WO2021068883A1

WO2021068883A1 - Broadcast group identifier for multicast messages

Info

Publication number: WO2021068883A1
Application number: PCT/CN2020/119948
Authority: WO
Inventors: Min Huang; Chao Wei; Yu Zhang; Sony Akkarakaran
Original assignee: Qualcomm Incorporated
Priority date: 2019-10-12
Filing date: 2020-10-09
Publication date: 2021-04-15
Also published as: WO2021068246A1

Abstract

Methods, systems, and devices for wireless communications are described. A method for wireless communication at a user equipment (UE) may include: receiving, from a base station, at least one group identifier in a broadcast message; monitoring a plurality of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index; identifying, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE; receiving, from the base station, a multicast message associated with the at least one group identifier; and determining that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

Description

BROADCAST GROUP IDENTIFIER FOR MULTICAST MESSAGES

CROSS REFERENCE

The present Application for Patent claims the benefit of PCT Application No. PCT/CN2019/110818 by HUANG et al., entitled “BROADCAST GROUP IDENTIFIER FOR MULTICAST MESSAGES, ” filed October 12, 2019, assigned to the assignee hereof.

BACKGROUND

The following relates generally to wireless communications and more specifically to a broadcast group identifier for multicast messages.

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

Some radio access technologies (RATs) may support broadcast and multicast communications, in which data is transmitted to multiple UEs in a single broadcast or multicast communication. A UE attempting to synchronize with a 5G base station’s cell may use broadcast synchronization signals from the base station to determine preferred beams. In some cases, a synchronized UE may perform a number of communications with a base station before the UE is capable of receiving multicast communications from the base station. Although a UE will eventually be capable of receiving multicast communications from the base station, the multicast preparation may be inefficient due to the large signaling overhead between the base station and each UE to be addressed with a multicast communication.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support a broadcast group identifier for multicast messages. Generally, the described techniques provide for an efficient way of sending identical information to a group of UEs that are associated with a common synchronization signal block (SSB) position or index. A 5G cell search and synchronization procedure may include a UE tuning to a specific frequency to attempt to decode synchronization signals (SSs) (e.g., primary SS (PSS) and secondary SS (SSS) ) . If a UE successfully detects the SSs, then the UE may attempt to decode the physical broadcast channel (PBCH) to determine, for example, system frame number (SFN) , SSB index, raster offset, default downlink numerology, remaining minimum system information (RMSI) configuration, demodulation reference signal (DMRS) location, or some combination thereof. If the UE successfully decodes the PBCH, then the UE may be capable of receiving, from the base station associated with the 5G cell, control and data channels from the base station.

In some cases, the PSS, SSS, and PBCH may form an SSB such as a four symbol SSB. SSBs may be transmitted in a group by forming an SS Burst (e.g., one SSB per beam) that is used during beam sweeping by changing beam direction for each SSB transmission. In some examples, a base station may define multiple candidate positions for SSBs within a radio frame, and this number may correspond to the number of beams radiated in a certain direction. Each SSB may be identified by a unique number, which may be referred to herein as an SSB index, and the identification of which SSB is detected by a UE may depend on where the UE is located (e.g., a UE geographic position) as well as obstacles which affect a transmission path between the base station and the UE. SSBs with the same content may be transmitted repeatedly at a number of positions, also referred to as SSB position, and each SSB position may be associated with an SSB index. The UE may measure one or more SSB positions within an SSB period and identify the best beam for communications between the UE and the base station.

The UE may use the techniques described herein to determine if a multicast message pertains to the UE based on information associated with the SSB position selected by the UE during cell synchronization. More specifically, a base station may assign a group identifier (e.g., a group common radio network temporary identifier (RNTI) ) to the group of UEs that are associated with the common SSB position via broadcast communications. In some examples, a UE may determine a multicast message containing identical information is intended for the UE based on an association between the group identifier and control information corresponding to the multicast message. In other examples, a base station may use a single common RNTI for all SSB positions, and a UE may determine a multicast message containing identical information is intended for the UE when an SSB index identifier is present in control information corresponding to the multicast message.

A method of wireless communication at a UE is described. The method may include receiving, from a base station, at least one group identifier in a broadcast message, monitoring a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index, identifying, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE, receiving, from the base station, a multicast message associated with the at least one group identifier, and determining that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a base station, at least one group identifier in a broadcast message, monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index, identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE, receive, from the base station, a multicast message associated with the at least one group identifier, and determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving, from a base station, at least one group identifier in a broadcast message, monitoring a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index, identifying, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE, receiving, from the base station, a multicast message associated with the at least one group identifier, and determining that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to receive, from a base station, at least one group identifier in a broadcast message, monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index, identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE, receive, from the base station, a multicast message associated with the at least one group identifier, and determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the at least one group identifier in the broadcast message may include operations, features, means, or instructions for receiving a set of group identifiers in the broadcast message, where each group identifier of the set of group identifiers may be associated with at least one synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the at least one group identifier in the broadcast message may include operations, features, means, or instructions for receiving one group identifier in the broadcast message, where the one group identifier may be associated with a set of synchronization signal block indices.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a first group identifier from the broadcast message, the first group identifier being associated with the first synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining that the multicast message pertains to the UE may be based on downlink control information associated with the multicast message being encoded with the first group identifier.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying, based on the monitoring, a second synchronization signal block index for transmissions between the base station and the UE, determining a second group identifier associated with the second synchronization signal block index based on the broadcast message, receiving, from the base station, a second multicast message associated with the second group identifier, and determining that the second multicast message pertains to the UE based on second downlink control information associated with the second multicast message being encoded with the second group identifier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the at least one group identifier in the broadcast message further may include operations, features, means, or instructions for receiving a set of synchronization signal block index identifiers in the broadcast message, where each synchronization signal block index identifier of the set of synchronization signal block index identifiers may be associated with at least one synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a first group identifier from the broadcast message, the first group identifier being associated with a set of synchronization signal block indices that includes the synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying a first synchronization signal block index identifier from the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the multicast message may include operations, features, means, or instructions for receiving downlink control information associated with the multicast message, and determining that the multicast message pertains to the UE based on the downlink control information including the first synchronization signal block index identifier.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for identifying, based on the monitoring, a second synchronization signal block index for transmissions between the base station and the UE, identifying a second synchronization signal block index identifier from the broadcast message, the second synchronization signal block index identifier being associated with the second synchronization signal block index, receiving, from the base station, a second multicast message associated with second downlink control information, the second downlink control information being associated with the first group identifier, and determining that the second multicast message pertains to the UE based on the second downlink control information including the second synchronization signal block index identifier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the multicast message associated with the at least one group identifier may include operations, features, means, or instructions for receiving multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the multicast message associated with the at least one group identifier may include operations, features, means, or instructions for receiving multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the base station, an indication of the first synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the broadcast message includes system information and may be received via a system information block or radio resource configuration signaling.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the at least one group identifier includes a common radio network temporary identifier.

A method of wireless communication at a base station is described. The method may include transmitting, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier, transmitting a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index, and transmitting a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs.

An apparatus for wireless communication at a base station is described. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier, transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index, and transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs.

Another apparatus for wireless communication at a base station is described. The apparatus may include means for transmitting, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier, transmitting a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index, and transmitting a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs.

A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier, transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index, and transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the broadcast message that includes the at least one group identifier may include operations, features, means, or instructions for transmitting a set of group identifiers in the broadcast message, where each group identifier of the set of group identifiers may be associated with at least one synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the broadcast message that includes the at least one group identifier may include operations, features, means, or instructions for transmitting one group identifier in the broadcast message, where the one group identifier may be associated with a set of synchronization signal block indices.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a first multicast message for the set of UEs associated with the first synchronization signal block index, determining a first group identifier included in the broadcast message, the first group identifier being associated with the first synchronization signal block index, encoding first downlink control information associated with the first multicast message with the first group identifier, and transmitting the first multicast message and the first downlink control information, where the first multicast message pertains to the set of UEs based on the first downlink control information being encoded with the first group identifier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the broadcast message that includes the at least one group identifier may include operations, features, means, or instructions for transmitting a set of synchronization signal block index identifiers in the broadcast message, where each synchronization signal block index identifier of the set of synchronization signal block index identifiers may be associated with at least one synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a first multicast message for the set of UEs associated with the first synchronization signal block index, determining a first synchronization signal block index identifier included in the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index, transmitting first downlink control information associated with the first multicast message, where the first downlink control information includes the first synchronization signal block index identifier, and transmitting the first multicast message, where the first multicast message pertains to the set of UEs based on the first downlink control information including the first synchronization signal block index identifier.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the multicast message associated with the at least one group identifier may include operations, features, means, or instructions for transmitting, to the set of UEs, multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the multicast message associated with the at least one group identifier may include operations, features, means, or instructions for transmitting, to the set of UEs, multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving, from each of the set of UEs, an indication of the first synchronization signal block index.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the broadcast message includes system information and may be transmitted via a system information block or radio resource configuration signaling.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communications that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a system for wireless communications that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 3 illustrates an example of a synchronization signal block association map that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a synchronization signal block association map that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIGs. 6 and 7 show block diagrams of devices that support a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 8 shows a block diagram of a communications manager that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 9 shows a diagram of a system including a device that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIGs. 10 and 11 show block diagrams of devices that support a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 12 shows a block diagram of a communications manager that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIG. 13 shows a diagram of a system including a device that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

FIGs. 14 through 19 show flowcharts illustrating methods that support a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some wireless communications systems, a user equipment (UE) may be configured to determine if a multicast message from a base station pertains to the UE based on information associated with a synchronization signal block (SSB) index. Generally, the described techniques provide for an efficient way for a base station to send identical information to a group of UEs that are associated with a common SSB position.

A cell search and synchronization procedure may include a UE tuning to a specific frequency and beam direction to attempt to decode synchronization signals (SSs) (e.g., primary SS (PSS) and secondary SS (SSS) ) . If a UE successfully detects the SSs, then the UE may attempt to decode the physical broadcast channel (PBCH) . If the UE successfully decodes the PBCH, then the UE may be capable of receiving control and data channels from the base station associated with the cell. The SSs and the PBCH may collectively be referred to as an SSB. Because a base station may transmit multiple versions of an SSB in different directions (e.g., along different beams) , the SSBs may be designated by position or index. A UE that successfully detects and decodes the SSs and PBCH of a specific SSB index may identify the SSB index as a preferred SSB position for communications between the UE and the base station.

According to aspects of this disclosure, a base station may assign, via a broadcast message, a group identifier (e.g., a group common radio network temporary identifier (RNTI) ) to one or more UE groups associated with a common SSB position. In some examples, a UE may identify that a multicast message, from the base station, is intended for the UE based on an association between the SSB position of the UE and the group identifier used in the encoding of control information corresponding to the multicast message. In other examples, a base station may use a single common RNTI for every SSB position, and a UE may identify that a multicast message is intended for the UE when an SSB index identifier associated with the SSB position of the UE is present in control information (e.g., downlink control information (DCI) ) corresponding to the multicast message.

The use of a broadcast message to indicate the group identifier (s) and optional SSB index identifiers associated with SSB positions may provide the advantage of reducing the signaling overhead in sending identical data and/or signaling to a group of UEs covered by or associated with the same SSB transmit beam that is transmitted at a certain SSB position. Thus, spectrum efficiency of the wireless network may be improved.

Aspects of the disclosure are initially described in the context of wireless communications systems. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to broadcast group identifier for multicast messages.

FIG. 1 illustrates an example of a wireless communications system 100 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

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

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

The base stations 105 may communicate with the core network 130, or with one another, or both. For example, the base stations 105 may interface with the core network 130 through one or more backhaul links 120 (e.g., via an S1, N2, N3, or other interface) . The base stations 105 may communicate with one another over the backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) , or indirectly (e.g., via core network 130) , or both. In some examples, the backhaul links 120 may be or include one or more wireless links.

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

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

The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

The UEs 115 and the base stations 105 may wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR) . Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.

In some examples (e.g., in a carrier aggregation configuration) , a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers. A carrier may be associated with a frequency channel (e.g., an evolved universal mobile telecommunication system terrestrial radio access (E-UTRA) absolute radio frequency channel number (EARFCN) ) and may be positioned according to a channel raster for discovery by the UEs 115. A carrier may be operated in a standalone mode where initial acquisition and connection may be conducted by the UEs 115 via the carrier, or the carrier may be operated in a non-standalone mode where a connection is anchored using a different carrier (e.g., of the same or a different radio access technology) .

The communication links 125 shown in the wireless communications system 100 may include uplink transmissions from a UE 115 to a base station 105, or downlink transmissions from a base station 105 to a UE 115. Carriers may carry downlink or uplink communications (e.g., in an FDD mode) or may be configured to carry downlink and uplink communications (e.g., in a TDD mode) .

Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) . In a system employing MCM techniques, a resource element may include one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) . Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams) , and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE 115.

The time intervals for the base stations 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T _s= 1/ (Δf _max·N _f) seconds, where Δf _max may represent the maximum supported subcarrier spacing, and N _f may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) . Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .

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

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

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

Each base station 105 may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station 105 (e.g., over a carrier) and may be associated with an identifier for distinguishing neighboring cells (e.g., a physical cell identifier (PCID) , a virtual cell identifier (VCID) , or others) . In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) over which the logical communication entity operates. Such cells may range from smaller areas (e.g., a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station 105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas 110, among other examples.

A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by the UEs 115 with service subscriptions with the network provider supporting the macro cell. A small cell may be associated with a lower-powered base station 105, as compared with a macro cell, and a small cell may operate in the same or different (e.g., licensed, unlicensed) frequency bands as macro cells. Small cells may provide unrestricted access to the UEs 115 with service subscriptions with the network provider or may provide restricted access to the UEs 115 having an association with the small cell (e.g., the UEs 115 in a closed subscriber group (CSG) , the UEs 115 associated with users in a home or office) . A base station 105 may support one or multiple cells and may also support communications over the one or more cells using one or multiple component carriers.

In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., MTC, narrowband IoT (NB-IoT) , enhanced mobile broadband (eMBB) ) that may provide access for different types of devices.

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

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

Some UEs 115 may be configured to employ operating modes that reduce power consumption, such as half-duplex communications (e.g., a mode that supports one-way communication via transmission or reception, but not transmission and reception simultaneously) . In some examples, half-duplex communications may be performed at a reduced peak rate. Other power conservation techniques for the UEs 115 include entering a power saving deep sleep mode when not engaging in active communications, operating over a limited bandwidth (e.g., according to narrowband communications) , or a combination of these techniques. For example, some UEs 115 may be configured for operation using a narrowband protocol type that is associated with a defined portion or range (e.g., set of subcarriers or resource blocks (RBs) ) within a carrier, within a guard-band of a carrier, or outside of a carrier.

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

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

In some systems, the D2D communication link 135 may be an example of a communication channel, such as a sidelink communication channel, between vehicles (e.g., UEs 115) . In some examples, vehicles may communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these. A vehicle may signal information related to traffic conditions, signal scheduling, weather, safety, emergencies, or any other information relevant to a V2X system. In some examples, vehicles in a V2X system may communicate with roadside infrastructure, such as roadside units, or with the network via one or more network nodes (e.g., base stations 105) using vehicle-to-network (V2N) communications, or with both.

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services 150. The operators IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.

Some of the network devices, such as a base station 105, may include subcomponents such as an access network entity 140, which may be an example of an access node controller (ANC) . Each access network entity 140 may communicate with the UEs 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs) . Each access network transmission entity 145 may include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105) .

The wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) . Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

The wireless communications system 100 may also operate in a super high frequency (SHF) region using frequency bands from 3 GHz to 30 GHz, also known as the centimeter band, or in an extremely high frequency (EHF) region of the spectrum (e.g., from 30 GHz to 300 GHz) , also known as the millimeter band. In some examples, the wireless communications system 100 may support millimeter wave (mmW) communications between the UEs 115 and the base stations 105, and EHF antennas of the respective devices may be smaller and more closely spaced than UHF antennas. In some examples, this may facilitate use of antenna arrays within a device. The propagation of EHF transmissions, however, may be subject to even greater atmospheric attenuation and shorter range than SHF or UHF transmissions. The techniques disclosed herein may be employed across transmissions that use one or more different frequency regions, and designated use of bands across these frequency regions may differ by country or regulating body.

The wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

A base station 105 or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.

The base stations 105 or the UEs 115 may use MIMO communications to exploit multipath signal propagation and increase the spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such techniques may be referred to as spatial multiplexing. The multiple signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the multiple signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords) . Different spatial layers may be associated with different antenna ports used for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO) , where multiple spatial layers are transmitted to the same receiving device, and multiple-user MIMO (MU-MIMO) , where multiple spatial layers are transmitted to multiple devices.

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

A base station 105 or a UE 115 may use beam sweeping techniques as part of beam forming operations. For example, a base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions. For example, the base station 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the base station 105.

Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions and may report to the base station 105 an indication of the signal that the UE 115 received with a highest signal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station 105 to a UE 115) . The UE 115 may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS) , a channel state information reference signal (CSI-RS) ) , which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook) . Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal) . The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR) , or otherwise acceptable signal quality based on listening according to multiple beam directions) .

UE 115 may use the techniques described herein to determine if a multicast message, transmitted from base station 105, is intended for UE 115 based on information associated with an SSB index selected based on a cell synchronization procedure (e.g., for coverage area 110) . More specifically, base station 105 may assign a group identifier (e.g., a group common radio network temporary identifier (RNTI) ) to a group of UEs 115 that are associated with a common SSB position via one broadcast communication. In some examples, UE 115 may determine that a multicast message is intended for UE 115 based on an association between the SSB position of UE 115 and the group identifier used in the encoding of control information corresponding to the multicast message. For example, UE 115 may determine the multicast message is directed to UE 115 based on downlink control information associated with the multicast message being encoded with a group identifier corresponding to the SSB index selected by UE 115.

In other examples, base station 105 may indicate a single group common RNTI for all SSB positions, and UE 115 may determine a multicast message is intended for UE 115 when an SSB index identifier associated with the SSB position of UE 115 is present in control information corresponding to the multicast message. For example, UE 115 may determine the multicast message is directed to UE 115 based on downlink control information associated with the multicast message being encoded with the group identifier and containing an SSB index identifier corresponding to the SSB index selected by UE 115.

FIG. 2 illustrates an example of wireless communications system 200 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. In some examples, wireless communications system 200 may implement aspects of wireless communications system 100. Wireless communications system 200 may include base station 105-a and UEs 115-a, 115-b, and 115-c, which may be examples of corresponding base stations 105 and UEs 115, respectively, as described above with reference to FIG. 1.

Base station 105-a may support multicast to a 5G cell (e.g., in a standalone or non-standalone mode) that UEs 115-a, 115-b, and 115-c may search for and synchronize with to acquire time and frequency synchronization with the cell and decode the Cell ID of that cell such that the UEs 115-a, 115-b, and 115-c may receive network communications from base station 105-a. UEs 115-a, 115-b, and 115-c attempting to synchronize with the 5G cell of base station 105-a may use broadcast synchronization signals (SSs) from base station 105-a to determine preferred beams for future communications between UEs 115-a, 115-b, and 115-c and base station 105-a. In some cases, once UEs 115-a, 115-b, and 115-c are synchronized with the cell and select an optimal beam, UEs 115-a, 115-b, and 115-c may perform a number of establishment communications with base station 105-a before UEs 115-a, 115-b, and 115-c are capable of receiving multicast communications from base station 105-a. Although UEs 115-a, 115-b, and 115-c will eventually be capable of receiving multicast communications from base station 105-a, the multicast preparation may be inefficient due to the large signaling overhead between base station 105-a and each of UEs 115-a, 115-b, and 115-c to be addressed with a multicast communication.

The described techniques provide for an efficient way for base station 105-a to send identical information to a group of UEs (e.g., UEs 115-a and 115-b) that are associated with a common SSB position. A 5G cell search and synchronization procedure may include UEs 115-a, 115-b, and 115-c tuning to a specific frequency to attempt to decode a PSS and an SSS. If UEs 115-a, 115-b, and 115-c successfully detect the PSS and SSS, then UEs 115-a, 115-b, and 115-c may attempt to decode the PBCH to determine, for example, system frame number (SFN) , SSB index, raster offset, default downlink numerology, remaining minimum system information (RMSI) configuration, demodulation reference signal (DMRS) location, or some combination thereof. If UEs 115-a, 115-b, and 115-c successfully decode the PBCH, then UEs 115-a, 115-b, and 115-c may be capable of receiving control information and data from base station 105-a associated with the 5G cell.

The PSS, SSS, and PBCH may form an SSB such as a four symbol SSB. For example, an SSB may include PSS and SSS that each occupy one symbol and 127 subcarriers as well as PBCH that spans across three symbols and 240 subcarriers. A plurality of SSBs may be transmitted, from base station 105-a, in a group forming an SS Burst (one SSB per beam) that is used during beam sweeping by changing beam direction (e.g., beams 240, 245, 250, and 255) for each SSB transmission (e.g.,

SSB transmissions

220, 225, 230, and 235) . In some examples, base station 105-a may define multiple candidate positions for SSBs within a radio frame, and this number may correspond to the number of beams radiated in a certain direction (e.g., four SSB positions corresponding to

SSB transmissions

220, 225, 230, and 235) . Each SSB position may be identified by a unique number, which may be referred to herein as an SSB index, and the identification of which SSB is detected by a UE depends on where the UE is located. SSBs with the same content may be transmitted repeatedly at a number of positions (e.g., four repetitions corresponding to SSB transmissions 220-a, 220-b, 220-c, and 220-d) . A beam sweeping mechanism may be used by UEs 115-a, 115-b, and 115-c to measure one or more SSB positions within an SSB period 215 and identify the best beam for communications between each of UEs 115-a, 115-b, and 115-c and base station 105-a and the associated SSB index.

In some examples, the PBCH contains a master information block (MIB) , and the MIB is transmitted with a periodicity (e.g., 80 ms) , in which SSBs with the same MIB content are transmitted repeatedly at a number of positions (e.g., four repetitions corresponding to SSB transmissions 225-a, 225-b, 225-c, and 225-d) . This periodicity may be referred to as a MIB period 210. The whole MIB period 210 may be further divided into a number of SSB periods 215. SSB period may span in time from a first repetition of an SSB transmission 220-a to the subsequent repetition of the same SSB transmission 220-b. In some cases, the SSB period 215 length may be up to 80 milliseconds (e.g., 5, 10, 20, 40, or 80 ms) . Within SSB period 215, the number of SSB positions (e.g., three or four positions) , and the first symbol of each position, shown by different shadings, are dependent on the subcarrier space (SCS) and carrier frequency. In some examples, the possible number of SSB positions may range from about 4 to 64 positions.

Base station 105-a may be equipped with multiple antennas, and each SSB position (e.g., each of the four SSB positions shown corresponding to SSB transmissions 220-a, 225-a, 230-a, and 235-a) within SSB period 215 may be transmitted with a certain transmit beam (e.g., beams 240, 245, 250, and 255) to extend the coverage. Different beams (e.g., beams 240, 245, 250, and 255) may be used at multiple SSB positions to cover a large area, for example, to seamlessly cover the whole cell of base station 105-a. For each SSB position within an SSB period 215, each of UEs 115-a, 115-b, and 115-c may combine their multiple received samples (e.g., SSB transmissions 225-a, 225-b, 225-c, and 225-d) in the same position (e.g., the second position) of multiple SSB periods because these received samples are sent with the same transmit beam (e.g., beam 245) . In some cases, the SSB transmit beam directions (e.g., beams 240, 245, 250, and 255) of all SSB beam positions (e.g., the four shaded blocks) within one SSB period 215 may be referred to as an SSB transmit beam pattern.

As shown, SSB period 215 has 4 positions, in each of which SSB may be sent with a different beam (e.g., beams 240, 245, 250, and 255) . UE 115-a and UE 115-b form a UE group located in the beam coverage of SSB position 4 corresponding to beam 255, and UE 115-c may be located in the beam coverage of SSB position 2 corresponding to beam 245. Thus, UEs 115-a, 115-b, and 115-c may receive the SSB at the respective time of these two positions. During data transfer, base station 105-a may notify the index of SSB positions to UEs 115-a, 115-b, and 115-c, so as to indicate a respective transmit beam. Then, UEs 115-a, 115-b, and 115-c may use the corresponding receive beam to receive data from base station 105-a. Each SSB position may be linked with at least one physical random access channel (PRACH) resource.

When each of UEs 115-a, 115-b, and 115-c selects an SSB position, each of UEs 115-a, 115-b, and 115-c may send a random access (RA) preamble at the linked PRACH resource. Then, base station 105-a may know what SSB position is selected by each of the UEs 115-a, 115-b, and 115-c. UEs 115-a and 115-b may form UE group 205-a as they share a similar physical location and beam 255. UE 115-c may be a part of another UE group 205-b, corresponding to beam 245, in a different physical location than UEs 115-a and 115-b.

Conventionally, when base station 105-a had identical data and/or signaling to sent to each of the UEs 115-a, 115-b, and 115-c individually, base station 105-a may initially send a dedicated message to each of the UEs 115-a, 115-b, and 115-c to assign a multicast-RNTI (called as G-RNTI) , and then the base station 105-a may perform multicast data transfer by addressing at this multicast-RNTI in a physical downlink control channel (PDCCH) . This method results in a large signaling overhead for each dedicated assignment message to each UE 115.

However, UEs 115-a, 115-b, and 115-c may each use the techniques described herein to determine if a multicast message pertains to the UE 115, with reduced signaling overhead compared to conventional methods, based on information associated with the SSB index selected by UEs 115-a, 115-b, and 115-c during cell synchronization. More specifically, base station 105-a may assign a group identifier (e.g., a group common radio network temporary identifier (RNTI) ) to UE groups 205-a and 205-b that are associated with the common SSB position via broadcast communications. In some examples, UEs 115-a, 115-b, and 115-c may determine a multicast message is intended for UE 115 based on an association between the common SSB position of the UE 115 and the group identifier used to encode the control information corresponding to the multicast message. In other examples, base station 105-a may use a single common RNTI for all SSB positions, and UEs 115-a, 115-b, and 115-c may determine a multicast message is intended for UE 115 when an SSB index identifier associated with the SSB position of UE 115 is present in control information corresponding to the multicast message.

FIG. 3 illustrates an example of a synchronization signal block association map 300 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. In some examples, synchronization signal block association map 300 may implement aspects of

wireless communications systems

100 and 200.

In some cases, a UE 115 may determine if a multicast message, from a base station 105, pertains to the UE 115 based on information associated with the SSB index selected by the UE 115. Specifically, a network may map group identifiers (e.g., RNTI values) to SSB indices corresponding to SSB positions. For example, a base station 105 may assign a group identifier (e.g., a group common RNTI) to a UE group associated with a common SSB position via broadcast communications. For instance, a base station 105 may broadcast to all UEs 115 a list of group-common RNTI values for a number of the SSB positions, where one RNTI value may be associated with at least one SSB index. Since this message is broadcast to all UEs 115 (e.g., by system information) , this process may save signaling overhead associated with assigning group-common RNTI to each UE individually. In some examples, the broadcast message may be a system information block (SIB) or a radio resource configuration (RRC) message.

In some examples, a UEs 115 may determine a multicast message is intended for UE 115 based on an association between the SSB position of the UE and the group identifier used in encoding of control information corresponding to the multicast message. A base station may send identical (e.g., multicast) data or signaling to a group of UEs by associating the identical information with one of the previously indicated RNTI 320 values in a PDCCH 315, where the UE group is covered by the SSB transmit beam that may be sent at the SSB position corresponding to this RNTI. A UE 115 may monitor PDCCH 315 to detect the transmission of a multicast message (e.g., data and/or control signaling) associated with the RNTI value 320 corresponding to its selected SSB index 310 corresponding to the received SSB position. If UE 115 decodes the PDCCH 315 successfully with the RNTI 320 associated with the SSB index 310, then UE 115 may decode the message received in the associated physical downlink shared channel (PDSCH) indicated by the PDCCH 315. In some examples, the PDCCH 315 may have a cyclic redundancy check (CRC) scrambled by RNTI 320.

An example mapping between RNTI values 320, SSB indices 310, and UE groups 305 is shown in FIG. 3. For instance, RNTI 1 320-a may be associated with SSB Index 1 310-a via association 325-a, and SSB Index 1 310-a may be further associated with UE group 1 305-a via association 330-a. In some cases, association 325 may be indicated by the broadcast message from the base station 105 to all UEs 115, and association 330 may be known by each UE 115 because each UE 115 knows at which SSB position, and thus SSB index, it selected to receive an SSB transmit beam. In another example, RNTI 2 320-b may be associated with SSB Index 2 310-b and SSB Index 3 310-c via association 325-b and 325-c, respectively. Also, SSB Index 2 310-b may be further associated with UE group 2 305-b via association 330-b, and SSB Index 3 310-c may be further associated with UE group 3 305-c via association 330-b. In this case, a multicast message may be sent to UE group 2 305-b and UE group 3 305-c together.

Therefore, a RNTI 320 may map to one or more SSB indices 310, and an SSB index 310 may map to one or more UE groups 305. There may be up to N RNTIs 320, SSB indices 310, and UE groups 305, which may be based on the SSB configuration (e.g., SSB transmit beam pattern) .

In some cases, a base station 105 may use multicast messages to send signaling that indicates the change of the SSB beam, such as beam power change or beam position change. Additionally or alternatively, the base station 105 may send data (e.g., location related information) to the group of UEs located in a region that is covered by a common SSB beam.

If a UE 115 selects a new SSB index associated with an SSB position to receive SSB (e.g., after scanning or re-scanning the SSB beam) , the UE 115 may receive subsequent multicast messages associated with the RNTI corresponding to the new SSB index based on the previously received RNTI list. Thus, avoiding the dedicated signaling indicated what RNTI to use for the current SSB index.

FIG. 4 illustrates an example of a synchronization signal block association map 400 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. In some examples, synchronization signal block association map 400 may implement aspects of

wireless communications systems

100 and 200.

In some cases, a UE 115 may determine if a multicast message, from a base station 105, pertains to the UE 115 based on information associated with the SSB index selected by the UE 115. Specifically, a base station may indicate (e.g., an explicitly signal in DCI) an SSB index identifier of SSB indices corresponding to SSB positions. For example, a base station 105 may assign a group identifier (e.g., a group common RNTI) to all UE groups associated with the SSB positions of the base station 105 as well as a set of SSB index identifiers via broadcast communications. For instance, a base station 105 may broadcast to all UEs 115 one group-common RNTI value and a number of SSB index identifiers. Since this message is broadcast to all UEs 115 (e.g., by system information) , this process may save signaling overhead associated with assigning a group-common RNTI and/or SSB index identifiers to each UE individually. In some examples, the broadcast message may be a SIB or an RRC message.

In some examples, a UEs 115 may determine a multicast message is intended for UE 115 based on an association between the SSB index identifier and the control information corresponding to the multicast message. For example, a base station 105 may send identical (e.g., multicast) data or signaling to a group of UEs by encoding the DCI 415 in the PDCCH with the indicated group common RNTI, and the base station 105 may indicate the SSB index identifier 420 in the DCI 415, where the UE group 405 may be covered by the SSB transmit beam that is sent at the SSB position, and related SSB index 410, corresponding to the SSB index identifier 420 included in the DCI 415.

A UE 115 may monitor PDCCH to detect the transmission of a multicast message (e.g., data and/or control signaling) associated with the RNTI value and the DCI 415 that contains an SSB index identifier 410, where the UE 115 receives the SSB transmit beam that is sent at the SSB position, and related SSB index 410, corresponding to the SSB index identifier 420. If UE 115 decodes the PDCCH successfully with the RNTI and the DCI 415 include an SSB index identifier 420 associated with the SSB index 410, then UE 115 may decode the message received in the associated PDSCH indicated by the PDCCH.

An example mapping between SSB index identifiers 420 in DCI 415, SSB indices 410, and UE groups 405 is shown in FIG. 4. For instance, SSB index identifier 1 420-a may be associated with SSB Index 1 410-a via association 425-a, and SSB Index 1 410-a may be further associated with UE group 1 405-a via association 430-a. In some cases, association 425 may be indicated by the broadcast message from the base station 105 to all UEs 115, and association 430 may be known by each UE 115 because each UE 115 knows at which SSB position, and thus the SSB index, it selected to receive an SSB transmit beam. In another example, SSB index identifier 2 420-b may be associated with SSB Index 2 410-b and SSB Index 3 410-c via association 425-b and 425-c, respectively. Also, SSB Index 2 410-b may be further associated with UE group 2 405-b via association 430-b, and SSB Index 3 410-c may be further associated with UE group 3 405-c via association 430-b. In this case, a multicast message may be sent to UE group 2 405-b and UE group 3 405-c together.

Therefore, an SSB index identifier 420 may map to one or more SSB indices 410, and an SSB index 410 may map to one or more UE groups 405. There may be up to N SSB index identifiers 420, SSB indices 410, and UE groups 405, which may be based on the SSB configuration (e.g., SSB transmit beam pattern) .

If a UE 115 selects a new SSB index associated with an SSB position to receive SSB (e.g., after scanning or re-scanning the SSB beam) , the UE 115 may receive subsequent multicast messages associated with the RNTI and the DCI 415 that contains the SSB index identifier 420 corresponding to the new SSB index. Thus, the method avoids the dedicated signaling indicated what RNTI or SSB index identifier to use for the current SSB index.

FIG. 5 illustrates an example of a process flow 500 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. In some examples, process flow 500 may implement aspects of

wireless communications system

100 and 200. Process flow 500 includes UE 115-d and base station 105-b, which may be examples of the corresponding devices as described with respect to FIGs. 1 through 4. For example, UE 115-d may be an example of UE 115-a of FIG. 2, and base station 105-b may be an example of base station 105-a of FIG. 2.

In the following description of the process flow 500, the operations between base station 105-b and UE 115-d may be transmitted in a different order than the exemplary order shown, or the operations performed by base station 105-b and UE 115-d may be performed in different orders or at different times. Certain operations may also be left out of the process flow 500, or other operations may be added to the process flow 500. It is to be understood that while base station 105-b and UE 115-d are shown performing a number of the operations of process flow 500, any wireless device may perform the operations shown.

At 505, base station 105-b may transmit, and UE 115-d may receive, a broadcast message that includes at least one group identifier.

At 510, base station 105-b may transmit an SS burst containing a plurality of SSB transmissions, and UE 115-d may monitor and receive one or more of the SSB transmissions. In some examples, each SSB transmission may correspond to an SSB index.

At 515, UE 115-d may identify, based on the monitoring at 510, a first SSB index for transmissions between base station 105-b and UE 115-d. For example, UE 115-d may select the first SSB index based on the SSB position associated with the first SSB index having an optimal signal quality.

At 520, UE 115-d may optionally transmit, to base station 105-b, an indication of the first SSB index selected at 515.

At 525, UE 115-d may optionally identify a first group identifier from the broadcast message at 505, where the first group identifier is associated with the first SSB index identified at 515 based on the broadcast message at 505.

At 530, base station 105-b may transmit, and UE 115-d may receive, a first multicast message associated with the at least one group identifier from the broadcast message at 505. The first multicast message may pertain to UE 115-d based on an association between the at least one group identifier and the first SSB index, where the first SSB index may be selected by UE 115-d at 515.

At 535, UE 115-d may determine that the first multicast message received at 530 pertains to UE 115-d based on an association between either the at least one group identifier and the first SSB index or between the first multicast message and the first SSB index.

At 540, UE 115-d may optionally identify, based on the monitoring of an SS burst, a second SSB index for transmissions between base station 105-b and UE 115-d.

At 545, UE 115-d may optionally transmit, to base station 105-b, an indication of the second SSB index selected at 540.

At 550, UE 115-d may optionally determine a second group identifier associated with the second SSB index based on the broadcast message at 505.

At 555, base station 105-b may optionally transmit, and UE 115-d may optionally receive, a second multicast message associated with the second group identifier.

At 560, UE 115-d may optionally determine that the second multicast message received at 530 pertains to UE 115-d based on an association between either the second group identifier and the second SSB index or between the second multicast message and the second SSB index.

FIG. 6 shows a block diagram 600 of a device 605 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a UE 115 as described herein. The device 605 may include a receiver 610, a communications manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to broadcast group identifier for multicast messages, etc. ) . Information may be passed on to other components of the device 605. The receiver 610 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The receiver 610 may utilize a single antenna or a set of antennas.

The communications manager 615 may receive, from a base station, at least one group identifier in a broadcast message, monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index, identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE, receive, from the base station, a multicast message associated with the at least one group identifier, and determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index. The communications manager 615 may be an example of aspects of the communications manager 910 described herein.

The actions performed by the UE communications manager 615 as described herein may be implemented to realize one or more potential advantages. One implementation may allow a UE 115 to save power and increase battery life by reducing the signaling overhead in receiving identical data and/or signaling with the same SSB transmit beam that is transmitted at a certain SSB position. Another implementation may provide improved quality and reliability of service at the UE 115, as spectrum efficiency of the wireless network may be improved.

The communications manager 615, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 615, or its sub-components may be executed by a general-purpose processor, a digital signal processor (DSP) , an application-specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 615, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 615, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 615, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 620 may transmit signals generated by other components of the device 605. In some examples, the transmitter 620 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The transmitter 620 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a device 705 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of a device 605, or a UE 115 as described herein. The device 705 may include a receiver 710, a communications manager 715, and a transmitter 745. The device 705 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to broadcast group identifier for multicast messages, etc. ) . Information may be passed on to other components of the device 705. The receiver 710 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The receiver 710 may utilize a single antenna or a set of antennas.

The communications manager 715 may be an example of aspects of the communications manager 615 as described herein. The communications manager 715 may include a broadcast component 720, a SSB monitor 725, a SSB index identifier 730, a multicast component 735, and an association identifier 740. The communications manager 715 may be an example of aspects of the communications manager 910 described herein.

The broadcast component 720 may receive, from a base station, at least one group identifier in a broadcast message.

The SSB monitor 725 may monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index.

The SSB index identifier 730 may identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE.

The multicast component 735 may receive, from the base station, a multicast message associated with the at least one group identifier.

The association identifier 740 may determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

The transmitter 745 may transmit signals generated by other components of the device 705. In some examples, the transmitter 745 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 745 may be an example of aspects of the transceiver 920 described with reference to FIG. 9. The transmitter 745 may utilize a single antenna or a set of antennas.

FIG. 8 shows a block diagram 800 of a communications manager 805 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The communications manager 805 may be an example of aspects of a communications manager 615, a communications manager 715, or a communications manager 910 described herein. The communications manager 805 may include a broadcast component 810, a SSB monitor 815, a SSB index identifier 820, a multicast component 825, an association identifier 830, a group identifier manager 835, an index association identifier 840, a decoder 845, a SSB index ID manager 850, a DCI component 855, and a DCI association identifier 860. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The broadcast component 810 may receive, from a base station, at least one group identifier in a broadcast message. In some cases, the broadcast message includes system information and is received via a system information block or radio resource configuration signaling.

The SSB monitor 815 may monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index.

The SSB index identifier 820 may identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE. In some examples, the SSB index identifier 820 may identify, based on the monitoring, a second synchronization signal block index for transmissions between the base station and the UE. In some examples, the SSB index identifier 820 may transmit, to the base station, an indication of the first synchronization signal block index.

The multicast component 825 may receive, from the base station, a multicast message associated with the at least one group identifier. In some examples, the multicast component 825 may receive, from the base station, a second multicast message associated with the second group identifier. In some examples, the multicast component 825 may receive multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index. In some examples, the multicast component 825 may receive multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.

The association identifier 830 may determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

The group identifier manager 835 may receive a set of group identifiers in the broadcast message, where each group identifier of the set of group identifiers is associated with at least one synchronization signal block index. In some examples, the group identifier manager 835 may receive one group identifier in the broadcast message, where the one group identifier is associated with a set of synchronization signal block indices. In some examples, the group identifier manager 835 may determine a second group identifier associated with the second synchronization signal block index based on the broadcast message. In some cases, the at least one group identifier includes a common radio network temporary identifier.

The index association identifier 840 may identify a first group identifier from the broadcast message, the first group identifier being associated with the first synchronization signal block index. In some examples, the index association identifier 840 may identify a first group identifier from the broadcast message, the first group identifier being associated with a set of synchronization signal block indices that includes the synchronization signal block index. In some examples, the index association identifier 840 may identify a first synchronization signal block index identifier from the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index.

The decoder 845 may determine that the multicast message pertains to the UE is based on downlink control information associated with the multicast message being encoded with the first group identifier. In some examples, the decoder 845 may determine that the second multicast message pertains to the UE based on second downlink control information associated with the second multicast message being encoded with the second group identifier.

The SSB index ID manager 850 may receive a set of synchronization signal block index identifiers in the broadcast message, where each synchronization signal block index identifier of the set of synchronization signal block index identifiers is associated with at least one synchronization signal block index. In some examples, the SSB index ID manager 850 may identify a second synchronization signal block index identifier from the broadcast message, the second synchronization signal block index identifier being associated with the second synchronization signal block index.

The DCI component 855 may receive downlink control information associated with the multicast message. In some examples, the DCI component 855 may receive, from the base station, a second multicast message associated with second downlink control information, the second downlink control information being associated with the first group identifier.

The DCI association identifier 860 may determine that the multicast message pertains to the UE based on the downlink control information including the first synchronization signal block index identifier. In some examples, the DCI association identifier 860 may determine that the second multicast message pertains to the UE based on the second downlink control information including the second synchronization signal block index identifier.

FIG. 9 shows a diagram of a system 900 including a device 905 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The device 905 may be an example of or include the components of device 605, device 705, or a UE 115 as described herein. The device 905 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 910, an I/O controller 915, a transceiver 920, an antenna 925, memory 930, and a processor 940. These components may be in electronic communication via one or more buses (e.g., bus 945) .

The communications manager 910 may receive, from a base station, at least one group identifier in a broadcast message, monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index, identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE, receive, from the base station, a multicast message associated with the at least one group identifier, and determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

The I/O controller 915 may manage input and output signals for the device 905. The I/O controller 915 may also manage peripherals not integrated into the device 905. In some cases, the I/O controller 915 may represent a physical connection or port to an external peripheral. In some cases, the I/O controller 915 may utilize an operating system such as

or another known operating system. In other cases, the I/O controller 915 may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, the I/O controller 915 may be implemented as part of a processor. In some cases, a user may interact with the device 905 via the I/O controller 915 or via hardware components controlled by the I/O controller 915.

The transceiver 920 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 920 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 920 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 925. However, in some cases the device may have more than one antenna 925, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 930 may include RAM and ROM. The memory 930 may store computer-readable, computer-executable code 935 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 930 may contain, among other things, a basic input output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 940 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 940 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 940. The processor 940 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 930) to cause the device 905 to perform various functions (e.g., functions or tasks supporting broadcast group identifier for multicast messages) .

Based on the use of a broadcast message to indicate the group identifier (s) and optional SSB index identifiers associated with SSB positions a processor of a UE 115 may efficiently determine if a multicast message pertains to the UE 115, with reduced signaling overhead compared to conventional methods. As such, when the multicast message is received, the processor may be ready to respond more efficiently through the reduction of a ramp up in processing power.

The code 935 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 935 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 935 may not be directly executable by the processor 940 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 10 shows a block diagram 1000 of a device 1005 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a base station 105 as described herein. The device 1005 may include a receiver 1010, a communications manager 1015, and a transmitter 1020. The device 1005 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to broadcast group identifier for multicast messages, etc. ) . Information may be passed on to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1010 may utilize a single antenna or a set of antennas.

The communications manager 1015 may transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier, transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index, and transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs. The communications manager 1015 may be an example of aspects of the communications manager 1310 described herein.

The actions performed by the communications manager 1015 as described herein may be implemented to realize one or more potential advantages. One implementation may allow a base station 105 to save power by reducing the signaling overhead in transmitting identical data and/or signaling with the same SSB transmit beam that is transmitted at a certain SSB position. Another implementation may provide improved quality and reliability of service at the base station 105, as spectrum efficiency of the wireless network may be improved.

The communications manager 1015, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communications manager 1015, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communications manager 1015, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communications manager 1015, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communications manager 1015, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1020 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1020 may utilize a single antenna or a set of antennas.

FIG. 11 shows a block diagram 1100 of a device 1105 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of a device 1005, or a base station 105 as described herein. The device 1105 may include a receiver 1110, a communications manager 1115, and a transmitter 1135. The device 1105 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to broadcast group identifier for multicast messages, etc. ) . Information may be passed on to other components of the device 1105. The receiver 1110 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1110 may utilize a single antenna or a set of antennas.

The communications manager 1115 may be an example of aspects of the communications manager 1015 as described herein. The communications manager 1115 may include a broadcast component 1120, a SSB manager 1125, and a multicast component 1130. The communications manager 1115 may be an example of aspects of the communications manager 1310 described herein.

The broadcast component 1120 may transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier.

The SSB manager 1125 may transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index.

The multicast component 1130 may transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs.

The transmitter 1135 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1135 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1135 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1135 may utilize a single antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a communications manager 1205 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The communications manager 1205 may be an example of aspects of a communications manager 1015, a communications manager 1115, or a communications manager 1310 described herein. The communications manager 1205 may include a broadcast component 1210, a SSB manager 1215, a multicast component 1220, a group identifier manager 1225, an index association identifier 1230, an encoder 1235, a SSB index ID manager 1240, a DCI component 1245, a DCI association identifier 1250, and a SSB index identifier 1255. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The broadcast component 1210 may transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier. In some cases, the broadcast message includes system information and is transmitted via a system information block or radio resource configuration signaling.

The SSB manager 1215 may transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index.

The multicast component 1220 may transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs.

In some examples, the multicast component 1220 may determine a first multicast message for the set of UEs associated with the first synchronization signal block index. In some examples, the multicast component 1220 may transmit the first multicast message and the first downlink control information, where the first multicast message pertains to the set of UEs based on the first downlink control information being encoded with the first group identifier.

In some examples, the multicast component 1220 may transmit, to the set of UEs, multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index. In some examples, the multicast component 1220 may transmit, to the set of UEs, multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.

The group identifier manager 1225 may transmit a set of group identifiers in the broadcast message, where each group identifier of the set of group identifiers is associated with at least one synchronization signal block index. In some examples, the group identifier manager 1225 may transmit one group identifier in the broadcast message, where the one group identifier is associated with a set of synchronization signal block indices. In some cases, the at least one group identifier includes a common radio network temporary identifier.

The index association identifier 1230 may determine a first group identifier included in the broadcast message, the first group identifier being associated with the first synchronization signal block index.

The encoder 1235 may encode first downlink control information associated with the first multicast message with the first group identifier.

The SSB index ID manager 1240 may transmit a set of synchronization signal block index identifiers in the broadcast message, where each synchronization signal block index identifier of the set of synchronization signal block index identifiers is associated with at least one synchronization signal block index. In some examples, the SSB index ID manager 1240 may determine a first synchronization signal block index identifier included in the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index.

The DCI component 1245 may transmit first downlink control information associated with the first multicast message, where the first downlink control information includes the first synchronization signal block index identifier.

The DCI association identifier 1250 may transmit the first multicast message, where the first multicast message pertains to the set of UEs based on the first downlink control information including the first synchronization signal block index identifier.

The SSB index identifier 1255 may receive, from each of the set of UEs, an indication of the first synchronization signal block index.

FIG. 13 shows a diagram of a system 1300 including a device 1305 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The device 1305 may be an example of or include the components of device 1005, device 1105, or a base station 105 as described herein. The device 1305 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communications manager 1310, a network communications manager 1315, a transceiver 1320, an antenna 1325, memory 1330, a processor 1340, and an inter-station communications manager 1345. These components may be in electronic communication via one or more buses (e.g., bus 1350) .

The communications manager 1310 may transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier, transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index, and transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs.

The network communications manager 1315 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1315 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1320 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1320 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1320 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1325. However, in some cases the device may have more than one antenna 1325, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1330 may include RAM, ROM, or a combination thereof. The memory 1330 may store computer-readable code 1335 including instructions that, when executed by a processor (e.g., the processor 1340) cause the device to perform various functions described herein. In some cases, the memory 1330 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor 1340 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1340 may be configured to operate a memory array using a memory controller. In some cases, a memory controller may be integrated into processor 1340. The processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1330) to cause the device 1305 to perform various functions (e.g., functions or tasks supporting broadcast group identifier for multicast messages) .

Based on the use of a broadcast message to indicate the group identifier (s) and optional SSB index identifiers associated with SSB positions a processor of a base station 105 may efficiently reduce the signaling overhead in sending identical data and/or signaling to a group of UEs covered by or associated with the same SSB transmit beam that is transmitted at a certain SSB position. As such, the processor may be ready to respond more efficiently through the reduction of a ramp up in processing power.

The inter-station communications manager 1345 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1345 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1345 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

The code 1335 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1335 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1335 may not be directly executable by the processor 1340 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

FIG. 14 shows a flowchart illustrating a method 1400 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The operations of method 1400 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1400 may be performed by a communications manager as described with reference to FIGs. 6 through 9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1405, the UE may receive, from a base station, at least one group identifier in a broadcast message. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed by a broadcast component as described with reference to FIGs. 6 through 9.

At 1410, the UE may monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed by an SSB monitor as described with reference to FIGs. 6 through 9.

At 1415, the UE may identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed by an SSB index identifier as described with reference to FIGs. 6 through 9.

At 1420, the UE may receive, from the base station, a multicast message associated with the at least one group identifier. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed by a multicast component as described with reference to FIGs. 6 through 9.

At 1425, the UE may determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index. The operations of 1425 may be performed according to the methods described herein. In some examples, aspects of the operations of 1425 may be performed by an association identifier as described with reference to FIGs. 6 through 9.

FIG. 15 shows a flowchart illustrating a method 1500 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1500 may be performed by a communications manager as described with reference to FIGs. 6 through 9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1505, the UE may receive, from a base station, at least one group identifier in a broadcast message. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a broadcast component as described with reference to FIGs. 6 through 9.

At 1510, the UE may receive a set of group identifiers in the broadcast message, where each group identifier of the set of group identifiers is associated with at least one synchronization signal block index. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed by a group identifier manager as described with reference to FIGs. 6 through 9.

At 1515, the UE may monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed by an SSB monitor as described with reference to FIGs. 6 through 9.

At 1520, the UE may identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed by an SSB index identifier as described with reference to FIGs. 6 through 9.

At 1525, the UE may identify a first group identifier from the broadcast message, the first group identifier being associated with the first synchronization signal block index. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be performed by an index association identifier as described with reference to FIGs. 6 through 9.

At 1530, the UE may receive, from the base station, a multicast message associated with the at least one group identifier. The operations of 1530 may be performed according to the methods described herein. In some examples, aspects of the operations of 1530 may be performed by a multicast component as described with reference to FIGs. 6 through 9.

At 1535, the UE may determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index. The operations of 1535 may be performed according to the methods described herein. In some examples, aspects of the operations of 1535 may be performed by an association identifier as described with reference to FIGs. 6 through 9.

At 1540, the UE may determine that the multicast message pertains to the UE is based on downlink control information associated with the multicast message being encoded with the first group identifier. The operations of 1540 may be performed according to the methods described herein. In some examples, aspects of the operations of 1540 may be performed by a decoder as described with reference to FIGs. 6 through 9.

FIG. 16 shows a flowchart illustrating a method 1600 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1600 may be performed by a communications manager as described with reference to FIGs. 6 through 9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, a UE may perform aspects of the functions described below using special-purpose hardware.

At 1605, the UE may receive, from a base station, at least one group identifier in a broadcast message. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a broadcast component as described with reference to FIGs. 6 through 9.

At 1610, the UE may receive one group identifier in the broadcast message, where the one group identifier is associated with a set of synchronization signal block indices. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a group identifier manager as described with reference to FIGs. 6 through 9.

At 1615, the UE may receive a set of synchronization signal block index identifiers in the broadcast message, where each synchronization signal block index identifier of the set of synchronization signal block index identifiers is associated with at least one synchronization signal block index. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by an SSB index ID manager as described with reference to FIGs. 6 through 9.

At 1620, the UE may monitor a set of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by an SSB monitor as described with reference to FIGs. 6 through 9.

At 1625, the UE may identify, based on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed by an SSB index identifier as described with reference to FIGs. 6 through 9.

At 1630, the UE may identify a first group identifier from the broadcast message, the first group identifier being associated with a set of synchronization signal block indices that includes the synchronization signal block index. The operations of 1630 may be performed according to the methods described herein. In some examples, aspects of the operations of 1630 may be performed by an index association identifier as described with reference to FIGs. 6 through 9.

At 1635, the UE may identify a first synchronization signal block index identifier from the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index. The operations of 1635 may be performed according to the methods described herein. In some examples, aspects of the operations of 1635 may be performed by an index association identifier as described with reference to FIGs. 6 through 9.

At 1640, the UE may receive, from the base station, a multicast message associated with the at least one group identifier. The operations of 1640 may be performed according to the methods described herein. In some examples, aspects of the operations of 1640 may be performed by a multicast component as described with reference to FIGs. 6 through 9.

At 1645, the UE may receive downlink control information associated with the multicast message. The operations of 1645 may be performed according to the methods described herein. In some examples, aspects of the operations of 1645 may be performed by a DCI component as described with reference to FIGs. 6 through 9.

At 1650, the UE may determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index. The operations of 1650 may be performed according to the methods described herein. In some examples, aspects of the operations of 1650 may be performed by an association identifier as described with reference to FIGs. 6 through 9.

At 1655, the UE may determine that the multicast message pertains to the UE based on the downlink control information including the first synchronization signal block index identifier. The operations of 1655 may be performed according to the methods described herein. In some examples, aspects of the operations of 1655 may be performed by a DCI association identifier as described with reference to FIGs. 6 through 9.

FIG. 17 shows a flowchart illustrating a method 1700 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1700 may be performed by a communications manager as described with reference to FIGs. 10 through 13. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1705, the base station may transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a broadcast component as described with reference to FIGs. 10 through 13.

At 1710, the base station may transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed by an SSB manager as described with reference to FIGs. 10 through 13.

At 1715, the base station may transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed by a multicast component as described with reference to FIGs. 10 through 13.

FIG. 18 shows a flowchart illustrating a method 1800 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The operations of method 1800 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1800 may be performed by a communications manager as described with reference to FIGs. 10 through 13. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1805, the base station may transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed by a broadcast component as described with reference to FIGs. 10 through 13.

At 1810, the base station may transmit a set of group identifiers in the broadcast message, where each group identifier of the set of group identifiers is associated with at least one synchronization signal block index. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed by a group identifier manager as described with reference to FIGs. 10 through 13.

At 1815, the base station may transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed by an SSB manager as described with reference to FIGs. 10 through 13.

At 1820, the base station may determine a first multicast message for the set of UEs associated with the first synchronization signal block index. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed by a multicast component as described with reference to FIGs. 10 through 13.

At 1825, the base station may determine a first group identifier included in the broadcast message, the first group identifier being associated with the first synchronization signal block index. The operations of 1825 may be performed according to the methods described herein. In some examples, aspects of the operations of 1825 may be performed by an index association identifier as described with reference to FIGs. 10 through 13.

At 1830, the base station may encode first downlink control information associated with the first multicast message with the first group identifier. The operations of 1830 may be performed according to the methods described herein. In some examples, aspects of the operations of 1830 may be performed by an encoder as described with reference to FIGs. 10 through 13.

At 1835, the base station may transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs. The operations of 1835 may be performed according to the methods described herein. In some examples, aspects of the operations of 1835 may be performed by a multicast component as described with reference to FIGs. 10 through 13.

At 1840, the base station may transmit the first multicast message and the first downlink control information, where the first multicast message pertains to the set of UEs based on the first downlink control information being encoded with the first group identifier. The operations of 1840 may be performed according to the methods described herein. In some examples, aspects of the operations of 1840 may be performed by a multicast component as described with reference to FIGs. 10 through 13.

FIG. 19 shows a flowchart illustrating a method 1900 that supports a broadcast group identifier for multicast messages in accordance with aspects of the present disclosure. The operations of method 1900 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1900 may be performed by a communications manager as described with reference to FIGs. 10 through 13. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, a base station may perform aspects of the functions described below using special-purpose hardware.

At 1905, the base station may transmit, to a set of user equipments (UEs) , a broadcast message that includes at least one group identifier. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed by a broadcast component as described with reference to FIGs. 10 through 13.

At 1910, the base station may transmit one group identifier in the broadcast message, where the one group identifier is associated with a set of synchronization signal block indices. The operations of 1910 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed by a group identifier manager as described with reference to FIGs. 10 through 13.

At 1915, the base station may transmit a set of synchronization signal block index identifiers in the broadcast message, where each synchronization signal block index identifier of the set of synchronization signal block index identifiers is associated with at least one synchronization signal block index. The operations of 1915 may be performed according to the methods described herein. In some examples, aspects of the operations of 1915 may be performed by an SSB index ID manager as described with reference to FIGs. 10 through 13.

At 1920, the base station may transmit a set of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index. The operations of 1920 may be performed according to the methods described herein. In some examples, aspects of the operations of 1920 may be performed by an SSB manager as described with reference to FIGs. 10 through 13.

At 1925, the base station may determine a first multicast message for the set of UEs associated with the first synchronization signal block index. The operations of 1925 may be performed according to the methods described herein. In some examples, aspects of the operations of 1925 may be performed by a multicast component as described with reference to FIGs. 10 through 13.

At 1930, the base station may determine a first synchronization signal block index identifier included in the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index. The operations of 1930 may be performed according to the methods described herein. In some examples, aspects of the operations of 1930 may be performed by an SSB index ID manager as described with reference to FIGs. 10 through 13.

At 1935, the base station may transmit first downlink control information associated with the first multicast message, where the first downlink control information includes the first synchronization signal block index identifier. The operations of 1935 may be performed according to the methods described herein. In some examples, aspects of the operations of 1935 may be performed by a DCI component as described with reference to FIGs. 10 through 13.

At 1940, the base station may transmit a multicast message associated with the at least one group identifier to the set of UEs, where the multicast message pertains to the set of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, where the first synchronization signal block index is selected by the set of UEs. The operations of 1940 may be performed according to the methods described herein. In some examples, aspects of the operations of 1940 may be performed by a multicast component as described with reference to FIGs. 10 through 13.

At 1945, the base station may transmit the first multicast message, where the first multicast message pertains to the set of UEs based on the first downlink control information including the first synchronization signal block index identifier. The operations of 1945 may be performed according to the methods described herein. In some examples, aspects of the operations of 1945 may be performed by a DCI association identifier as described with reference to FIGs. 10 through 13.

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

Example 1: A method for wireless communication at a user equipment (UE) , comprising: receiving, from a base station, at least one group identifier in a broadcast message; monitoring a plurality of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index; identifying, based at least in part on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE; receiving, from the base station, a multicast message associated with the at least one group identifier; and determining that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.

Example 2: The method of example 1, wherein receiving the at least one group identifier in the broadcast message comprises: receiving a plurality of group identifiers in the broadcast message, wherein each group identifier of the plurality of group identifiers is associated with at least one synchronization signal block index.

Example 3: The method of example 1, wherein receiving the at least one group identifier in the broadcast message comprises: receiving one group identifier in the broadcast message, wherein the at least one group identifier is associated with a plurality of synchronization signal block indices.

Example 4: The method of any of examples 1 to 3, further comprising: identifying a first group identifier from the broadcast message, the first group identifier being associated with the first synchronization signal block index.

Example 5: The method of any of examples 1 to 4, wherein: determining that the multicast message pertains to the UE is based on downlink control information associated with the multicast message being encoded with the first group identifier.

Example 6: The method of any of examples 1 to 5, further comprising: identifying, based at least in part on the monitoring, a second synchronization signal block index for transmissions between the base station and the UE; determining a second group identifier associated with the second synchronization signal block index based at least in part on the broadcast message; receiving, from the base station, a second multicast message associated with the second group identifier; and determining that the second multicast message pertains to the UE based on second downlink control information associated with the second multicast message being encoded with the second group identifier.

Example 7: The method of any of examples 1 to 6, wherein receiving the at least one group identifier in the broadcast message further comprises: receiving a plurality of synchronization signal block index identifiers in the broadcast message, wherein each synchronization signal block index identifier of the plurality of synchronization signal block index identifiers is associated with at least one synchronization signal block index.

Example 8: The method of any of examples 1 to 7, further comprising: identifying a first group identifier from the broadcast message, the first group identifier being associated with a plurality of synchronization signal block indices that includes the synchronization signal block index.

Example 9: The method of any of examples 1 to 8, further comprising: identifying a first synchronization signal block index identifier from the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index.

Example 10: The method of any of examples 1 to 9, wherein receiving the multicast message comprises: receiving downlink control information associated with the multicast message; and determining that the multicast message pertains to the UE based on the downlink control information comprising the first synchronization signal block index identifier.

Example 11: The method of any of examples 1 to 10, further comprising: identifying, based at least in part on the monitoring, a second synchronization signal block index for transmissions between the base station and the UE; identifying a second synchronization signal block index identifier from the broadcast message, the second synchronization signal block index identifier being associated with the second synchronization signal block index; receiving, from the base station, a second multicast message associated with second downlink control information, the second downlink control information being associated with the first group identifier; and determining that the second multicast message pertains to the UE based on the second downlink control information comprising the second synchronization signal block index identifier.

Example 12: The method of any of examples 1 to 11, wherein receiving the multicast message associated with the at least one group identifier comprises: receiving multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index.

Example 13: The method of any of examples 1 to 12, wherein receiving the multicast message associated with the at least one group identifier comprises: receiving multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.

Example 14: The method of any of examples 1 to 13, further comprising: transmitting, to the base station, an indication of the first synchronization signal block index.

Example 15: The method of any of examples 1 to 14, wherein the broadcast message comprises system information and is received via a system information block or radio resource configuration signaling.

Example 16: The method of any of examples 1 to 15, wherein the at least one group identifier comprises a common radio network temporary identifier.

Example 17: An apparatus for wireless communications comprising a processor; memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of examples 1 to 16.

Example 18: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to perform a method of any of examples 1 to 16.

Example 19: An apparatus, comprising means for performing the method of any of examples 1 to 16.

Example 20: A method for wireless communication at a base station, comprising: transmitting, to a plurality of user equipments (UEs) , a broadcast message that includes at least one group identifier; transmitting a plurality of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index; and transmitting a multicast message associated with the at least one group identifier to the plurality of UEs, wherein the multicast message pertains to the plurality of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, wherein the first synchronization signal block index is selected by the plurality of UEs.

Example 21: The method of example 20: wherein transmitting the broadcast message that includes the at least one group identifier comprises: transmitting a plurality of group identifiers in the broadcast message, wherein each group identifier of the plurality of group identifiers is associated with at least one synchronization signal block index.

Example 21: The method of example 20: wherein transmitting the broadcast message that includes the at least one group identifier comprises: transmitting one group identifier in the broadcast message, wherein the at least one group identifier is associated with a plurality of synchronization signal block indices.

Example 22: The method of any of examples 20 to 21, further comprising: determining a first multicast message for the plurality of UEs associated with the first synchronization signal block index; determining a first group identifier included in the broadcast message, the first group identifier being associated with the first synchronization signal block index; encoding first downlink control information associated with the first multicast message with the first group identifier; and transmitting the first multicast message and the first downlink control information, wherein the first multicast message pertains to the plurality of UEs based on the first downlink control information being encoded with the first group identifier.

Example 23: The method of any of examples 20 to 22, wherein transmitting the broadcast message that includes the at least one group identifier comprises: transmitting a plurality of synchronization signal block index identifiers in the broadcast message, wherein each synchronization signal block index identifier of the plurality of synchronization signal block index identifiers is associated with at least one synchronization signal block index.

Example 24: The method of any of examples 20 to 23, further comprising: determining a first multicast message for the plurality of UEs associated with the first synchronization signal block index; determining a first synchronization signal block index identifier included in the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index; transmitting first downlink control information associated with the first multicast message, wherein the first downlink control information comprises the first synchronization signal block index identifier; and transmitting the first multicast message, wherein the first multicast message pertains to the plurality of UEs based on the first downlink control information comprising the first synchronization signal block index identifier.

Example 25: The method of any of examples 20 to 24, wherein transmitting the multicast message associated with the at least one group identifier comprises: transmitting, to the plurality of UEs, multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index.

Example 26: The method of any of examples 20 to 25, wherein transmitting the multicast message associated with the at least one group identifier comprises: transmitting, to the plurality of UEs, multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.

Example 27: The method of any of examples 20 to 26, further comprising: receiving, from each of the plurality of UEs, an indication of the first synchronization signal block index.

Example 28: The method of any of examples 20 to 27, wherein the broadcast message comprises system information and is transmitted via a system information block or radio resource configuration signaling.

Example 29: The method of any of examples 20 to 28, wherein the at least one group identifier comprises a common radio network temporary identifier.

Example 30: An apparatus for wireless communications comprising a processor; memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method of any of examples 20 to 29.

Example 31: A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to perform a method of any of examples 20 to 29.

Example 32: An apparatus, comprising means for performing the method of any of examples 20 to 29.

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

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

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

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special-purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive list such that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication at a user equipment (UE) , comprising:

receiving, from a base station, at least one group identifier in a broadcast message;

monitoring a plurality of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index;

identifying, based at least in part on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE;

receiving, from the base station, a multicast message associated with the at least one group identifier; and

determining that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.
The method of claim 1, wherein receiving the at least one group identifier in the broadcast message comprises:

receiving a plurality of group identifiers in the broadcast message, wherein each group identifier of the plurality of group identifiers is associated with at least one synchronization signal block index.
The method of claim 1, wherein receiving the at least one group identifier in the broadcast message comprises:

receiving one group identifier in the broadcast message, wherein the at least one group identifier is associated with a plurality of synchronization signal block indices.
The method of claim 1, further comprising:

identifying a first group identifier from the broadcast message, the first group identifier being associated with the first synchronization signal block index.
The method of claim 4, wherein:

determining that the multicast message pertains to the UE is based on downlink control information associated with the multicast message being encoded with the first group identifier.
The method of claim 5, further comprising:

identifying, based at least in part on the monitoring, a second synchronization signal block index for transmissions between the base station and the UE;

determining a second group identifier associated with the second synchronization signal block index based at least in part on the broadcast message;

receiving, from the base station, a second multicast message associated with the second group identifier; and

determining that the second multicast message pertains to the UE based on second downlink control information associated with the second multicast message being encoded with the second group identifier.
The method of claim 1, wherein receiving the at least one group identifier in the broadcast message further comprises:

receiving a plurality of synchronization signal block index identifiers in the broadcast message, wherein each synchronization signal block index identifier of the plurality of synchronization signal block index identifiers is associated with at least one synchronization signal block index.
The method of claim 1, further comprising:

identifying a first group identifier from the broadcast message, the first group identifier being associated with a plurality of synchronization signal block indices that includes the synchronization signal block index.
The method of claim 8, further comprising:

identifying a first synchronization signal block index identifier from the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index.
The method of claim 9, wherein receiving the multicast message comprises:

receiving downlink control information associated with the multicast message; and

determining that the multicast message pertains to the UE based on the downlink control information comprising the first synchronization signal block index identifier.
The method of claim 10, further comprising:

identifying, based at least in part on the monitoring, a second synchronization signal block index for transmissions between the base station and the UE;

identifying a second synchronization signal block index identifier from the broadcast message, the second synchronization signal block index identifier being associated with the second synchronization signal block index;

receiving, from the base station, a second multicast message associated with second downlink control information, the second downlink control information being associated with the first group identifier; and

determining that the second multicast message pertains to the UE based on the second downlink control information comprising the second synchronization signal block index identifier.
The method of claim 1, wherein receiving the multicast message associated with the at least one group identifier comprises:

receiving multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index.
The method of claim 1, wherein receiving the multicast message associated with the at least one group identifier comprises:

receiving multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.
The method of claim 1, further comprising:

transmitting, to the base station, an indication of the first synchronization signal block index.
The method of claim 1, wherein the broadcast message comprises system information and is received via a system information block or radio resource configuration signaling.
The method of claim 1, wherein the at least one group identifier comprises a common radio network temporary identifier.
A method for wireless communication at a base station, comprising:

transmitting, to a plurality of user equipments (UEs) , a broadcast message that includes at least one group identifier;

transmitting a plurality of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index; and

transmitting a multicast message associated with the at least one group identifier to the plurality of UEs, wherein the multicast message pertains to the plurality of UEs based on an association between either the at least one group identifier and a first synchronization signal block index or between the multicast message and the first synchronization signal block index, wherein the first synchronization signal block index is selected by the plurality of UEs.
The method of claim 17, wherein transmitting the broadcast message that includes the at least one group identifier comprises:

transmitting a plurality of group identifiers in the broadcast message, wherein each group identifier of the plurality of group identifiers is associated with at least one synchronization signal block index.
The method of claim 17, wherein transmitting the broadcast message that includes the at least one group identifier comprises:

transmitting one group identifier in the broadcast message, wherein the at least one group identifier is associated with a plurality of synchronization signal block indices.
The method of claim 17, further comprising:

determining a first multicast message for the plurality of UEs associated with the first synchronization signal block index;

determining a first group identifier included in the broadcast message, the first group identifier being associated with the first synchronization signal block index;

encoding first downlink control information associated with the first multicast message with the first group identifier; and

transmitting the first multicast message and the first downlink control information, wherein the first multicast message pertains to the plurality of UEs based on the first downlink control information being encoded with the first group identifier.
The method of claim 17, wherein transmitting the broadcast message that includes the at least one group identifier comprises:

transmitting a plurality of synchronization signal block index identifiers in the broadcast message, wherein each synchronization signal block index identifier of the plurality of synchronization signal block index identifiers is associated with at least one synchronization signal block index.
The method of claim 17, further comprising:

determining a first multicast message for the plurality of UEs associated with the first synchronization signal block index;

determining a first synchronization signal block index identifier included in the broadcast message, the first synchronization signal block index identifier being associated with the first synchronization signal block index;

transmitting first downlink control information associated with the first multicast message, wherein the first downlink control information comprises the first synchronization signal block index identifier; and

transmitting the first multicast message, wherein the first multicast message pertains to the plurality of UEs based on the first downlink control information comprising the first synchronization signal block index identifier.
The method of claim 17, wherein transmitting the multicast message associated with the at least one group identifier comprises:

transmitting, to the plurality of UEs, multicast signaling indicating a beam parameter of the synchronization signal block transmission associated with the first synchronization signal block index.
The method of claim 17, wherein transmitting the multicast message associated with the at least one group identifier comprises:

transmitting, to the plurality of UEs, multicast data associated with location information of a region covered by the synchronization signal block transmission associated with the first synchronization signal block index.
The method of claim 17, further comprising:

receiving, from each of the plurality of UEs, an indication of the first synchronization signal block index.
The method of claim 17, wherein the broadcast message comprises system information and is transmitted via a system information block or radio resource configuration signaling.
The method of claim 17, wherein the at least one group identifier comprises a common radio network temporary identifier.
An apparatus for wireless communication at a user equipment (UE) , comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

receive, from a base station, at least one group identifier in a broadcast message;

monitor a plurality of synchronization signal block transmissions from the base station, each synchronization signal block transmission corresponding to a synchronization signal block index;

identify, based at least in part on the monitoring, a first synchronization signal block index for transmissions between the base station and the UE;

receive, from the base station, a multicast message associated with the at least one group identifier; and

determine that the multicast message pertains to the UE based on an association between either the at least one group identifier and the first synchronization signal block index or between the multicast message and the first synchronization signal block index.
An apparatus for wireless communication at a base station, comprising:

a processor,

memory coupled with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

transmit, to a plurality of user equipments (UEs) , a broadcast message that includes at least one group identifier;

transmit a plurality of synchronization signal block transmissions, each synchronization signal block transmission corresponding to a synchronization signal block index; and

transmit a multicast message associated with the at least one group identifier to the plurality of UEs, wherein the multicast message pertains to the plurality of UEs based on an association between the at least one group identifier and a first synchronization signal block index, the first synchronization signal block index selected by the plurality of UEs.