Sidelink multicast configuration for supporting feedback control

Abstract

The invention relates to sidelink multicast configuration for supporting feedback control. Methods, systems, and devices are described for wireless communication in which a user equipment (UE) may communicate with one or more other UEs using sidelink communication. A plurality of UEs may form a group of sidelink communications and provide sidelink multicast communications in which an identification of a UE is determined based at least in part on a member identification of the UE within the group. Each UE in the group may determine feedback resources for acknowledgement feedback within the group based on the UE identification and a size of the group.

Description

[0001] This application is a divisional application of the invention patent application entitled “Sidelink multicast configuration for supporting feedback control” with application date September 25, 2020 and application number 202080068140.6.

[0002] Cross-references

[0003] This patent application claims priority to U.S. patent application No. 17 / 031,768, entitled “SIDELINK GROUPCAST ​​CONFIGURATION TO SUPPORT FEEDBACK CONTROL,” filed by CHENG et al. on September 24, 2020, which U.S. patent application claims the benefit of U.S. Provisional Patent Application No. 62 / 909,718, entitled “SIDELINK GROUPCAST ​​CONFIGURATION TO SUPPORT FEEDBACK CONTROL,” filed by CHENG et al. on October 2, 2019, which applications are assigned to the assignee of this application. Technical Field

[0004] The following relates generally to wireless communications and, more particularly, to sidelink multicast configurations.

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, 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 use various technologies, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include several base stations or network access nodes, each of which simultaneously supports the communication of multiple communication devices, which may be referred to as user equipment (UE). Summary of the invention

[0006] A method for wireless communication at a first UE is described. The method may include receiving side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least the first UE and the second UE. The method may also include: determining, at the first UE, an identifier for communicating with the first side link group based on the side link multicast information; and communicating with the first side link group based on the determined identifier.

[0007] A device for wireless communication at a first UE is described. The device may include a processor and a memory coupled to the processor. The processor and the memory may be configured to cause the device to receive side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least the first UE and the second UE. The processor and the memory may also be configured to cause the device to: determine an identifier for communicating with the first side link group based on the side link multicast information at the first UE; and communicate with the first side link group based on the determined identifier.

[0008] Another apparatus for wireless communication at a first UE is described. The apparatus may include means for receiving side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE within the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least the first UE and the second UE. The apparatus may also include means for determining, at the first UE, an identifier for communicating with the first side link group based on the side link multicast information; and communicating with the first side link group based on the determined identifier.

[0009] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor for the following operations: receiving side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least a first UE and a second UE. The code may also include instructions executable by a processor for the following operations: determining, at the first UE, an identifier for communicating with the first side link group based on the side link multicast information; and communicating with the first side link group based on the determined identifier.

[0010] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the identifier is a source layer 2 identifier, and the member identifier of the first UE is included as a first bit subset of the source layer 2 identifier. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the side link multicast information further includes a group identifier of the first side link group. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the group identifier is mapped to a second bit subset of the destination layer 2 identifier. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: determining a layer 1 identifier based on a source layer 2 identifier, wherein the layer 1 identifier is indicated in a physical layer control information transmission to the first side link group. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the layer 1 identifier corresponds to a subset of the source layer 2 identifier indicating a group identifier of the first side link group and a member identifier of the first UE within the first side link group. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, a number of bits of the first subset of bits is determined based on a group size of the first side link group.

[0011] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: determining whether to use a separate feedback resource by each of the multiple members of the first side link group for providing confirmation feedback information to other members of the multiple members of the first side link group based on the group size of the first side link group. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first UE determines whether to use a separate feedback resource or a shared feedback resource to provide confirmation feedback information based on whether the number of multiple members of the first side link group is higher than a threshold number of members. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first UE determines whether to use a separate feedback resource or a shared feedback resource to provide confirmation feedback information based on pre-configuration of the first UE, control signaling received from another UE or base station, or any combination thereof. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, a first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based on radio resource control (RRC) signaling received at the first UE, a system information block (SIB) received at the first UE, a media access control (MAC) control element received at the first UE, or any combination thereof.

[0012] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: determining a feedback resource set for transmitting confirmation feedback information to one or more members of the first side link group based at least in part on the group size of the first side link group and the member identification of the first UE within the first side link group. Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: receiving a first multicast communication from a second UE, determining confirmation feedback for the first multicast communication, and transmitting confirmation feedback for the first multicast communication to the second UE using the feedback resource set.

[0013] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: transmitting multicast communications to other members of the plurality of members of the first side link group, monitoring confirmation feedback from other members of the plurality of members of the first side link group, and determining to retransmit the multicast communications based on confirmation feedback from at least one member of the plurality of members of the first side link group. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, determining to retransmit may further include operations, features, devices, or instructions for the following actions: determining that at least one member of the plurality of members of the first side link group provides a negative confirmation, determining that confirmation feedback from at least one member of the plurality of members of the first side link group is not received at the first UE, or any combination thereof.

[0014] Some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein may further include operations, features, means, or instructions for configuring an access layer layer at a first UE for a quality of service (QoS) flow for multicast communications associated with a layer 2 identifier, and wherein the access layer layer determines a QoS flow identifier and a QoS context, and derives a layer 1 identifier for the QoS flow. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the sidelink multicast information is received at an application layer of the first UE or at a group management middleware layer of the first UE.

[0015] A method for wireless communication at a first UE is described. The method may include: configuring a first side link group for side link multicast communication, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determining a member identifier of the first UE; determining a feedback resource configuration for the side link group based on a group size of the first side link group and the determined member identifier of the first UE; and transmitting side link multicast information indicating at least the feedback resource configuration to other members of the multiple members of the first side link group. The method may also include: determining, at the first UE, an identifier for communicating with the first side link group based on the side link multicast information; and communicating with the first side link group based on the determined identifier and the feedback resource configuration.

[0016] A device for wireless communication at a first UE is described. The device may include a processor and a memory coupled to the processor. The processor and the memory may be configured to enable the device to: configure a first side link group for side link multicast communication, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determine a member identifier for the first UE; determine a feedback resource configuration for the side link group based on the group size of the first side link group and the determined member identifier of the first UE, wherein the feedback resource configuration includes a shared feedback resource used by multiple members or a separate feedback resource corresponding to each of the multiple members, and transmit side link multicast information indicating at least the feedback resource configuration to other members of the multiple members of the first side link group. The processor and the memory may also be configured to enable the device to: determine an identifier for communicating with the first side link group based on the side link multicast information at the first UE; and communicate with the first side link group based on the determined identifier and the feedback resource configuration.

[0017] Another device for wireless communication at a first UE is described. The device may include a device for the following operations: configuring a first side link group for side link multicast communication, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determining a member identifier of the first UE; determining a feedback resource configuration for the side link group based on the group size of the first side link group and the determined member identifier of the first UE; and transmitting side link multicast information indicating at least the feedback resource configuration to other members of the multiple members of the first side link group. The device may also include a device for the following operations: determining an identifier for communicating with the first side link group based on the side link multicast information at the first UE; and communicating with the first side link group based on the determined identifier and the feedback resource configuration.

[0018] A non-transitory computer-readable medium storing code for wireless communication at a first UE is described. The code may include instructions executable by a processor for the following operations: configuring a first side link group for side link multicast communication, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determining a member identifier of the first UE; determining a feedback resource configuration for the side link group based on the group size of the first side link group and the determined member identifier of the first UE; and transmitting side link multicast information indicating at least the feedback resource configuration to other members of the multiple members of the first side link group. The code may also include instructions executable by a processor for the following operations: determining an identifier for communicating with the first side link group based on the side link multicast information at the first UE; and communicating with the first side link group based on the determined identifier and the feedback resource configuration.

[0019] In some examples of the methods, apparatuses (devices) and non-transient computer-readable media described herein, the feedback resource configuration includes a shared feedback resource used by multiple members or a separate feedback resource corresponding to each of the multiple members. In some examples of the methods, apparatuses (devices) and non-transient computer-readable media described herein, when the number of multiple members of the first side link group is at or below the threshold number of members, a separate feedback resource is used to provide confirmation feedback information, and when the number of multiple members of the first side link group exceeds the threshold number of members, a common application resource is used to provide confirmation feedback information. Some examples of the methods, apparatuses (devices) and non-transient computer-readable media described herein may further include operations, features, devices or instructions for the following actions: transmitting multicast communications to other members of the multiple members of the first side link group, monitoring confirmation feedback from other members of the multiple members of the first side link group based on the feedback resource configuration, and determining to retransmit the multicast communication based on confirmation feedback from at least one member of the multiple members of the first side link group. In some examples of the methods, apparatus (devices), and non-transitory computer-readable media described herein, determining to retransmit may further include operations, features, apparatus, or instructions for determining that at least one of the multiple members of the first side link group provides a negative acknowledgment, determining that acknowledgment feedback from at least one of the multiple members of the first side link group is not received at the first UE, or any combination thereof.

[0020] In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based on pre-configuration of the first UE, control signaling received from another UE or base station, or any combination thereof. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based on RRC signaling received at the first UE, SIB received at the first UE, MAC control elements received at the first UE, or any combination thereof. In some examples of the methods, apparatuses (devices), and non-transitory computer-readable media described herein, the number of separate feedback resources corresponds to the number of multiple members of the first side link group minus one.

[0021] In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the side link multicast information further indicates a group identifier of the first side link group, a group size of the first side link group, and a corresponding member identifier within the first side link group of each of the plurality of members. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the identifier is a source layer 2 identifier, and the identifier of the first UE is included as a first bit subset of the source layer 2 identifier, wherein the group identifier is mapped to a second bit subset of the destination layer 2 identifier. Some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein may further include operations, features, devices, or instructions for the following actions: determining a layer 1 identifier based on a source layer 2 identifier, wherein the layer 1 identifier is indicated in a physical layer control information transmission to the first side link group. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the layer 1 identifier corresponds to a subset of the source layer 2 identifier. In some examples of the methods, apparatuses (devices), and non-transient computer-readable media described herein, the number of bits of the first bit subset is determined based on the group size of the first side link group. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1

[0013] An example of a system for supporting a sidelink multicast configuration to support feedback controlled wireless communications in accordance with aspects of the present disclosure is illustrated.

[0023] Figure 2 An example of a wireless communication system supporting a sidelink multicast configuration to support feedback control in accordance with aspects of the present disclosure is illustrated.

[0024] Figure 3 An example of a UE protocol stack supporting sidelink multicast configuration to support feedback control in accordance with aspects of the present disclosure is illustrated.

[0025] Figure 4 An example of a process flow to support sidelink multicast configuration to support feedback control in accordance with aspects of the present disclosure is illustrated.

[0026] Figure 5 and 6 A block diagram of an apparatus supporting a sidelink multicast configuration to support feedback control in accordance with aspects of the present disclosure is shown.

[0027] Figure 7 A block diagram of a communications manager supporting sidelink multicast configuration to support feedback control in accordance with aspects of the present disclosure is shown.

[0028] Figure 8 A diagram of a system including a device supporting a sidelink multicast configuration to support feedback control is shown in accordance with aspects of the present disclosure.

[0029] Figures 9 to 14 A flow chart illustrating a method of supporting sidelink multicast configuration to support feedback control in accordance with aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0030] A wireless communication system may support both access links and side links for communication between wireless devices. An access link may refer to a communication link between a UE and a base station. For example, an access link may support uplink signaling, downlink signaling, connection procedures, etc. A side link may refer to any communication link between similar wireless devices (e.g., a communication link between UEs or a backhaul communication link between base stations). It should be noted that although the various examples provided herein are discussed with respect to UE side link devices, such side link technologies may be used for any type of wireless device using side link communication. For example, a side link may support device-to-device (D2D) communication, vehicle-to-everything (V2X) or vehicle-to-vehicle (V2V) communication, message relay, discovery signaling, beacon signaling, or any combination of these or other signals transmitted from one UE to one or more other UEs across the air.

[0031] As the demand for sidelink communications increases (e.g., due to the growing demand for V2X for autonomous and semi-autonomous vehicles, D2D communications between Internet of Things (IoT) devices, etc.), techniques are needed to efficiently and reliably enhance the throughput and reliability of the sidelink channel. Techniques such as those discussed in various aspects of the present disclosure provide sidelink multicast communications in which an identification of a UE is determined at least in part based on a member identification of the UE within a group. Techniques such as those discussed in one or more aspects of the present disclosure may also provide sidelink multicast communications in which feedback resources for acknowledging feedback are based on the UE identification and the size of the group.

[0032] In some cases, the UE may determine, at least in part based on the size of the group, whether a common set of feedback resources is to be shared among multiple UEs in the group, or whether to configure individual feedback resources for each UE. In some cases, when individual feedback resources are configured for each UE in a sidelink multicast UE group, specific feedback resources for the UE may be determined based on the UE position within the UE group (i.e., the UE identifier relative to the identifiers associated with other UEs in the group) and the size of the group. For example, a first UE (e.g., based on the lowest value of the UE identifier of each member UE of the group) may determine that a first set of feedback resources is to be used to provide confirmation feedback to a second UE of the group. In this case, a third UE (e.g., a UE identifier having a higher value than the second UE) may provide confirmation feedback using a second set of feedback resources determined based on the third UE identifier minus one, because the second UE does not need confirmation feedback resources (i.e., because the second UE is a transmitting UE that receives confirmation feedback from other UEs in the group).

[0033] In some cases, a higher layer (such as an application layer at each UE or a middleware layer at each UE) may provide a UE member ID to a lower layer (e.g., Layer 2) at the UE (e.g., based on communication from a group leader of the UE group). In some implementations, the lower layer may include one or more of a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, or a media access control (MAC) layer at each UE. Subsequently, the identity may be determined based on the UE member ID, the group identity, the group size, or any combination thereof. In some cases, the UE may map its UE member ID to a first subset of bits of the source Layer 2 ID and map the group ID to a second subset of bits in the destination Layer 2 ID.

[0034] Therefore, techniques such as those discussed herein provide enhanced reliability and efficiency in determining UE identification and feedback resources in sidelink multicast communications. For example, by enabling determination of UE identification and feedback resources based on group size or UE identification or both, efficient determination of feedback resources can be provided without the need for additional signaling and associated increased overhead. Further, by determining the source layer 2 ID and the destination layer 2 ID based on the UE member ID and the group ID, respectively, the layer 2 ID can be determined at each UE, which further reduces the signaling and overhead associated with the sidelink multicast configuration. Additionally, in some cases, it can be determined at each UE based on the group size whether a shared feedback resource or a separate feedback resource is used by the UE group, which can also allow for reduced signaling overhead.

[0035] Aspects of the present disclosure are initially described in the context of wireless communication systems. Aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow diagrams related to sidelink multicast configurations to support feedback control.

[0036] Figure 1 An example of a wireless communication system 100 supporting a sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure is illustrated. 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.

[0037] The base stations 105 may be dispersed throughout a geographic area to form the wireless communication system 100, and may be different forms of devices or devices with different capabilities. The base stations 105 and the UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base stations 105 may establish communication links 125. The coverage area 110 may be an example of a geographic area over which the base stations 105 and the UEs 115 support signal communication according to one or more radio access technologies.

[0038] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile, or stationary and mobile at different times. The UEs 115 may be different forms of devices or devices with different capabilities. Figure 1 105. The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment), such as Figure 1 as shown in .

[0039] Each base station 105 may communicate with the core network 130 or communicate with each other or both. For example, the base station 105 may be connected to the core network 130 via a backhaul link 120 (e.g., via S1, N2, N3 or other interfaces). The base station 105 may communicate with each other directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130), or directly and indirectly on the backhaul link 120 (e.g., via X2, Xn or other interfaces). In some examples, the backhaul link 120 may be or include one or more wireless links. The one or more base stations 105 described herein may include or may be referred to by a person of ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a B node, an evolved B node (eNB), a next generation B node or a gigabit B node (any of which may be referred to as a gNB), a home B node, a home evolved B node, or other suitable terms. In some examples, the UE 115 may communicate with the core network 130 via a communication link 135.

[0040] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term, where a "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, etc., which may be implemented in various objects such as appliances, vehicles, meters, etc.

[0041] The UE 115 described herein may be able to communicate with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, relay base stations, etc. Figure 1 as shown in .

[0042] The UE 115 and the base station 105 may communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates according to a physical layer channel for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. The UE 115 may be configured to have multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used in conjunction with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0043] In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a 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 grid for discovery by UE 115. A carrier may operate in a standalone mode in which initial acquisition and connection may be performed by UE 115 via a carrier, or a carrier may operate in a non-standalone mode in which a connection is anchored using a different carrier (e.g., a different carrier of the same or different radio access technology).

[0044] 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. A carrier may carry downlink or uplink communications (e.g., in an FDD mode), or may be configured to carry both downlink and uplink communications (e.g., in a TDD mode).

[0045] A carrier may be associated with a particular bandwidth of a radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as a "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of several predetermined bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)) of a carrier of a particular radio access technology. A device (e.g., a base station 105, a UE 115, or both) of the wireless communication system 100 may have a hardware configuration that supports communications on a particular carrier bandwidth, or may be configurable to support communications on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or a UE 115 that supports simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate on a portion (e.g., a subband, a BWP) or all of a carrier bandwidth.

[0046] The electromagnetic spectrum is typically subdivided into various classes, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz–7.125 GHz) and FR2 (24.25 GHz–52.6 GHz). Frequencies between FR1 and FR2 are typically referred to as mid-band frequencies. Although a portion of FR1 is greater than 6 GHz, FR1 is typically (interchangeably) referred to as the “sub-6 GHz band” in various documents and articles. Similar naming issues sometimes arise regarding FR2, which is typically (interchangeably) referred to as the “millimeter wave” band in various documents and articles, although it is different from the extremely high frequency (EHF) band (30 GHz–300 GHz) identified as the “millimeter wave” band by the International Telecommunication Union (ITU).

[0047] In view of the above aspects, unless otherwise specifically stated, it should be understood that if used in this article, the term "sub-6 GHz" and the like can broadly represent frequencies that can be less than 6 GHz, can be within FR1, or can include mid-band frequencies. In addition, unless otherwise specifically stated, it should be understood that if used in this article, the term "millimeter wave" and the like can broadly represent frequencies that can include mid-band frequencies, can be within FR2, or can be within the EHF band.

[0048] The signal waveform transmitted on the carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system using MCM technology, a resource element may include a code element period (e.g., the duration of a modulation code element) and a subcarrier, where the code element period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, 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 can be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may further improve the data rate or data integrity of communication with UE 115.

[0049] One or more parameter sets for a carrier may be supported, where the parameter set may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into BWPs with the same or different parameter designs. In some examples, a UE 115 may be configured with multiple BWPs. In some cases, a single BWP for a carrier is active at a given time, and communications for a UE 115 may be limited to the active BWP.

[0050] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, and the basic time unit can be, for example, a sampling period T s =1 / (Δf max ·Nf) seconds, where Δf max Nf may represent the maximum supported subcarrier spacing, and Nf may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0051] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some cases, a frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of code element periods (e.g., depending on the length of the cyclic prefix added before each code element period). In some wireless communication systems 100, a time slot may be further divided into a plurality of mini-time slots containing one or more code elements. Excluding the cyclic prefix, each code element period may contain one or more (e.g., N fThe duration of a symbol period may depend on the subcarrier spacing or the operating band.

[0052] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some cases, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0053] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across a system bandwidth or a subset of a system bandwidth of a carrier. One or more control regions (e.g., CORESETs) may be configured for a UE 115. For example, a UE 115 may monitor or search a control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0054] Each base station 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hot spots, or other types of cells, or various combinations thereof). The term "cell" may refer to a logical communication entity used to communicate with a base station 105 (e.g., on a carrier), and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or other) used to distinguish adjacent cells. In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) on which a logical communication entity operates. The range of such a cell may range from a smaller area (e.g., a structure, a subset of a structure) to a larger area depending on various factors (such as the capabilities of the base station 105). For example, a cell may be or include a building, a subset of a building, an external space between or overlapping geographic coverage areas 110, and the like.

[0055] A macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access to UEs 115 that have service subscriptions with a network provider that supports the macro cell. A small cell may be associated with a lower power base station 105 (compared to a macro cell), and the small cell may operate in the same or different (e.g., licensed, unlicensed) frequency band as the macro cell. A small cell may provide unrestricted access to UEs 115 that have service subscriptions with a network provider, or may provide restricted access to UEs 115 associated with the small cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a home or office, etc.). A base station 105 may support one or more cells and may also support communications on one or more cells using one or more component carriers. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access to different types of devices.

[0056] In some examples, base stations 105 may be mobile and thus provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, and the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communication system 100 may include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0057] The wireless communication system 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations 105 may have similar frame timing, and transmissions from different base stations 105 may be approximately aligned in time. For asynchronous operation, the base stations 105 may have different frame timing, and transmissions from different base stations 105 may not be aligned in time in some examples. The techniques described herein may be used for synchronous or asynchronous operation.

[0058] 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 integrate sensors or meters to measure or capture information and relay such information to a central server or application that utilizes the information or presents the information to a person interacting with the application. Some UEs 115 may be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, health care monitoring, field survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0059] 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 unidirectional communication via transmission or reception but not simultaneous transmission and reception). In some examples, half-duplex communication may be performed with a reduced peak rate. Other power saving techniques for UE 115 include entering a power saving deep sleep mode when not engaged in active communications, or operating over a limited bandwidth (e.g., according to narrowband communications), or a combination of these techniques. For example, some UEs 115 may be configured to operate using a narrowband protocol type that is associated with a predefined portion or range (e.g., a subcarrier or resource block (RB) set) within a carrier, within a guard band of a carrier, or outside a carrier.

[0060] The wireless communication system 100 may be configured to support ultra-reliable communication or low latency communication or various combinations thereof. For example, the wireless communication system 100 may be configured to support ultra-reliable low latency communication (URLLC) or mission-critical communication. UE 115 may be designed to support ultra-reliable, low latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication may include private communication or group communication, and may be supported by one or more mission-critical services (such as mission-critical push-to-talk (MCPTT), mission-critical video (MCVideo), or mission-critical data (MCData). Support for mission-critical functions may include prioritization of services, and mission-critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low latency, critical mission, and ultra-reliable low latency may be used interchangeably herein.

[0061] In some cases, UE 115 may also be able to communicate directly with other UE 115 over a device-to-device (D2D) communication link (e.g., using a peer-to-peer (P2P) or D2D protocol). One or more UEs 115 utilizing D2D communication may be within a geographic coverage area 110 of a base station 105. Other UEs 115 in such a 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, each group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, wherein each UE 115 transmits to each other UE 115 in the group. In some examples, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between each UE 115 without involving the base station 105.

[0062] In some systems, a D2D communication link (e.g., a sidelink communication link 140) can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination of these communications. Vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some cases, vehicles in the V2X system can communicate with roadside infrastructure (such as roadside units), or with the network, or with both, using vehicle-to-network (V2N) communication via one or more network nodes (e.g., base station 105). Further, in some cases, multicast communication between groups of UE 115 can be performed via the sidelink communication link 140, and the configuration of identification and feedback resources in the sidelink multicast communication can be performed according to the various aspects discussed herein.

[0063] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), and the EPC or 5GC may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), a user plane function (UPF)) for routing packets or interconnecting to an external network. The control plane entity may manage non-access layer (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by a base station 105 associated with the core network 130. User IP packets may be delivered through a user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to a network operator IP service. The operator IP service may include access to the Internet, an intranet, an IP multimedia subsystem (IMS), or a packet-switched streaming service.

[0064] 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 each UE 115 through several other access network transmission entities, which may be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). Each access network transmission entity may include one or more antenna panels. 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 ANCs) or merged into a single network device (e.g., base station 105).

[0065] The wireless communication system 100 may operate using one or more frequency bands, such as those in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). The 300 MHz to 3 GHz region may be referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from about 1 decimeter to 1 meter long. UHF waves may be blocked or redirected by buildings and environmental features, but these waves may penetrate various structures sufficiently for macro cells to provide service to UEs 115 located indoors. Transmissions using UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) than transmissions using smaller frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0066] The wireless communication system 100 may also operate in a super high frequency (SHF) zone using a frequency band from 3 GHz to 30 GHz (also known as a centimeter band) or in an extremely high frequency (EHF) zone of a spectrum (e.g., from 30 GHz to 300 GHz) (also known as a millimeter band). In some examples, the wireless communication system 100 may support millimeter wave (mmW) communications between UE 115 and base station 105, and the EHF antenna of the corresponding device may be smaller and more closely spaced than the UHF antenna. In some cases, this may facilitate the use of antenna arrays within the device. However, the propagation of EHF transmissions may be subject to even greater atmospheric attenuation and a shorter range than SHF or UHF transmissions. The technology disclosed herein may be adopted across transmissions using one or more different frequency zones, and the use of frequency bands specified across these frequency zones may vary by country or regulatory agency.

[0067] The wireless communication system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communication system 100 may employ licensed assisted access (LAA), LTE unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band). When operating in an unlicensed radio frequency spectrum band, devices (such as base stations 105 and UEs 115) may employ carrier sensing for conflict detection and avoidance. In some cases, operations in an unlicensed band may be based on a carrier aggregation configuration (e.g., LAA) in coordination with component carriers operating in a licensed band. Operations in an unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, D2D transmissions, and the like.

[0068] The base station 105 or UE 115 may be equipped with multiple antennas, which can be used to employ technologies such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of the base station 105 or UE 115 may be located in one or more antenna arrays or antenna panels that can support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly (such as an antenna tower). In some cases, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array having multiple rows and columns of antenna ports that the base station 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that can support various MIMO or beamforming operations. Additionally or alternatively, the antenna panel may support radio frequency beamforming for signals transmitted via the antenna ports.

[0069] The base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectrum efficiency by transmitting or receiving multiple signals via different spatial layers. Such technology may be referred to as spatial multiplexing. For example, the transmitting device may transmit multiple signals via different antennas or different antenna combinations. Similarly, the receiving device may receive multiple signals via different antennas or different antenna combinations. 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 (e.g., different codewords). 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 transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0070] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105 or a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements may include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. Adjustments associated with each antenna element may 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).

[0071] 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 of 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 MAC layer may perform priority handling and multiplex logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmission of 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 that supports radio bearers of user plane data between UE 115 and base station 105 or core network 130. At the physical layer, transport channels may be mapped to physical channels.

[0072] UE 115 and base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. Hybrid automatic repeat request (HARQ) feedback is a technique for increasing the likelihood that data is correctly received on communication link 125. HARQ may 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 may improve the throughput of the MAC layer in poor radio conditions (e.g., low signal-to-noise ratio conditions). In some cases, a device may support simultaneous slot HARQ feedback, wherein the device may provide HARQ feedback in a specific time slot for data received in a previous symbol in the time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0073] One or more base stations 105 may include a base station communication manager, which may configure one or more sidelink parameters for sidelink communication between the first UE 115 and the second UE 115 on the sidelink communication link 140, and transmit a message indicating the one or more sidelink parameters to the one or more sidelink UEs 115.

[0074] UE 115 may include a UE communication manager 102, which may determine side link communication parameters and configurations for side link communication. In some cases, the UE communication manager 102 may receive side link group broadcast information of the side link group from another side link UE 115, and the side link group broadcast information may include group size and UE member identification. Based on the side link group broadcast information, the UE may determine an identification for communicating with the side link group, and communicate with the side link group based at least in part on the determined identification. In some cases, the UE communication manager 102 may determine a feedback resource configuration for the side link group based at least in part on the group size of the side link group, and the feedback resource configuration may include a configuration for providing acknowledgment feedback using a common feedback resource by multiple UEs 115, or wherein the acknowledgment feedback is provided by an individual UE 115 in a separate feedback resource. In the case where a separate feedback resource is configured, a specific UE 115 resource in different available resource sets may be determined based on the group size and the UE position within the group. The UE communication manager 102 may be an example of various aspects of the UE communication manager 810 described herein.

[0075] Figure 2An example of a wireless communication system 200 that supports a sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure is illustrated. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. In some examples, the wireless communication system 200 may include a first UE 115-a, a second UE 115-b, a third UE 115-c, a fourth UE 115-d, and a base station 105, which may be referenced Figure 1 Examples of UEs 115 and base stations 105 are described. In some examples, UE 115-a, UE 115-b, and UE 115-c may be members of group 210 of UEs 115, while UE 115-d may not be part of group 210. One or more of UEs 115 may communicate with base station 105 using corresponding access link 225.

[0076] In this example, the first UE 115-a, the second UE 115-b, and the third UE 115-c may be members of a sidelink multicast communication group, where members of the group may communicate with other members of the group to provide data or other information via the sidelink 205. In some cases, the application layer at the first UE 115-a may prompt the creation of the sidelink multicast communication group, and the group may be established by communication with the application layers of the other UEs 115 in the group. It should be noted that the illustrated sidelink multicast communication group provides communication between three UEs 115, and for simplicity, the communication between these UEs is illustrated in the wireless communication system 200, and the techniques described below may be applicable to other numbers of UEs 115 within the system in which a multicast communication group may be established. Further, the sidelink communication technology may be used for device-to-device communication of wireless devices other than UEs, such as base station communication (e.g., wireless backhaul link between base stations or transmission reception points (TRPs)), communication between access points, etc.

[0077] In some cases, an upper layer application acting to establish a sidelink multicast communication group may provide group information to lower layers (e.g., to a UE access plane layer (AS), which may include layer 2 and layer 1 layers, etc.). Such group information may be used, for example, to determine a HARQ feedback resource to be used by each UE 115 receiving communications in the group. In some cases, such HARQ feedback resources may be common acknowledgment resources shared between multiple UEs 115 (e.g., all UEs 115 receiving a multicast transmission may share the same physical sidelink feedback channel (PSFCH) resources). In other cases, such HARQ resources may include separate acknowledgment feedback resources for different UEs 115 in the group (e.g., each UE 115 receiving a multicast transmission may use a separate PSFCH resource to provide HARQ feedback). In some cases, separate lower layer signaling (e.g., Layer 1 signaling of the physical layer or AS layer at UE 115) may not be provided for multicast communications, and therefore, in order to implement separate PSFCH resources, each UE 115 in the group should be able to individually derive a specific PSFCH to use. Therefore, the AS layer of each group member UE 115 may require an additional identifier from upper layers to support independent selection of PSFCH resources from a list that does not overlap with the PSFCH resources of any other group member.

[0078] For HARQ operations, the AS layer may require an identifier that is unique and can indicate its position in the group. For example, in a group including five members, four PSFCH resources will be required to provide feedback to the transmitting UE 115, and the receiving UE 115 will need to be able to determine which of the four PSFCH resources it will use. In the case where the application layer (e.g., the V2X application layer) provides a group identifier for the sidelink multicast communication group, additional information will be required to identify the unique ID of the UE 115. Therefore, for HARQ operations (such as, based on feedback of acknowledgment (ACK)), the AS layer of each group member UE 115 will also need to be able to determine whether all members have responded so that it can determine whether to perform a retransmission. Further, considering that each of the group members can act as a transmitter, all UEs 115 in the group should know the group size.

[0079] In some cases, such as in platooning where a group of vehicles travel together in a convoy, an application layer protocol (e.g., a V2X application layer) may form a sidelink multicast communication group, and negotiation may occur between the UEs 115 that are members of the group. In some cases, a group leader (such as a platoon leader in a platooning application) will know the size of the group and be able to assign a UE member identifier to each group member. The group leader may then provide sidelink multicast information for the sidelink group, which may include the group size and the group member identifier of each UE 115 that is a member, and the information may then be provided to the AS layer at each UE 115. This information may be used to identify the PSFCH resources at each UE 115.

[0080] For example, in a group including five UEs 115, the group leader may inform one group member of the group identifier (e.g., group ID), the group size (e.g., 5), and assign a member ID (e.g., UE member ID=3). Using this information, the V2X layer at the UE 115 may map the group ID to a destination layer 2 ID, which may be passed to the AS layer for operation. At the same time, when generating the source layer 2 ID, the UE 115 may reflect the UE member ID in a subset of the bits of the source layer 2 ID (e.g., in the last 3 bits). Additionally, the group size (e.g., 5) will be passed down to the AS layer. When the V2X layer configures the AS layer regarding the QoS flow for the V2X application, it will indicate that the QoS flow is for multicast and provide corresponding QoS parameters (e.g., sidelink QoS identifier (PQI) and the communication range of the sidelink transmission).

[0081] When the AS layer at the receiving UE 115 receives such information from the upper layer, the AS layer can operate accordingly. For example, if the UE 115 needs to perform transmission based on the QoS flow ID (PFI) and the corresponding QoS context, the destination layer 2ID and the source layer 2ID can be retrieved. In addition, the AS layer at the UE 115 can check the group size and determine whether to use a separate PSFCH resource for each UE 115 to provide confirmation feedback. In some cases, the group size threshold can be configured (for example, as part of the side link multicast configuration), where the group size at or below the threshold (for example, 19 group members) has a separate PSFCH resource, while the group size above the threshold uses a shared PSFCH resource. In the case of using a separate PSFCH resource for confirmation feedback, the AS layer at the UE 115 can derive the source layer 1ID from the source layer 2ID reflecting the member ID of the UE (for example, taking the last 8 bits of the layer 2ID), and include the source layer 1ID in the side link control information (SCI).

[0082] Additionally, for the UE 115 that is receiving a packet in the group, the group size and UE member ID information associated with the group can also be notified to the receiving UE 115 at the AS layer. Accordingly, when a packet is received, the UE 115 can use the group size and its own UE member ID to derive the PSFCH resource for providing confirmation feedback of the packet. For example, if the member ID of the receiving UE 115 is 5, and the member ID of the transmitting UE 115 is 3, the receiving UE 115 can use the group size to infer the member ID of the transmitting UE 115 (member ID = 3) (e.g., mod (layer 1 ID, group size)), and determine that it should use the PSFCH resource with an index of 4 (i.e., the receiving UE member ID-1, because the receiving UE member ID> the transmitting UE member ID). Therefore, in such a situation, the group size and UE member ID information provided by the application layer allows the use of separate feedback resources at each member UE 115. In situations where the number of UEs 115 in a group is relatively large and above a threshold, a common feedback resource may be used by multiple UEs in the group. In some cases, this operation may be inferred at each UE 115 by the group size provided in the SCI. In other cases, the type of feedback operation may be explicitly indicated in the SCI when the transmission is performed.

[0083] Figure 3 An example of a UE protocol stack 300 that supports a sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure is illustrated. In some examples, the UE protocol stack 300 can implement aspects of the wireless communication system 100 or 200. In this example, a first UE 115-d can communicate with a second UE 115-e in a sidelink multicast group. Each of the first UE 115-d and the second UE 115-e includes an application layer 305, an optional middleware layer 310, a layer 2 315, and a layer 1 320.

[0084] In some cases, layer 1 320 and layer 2 315 may be referred to as an AS layer. Layer 1 320 may include a physical layer that provides a physical transmission channel for over-the-air signals. Layer 2 315 may include, for example, a media access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer. The optional middleware layer 310 may include, for example, a group management middleware layer that can distribute side link multicast information to lower layers (e.g., layer 1 320 and layer 2 315). In other cases, the application layer 305 (e.g., a V2X application layer) may perform group management and distribute side link multicast information to lower layers. As described with reference to Figure 2 As discussed, in some cases, source and destination Layer 2 IDs and Layer 1 IDs may be determined by each UE 115 and used for multicast communications and for determining resources for acknowledging feedback transmissions.

[0085] Figure 4 An example of a process flow 400 for supporting sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure is illustrated. In some examples, the process flow 400 may implement aspects of the wireless communication system 100 or 200. The process flow 400 may be implemented by a first UE 115-f, a second UE 115-g, or any other example of a UE 115 or base station 105 as described herein. The following alternative examples may be implemented, in which some steps are performed in a different order than described or not performed at all. In some cases, each step may include additional features not mentioned below, or further steps may be added.

[0086] At 405, the first UE 115-f may determine the sidelink multicast parameters. In some cases, the first UE 115-f may be a group leader for the sidelink multicast communication (e.g., a queue leader in a V2X sidelink communication), and may identify several other UEs including the second UE 115-g as group members. In some examples, the UE 115-f may determine the member ID of the UE 115-f. In some cases, the first UE 115-f may determine the member ID of each UE 115 in the group as part of the sidelink multicast parameter determination. In addition, the first UE 115-f may determine the group ID associated with the sidelink multicast communication group. In some cases, the sidelink multicast parameters may be determined by the group management middleware layer, the application layer, or a combination thereof.

[0087] At 410, the first UE 115-f may determine a sidelink multicast feedback configuration. In some cases, the first UE 115-f may identify an acknowledgment feedback resource for providing sidelink multicast feedback. In some cases, the acknowledgment feedback resource may include separate resources for different UEs 115 of the sidelink multicast communication group. For example, the acknowledgment feedback resource may be configured as described in reference to FIG. Figure 2 The acknowledgment feedback resource configuration is determined as discussed.

[0088] At 415, the first UE 115-f may transmit sidelink multicast information to the second UE 115-g, which may include a group ID, a member ID of the second UE 115-g, a group size, and an optional feedback configuration indication (e.g., indicating shared or separate feedback resources). In some cases, the sidelink multicast information may be provided in an SCI transmitted to the second UE 115-g.

[0089] At 420, the first UE 115-f may determine a UE identity to provide to the lower layer (e.g., the AS layer). Similarly, at 425, the second UE 115-g may determine a UE identity to provide to the lower layer (e.g., the AS layer). In some cases, the UE identity may include a source layer 2 ID, a destination layer 2 ID, a layer 1 ID, or any combination thereof. For example, as described in reference to Figure 2 The UE identity(ies) is / are determined in question.

[0090] At 430, the first UE 115-f may transmit the sidelink communication to at least the second UE 115-g and one or more other UEs that may be included in the sidelink multicast communication group. At 435, the second UE 115-g may receive and decode the sidelink communication and generate acknowledgment feedback (e.g., a HARQ ACK / NACK indication).

[0091] At 440, the second UE 115-g may determine feedback resources to be used to transmit the acknowledgment feedback to the first UE 115-f. Figure 2 This determination of the acknowledgment feedback resources is performed as discussed.At 445, the second UE 115-g may transmit a feedback communication with the acknowledgment feedback to the first UE 115-f.

[0092] At 450, the first UE 115-f may determine whether to retransmit the sidelink communication based on the received feedback. In some cases, the first UE 115-f may determine to retransmit the sidelink communication based on receiving one or more NACKs from other UEs 115 of the group. Additionally or alternatively, the first UE 115-f may determine to retransmit the sidelink communication based on receiving acknowledgment feedback from less than all UEs 115 in the group (e.g., based on a group size of the sidelink multicast communication group).

[0093] Figure 5 A block diagram 500 of a device 505 supporting a sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure is shown. The device 505 may be an example of aspects of a UE 115 (e.g., a first UE device or a second UE) as described herein. The device 505 may include a receiver 510, a communication manager 515, and a transmitter 520. The device 505 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0094] The receiver 510 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sidelink multicast configurations for supporting feedback control, etc.). The information may be passed to other components of the device 505. The receiver 510 may be a reference Figure 8Examples of aspects of the described transceiver 820. The receiver 510 may utilize a single antenna or a collection of antennas.

[0095] The communication manager 515 can receive side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes multiple members, and the multiple members include at least a first UE and a second UE; determine, at the first UE, an identifier for communicating with the first side link group based on the side link multicast information; and communicate with the first side link group based on the determined identifier.

[0096] The communication manager 515 may also configure a first side link group for side link multicast communication, wherein the first side link group includes a plurality of members, the plurality of members including at least a first UE and a second UE; determine a member identity of the first UE; determine a feedback resource configuration for the side link group based on a group size of the first side link group and the determined identity of the first UE, wherein the feedback resource configuration includes a shared feedback resource used by the plurality of members or a separate feedback resource corresponding to each of the plurality of members; transmit side link multicast information indicating at least the feedback resource configuration to other members of the plurality of members of the first side link group; communicate with the first side link group based on the determined identity and the feedback resource configuration; and determine, at the first UE, an identity for communicating with the first side link group based on the side link multicast information. The communication manager 515 may be an example of aspects of the communication manager 810 described herein.

[0097] The communication manager 515 or its subcomponents may be implemented in hardware, in code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 515 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 designed to perform the functions described in the present disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0098] The communication manager 515 or its subcomponents may be physically located at various locations, including being distributed such that portions of 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 515 or its subcomponents may be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 515 or its subcomponents may 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.

[0099] The transmitter 520 may transmit signals generated by other components of the device 505. In some examples, the transmitter 520 may be co-located with the receiver 510 in a transceiver module. For example, the transmitter 520 may be a reference Figure 8 Examples of aspects of the described transceiver 820. The transmitter 520 may utilize a single antenna or a collection of antennas.

[0100] The communication manager 515 may be an example of a means for performing various aspects of the sidelink multicast configuration as described herein. The communication manager 515 or its subcomponents may be implemented in hardware (e.g., in a communication manager circuit system). The circuit system may include a processor, DSP, ASIC, 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.

[0101] In another implementation, the communication manager 515 or its subcomponents may be implemented in code executed by a processor (e.g., as communication management software or firmware), or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 515 or its subcomponents may be performed by a general purpose processor, DSP, ASIC, FPGA, or other programmable logic device.

[0102] In some examples, communications manager 515 may be configured to perform various operations (eg, receive, determine, transmit) using or otherwise in cooperation with receiver 510, transmitter 520, or both.

[0103] In some examples, the communication manager 515 may be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver 510 and transmitter 520 may 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.

[0104] The communication manager 515 as described may be implemented to achieve one or more potential advantages. One implementation may allow the device 505 to support feedback control for sidelink multicast communications. Thus, the device 505 may determine device identification and feedback resources, and may experience enhanced reliability and efficiency. In some examples, the device 505 may experience reduced power consumption and increased battery life, among other benefits.

[0105] Figure 6 A block diagram 600 of a device 605 supporting a sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure is shown. The device 605 may be an example of aspects of the device 505, or a UE 115 (e.g., a first UE or a second UE) as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 640. The device 605 may also include a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0106] The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sidelink multicast configuration to support feedback control, etc.). The information may be passed to other components of the device 605. The receiver 610 may be a reference Figure 8 Examples of aspects of the described transceiver 820. The receiver 610 may utilize a single antenna or a collection of antennas.

[0107] The communication manager 615 may be an example of aspects of the communication manager 515 as described herein. The communication manager 615 may include a sidelink configuration manager 620, an identification manager 625, a sidelink communication manager 630, and a feedback configuration manager 635. The communication manager 615 may be an example of aspects of the communication manager 810 described herein.

[0108] In some cases, the sidelink configuration manager 620 may receive sidelink multicast information of a first sidelink group from a second UE, the sidelink multicast information including a group size of the first sidelink group and a member identifier of the first UE in the first sidelink group, wherein the first sidelink group includes a plurality of members, the plurality of members including at least the first UE and the second UE. The identifier manager 625 may determine an identifier for communicating with the first sidelink group based on the sidelink multicast information at the first UE. The sidelink communication manager 630 may communicate with the first sidelink group based on the determined identifier.

[0109] In some cases, the side link configuration manager 620 may configure a first side link group for side link multicast communication, wherein the first side link group includes multiple members, and the multiple members include at least a first UE and a second UE. The feedback configuration manager 635 may determine a feedback resource configuration for the side link group based on the group size of the first side link group, wherein the feedback resource configuration includes a shared feedback resource used by multiple members or a separate feedback resource corresponding to each of the multiple members. The side link communication manager 630 may transmit side link multicast information indicating at least the feedback resource configuration to other members of the multiple members of the first side link group, and communicate with the first side link group based on the determined identifier and feedback resource configuration. The identifier manager 625 may determine an identifier for communicating with the first side link group based on the side link multicast information at the first UE.

[0110] The transmitter 640 may transmit signals generated by other components of the device 605. In some examples, the transmitter 640 may be co-located with the receiver 610 in a transceiver module. For example, the transmitter 640 may be a reference Figure 8 Examples of aspects of the described transceiver 820. The transmitter 640 may utilize a single antenna or a collection of antennas.

[0111] Figure 7 A block diagram 700 of a communication manager 705 supporting sidelink multicast configuration to support feedback control is shown in accordance with one or more aspects of the present disclosure. The communication manager 705 may be an example of aspects of the communication manager 515, the communication manager 615, or the communication manager 810 described herein. The communication manager 705 may include a sidelink configuration manager 710, an identification manager 715, a sidelink communication manager 720, an L2 ID manager 725, an L1 ID manager 730, a feedback configuration manager 735, a feedback determination manager 740, and a QoS flow manager 745. Each of these modules may communicate directly or indirectly with each other (e.g., via one or more buses).

[0112] The sidelink configuration manager 710 may receive sidelink multicast information of a first sidelink group from a second UE, the sidelink multicast information including a group size of the first sidelink group and a member identifier of the first UE in the first sidelink group, wherein the first sidelink group includes a plurality of members, the plurality of members including at least the first UE and the second UE. In some cases, the sidelink multicast information further includes a group identifier of the first sidelink group.

[0113] In some examples, the sidelink configuration manager 710 may configure a first sidelink group for sidelink multicast communication, wherein the first sidelink group includes a plurality of members, the plurality of members including at least a first UE and a second UE. In some cases, the sidelink multicast information is received at an application layer of the first UE or at a group management middleware layer of the first UE. In some cases, the sidelink multicast information further indicates a group identifier of the first sidelink group, a group size of the first sidelink group, and a corresponding member identifier within the first sidelink group of each of the plurality of members.

[0114] The identification manager 715 may determine, at the first UE, an identification for communicating with the first sidelink group based on the sidelink multicast information. In some examples, the identification manager 715 may determine a member identification of the first UE.

[0115] The sidelink communication manager 720 may communicate with the first sidelink group based on the determined identification.

[0116] In some examples, the sidelink communication manager 720 may transmit sidelink multicast information indicating at least the feedback resource configuration to other members of the plurality of members of the first sidelink group. In some examples, the sidelink communication manager 720 may communicate with the first sidelink group based on the determined identification and feedback resource configuration.

[0117] The feedback configuration manager 735 may determine a feedback resource configuration for the side link group based on the group size of the first side link group and the member identifier of the first UE, wherein the feedback resource configuration includes a common feedback resource used by multiple members or a separate feedback resource corresponding to each of the multiple members.

[0118] In some examples, the feedback configuration manager 735 may determine whether to provide acknowledgment feedback information to other members of the first side link group using a separate feedback resource by each of the members of the first side link group based on the group size of the first side link group.

[0119] In some cases, the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based on whether the number of members of the first side link group is higher than a threshold number of members. In some cases, when the number of members of the first side link group is at or below the threshold number of members, separate feedback resources are used to provide confirmation feedback information. In some cases, when the number of members of the first side link group exceeds the threshold number of members, shared resources are used to provide confirmation feedback information.

[0120] In some cases, the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based on pre-configuration of the first UE, control signaling received from another UE or a base station, or any combination thereof. In some cases, the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based on RRC signaling received at the first UE, SIB received at the first UE, MAC control elements received at the first UE, or any combination thereof. In some cases, the number of separate feedback resources corresponds to the number of members of the first side link group minus one.

[0121] The L2 ID manager 725 can manage the layer 2 ID of the UE. In some cases, the identification is a destination layer 2 identification, and the member identification of the first UE is included as a first bit subset of the source layer 2 identification. In some cases, the group identifier is mapped into a second bit subset of the destination layer 2 identification. In some cases, the number of bits of the first bit subset is determined based on the group size of the first side link group. In some cases, the identification is a source layer 2 identification, and the identification of the first UE is included as a first bit subset of the source layer 2 identification, and wherein the group identifier is mapped to a second bit subset of the destination layer 2 identification. In some cases, the number of bits of the first bit subset is determined based on the group size of the first side link group.

[0122] The L1 ID manager 730 may determine a layer 1 identity based on a source layer 2 identity, wherein the layer 1 identity is indicated in a physical layer control information transmission to the first side link group. In some cases, the layer 1 identity corresponds to a subset of the source layer 2 identity indicating a group identifier of the first side link group and a member identity of the first UE within the first side link group.

[0123] The feedback determination manager 740 may determine a set of feedback resources for transmitting acknowledgment feedback information to one or more members of the first side link group based at least in part on a group size of the first side link group and a member identity of the first UE within the first side link group.

[0124] In some examples, the feedback determination manager 740 may receive the first multicast communication from the second UE. In some examples, the feedback determination manager 740 may determine an acknowledgment feedback for the first multicast communication. In some examples, the feedback determination manager 740 may transmit an acknowledgment feedback for the first multicast communication to the second UE using a feedback resource set.

[0125] In some examples, feedback determination manager 740 may transmit the multicast communication to other members of the plurality of members of the first side link group. In some examples, feedback determination manager 740 may determine to retransmit the multicast communication based on acknowledgement feedback from at least one member of the plurality of members of the first side link group.

[0126] In some examples, the feedback determination manager 740 may determine that at least one of the plurality of members of the first side link group provided a negative acknowledgement, determine that acknowledgement feedback from at least one of the plurality of members of the first side link group was not received at the first UE, or any combination thereof. In some examples, the feedback determination manager 740 may transmit a multicast communication to other members of the plurality of members of the first side link group. In some examples, the feedback determination manager 740 may monitor acknowledgement feedback from other members of the plurality of members of the first side link group based on the feedback resource configuration.

[0127] The QoS flow manager 745 may configure an access layer at the first UE for a QoS flow for multicast communication associated with a layer 2 identifier, and wherein the access layer determines the QoS flow identifier and the QoS context, and derives a layer 1 identifier for the QoS flow.

[0128] Figure 8 A diagram of a system 800 including a device 805 supporting a sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure is shown. The device 805 may be an example of a device 505, a device 605, or a UE 115 as described herein or a component thereof. The device 805 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 810, an I / O controller 815, a transceiver 820, an antenna 825, a memory 830, and a processor 840. These components may be in electronic communication via one or more buses (e.g., a bus 845).

[0129] The communication manager 810 may receive side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE within the first side link group, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determine, at the first UE, an identifier for communicating with the first side link group based on the side link multicast information; and communicate with the first side link group based on the determined identifier.

[0130] The communication manager 810 may also configure a first side link group for side link multicast communication, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determine a member identifier of the first UE; determine a feedback resource configuration for the side link group based on the group size of the first side link group and the determined member identifier of the first UE, wherein the feedback resource configuration includes a common feedback resource used by the multiple members or a separate feedback resource corresponding to each of the multiple members; transmit side link multicast information indicating at least the feedback resource configuration to other members of the multiple members of the first side link group; communicate with the first side link group based on the determined identifier and the feedback resource configuration; and determine, at the first UE, an identifier for communicating with the first side link group based on the side link multicast information.

[0131] I / O controller 815 can manage input and output signals of device 805. I / O controller 815 can also manage peripheral devices that are not integrated into device 805. In some cases, I / O controller 815 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 815 can utilize an operating system, such as Or another known operating system. In other cases, I / O controller 815 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 815 may be implemented as part of a processor. In some cases, a user may interact with device 805 via I / O controller 815 or via hardware components controlled by I / O controller 815.

[0132] The transceiver 820 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 820 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 820 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0133] In some cases, a wireless device may include a single antenna 825. However, in some cases, the device may have more than one antenna 825, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0134] The memory 830 may include random access memory (RAM) and read-only memory (ROM). The memory 830 may store computer-readable, computer-executable code 835 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, the memory 830 may include, among other things, a basic input / output system (BIOS), which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0135] The processor 840 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, the processor 840 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 840. The processor 840 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 830) to cause the device 805 to perform various functions (e.g., supporting a side link multicast configuration to support a function or task of feedback control).

[0136] The code 835 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 835 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 835 may not be directly executed by the processor 840, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0137] Fig. 9 A flow chart illustrating a method 900 for supporting sidelink multicast configuration to support feedback control according to one or more 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 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the following functions.

[0138] At 905, the UE may receive side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least the first UE and the second UE. The operations of 905 may be performed according to the methods described herein. In some examples, aspects of the operations of 905 may be performed as described with reference to Figures 5 to 8The described sidelink configuration manager is used to perform.

[0139] At 910, the UE may determine an identifier for communicating with the first side link group based on the side link multicast information. 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 with reference to Figures 5 to 8 The described identity manager is implemented.

[0140] At 915, the UE may communicate with the first side link group based on the determined identification. 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 with reference to Figures 5 to 8 The sidelink communication manager described is used to perform.

[0141] Fig.10 1 is a flow chart illustrating a method 1000 for supporting sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure. The operations of the method 1000 may be implemented by a UE 115 or a component thereof as described herein. For example, the operations of the method 1000 may be implemented by a UE 115 or a component thereof as described herein. Figures 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the following functions.

[0142] At 1005, the UE may receive side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least the first UE and the second UE. The operations of 1005 may be performed according to the methods described herein. In some examples, aspects of the operations of 1005 may be performed as described with reference to Figures 5 to 8 The described sidelink configuration manager is used to perform.

[0143] At 1010, the UE may determine an identifier for communicating with the first side link group based on the side link multicast information. The operations of 1010 may be performed according to the methods described herein. In some examples, aspects of the operations of 1010 may be performed as described with reference to Figures 5 to 8 The described identity manager is implemented.

[0144] At 1015, the UE may communicate with the first side link group based on the determined identification. The operations of 1015 may be performed according to the methods described herein. In some examples, aspects of the operations of 1015 may be as described with reference to Figures 5 to 8 The sidelink communication manager described is used to perform.

[0145] At 1020, the UE may determine, based on the group size of the first side link group, whether to use a separate feedback resource by each of the plurality of members of the first side link group for providing confirmation feedback information to other members of the plurality of members of the first side link group. The operations of 1020 may be performed according to the methods described herein. In some examples, aspects of the operations of 1020 may be performed as described with reference to Figures 5 to 8 The described feedback configuration manager is implemented.

[0146] Fig.11 1 is a flow chart illustrating a method 1100 for supporting sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure. 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 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the following functions.

[0147] At 1105, the UE may receive side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least the first UE and the second UE. The operations of 1105 may be performed according to the methods described herein. In some examples, aspects of the operations of 1105 may be performed as described with reference to Figures 5 to 8 The described sidelink configuration manager is used to perform.

[0148] At 1110, the UE may determine an identifier for communicating with the first side link group based on the side link multicast information. 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 with reference to Figures 5 to 8 The described identity manager is implemented.

[0149] At 1115, the UE may determine a set of feedback resources for transmitting acknowledgement feedback information to one or more members of the first side link group based at least in part on the group size of the first side link group and the member identity of the first UE within the first side link group. 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 with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0150] At 1120, the UE may receive a first multicast communication from a second UE. The operations of 1120 may be performed according to the methods described herein. In some examples, aspects of the operations of 1120 may be performed as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0151] At 1125, the UE may determine an acknowledgement feedback for the first multicast communication. The operations of 1125 may be performed according to the methods described herein. In some examples, aspects of the operations of 1125 may be as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0152] At 1130, the UE may transmit an acknowledgement feedback for the first multicast communication to the second UE using the feedback resource set. The operations of 1130 may be performed according to the methods described herein. In some examples, aspects of the operations of 1130 may be as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0153] Fig.12 A flow chart illustrating a method 1200 for supporting sidelink multicast configuration to support feedback control according to one or more 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 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the following functions.

[0154] At 1205, the UE may receive side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group includes a plurality of members, the plurality of members including at least the first UE and 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 with reference to Figures 5 to 8 The described sidelink configuration manager is used to perform.

[0155] At 1210, the UE may determine an identifier for communicating with the first side link group based on the side link multicast information. 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 with reference to Figures 5 to 8 The described identity manager is implemented.

[0156] At 1215, the UE may transmit the multicast communication to other members of the plurality of members of the first side link group. The operations of 1215 may be performed according to the methods described herein. In some examples, aspects of the operations of 1215 may be performed as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0157] At 1220, the UE may monitor for acknowledgment feedback from other members of the plurality of members of the first side link group. The operations of 1220 may be performed according to the methods described herein. In some examples, aspects of the operations of 1220 may be performed as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0158] At 1225, the UE may determine to retransmit the multicast communication based on the acknowledgement feedback from at least one of the plurality of members of the first side link group. The operations of 1225 may be performed according to the methods described herein. In some examples, aspects of the operations of 1225 may be performed as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0159] Fig.13 1 is a flow chart illustrating a method 1300 for supporting sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure. 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 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the following functions.

[0160] At 1305, the UE may configure a first side link group for side link multicast communication, wherein the first side link group includes a plurality of members, the plurality of members including at least a first UE and a 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 with reference to Figures 5 to 8 The described sidelink configuration manager is used to perform.

[0161] At 1310, the UE may determine a member identity of the first UE. 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 with reference to Figures 5 to 8 The described identity manager is implemented.

[0162] At 1315, the UE may determine a feedback resource configuration for the side link group based on the group size of the first side link group and the determined member identity of the first UE, wherein the feedback resource configuration includes a common feedback resource used by multiple members or a separate feedback resource corresponding to each of the multiple members. The operations of 1315 may be performed according to the methods described herein. In some examples, aspects of the operations of 1315 may be performed as described with reference to Figures 5 to 8 The described feedback configuration manager is implemented.

[0163] At 1320, the UE may transmit side link multicast information indicating at least the feedback resource configuration to other members of the plurality of members of the first side link group. The operations of 1320 may be performed according to the methods described herein. In some examples, aspects of the operations of 1320 may be performed as described with reference to Figures 5 to 8 The sidelink communication manager described is used to perform.

[0164] At 1325, the UE may determine an identifier for communicating with the first side link group based on the side link multicast information. The operations of 1325 may be performed according to the methods described herein. In some examples, aspects of the operations of 1325 may be performed as described with reference to Figures 5 to 8 The described identity manager is implemented.

[0165] At 1330, the UE may communicate with the first side link group based on the determined identification and the feedback resource configuration. The operations of 1330 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1330 may be performed as described with reference to Figures 5 to 8 The sidelink communication manager described is used to perform.

[0166] Fig.14 1 is a flow chart illustrating a method 1400 for supporting sidelink multicast configuration to support feedback control according to one or more aspects of the present disclosure. 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 5 to 8 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the following functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the following functions.

[0167] At 1405, the UE may configure a first side link group for side link multicast communication, wherein the first side link group includes a plurality of members, the plurality of members including at least a first UE and a 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 with reference to Figures 5 to 8 The described sidelink configuration manager is used to perform.

[0168] At 1410, the UE may determine a member identity of the first UE. 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 with reference to Figures 5 to 8 The described identity manager is implemented.

[0169] At 1415, the UE may determine a feedback resource configuration for the side link group based on the group size of the first side link group, wherein the feedback resource configuration includes a common feedback resource used by multiple members or a separate feedback resource corresponding to each of the multiple members. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed as described with reference to Figures 5 to 8 The described feedback configuration manager is implemented.

[0170] At 1420, the UE may transmit side link multicast information indicating at least the feedback resource configuration to other members of the plurality of members of the first side link group. 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 with reference to Figures 5 to 8 The sidelink communication manager described is used to perform.

[0171] At 1425, the UE may determine an identifier for communicating with the first side link group based on the side link multicast information. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be performed as described with reference to Figures 5 to 8 The described identity manager is implemented.

[0172] At 1430, the UE may transmit a multicast communication to other members of the plurality of members of the first side link group. The operations of 1430 may be performed according to the methods described herein. In some examples, aspects of the operations of 1430 may be performed as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0173] At 1435, the UE may monitor the acknowledgment feedback from other members of the plurality of members of the first side link group based on the feedback resource configuration. The operations of 1435 may be performed according to the methods described herein. In some examples, aspects of the operations of 1435 may be performed as described with reference to Figures 5 to 8 The feedback determination manager described herein is executed. In some cases, when the number of the plurality of members of the first side link group is at or below a threshold number of members, the separate feedback resources are used to provide confirmation feedback information. In some cases, when the number of the plurality of members of the first side link group exceeds the threshold number of members, the shared feedback resources are used to provide confirmation feedback information.

[0174] At 1440, the UE may determine to retransmit the multicast communication based on the acknowledgement feedback from at least one of the plurality of members of the first side link group. The operations of 1440 may be performed according to the methods described herein. In some examples, aspects of the operations of 1440 may be performed as described with reference to Figures 5 to 8 The described feedback determination manager is performed.

[0175] The following provides an overview of various examples of the present disclosure:

[0176] Example 1: A method for performing wireless communications at a first UE, comprising: receiving side link multicast information of a first side link group from a second UE, the side link multicast information including a group size of the first side link group and a member identifier of the first UE within the first side link group, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determining, at the first UE, an identifier for communicating with the first side link group based at least in part on the side link multicast information; and communicating with the first side link group based at least in part on the determined identifier.

[0177] Example 2: The method of Example 1 further includes: determining whether to use a separate feedback resource by each of the multiple members of the first side link group for providing confirmation feedback information to other members of the multiple members of the first side link group based at least in part on the group size of the first side link group.

[0178] Example 3: The method of Example 2, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide acknowledgment feedback information based at least in part on whether the number of the plurality of members of the first side link group is above a threshold number of members.

[0179] Example 4: A method as in Example 2, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based at least in part on pre-configuration of the first UE, control signaling received from another UE or a base station, or any combination thereof.

[0180] Example 5: A method as in Example 2, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based at least in part on RRC signaling received at the first UE, SIB received at the first UE, MAC control elements received at the first UE, or any combination thereof.

[0181] Example 6: A method as in any one of Examples 1 to 5, wherein the identifier is a source layer 2 identifier, and the member identifier of the first UE is included as a first bit subset of the source layer 2 identifier.

[0182] Example 7: The method of any of Examples 1 to 6, wherein the sidelink multicast information further includes a group identifier of the first sidelink group.

[0183] Example 8: The method of Example 7, wherein the group identifier is mapped to a second subset of bits of the destination layer 2 identification.

[0184] Example 9: A method as in any one of Examples 6 to 8, further comprising: determining a layer 1 identifier based at least in part on a source layer 2 identifier, wherein the layer 1 identifier is indicated in a physical layer control information transmission to the first side link group.

[0185] Example 10: A method as in Example 9, wherein the layer 1 identifier corresponds to a subset of the source layer 2 identifier indicating the member identifiers of the first UE within the first side link group.

[0186] Example 11: The method of any of Examples 6 to 8, wherein the number of bits of the first subset of bits is determined based at least in part on a group size of the first side link group.

[0187] Example 12: The method of any one of Examples 1 to 11, further comprising: determining a set of feedback resources for transmitting acknowledgement feedback information to one or more members of the first side link group based at least in part on a group size of the first side link group and a member identity of the first UE within the first side link group. .

[0188] Example 13: The method of Example 12 further includes: receiving the first multicast communication from the second UE; determining an acknowledgment feedback for the first multicast communication; and transmitting the acknowledgment feedback for the first multicast communication to the second UE using the feedback resource set.

[0189] Example 14: The method of any one of Examples 1 to 13 further includes: transmitting multicast communications to other members of the multiple members of the first side link group; monitoring confirmation feedback from other members of the multiple members of the first side link group; and determining to retransmit the multicast communications based at least in part on confirmation feedback from at least one member of the multiple members of the first side link group.

[0190] Example 15: A method as in Example 14, wherein determining to retransmit further includes: determining that at least one of the multiple members of the first side link group provides a negative acknowledgment, determining that acknowledgment feedback from at least one of the multiple members of the first side link group is not received at the first UE, or any combination thereof.

[0191] Example 16: A method as in any one of Examples 1 to 15, further comprising: configuring an access layer at the first UE for a QoS flow for multicast communication associated with a layer 2 identifier, and wherein the access layer layer determines the QoS flow identifier and the QoS context, and derives the layer 2 identifier of the QoS flow.

[0192] Example 17: The method of any one of Examples 1 to 16, wherein the sidelink multicast information is received at an application layer of the first UE or at a group management middleware layer of the first UE.

[0193] Example 18: A method for performing wireless communications at a first UE, comprising: configuring a first side link group for side link multicast communications, wherein the first side link group includes multiple members, the multiple members including at least a first UE and a second UE; determining a member identifier of the first UE; determining a feedback resource configuration for the side link group based at least in part on a group size of the first side link group and the determined member identifier of the first UE; transmitting side link multicast information indicating at least the feedback resource configuration to other members of the multiple members of the first side link group; determining, at the first UE, an identifier for communicating with the first side link group based at least in part on the side link multicast information; and communicating with the first side link group based at least in part on the determined identifier and the feedback resource configuration.

[0194] Example 19: The method of Example 18, wherein the feedback resource configuration includes a common feedback resource used by the plurality of members or a separate feedback resource corresponding to each of the plurality of members.

[0195] Example 20: A method as in Example 19, wherein when the number of multiple members of the first side link group is at or below a threshold number of members, a separate feedback resource is used to provide confirmation feedback information; and when the number of multiple members of the first side link group exceeds the threshold number of members, a common application resource is used to provide confirmation feedback information.

[0196] Example 21: A method as in either Example 19 or 20, further comprising: transmitting multicast communications to other members of the plurality of members of the first side link group; monitoring confirmation feedback from other members of the plurality of members of the first side link group based at least in part on feedback resource configuration; and determining to retransmit the multicast communications based at least in part on confirmation feedback from at least one member of the plurality of members of the first side link group.

[0197] Example 22: A method as in Example 21, wherein determining to retransmit further includes: determining that at least one of the multiple members of the first side link group provides a negative acknowledgment, determining that acknowledgment feedback from at least one of the multiple members of the first side link group is not received at the first UE, or any combination thereof.

[0198] Example 23: A method as in any one of Examples 18 to 22, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based at least in part on pre-configuration of the first UE, control signaling received from another UE or base station, or any combination thereof.

[0199] Example 24: A method as in any of Examples 18 to 22, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide confirmation feedback information based at least in part on RRC signaling received at the first UE, SIB received at the first UE, MAC control elements received at the first UE, or any combination thereof.

[0200] Example 25: The method of any one of Examples 18 to 24, wherein the number of separate feedback resources corresponds to the number of the plurality of members of the first side link group minus one.

[0201] Example 26: A method as in any one of Examples 18 to 25, wherein the side link multicast information further indicates a group identifier of the first side link group, a group size of the first side link group, and a corresponding member identification of each of the plurality of members within the first side link group.

[0202] Example 27: A method as in Example 26, wherein the identifier is a source layer 2 identifier, and the identifier of the first UE is included as a first subset of bits of the source layer 2 identifier, and wherein the group identifier is mapped to a second subset of bits of the destination layer 2 identifier.

[0203] Example 28: The method of Example 27, further comprising: determining a layer 1 identifier based at least in part on a source layer 2 identifier, wherein the layer 1 identifier is indicated in a physical layer control information transmission to the first side link group.

[0204] Example 29: The method of Example 28, wherein the layer 1 identifier corresponds to a subset of the source layer 2 identifier.

[0205] Example 30: An apparatus for wireless communication, comprising a processor and a memory coupled to the processor, the processor and the memory configured to perform the method of any one of Examples 1 to 17.

[0206] Example 31: An apparatus for wireless communication, comprising a processor and a memory coupled to the processor, the processor and the memory configured to perform the method of any one of Examples 18 to 29.

[0207] Example 32: An apparatus for wireless communication, comprising at least one means for performing the method of any one of Examples 1 to 17.

[0208] Example 33: An apparatus for wireless communication, comprising at least one means for performing the method of any one of Examples 18 to 29.

[0209] Example 34: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of any one of Examples 1 to 17.

[0210] Example 35: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of any of Examples 18 to 29.

[0211] It should be noted that the methods described herein describe possible implementations, and that the various operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0212] The technology described herein can be used in various wireless communication systems, such as CDMA, time division multiple access (TDMA), frequency division multiple access (FDMA), 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). CDMA2000 covers IS-2000, IS-95 and IS-856 standards. IS-2000 versions are generally referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is generally referred to as CDMA2000 1xEV-DO, High Rate 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).

[0213] 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 may be used for systems and radio technologies mentioned herein as well as for 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 also be applicable to applications other than LTE, LTE-A, LTE-A Pro, or NR applications.

[0214] A macro cell may cover a relatively large geographic area (e.g., an area of ​​several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions to a network provider. A small cell may be associated with a lower power base station (compared to a macro cell), 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. A pico cell, for example, may cover a smaller geographic area and may allow unrestricted access by UEs with service subscriptions to a network provider. A femto cell may also cover a smaller geographic area (e.g., a residence) and may provide restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG), UEs of users in the residence, 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 (eg, two, three, four, etc.) cells and may also support communication using one or more component carriers.

[0215] The wireless communication systems described herein may support synchronous or asynchronous operation. For synchronous operation, each base station may have similar frame timing, and transmissions from different base stations may be roughly aligned in time. For asynchronous operation, each base station 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.

[0216] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0217] 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 an 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).

[0218] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0219] Computer-readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer-readable medium can 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 device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer or general or special-purpose processor any other non-transient medium.Similarly, any connection is also properly referred to as computer-readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then the coaxial cable, optical fiber cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are just included in the definition of medium. Disk and disc as used herein include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, 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.

[0220] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Similarly, as used herein, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an exemplary step described as "based on condition A" may 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."

[0221] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number, or other subsequent reference numbers.

[0222] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that may be implemented or that fall within the scope of the claims. The term "exemplary" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques 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.

[0223] 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 universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a first user equipment (UE), comprising: receiving side link multicast information of a first side link group from a second UE, the side link multicast information comprising a group size of the first side link group and a member identifier of the first UE in the first side link group, wherein the first side link group comprises a plurality of members, the plurality of members comprising at least the first UE and the second UE; determining, at the first UE, an identification for communicating with the first sidelink group based at least in part on the sidelink multicast information; as well as Communicating with the first sidelink group based at least in part on the determined identification.

2. The method of claim 1, further comprising: Whether to provide acknowledgment feedback information by each of the plurality of members of the first side link group to other members of the plurality of members of the first side link group using separate feedback resources is determined based at least in part on the group size of the first side link group.

3. The method of claim 2, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide the acknowledgment feedback information based at least in part on whether the number of the plurality of members of the first side link group is higher than a threshold number of members.

4. The method of claim 2, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide the acknowledgment feedback information based at least in part on a preconfiguration of the first UE, control signaling received from another UE or a base station, or any combination thereof.

5. The method of claim 2, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide the confirmation feedback information based at least in part on radio resource control (RRC) signaling received at the first UE, a system information block (SIB) received at the first UE, a medium access control (MAC) control element received at the first UE, or any combination thereof.

6. The method of claim 1, wherein the identifier is a source layer 2 identifier, and a member identifier of the first UE is included as a first bit subset of the source layer 2 identifier.

7. The method of claim 6, wherein the sidelink multicast information further comprises a group identifier of the first sidelink group.

8. The method of claim 7, wherein the group identifier is mapped into a second subset of bits of a destination layer 2 identification.

9. The method of claim 6, further comprising: A layer 1 identity is determined based at least in part on the source layer 2 identity, wherein the layer 1 identity is indicated in a physical layer control information transmission to the first sidelink group.

10. The method of claim 9, wherein the layer 1 identifier corresponds to a subset of the source layer 2 identifier indicating the membership identifiers of the first UE in the first sidelink group.

11. The method of claim 6, wherein the number of bits of the first subset of bits is determined based at least in part on the group size of the first sidelink group.

12. The method of claim 1, further comprising: A set of feedback resources for transmitting acknowledgment feedback information to one or more members of the first side link group is determined based at least in part on the group size of the first side link group and a member identification of the first UE within the first side link group.

13. The method of claim 12, further comprising: receiving a first multicast communication from the second UE; determining a receipt feedback for the first multicast communication; as well as The acknowledgement feedback for the first multicast communication is transmitted to the second UE using the set of feedback resources.

14. The method of claim 1, further comprising: transmitting a multicast communication to other members of the plurality of members of the first sidelink group; monitoring acknowledgement feedback from other members of the plurality of members of the first sidelink group; and A determination is made to retransmit the multicast communication based at least in part on the acknowledgment feedback from at least one of the plurality of members of the first sidelink group.

15. The method of claim 14, wherein determining to retransmit further comprises: Determining that at least one of the plurality of members of the first sidelink group provided a negative acknowledgment, determining that acknowledgment feedback from at least one of the plurality of members of the first sidelink group was not received at the first UE, or any combination thereof.

16. The method of claim 1, further comprising: An access plane layer is configured at the first UE for a quality of service (QoS) flow for multicast communication associated with a layer 2 identifier, and wherein the access plane layer determines a QoS flow identifier and a QoS context, and derives a layer 1 identifier for the QoS flow.

17. The method of claim 1, wherein the sidelink multicast information is received at an application layer of the first UE or at a group management middleware layer of the first UE.

18. A method for wireless communication at a first user equipment (UE), comprising: configuring a first sidelink group for sidelink multicast communication, wherein the first sidelink group includes a plurality of members, the plurality of members including at least the first UE and a second UE; Determining a member identifier of the first UE; determining a feedback resource configuration for the sidelink group based at least in part on a group size of the first sidelink group and the determined member identity of the first UE; transmitting sidelink multicast information indicating at least the feedback resource configuration to other members of the plurality of members of the first sidelink group; determining, at the first UE, an identification for communicating with the first sidelink group based at least in part on the sidelink multicast information; as well as Communicating with the first sidelink group based at least in part on the determined identification and the feedback resource configuration.

19. The method of claim 18, wherein: The feedback resource configuration includes a common feedback resource used by the plurality of members or an individual feedback resource corresponding to each of the plurality of members.

20. The method of claim 19, wherein: When the number of the plurality of members of the first side link group is at or below a threshold number of members, a separate feedback resource is used to provide acknowledgement feedback information; and When the number of the plurality of members of the first side link group exceeds a threshold number of members, the common resource is used to provide acknowledgement feedback information.

21. The method of claim 20, further comprising: transmitting a multicast communication to other members of the plurality of members of the first sidelink group; monitoring acknowledgement feedback from other members of the plurality of members of the first sidelink group based at least in part on the feedback resource configuration; and A determination is made to retransmit the multicast communication based at least in part on acknowledgement feedback from at least one of the plurality of members of the first sidelink group.

22. The method of claim 21, wherein determining to retransmit further comprises: Determining that at least one of the plurality of members of the first sidelink group provided a negative acknowledgment, determining that acknowledgment feedback from at least one of the plurality of members of the first sidelink group was not received at the first UE, or any combination thereof.

23. The method of claim 18, wherein the first UE determines whether to use the separate feedback resource or the shared feedback resource to provide the acknowledgment feedback information based at least in part on a preconfiguration of the first UE, control signaling received from another UE or a base station, or any combination thereof.

24. The method of claim 18, wherein the first UE determines whether to use separate feedback resources or shared feedback resources to provide the confirmation feedback information based at least in part on radio resource control (RRC) signaling received at the first UE, a system information block (SIB) received at the first UE, a medium access control (MAC) control element received at the first UE, or any combination thereof.

25. The method of claim 18, wherein the number of separate feedback resources corresponds to the number of the plurality of members of the first sidelink group minus one.

26. The method of claim 18, wherein the sidelink multicast information further indicates a group identifier of the first sidelink group, a group size of the first sidelink group, and a corresponding member identification of each of the plurality of members within the first sidelink group.

27. An apparatus for wireless communication at a first user equipment (UE), comprising: means for receiving sidelink multicast information of a first sidelink group from a second UE, the sidelink multicast information comprising a group size of the first sidelink group and a member identifier of the first UE in the first sidelink group, wherein the first sidelink group comprises a plurality of members, the plurality of members comprising at least the first UE and the second UE; for determining, at the first UE, an identification for communicating with the first sidelink group based at least in part on the sidelink multicast information; and means for communicating with said first sidelink group based at least in part on said determined identification; as well as Means for communicating with the first sidelink group based at least in part on the determined identification.

28. The apparatus of claim 27, further comprising: Means for determining whether to provide, by each of the plurality of members of the first side link group using separate feedback resources, acknowledgment feedback information to other members of the plurality of members of the first side link group based at least in part on the group size of the first side link group.

29. An apparatus for wireless communication at a first user equipment (UE), comprising: means for configuring a first sidelink group for sidelink multicast communications, wherein the first sidelink group comprises a plurality of members, the plurality of members comprising at least the first UE and a second UE; means for determining a member identity for the first UE; means for determining a feedback resource configuration for the sidelink group based at least in part on a group size of the first sidelink group and the determined member identity of the first UE; means for transmitting sidelink multicast information indicating at least the feedback resource configuration to other members of the plurality of members of the first sidelink group; means for determining, at the first UE, an identification for communicating with the first sidelink group based at least in part on the sidelink multicast information; as well as Means for communicating with the first sidelink group based at least in part on the determined identification and the feedback resource configuration.

30. The apparatus of claim 29, wherein: The feedback resource configuration includes a common feedback resource used by the plurality of members or an individual feedback resource corresponding to each of the plurality of members.

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