Semi-persistent scheduling (SPS) for sidelink groupcast

Abstract

Systems and methods are described for implementing semi-persistent scheduling (SPS) transmissions of periodic messages via one or more sidelinks. SPS for sidelink groupcast can be activated and / or deactivated using SPS control signaling for the SPS for the sidelink groupcast. The SPS control signaling used to activate / deactivate the SPS for the sidelink groupcast can include an SPS indicator (e.g., conveyed at least in part via a SCI format 0-1 message), an activation / deactivation indicator (e.g., conveyed at least in part via a SCI format 0-1 message and / or a SCI format 0-2 message), and / or a configuration index (e.g., conveyed at least in part via a SCI format 0-1 message and / or a SCI format 0-2 message). Other aspects and features are also claimed and described.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Patent Application No. 17 / 323,504, filed May 18, 2021, entitled “SEMI-PERSISTENT SCHEDULING (SPS) FOR SIDELINK GROUPCAST,” and U.S. Provisional Patent Application No. 63 / 049,902, filed July 9, 2020, entitled “SEMI-PERSISTENT SCHEDULING (SPS) FOR SIDELINK GROUPCAST,” the disclosures of which are expressly incorporated herein by reference in their entirety. Technical Field

[0003] Various aspects of this disclosure generally relate to wireless communication systems, and more particularly to user equipment (UE) sidelink communication. Certain embodiments of the techniques discussed below can implement and provide semi-persistent scheduling (SPS) for sidelink multicast.

[0004] introduction

[0005] Wireless communication networks are widely deployed to provide various communication services, such as voice, video, packet data, message sending and receiving, broadcasting, and so on. These wireless networks can be multiple-access networks capable of supporting multiple users by sharing available network resources. Typically, such multiple-access networks support communication for multiple users by sharing available network resources.

[0006] A wireless communication network may include several base stations or B-nodes capable of supporting communication between several user equipments (UEs). UEs may communicate with base stations via downlinks and uplinks. A downlink (or forward link) refers to the communication link from the base station to the UE, while an uplink (or reverse link) refers to the communication link from the UE to the base station.

[0007] The base station can transmit data and control information to the UE on the downlink and / or receive data and control information from the UE on the uplink. On the downlink, transmissions from the base station may encounter interference from neighboring base stations or other radio frequency (RF) transmitters. On the uplink, transmissions from the UE may encounter interference from uplink transmissions from other UEs communicating with neighboring base stations or from other RF transmitters. This interference can degrade the performance of both the downlink and uplink.

[0008] In many scenarios, the base station-to-UE link does not fully utilize the potential capabilities of the baseband UE hardware. For example, the UE form factor may limit the UE's RF capabilities, and thus limit the maximum actual data rate. Approaches used to address such RF limitations have included techniques for relaying user traffic. For instance, the Integrated Access and Backhaul (IAB) configuration provides a Layer 2 (i.e., data link layer) communication solution where both backhaul and access are controlled by the network (e.g., the base station). The Consumer Premises Equipment (CPE) configuration provides a Layer 3 (i.e., network layer) communication solution where backhaul is controlled by the network (e.g., the base station) and access is controlled by the CPE (e.g., the UE).

[0009] Overview

[0010] The following outlines some aspects of this disclosure to provide a basic understanding of the techniques discussed. This overview is not an exhaustive summary of all conceived features of this disclosure, and is neither intended to identify all key or decisive elements of all aspects of this disclosure, nor to define the scope of any or all aspects of this disclosure. Its sole purpose is to provide, in an overview form, some concepts of one or more aspects of this disclosure as a prelude to the more detailed description that follows.

[0011] In one aspect of this disclosure, a method for wireless communication is provided. The method may include: transmitting a multicast indicator for sidelink multicast by a first user equipment (UE), the multicast indicator indicating that a corresponding sidelink transmission is multicast to multiple UEs. The method may further include: transmitting semi-persistent scheduling (SPS) control signaling for the sidelink multicast by the first UE, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0012] In an additional aspect of this disclosure, an apparatus configured for wireless communication is provided. The apparatus may include: means for transmitting, by a first UE, a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission is multicast to multiple UEs. The apparatus may further include: means for transmitting, by the first UE, SPS control signaling for the sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0013] In an additional aspect of this disclosure, a non-transient computer-readable medium having program code for wireless communication recorded thereon is provided. The program code may include: code for transmitting, by a first UE, a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission is multicast to multiple UEs. The program code may also include: code for transmitting, by the first UE, SPS control signaling for the sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0014] In an additional aspect of this disclosure, an apparatus configured for wireless communication is provided. The apparatus includes at least one processor and memory coupled to the processor. The processor may be configured to cause the apparatus to: transmit a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission performed by a first UE is multicast to multiple UEs. The processor may also be configured to cause the apparatus to: transmit SPS control signaling for the sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0015] According to various aspects of this disclosure, the aforementioned systems, methods, and apparatuses may be implemented in conjunction with one or more additional features (such as the features described below individually or in combination). For example, the aforementioned systems, methods, and apparatuses may include: an SPS indicator being transmitted at least partially via one or more fields of a Sidelink Control Information (SCI) format 0-1 message. The aforementioned systems, methods, and apparatuses may include: a Cyclic Redundancy Code (CRC) included in the fields of the SCI format 0-1 message being scrambled using an SPS Radio Network Temporary Identifier (RNTI) used to provide the SPS indicator. The aforementioned systems, methods, and apparatuses may include: a shared sidelink SPS RNTI (SL-SPS-RNTI) shared by all UEs communicating on a sidelink with the first UE. The aforementioned systems, methods, and apparatuses may include: a shared SL-SPS-RNTI indicating that the SCI format 0-1 message and the corresponding SCI format 0-2 message contain SPS information for sidelink multicast. The aforementioned systems, methods, and apparatus may include: an SPS RNTI that is a group-specific RNTI (SL-SPS-Group-RNTI) for a group of multicast receiving UEs including the plurality of UEs. The aforementioned systems, methods, and apparatus may include: when the group indicated by the SL-SPS-Group-RNTI matches the group indicated in the SCI format 0-2 message corresponding to the SCI format 0-1 message, making the message destination group identifier and zone identifier in the corresponding SCI format 0-2 message available for purposes other than the destination group identifier and zone identifier. The aforementioned systems, methods, and apparatus may include: a field in the SCI format 0-1 message defined to indicate the presence of SPS information in the SCI format 0-1 message and the corresponding SCI format 0-2 message providing an SPS indicator. The aforementioned systems, methods, and apparatus may include: an activation status indicator indicating the activation or deactivation of the SPS for sidelink multicast. The aforementioned systems, methods, and apparatus may include: an activation status indicator being transmitted at least partially via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof. The aforementioned systems, methods, and apparatus may include: providing an activation status indicator via a combination of the contents of at least one field of an SCI format 0-1 message and at least one field of an SCI format 0-2 message. The aforementioned systems, methods, and apparatus may include: the content of at least one field of an SCI format 0-1 message including the content of an indicator group SPS, and the content of at least one field of an SCI format 0-2 message including a new data indicator.The aforementioned systems, methods, and apparatus may include: when the content of at least one field of an SCI format 0-1 message indicates a group SPS, the content of at least one field of an SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for sidelink multicast is feasible, an activation status indicator indicates activation of the SPS for sidelink multicast; and when the content of at least one field of an SCI format 0-1 message indicates a group SPS, the content of at least one field of an SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for sidelink multicast is set to all 0s, an activation status indicator indicates deactivation of the SPS for sidelink multicast. The aforementioned systems, methods, and apparatus may include: a field in an SCI format 0-1 message defined for indicating the activation state of the SPS for sidelink multicast, or a field in an SCI format 0-2 message defined for indicating the activation state, providing an activation status indicator. The aforementioned systems, methods, and apparatus may include: a configuration index transmitted at least partially via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof. The aforementioned systems, methods, and apparatus may include: a configuration index provided by a combination of the contents of a field of an SCI format 0-1 message indicating the SPS and a field of an Automatic Repeat Request (HARQ) procedure identifier specifying the index value. The aforementioned systems, methods, and apparatus may include: a field of an SCI format 0-1 message defined for indicating an index value of the configuration index, or a field of an SCI format 0-2 message defined for indicating the index value. The aforementioned systems, methods, and apparatus may include: a configuration index providing an index for one or more parameters in a parameter set, the parameter set including one or more of the following: an SPS radio network temporary identifier (RNTI), the periodicity of sidelink multicast, or the maximum number of times a transport block (TB) for sidelink multicast can be transmitted. The aforementioned system, method, and apparatus may include: transmitting a first SCI format 0-1 message for sidelink multicast by a first UE; transmitting a first SCI format 0-2 message for sidelink multicast by the first UE, wherein SPS control signaling for sidelink multicast transmitted by the first UE is included in the SCI format 0-1 message, the SCI format 0-2 message, or a combination thereof; and transmitting Physical Sidelink Shared Channel (PSSCH) multicast data for sidelink multicast. The aforementioned system, method, and apparatus may include: an activation status indicator indicating activation of SPS for sidelink multicast; monitoring feedback messages from each of a plurality of UEs; and determining that activation of SPS for sidelink multicast is incomplete if no feedback message has been received from each of the plurality of UEs, or determining that activation of SPS for sidelink multicast is complete if a feedback message has been received from each of the plurality of UEs.The aforementioned systems, methods, and apparatus may include: when it is determined that the activation of the SPS for the sidelink multicast is not complete, subsequent PSSCH multicast data transmission for the sidelink multicast is accompanied by a first SCI format 0-1 message and a second SCI format 0-2 message. The aforementioned systems, methods, and apparatus may also include: when it is determined that the activation of the SPS for the sidelink multicast is complete, subsequent PSSCH multicast data transmission for the sidelink multicast is not accompanied by an SCI format 0-1 message, an SCI format 0-2 message, or both. The aforementioned systems, methods, and apparatus may include: sidelink resources for the sidelink multicast are scheduled by a base station communicating with a first UE; determining that the content of the SCI format 0-1 message and the content of the SCI format 0-2 message associated with an instance of subsequent PSSCH multicast data transmission are equivalent to the content of one of the corresponding first SCI format 0-1 message and the first SCI format 0-2 message; and instances where the first UE transmits subsequent PSSCH multicast data transmission for the sidelink multicast without being accompanied by an SCI format 0-1 message and an SCI format 0-2 message. The aforementioned system, method, and apparatus may include: sidelink resources for sidelink multicast being scheduled by a first UE; determining that the content of SCI format 0-1 messages and SCI format 0-2 messages associated with an instance of subsequent PSSCH multicast data transmission are equivalent to the content of one of the corresponding first SCI format 0-1 messages and the first SCI format 0-2 messages; and instances in which the first UE transmits subsequent PSSCH multicast data transmission for sidelink multicast accompanied by SCI format 0-1 messages but not accompanied by SCI format 0-2 messages. The aforementioned system, method, and apparatus may include: an activation status indicator indicating the activation of the SPS for sidelink multicast; a first UE transmitting a second SCI format 0-1 message for sidelink multicast; the first UE transmitting a second SCI format 0-2 message for sidelink multicast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or both include updated content relative to the first SCI format 0-1 message, the first SCI format 0-2 message, or both, for reactivating the SPS for sidelink multicast using a different SPS configuration; and transmitting subsequent PSSCH multicast data for sidelink multicast. The aforementioned system, method, and apparatus may also include: the first UE transmitting a second SCI format 0-1 message for sidelink multicast; and the first UE transmitting a second SCI format 0-2 message for sidelink multicast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or a combination thereof, provides an activation status indicator indicating the deactivation of the SPS for sidelink multicast. The aforementioned system, method, and apparatus may include: a first UE determining to retransmit a multicast TB for sidelink multicast based on a negative acknowledgment (NACK) received from a UE among the plurality of UEs for PSSCH multicast data transmission for sidelink multicast.The aforementioned system, method, and apparatus may include: a first UE determining that a multicast TB for sidelink multicast needs to be retransmitted based on the failure to receive an acknowledgment (ACK) for PSSCH multicast data transmission for sidelink multicast from one of the plurality of UEs. The aforementioned system, method, and apparatus may include: allocating resources by a first UE for retransmitting a multicast TB for sidelink multicast; retransmitting the multicast TB by the first UE, wherein the same HARQ procedure identifier of the original transmission for the multicast TB is used to retransmit the multicast TB, and wherein retransmitting the TB includes: transmitting a second SCI format 0-1 message for sidelink multicast by the first UE; transmitting a second SCI format 0-2 message for sidelink multicast by the first UE, wherein the second SCI format 0-1 message and the second SCI format 0-2 message carry SPS control signaling for sidelink multicast; and retransmitting PSSCH multicast data for sidelink multicast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or both include one or more fields indicating that the PSSCH multicast data is retransmitted data for sidelink multicast.

[0016] In one aspect of this disclosure, a method for wireless communication is provided. The method may include: receiving, by one of a plurality of UEs in communication with a first UE, a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission performed by the first UE is multicast to the plurality of UEs. The method may further include: receiving, by the UE among the plurality of UEs, SPS control signaling for sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0017] In an additional aspect of this disclosure, an apparatus configured for wireless communication is provided. The apparatus may include: means for receiving, by one of a plurality of UEs in communication with a first UE, a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission performed by the first UE is multicast to the plurality of UEs. The apparatus may further include: means for receiving, by the UE among the plurality of UEs, SPS control signaling for sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0018] In an additional aspect of this disclosure, a non-transient computer-readable medium having program code for wireless communication recorded thereon is provided. The program code may include: code for a UE among a plurality of UEs in communication with a first UE to receive a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission performed by the first UE is multicast to the plurality of UEs. The program code may further include: code for the UE among the plurality of UEs to receive SPS control signaling for sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0019] In an additional aspect of this disclosure, an apparatus configured for wireless communication is provided. The apparatus includes at least one processor and a memory coupled to the processor. The processor may be configured to cause the apparatus to: receive a multicast indicator for sidelink multicast from a first UE to a plurality of UEs, the multicast indicator indicating that a corresponding sidelink transmission performed by the first UE is multicast to the plurality of UEs. The processor may also be configured to cause the apparatus to: receive SPS control signaling for the sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0020] According to various aspects of this disclosure, the aforementioned systems, methods, and apparatuses may be implemented in conjunction with one or more additional features (such as the features described below individually or in combination). For example, the aforementioned systems, methods, and apparatuses may include: an SPS indicator being received at least partially via one or more fields of a Side Link Control Information (SCI) format 0-1 message. The aforementioned systems, methods, and apparatuses may include: a CRC included in the fields of the SCI format 0-1 message being scrambled using an SPS RNTI that provides the SPS indicator. The aforementioned systems, methods, and apparatuses may include: a shared SL-SPS-RNTI shared by all UEs in sidelink communication with the first UE. The aforementioned systems, methods, and apparatuses may include: a shared SL-SPS-RNTI indicating that the SCI format 0-1 message and the corresponding SCI format 0-2 message contain SPS information for sidelink multicast. The aforementioned systems, methods, and apparatuses may include: an SPS-RNTI for a group of multicast receiving UEs including the plurality of UEs. The aforementioned systems, methods, and apparatus may include: when the group indicated by SL-SPS-group-RNTI matches the group indicated in the SCI-format 0-2 message corresponding to the SCI-format 0-1 message, the message destination group identifier and zone identifier in the corresponding SCI-format 0-2 message are used for purposes other than the destination group identifier and zone identifier. The aforementioned systems, methods, and apparatus may include: a field in the SCI-format 0-1 message defined to indicate the existence of SPS information in the SCI-format 0-1 message and the corresponding SCI-format 0-2 message providing an SPS indicator. The aforementioned systems, methods, and apparatus may include: an activation status indicator indicating the activation or deactivation of SPS for cross-link multicast. The aforementioned systems, methods, and apparatus may include: the activation status indicator being received at least partially via one or more fields of the SCI-format 0-1 message, one or more fields of the SCI-format 0-2 message, or a combination thereof. The aforementioned systems, methods, and apparatus may include: a combination of the contents of at least one field of an SCI format 0-1 message and at least one field of an SCI format 0-2 message providing an activation status indicator. The aforementioned systems, methods, and apparatus may include: the contents of at least one field of an SCI format 0-1 message including the contents of an indicator group SPS, and the contents of at least one field of an SCI format 0-2 message including a new data indicator.The aforementioned systems, methods, and apparatus may include: when the content of at least one field of an SCI format 0-1 message indicates a group SPS, the content of at least one field of an SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for sidelink multicast is feasible, an activation status indicator indicates activation of the SPS for sidelink multicast; and when the content of at least one field of an SCI format 0-1 message indicates a group SPS, the content of at least one field of an SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for sidelink multicast is set to all 0s, an activation status indicator indicates deactivation of the SPS for sidelink multicast. The aforementioned systems, methods, and apparatus may include: fields in an SCI format 0-1 message defined for indicating the activation state of the SPS for sidelink multicast, or fields in an SCI format 0-2 message defined for indicating the activation state, providing an activation status indicator. The aforementioned systems, methods, and apparatus may include: a configuration index received at least partially via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof. The aforementioned systems, methods, and apparatus may include: providing a configuration index by a combination of the contents of an SCI format 0-1 message indicating a group SPS and a HARQ procedure identifier field specifying an index value. The aforementioned systems, methods, and apparatus may include: providing a configuration index by a field of an SCI format 0-1 message defined for indicating an index value of the configuration index, or a field of an SCI format 0-2 message defined for indicating such an index value. The aforementioned systems, methods, and apparatus may include: providing a configuration index to an index of one or more parameters in a parameter set, the parameter set including one or more of the following: SPS RNTI, periodicity of sidelink multicast, or the maximum number of times a TB can be transmitted for sidelink multicast. The aforementioned system, method, and apparatus may include: receiving a first SCI format 0-1 message for sidelink multicast by one of the plurality of UEs; receiving a first SCI format 0-2 message for sidelink multicast by one of the plurality of UEs; determining whether the first SCI format 0-1 message and the first SCI format 0-2 message correspond to sidelink transmissions for sidelink multicast to the plurality of UEs; analyzing the first SCI format 0-1 message, the first SCI format 0-2 message, or both, to obtain an activation status indicator, the activation status indicator indicating activation or deactivation of SPS for sidelink multicast. The aforementioned system, method, and apparatus may include: the activation status indicator indicating activation of SPS for sidelink multicast, and decoding PSSCH multicast data for sidelink multicast by one of the plurality of UEs. The aforementioned system, method, and apparatus may include: transmitting an ACK or NACK for decoding PSSCH multicast data by one of the plurality of UEs, regardless of the NACK-only option for decoding PSSCH multicast data.The aforementioned system, method, and apparatus may include: storing configuration parameters for SPS, the content of a first SCI format 0-1 message, and the content of a first SCI format 0-2 message by one of the plurality of UEs; receiving PSSCH multicast data according to the SPS by one of the plurality of UEs; and transmitting ACK or NACK for the PSSCH multicast data by one of the plurality of UEs according to the SPS configuration parameters and the content of the first SCI format 0-1 message and the first SCI format 0-2 message stored by one of the plurality of UEs. The aforementioned system, method, and apparatus may include: determining, at least partially based on a configuration index, that the SPS of the cross-link multicast is new; and storing the periodicity procedure of the SPS in an SPS periodicity procedure database by one of the plurality of UEs. The aforementioned system, method, and apparatus may include: determining, at least partially based on a configuration index, that the SPS of the cross-link multicast is a reactivation of the SPS; and updating the periodicity procedure of the SPS in the SPS periodicity procedure database by one of the plurality of UEs. The aforementioned system, method, and apparatus may include: an activation state indicator indicating the deactivation of SPS for sidelink multicast, and the cancellation of a periodic procedure for SPS by one of the plurality of UEs, wherein the UE among the plurality of UEs stops periodic monitoring of the PSSCH for searching for sidelink multicast data. The aforementioned system, method, and apparatus may also include: the value of the activation state indicator indicating the activation of SPS for sidelink multicast; the UE among the plurality of UEs receiving a second SCI format 0-1 message for sidelink multicast; the UE among the plurality of UEs receiving a second SCI format 0-2 message for sidelink multicast; the UE among the plurality of UEs determining, at least in part, that the periodic procedure for SPS remains valid based on the failure of the second SCI format 0-1 message and the second SCI format 0-2 message to include SPS information for sidelink multicast; and monitoring the PSSCH according to the periodic procedure for SPS to search for sidelink multicast data.

[0021] Other aspects, features, and embodiments will become apparent to those skilled in the art after reading the following description of specific exemplary embodiments in conjunction with the accompanying drawings. Although features may be discussed hereinafter with reference to certain aspects and drawings, all embodiments may include one or more of the advantageous features discussed herein. In other words, although one or more aspects may be discussed having certain advantageous features, one or more such features may also be used depending on various aspects. Similarly, although exemplary aspects may be discussed hereinafter as aspects of an apparatus, system, or method, exemplary aspects may be implemented in various apparatuses, systems, and methods. Brief description of the attached diagram

[0023] A further understanding of the nature and advantages of this disclosure can be obtained by referring to the following figures. In the figures, similar components or features may have the same reference numerals. Furthermore, components of the same type may be distinguished by a dash following the reference numeral and a second reference numeral used to differentiate between similar components. If only the first reference numeral is used in the description, the description may be applied to any of the similar components having the same first reference numeral regardless of the second reference numeral.

[0024] Figure 1 This is a block diagram illustrating details of an example of a wireless communication system according to some embodiments of the present disclosure.

[0025] Figure 2 This is a block diagram that conceptually illustrates an example design of a base station and a UE configured according to some embodiments of this disclosure.

[0026] Figure 3 This is an example of an integrated access and backhaul (IAB) communication configuration based on some embodiments of this disclosure.

[0027] Figure 4 This is an example consumer device (CPE) communication configuration according to some embodiments of this disclosure.

[0028] Figure 5A and 5B Examples of sidelink resource granting according to vehicle-to-everything (V2X) transmission mode 1 are shown in some embodiments of this disclosure.

[0029] Figure 6A and 6B Examples of sidelink resource granting according to V2X transport mode 2 are shown in some embodiments of this disclosure.

[0030] Figure 7 This is an example CPE communication configuration based on some embodiments of this disclosure.

[0031] Figure 8 and 9 This is an example flowchart of operations for semi-persistent scheduling (SPS) for crosslink multicast according to some embodiments of this disclosure.

[0032] Figure 10 This is a block diagram conceptually illustrating the design of a UE configured for side-link multicast operation according to some embodiments of this disclosure.

[0033] Detailed description

[0034] The detailed description that follows, taken in conjunction with the accompanying drawings, is intended to describe various configurations and is not intended to limit the scope of this disclosure. Rather, this detailed description includes specific details to provide a thorough understanding of the subject matter of the invention. It will be apparent to those skilled in the art that these specific details are not required in every situation, and in some instances, well-known structures and components are shown in block diagram form for clarity of expression.

[0035] This disclosure generally relates to providing or participating in licensed shared access between two or more wireless devices in one or more wireless communication systems (also referred to as wireless communication networks). In various implementations, technologies and apparatus can be used in wireless communication networks such as Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, Single Carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, fifth-generation (5G) or new radio (NR) networks (sometimes referred to as "5G NR" networks / systems / devices), and other communication networks. As described herein, the terms "network" and "system" may be used interchangeably.

[0036] CDMA networks can implement radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. UTRA includes Wideband CDMA (W-CDMA) and Low Chip Rate (LCR). CDMA2000 covers the IS-2000, IS-95, and IS-856 standards.

[0037] TDMA networks can implement radio technologies such as the Global System for Mobile Communications (GSM). The 3rd Generation Partnership Project (3GPP) defines the standard for the Radio Access Network (RAN) (also referred to as GERAN) for GSM EDGE (Enhanced Data Rate GSM Evolution). GERAN is the radio component of GSM / EDGE along with the network that connects base stations (e.g., Ater and Abis interfaces) to base station controllers (A interface, etc.). The radio access network represents the component of the GSM network through which telephone calls and packet data are routed from the Public Switched Telephone Network (PSTN) and the Internet to the subscriber's handset (also called user terminal or user equipment (UE)) and from the subscriber's handset to the PSTN and the Internet. A mobile phone operator's network may include one or more GERANs, which may be coupled to the Universal Terrestrial Radio Access Network (UTRAN) in the case of UMTS / GSM networks. Additionally, the operator's network may also include one or more LTE networks, and / or one or more other networks. Different network types may use different Radio Access Technologies (RATs) and Radio Access Networks (RANs).

[0038] OFDMA networks can implement radio technologies such as Evolved UTRA (E-UTRA), IEEE 802.11, IEEE 802.16, IEEE 802.20, and flash-OFDM. UTRA, E-UTRA, and GSM are part of the Universal Mobile Telecommunications System (UMTS). Specifically, Long Term Evolution (LTE) is a UMTS version using E-UTRA. UTRA, E-UTRA, GSM, UMTS, and LTE are described in documents from an organization called the 3rd Generation Partnership Project (3GPP), while cdma2000 is described in documents from an organization called 3rd Generation Partnership Project 2 (3GPP2). These various radio technologies and standards are known or under development. For example, 3GPP is a collaboration between various telecommunications association groups that aims to define globally applicable third-generation (3G) mobile phone specifications. 3GPP Long Term Evolution (LTE) is a 3GPP project aimed at improving the Universal Mobile Telecommunications System (UMTS) mobile phone standard. 3GPP defines specifications for next-generation mobile networks, mobile systems, and mobile devices. This disclosure may describe certain aspects with reference to LTE, 4G, or 5G NR technologies; however, this description is not intended to be limited to any particular technology or application, and one or more aspects described with reference to one technology may be understood to be applicable to another technology. In fact, one or more aspects of this disclosure relate to shared access to radio spectrum between networks using different radio access technologies or radio air interfaces.

[0039] 5G networks envision diverse deployments, diverse spectrum, and diverse services and devices that can be achieved using a unified air interface based on OFDM. To achieve these goals, in addition to developing new radio technologies for 5G NR networks, further enhancements to LTE and LTE-A are also considered. 5G NR will be able to scale to provide coverage for: (1) ultra-high density (e.g., approximately 1 M nodes / km) 2 (1) A massive Internet of Things (IoT) with ultra-low complexity (e.g., approximately tens of bits per second), ultra-low energy consumption (e.g., approximately 10+ years of battery life), and deep coverage capable of reaching challenging locations; (2) A massive Internet of Things (IoT) with robust security (to protect sensitive personal, financial, or confidential information), ultra-high reliability (e.g., approximately 99.9999% reliability), ultra-low latency (e.g., approximately 1 millisecond (ms)), and mission-critical control for users with a wide range of mobility or lack of mobility; and (3) Enhanced mobile broadband, including extremely high capacity (e.g., approximately 10 Tbps / km). 2 Extreme data rates (e.g., multi-Gbps rates, 100+Mbps user experience rates), and deep insights with advanced discovery and optimization.

[0040] 5G NR devices, networks, and systems can utilize optimized OFDM-based waveform characteristics. These characteristics can include: scalable parameter design and transmission time intervals (TTI); a shared, flexible framework for efficiently multiplexing services and features using dynamic, low-latency Time Division Duplex (TDD) / Frequency Division Duplex (FDD) designs; and advanced radio technologies such as massive MIMO, robust millimeter-wave (mmWave) transmission, advanced channel coding, and device-centric mobility. The scalability of parameter design in 5G NR (and the scaling of subcarrier spacing) can efficiently address the operation of diverse services across diverse spectrum and deployments. For example, in various outdoor and macro coverage deployments implemented with FDD / TDD below 3 GHz, subcarrier spacing can occur at 15 kHz over bandwidths such as 1, 5, 10, and 20 MHz. For other various outdoor and small-cell coverage deployments with TDD above 3 GHz, subcarrier spacing can occur at 30 kHz over an 80 / 100 MHz bandwidth. For various other indoor broadband implementations, by using TDD in the unlicensed portion of the 5 GHz band, the subcarrier spacing can occur at 60 kHz over a 160 MHz bandwidth. Finally, for various deployments transmitting mmWave components under TDD at 28 GHz, the subcarrier spacing can occur at 120 kHz over a 500 MHz bandwidth.

[0041] 5G NR's scalable parameter design enables scalable TTIs to meet various latency and Quality of Service (QoS) requirements. For example, shorter TTIs can be used for low latency and high reliability, while longer TTIs can be used for higher spectral efficiency. Efficient multiplexing of long and short TTIs allows transmissions to begin at symbol boundaries. 5G NR also envisions a self-contained integrated subframe design that incorporates uplink / downlink scheduling information, data, and acknowledgments within the same subframe. Self-contained integrated subframes support communication in unlicensed or contention-based shared spectrum and support adaptive uplink / downlink that can be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet current traffic needs.

[0042] For clarity, aspects of the devices and technologies may be described below with reference to example 5G NR implementations or in a 5G-centric manner, and 5G terminology may be used in various sections of the following description as illustrative examples; however, this description is not intended to be limited to 5G applications.

[0043] Furthermore, it should be understood that in operation, wireless communication networks adapted according to the concepts herein can be operated using any combination of licensed or unlicensed spectrum, depending on load and availability. Accordingly, it will be apparent to those skilled in the art that the systems, apparatuses, and methods described herein can be applied to other communication systems and applications different from the specific examples provided.

[0044] While aspects are described herein by way of example, those skilled in the art will understand that additional implementations and use cases can arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and package arrangements. For example, embodiments and / or devices may arise via integrated chip embodiments and / or other devices based on non-modular components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / shopping devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specific to particular use cases or applications, broad applicability of the described innovations is possible. Implementations can range from chip-level or modular components to non-modular, non-chip-level implementations, and further to aggregated, distributed, or OEM devices or systems incorporating one or more of the described aspects. In some practical contexts, devices incorporating the described aspects and features may also necessarily include additional components and features for implementing and practicing the claimed and described embodiments. The innovations described in this paper are intended to be implemented in a wide variety of ways, including both large and small devices of different sizes, shapes and configurations, chip-level components, multi-component systems (e.g., RF chains, communication interfaces, processors), distributed deployments, end-user devices, and so on.

[0045] Figure 1 This is a block diagram illustrating the details of an example wireless communication system. The wireless communication system may include a wireless network 100. Wireless network 100 may, for example, include a 5G wireless network. As those skilled in the art will appreciate, Figure 1 The components appearing in this network likely have corresponding parts in other network deployments (including, for example, cellular network deployments and non-cellular network deployments (e.g., device-to-device, peer-to-peer, or self-organizing network deployments, etc.)).

[0046] Figure 1The wireless network 100 described herein includes several base stations 105 and other network entities. A base station can be a station communicating with a UE and may also be referred to as an evolved B-node (eNB), a next-generation eNB (gNB), an access point, etc. Each base station 105 can provide communication coverage for a specific geographic area. In 3GPP, the term "cell" can refer to such a specific geographic coverage area of ​​a base station and / or a base station subsystem serving that coverage area, depending on the context in which the term is used. In the implementation of the wireless network 100 herein, base stations 105 may be associated with the same operator or different operators (e.g., the wireless network 100 may include multiple operator wireless networks). Additionally, in the implementation of the wireless network 100 herein, base stations 105 may use one or more frequencies (e.g., licensed spectrum, unlicensed spectrum, or one or more bands of a combination thereof) from the same frequencies as adjacent cells to provide wireless communication. In some examples, an individual base station 105 or UE 115 may be operated by more than one network operating entity. In some other examples, each base station 105 and UE 115 may be operated by a single network operating entity.

[0047] Base stations can provide communication coverage for macrocells or small cells (such as picocells or femtocells), and / or other types of cells. Macrocells typically cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access by UEs with service subscriptions to a network provider. Small cells (such as picocells) typically cover a relatively small geographic area and allow unrestricted access by UEs with service subscriptions to a network provider. Small cells (such as femtocells) also typically cover a relatively small geographic area (e.g., a residential area) and, in addition to unrestricted access, allow restricted access by UEs associated with that femtocell (e.g., UEs in a closed subscriber group (CSG), UEs of users in that residence, etc.). Base stations used for macrocells may be referred to as macro base stations. Base stations for small cells may be referred to as small cell base stations, pico base stations, femtocells, or home base stations. Figure 1 In the example shown, base stations 105d and 105e are conventional macro base stations, while base stations 105a-105c are macro base stations enabled with one of 3D, full-dimensional (FD), or massive MIMO enabled. Base stations 105a-105c utilize their higher-dimensional MIMO capabilities to increase coverage and capacity using 3D beamforming in both elevation and azimuth beamforming. Base station 105f is a small cell base station, which can be a home node or a portable access point. A base station can support one or more (e.g., two, three, four, etc.) cells.

[0048] Wireless Network 100 can support synchronous or asynchronous operation. For synchronous operation, each base station can have similar frame timing, and transmissions from different base stations can be roughly aligned in time. For asynchronous operation, each base station can have different frame timing, and transmissions from different base stations can be misaligned in time. In some scenarios, the network can be implemented or configured to handle dynamic switching between synchronous and asynchronous operation.

[0049] UE 115 is distributed across wireless network 100, and each UE can be either stationary or mobile. It should be understood that although mobile devices are generally referred to as User Equipment (UE) in standards and specifications issued by 3GPP, such devices may also be referred to by those skilled in the art as mobile station (MS), subscriber station, consumer equipment (CPE), mobile unit, subscriber unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile subscriber station, access terminal (AT), mobile terminal, radio terminal, remote terminal, handheld device, terminal, user agent, mobile client, client, gaming device, augmented reality device, vehicle component / module, or any other suitable term. Within this document, a “mobile” device or UE does not necessarily have mobility capabilities and may be stationary. Some non-limiting examples of mobile devices may include implementations of one or more of the various UEs 115, including mobile stations, cellular phones, smartphones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, laptops, personal computers (PCs), laptops, netbooks, smartbooks, tablets, personal digital assistants (PDAs), set-top boxes, and streaming content devices. Mobile devices can also be “Internet of Things” (IoT) or “Internet of Everything” (IoE) devices, such as automobiles or other transportation vehicles, satellite radios, Global Positioning System (GPS) devices, logistics controllers, drones, multi-rotor aircraft, quadcopters, smart energy or security devices, solar panels or solar arrays, urban lighting, water supply or other infrastructure; industrial automation and enterprise equipment; consumer and wearable devices, such as glasses, wearable cameras, smartwatches, health or fitness trackers, mammalian implantable devices, posture tracking devices, medical devices, digital audio players (e.g., MP3 players), cameras, game consoles, etc.; and digital home or smart home devices, such as home audio, video and multimedia equipment, appliances, sensors, vending machines, smart lighting, home security systems, smart meters, etc. In one aspect, a UE can be a device that includes a Universal Integrated Circuit Card (UICC). In another aspect, a UE can be a device that does not include a UICC. In some aspects, a UE that does not include a UICC can also be referred to as an IoE device. Figure 1The UEs 115a-115d described in the text are examples of mobile smartphone-type devices accessing the wireless network 100. The UE can also be a machine specifically configured for connected communications (including machine-type communication (MTC), enhanced MTC (eMTC), narrowband IoT (NB-IoT), etc.). Figure 1 The UE 115e-115k described in the text is an example of various machines configured for accessing communications on the wireless network 100.

[0050] Mobile devices (such as UE 115) can communicate with any type of base station (whether macro base station, pico base station, femto base station, relay, etc.). Figure 1 In this context, a communication link (represented as a lightning bolt) indicates radio transmissions between the UE and a serving base station (a serving base station is a base station designated to serve the UE on the downlink and / or uplink), or desired transmissions between base stations, and backhaul transmissions between base stations. In some scenarios, the UE may operate as a base station or other network node. Backhaul communication between base stations of the wireless network 100 can occur using wired and / or wireless communication links.

[0051] In the operation of wireless network 100, base stations 105a-105c use 3D beamforming and coordinated spatial technologies (such as Coordinated Multipoint (CoMP) or multi-connectivity) to serve UEs 115a and 115b. Macro base station 105d performs backhaul communication with base stations 105a-105c and small cell base station 105f. Macro base station 105d also transmits multicast services subscribed to and received by UEs 115c and 115d. Such multicast services may include mobile television or streaming video, or may include other services for providing community information (such as weather emergencies or alerts, such as Amber Alerts or Grey Alerts).

[0052] Each implemented wireless network 100 supports mission-critical communication with highly reliable and redundant links for mission-critical equipment such as UE 115e, which is a drone. Redundant communication links with UE 115e include those from macro base stations 105d and 105e, and small cell base station 105f. Other machine-type devices (such as UE 115f (thermometer), UE 115g (smart meter), and UE 115h (wearable device)) can communicate directly with base stations (such as small cell base station 105f and macro base station 105e) via wireless network 100, or in a multi-hop configuration via wireless network 100 by communicating with another user equipment relaying its information to the network (e.g., UE 115f relays temperature measurement information to smart meter UE 115g, which is then reported to the network via small cell base station 105f). Wireless network 100 can also provide additional network efficiency through dynamic, low-latency TDD / FDD communication, such as in vehicle-to-vehicle (V2V) mesh networks between UEs 115i-115k communicating with macro base station 105e.

[0053] Figure 2 A block diagram illustrating a conceptual design of base station 105 and UE 115 is shown. Base station 105 and UE 115 can be... Figure 1 Any one of the base stations and one of the UEs. For restricted association scenarios (as mentioned above), base station 105 can be... Figure 1 In the small cell base station 105f, UE 115 can be UE 115c or 115d operating within the service area of ​​base station 105f. To access small cell base station 105f, UE 115 will be included in the list of accessible UEs of small cell base station 105f. Base station 105 can also be some other type of base station. Figure 2 As shown, base station 105 may be equipped with antennas 234a to 234t, and UE 115 may be equipped with antennas 252a to 252r for facilitating wireless communication.

[0054] At base station 105, transmit processor 220 can receive data from data source 212 and control information from controller / processor 240. The control information can be used for Physical Broadcast Channel (PBCH), Physical Control Format Indicator Channel (PCFICH), Physical Hybrid ARQ (Automatic Repeat Request) Indicator Channel (PHICH), Physical Downlink Control Channel (PDCCH), Enhanced Physical Downlink Control Channel (EPDCCH), MTC Physical Downlink Control Channel (MPDCCH), etc. Data can be used for PDSCH, etc. Additionally, transmit processor 220 can process (e.g., encode and map symbol) data and control information to obtain data symbols and control symbols respectively. Transmit processor 220 can also generate reference symbols, for example, for primary synchronization signal (PSS) and secondary synchronization signal (SSS), and reference signals that vary depending on the cell. The transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, and / or reference symbols where applicable, and can provide the output symbol stream to modulators (MODs) 232a to 232t. For example, spatial processing performed on data symbols, control symbols, or reference symbols may include precoding. Each modulator 232 can process its respective output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 232 can additionally or alternatively process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The downlink signal from modulators 232a to 232t can be transmitted via antennas 234a to 234t, respectively.

[0055] At UE 115, antennas 252a to 252r can receive downlink signals from base station 105 and can respectively provide the received signals to demodulators (DEMODs) 254a to 254r. Each demodulator 254 can condition (e.g., filter, amplify, downconvert, and digitize) its respective received signal to obtain an input sample. Each demodulator 254 can further process the input sample (e.g., for OFDM, etc.) to obtain received symbols. MIMO detector 256 can obtain the received symbols from demodulators 254a to 254r, perform MIMO detection on these received symbols where applicable, and provide detected symbols. Receiver processor 258 can process (e.g., demodulate, deinterleave, and decode) these detected symbols, provide the decoded data to UE 115 to data sink 260, and provide the decoded control information to controller / processor 280.

[0056] On the uplink, at UE 115, transmit processor 264 can receive and process data from data source 262 (e.g., data for the Physical Uplink Shared Channel (PUSCH)) and control information from controller / processor 280 (e.g., control information for the Physical Uplink Control Channel (PUCCH)). Additionally, transmit processor 264 can also generate reference symbols for reference signals. Symbols from transmit processor 264 can be pre-encoded by TX MIMO processor 266, further processed by modulators 254a to 254r (e.g., for SC-FDM, etc.), and transmitted to base station 105, where applicable. At base station 105, uplink signals from UE 115 can be received by antenna 234, processed by demodulator 232, detected by MIMO detector 236, and further processed by receive processor 238 to obtain decoded data and control information transmitted by UE 115. Processor 238 can provide decoded data to data trap 239 and decoded control information to controller / processor 240.

[0057] Controllers / processors 240 and 280 can respectively direct operations at base station 105 and UE 115. Controllers / processors 240 and / or other processors and modules at base station 105 and / or controllers / processors 280 and / or other processors and modules at UE 115 can perform or direct the execution of various processes used in the techniques described herein, such as performing or directing... Figure 8 and Figure 9 The execution and / or other processes used in the techniques described herein are as explained herein. Memory 242 and 282 may store data and program code for base station 105 and UE 115, respectively. Scheduler 244 may schedule the UE for data transmission on downlink and / or uplink.

[0058] Wireless communication systems operated by different network operating entities (e.g., network operators) can share spectrum. In some instances, one network operating entity may be configured to use an entire designated shared spectrum for at least one time period, after which another network operating entity uses the same entire designated shared spectrum for a different time period. Thus, in order to allow network operating entities to use the entire designated shared spectrum and to mitigate interference communications between different network operating entities, specific resources (e.g., time) can be allocated and distributed to different network operating entities for specific types of communication.

[0059] For example, specific time resources can be allocated to a network operating entity, reserved for its exclusive use of the entire shared spectrum for communication. Additional time resources can also be allocated to a network operating entity, giving it priority over other network operating entities for communication within the shared spectrum. These time resources, preferentially allocated to the network operating entity, can be utilized by other network operating entities on a wait-and-see basis if the prioritized entity does not utilize them. Additional time resources can be allocated to any network operator for use on a wait-and-see basis.

[0060] Access to shared spectrum and arbitration of time resources among different network operating entities can be centrally controlled by a single entity, autonomously determined through a predefined arbitration scheme, or dynamically determined based on the interaction between wireless nodes of the network operator.

[0061] In some scenarios, UE 115 and base station 105 may operate in a shared radio spectrum band, which may include licensed or unlicensed (e.g., contention-based) spectrum. In the unlicensed frequency portion of the shared radio spectrum band, UE 115 or base station 105 may conventionally perform media sensing procedures to contend for access to the spectrum. For example, UE 115 or base station 105 may perform Listen-Before-Speak or Listen-Before-Transmit (LBT) procedures (such as Open Channel Assessment (CCA)) before communication to determine if a shared channel is available. In some implementations, CCA may include energy detection procedures to determine the presence of any other active transmissions. For example, the device may infer that a change in the Received Signal Strength Indicator (RSSI) of the power meter indicates that the channel is occupied. Specifically, signal power concentrated in a specific bandwidth and exceeding a predetermined noise floor may indicate another wireless transmitter. CCA may also include the detection of a specific sequence indicating channel usage. For example, another device may transmit a specific preamble before transmitting a data sequence. In some cases, LBT procedures may include radio nodes acting as collision-proxies adjusting their own backoff windows based on the amount of energy detected on the channel and / or ACK / NACK feedback on their own transmitted packets.

[0062] Various technologies for carrying user traffic between network nodes have been used to facilitate communication in wireless networks. For example, integrated access and backhaul (IAB) or consumer equipment (CPE) communication configurations have been implemented in some scenarios.

[0063] Figure 3An example of an IAB communication configuration is shown, in which an intermediate node (e.g., base station 105f providing small cells, operating as a relay) transmits user data between a network node (e.g., base station 105d) and another device (e.g., UE 115g). As illustrated in the example, the IAB communication configuration provides a Layer 2 (i.e., data link layer) communication solution, where both the backhaul between the intermediate node and the network node (e.g., provided by link 301) and the access between the intermediate node and the other device (e.g., provided by link 302) are controlled by the network (e.g., base station 105d).

[0064] Figure 4 An example of a CPE communication configuration is illustrated, in which an intermediate node (e.g., a CPE including UE 115i) communicates user data (e.g., received from and / or originated by a network node such as base station 105e) to another device (e.g., UE 115j). As illustrated in the example, the CPE communication configuration provides a Layer 3 (i.e., network layer) communication solution, where the backhaul between the intermediate node and the network node (e.g., provided by link 401) is controlled by the network (e.g., base station 105e), while the access between the intermediate node and the other device (e.g., provided by link 402) is controlled by the intermediate node (e.g., UE 115i). The CPE providing the intermediate node for the CPE communication configuration may include various forms of equipment, such as various UE devices (e.g., smartphones, set-top boxes, wireless routers, or other access points, etc.). Although the intermediate node of the CPE communication configuration is referred to herein as a UE, it should be understood that the intermediate node of the CPE communication configuration is not limited to any particular UE configuration or even devices generally considered to be UEs.

[0065] As by Figure 4 As explained in the CPE communication configuration, in addition to communicating with the network (e.g., base station 105e), the UE (e.g., UE 115i) can also establish side links (i.e., direct communication links between UEs) relative to one or more other UEs (e.g., UE 115j). UE 115i can communicate directly with base station 105e using a UE-to-UMTS (Uu) interface. Side links can be implemented, for example, using a UE-to-UE interface (such as the PC5 interface in a vehicle-to-everything (V2X) mesh network).

[0066] Existing V2X interface protocols provide dynamic and configured granting for sidelinks using the PC5 interface (e.g., Physical Sidelink Control Channel (PSCCH) and / or Physical Sidelink Shared Channel). Dynamic granting (DG) can provide one-time granting of sidelink resources in response to an instantaneous demand / need for sidelink communication. Configured granting (CG) provides granting of sidelink resources for enabling continuous / periodic / repetitive sidelink communication. A first type of sidelink resource granting (Type 1) in V2X interface protocols uses Radio Resource Control (RRC) to configure the UE with resources having a CG. A second type of sidelink resource granting (Type 2) in V2X interface protocols uses Downlink Control Information (DCI) on the PDCCH to configure the UE with resources having either a DG or a CG. For example, the DCI can be a DG, providing the allocation of resources to be used for sidelink communication. Alternatively, the DCI can be a CG, activating / deactivating the CG for sidelink communication.

[0067] The base station (e.g., base station 105e) schedules sidelink resources for use by a UE (e.g., UE 115i) in V2X transmission mode 1 (mode 1) via PC5 to connect to another UE (e.g., UE 115j) for sidelink transmission, such as... Figure 5A As explained in the text. Mode 1 supports Type 1 DG and CG, as well as Type 2 CG. Type 1 CG can be activated, for example, via RRC signaling from the base station. Type 2 DG and CG can be communicated using DCI format 3_0 messages on the PDCCH. For example, the DCI may include DG and provide allocation of resources to be used on the sidelink. As another example, the DCI can activate or deactivate Type 2 CG for the sidelink. The UE (e.g., UE 115i) can use Media Access Control-Control Element (MAC-CE) signaling to report activation / deactivation of the sidelink.

[0068] Figure 5B This describes the physical layer procedure flow (procedure flow 500) for Mode 1, which uses sidelink resource granting according to the V2X interface DG / CG Type 2 protocol mentioned above. It is described with reference to the V2X mesh network between UEs 115i and 115j communicating with macro base station 105e. Figure 5B The procedure flow 500, such as Figure 1 The wireless network 100 is shown. However, it should be understood that this procedure flow can be implemented with respect to various UEs and UE configurations.

[0069] exist Figure 5BIn procedure flow 500, at procedure 501, base station 105e uses the DCI provided according to DCI format 3_0 and configured to correspond to UE 115i (e.g., sidelink transmitter (TX) UE) to transmit DG / CG type 2 to UE 115i. DCI format 3_0 provides fields for time slots, Hybrid Automatic Repeat Request (HARQ) procedure identifier (ID), new data indicator, minimum index of subchannel allocation for initial transmission, Phase 1 Sidelink Control Information (SCI) format 0-1 fields (including frequency resource allocation and time resource allocation), Physical Sidelink Feedback Channel (PSFCH) to HARQ feedback timing indicator, and PUCCH resource indicator, as well as configuration index in the CG case. In the case of DG, base station 105e prepares DCI using the sidelink-radio network temporary identifier (SL-RNTI) of UE 115i, or in the case of CG, it prepares DCI using the sidelink-configured scheduled-radio network temporary identifier (SL-CS-RNTI) of UE 115i, to configure DCI to correspond to UE 115i. Specifically, the cyclic redundancy check (CRC) of DCI is scrambled by the SL-RNTI or SL-CS-RNTI of UE 115i to transmit DG / CG type 2 to the UE (e.g., sidelink TX UE).

[0070] In the case of CG, UE 115i (e.g., a sidelink TX UE) reports the activation (or deactivation) of the sidelink (not shown in procedure flow 500). Specifically, the activation / deactivation of the CG sidelink is reported via MAC-CE. The MAC-CE report is also used by UE 115i to provide a sidelink buffer status report (BSR) to base station 105e. For example, UE 115i may have provided a BSR indicating that data for sidelink communication is included in the UE buffer, thereby causing base station 115e to initiate sidelink resource granting in procedure 501.

[0071] At procedure 502 of procedure flow 500, UE 115i (e.g., a sidelink TX UE) schedules the PSSCH using SCIs provided according to SCI format 0-1 (e.g., for scheduling the Physical Sidelink Shared Channel (PSSCH) and the second-stage SCI on the PSSCH) and SCI format 0-2 (e.g., for decoding the PSSCH), and transmits data to UE 115j (e.g., a sidelink receiver (RX) UE) via the PSSCH according to DG / CG type 2 (sidelink resource granting in procedure 501). SCI format 0-1 provides fields for priority, frequency resource allocation, time resource allocation, resource reservation period, demodulation reference signal (DMRS) mode, second-stage SCI format (broadcast, unicast, multicast), Beta_offset indicator, number of DMRS ports, modulation and coding scheme (MCS), and reserved fields. SCI format 0-2 provides fields for HARQ procedure ID, new data indicator, redundancy version, source ID, destination ID, and channel state information (CSI) requests, and if the second-stage SCI format field in the corresponding SCI provided in SCI format 0-1 indicates type 1, then multicast zone ID and communication range requirement fields are present. Within the constraints set by the base station (e.g., base station 105e), MCS selection depends on the sidelink TX UE (e.g., UE115i in procedure flow 500).

[0072] As can be seen from the foregoing, the base station schedules node resources for the sidelink TX UE (Procedure 501), and the sidelink TX UE uses some or all of the scheduled resources to establish one or more sidelinks with the sidelink RX UE (Procedure 502). However, the base station does not control how the sidelink TX UE (e.g., UE 115i) uses these resources or which UEs are selected by the sidelink TX UE as the sidelink RX UE.

[0073] continue Figure 5B In procedure flow 500, at procedure 503, UE 115j (e.g., a sidelink RX UE) provides sidelink feedback to UE 115i (e.g., a sidelink TX UE). As mentioned above, three transmission types are specified in SCI 0-1: unicast, broadcast, and multicast. For unicast or multicast, each RX UE sends an ACK / NACK on the PSFCH upon receiving each transmission, where there are two feedback options for multicast: (i) NACK only; and (ii) ACK and NACK.

[0074] At procedure 504 of procedure flow 500, UE 115i (e.g., a sidelink TX UE) forwards the sidelink feedback provided by UE 115j (e.g., a sidelink RX UE) to base station 105e. Specifically, UE 115i forwards the ACK / NACK received from UE 115j to base station 105e on the PUCCH. The feedback can be used, for example, to request resources for data retransmission to one or more sidelink RX UEs.

[0075] The UE (e.g., UE 115i) determines sidelink resources for its use in V2X transport mode 2 (mode 2) to connect via PC5 to another UE (e.g., UE 115j) for sidelink transmission, such as... Figure 6A As explained in the document, the sidelink resources used for sidelink transmission can be selected by the sidelink TX UE (e.g., UE115i) from the sidelink resources configured by the network (e.g., base station 105e via type 1DG or CG or type 2CG). Alternatively or additionally, the sidelink resources used for sidelink transmission can be selected by the sidelink TX UE (e.g., UE 115i) from pre-configured sidelink resources.

[0076] Figure 6B This section explains the physical layer procedure flow (procedure flow 600) for Mode 2 using sidelink resources configured by the network or sidelink resources from pre-configured sidelink resources. It is described with reference to the V2X mesh network between UEs 115i and 115j communicating with macro base station 105e. Figure 6B The procedure flow 600, such as Figure 1 The wireless network 100 is shown. However, it should be understood that this procedure flow can be implemented with respect to various UEs and UE configurations.

[0077] According to Figure 6B In the operation of procedure flow 600, UE 115i (e.g., a sidelink TX UE) senses and selects resources for use when providing sidelinks with one or more sidelink RX UEs (e.g., UE 115j). For example, UE 115i may sense and select resources based on all SCI 0-1 messages and the reference signal received power (RSRP) measurement of the DMRS within the PSSCH or PSCCH.

[0078] At procedure 601 of procedure flow 600, UE 115i (e.g., a sidelink TX UE) schedules the PSSCH using SCI according to SCI format 0-1 (e.g., for scheduling the Physical Sidelink Shared Channel (PSSCH) and the second-stage SCI on the PSSCH) and SCI format 0-2 (e.g., for decoding the PSSCH) and transmits data (e.g., one or more transport blocks (TBs) including user data and / or other data) to UE 115j (e.g., a sidelink RX UE) via the PSSCH using sidelink resources selected for sidelink communication. As described above, SCI format 0-1 provides fields for priority, frequency resource allocation, time resource allocation, resource reservation period, DMRS mode, second-stage SCI format (broadcast, unicast, multicast), β_offset indicator, number of DMRS ports, MCS, and reservation fields. SCI format 0-2 provides fields for HARQ process ID, new data indicator, redundant version, source ID, destination ID, and CSI request, and if the second-stage SCI format field in the corresponding SCI provided in SCI format 0-1 indicates type 1, then there are multicast zone ID and communication range requirement fields.

[0079] exist Figure 6B At procedure 602 of procedure flow 600, UE 115j (e.g., a sidelink RX UE) provides sidelink feedback to UE 115i (e.g., a sidelink TX UE). As mentioned above, three transmission types are specified in SCI 0-1: unicast, broadcast, and multicast. For unicast or multicast, each RX UE sends an ACK / NACK on the PSFCH upon receiving each transmission, where there are two feedback options for multicast: (i) NACK only; and (ii) ACK and NACK.

[0080] Figure 7 CPE communication configuration 700 is described, in which an intermediate node (e.g., UE 115r) is operable to periodically transmit multicast messages to one or more UE groups (e.g., UEs 115s, 115t, 115u, and 115v comprising groups 701, 702, and 703). It should be understood that the specific grouping of UEs and the UEs included in each group are illustrative and may not precisely correspond to the configuration of any particular implementation. For example, according to some aspects of this disclosure, the number of UEs in a group, the number of groups, the inclusion of UEs in more than one group, etc., may differ from those shown in the example of CPE communication configuration 700.

[0081] exist Figure 7 In the example CPE communication configuration 700, base station 105 and UE 115r-115v can include various configurations, such as those referenced above. Figure 1Any configuration discussed. UE 115r, acting as an intermediate UE providing a side link relative to UE 115s-115v, may include, for example, a smartphone, set-top box, wireless router, or other access point, providing periodic multicast message transmissions to some or all of the UEs in UE 115s-115v. These periodic multicast messages, as an example, may originate from a video / voice streaming application. Multiple multicasts may coexist, such as to enable multicasting of different video / voice streams to UEs in each of groups 701, 702, and 703.

[0082] Semi-persistent scheduling (SPS) is implemented according to various aspects of this disclosure to facilitate the transmission of periodic messages via one or more sidelinks (e.g., sidelinks of CPE communication configuration 700). However, existing V2X protocols do not support SPS for sidelink multicast. Instead, current PC5 interface protocols require sidelink TX UEs in a group of sidelinks to use periodic PSSCH data to multicast SCI format 0-1 and SCI format 0-2 messages, even if the SCI format 0-1 and SCI format 0-2 messages remain unchanged.

[0083] In a sidelink multicast SPS implementation according to some aspects of this disclosure, a sidelink TX UE (e.g., UE 115r of CPE communication configuration 700) may transmit group SPS activation / deactivation to a group of sidelink RX UEs (e.g., UEs 115s and 115t of group 701, UEs 115t and 115u of group 702, or UEs 115u and 115v of group 703) via SCI format 0-1 and SCI format 0-2 messages transmitted along with the first PSSCH data of the sidelink multicast. After activation, the transmission of both SCI format 0-1 and SCI format 0-2 messages may be omitted relative to subsequent PSSCH data transmissions of the sidelink multicast. As another example, after activation, a sidelink TX UE (e.g., UE 115r operating in V2X mode 2) can transmit SCI format 0-1 messages and omit the transmission of SCI format 0-2 messages relative to subsequent PSSCH data transmissions of the sidelink multicast (e.g., continued transmission of SCI format 0-1 messages can be used by the sidelink TX UE to maintain existing resource-sensing procedures for mode 2 operation). In both examples above, control overhead is reduced relative to sidelink multicast. This reduced control overhead can provide improved reliability relative to periodic sidelink multicast data, such as by freeing up bandwidth of sidelink resources for more robust PSSCH data transmission.

[0084] Figure 8 and 9An example flowchart of SPS operation for sidelink multicast according to some aspects of this disclosure is shown. Specifically, Figure 8 A flow 800 is shown that provides an operation for facilitating SPS to sidelink multicast, which can be implemented by a sidelink TX UE (e.g., UE 115r of CPE communication configuration 700). Accordingly, Figure 9 A process 900 is shown that provides an operation for facilitating SPS to sidelink multicast, which can be implemented by a sidelink RX UE (e.g., any or all UEs of UE 115s-115v in CPE communication configuration 700).

[0085] First refer to Figure 8 In facilitating SPS sidelink multicast, a sidelink TX UE can transmit group SPS activation / deactivation to a group of sidelink RX UEs. According to some aspects of this disclosure, group SPS activation / deactivation for sidelink multicast can be transmitted to a group of sidelink RX UEs via SCI format 0-1 and SCI format 0-2 messages (e.g., SCI format 0-1 and SCI format 0-2 messages transmitted along with the first PSSCH data of the sidelink multicast).

[0086] according to Figure 8 In an example of the flow 800 shown, a first UE (e.g., UE 115r of CPE communication configuration 700) may transmit a multicast indicator in block 801, which indicates that a corresponding sidelink transmission is multicast to multiple UEs (e.g., UEs 115s and 115t of group 701, UEs 115t and 115u of group 702, or UEs 115u and 115v of group 703). For example, according to aspects of this disclosure, wireless communication resources of a sidelink TX UE (e.g., UE 115r) (e.g., one or more wireless radios, such as a transmit processor 264, a TX MIMO processor 266, and / or MOD / DEMOD 254a to 254r, which may operate under the control of one or more controllers / processors (e.g., controller / processor 280 that performs SPS sidelink multicast logic) may be used to transmit a multicast indicator for sidelink multicast. The multicast indicator disclosed herein may be transmitted at least in part via a field of an SCI Format 0-1 message or a field of an SCI Format 0-2 message. The multicast indicator may be transmitted, for example, at least in part via an SCI Format 0-1 message (e.g., using the “SCI 0-2 Format” field of an SCI Format 0-1 message to indicate that the sidelink transmission is “multicast”) to a group of sidelink RX UEs.

[0087] For any given combination of SCI 0-1 and SCI 0-2 that can be used for sidelink multicast, a TX UE that has been granted resources by the corresponding base station or otherwise has pre-configured sidelink resources can use SPS control signaling for sidelink multicast to activate and / or deactivate the SPS for sidelink multicast. According to some aspects of this disclosure, the SPS control signaling used to activate / deactivate the SPS for sidelink multicast may include an SPS indicator (e.g., communicated at least in part via an SCI format 0-1 message), an activation / deactivation indicator (e.g., communicated at least in part via an SCI format 0-1 message and / or an SCI format 0-2 message), and a configuration index (e.g., communicated at least in part via one or more fields of an SCI format 0-1 message and / or an SCI format 0-2 message). In the example of process 800, a first UE (e.g., UE 115r of CPE communication configuration 700) may transmit SPS control signaling for sidelink multicast in block 802, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index. For example, according to aspects of this disclosure, the wireless communication resources of a sidelink TX UE (e.g., UE 115r) (e.g., one or more wireless radios, such as a transmit processor 264, a TX MIMO processor 266, and / or MOD / DEMOD 254a to 254r that may operate under the control of one or more controllers / processors (e.g., controller / processor 280 that performs SPS sidelink multicast logic) may be used to transmit SPS control signaling for sidelink multicast.

[0088] According to various aspects of this disclosure, the SPS indicator for SPS control signaling used to activate / deactivate SPS for crosslink multicast can be conveyed using an SCI-formatted 0-1 message (e.g., transmitted at least partially via one or more fields of the SCI-formatted 0-1 message). In some examples, the CRC included in the fields of the SCI-formatted 0-1 message can be scrambled using an SPS RNTI used to provide the SPS indicator. Additionally or alternatively, the fields of the SCI message can be defined to provide the SPS indicator.

[0089] According to some aspects of this disclosure, the SPS RNTI used to provide the SPS indicator may include a shared sidelink SPS RNTI (SL-SPS-RNTI) shared by all UEs (e.g., all UEs from UE 115s to 115r, regardless of the UE group used for sidelink multicast) that are in sidelink communication with the first UE (e.g., UE 115r). For example, the SPS indicator may be transmitted at least in part by scrambling the CRC of an SCI format 0-1 message using the shared SL-SPS-RNTI shared by all UEs in sidelink communication with the first UE. In an implementation where the CRC is scrambled using the shared SL-SPS-RNTI, any decoding UE can understand that the SCI format 0-1 message and the subsequent SCI format 0-2 message contain group SPS information. Accordingly, the shared SL-SPS-RNTI may indicate that the SCI format 0-1 message and the corresponding SCI format 0-2 message contain SPS information for sidelink multicast.

[0090] According to some aspects of this disclosure, the SPS RNTI used to provide the SPS indicator may include a group-specific RNTI (SL-SPS-group-RNTI) for a group of multicast RX UEs (e.g., UEs 115s and 115t, UEs 115t and 115u, or UEs 115u and 115v in a specific group of groups 701, 702, or 703 for sidelink multicast). The SL-SPS-group-RNTI used for CRC scrambling of SCI format 0-1 messages can thus indicate the SPS for a specific group of RX UEs. According to some examples, the multicast indicator and the SPS indicator may be jointly transmitted, at least in part, by using the SL-SPS-group-RNTI for CRC scrambling of SCI format 0-1 messages that includes a group of multicast receiving UEs comprising multiple UEs. According to some aspects of this disclosure, if the indicated group matches the group indicated in the SCI format 0-2 message, the 12-bit destination group ID and 4-bit zone ID in the corresponding SCI format 0-2 message can be used for other purposes (e.g., carrying other information). Accordingly, according to some aspects of this disclosure, when the group indicated by SL-SPS-group-RNTI matches the group indicated in the SCI format 0-2 message corresponding to the SCI format 0-1 message, the message destination group ID and / or zone ID in the corresponding SCI format 0-2 message can be used for purposes other than the destination group ID and zone ID. When the number of groups is small (e.g., less than 10 groups), this operation can save significant resources compared to using a shared SL-SPS-RNTI.

[0091] According to some aspects of this disclosure, additional fields (e.g., a 1-bit SPS indicator field) can be added within SCI format 0-1 to indicate the presence of group SPS information in SCI format 0-1 messages and / or corresponding SCI format 0-2 messages. Accordingly, the fields defined in the SCI format 0-1 message to indicate the presence of SPS information in SCI format 0-1 messages and corresponding SCI format 0-2 messages can provide SPS indicators for SPS control signaling.

[0092] According to various aspects of this disclosure, the activation status indicator for SPS control signaling used to activate / deactivate the SPS of a peer-to-peer multicast link (PML) can be conveyed using SCI format 0-1 messages and / or SCI format 0-2 messages. The activation status indicator can, for example, indicate the activation or deactivation of the PML for the peer-to-peer multicast link (PML). In some examples, a combination of fields from SCI format 0-1 messages and / or SCI format 0-2 messages can be used to provide the activation status indicator. Additionally or alternatively, fields of the SCI message can be defined to provide the activation status indicator.

[0093] According to some aspects of this disclosure, the activation status indicator is transmitted at least in part via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof. For example, a combination of the contents of at least one field of an SCI format 0-1 message and at least one field of an SCI format 0-2 message can provide an activation status indicator for SPS control signaling. The field contents of the SCI format 0-1 message (e.g., specifying one or more bits of the group SPS) can indicate the group SPS, while the field contents of the SCI format 0-2 message can indicate new data, wherein the combination of these indicators provides the activation status indicator. As an example, when the field contents of the SCI format 0-1 message indicate the group SPS, the field contents of the SCI format 0-2 message indicate a predetermined new data field value (e.g., new data field value 0), and frequency and time resources for sidelink multicast are assigned practicable (e.g., valid values, available for UE implementation, etc.), the activation status indicator can indicate activation of the SPS for sidelink multicast. Similarly, when the field content of an SCI format 0-1 message indicates group SPS, the field content of an SCI format 0-2 message includes a predetermined new data field value (e.g., new data field value 0), and the allocation of frequency and time resources for sidelink multicast is not feasible (e.g., invalid values ​​(such as all set to all 0), not available to the UE, etc.), the activation status indicator can indicate the deactivation of SPS for sidelink multicast.

[0094] According to some aspects of this disclosure, additional fields (e.g., a 1-bit activation status indicator field) may be added within SCI format 0-1 and / or SCI format 0-2 to indicate the activation / deactivation of the SPS for crosslink multicast. Accordingly, the fields defined in the SCI format 0-1 message to indicate the activation status of the SPS for crosslink multicast and / or the fields defined in the SCI format 0-2 message to indicate that activation status can provide activation status indicators for SPS control signaling.

[0095] The configuration index for SPS control signaling used to activate / deactivate SPS for crosslink multicast according to various aspects of this disclosure may be conveyed using SCI format 0-1 messages and / or SCI format 0-2 messages. In some examples, one or a combination of fields from SCI format 0-1 messages and / or SCI format 0-2 messages may be used to provide the configuration index. The configuration index may be transmitted, for example, at least in part, via fields indicating the group SPS in SCI format 0-1 messages or SCI format 0-2 messages. Additionally or alternatively, fields of the SCI messages may be defined to provide the configuration index.

[0096] According to some aspects of this disclosure, a combination of content provides a configuration index for the SPS of the sidelink multicast. For example, according to aspects of this disclosure, a combination of some bits of the content of the field content of the SCI format 0-1 message (e.g., content indicating the group SPS) and the HARQ procedure ID field (e.g., the SCI format 0-2 HARQ procedure ID field) can provide a configuration index. Accordingly, in the case where the SCI format 0-1 message indicates the group SPS, one or more bits of the HARQ procedure ID in the HARQ procedure ID field of the corresponding SCI format 0-2 message can specify the index value of the configuration index.

[0097] According to some aspects of this disclosure, additional fields (e.g., configuration index fields, which may include 1, 2, 3 bits, etc., depending on the number of configurations being indexed) may be added within SCI format 0-1 and / or SCI format 0-2 to indicate the configuration index of the SPS for the crosslink multicast. Accordingly, the fields in the SCI format 0-1 message defined to indicate the configuration index of the SPS for the crosslink multicast and / or the fields in the SCI format 0-2 message defined to indicate that the configuration index can provide the configuration index for the SPS control signaling.

[0098] According to some aspects of this disclosure, the configuration index can provide an index for one or more parameters in a parameter set used for SPS sidelink multicast. For example, the configuration index may correspond to a database of various SPS sidelink multicast configuration parameters (e.g., stored by some or all of the UEs in UE 115r-115v), where each configuration may include parameters such as one or more of the following: SPS RNTI, periodicity of sidelink multicast, and / or the maximum number of times a TB can be transmitted for sidelink multicast. According to some aspects, the SPS sidelink multicast configuration may be pre-configured (e.g., pre-configured by TX UEs, base stations, etc.), whereby the configuration index can be used to select and / or agree on the SPS sidelink multicast configuration for a particular multicast group between TX UEs and RX UE groups. Accordingly, the configuration index, based on various aspects of this disclosure, can identify the group SPS configuration for SPS sidelink multicast, such as parameters that can be provided, such as SL-SPS-RNTI or SL-SPS-group-RNTI (e.g., for activation, deactivation, and retransmission), the periodicity of the group SPS, and the maximum number of times a TB can be transmitted using the configured parameters. According to some examples, the multicast indicator, SPS indicator, and configuration index together indicate the set of parameters associated with the SPS for sidelink multicast (e.g., one or more parameters, such as the periodicity of the sidelink multicast, or the maximum number of times a TB can be transmitted for sidelink multicast, etc.).

[0099] Apart from Figure 8 In addition to the functions explicitly shown in the boxes of the example flow 800 illustrated, operations for SPS sidelink multicast according to some aspects of this disclosure may include further TX UE actions relative to SPS sidelink multicast activation and / or deactivation. For example, activation of SPS sidelink multicast (e.g., resources may be provided for it by a received CG) may be performed by transmitting an SPS sidelink multicast activation indication and then determining whether the activation is considered complete or incomplete.

[0100] As described above, the TX UE can transmit multicast indicators and SPS control signaling, such as by transmitting an SCI format 0-1 message and a corresponding SCI format 0-2 message, followed by PSSCH multicast data, wherein these two SCIs are configured to indicate group SPS activation and SPS configuration. Accordingly, the first UE (e.g., UE 115r of CPE communication configuration 700) can transmit a first SCI format 0-1 message for sidelink multicast, transmit a first SCI format 0-2 message for sidelink multicast (e.g., SPS control signaling for sidelink multicast can be included in the SCI format 0-1 message, the SCI format 0-2 message, or a combination thereof), and transmit PSSCH multicast data for sidelink multicast.

[0101] According to various aspects of this disclosure, SPS configuration activation can be considered complete if the TX UE has received at least one feedback message (e.g., feedback on the PSFCH) from each RX UE in the target group. Accordingly, the first UE (e.g., UE115r) can monitor feedback messages from each of the plurality of UEs in the SPS sidelink multicast group, and if feedback messages have been received from each of the plurality of UEs, then (e.g., using the controller / processor 280 that performs the SPS sidelink multicast logic) it is determined that SPS activation for the sidelink multicast is complete.

[0102] According to some aspects of this disclosure, after SPS configuration activation is completed, subsequent PSSCH data transmission may not be accompanied by repeated SCI format 0-1 and SCI format 0-2 messages. For example, when it is determined that the activation of SPS for sidelink multicast is complete, subsequent PSSCH multicast data transmission for sidelink multicast may not be accompanied by SCI format 0-1 messages, SCI format 0-2 messages, or both. For example, when the activation status indicator indicates the activation of SPS for sidelink multicast, after a feedback message has been received from each of the plurality of UEs and the activation of SPS for sidelink multicast is complete, subsequent PSSCH multicast data transmission for sidelink multicast may not be accompanied by SCI or may only be accompanied by SCI format 0-1 messages. In an example where the TX UE operates in V2X mode 1 (e.g., sidelink resources for sidelink multicast are scheduled by a base station communicating with the TX UE), the TX UE may (e.g., using a controller / processor 280 that performs SPS sidelink multicast logic) determine that the content of the SCI format 0-1 message and the content of the SCI format 0-2 message associated with an instance of subsequent PSSCH multicast data transmission are equivalent to the content of the corresponding one of the first SCI format 0-1 message and the first SCI format 0-2 message, and transmit subsequent PSSCH multicast data transmission for sidelink multicast without the accompanying SCI format 0-1 message and SCI format 0-2 message. In an example where the TXUE operates in V2X mode 2 (e.g., sidelink resources for sidelink multicast are scheduled by the TXUE), the TXUE may (e.g., using a controller / processor 280 that performs SPS sidelink multicast logic) determine that the content of the SCI format 0-1 message and the content of the SCI format 0-2 message associated with an instance of subsequent PSSCH multicast data transmission are equivalent to the content of one of the corresponding first SCI format 0-1 message and the first SCI format 0-2 message, and transmit instances of subsequent PSSCH multicast data transmission for sidelink multicast accompanied by an SCI format 0-1 message but not accompanied by an SCI format 0-2 message.

[0103] If the TX UE has not yet received a feedback message (e.g., feedback on the PSFCH) from each RX UE in the target group, the SPS configuration activation may be considered incomplete. Accordingly, the first UE (e.g., UE 115r) may monitor feedback messages from each of the multiple UEs in the SPS sidelink multicast group, and if no feedback message has been received from any of those multiple UEs, then (e.g., using the controller / processor 280 executing the SPS sidelink multicast logic) it is determined that the SPS activation for the sidelink multicast is incomplete. When activation is considered incomplete, subsequent PSSCH multicast data transmission for the sidelink multicast may be accompanied by a first SCI format 0-1 message and a second SCI format 0-2 message. For example, subsequent PSSCH data transmitted according to the SPS sidelink multicast may previously contain the same SCI format 0-1 and SCI format 0-2 messages to indicate the same SPS activation (e.g., until activation of the SPS configuration is considered complete, such as due to receiving appropriate feedback messages from all UEs in the target group).

[0104] The deactivation of SPS sidelink multicast can be performed using functionality similar to that described above for SPS sidelink multicast activation. For example, SPS control signaling similar to SPS control signaling for SPS sidelink multicast activation, except for having different content for the activation status indicator, can be used to deactivate SPS sidelink multicast. According to some aspects of the invention, a first UE (e.g., UE 115r) can transmit a second SCI format 0-1 message and a second SCI format 0-2 message for sidelink multicast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or a combination thereof provides an activation status indicator indicating the deactivation of SPS for sidelink multicast.

[0105] Additionally or alternatively, the reactivation of disabled SPS sidelink multicast and / or the update of the SPS configuration for SPS sidelink multicast can be performed using functionality similar to that described above for SPS sidelink multicast activation. For example, SPS control signaling similar to that used for SPS sidelink multicast activation, except for messages with updated SCI format 0-1 and / or updated SCI format 0-2, can be used for the reactivation and / or update of SPS sidelink multicast. For example, a TX UE that changes the MCS for sidelink multicast can transmit an SCI format 0-1 message with updated MCS fields (e.g., as if activating the same SPS configuration) and a corresponding SCI format 0-2 message (e.g., configured to indicate group SPS activation and SPS configuration). According to some aspects of this disclosure, a first UE (e.g., UE115r) may transmit a second SCI format 0-1 message for sidelink multicast, and a second SCI format 0-2 message for sidelink multicast (e.g., the second SCI format 0-1 message, the second SCI format 0-2 message, or both may include content updated relative to the first SCI format 0-1 message, the first SPS format 0-2 message, or both, and an activation status indicator may indicate activation of SPS for sidelink multicast) for reactivating or updating SPS sidelink multicast using a different SPS configuration.

[0106] After describing an example operation of the sidelink TX UE, now refer to Figure 9 To obtain the operation of the sidelink RX UE in facilitating SPS sidelink multicast. In facilitating SPS sidelink multicast, the sidelink RX UE may receive group SPS activation / deactivation for the target group of the sidelink RX UE transmitted by the sidelink TX UE. According to some aspects of this disclosure, group SPS activation / deactivation for sidelink multicast may be received at least in part via SCI format 0-1 and SCI format 0-2 messages (e.g., SCI format 0-1 and SCI format 0-2 messages received together with the first PSSCH data of the sidelink multicast).

[0107] according to Figure 9In the example of process 900 shown, UEs in a group of UEs communicating with the first UE (e.g., UE 115r) (e.g., UEs 115s-115v in the target group of CPE communication configuration 700 in groups 701-703) can receive a multicast indicator in block 901, which indicates that the corresponding sidelink transmission is multicast to multiple UEs (e.g., UEs 115s and 115t in group 701, UEs 115t and 115u in group 702, or UEs 115u and 115v in group 703). For example, according to various aspects of this disclosure, the wireless communication resources of a sidelink RX UE (e.g., UEs in UEs 115s-115v) (e.g., one or more wireless radios, such as MOD / DEMOD 254a to 254r, MIMO detector 256, and receive processor 258, which may operate under the control of one or more controllers / processors (e.g., controller / processor 280 performing SPS sidelink multicast logic) can be used to receive multicast indicators for sidelink multicast. The multicast indicators of this disclosure can be received at least partially via a field of an SCI format 0-1 message or a field of an SCI format 0-2 message. The multicast indicator can be received, for example, at least partially by a group of UEs in a group of sidelink RX UEs via an SCI format 0-1 message (e.g., the “SCI 0-2 format” field of an SCI format 0-1 message indicates that the sidelink transmission is “multicast”).

[0108] For any given combination of SCI 0-1 and SCI 0-2 that can be used for sidelink multicast, the SPS for sidelink multicast can be activated / deactivated using SPS control signaling for sidelink multicast. According to some aspects of this disclosure, the SPS control signaling used to activate / deactivate the SPS for sidelink multicast may include an SPS indicator (e.g., communicated at least partially via an SCI format 0-1 message), an activation / deactivation indicator (e.g., communicated at least partially via an SCI format 0-1 message and / or an SCI format 0-2 message), and a configuration index (e.g., communicated at least partially via an SCI format 0-1 message and / or an SCI format 0-2 message). In the example of process 900, UEs among a plurality of UEs communicating with the first UE (e.g., UE 115r) (e.g., UEs in the target group of groups 701-703 of CPE communication configuration 700, UEs 115s-115r) may receive SPS control signaling for sidelink multicast in block 902, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index. For example, according to aspects of this disclosure, the wireless communication resources of a sidelink RX UE (e.g., UEs in UEs 115s-115v) (e.g., one or more radios, such as MOD / DEMOD 254a to 254r, MIMO detector 256, and receive processor 258, which may operate under the control of one or more controllers / processors (e.g., controller / processor 280 that performs SPS sidelink multicast logic) may be used to receive SPS control signaling for sidelink multicast.

[0109] According to some aspects of this disclosure, the SPS indicator may be received at least partially via one or more fields of an SCI format 0-1 message. For example, the CRC included in a field of the SCI format 0-1 message may be scrambled using an SPS RNTI (e.g., an SPS RNTI of the SPS configuration indicated by a configuration index for SPS sidelink multicast) to provide the SPS indicator. In one example, the SPS RNTI may be a shared SL-SPS-RNTI shared by all UEs (e.g., all UEs in UE115s-115v, regardless of the UE group for sidelink multicast) that are in sidelink communication with the first UE (e.g., UE 115r). For example, the SPS indicator may be received at least partially via a CRC of an SCI format 0-1 message that is scrambled using a shared SL-SPS-RNTI shared by all UEs in sidelink communication with the first UE. The shared SL-SPS-RNTI may indicate that the SCI format 0-1 message and the corresponding SCI format 0-2 message contain SPS information for sidelink multicast. In another example, the SPS RNTI could be an SL-SPS-group-RNTI for a group of multicast RX UEs (e.g., UEs 115s and 115t, UEs 115t and 115u, or UEs 115u and 115v in a specific group of groups 701, 702, or 703 for sidelink multicast). According to some examples, the multicast indicator and the SPS indicator can be received jointly, at least in part, by the CRC of an SCI format 0-1 message, which is scrambled using the SL-SPS-group-RNTI for a group of multicast receiving UEs comprising multiple UEs. Additionally or alternatively, an extra field (e.g., a 1-bit SPS indicator field) can be added within the SCI format 0-1 to indicate the presence of group SPS information in the SCI format 0-1 message and / or the corresponding SCI format 0-2 message. Accordingly, the SCI format 0-1 message is defined as a field used to indicate the existence of SPS information in the SCI format 0-1 message and the corresponding SCI format 0-2 message, which can provide an SPS indicator for SPS control signaling.

[0110] According to some aspects of this disclosure, an activation status indicator indicates the activation or deactivation of a peer-link multicast SPS. The activation status indicator may be received, for example, at least partially, via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof. In one example, an activation status indicator is provided by a combination of field content from an SCI format 0-1 message (e.g., SCI format 0-1 message content indicating a multicast SPS) and field content from an SCI format 0-2 message (e.g., SCI format 0-2 message content including a new data indicator). Additionally or alternatively, fields from an SCI format 0-1 message or a SCI format 0-2 message may be defined to indicate the activation status of a peer-link multicast SPS, and thereby used to provide the activation status indicator.

[0111] According to some aspects of this disclosure, the configuration index can be received at least partially via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof. The configuration index can be received, for example, at least partially via a field of the indicator group SPS of an SCI format 0-1 message or an SCI format 0-2 message. The configuration index can be received, for example, at least partially via a combination of the content of the SCI format 0-1 message (e.g., the SCI format 0-1 message content of the indicator group SPS) and some bits of the HARQ procedure ID field (e.g., the SCI format 0-2 HARQ procedure ID field). Accordingly, in the case of an SCI format 0-1 message indicating an SPS, one or more bits of the HARQ procedure ID in the corresponding HARQ procedure ID field of the SCI format 0-2 message can specify the index value of the configuration index. Additionally or alternatively, fields of the SCI format 0-1 message or SCI format 0-2 message can be defined as index values ​​for indicating the configuration index, and thus can be used to provide the configuration index.

[0112] A configuration index provides an index for one or more parameters in a parameter set, which includes one or more of the following: SPS RNTI, periodicity of sidelink multicast, and / or the maximum number of times a TB can be transmitted for sidelink multicast. For example, the configuration index may correspond to a database of various SPS sidelink multicast configuration parameters (e.g., stored by some or all of the UEs in UE 115r-115v), where each configuration may include parameters such as one or more of the following: SPS RNTI, periodicity of sidelink multicast, and / or the maximum number of times a TB can be transmitted for sidelink multicast. According to some examples, the multicast indicator, the SPS indicator, and the configuration index together indicate the set of parameters (e.g., one or more parameters, such as the periodicity of sidelink multicast, or the maximum number of times a TB can be transmitted for sidelink multicast, etc.) associated with the SPS for sidelink multicast.

[0113] Apart from Figure 9 Beyond the functions explicitly shown in the boxes of the example flow 900 illustrated, operations for SPS for sidelink multicast according to some aspects of this disclosure may include further RX UE actions relative to SPS sidelink multicast activation and / or deactivation. For example, the UE may monitor each SCI format 0-1 message and corresponding SCI format 0-2 message and (e.g., using controller / processor 280 that performs SPS sidelink multicast logic) analyze the SCI messages to obtain indications for SPS sidelink multicast. If the SCI format 0-1 message and corresponding SCI format 0-2 message indicate group SPS activation / deactivation and the group destination ID (e.g., the destination group identifier of the SCI format 0-2 message, SL-SPS-group-RNTI, etc.) indicates that the UE is an RX UE of the target group for SPS sidelink multicast, then the UE may perform various operations for activation and / or SPS sidelink multicast operations.

[0114] According to some aspects of this disclosure, if the received SCI format 0-1 message and corresponding SCI format 0-2 message pair are determined to indicate that the SPS configuration is disabled, the sidelink RX UE can cancel the periodic procedure for the SPS configuration and stop periodic monitoring of the corresponding PSSCH channel. However, if the received SCI format 0-1 message and corresponding SCI format 0-2 message pair are determined to indicate that the SPS configuration is active, the sidelink RX UE can store the SPS configuration and these two SCIs. For example, if the configuration index indicates that the SPS configuration activation is new, the periodic SPS procedure can be added to any existing procedures stored by the sidelink RX UE. If the configuration index indicates that the SPS configuration activation is a reactivation or update of an existing SPS configuration, the corresponding existing periodic SPS procedure can be updated by the sidelink RX UE. Furthermore, the sidelink RX UE can decode the corresponding PSSCH data.

[0115] A sidelink RX UE operating according to the SPS configuration of SPS for sidelink multicast can receive and decode data from the PSSCH channel and periodically send ACK / NACK on the PSFCH according to the stored SPS configuration and SCI. Current V2X interface protocols provide a NACK-only option for feedback on the PSFCH, as well as ACK and NACK options. For any PSSCH data accompanied by an SCI (e.g., SCI format 0-1 messages and / or SCI format 0-2 messages), the sidelink RX UE operating according to some aspects of this disclosure implements ACK and NACK for feedback on the PSFCH if activation / reactivation is not complete. Accordingly, the sidelink RX UE can operate to send ACK / NACK on the PSFCH regardless of the NACK-only option for decoding PSSCH multicast data. Even with the NACK-only option, the SPS configuration activation process can still be determined to be incomplete according to some aspects of this disclosure (e.g., if each data is correctly received, the SPS configuration activation process can be additionally determined to be incomplete).

[0116] In the operation of SPS sidelink multicast in some aspects of this disclosure, the sidelink RX UE can continue to receive and decode data from the PSSCH channel without accompanying corresponding SCI format 0-1 and / or SCI format 0-2 messages. For example, if no SCI format 0-1 and SCI format 0-2 message pairs containing group SPS information related to the stored SPS configuration are received, the stored SPS configuration and SCI remain valid and the sidelink RX UE continues to periodically receive data from the corresponding PSSCH.

[0117] The SPS sidelink multicast implemented according to some aspects of this disclosure provides robust and resilient delivery of multicast data. Accordingly, the technology for retransmitting multicast data can be implemented by the sidelink TX UE and / or the sidelink RX UE. The sidelink TX UE can (e.g., using a controller / processor 280 that executes the SPS sidelink multicast logic) determine whether multicast data (e.g., previously transmitted TB of data) should be retransmitted based on various considerations.

[0118] A sidelink TX UE may retransmit multicast data, for example, in response to receiving a NACK (e.g., via PSFCH) from a sidelink RX UE in an SPS sidelink multicast group. According to some aspects of this disclosure, a first UE (e.g., UE115r of CPE communication configuration 700) may determine to retransmit multicast TB for sidelink multicast based on receiving a NACK for PSSCH multicast data transmission for sidelink multicast from a sidelink RX UE in an SPS sidelink multicast group (e.g., UEs in UEs 115s-115v of a target group in groups 701-703). This retransmission technique may be utilized with respect to a NACK-only option for feedback, as well as an ACK and NACK option.

[0119] As another example, a sidelink TX UE may retransmit multicast data in response to not yet receiving an ACK (e.g., via PSFCH) from any sidelink RX UE in an SPS sidelink multicast group. According to some aspects of this disclosure, a first UE (e.g., UE115r) may determine to retransmit multicast TB for sidelink multicast based on the failure to receive an ACK for PSSCH multicast data transmission for sidelink multicast from a sidelink RX UE in an SPS sidelink multicast group (e.g., UEs in UE115s-115v of a target group in groups 701-703). This retransmission technique may be utilized with respect to ACK and NACK options for feedback.

[0120] According to various aspects of this disclosure, a sidelink TX UE can allocate resources for retransmitting SPS sidelink multicast data. For example, when providing dynamic retransmission of SPS sidelink multicast data, the sidelink TX UE can allocate resources for retransmitting SPS sidelink multicast data using the same HARQ ID as the original transmission of the data (e.g., as if the retransmission carries new data). Accordingly, according to some aspects of this disclosure, a first UE (e.g., UE 115r) can allocate resources for retransmitting a multicast TB for sidelink multicast and retransmit the multicast TB using the same HARQ procedure ID as the original transmission for the multicast TB. According to some aspects of this disclosure, both SCI format 0-1 messages and SCI format 0-2 messages (e.g., carrying SPS indicators, configuration indexes, etc.) accompany the retransmission of SPS sidelink multicast data. Fields within the SCI format 0-1 message and / or SCI format 0-2 message can, for example, indicate that the PSSCH contains retransmitted data. For example, a TX UE may transmit SCI format 0-1 and SCI format 0-2 messages carrying an SPS indicator and a configuration index, wherein the new data indicator field may be set to 1 (e.g., to indicate that the SCI is not used for activation / deactivation but for retransmission), and the HARQ procedure ID field is set to the HARQ procedure ID of the SPS. Accordingly, the TB for retransmitting SPS sidelink multicast may include a first UE (e.g., UE 115r) transmitting a second SCI format 0-1 message for sidelink multicast, transmitting a second SCI format 0-2 message for sidelink multicast, and retransmitting PSSCH multicast data for sidelink multicast. The second SCI format 0-1 message and / or the second SCI format 0-2 message may carry SPS control signaling for sidelink multicast (e.g., SPS indicator, configuration index, etc.). Additionally or alternatively, the second SCI format 0-1 message, the second SCI format 0-2 message, or both may include one or more fields indicating that the PSSCH multicast data is retransmitted data for sidelink multicast.

[0121] Figure 10 This is a block diagram illustrating a UE 115 configured according to one aspect of this disclosure. UE 115 includes features such as those for... Figure 2 The structure, hardware, and components described in UE 115. For example, UE 115 includes a controller / processor 280, which operates to execute logical or computer instructions stored in memory 282, and various components that control UE 115 and provide the features and functionality of UE 115. Under the control of controller / processor 280, UE 115 transmits and receives signals via wireless radio 1001a-r and antenna 252a-r. Wireless radio 1001a-r includes various components and hardware, such as... Figure 2The components described in the section on UE 115 include modulator / demodulator 254a-r, MIMO detector 256, receiver processor 258, transmitter processor 264, and TXMIMO processor 266.

[0122] Figure 10The example UE 115 shown includes SPS sidelink multicast logic 1002 and an SPS sidelink multicast configuration parameter database 1003, which can be used to perform functions as described herein with respect to SPS sidelink TX UEs and / or sidelink RX UEs operable to facilitate sidelink multicast. The SPS sidelink multicast logic 1002 may, for example, include program code stored in memory 282, which is executed by the controller / processor 280 to provide the corresponding functionality. In the sidelink TX... In the context of the UE, the SPS sidelink multicast logic 1002 can provide functionality including controlling the following: transmitting a multicast indicator for sidelink multicast, which indicates that the corresponding sidelink transmission is multicast to multiple UEs; transmitting SPS control signaling for sidelink multicast; transmitting a first SCI format 0-1 message for sidelink multicast; transmitting a first SCI format 0-2 message for sidelink multicast; transmitting PSSCH multicast data for sidelink multicast; monitoring feedback messages from each of the multiple UEs; determining that SPS activation for sidelink multicast is incomplete if feedback messages have not yet been received from each of the multiple UEs; and determining that SPS activation for sidelink multicast is incomplete if feedback messages have been received from each of the multiple UEs. PS activation complete; transmit subsequent PSSCH multicast data for sidelink multicast without accompanying SCI format 0-1 messages and SCI format 0-2 messages; transmit subsequent PSSCH multicast data for sidelink multicast with accompanying SCI format 0-1 messages and without accompanying SCI format 0-2 messages; transmit a second SCI format 0-1 message for sidelink multicast; transmit a second SCI format 0-2 message for sidelink multicast; transmit subsequent PSSCH multicast data for sidelink multicast; determine to retransmit multicast TB for sidelink multicast; retransmit multicast TB, etc., because SPS configuration information from SPS sidelink multicast configuration database 1003 can be used, as described above.In the context of a sidelink RXUE, the SPS sidelink multicast logic 1002 can provide functionality including controlling the following: receiving a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission performed by a first UE is multicast to multiple UEs; receiving SPS control signaling for sidelink multicast; receiving a first SCI format 0-1 message for sidelink multicast; receiving a first SCI format 0-2 message for sidelink multicast; determining whether the first SCI format 0-1 message and the first SCI format 0-2 message correspond to a sidelink transmission for sidelink multicast to multiple UEs; analyzing the first SCI format 0-1 message and the first SCI format 0-2 message for sidelink multicast; and analyzing the first SCI format 0-2 message for sidelink multicast to multiple UEs. An SCI format 0-1 message, a first SCI format 0-2 message, or both are used to obtain an activation status indicator indicating the activation or deactivation of the SPS for the sidelink multicast; the PSSCH multicast data for the sidelink multicast is decoded; ACK / NACK is transmitted for the PSSCH multicast data; configuration parameters for the SPS are stored; and the SPS for the sidelink multicast is determined, at least in part, based on a configuration index, whether it is new or updated, etc., because SPS configuration information from the SPS sidelink multicast configuration database 1003 can be utilized, as described above.

[0123] In some examples of the methods, apparatuses, and articles of art described herein, various aspects of the techniques for SPS of sidelink multicast can be implemented according to diverse combinations consistent with the concepts described herein. Non-limiting examples of combinations of some aspects of the techniques for SPS of sidelink multicast are illustrated in the example clauses below.

[0124] 1. A method, apparatus, and article of manufacture for wireless communication may provide: a multicast indicator transmitted by a first UE for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission is multicast to multiple UEs; and an SPS control signaling transmitted by the first UE for the sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0125] 2. The method, apparatus, and article of manufacture as described in Clause 1, wherein the multicast indicator is transmitted at least in part via a field of an SCI format 0-1 message or a field of an SCI format 0-2 message, and wherein the SPS indicator is transmitted at least in part via one or more fields of an SCI format 0-1 message.

[0126] 3. The method, apparatus, and article of manufacture of any of Clauses 1-2, wherein the SPS indicator is transmitted at least in part by scrambling the CRC of the SCI format 0-1 message using a shared SL-SPS-RNTI shared by all UEs communicating with the first UE on a side link.

[0127] 4. The method, apparatus, and article of any of Clauses 1-2, wherein the ensemble indicator and the SPS indicator are jointly transmitted, at least in part, by scrambling the CRC of the SCI format 0-1 message using an SL-SPS-group-RNTI for a group of ensemble receiver UEs including the plurality of UEs.

[0128] 5. Methods, apparatus and articles of manufacture as described in any of Clauses 1-4, wherein the SPS indicator is transmitted at least in part via one or more fields of an SCI format 0-1 message.

[0129] 6. Methods, apparatus and articles of manufacture as described in Clause 5, wherein the CRC included in the fields of an SCI format 0-1 message is scrambled using an SPS RNTI that provides an SPS indicator.

[0130] 7. The method, apparatus and article of manufacture as described in Clause 6, wherein the SPS RNTI is a common SL-SPS-RNTI shared by all UEs communicating with the first UE on a side link.

[0131] 8. The methods, apparatus and articles of manufacture as described in Clause 7, wherein the shared SL-SPS-RNTI indicates that the SCI format 0-1 message and the corresponding SCI format 0-2 message contain SPS information for sidelink multicast.

[0132] 9. The method, apparatus and article of manufacture as described in Clause 6, wherein the SPS RNTI is an SL-SPS-group-RNTI for a group of multicast receiving UEs including the plurality of UEs.

[0133] 10. The method, apparatus and article of article 9, wherein when the group indicated by SL-SPS-group-RNTI is consistent with the group indicated in the SCI format 0-2 message corresponding to the SCI format 0-1 message, the message destination group identifier and zone identifier in the corresponding SCI format 0-2 message are made available for purposes other than the destination group identifier and zone identifier.

[0134] 11. The method, apparatus, and article of manufacture of any of the provisions 5-10, wherein the field of the SCI format 0-1 message is defined to provide an SPS indicator for indicating the presence of SPS information in the SCI format 0-1 message and the corresponding SCI format 0-2 message.

[0135] 12. The method, apparatus, and article of any of the provisions 1-11, wherein the activation status indicator indicates the activation or deactivation of the SPS for the crosslink multicast.

[0136] 13. The method, apparatus, and article of any of the provisions 1-12, wherein the activation status indicator is transmitted at least in part via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof.

[0137] 14. The method, apparatus, and article of manufacture as described in Clause 13, wherein a combination of the contents of at least one field of an SCI format 0-1 message and at least one field of an SCI format 0-2 message provides an activation status indicator.

[0138] 15. The method, apparatus and article of manufacture as described in Clause 14, wherein the content of at least one field of an SCI format 0-1 message includes the content of an indicator group SPS, and the content of at least one field of an SCI format 0-2 message includes a new data indicator.

[0139] 16. The method, apparatus, and article of manufacture as described in Clause 15, wherein an activation status indicator indicates activation of the SPS for the sidelink multicast when the content of at least one field of the SCI format 0-1 message indicates group SPS, the content of at least one field of the SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for the sidelink multicast is feasible, and wherein an activation status indicator indicates deactivation of the SPS for the sidelink multicast when the content of at least one field of the SCI format 0-1 message indicates group SPS, the content of at least one field of the SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for the sidelink multicast is set to all 0.

[0140] 17. The method, apparatus, and article of any of the provisions 13-16, wherein a field of an SCI format 0-1 message defined for indicating the activation state of an SPS of a crosslink cascade or a field of an SCI format 0-2 message defined for indicating the activation state provides an activation state indicator.

[0141] 18. A method, apparatus, or article of manufacture as described in any of Clauses 1-17, wherein the configuration index is transmitted at least in part via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof.

[0142] 19. Methods, apparatus and articles of manufacture as described in Clause 18, wherein the configuration index is transmitted at least in part via a field of the instruction group SPS of an SCI format 0-1 message or an SCI format 0-2 message.

[0143] 20. Methods, apparatus and articles of manufacture as described in Clause 18, wherein a combination of the contents of the SPS field of the SCI format 0-1 message and the contents of the HARQ process identifier field specifying the index value provides a configuration index.

[0144] 21. The method, apparatus, and article of manufacture as described in Clause 18, wherein a field of an SCI format 0-1 message is defined as indicating an index value for a configuration index, or a field of an SCI format 0-2 message is defined as indicating that the index value provides a configuration index.

[0145] 22. A method, apparatus, or article of manufacture of any of the provisions 1-21, wherein the multicast indicator, the SPS indicator, and the configuration index together indicate a set of parameters associated with the SPS of the sidelink multicast, the set of parameters including the periodicity of the sidelink multicast or the maximum number of times a TB for the sidelink multicast can be transmitted.

[0146] 23. A method, apparatus, or article of manufacture as described in any of Clauses 1-22, wherein the configuration index provides an index for one or more parameters in a parameter set, which includes one or more of the following: SPS RNTI, the periodicity of sidelink multicast, or the maximum number of times a TB can be transmitted for sidelink multicast.

[0147] 24. The method, apparatus, and article of manufacture of any of the provisions 1-23 further provide: transmitting a first SCI format 0-1 message for sidelink multicast by a first UE; transmitting a first SCI format 0-2 message for sidelink multicast by the first UE, wherein SPS control signaling for sidelink multicast transmitted by the first UE is included in the SCI format 0-1 message, the SCI format 0-2 message, or a combination thereof; and transmitting PSSCH multicast data for sidelink multicast.

[0148] 25. The method, apparatus, and article of manufacture of any of the provisions 1-24, wherein the activation status indicator indicates the activation of the SPS of the cross-link multicast, and further provides: monitoring feedback messages from each of the plurality of UEs; and determining that the activation of the SPS of the cross-link multicast is incomplete if no feedback message has been received from each of the plurality of UEs, or determining that the activation of the SPS of the cross-link multicast is complete if a feedback message has been received from each of the plurality of UEs.

[0149] 26. The method, apparatus, and article of manufacture as described in Clause 25, wherein, when it is determined that the activation of the SPS for the sidelink multicast is not completed, subsequent PSSCH multicast data transmission for the sidelink multicast is accompanied by a first SCI format 0-1 message and a second SCI format 0-2 message.

[0150] 27. The method, apparatus, and article of manufacture as described in Clause 25, wherein, when a feedback message has been received from each of the plurality of UEs and the activation of the SPS for the sidelink multicast is completed, subsequent PSSCH multicast data transmission for the sidelink multicast is not accompanied by an SCI or is accompanied only by an SCI format 0-1 message.

[0151] 28. The method, apparatus, and article of manufacture as described in Clause 25, wherein when it is determined that the activation of the SPS for the sidelink multicast is complete, subsequent PSSCH multicast data transmission for the sidelink multicast is not accompanied by an SCI format 0-1 message, an SCI format 0-2 message, or both.

[0152] 29. The method, apparatus, and article of manufacture of Clause 28, wherein the sidelink resources for sidelink multicast are scheduled by a base station communicating with the first UE, and further providing: determining that the content of an SCI format 0-1 message and an SCI format 0-2 message associated with an instance of subsequent PSSCH multicast data transmission are equivalent to the content of a corresponding one of the first SCI format 0-1 message and the first SCI format 0-2 message; and instances in which the first UE transmits subsequent PSSCH multicast data transmission for sidelink multicast without being accompanied by an SCI format 0-1 message and an SCI format 0-2 message.

[0153] 30. The method, apparatus, and article of manufacture of Clause 28, wherein the sidelink resources for sidelink multicast are scheduled by a first UE, and further providing: determining that the content of an SCI format 0-1 message and an SCI format 0-2 message associated with an instance of subsequent PSSCH multicast data transmission are equivalent to the content of a corresponding one of the first SCI format 0-1 message and the first SCI format 0-2 message; and instances in which subsequent PSSCH multicast data transmission for sidelink multicast is transmitted by the first UE accompanied by an SCI format 0-1 message but not accompanied by an SCI format 0-2 message.

[0154] 31. The method, apparatus, and article of manufacture as described in Clause 24, wherein an activation status indicator indicates activation of the SPS for sidelink multicast, and further provides: a first UE transmitting a second SCI format 0-1 message for sidelink multicast; a first UE transmitting a second SCI format 0-2 message for sidelink multicast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or both include content updated relative to the first SCI format 0-1 message, the first SPS format 0-2 message, or both, for reactivating the SPS for sidelink multicast using a different SPS configuration; and transmitting subsequent PSSCH multicast data for sidelink multicast.

[0155] 32. The method, apparatus and article of manufacture as described in Clause 24 further provide: a first UE transmitting a second SCI format 0-1 message for sidelink multicast; and a first UE transmitting a second SCI format 0-2 message for sidelink multicast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message or a combination thereof provides an activation status indicator indicating the deactivation of the SPS for sidelink multicast.

[0156] 33. The method, apparatus, and article of manufacture of any of the provisions 1-32 further provide that: the first UE determines, based on receiving a NACK from one of the plurality of UEs, for the PSSCH multicast data transmission for sidelink multicast, that the multicast TB to be retransmitted is to be used for sidelink multicast.

[0157] 34. The method, apparatus, and article of manufacture of any of the provisions 1-33 further provide that: the first UE determines to retransmit the multicast TB for sidelink multicast based on the fact that it has failed to receive an ACK for PSSCH multicast data transmission for sidelink multicast from one of the plurality of UEs.

[0158] 35. The method, apparatus, and article of manufacture of any of the provisions 1-34, further comprising: allocating resources by a first UE for retransmitting a multicast TB for sidelink multicast; retransmitting the multicast TB by the first UE, wherein the same HARQ procedure identifier of the original transmission for the multicast TB is used for retransmitting the multicast TB, and wherein retransmitting the TB includes: transmitting a second SCI format 0-1 message for sidelink multicast by the first UE, transmitting a second SCI format 0-2 message for sidelink multicast by the first UE, wherein the second SCI format 0-1 message and the second SCI format 0-2 message carry SPS control signaling for sidelink multicast; and retransmitting PSSCH multicast data for sidelink multicast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or both include one or more fields indicating that the PSSCH multicast data is retransmitted data for sidelink multicast.

[0159] 36. A method, apparatus, and article of manufacture for wireless communication may provide: receiving, by one of a plurality of UEs in communication with a first UE, a multicast indicator for sidelink multicast, the multicast indicator indicating that a corresponding sidelink transmission performed by the first UE is multicast to the plurality of UEs; and receiving, by the UE of the plurality of UEs, SPS control signaling for sidelink multicast, the SPS control signaling including an SPS indicator, an activation status indicator, and a configuration index.

[0160] 37. The method, apparatus, and article of manufacture as described in Clause 36, wherein the multicast indicator is received at least in part via a field of an SCI format 0-1 message or a field of an SCI format 0-2 message, and wherein the SPS indicator is received at least in part via one or more fields of an SCI format 0-1 message.

[0161] 38. The method, apparatus, and article of any of Clauses 36-37, wherein the SPS indicator is received at least in part by a CRC of an SCI format 0-1 message, the CRC being scrambled using a common SL-SPS-RNTI shared by all UEs communicating with the first UE on a sidelink.

[0162] 39. The method, apparatus, and article of any of Clauses 36-37, wherein the multicast indicator and the SPS indicator are received jointly, at least in part, by a CRC of an SCI format 0-1 message, the CRC being scrambled using an SL-SPS-group-RNTI for a group of multicast receiving UEs including the plurality of UEs.

[0163] 40. A method, apparatus, or article of manufacture as described in any of Clauses 36-39, wherein the SPS indicator is received at least in part via one or more fields of an SCI format 0-1 message.

[0164] 41. Methods, apparatus and articles of manufacture as described in Clause 40, wherein the CRC included in the fields of an SCI format 0-1 message is scrambled using an SPS RNTI that provides an SPS indicator.

[0165] 42. The method, apparatus and article of manufacture as described in Clause 41, wherein the SPS RNTI is a common SL-SPS-RNTI shared by all UEs in side-link communication with the first UE.

[0166] 43. The method, apparatus and article of manufacture as described in Clause 42, wherein the shared SL-SPS-RNTI indicates that the SCI format 0-1 message and the corresponding SCI format 0-2 message contain SPS information for sidelink multicast.

[0167] 44. The method, apparatus and article of manufacture as described in Clause 41, wherein the SPS RNTI is an SL-SPS-group-RNTI for a group of multicast receiving UEs including the plurality of UEs.

[0168] 45. The method, apparatus and article of article 44, wherein when the group indicated by SL-SPS-group-RNTI is the same as the group indicated in the SCI format 0-2 message corresponding to the SCI format 0-1 message, the message destination group identifier and zone identifier in the corresponding SCI format 0-2 message are used for purposes other than the destination group identifier and zone identifier.

[0169] 46. ​​Any method, apparatus, or article of manufacture as described in any of Clauses 40-45, wherein the field of the SCI Format 0-1 message is defined to provide an SPS indicator for indicating the presence of SPS information in the SCI Format 0-1 message and the corresponding SCI Format 0-2 message.

[0170] 47. A method, apparatus, or article of manufacture as described in any of Clauses 40-46, wherein an activation status indicator indicates the activation or deactivation of the SPS for the crosslink multicast.

[0171] 48. A method, apparatus, or article of manufacture as described in any of Clauses 40-47, wherein the activation status indicator is received at least in part via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof.

[0172] 49. The method, apparatus and article of manufacture as described in Clause 48, wherein a combination of the contents of at least one field of an SCI format 0-1 message and at least one field of an SCI format 0-2 message provides an activation status indicator.

[0173] 50. The method, apparatus, and article of manufacture as described in Clause 49, wherein the content of at least one field of an SCI format 0-1 message includes the content of an indicator group SPS, and the content of at least one field of an SCI format 0-2 message includes a new data indicator.

[0174] 51. The method, apparatus, and article of manufacture of Clause 50, wherein an activation status indicator indicates activation of the SPS for the sidelink multicast when the content of at least one field of the SCI format 0-1 message indicates group SPS, the content of at least one field of the SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for the sidelink multicast is feasible, and wherein an activation status indicator indicates deactivation of the SPS for the sidelink multicast when the content of at least one field of the SCI format 0-1 message indicates group SPS, the content of at least one field of the SCI format 0-2 message includes a new data field value of 0, and frequency and time resource allocation for the sidelink multicast is set to all 0.

[0175] 52. The method, apparatus, and article of any of the provisions 48-51, wherein a field of an SCI format 0-1 message defined for indicating the activation state of an SPS of a crosslink multicast or a field of an SCI format 0-2 message defined for indicating the activation state provides an activation state indicator.

[0176] 53. Methods, apparatus and articles of manufacture as described in clauses 36-52, wherein the configuration index is received at least in part via one or more fields of an SCI format 0-1 message, one or more fields of an SCI format 0-2 message, or a combination thereof.

[0177] 54. The method, apparatus, and article of manufacture as described in Clause 53, wherein the configuration index is received at least in part via an SCI format 0-1 message or an SCI format 0-2 message of the instruction group SPS.

[0178] 55. Methods, apparatus and articles of manufacture as described in Clause 53, wherein a combination of the contents of an SCI format 0-1 message indicating the group SPS and a HARQ process identifier field specifying an index value provides a configuration index.

[0179] 56. The method, apparatus, and article of manufacture as described in Clause 53, wherein a field of an SCI format 0-1 message is defined as indicating an index value for configuring an index, or a field of an SCI format 0-2 message is defined as indicating that the index value provides a configuration index.

[0180] 57. A method, apparatus, or article of manufacture as described in any of clauses 36-56, wherein the multicast indicator, the SPS indicator, and the configuration index together indicate a set of parameters associated with the SPS of the sidelink multicast, the set of parameters including the periodicity of the sidelink multicast or the maximum number of times a TB for the sidelink multicast can be transmitted.

[0181] 58. A method, apparatus, or article of manufacture as described in any of clauses 36-56, wherein the configuration index provides an index for one or more parameters in a parameter set, which includes one or more of the following: SPS RNTI, periodicity of sidelink multicast, or the maximum number of times a TB can be transmitted for sidelink multicast.

[0182] 59. The method, apparatus, and article of manufacture of any of the provisions 36-58 further provide: receiving a first SCI format 0-1 message for sidelink multicast by one of the plurality of UEs; receiving a first SCI format 0-2 message for sidelink multicast by one of the plurality of UEs; determining whether the first SCI format 0-1 message and the first SCI format 0-2 message correspond to a sidelink transmission for sidelink multicast to the plurality of UEs; and analyzing the first SCI format 0-1 message, the first SCI format 0-2 message, or both, to obtain an activation status indicator indicating activation or deactivation of SPS for sidelink multicast.

[0183] 60. The method, apparatus, and article of manufacture as described in Clause 59, wherein an activation status indicator indicates activation of SPS for sidelink multicast, and further provides that: the UE among the plurality of UEs decodes the PSSCH multicast data for sidelink multicast.

[0184] 61. The methods, apparatus and articles of manufacture of any of the provisions 59-60 are further provided with: the UE of the plurality of UEs transmitting an ACK or NACK for decoding PSSCH multicast data regardless of the NACK-only option for decoding PSSCH multicast data.

[0185] 62. The method, apparatus, and article of manufacture of any of the provisions 59-60 further provide: storing configuration parameters for SPS, the content of a first SCI format 0-1 message, and the content of a first SCI format 0-2 message by the UE among the plurality of UEs; receiving PSSCH multicast data by the UE among the plurality of UEs according to SPS; and transmitting ACK or NACK for PSSCH multicast data by the UE among the plurality of UEs according to the SPS configuration parameters and the content of the first SCI format 0-1 message and the first SCI format 0-2 message stored by the UE among the plurality of UEs.

[0186] 63. The method, apparatus, and article of manufacture of any of the provisions 36-62 further provide that: the UE of the plurality of UEs determines, at least in part, that the SPS broadcast on the opposite link is new based on a configuration index; and the UE of the plurality of UEs stores the periodicity of the SPS in an SPS periodicity database.

[0187] 64. The method, apparatus, and article of manufacture of any of the provisions 36-63 further provide: determining, at least in part, by one of the plurality of UEs, that the SPS broadcast on the opposite link is a reactivation of the SPS based on a configuration index; and updating the periodicity of the SPS in the SPS periodicity procedure database by one of the plurality of UEs.

[0188] 65. The method, apparatus, and article of any of the provisions 36-64, wherein the activation status indicator indicates the deactivation of the SPS for sidelink multicast, and further provides: the periodic procedure of canceling the SPS by the UE among the plurality of UEs, wherein the UE among the plurality of UEs stops the periodic monitoring of the PSSCH for finding data for sidelink multicast.

[0189] 66. The method, apparatus, and article of manufacture of any of the provisions 59-65, wherein the value of the activation state indicator indicates activation of SPS for sidelink multicast, and further comprising: receiving a second SCI format 0-1 message for sidelink multicast by the UE among the plurality of UEs; receiving a second SCI format 0-2 message for sidelink multicast by the UE among the plurality of UEs; determining, at least in part, that a periodic procedure for SPS remains valid based on the failure of the second SCI format 0-1 message and the second SCI format 0-2 message to include SPS information for sidelink multicast by the UE among the plurality of UEs; and monitoring the PSSCH according to the periodic procedure for SPS to look for sidelink multicast data.

[0190] Those skilled in the art will understand that information and signals can be represented using any of a variety of different techniques and skills. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or light particles, or any combination thereof.

[0191] The components, functional blocks, and modules described in this document (e.g., Figure 2 The components, functional blocks, and modules (in this document) may include processors, electronic devices, hardware devices, electronic components, logic circuits, memory, software code, firmware code, etc., or any combination thereof. Furthermore, the SPS-related features for crosslink multicast discussed herein may be implemented via dedicated processor circuitry, via executable instructions, and / or combinations thereof.

[0192] Those skilled in the art will further appreciate that, in conjunction with the various illustrative logic blocks, modules, circuits, and algorithmic steps disclosed herein (e.g., Figure 8 and 9The logic blocks (in this document) can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above in their functional form. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art may implement the described functionality in different ways for each specific application, but such implementation decisions should not be construed as departing from the scope of this disclosure. Those skilled in the art will also readily recognize that the order or combination of components, methods, or interactions described herein are merely examples and that components, methods, or interactions of various aspects of this disclosure may be combined or performed in ways other than those explained and described herein.

[0193] The various illustrative logic blocks, modules, and circuits described herein can be implemented or executed using a general-purpose processor, digital signal processor (DSP), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. The general-purpose processor may be a microprocessor, but in alternatives, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0194] The steps of the methods or algorithms described herein can be implemented directly in hardware, in a software module executed by a processor, or a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0195] In one or more exemplary designs, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one location to another. A computer-readable storage medium may be any available medium accessible to a general-purpose or special-purpose computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Furthermore, a connection may also be appropriately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL), then the coaxial cable, fiber optic cable, twisted pair, or DSL is included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), hard disks, solid-state drives (SSDs), and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0196] As used herein (including in the claims), the term “and / or” in a list of two or more items means that any one of the listed items may be used alone, or any combination of two or more listed items may be used. For example, if a composition is described as containing components A, B, and / or C, then the composition may contain only A; only B; only C; a combination of A and B; a combination of A and C; a combination of B and C; or a combination of A, B, and C. Moreover, as used herein (including in the claims), the “or” in a list of items followed by “at least one of” indicates a disjunctive list, such that a list such as “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) or any combination thereof.

[0197] The prior description of this disclosure is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other variations without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not intended to be limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method of wireless communication, comprising: transmitting, by a first user equipment (UE), a groupcast indicator for a sidelink groupcast, the groupcast indicator indicating that a corresponding sidelink transmission is groupcasted to a plurality of UEs; and transmitting, by the first UE, semi-persistent scheduling (SPS) control signaling for the sidelink groupcast, the SPS control signaling including an SPS indicator indicating a presence of group SPS information, an activation state indicator indicating an activation of SPS for the sidelink groupcast or a deactivation of the SPS for the sidelink groupcast, and a configuration index providing an index for one or more parameters in a numerology for the SPS for the sidelink groupcast.

2. The method of claim 1, wherein, the groupcast indicator is transmitted at least in part via a field of a sidelink control information (SCI) format 0-1 message or a field of a SCI format 0-2 message, and wherein the SPS indicator is transmitted at least in part via one or more fields of a SCI format 0-1 message.

3. The method of claim 1, wherein, the SPS indicator is transmitted at least in part by scrambling a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message using a common sidelink SPS radio network temporary identifier (SL-SPS-RNTI) that is common to all UEs in sidelink communication with the first UE.

4. The method of claim 1, wherein, the groupcast indicator and the SPS indicator are jointly transmitted at least in part by scrambling a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message using a sidelink SPS group-specific radio network temporary identifier (SL-SPS-group-RNTI) for a group of groupcast receiver UEs including the plurality of UEs.

5. The method of claim 1, wherein, the activation state indicator is transmitted at least in part via a combination of contents of at least one field of a sidelink control information (SCI) format 0-1 message and at least one field of a SCI format 0-2 message.

6. The method of claim 1, wherein, the configuration index is transmitted at least in part via a group SPS field of a sidelink control information (SCI) format 0-1 message or a SCI format 0-2 message.

7. The method of claim 1, wherein, the groupcast indicator, the SPS indicator, and the configuration index together indicate a numerology associated with SPS for the sidelink groupcast, the numerology including a periodicity of the sidelink groupcast or a maximum number of times a transport block (TB) for the sidelink groupcast can be transmitted.

8. The method of claim 1, wherein, the activation state indicator indicates an activation of SPS for the sidelink groupcast, and wherein a subsequent physical sidelink shared channel (PSSCH) groupcast data transmission for the sidelink groupcast is accompanied by a first sidelink control information (SCI) format 0-1 message and a second SCI format 0-2 message when a feedback message has not been received from each of the plurality of UEs and the activation of SPS for the sidelink groupcast is not complete.

9. The method of claim 1, wherein, The activation status indicator indicates an activation of a SPS for the sidelink groupcast, and wherein a subsequent physical sidelink shared channel (PSSCH) groupcast data transmission for the sidelink groupcast is accompanied by no sidelink control information (SCI) or only a SCI format 0-1 message when feedback messages have been received from each of the plurality of UEs and the activation of the SPS for the sidelink groupcast is complete.

10. The method of claim 1, further comprising: allocating, by the first UE, resources for retransmission of a groupcast transport block (TB) for the sidelink groupcast; retransmitting, by the first UE, the groupcast TB, wherein a same hybrid automatic repeat request (HARQ) process identification for an original transmission of the groupcast TB is used for retransmission of the groupcast TB, and wherein retransmitting the TB comprises: transmitting, by the first UE, a second SCI format 0-1 message for the sidelink groupcast; transmitting, by the first UE, a second SCI format 0-2 message for the sidelink groupcast, wherein the second SCI format 0-1 message and the second SCI format 0-2 message carry the SPS control signaling for the sidelink groupcast; and retransmitting physical sidelink shared channel (PSSCH) groupcast data for the sidelink groupcast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or both include one or more fields indicating that the PSSCH groupcast data is retransmitted data for the sidelink groupcast.

11. An apparatus configured for wireless communication, the apparatus comprising: at least one processor; and a memory in electronic communication with the at least one processor, wherein the at least one processor is configured to cause the apparatus to: transmit a groupcast indicator for a sidelink groupcast, the groupcast indicator indicating that a corresponding sidelink transmission by a first user equipment (UE) is groupcast to a plurality of UEs; and transmit semi-persistent scheduling (SPS) control signaling for the sidelink groupcast, the SPS control signaling including an SPS indicator indicating a presence of group SPS information, an activation status indicator indicating an activation of a SPS for the sidelink groupcast or a deactivation of the SPS for the sidelink groupcast, and a configuration index providing an index to one or more parameters of a numerology for the SPS for the sidelink groupcast.

12. The apparatus of claim 11, wherein, the groupcast indicator is transmitted at least in part via a field of a sidelink control information (SCI) format 0-1 message or a field of a SCI format 0-2 message, and wherein the SPS indicator is transmitted at least in part via one or more fields of a SCI format 0-1 message.

13. The apparatus of claim 11, wherein, the SPS indicator is transmitted at least in part by scrambling a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message using a common sidelink SPS radio network temporary identifier (SL-SPS-RNTI) that is common to all UEs in sidelink communication with the first UE.

14. The apparatus of claim 11, wherein, The groupcast indicator and the SPS indicator are jointly transmitted at least in part by scrambling a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message using a sidelink SPS group radio network temporary identifier (SL-SPS-group-RNTI) for a group of groupcast receiver UEs including the plurality of UEs.

15. The apparatus of claim 11, wherein, The activation status indicator is transmitted at least in part via a combination of contents of at least one field of a sidelink control information (SCI) format 0-1 message and at least one field of a SCI format 0-2 message.

16. The apparatus of claim 11, wherein, The configuration index is transmitted at least in part via a field of a sidelink control information (SCI) format 0-1 message or a SCI format 0-2 message indicating a group SPS.

17. The apparatus of claim 11, wherein, The groupcast indicator, the SPS indicator, and the configuration index together indicate a set of parameters associated with the SPS for the sidelink groupcast, the set of parameters including a periodicity of the sidelink groupcast or a maximum number of times a transport block (TB) for the sidelink groupcast can be transmitted.

18. The apparatus of claim 11, wherein, The activation status indicator indicates an activation of the SPS for the sidelink groupcast, wherein, when a feedback message has not been received from each of the plurality of UEs and the activation of the SPS for the sidelink groupcast is not complete, a subsequent physical sidelink shared channel (PSSCH) groupcast data transmission for the sidelink groupcast is accompanied by a first sidelink control information (SCI) format 0-1 message and a second SCI format 0-2 message, and wherein, when a feedback message has been received from each of the plurality of UEs and the activation of the SPS for the sidelink groupcast is complete, a subsequent PSSCH groupcast data transmission for the sidelink groupcast is not accompanied by SCI or is accompanied by only a SCI format 0-1 message.

19. The apparatus of claim 11, wherein, The at least one processor is further configured to cause the apparatus to: allocate resources for retransmission of a groupcast transport block (TB) for the sidelink groupcast; retransmit, by the first UE, the groupcast TB, wherein a same hybrid automatic repeat request (HARQ) process identification for an original transmission of the groupcast TB is used for retransmission of the groupcast TB, and wherein the at least one processor configured to retransmit the TB is configured to: transmit a second SCI format 0-1 message for the sidelink groupcast; transmit a second SCI format 0-2 message for the sidelink groupcast, wherein the second SCI format 0-1 message and the second SCI format 0-2 message carry the SPS control signaling for the sidelink groupcast; and retransmit physical sidelink shared channel (PSSCH) groupcast data for the sidelink groupcast, wherein the second SCI format 0-1 message, the second SCI format 0-2 message, or both include one or more fields indicating that the PSSCH groupcast data is retransmitted data for the sidelink groupcast.

20. A method of wireless communication, comprising: receiving, by a user equipment (UE) of a plurality of UEs in communication with a first UE, a groupcast indicator for a sidelink groupcast, the groupcast indicator indicating that a corresponding sidelink transmission by the first UE is groupcasted to the plurality of UEs; and receiving, by the UE of the plurality of UEs, semi-persistent scheduling (SPS) control signaling for the sidelink groupcast, the SPS control signaling including an SPS indicator indicating a presence of group SPS information, an activation state indicator indicating an activation of an SPS for the sidelink groupcast or a deactivation of the SPS for the sidelink groupcast, and a configuration index providing an index for one or more parameters of a numerology for the SPS for the sidelink groupcast.

21. The method of claim 20, wherein, the groupcast indicator is received at least in part via a field of a sidelink control information (SCI) format 0-1 message or a field of a SCI format 0-2 message, and wherein the SPS indicator is received at least in part via one or more fields of a SCI format 0-1 message.

22. The method of claim 20, wherein, the SPS indicator is received at least in part by a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message, the CRC being scrambled using a common sidelink SPS radio network temporary identifier (SL-SPS-RNTI) that is common to all UEs in sidelink communication with the first UE.

23. The method of claim 20, wherein, the groupcast indicator and the SPS indicator are jointly received at least in part by a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message, the CRC being scrambled using a sidelink SPS group-specific radio network temporary identifier (SL-SPS-group-RNTI) for a group of groupcast receiver UEs including the plurality of UEs.

24. The method of claim 20, wherein, the activation state indicator is received at least in part via a combination of contents of at least one field of a sidelink control information (SCI) format 0-1 message and at least one field of a SCI format 0-2 message.

25. The method of claim 20, wherein, the configuration index is received at least in part via a sidelink control information (SCI) format 0-1 message or a SCI format 0-2 message indicating a group SPS.

26. The method of claim 20, wherein, the groupcast indicator, the SPS indicator, and the configuration index together indicate a numerology associated with an SPS for the sidelink groupcast, the numerology including a periodicity of the sidelink groupcast or a maximum number of times a transport block (TB) for the sidelink groupcast can be transmitted.

27. The method of claim 20, further comprising: receiving, by the UE of the plurality of UEs, a first sidelink control information (SCI) format 0-1 message for the sidelink groupcast; and receiving, by the UE of the plurality of UEs, a first SCI format 0-2 message for the sidelink groupcast, wherein the first SCI format 0-1 message and the first SCI format 0-2 message correspond to a sidelink transmission of the sidelink groupcast to the plurality of UEs, and wherein the first SCI format 0-1 message, the first SCI format 0-2 message, or both are configured to provide the activation status indicator that indicates an activation of a SPS for the sidelink groupcast or a deactivation of a SPS for the sidelink groupcast.

28. The method of claim 27, wherein, a value of the activation status indicator indicates the activation of the SPS for the sidelink groupcast, and the method further comprises: receiving, by the UE of the plurality of UEs, a second SCI format 0-1 message for the sidelink groupcast; and receiving, by the UE of the plurality of UEs, a second SCI format 0-2 message for the sidelink groupcast, wherein a periodic procedure of a SPS remains valid based at least in part on the second SCI format 0-1 message and the second SCI format 0-2 message failing to include SPS information for the sidelink groupcast.

29. The method of claim 20, wherein, the activation status indicator indicates the activation of the SPS for the sidelink groupcast, and the method further comprises: decoding, by the UE of the plurality of UEs, physical sidelink shared channel (PSSCH) groupcast data for the sidelink groupcast; and transmitting, by the UE of the plurality of UEs, an acknowledgement (ACK) or a negative acknowledgement (NACK) for decoding the PSSCH groupcast data regardless of a NACK only option for PSSCH groupcast data decoding.

30. An apparatus configured for wireless communication, the apparatus comprising: at least one processor; and memory in electronic communication with the at least one processor, wherein the at least one processor is configured to cause the apparatus to: receive, by a first user equipment (UE) to a plurality of UEs in communication with the first UE, a groupcast indicator for a sidelink groupcast by the first UE to the plurality of UEs, the groupcast indicator indicating that a corresponding sidelink transmission by the first UE is groupcast to the plurality of UEs; and receive, by the first UE, semi-persistent scheduling (SPS) control signaling for the sidelink groupcast, the SPS control signaling including an SPS indicator indicating a presence of group SPS information, an activation status indicator indicating an activation of a SPS for the sidelink groupcast or a deactivation of the SPS for the sidelink groupcast, and a configuration index providing an index for one or more parameters of a numerology for the SPS for the sidelink groupcast.

31. The apparatus of claim 30, wherein, the groupcast indicator is received at least in part via a field of a sidelink control information (SCI) format 0-1 message or a field of a SCI format 0-2 message, and wherein the SPS indicator is received at least in part via one or more fields of a SCI format 0-1 message.

32. The apparatus of claim 30, wherein, The SPS indicator is received at least in part through a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message, the CRC being scrambled using a common sidelink SPS radio network temporary identifier (SL-SPS-RNTI) that is common to all UEs in sidelink communication with the first UE.

33. The apparatus of claim 30, wherein, The groupcast indicator and the SPS indicator are jointly received at least in part through a cyclic redundancy code (CRC) of a sidelink control information (SCI) format 0-1 message, the CRC being scrambled using a sidelink SPS group-specific radio network temporary identifier (SL-SPS-group-RNTI) for a group of groupcast receiver UEs including the plurality of UEs.

34. The apparatus of claim 30, wherein, The activation status indicator is received at least in part via a combination of contents of at least one field of a sidelink control information (SCI) format 0-1 message and at least one field of an SCI format 0-2 message.

35. The apparatus of claim 30, wherein, The configuration index is received at least in part via a field of a sidelink control information (SCI) format 0-1 message or an SCI format 0-2 message that indicates a group SPS.

36. The apparatus of claim 30, wherein, The groupcast indicator, the SPS indicator, and the configuration index together indicate a set of parameters associated with the SPS for the sidelink groupcast, the set of parameters including a periodicity of the sidelink groupcast or a maximum number of times a transport block (TB) for the sidelink groupcast can be transmitted.

37. The apparatus of claim 30, wherein, The at least one processor is further configured to cause the apparatus to: receive a first sidelink control information (SCI) format 0-1 message for the sidelink groupcast; receive a first SCI format 0-2 message for the sidelink groupcast, wherein the first SCI format 0-1 message and the first SCI format 0-2 message correspond to a sidelink transmission of the sidelink groupcast to the plurality of UEs, and wherein the first SCI format 0-1 message, the first SCI format 0-2 message, or both are configured to provide the activation status indicator that indicates an activation of the SPS for the sidelink groupcast or a deactivation of the SPS for the sidelink groupcast.

38. The apparatus of claim 37, wherein, A value of the activation status indicator indicates the activation of the SPS for the sidelink groupcast, and wherein the at least one processor is further configured to cause the apparatus to: receive, by the UE of the plurality of UEs, a second SCI format 0-1 message for the sidelink groupcast; and receive, by the UE of the plurality of UEs, a second SCI format 0-2 message for the sidelink groupcast, wherein a periodicity procedure of the SPS remains valid at least in part based on the second SCI format 0-1 message and the second SCI format 0-2 message failing to include SPS information for the sidelink groupcast.

39. The apparatus of claim 30, wherein, The activation status indicator indicates the activation of the SPS for the sidelink groupcast, and wherein the at least one processor is further configured to cause the apparatus to: decode physical sidelink shared channel (PSSCH) groupcast data for the sidelink groupcast; and transmit an acknowledgement (ACK) or negative acknowledgement (NACK) for decoding the PSSCH groupcast data regardless of a NACK only option for PSSCH groupcast data decoding.

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