle, a packet identifier of a first packet received within the cycle, a packet identifier of a last packet received within the cycle, positioning data of the second UE, orientation data of the second UE, speed data of the second UE, a distance between the first UE and the second UE, or any combination thereof, wherein communication with the second UE via the sidelink channel is based on the feedback message.

[0163] In some examples, the feedback receiver 630 may receive a MAC CE including a feedback message for sidelink data transmission, wherein the communication with the second UE via the sidelink channel is based on the feedback message. Additionally or alternatively, the feedback receiver 630 may receive an uplink data transmission including a feedback message for sidelink data transmission from the second UE, wherein the communication with the second UE via the sidelink channel is based on the feedback message. In some examples, the feedback receiver 630 may receive a feedback message for sidelink data transmission from the second UE, the feedback message including a sidelink channel congestion indicator, wherein the communication with the second UE via the sidelink channel is based on the feedback message.

[0164] The sidelink parameter adjuster 635 may adjust the sidelink operating parameters by adjusting the feedback distance threshold based on the sidelink channel congestion indicator, wherein the communication via the sidelink channel is based on the distance between the first UE and the second UE satisfying the adjusted feedback distance threshold. Additionally or alternatively, the sidelink parameter adjuster 635 may adjust the sidelink operating parameters by adjusting one or more of the feedback distance threshold, the control exclusion range threshold, the input data rate, or any combination thereof based at least in part on the sidelink channel congestion indicator, wherein the communication with the second UE via the sidelink channel is based on the adjustment.

[0165] In some examples, the sidelink parameter adjuster 635 can receive a first feedback message for a sidelink data transmission from a second UE and at least a second feedback message from at least a third UE via a sidelink channel, can determine aggregate feedback based on the first feedback message and the at least second feedback message, and can adjust a sidelink operating parameter based on the aggregate feedback, wherein communication with the second UE via the sidelink channel is based on the adjustment.

[0166] Additionally or alternatively, the sidelink parameter adjuster 635 may determine an aggregate multicast packet error rate, an aggregate multicast bit rate, or both at a set of different distances based on the first feedback message and at least the second feedback message, and may adjust the sidelink operating parameters based on the aggregate multicast packet error rate, the aggregate multicast bit rate, or both, wherein communication with the second UE via the sidelink channel is based on the adjustment.

[0167] In some examples, the sidelink parameter adjuster 635 may adjust the sidelink operating parameters by adjusting the feedback distance threshold based on the sidelink channel congestion indicator, and may send a feedback message that negatively confirms the sidelink data transmission based on the distance between the first UE and the second UE satisfying the adjusted feedback distance threshold to trigger retransmission of the sidelink data transmission performed by the second UE.

[0168] The combined feedback package component 640 may receive a combined feedback package including a first feedback message corresponding to the sidelink data transmission and at least a second feedback message for at least one additional wireless device from a second UE, and may parse the first feedback message from the combined feedback package, wherein the communication with the second UE via the sidelink channel is based on the first feedback message. Additionally or alternatively, the combined feedback package component 640 may send a combined feedback package including the first feedback message corresponding to the sidelink data transmission and at least the second feedback message for at least one additional wireless device to the second UE. In some cases, the combined feedback package may include a receiver-side congestion index for at least one QoS category.

[0169] The feedback transmitter 655 may send a feedback message for the sidelink data transmission, the feedback message including the geolocation data of the first UE and an indication of one or more packets received in the time interval, wherein the communication with the second UE via the sidelink channel is based on the feedback message. In some examples, the feedback transmitter 655 may send a feedback message for the sidelink data transmission to the second UE via the sidelink channel, the feedback message including one or more of the following: an identifier of the second UE, PER, bit rate, feedback cycle start, feedback cycle end, a packet identifier of the first packet received in the cycle, a packet identifier of the last packet received in the cycle, positioning data of the first UE, orientation data of the first UE, speed data of the first UE, a distance between the first UE and the second UE, or any combination thereof, wherein the communication with the second UE via the sidelink channel is based on the feedback message.

[0170] Additionally or alternatively, the feedback transmitter 655 may send a MACCE including a feedback message for a sidelink data transmission, wherein the communication with the second UE via the sidelink channel is based on the feedback message. In some examples, the feedback transmitter 655 may send an uplink data transmission including a feedback message for a sidelink data transmission to the second UE, wherein the communication with the second UE via the sidelink channel is based on the feedback message. Additionally or alternatively, the feedback transmitter 655 may send a feedback message for a sidelink data transmission including a sidelink channel congestion indicator to the second UE, wherein the communication with the second UE via the sidelink channel is based on the feedback message.

[0171] Figure 7A diagram of a system 700 including a device 705 supporting feedback for sidelink transmissions according to aspects of the present disclosure is shown. The device 705 may be an example of a device 405, a device 505, or a UE 115 as described herein or include a component of the device 505, a device 605, or a UE 115. The device 705 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 710, an I / O controller 715, a transceiver 720, an antenna 725, a memory 730, and a processor 740. These components may communicate electronically via one or more buses (e.g., a bus 745).

[0172] The communication manager 710 may send a sidelink data transmission to the second UE via the sidelink channel. In some cases, the communication manager 710 may receive a sidelink channel congestion indicator from the second UE via the sidelink channel. Thus, the communication manager 710 may communicate with the second UE via the sidelink channel according to the sidelink operating parameters adjusted based on the sidelink channel congestion indicator.

[0173] Additionally or alternatively, the communication manager 710 may monitor the sidelink channel to obtain a sidelink data transmission from the second UE. In some cases, the communication manager 710 may send a sidelink channel congestion indicator to the second UE via the sidelink channel. Thus, the communication manager 710 may communicate with the second UE via the sidelink channel according to the sidelink operating parameters adjusted based on the sidelink channel congestion indicator.

[0174] I / O controller 715 can manage input and output signals for device 705. I / O controller 715 can also manage peripheral devices that are not integrated into device 705. In some cases, I / O controller 715 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 715 can utilize an operating system, such as Or another well-known operating system. In other cases, I / O controller 715 can represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 715 can be implemented as part of a processor. In some cases, a user can interact with device 705 via I / O controller 715 or via hardware components controlled by I / O controller 715.

[0175] As described above, the transceiver 720 can communicate bidirectionally via one or more antennas, wired or wireless links. For example, the transceiver 720 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 720 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.

[0176] In some cases, a wireless device may include a single antenna 725. However, in some cases, a device may have more than one antenna 725, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0177] The memory 730 may include random access memory (RAM) and read-only memory (ROM). The memory 730 may store computer-readable, computer-executable code 735 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 730 may also contain, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral device components or devices.

[0178] Processor 740 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 740 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into processor 740. Processor 740 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 730) to cause device 705 to perform various functions (e.g., functions or tasks to support feedback of sidelink transmissions).

[0179] The code 735 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 735 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 735 may not be directly executable by the processor 740, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0180] Figure 8 A flow chart illustrating a method 800 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The operations of the method 800 may be implemented by a UE 115 or a component thereof as described herein. In some examples, the operations of the method 800 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7The communication manager described in the embodiment of the present invention performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0181] At 805, the UE may send a sidelink data transmission to a second UE via a sidelink channel. The operations of 805 may be performed according to the methods described herein. In some examples, aspects of the operations of 805 may be as described in reference to Figures 4 to 7 The sidechain data transmitter implementation is described.

[0182] At 810, the UE may receive a sidelink channel congestion indicator from a second UE via a sidelink channel. The operations of 810 may be performed according to the methods described herein. In some examples, aspects of the operations of 810 may be performed as described in reference to Figures 4 to 7 Describes the implementation of the congestion indicator component.

[0183] At 815, the UE may communicate with a second UE via the sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The operations of 815 may be performed according to the methods described herein. In some examples, aspects of the operations of 815 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0184] Fig. 9 A flow chart illustrating a method 900 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The operations of the method 900 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 900 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 The communication manager described in the embodiment of the present invention performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0185] At 905, the UE may send a sidelink data transmission to a second UE via a sidelink channel. The operations of 905 may be performed according to the methods described herein. In some examples, aspects of the operations of 905 may be as described in reference to Figures 4 to 7 The sidechain data transmitter implementation is described.

[0186] At 910, the UE may receive a sidelink channel congestion indicator from a second UE via a sidelink channel. The operations of 910 may be performed according to the methods described herein. In some examples, aspects of the operations of 910 may be performed as described in reference to Figures 4 to 7 Describes the implementation of the congestion indicator component.

[0187] At 915, the UE may communicate with a second UE via the sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The operations of 915 may be performed according to the methods described herein. In some examples, aspects of the operations of 915 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0188] At 920, the UE may communicate with a second UE via a sidelink channel according to a sidelink operation parameter, the sidelink operation parameter being one or more of: a number of retransmissions parameter, a feedback distance parameter, a distance parameter, a control exclusion distance parameter, a reference signal received power parameter, a control exclusion reference signal received power parameter, or any combination thereof. The operations of 920 may be performed according to the methods described herein. In some examples, aspects of the operations of 920 may be performed as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0189] Fig.10 A flow chart illustrating a method 1000 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The operations of the method 1000 may be implemented by a UE 115 or a component thereof as described herein. In some examples, the operations of the method 1000 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 The communication manager described in the embodiment of the present invention performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0190] At 1005, the UE may send a congestion indicator configuration to a second UE via a sidelink channel, wherein the sidelink channel congestion indicator is based on the congestion indicator configuration. The operations of 1005 may be performed according to the methods described herein. In some examples, aspects of the operations of 1005 may be as described in reference to Figures 4 to 7 Describes the congestion indicator configuration component implementation.

[0191] At 1010, the UE may send a sidelink data transmission to a second UE via a sidelink channel. The operations of 1010 may be performed according to the methods described herein. In some examples, aspects of the operations of 1010 may be as described in reference to Figures 4 to 7 The sidechain data transmitter implementation is described.

[0192] At 1015, the UE may receive a sidelink channel congestion indicator from a second UE via the sidelink channel. The operations of 1015 may be performed according to the methods described herein. In some examples, aspects of the operations of 1015 may be performed as described in reference to Figures 4 to 7 Describes the implementation of the congestion indicator component.

[0193] At 1020, the UE may communicate with a second UE via a sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The operations of 1020 may be performed according to the methods described herein. In some examples, aspects of the operations of 1020 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0194] Fig.11 A flow chart illustrating a method 1100 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The operations of the method 1100 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1100 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 The communication manager described in the embodiment of the present invention performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0195] At 1105, the UE may send a sidelink data transmission to a second UE via a sidelink channel. The operations of 1105 may be performed according to the methods described herein. In some examples, aspects of the operations of 1105 may be as described in reference to Figures 4 to 7 The sidechain data transmitter implementation is described.

[0196] At 1110, the UE may receive a sidelink channel congestion indicator from a second UE via a sidelink channel. 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 4 to 7 Describes the implementation of the congestion indicator component.

[0197] At 1115, the UE may adjust the sidelink operating parameters by adjusting one or more of a feedback distance threshold, a control exclusion range threshold, an input data rate, or any combination thereof based at least in part on the sidelink channel congestion indicator, wherein the communication with the second UE via the sidelink channel is based on the adjustment. The operations of 1115 may be performed according to the methods described herein. In some examples, aspects of the operations of 1115 may be performed as described in reference to Figures 4 to 7 Describes the implementation of the sidechain parameter adjuster.

[0198] At 1120, the UE may communicate with a second UE via a sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The operations of 1120 may be performed according to the methods described herein. In some examples, aspects of the operations of 1120 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0199] Fig.12A flow chart illustrating a method 1200 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The operations of the method 1200 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1200 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 The communication manager described in the embodiment of the present invention performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0200] At 1205, the UE may monitor the sidelink channel for sidelink data transmission from the second UE. 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 4 to 7 The sidechain channel monitoring component described here performs

[0201] At 1210, the UE may send a sidelink channel congestion indicator to a second UE via a sidelink channel. 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 4 to 7 Describes the congestion indicator implementation.

[0202] At 1215, the UE may communicate with the second UE via the sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The operations of 1215 may be performed according to the methods described herein. In some examples, aspects of the operations of 1215 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0203] Fig.13 A flow chart illustrating a method 1300 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The operations of the method 1300 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1300 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 The communication manager described in the embodiment of the present invention performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0204] At 1305, the UE may monitor the sidelink channel for sidelink data transmission from the second UE. 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 4 to 7 The sidechain channel monitoring component described here is implemented.

[0205] At 1310, the UE may send a sidelink channel congestion indicator to a second UE via a sidelink channel. 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 4 to 7 Describes the congestion indicator implementation.

[0206] At 1315, the UE may communicate with the second UE via the sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0207] At 1320, the UE may monitor retransmissions of sidelink data transmissions sent from the second UE via the sidelink channel based on the sidelink operating parameters. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0208] Fig.14 A flow chart illustrating a method 1400 for supporting feedback of sidelink transmissions according to aspects of the present disclosure is shown. The operations of the method 1400 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1400 may be implemented by a UE 115 or a component thereof as described herein. Figures 4 to 7 The communication manager described in the embodiment of the present invention performs. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0209] At 1405, the UE may monitor the sidelink channel for sidelink data transmission from the second UE. 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 4 to 7 The sidechain channel monitoring component described here is implemented.

[0210] At 1410, the UE may send a sidelink channel congestion indicator to a second UE via a sidelink channel. 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 4 to 7 Describes the congestion indicator implementation.

[0211] At 1415, the UE may communicate with a second UE via the sidelink channel according to the sidelink operation parameters adjusted based on the sidelink channel congestion indicator. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be as described in reference to Figures 4 to 7 Described sidechain communicator implementation.

[0212] At 1420, the UE may adjust the sidelink operating parameters by adjusting one or more of a feedback distance threshold, a control exclusion range threshold, an input data rate, or any combination thereof based at least in part on the sidelink channel congestion indicator, wherein the communication with the second UE via the sidelink channel is based on the adjustment. 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 4 to 7 Describes the implementation of the sidechain parameter adjuster.

[0213] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified, and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0214] The technology described herein can be used in various wireless communication systems, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) and other systems. CDMA systems can implement radio technologies such as CDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 release is commonly referred to as CDMA20001x, 1x, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Speed ​​Packet Data (HRPD), etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. TDMA systems can implement radio technologies such as Global System for Mobile Communications (GSM).

[0215] OFDMA systems can implement radio technologies such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS). LTE, LTE-A, and LTE-A Pro are versions of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, LTE-A Pro, NR, and GSM are described in documents from an organization named "3rd Generation Partnership Project" (3GPP). CDMA2000 and UMB are described in documents from an organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein can be used for the systems and radio technologies mentioned herein as well as other systems and radio technologies. Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may be applicable beyond LTE, LTE-A, LTE-A Pro, or NR applications.

[0216] A macro cell typically covers a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access to UEs with service subscriptions to a network provider. Compared to a macro cell, a small cell may be associated with a low-power base station, and the small cell may operate in the same or different (e.g., licensed, unlicensed, etc.) frequency band as the macro cell. According to various examples, a small cell may include a pico cell, a femto cell, and a micro cell. For example, a pico cell may cover a small geographic area and may allow unrestricted access to UEs with service subscriptions to a network provider. A femto cell may also cover a small geographic area (e.g., a home) and may provide restricted access to UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in a home, etc.). An eNB for a macro cell may be referred to as a macro eNB. An eNB for a small cell may be referred to as a small cell eNB, a pico eNB, a femto eNB, or a home eNB. An eNB may support one or more (e.g., two, three, four, etc.) cells and may also support communications using one or more component carriers.

[0217] The wireless communication system described herein may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. The techniques described herein may be used for synchronous or asynchronous operation.

[0218] 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 referred to throughout the specification may be represented by voltage, current, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0219] The various illustrative blocks and modules described in conjunction with the disclosure herein may be implemented or executed with a general purpose processor, a DSP, an ASIC, an FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. 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, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0220] 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 this 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 a combination of any of these. Features that implement the functions may also be physically located in various locations, including being distributed so that portions of the functions are implemented in different physical locations.

[0221] Computer-readable media include both non-transitory computer storage media and communication media, and communication media include any media that facilitates the transfer of computer programs from one place to another.Non-transitory storage media can be any available media that can be accessed by a general or special-purpose computer.As an example and not limitation, non-transitory computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage devices, or can be used to carry or store required program code components in the form of instructions or data structures and can be accessed by a general or special-purpose computer or a general or special-purpose processor.Any connection is properly referred to as computer-readable media.For example, if 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 technologies such as infrared, radio and microwaves, coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwaves are included in the definition of medium. As used herein, disk and disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0222] As used herein, including in the claims, "or" used in a list of items (e.g., a list of items terminated by 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 means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an exemplary 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."

[0223] 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 that distinguishes between similar components. If only the first reference number is used in the specification, the specification applies to any of the similar components having the same first reference number, regardless of the second or other subsequent reference numbers.

[0224] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that may be implemented or within the scope of the claims. The term "exemplary" 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 technology, the detailed description includes specific details. However, these technologies may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0225] The description herein is provided to enable those skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled 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 limited to the examples and designs described herein, but will be given the broadest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication by a first user equipment (UE), comprising: sending a sidelink data transmission to a second UE via a sidelink channel; receiving a combined feedback packet from the second UE via the sidelink channel, the combined feedback packet comprising a first feedback message corresponding to the sidelink data transmission and a second feedback message for at least one additional wireless device; as well as The first feedback message is parsed from the combined feedback packet, and the second UE is communicated via the sidelink channel according to a sidelink operating parameter adjusted based at least in part on a sidelink channel congestion indicator in the first feedback message.

2. The method according to claim 1, wherein: Communicating with the second UE via the sidelink channel includes: Communicate with the second UE via the sidelink channel according to the sidelink operation parameter, where the sidelink operation parameter is one or more of the following: a number of retransmission parameters, a feedback distance parameter, a distance parameter, a control exclusion distance parameter, a reference signal received power parameter, a control exclusion reference signal received power parameter, or any combination thereof.

3. The method according to claim 1, wherein: Communicating with the second UE via the sidelink channel includes: The sidelink data transmission is retransmitted to the second UE via the sidelink channel based at least in part on the sidelink operating parameters.

4. The method according to claim 1, further comprising: A congestion indicator configuration is sent to the second UE via the sidelink channel, wherein the sidelink channel congestion indicator is based at least in part on the congestion indicator configuration.

5. The method according to claim 4, wherein: Sending the congestion indicator configuration includes: The congestion indicator configuration is sent to indicate the periodicity of the second UE reporting the sidelink channel congestion indicator.

6. The method according to claim 4, wherein: Sending the congestion indicator configuration includes: The congestion indicator configuration is sent to indicate an event, after detecting the event the second UE is to report the sidelink channel congestion indicator.

7. The method according to claim 1, wherein: The sidelink channel congestion indicator is received according to a congestion indicator configuration, and wherein the first UE is configured by a network device having the congestion indicator configuration or the first UE is pre-configured with the congestion indicator configuration.

8. The method according to claim 1, wherein: Sending the side chain data transmission comprises: The sidelink data transmission is sent, the sidelink data transmission comprising geolocation data of the first UE and one or more packet indexes of one or more packets included in the sidelink data transmission.

9. The method of claim 1, wherein the first feedback message comprises geolocation data of the second UE and an indication of one or more packets received in a time interval, wherein: The communication with the second UE via the sidelink channel is based at least in part on the first feedback message.

10. The method according to claim 1, further comprising: The sidelink operating parameter is adjusted by adjusting a feedback distance threshold based at least in part on the sidelink channel congestion indicator, wherein the communication via the sidelink channel satisfies the adjusted feedback distance threshold based at least in part on a distance between the first UE and the second UE.

11. The method according to claim 1, further comprising: The sidelink operating parameter is adjusted by adjusting one or more of a feedback distance threshold, a control exclusion range threshold, an input data rate, or any combination thereof based at least in part on the sidelink channel congestion indicator, wherein the communication with the second UE via the sidelink channel is based at least in part on the adjustment.

12. The method according to claim 1, wherein: The first feedback message provides an indication of one or more packets received within a time interval, and the method further comprises: generating a correction indication of the one or more packets received in the time interval based at least in part on processing the first feedback message to determine that the second UE did not receive one or more additional packets, wherein the communication with the second UE via the sidelink channel is based at least in part on the correction indication.

13. The method according to claim 1, wherein: The combined feedback packet includes a receiver-side congestion index for at least one quality of service class.

14. The method according to claim 1, wherein: The first feedback message includes one or more of the following: an identifier of the first UE, a packet error rate, a bit rate, a feedback cycle start, a feedback cycle end, a packet identifier of a first packet received within a cycle, a packet identifier of a last packet received within a cycle, positioning data of the second UE, orientation data of the second UE, speed data of the second UE, a distance between the first UE and the second UE, or any combination thereof, wherein the communication with the second UE via the sidelink channel is at least partially based on the first feedback message.

15. The method according to claim 1, further comprising: A medium access control (MAC) control element (CE) is received including the first feedback message, wherein the communication with the second UE via the sidelink channel is based at least in part on the first feedback message.

16. The method according to claim 1, further comprising: An uplink data transmission including the first feedback message is received from the second UE, wherein the communication with the second UE via the sidelink channel is based at least in part on the first feedback message.

17. The method according to claim 1, The first feedback message includes the sidelink channel congestion indicator, wherein: The communication with the second UE via the sidelink channel is based at least in part on the first feedback message.

18. The method according to claim 1, wherein: Sending the side chain data transmission comprises: The sidechain data transmission is sent as a connectionless sidechain multicast data transmission.

19. A method for wireless communication by a first user equipment (UE), comprising: sending a sidelink data transmission to a second UE via a sidelink channel; receiving, via the sidelink channel, a first feedback message for the sidelink data transmission from the second UE and at least a second feedback message from at least a third UE; determining aggregate feedback based at least in part on the first feedback message and at least the second feedback message, the aggregate feedback comprising an aggregate congestion index; adjusting a sidechain operating parameter based at least in part on the aggregate feedback and the aggregate congestion index included in the aggregate feedback; and Based at least in part on the adjusted sidelink operating parameter, communicating with the second UE via the sidelink channel.

20. A method for wireless communication by a first user equipment (UE), comprising: sending a sidelink data transmission to a second UE via a sidelink channel; receiving, via the sidelink channel, a first feedback message for the sidelink data transmission from the second UE and at least a second feedback message from at least a third UE; determining an aggregate multicast packet error rate, an aggregate multicast bit rate, or both at a plurality of different distances based at least in part on the first feedback message and at least the second feedback message; adjusting a sidechain operating parameter based at least in part on the aggregate multicast packet error rate, the aggregate multicast bit rate, or both; and Based at least in part on the adjusted sidelink operating parameter, communicating with the second UE via the sidelink channel.

21. A method for wireless communication by a first user equipment (UE), comprising: monitoring a sidelink channel for a first sidelink data transmission from a second UE and a second sidelink data transmission from a third UE; In response to the monitoring, sending, via the sidelink channel, to the second UE, a first sidelink channel congestion indicator associated with the first sidelink data transmission and a second sidelink channel congestion indicator associated with the second sidelink data transmission; as well as Communicating with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based at least in part on the first sidelink channel congestion indicator sent to the second UE.

22. The method according to claim 21, wherein: Communicating with the second UE via the sidelink channel includes: Communicate with the second UE via the sidelink channel according to the sidelink operation parameter, where the sidelink operation parameter is one or more of the following: a number of retransmission parameters, a feedback distance parameter, a distance parameter, a control exclusion distance parameter, a reference signal received power parameter, a control exclusion reference signal received power parameter, or any combination thereof.

23. The method according to claim 21, wherein: Communicating with the second UE via the sidelink channel includes: Monitoring retransmissions of the first sidelink data transmission from the second UE via the sidelink channel based at least in part on the sidelink operating parameters.

24. The method of claim 21, further comprising: A congestion indicator configuration is received from the second UE via the sidelink channel, wherein the first sidelink channel congestion indicator is sent to the second UE based at least in part on the congestion indicator configuration.

25. The method according to claim 24, wherein: Receiving the congestion indicator configuration includes: The congestion indicator configuration is received indicating a periodicity with which the first UE is to report the first sidelink channel congestion indicator.

26. The method according to claim 24, wherein: Receiving the congestion indicator configuration includes: The congestion indicator configuration is received indicating an event, upon detection of which the first UE is to report the first sidelink channel congestion indicator.

27. The method of claim 21, wherein: The first sidelink channel congestion indicator is sent to the second UE according to a congestion indicator configuration, and wherein the first UE is configured by a network device having the congestion indicator configuration, or the first UE is pre-configured with the congestion indicator configuration.

28. An apparatus for wireless communication by a first user equipment (UE), comprising: means for sending a sidelink data transmission to a second UE via a sidelink channel; means for receiving a combined feedback packet from the second UE via the sidelink channel, the combined feedback packet comprising a first feedback message corresponding to the sidelink data transmission and a second feedback message for at least one additional wireless device; as well as means for parsing the first feedback message from the combined feedback packet and communicating with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based at least in part on a sidelink channel congestion indicator in the first feedback message.

29. An apparatus for wireless communication by a first user equipment (UE), comprising: means for sending a sidelink data transmission to a second UE via a sidelink channel; means for receiving, via the sidelink channel, a first feedback message for the sidelink data transmission from the second UE and at least a second feedback message from at least a third UE; means for determining aggregate feedback based at least in part on the first feedback message and at least the second feedback message, the aggregate feedback comprising an aggregate congestion index; means for adjusting sidechain operating parameters based at least in part on the aggregate feedback and the aggregate congestion index included in the aggregate feedback; as well as means for communicating with the second UE via the sidelink channel based at least in part on the adjusted sidelink operating parameter.

30. An apparatus for wireless communication by a first user equipment (UE), comprising: means for sending a sidelink data transmission to a second UE via a sidelink channel; means for receiving, via the sidelink channel, a first feedback message for the sidelink data transmission from the second UE and at least a second feedback message from at least a third UE; means for determining an aggregate multicast packet error rate, an aggregate multicast bit rate, or both at a plurality of different distances based at least in part on the first feedback message and at least the second feedback message; means for adjusting a sidelink operating parameter based at least in part on the aggregate multicast packet error rate, the aggregate multicast bit rate, or both; as well as means for communicating with the second UE via the sidelink channel based at least in part on the adjusted sidelink operating parameter.

31. An apparatus for wireless communication by a first user equipment (UE), comprising: means for monitoring a sidelink channel for a first sidelink data transmission from a second UE and a second sidelink data transmission from a third UE; means for transmitting, in response to the monitoring, to the second UE via the sidelink channel a first sidelink channel congestion indicator associated with the first sidelink data transmission and a second sidelink channel congestion indicator associated with the second sidelink data transmission; as well as means for communicating with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based at least in part on the first sidelink channel congestion indicator sent to the second UE.

32. An apparatus for wireless communication by a first user equipment (UE), comprising: one or more processors; one or more memories coupled to the one or more processors; as well as Instructions stored in the one or more memories and executable by the one or more processors to cause the device to: sending a sidelink data transmission to a second UE via a sidelink channel; receiving a combined feedback packet from the second UE via the sidelink channel, the combined feedback packet comprising a first feedback message corresponding to the sidelink data transmission and a second feedback message for at least one additional wireless device; as well as The first feedback message is parsed from the combined feedback packet, and the second UE is communicated via the sidelink channel according to a sidelink operating parameter adjusted based at least in part on a sidelink channel congestion indicator in the first feedback message.

33. An apparatus for wireless communication by a first user equipment (UE), comprising: one or more processors; one or more memories coupled to the one or more processors; as well as Instructions stored in the one or more memories and executable by the one or more processors to cause the device to: sending a sidelink data transmission to a second UE via a sidelink channel; receiving, via the sidelink channel, a first feedback message for the sidelink data transmission from the second UE and at least a second feedback message from at least a third UE; determining aggregate feedback based at least in part on the first feedback message and at least the second feedback message, the aggregate feedback comprising an aggregate congestion index; adjusting a sidechain operating parameter based at least in part on the aggregate feedback and the aggregate congestion index included in the aggregate feedback; and Based at least in part on the adjusted sidelink operating parameter, communicating with the second UE via the sidelink channel.

34. An apparatus for wireless communication by a first user equipment (UE), comprising: one or more processors; one or more memories coupled to the one or more processors; as well as Instructions stored in the one or more memories and executable by the one or more processors to cause the device to: sending a sidelink data transmission to a second UE via a sidelink channel; receiving, via the sidelink channel, a first feedback message for the sidelink data transmission from the second UE and at least a second feedback message from at least a third UE; determining an aggregate multicast packet error rate, an aggregate multicast bit rate, or both at a plurality of different distances based at least in part on the first feedback message and at least the second feedback message; adjusting a sidechain operating parameter based at least in part on the aggregate multicast packet error rate, the aggregate multicast bit rate, or both; and Based at least in part on the adjusted sidelink operating parameter, communicating with the second UE via the sidelink channel.

35. An apparatus for wireless communication by a first user equipment (UE), comprising: one or more processors; one or more memories coupled to the one or more processors; as well as Instructions stored in the one or more memories and executable by the one or more processors to cause the device to: monitoring a sidelink channel for a first sidelink data transmission from a second UE and a second sidelink data transmission from a third UE; In response to the monitoring, sending, via the sidelink channel, to the second UE, a first sidelink channel congestion indicator associated with the first sidelink data transmission and a second sidelink channel congestion indicator associated with the second sidelink data transmission; as well as Communicating with the second UE via the sidelink channel according to a sidelink operating parameter adjusted based at least in part on the first sidelink channel congestion indicator sent to the second UE.

36. A computer-readable medium having program code recorded thereon, wherein the program code is executable by one or more processors of a user device to cause the processors to perform the method of any one of claims 1-27.

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