Feedback for multicast transmissions when in inactive or idle mode

Abstract

Methods, systems, and apparatus for multicast wireless communications are described. A base station may configure a user equipment (UE) to provide feedback for a multicast transmission from the base station when the UE is in an inactive or idle mode. Based on a configuration sent from the base station to the UE, the UE may determine a resource or timing advance (TA) to be used to transmit a feedback message for the multicast communication. The base station may configure the UE with a plurality of TA commands, each TA command corresponding to a TA value and a set of channel metrics associated with a group of cells including a serving cell of the UE. Based on the channel metrics measured at the UE, the UE may determine a TA to be used for multicast feedback. The TA value may be determined using neural network modeling.

Description

[0001] Cross-references

[0002] This patent application claims priority to U.S. patent application No. 17 / 223,567, filed by ZHANG et al. on April 6, 2021, entitled “FEEDBACK FOR MULTICAST TRANSMISSIONS WHILE IN AN INACTIVE OR IDLE MODE,” which claims priority to U.S. provisional patent application No. 63 / 006,836, filed by ZHANG et al. on April 8, 2020, entitled “FEEDBACK FOR MULTICAST TRANSMISSIONS WHILE IN AN INACTIVE OR IDLE MODE,” all of which are assigned to the assignee of this application. Technical Field

[0003] The following relates generally to wireless communications, and more particularly to feedback for multicast transmissions.

[0004] Related technical description

[0005] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcasting, etc. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems), and fifth generation (5G) systems that may be referred to as new radio (NR) systems. These systems may use various technologies, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each base station or network access node simultaneously supporting the communication of multiple communication devices, which may be referred to as user equipment (UE) in addition.

[0006] In some wireless communication systems, after receiving a message from a base station, the UE may transmit feedback to the base station indicating whether the message was successfully received. For example, a base station may transmit a multicast message to one or more UEs (such as a UE group) served by the base station, and the UEs in the group may transmit feedback for the multicast message according to a timing advance (TA) associated with each of the UEs. However, a UE in an inactive or idle mode may not have a valid TA, and therefore may refrain from transmitting feedback, or may transition to a connected mode to obtain a valid TA before transmitting feedback. Refraining from transmitting feedback or transitioning to a connected mode may result in increased latency, waste of UE resources (such as power or battery life, etc.), or inefficient use of network resources, etc.

[0007] Overview

[0008] The systems, methods, and devices of the disclosure each have several innovative aspects, no single one of which is solely responsible for the desirable attributes disclosed herein.

[0009] One innovative aspect of the subject matter described in the present disclosure can be implemented in a method for wireless communication at a user equipment (UE). The method includes receiving from a base station one or more configurations for the UE to provide feedback associated with a multicast transmission from the base station when in an inactive mode or an idle mode, monitoring, by the UE, a set of time-frequency resources configured for the multicast transmission from the base station when in the inactive mode or the idle mode, and transmitting, by the UE, one or more multicast feedback messages according to the one or more configurations based on the monitoring when in the inactive mode or the idle mode.

[0010] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a wireless communication device. The wireless communication device includes a processor, a memory coupled to the processor, and instructions stored in the memory and executable by the processor to cause the apparatus to: receive from a base station one or more configurations for a UE to provide feedback associated with a multicast transmission from the base station when in an inactive mode or an idle mode, monitor, by the UE, a set of time-frequency resources configured for multicast transmission from the base station when in an inactive mode or an idle mode, and transmit, by the UE, one or more multicast feedback messages according to the one or more configurations based on the monitoring when in an inactive mode or an idle mode.

[0011] In some implementations, the methods and wireless communication devices may be configured to determine a set of random access channel resources available for multicast feedback based at least in part on a resource allocation indicated by the one or more configurations, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages via the set of random access channel resources.

[0012] In some implementations, these methods and wireless communication devices may be configured to determine a set of random access channel preambles available for multicast feedback based at least in part on the resource allocation indicated by the one or more configurations, and select a preamble from the set of random access channel preambles, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages via the selected preamble.

[0013] One innovative aspect of the subject matter described in the present disclosure can be implemented in a method for wireless communication at a base station. The method includes transmitting to a UE one or more configurations for multicast feedback by the UE when in an inactive mode or an idle mode, transmitting one or more multicast transmissions via a set of time-frequency resources configured for multicast communication, and monitoring one or more multicast feedback messages from the UE according to the one or more configurations based on transmitting the one or more multicast transmissions.

[0014] Another innovative aspect of the subject matter described in the present disclosure can be implemented in a wireless communication device. The wireless communication device includes a processor, a memory coupled to the processor, and instructions stored in the memory and executable by the processor to cause the apparatus to: transmit one or more configurations for multicast feedback by the UE in an inactive mode or an idle mode to a UE, transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communication, and monitor one or more multicast feedback messages from the UE according to the one or more configurations based on transmitting the one or more multicast transmissions.

[0015] In some implementations, the methods and wireless communication devices may be configured to transmit an indication of a set of random access channel resources available for multicast feedback in the one or more configurations, and monitor the set of random access channel resources for the one or more multicast feedback messages.

[0016] In some implementations, the methods and wireless communication devices may be configured to transmit an indication of a set of random access channel preambles available for multicast feedback in the one or more configurations, and to monitor for the one or more multicast feedback messages based on the set of random access channel preambles. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The details of one or more implementations of the subject matter described in the present disclosure are set forth in the accompanying drawings and the following description. However, the accompanying drawings illustrate only some typical aspects of the present disclosure and are therefore not to be considered as limiting its scope. Other features, aspects and advantages will become apparent from the description, drawings and claims.

[0019] Figure 1-4

[0013] A wireless communication system supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is illustrated.

[0020] Figure 5 and Figure 6 A process flow is shown for supporting feedback for multicast transmissions in accordance with aspects of the present disclosure.

[0021] Figure 7 and Figure 8 A block diagram of an apparatus supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown.

[0022] Fig. 9 A diagram of a communications manager supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown.

[0023] Fig.10

[0013] A system including a device supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown.

[0024] Fig.11 and Fig.12 A block diagram of an apparatus supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown.

[0025] Fig.13 A diagram of a communications manager supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown.

[0026] Fig.14 A diagram of a system including devices supporting feedback for multicast transmissions is shown in accordance with aspects of the present disclosure.

[0027] Figure 15-23 A flow chart illustrating a method of supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown.

[0028] Detailed Description

[0029] In some wireless communication systems, devices such as user equipment (UE) or base stations may support feedback messaging, such as hybrid automatic repeat request (HARQ) feedback messaging for multicast communication. The base station may configure resources for multicast feedback, and the UE may use the configured resources to transmit feedback messages (such as acknowledgement (ACK) feedback messages or negative ACK (NACK) feedback messages) to the base station. For example, the base station may transmit a multicast message to a group of UEs. The UEs in the group may fail to receive the multicast message, and based on the failure, the UE may transmit a NACK feedback message to the base station for retransmission of the multicast message. In order to reduce channel overhead, resources available for multicast feedback may be shared among multiple UEs (such as all UEs in the group), and these resources may be referred to as shared resources. Each of the multiple UEs in the group may use these resources (e.g., shared physical uplink control channel (PUCCH) resources) to transmit corresponding feedback messages for the multicast message to the base station.

[0030] A base station may configure a timing advance (TA) for a UE in an active mode, such as in a radio resource control (RRC) connected mode, and the UE may use the TA to transmit feedback for a multicast message. For example, the base station may configure the TA for the UE after the UE enters the active mode and establishes a connection with the base station, and the UE may use the TA to transmit a feedback message to the base station in response to a multicast message from the base station. In some aspects, the base station may transmit the multicast message to a group of UEs including the UE. UEs in the group that are in an inactive mode, such as an RRC active mode, or an idle mode, such as an RRC idle mode, may monitor for multicast messages, but because these UEs are in an inactive mode or an idle mode, these UEs may not have a valid or accurate TA to be used to transmit feedback messages in response to the multicast message. In order to transmit the feedback message, each UE in an inactive mode or an idle mode may enter a connected mode to establish a connection with the base station and obtain a TA, which may increase overhead or use power resources at the UE and increase latency associated with transmitting the feedback message and receiving any subsequent transmissions, such as retransmissions of the multicast message in the case of NACK feedback. In addition, some UEs in inactive or idle mode may refrain from transmitting feedback messages for the multicast message. In such an example, even if multiple UEs in inactive or idle mode fail to successfully decode the multicast message, the base station may not perform retransmission of the multicast message because the base station may not receive any feedback messages from the multiple UEs.

[0031] Various aspects generally relate to feedback, and more particularly to techniques for transmitting feedback for a multicast message by a UE in an inactive mode or an idle mode. Such techniques may include a base station transmitting a configuration to a UE to configure the UE to transmit feedback for a multicast message when the UE is in an inactive mode or an idle mode. The configuration may indicate resources (such as random access channel (RACH) resources or PUCCH resources) or RACH preambles for the UE, etc. The base station may transmit a multicast message to a UE in an inactive mode or an idle mode, and the UE may use the indicated resources to transmit feedback for the multicast message. For example, a UE operating in an inactive mode or an idle mode may determine a RACH preamble from a plurality of RACH preambles or a set of resources from a RACH resource, a PUCCH resource, or a resource pool available for feedback, and may transmit feedback using the determined resources using the determined RACH preamble.

[0032] Additionally or alternatively, the base station may transmit a TA command to the UE or group of UEs. The TA command may indicate a TA for use by the UE or group of UEs, and the TA may be based on a channel metric, a channel condition, or other factors associated with the UE or group of UEs. In some implementations, the base station may transmit multiple TA commands, and each TA command may indicate a TA corresponding to a serving cell for the UE or group of UEs or a corresponding set of channel metrics for one or more neighboring cells. The base station may determine the TA value using various techniques, such as neural network modeling (which may include the use of historical or current data), environmental conditions, or information from neighboring cell(s), etc.

[0033] The base station may transmit a plurality of multicast control channels (which may be associated with various multicast services) to the UE, and the UE may successfully decode a certain number of multicast control channels within a given duration (such as within a set of opportunities allocated for multicast communication). The UE may transmit a reception status report indicating the number of multicast control channels that were successfully decoded. In such an implementation, in order to determine the number of UEs that have successfully or unsuccessfully decoded the multicast control channel, the base station may determine the UEs (including active, idle, and inactive UEs) that monitor a given multicast service within a duration (which may be referred to herein as a counting duration). In order to limit the number of UEs that transmit reception status reports during the counting duration, the base station may configure some or all UEs served by the base station with a probability indicator corresponding to the probability that the UE transmits feedback for a multicast message during the counting duration.

[0034] Specific implementations of the subject matter described in the present disclosure may be implemented to achieve one or more of the following potential advantages. In some implementations, a base station may use the described techniques to configure a UE in an inactive or idle mode to transmit a feedback message for a multicast message. Such techniques may enable a base station to use feedback from an inactive UE or an idle UE to determine whether to retransmit a multicast message. Such techniques may also enable an inactive UE or an idle UE to transmit a feedback message for a multicast message without having a configured TA or having to enter a connected mode, which may reduce overhead and latency, improve UE performance, and increase battery life, among other things.

[0035] Various aspects generally relate to wireless communication systems, and more particularly to feedback for multicast transmissions. Various aspects of the present disclosure are described with respect to process flows. Various aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow diagrams related to feedback for multicast transmissions.

[0036] Figure 1 An example of a wireless communication system 100 supporting feedback for multicast transmissions according to various aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a long term evolution (LTE) network, an advanced LTE (LTE-A) network, an LTE-A Pro network, or a new radio (NR) network. In some examples, the wireless communication system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission-critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

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

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

[0039] Each base station 105 may communicate with the core network 130, or communicate with each other, or both. For example, the base station 105 may interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3 or other interfaces). The base stations 105 may communicate with each other directly (e.g., directly between the base stations 105), or indirectly (e.g., via the core network 130), or directly and indirectly on the backhaul link 120 (e.g., via X2, Xn or other interfaces). In some examples, the backhaul link 120 may be or include one or more wireless links.

[0040] One or more of the base stations 105 described herein may include or may be referred to by a person of ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a B node, an evolved B node (eNB), a next generation B node or a gigabit B node (any of which may be referred to as a gNB), a home B node, a home evolved B node, or other suitable terminology.

[0041] UE 115 may include or be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable term. A "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects such as electrical appliances or vehicles, meters, etc.

[0042] The UE 115 described herein may be able to communicate with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as base stations 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 as shown in .

[0043] The UE 115 and the base station 105 may communicate wirelessly with each other via one or more communication links 125 on one or more carriers. The term "carrier" may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier for the communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 may support communication with the UE 115 using carrier aggregation or multi-carrier operation. The UE 115 may be configured to have multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used in conjunction with both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0044] In some examples (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute Radio Frequency Channel Number (EARFCN)) and may be located according to a channel grid for discovery by UE 115. A carrier may operate in a standalone mode in which initial acquisition and connection may be made by UE 115 via the carrier, or a carrier may operate in a non-standalone mode in which a connection is anchored using a different carrier (e.g., a different carrier of the same or different radio access technology).

[0045] The communication link 125 shown in the wireless communication system 100 may include an uplink transmission from the UE 115 to the base station 105, or a downlink transmission from the base station 105 to the UE 115. A carrier may carry downlink or uplink communications (e.g., in an FDD mode), or may be configured to carry both downlink and uplink communications (e.g., in a TDD mode).

[0046] A carrier may be associated with a particular bandwidth of a radio frequency spectrum, and in some examples, the carrier bandwidth may be referred to as a "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of a determined number of bandwidths (e.g., 1.4, 3, 5, 10, 15, 20, 40, or 80 megahertz (MHz)) of a carrier of a particular radio access technology. A device (e.g., a base station 105, a UE 115, or both) of the wireless communication system 100 may have a hardware configuration that supports communications on a particular carrier bandwidth, or may be configurable to support communications on one of a set of carrier bandwidths. In some examples, the wireless communication system 100 may include a base station 105 or a UE 115 that supports simultaneous communications via carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate on a portion (e.g., a subband, a BWP) or all of a carrier bandwidth.

[0047] The signal waveform transmitted on the carrier may include multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system using MCM techniques, a resource element may include a symbol period (e.g., the duration of a modulation symbol) and a subcarrier, where the symbol period and the subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both). Thus, the more resource elements received by UE 115 and the higher the order of the modulation scheme, the higher the data rate of UE 115 can be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may further improve the data rate or data integrity of communications with UE 115.

[0048] One or more parameter sets for a carrier may be supported, where the parameter set may include a subcarrier spacing (Δf) and a cyclic prefix. A carrier may be divided into one or more BWPs with the same or different parameter designs. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time, and communications for a UE 115 may be limited to the one or more active BWPs.

[0049] The time interval of the base station 105 or the UE 115 can be expressed as a multiple of a basic time unit, and the basic time unit can be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the maximum supported subcarrier spacing, and Nf The maximum supported discrete Fourier transform (DFT) size may be indicated. Time intervals of communication resources may be organized according to radio frames, each having a specific 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).

[0050] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided into subframes (e.g., in the time domain), and each subframe may be further divided into a number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a number of code element periods (e.g., depending on the length of the cyclic prefix added before each code element period). In some wireless communication systems 100, a time slot may be further divided into a plurality of mini-time slots containing one or more code elements. Excluding the cyclic prefix, each code element period may contain one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating band.

[0051] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs)).

[0052] Physical channels may be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels may be multiplexed on a downlink carrier, for example, using one or more of a time division multiplexing (TDM) technique, a frequency division multiplexing (FDM) technique, or a hybrid TDM-FDM technique. A control region (e.g., a control resource set (CORESET)) for a physical control channel may be defined by a number of symbol periods and may extend across a system bandwidth or a subset of a system bandwidth of a carrier. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more of the UEs 115 may monitor or search a control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0053] Each base station 105 may provide communication coverage via one or more cells (e.g., macro cells, small cells, hot spots, or other types of cells, or any combination thereof). The term "cell" may refer to a logical communication entity used to communicate with a base station 105 (e.g., on a carrier), and may be associated with an identifier (e.g., a physical cell identifier (PCID), a virtual cell identifier (VCID), or other) used to distinguish adjacent cells. In some examples, a cell may also refer to a geographic coverage area 110 or a portion of a geographic coverage area 110 (e.g., a sector) on which a logical communication entity operates. The range of such a cell may range from a smaller area (e.g., a structure, a subset of a structure) to a larger area depending on various factors (such as the capabilities of the base station 105). For example, a cell may be or include a building, a subset of a building, or an external space between or overlapping a geographic coverage area 110, as well as other examples.

[0054] A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access to UEs 115 that have service subscriptions with a network provider that supports the macro cell. A small cell may be associated with a lower power base station 105 (compared to a macro cell), and the small cell may operate in the same or different (e.g., licensed, unlicensed) frequency band as the macro cell. A small cell may provide unrestricted access to UEs 115 that have service subscriptions with a network provider, or may provide restricted access to UEs 115 associated with the small cell (e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 associated with users in a home or office). A base station 105 may support one or more cells and may also support communications on one or more cells using one or more component carriers.

[0055] 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 to different types of devices.

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

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

[0058] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a base station 105 without human intervention. In some examples, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay such information to a central server or application that utilizes the information or presents the information to a person interacting with the application. Some UEs 115 may be designed to collect information or implement automated behavior of machines or other devices. Examples of applications for MTC devices include: smart metering, inventory monitoring, water level monitoring, equipment monitoring, health care monitoring, field survival monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

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

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

[0061] In some examples, UE 115 may also be able to communicate directly with other UE 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 communication may be within a geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of the base station 105, or may not be able to receive transmissions from the base station 105 for other reasons. In some examples, each group of UEs 115 communicating via D2D communication may utilize a one-to-many (1:M) system, wherein each UE 115 transmits to each other UE 115 in the group. In some examples, the base station 105 facilitates the scheduling of resources for D2D communication. In other cases, D2D communication is performed between each UE 115 without involving the base station 105.

[0062] In some systems, the D2D communication link 135 can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, the vehicles can communicate using vehicle-to-everything (V2X) communications, vehicle-to-vehicle (V2V) communications, or some combination of these communications. The vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some examples, vehicles in the V2X system can communicate with roadside infrastructure (such as roadside units), or with the network, or both via one or more network nodes (e.g., base station 105) using vehicle-to-network (V2N) communications.

[0063] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), and the EPC or 5GC may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility, and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to an external network. The control plane entity may manage non-access stratum (NAS) functions, such as mobility, authentication, and bearer management of UE 115 served by a base station 105 associated with the core network 130. User IP packets may be delivered via a user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to a network operator IP service 150. Operator IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0064] Some network devices (such as base stations 105) may include subcomponents, such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with each UE 115 through one or more other access network transport entities 145, which may be referred to as radio heads, smart radio heads, or transmission / reception points (TRPs). Each access network transport entity 145 may include one or more antenna panels. In some configurations, the various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or merged into a single network device (e.g., base station 105).

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

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

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

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

[0069] The base station 105 or UE 115 can use MIMO communication to utilize multipath signal propagation and improve spectral efficiency by transmitting or receiving multiple signals via different spatial layers. Such technology may be referred to as spatial multiplexing. For example, the transmitting device may transmit multiple signals via different antennas or different antenna combinations. Similarly, the receiving device may receive multiple signals via different antennas or different antenna combinations. Each of these multiple signals may be referred to as a separate spatial stream and may carry bits associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO technology includes single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device; and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

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

[0071] The base station 105 or the UE 115 may use beam sweeping techniques as part of a beamforming operation. For example, the base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with the UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by the base station 105 in different directions. For example, the base station 105 may transmit signals according to different sets of beamforming weights associated with different transmission directions. Transmissions in different beam directions may be used (e.g., by a transmitting device (such as the base station 105) or a receiving device (such as the UE 115)) to identify a beam direction used by the base station 105 for later transmission or reception.

[0072] Some signals, such as data signals associated with a particular recipient device, may be transmitted by base station 105 in a single beam direction, e.g., a direction associated with a recipient device, such as UE 115. In some examples, a beam direction associated with transmissions along a single beam direction may be determined based on signals transmitted in one or more beam directions. For example, UE 115 may receive one or more signals transmitted by base station 105 in different directions and may report to base station 105 an indication of the signal received by UE 115 with the highest signal quality or other acceptable signal quality.

[0073] In some examples, transmission 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 the base station 105 to the UE 115). The UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across the system bandwidth or one or more subbands. The base station 105 may transmit a reference signal that may be precoded or unprecoded (e.g., a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)). 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 by base station 105 in one or more directions, UE 115 may use similar techniques to transmit signals multiple times in different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115), or to transmit signals in a single direction (e.g., to transmit data to a receiving device).

[0074] A receiving device (e.g., UE 115) may try multiple reception configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a base station 105. For example, the receiving device may try multiple reception directions by receiving via different antenna subarrays, processing received signals according to different antenna subarrays, 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 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 reception configurations or reception directions. In some examples, the receiving device may use a single reception configuration to receive along a single beam direction (e.g., when receiving a data signal). The single reception configuration may be aligned on a beam direction determined based on listening according to different reception configuration directions (e.g., a beam direction determined to have the highest signal strength, the highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0075] The wireless communication system 100 may be a packet-based network that operates according to a layered protocol stack. In the user plane, the communication of the bearer or packet data convergence protocol (PDCP) layer may be IP-based. The radio link control (RLC) layer may perform packet segmentation and reassembly to communicate on a logical channel. The media access control (MAC) layer may perform priority handling and multiplex logical channels into transport channels. The MAC layer may also use error detection techniques, error correction techniques, or both to support retransmission of the MAC layer to improve link efficiency. In the control plane, the radio resource control (RRC) protocol layer may provide the establishment, configuration, and maintenance of an RRC connection that supports radio bearers of user plane data between UE 115 and base station 105 or core network 130. In the physical layer, transport channels may be mapped to physical channels.

[0076] UE 115 and base station 105 may support retransmission of data to increase the likelihood that the data is successfully received. HARQ feedback is a technique for increasing the likelihood of correctly receiving data on communication link 125. HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve the throughput of the MAC layer in poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, a device may support simultaneous slot HARQ feedback, wherein the device may provide HARQ feedback in a specific time slot for data received in a previous symbol in the time slot. In other cases, the device may provide HARQ feedback in a subsequent time slot or according to some other time interval.

[0077] The wireless communication system 100 may support multicast communications. The base station 105 may transmit a multicast message to a group of UEs 115, and these UEs 115 may monitor the time-frequency resources on which the multicast message is transmitted to attempt to decode the multicast message. The UE 115 may successfully or unsuccessfully decode the multicast message, and may then transmit feedback to the base station 105. The base station 105 may configure a TA for the UE 115, and a UE 115 in an active mode (such as in an RRC connected mode) may use the TA to transmit feedback. Once the UE 115 enters the active mode and establishes a connection with the base station 105, the base station 105 may configure a TA for the UE. In some cases, some UEs 115 may operate in an inactive or idle mode and may not have an active connection to the base station 105. These inactive or idle UEs 115 may not have a valid TA to be used to transmit messages (such as feedback). An inactive or idle UE 115 may transition to connected mode in order to acquire a TA before transmitting a message, which may introduce latency and increase the power consumed by the UE 115 .

[0078] In some aspects, a UE 115 in an inactive mode or idle mode may transmit feedback for multicast communications without transitioning to a connected state. For example, a UE 115 in an inactive or idle mode may determine resources, such as RACH resources or PUCCH resources, available for use by the UE 115 or a group of UEs 115 to transmit feedback when in an inactive or idle mode. The base station may transmit a configuration to the UEs 115 to convey or indicate to the UEs 115 the resources available for use in transmitting multicast feedback.

[0079] In some implementations, the base station 105 may transmit a TA command to the UEs 115 for use when in an inactive mode or an idle mode. In some other implementations, the base station 105 may transmit a set of TA commands to each UE 115. Each TA command may correspond to a corresponding TA value and a set of channel metrics for one or more cells, such as a serving cell of the UE 115 and one or more neighboring cells of the UE 115. The UE 115 may transmit a feedback message using a TA value corresponding to the TA command associated with the channel metric set of these cells to provide feedback for the multicast message. In some cases, the UE 115 may measure the channel metric at the UE 115, and may use a TA value corresponding to the measured channel metric. In some examples, the base station 105 or base stations 105 may perform neural network modeling on various parameters, and the UE 115 may use the modeling to determine possible TA values ​​for the TA command.

[0080] In some aspects, the UE 115 may successfully receive a number of physical control channels for multicast communications, such as a physical downlink control channel (PDCCH) or other type of physical layer control channel for multicast communications, and the base station 105 may request a status report indicating the number of physical control channels from the UEs 115. The base station 105 may provide a resource pool including time and frequency resources to the UE 115, and the UE 115 may use the resource pool to transmit the status report. In such a case, if the report indicates that the number of physical control channels for multicast communications that were successfully decoded is less than the number of physical control channels transmitted, the base station 105 may initiate a retransmission of one or more physical control channels for the multicast communication.

[0081] Figure 2 A wireless communication system 200 is shown that supports feedback for multicast transmissions according to aspects of the present disclosure. In some examples, the wireless communication system 200 can implement aspects of the wireless communication system 100. The wireless communication system 200 can include a UE 115 and a base station 105-a, which can be as described with reference to Figure 1 Corresponding examples of UE 115 and base station 105 are described.

[0082] One or more UEs 115 in the UE group 205 (e.g., UE 115-a and UE 115-c) may be in an active or connected mode (such as an RRC connected mode), wherein the UE 115 and the base station 105-a are in active communication and have an established RRC connection. Other UEs in the UE group 205 (e.g., UE 115-b) may be in an inactive mode (such as an RRC inactive mode), wherein the UE 115-b may maintain an RRC connection with the base station 105-a but is not active, and minimizes signaling and power consumption. In some other examples, some UEs 115 in the UE group 205 (such as UE 115-b) may be in an idle mode (such as an RRC idle mode), wherein the UE 115-b does not have an established RRC connection with the base station 105-a.

[0083] The wireless communication system 200 may support multicast communications between a base station 105-a and one or more UEs 115, such as UEs 115-a, UEs 115-b, and UEs 115-c within a UE group 205. For example, the base station 105-a may transmit one or more multicast communications 210 to the UE group 205. The base station 105-a may configure some of the UEs 115 in the UE group 205 to transmit feedback for the multicast communications to the base station 105-a. For example, the UE 115 may successfully decode the transmission and may transmit a corresponding ACK feedback message indicating the successful decoding, or the UE 115 may fail to successfully decode the transmission and may transmit a corresponding NACK feedback message indicating the decoding failure.

[0084] In some examples, UE 115-a may operate in a connected mode, and UE 115-a may have an effective TA that can be used for uplink communications between UE 115-a and base station 105-a. The TA may enable UE 115-a to adjust the timing of uplink transmissions (such as multicast feedback messages) to align with the timing of base station 105-a. Base station 105-a may expect uplink transmissions to arrive during an expected duration, and UE 115-a may adjust the timing of uplink transmissions so that the uplink transmissions arrive at base station 105-a during the expected duration. In some cases, other UEs 115 (such as UE 115-b) operating in an inactive mode or idle mode may not have an effective TA. In order to obtain an effective TA, UE 115-b may transition to a connected mode with base station 105-a, which takes time and utilizes limited UE resources (such as power), and there are other problems. Without a valid TA, UE 115-b may cause transmissions from UE 115-b to be misaligned with the expected timing at base station 105-a. This may cause base station 105-a to not detect uplink transmissions from UE 115-b due to an invalid TA (or lack of a TA). Base station 105-a may monitor a time window, and uplink transmissions from UE 115-a may arrive before or after the time window. Additionally or alternatively, uplink transmissions from UE 115-b may interfere with other uplink transmissions sent to base station 105-a (such as transmissions from other UEs 115).

[0085] As described above, aspects of the present disclosure enable a UE 115 (such as UE 115-b) in an idle mode or an inactive mode to transmit feedback for multicast communications while in the idle mode or inactive mode (i.e., without requiring the UE 115 to transition to a connected mode), which can reduce power consumption. Additionally or alternatively, the base station 105-a can support various multicast services, and enabling multicast feedback transmission while in the idle mode or inactive mode can enable the UE 115 (such as UE 115-b) to receive or otherwise participate in the various multicast services without having to switch to a connected mode.

[0086] To support multicast feedback from UEs 115 in an inactive or idle mode, base station 105-b may transmit a feedback configuration message 215 to UEs 115 (including UE 115-b), which UEs 115 may use to transmit feedback (such as feedback message 220) for multicast communications 210 when UEs 115 (including UE 115-b) are in an inactive or idle mode. The feedback configuration message 215 may include an indication of resources (including time resources, frequency resources, or spatial resources) for use by the one or more UEs 115 (including UE 115-b) to transmit multicast feedback. For example, the feedback configuration message 215 may indicate to UE 115-b the time and frequency resources that may be used by UE 115-b to transmit feedback message 220 based on whether UE 115-b successfully receives multicast communications 210. In some examples, base station 105 - a may transmit feedback configuration message 215 to UE 115 - b via a system information block (SIB) or a multicast control channel (MCCH), etc.

[0087] In some examples, the feedback configuration message 215 may indicate RACH resources or RACH preambles available for UE 115-b to transmit feedback message 220. For example, the base station 105-a may indicate one or more physical RACH (PRACH) preambles, and the UE 115-b may select one of these PRACH preambles and transmit the feedback message 220 using a waveform corresponding to the selected PRACH preamble. The availability of PRACH resources or PRACH preambles may enable UEs 115 (including UE 115-b) that do not have a valid TA to transmit feedback (which includes feedback message 220) for multicast communications. In some examples, the PRACH preamble may utilize a longer cyclic prefix or guard time to account for timing uncertainty and potential interference to other UEs 115 (e.g., UE 115-a and UE 115-c) in the system.

[0088] In some implementations, the base station 105-a may allocate a pool of PRACH resources or a pool of PRACH preambles to a UE 115 for use by a UE 115 in an inactive mode or an idle mode (such as a UE 115-b) to transmit a multicast feedback message, such as the feedback message 220. The UE 115-b may report a channel metric, such as a reference signal received power (RSRP) threshold, an angular direction (such as an altitude and azimuth value associated with one or more beams), a beam direction, a beam width, or a geographic location, and the base station 105-a may allocate a pool of PRACH resources or a pool of PRACH preambles based on these channel metrics. In various implementations, one or more UEs (including the UE 115-b) may use a service, and the base station 105-a may allocate a pool of PRACH resources or a pool of PRACH preambles based on the service. For example, the base station 105-a may allocate a first set of resources or preambles to a UE 115 using a first service, and may allocate a second set of resources or preambles to a UE 115 having a specified RSRP value. The UE 115-b may be able to determine (e.g., based on reported channel metrics or services used) a subset of PRACH resources or PRACH preambles in the feedback resource pool for transmitting the feedback message 220. In some other implementations, the base station 105-a may configure additional RACH opportunities for the UE 115-b to transmit the feedback message 220.

[0089] The base station 105-a may use information about the allocation of the resource pool to more efficiently transmit retransmissions to the UE 115. For example, if a set of resources or preambles are allocated for use by the UE 115-b when using a first beam that is different from the beam originally used to transmit the multicast communication 210, and the base station 105-a receives the feedback message 220 from the UE 115-b on the set of resources associated with the first beam, the base station 105-a may transmit the retransmission of the multicast message using the first beam instead of the beam originally used. As an additional example, if the base station 105-a receives a NACK in the feedback message 220 on resources corresponding to a relatively low RSRP value, the base station 105-a may transmit the retransmission with increased power to account for the low RSRP.

[0090] In some implementations, the base station 105-a may transmit an indication of PUCCH resources allocated for one or more UEs 115 (including UE 115-b) that may not have a valid TA (such as because they are operating in an inactive or idle mode) to transmit multicast feedback (such as feedback message 220). The base station 105-a may measure the energy level on the allocated PUCCH resources to determine whether the feedback message 220 is present. For example, the base station 105-a may receive a message on the designated PUCCH resources and may determine whether the message exceeds an energy threshold. If so, the base station 105-a may determine that the feedback message 220 has been transmitted on these resources. The UE 115-b may determine a PUCCH format for the feedback message 220, which may be a PUCCH format without user multiplexing (e.g., format 0, format 1, format 2, or format 3) to enable the base station 105-a to use energy detection. The UE 115-b may use other formats by allocating a code division multiplexing (CDM) resource (e.g., without invoking multiplexing). The base station 105-a may add one or more guard duration resource elements to the time domain, the frequency domain, or both to minimize interference of the feedback message 220 to other uplink transmissions. In some examples, the UE 115-b may determine the PUCCH format and may fill the payload of the feedback message 220 accordingly. For example, if the UE 115-b uses a PUCCH format other than format 0 or format 1 and has a single-bit payload to transmit, the UE 115-b may fill the feedback message 220 with one or more bits (such as up to three bits) to use PUCCH format 2, PUCCH format 3, or PUCCH format 4.

[0091] In some cases, UE 115-b may not transmit feedback message 220 to base station 105-a, and base station 105-a may not have information about the reason for the lack of feedback. In some examples, base station 105-a may configure UE 115 (including UE 115-b) to transmit a NACK message instead of an ACK message, and thus may refrain from transmitting a feedback message 220 including a NACK in response to successfully decoding a physical control channel for multicast communication and a corresponding multicast message of multicast communication 210. In some examples, UE 115-b may also refrain from transmitting a feedback message 220 including a NACK after failing to decode a control message. For example, if UE 115-b fails to successfully decode a control message, UE 115-b may not expect the corresponding multicast message scheduled by the control message. In this way, UE 115-b may not monitor for the multicast message and may not transmit NACK feedback. As a result, the base station 105 - a may be unaware that the UE 115 - b has failed to decode the multicast communication 210 , and accordingly, may determine not to perform a retransmission even though the UE 115 - b has not successfully decoded the multicast communication 210 .

[0092] The UE 115 may successfully decode the multicast communication and the base station 105-a may not receive NACK feedback, or the one or more UEs 115 may fail to successfully decode the multicast communication and the base station 105-a may not receive NACK feedback. In order to enable the base station 105-a to distinguish between these situations, the base station 105-a may provide a resource pool to the UE 115 (including UE 115-b), and the resource pool includes time and frequency resources that the UE 115 can use to transmit reception status reports. For example, the base station 105-a may allocate a resource pool to the UE 115-b, and the UE 115-b may use at least a subset of the resources in the resource pool to transmit a message to indicate the number of physical control channels used for the multicast communication successfully decoded by the UE 115-b. In some implementations, the resource pool may include or consist of one or both of a PRACH resource set or a PUCCH resource set. In addition, the base station 105-a may configure the UE 115-b to monitor one or more multicast opportunities, and may transmit to the base station 105-a an indication of the number of physical control channels for multicast communications that have been successfully decoded during the one or more opportunities. For example, the UE 115-b may receive from the base station 105-a a multicast grant that schedules several multicast opportunities for the UE 115-b, and the base station 105-a may choose to transmit a multicast message on these multicast opportunities. The UE 115-b may monitor these multicast opportunities, and may receive from the base station 105-a several physical control channels for multicast communications during one or more scheduled multicast opportunities. For example, the UE 115-b may receive one or more of these physical control channels, or in some cases, the UE 115-b may not receive any physical control channels. The UE 115-b may select resources from the allocated resource pool, and may then use these resources to transmit an indication of the number of transmissions that have been successfully decoded. Based on the indication, base station 105-a may compare the number of physical control channels transmitted to UE 115-b with the number of physical control channels that UE 115-b has indicated as being successfully decoded. If the report from UE 115-b indicates that the number of successfully decoded physical control channels is less than the number of those physical control channels transmitted by base station 105-a, base station 105-a may determine that the lack of NACK(s) from UE 115-b is due to UE 115-b failing to decode one or more of the physical control channels used for multicast communications, which may trigger base station 105-a to initiate a retransmission.

[0093] In some implementations, the base station 105-a may configure the UE 115-b with a given resource pool based on the number of physical control channels per reception status report. For example, the UE 115-b may decode the number of physical control channels, and the base station 105-a may select a first resource pool if a metric based on the number of physical control channels out of the total amount of physical control channels transmitted satisfies a threshold (e.g., if the ratio of the number of decoded physical control channels to the total amount of physical control channels transmitted is greater than a threshold). Similarly, the base station 105-a may select a second resource pool if the metric fails to meet the threshold (e.g., if the ratio of the number of decoded physical control channels to the total amount of physical control channels transmitted is less than a threshold). Each resource pool may correspond to different multicast resources (time or frequency resources), services, or channel types, etc.

[0094] Typically, the probability that the base station 105-a receives at least one NACK following a multicast communication increases (in some cases non-linearly) with the number of UEs 115 seeking to receive the multicast communication. As such, the base station 105-a may count or otherwise determine or estimate the number of UEs 115 that are currently in an inactive mode or idle mode (e.g., the number of inactive or idle UEs 115 in the UE group 205) that are receiving the multicast communication. By knowing the number of UEs 115 that are in an inactive or idle mode, the base station 105-a may better utilize any multicast feedback.

[0095] In some examples, the base station 105-a may perform multicast communications for different services (e.g., MBMS, enhanced MBMS, etc.). However, not all UEs 115 may have the ability to receive all services. For example, UE 115-b may support a service when in connected mode, but may not support the same service when in inactive or idle mode. In some aspects, the base station 105-a may broadcast a counting duration for each provided multicast service and an indication of a resource pool (e.g., including PUCCH or PRACH resources) on which a response is to be transmitted. The base station 105-a may then count the number of UEs 115 in inactive or idle mode that are receiving multicast communications for a given service via the broadcast. During each counting duration, a UE 115 in idle mode or inactive mode (such as UE 115-b) may use resources from the indicated resource pool to transmit a service request message indicating that UE 115-b is interested in receiving the service. The base station 105-a may count, determine, or estimate the number of UEs 115 in inactive or idle mode that are monitoring the corresponding multicast service based on the number of service request messages received for each multicast service. In some cases, the base station 105-a may receive several feedback messages 220 and may determine the number of UEs 115 in inactive or idle mode. The base station 105-a may compare the number of feedback messages to the number of UEs 115 to determine whether to retransmit one or more multicast messages.

[0096] In some examples, base station 105-a may not configure an identifier, such as a radio network temporary identifier (RNTI) or a cell RNTI (C-RNTI), for UE 115-b that is in an inactive or idle mode for communicating with base station 105-a. In order for base station 105-a to identify which UE 115 has transmitted the service request message, UE 115-b may use an identifier of UE 115-b to transmit the service request message. For example, UE 115-b may hash the service request message with a device identifier of UE 115-b (e.g., based on a hash function or hash code corresponding to the device identifier) ​​and transmit the hashed service request message to base station 105-a.

[0097] In some examples, in order to reduce system overhead, the base station 105-a may not count every inactive UE 115 or idle UE 115. Alternatively, the base station 105-a may configure each inactive UE 115 or idle UE 115 to have a probability indicator. In some examples, a percentage (such as 1%, 2%, 5%, or 10%, etc.) associated with the probability of transmitting multicast feedback may represent or represent each probability indicator. Each UE 115 may transmit a service request message within one or more counting durations. In some cases, the UE 115 may transmit a service request message based on the probability indicator. For example, each UE 115 may consider the probability indicator when determining whether to transmit a service request message. As an example, for every 100 counting durations, a UE 115 (such as UE 115-b) with a probability indicator of 10% may transmit 10% of the time (for example, UE115-b may transmit a service request message in 10 counting durations of the 100 counting durations). This may enable the base station 105-a to count the UEs 115 transmitting service request messages and use the probability indicator to estimate the total number of UEs 115 that the base station 105-a can support. In some cases, the total number of UEs 115 may include UEs in connected mode and UEs in inactive mode.

[0098] Figure 3 An example of a wireless communication system 300 that supports feedback for multicast transmissions according to aspects of the present disclosure is illustrated. In some examples, the wireless communication system 300 can implement aspects of the wireless communication system 100 or 200. The wireless communication system 300 can include a UE 115 and a base station 105, which can be as described with reference to Figure 1 Corresponding examples of UE 115 and base station 105 are described.

[0099] The wireless communication system 300 may support multiple TA commands for use by UEs 115 to transmit feedback for a multicast message when in an inactive or idle mode. In some implementations, the base station 105-b may determine that a UE in an inactive or idle mode may use a TA command set, transmit a TA command to one or more UEs 115, and receive feedback from one or more UEs 115 based on the TA commands in the TA command set.

[0100] In some implementations, the base station 105-b may determine one or more TA commands based on a number of factors. These factors may include historical data or information (such as previously configured TA commands), information associated with neighboring or serving cells (e.g., relative delays between the serving cell and one or more neighboring cells), information from other wireless devices (such as other UEs) in the wireless communication system 300, RSRP, the geographic location or terrain in which the wireless communication system 300 operates, or the location of the UE 115, etc.

[0101] For example, base station 105-b may determine a first TA command for UE 115 (such as UE 115-f) based on the positioning of UE 115-f relative to base station 105-b or base station 105-c, or both. Base station 105-c may determine a TA command for UE 115 (such as UE 115-e) based on the positioning of UE 115-e relative to base station 105-b or base station 105-c, or both, and base station 105-c may determine a TA command for UE 115 (such as UE 115-d) based on the positioning of UE 115-d relative to base station 105-c or base station 105-d, or both.

[0102] In some implementations, the base station 105-b (or another base station 105 in the wireless communication system 300) may determine a set of TA commands based on a set of channel metrics or system conditions, such as geographic location, environment, terrain, number of users, number and location of interfering objects (such as buildings), etc. For example, the base station 105-b may provide a TA command with a TA value corresponding to one or more channel metrics or locations between the UE 115-f and one or more cells, such as a serving cell (which may be supported by the base station 105-b), a neighboring cell (which may be supported by the base station 105-c), or both. For example, the base station 105-b may configure TA command 0 for use by a UE 115-f in an inactive or idle mode if the serving cell RSRP (which the base station 105-b may support) is within the [X00, Y00] dB range, the neighbor cell 1 RSRP (which the base station 105-c may support) is within the [X01, Y01] dB range, and the neighbor cell 2 RSRP (which the base station 105-d may support) is within the [X02, Y02] dB range, etc. The base station 105-b may also configure TA command 1 for another set of channel metrics if the serving cell RSRP is within the [X10, Y10] dB range, the neighbor cell 1 RSRP is within the [X11, Y11] dB range, and the neighbor cell 2 RSRP is within the [X12, Y12] dB range.

[0103] In some examples, the base station 105-b (or another base station 105 in the wireless communication system 300) may configure one or more TA commands based on a relative delay between a serving cell and a neighboring cell. For example, the base station 105-b may configure a first TA command when the relative delay between a serving cell (that the base station 105-b may support) and a neighboring cell (such as a neighboring cell that the base station 105-c may support) is within a time range of [0, T0], and configure a second TA command when the relative delay between a serving cell (that the base station 105-b may support) and a neighboring cell (such as a neighboring cell that the base station 105-c may support) is within a time range of [T0, T1], and so on.

[0104] In some implementations, the base station 105-b (or another base station 105 in the wireless communication system 300) may configure one or more TA commands based on the positioning range. For example, the base station 105-b may configure a first TA command for the UE 115-f when the UE 115-f is within the positioning range 0, configure a second TA command for the UE 115-f when the UE 115-f is within the positioning range 1, and so on.

[0105] The base station 105-b may determine a set of TA commands based on channel metrics, positioning, or other conditions, and may broadcast the set of TA commands to the UE 115. In some examples, the base station 105-b may transmit a set of TA commands and values ​​via a feedback configuration message 215, as described with reference to Figure 2 Described. A UE 115 (e.g., UE 115-f) in an inactive mode or an idle mode may receive a TA command set and may determine a channel metric, location, or other condition of the UE 115-f. The UE 115-f may determine a TA command based on the determined channel metric, location, or other condition, and may use the TA command to transmit a feedback message for multicast communication when in an inactive or idle mode. For example, the UE 115-f may measure a channel metric set and apply a TA value corresponding to a TA command associated with the measured channel metric based on the measured channel metric to transmit a feedback message. In some cases, the UE 115-f may transmit the feedback message via the PUCCH.

[0106] When the channel metrics, positioning or other conditions of the devices within the wireless communication system 300 change, the UE 115 transmitting feedback for multicast communication while in an inactive or idle mode may use different TA commands. For example, the UE 115-f may move within the coverage area of ​​the base station 105-b, or environmental conditions, the number of active users, or other factors may change. Accordingly, the UE 115-f may periodically re-evaluate the current conditions (e.g., the UE 115-f may re-measure the channel metric set), and the TA command may be determined based on the current conditions. As an example, the UE 115-f may change its positioning relative to the base station 105-b and the base station 105-c, and the TA command corresponding to the new positioning of the UE 115-f may be applied to subsequent feedback messages for multicast communication when the UE 115-f is in an inactive or idle mode.

[0107] Figure 4 An example of a wireless communication system 400 that supports feedback for multicast transmissions according to aspects of the present disclosure is illustrated. In some examples, the wireless communication system 400 can implement aspects of the wireless communication systems 100, 200, or 300. The wireless communication system 400 can include a UE 115-g and a base station 105-e, which can be referenced Figure 1 Examples of UE 115 and base station 105 are described.

[0108] The UE may determine a TA command or TA value based on different channel metrics or positioning information for UEs 115 within the system, which may be computationally complex, may be associated with high signaling overhead, or may consume storage or other resources at the UE. To reduce signaling overhead, storage limitations, and other issues, the wireless communication system 400 may support neural network modeling for determining TA commands. For example, the base station 105-e may utilize a neural network model and determine an associated set of neural network parameters to determine one or more TA commands. The UE 115-g may use the one or more TA commands to transmit feedback for multicast communications when in an inactive or idle mode.

[0109] In some implementations, the base station 105-e may determine a neural network modeling algorithm representing a statistical model for TA commands based on the neural network modeling algorithm and other data available at the base station 105-e. For example, the base station 105-e may utilize historical data (previously configured TA values, positioning data of the UE 115-g or other UEs, etc.) or information from neighboring devices or cellular cells to calculate the TA command set (such as reference Figure 34. In some implementations, the base station 105-a may indicate or the UE 115-g may determine parameters (such as channel metrics or positioning information), and the base station 105-e may base the neural network model on these parameters. For example, the base station 105-e may indicate a neural network model, a set of neural network parameters, or both to the UE 115-g via the communication link 410. The UE 115-g may determine input parameters (such as channel metrics measured at the UE 115-g, positioning information at the UE 115-g, etc.) and use the neural network model and neural network parameters that the base station 105-e may indicate to determine a TA command to be used to transmit feedback for the multicast communication. After receiving the multicast message via the communication link 410, the UE 115-g may use the determined TA command to transmit a feedback message (such as a reference to Figure 2 Described feedback message 220).

[0110] As an example, at 420, the base station 105-e may determine a neural network model that the base station 105-e may base the neural network model on based on static (elevation angle, terrain, or base station location, etc.) and dynamic (weather, RSRP, or UE location, etc.) conditions. These conditions may be parameters for the model and may correspond to a TA command set, such as reference Figure 3 At 425, the base station 105-e may determine parameters for the neural network model, which may represent the TA command. At 430, the base station 105-e may transmit an indication of the neural network model and the neural network parameters to the UE 115-g via the communication link 410. In some examples, the base station 105-e may transmit the neural network model and the neural network parameters along with the TA command for the UE 115-g in the active or connected mode, or the base station 105-e may include the neural network model and the neural network parameters in a configuration message (such as a reference to Figure 2 The feedback configuration message 215 described in the description.

[0111] At 435, the UE 115-g may receive the neural network model and the neural network parameters, and based on the neural network model and the neural network parameters, may determine a TA command to be used to transmit feedback for multicast communications while in an inactive or idle mode at 440. In some examples, at 440, the UE 115-g may determine UE-specific parameters to be input to the model (e.g., the UE 115-g may measure channel metrics, current positioning), and at 445, the UE 115-g may transmit feedback to the base station 105-e based on the determined TA value.

[0112] At various times and for various reasons, UE 115-g may transition from an inactive or idle mode to an active or connected mode while UE 115-g may receive updated neural network models and neural network parameters from base station 105-e. UE 115-g may base the updated models and parameters on additional data accumulated, analyzed, or otherwise processed while UE 115-g was in the inactive or idle mode.

[0113] Figure 5 An example of a process flow 500 for supporting feedback for multicast transmissions according to aspects of the present disclosure is illustrated. In some examples, the process flow 500 can implement aspects of the wireless communication system 100, 200, 300, or 400. The process flow 500 can include a UE 115-h and a base station 105-f, which can be respective examples of a UE 115 and a base station 105. The following alternative examples can be implemented, in which some of the processes are performed in a different order than described or not performed at all. In some implementations, each process can include additional features not mentioned below, or further processes can be added.

[0114] At 505, the UE 115-h may optionally transmit an indication of channel quality information to the base station 105-f, which may include one or more channel metrics measured by the UE 115-h. For example, the UE 115-h may indicate signal strength, angle, beam identification, or location of the UE 115-h.

[0115] At 510, the base station 105-f may optionally determine resources for the UE 115-h to use for transmitting feedback for multicast communications when the UE 115-h is in an inactive or idle mode. In some implementations, the base station 105-f may determine the resources based on a channel metric. The resources may be PRACH resources or preambles, PUCCH resources, etc. In some examples, the base station 105-f may determine a set of resources (e.g., a resource pool) to designate for feedback transmissions from the UE 115-h.

[0116] In some examples, base station 105-f may determine one or more TA commands for UE 115-h at 515. Base station 105-f may base the TA commands on channel metrics (e.g., channel quality information transmitted at 505). For example, each TA command may correspond to a set of channel metrics and a corresponding TA value.

[0117] At 520, the base station 105-f may transmit a feedback configuration message to the UE 115-h. The feedback configuration message may be as described in reference to Figure 2An example of a feedback configuration message 215 is described. In some examples, the feedback configuration message may include the one or more TA commands determined at 515. Additionally or alternatively, the feedback configuration message may include an indication of the resources determined at 510.

[0118] The base station 105-f may optionally transmit the determined TA command to the UE 115-h at 525. For example, the base station 105-f may optionally transmit one or more TA commands at 525 without including a TA command in the feedback configuration message at 520.

[0119] At 530, the base station 105-f may optionally transmit an indication of or associated with a neural network model and neural network parameters used to determine the TA command or TA value. For example, in some implementations, the base station 105-f may utilize a neural network to determine the one or more TA commands (e.g., at 515), and in such cases, the base station 105-f may determine a neural network model and associated parameters that the base station 105-f may use to calculate the TA command or TA value for use by the UE 115-h in transmitting feedback for multicast communications when in an inactive or idle mode. The base station 105-f may determine the neural network model based on historical data or other parameters.

[0120] At 535, the UE 115-h may determine a TA command or TA value to be used to transmit feedback for the multicast communication. In some implementations, the UE 115-h may use a neural network model, neural network parameters, and (in some cases) UE-specific parameters to determine a TA command to be used for multicast feedback when in an inactive or idle mode. In other examples, the base station 105-f may transmit one or more TA commands at 525, and the UE 115-h may use the one or more TA commands to determine a TA value to be used for multicast feedback.

[0121] At 540, the UE 115-h may monitor for multicast communications from the base station 105-f. In some cases, the base station 105-f may transmit a multicast control channel via a set of resources allocated for multicast communications. The multicast control channel may indicate scheduling information about the multicast communications. If the UE 115-h successfully receives the multicast control channel, the UE 115-h may determine the resources scheduled for multicast communications and may monitor the determined resources for multicast communications from the base station 105-f at 545.

[0122] Optionally, the UE 115-h may determine resources to be used to transmit the feedback message to the base station 105-f in response to the multicast communication at 550. For example, the UE 115-h may determine the resources based on channel metrics, or the base station 105-f may transmit a feedback configuration message that may indicate the resources at 520. The resources may include PRACH resources or preambles, PUCCH resources, etc.

[0123] At 555, the base station 105-f may monitor the multicast control channel for a feedback message from the UE 115-h. At 560, the UE 115-h may transmit the feedback message to the base station 105-f on the multicast control channel and using the determined resources.

[0124] Figure 6 An example of a process flow 600 for supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is illustrated. In some examples, the process flow 600 can implement aspects of the wireless communication system 100, 200, 300, or 400. The process flow 600 can include a UE 115-i and a base station 105-g, which can be respective examples of a UE 115 and a base station 105. The following alternative examples can be implemented, in which some of the processes are performed in a different order than described or not performed at all. In some implementations, each process can include additional features not mentioned below, or further processes can be added.

[0125] At 605, the base station 105-g may optionally determine resources for the UE 115-f to use for the feedback message. In some implementations, the base station 105-g may determine the resources based on a channel metric. The resources may be PRACH resources or preambles, PUCCH resources, etc. In some examples, the base station 105-g may determine a set of resources (e.g., a resource pool) to designate for feedback transmissions from the UE 115-i.

[0126] At 610, the base station 105-g may transmit a feedback configuration message to the UE 115-i. The feedback configuration message may be as described with reference to Figure 2 An example of a feedback configuration message 215 is described. In some examples, the feedback configuration message may include an indication of the resources determined at 605. The feedback configuration message may include an indication to cause the UE 115-i to transmit a reception status report. In other examples, the base station 105-g may transmit the indication to cause the UE 115-i to transmit a reception status report in a message separate from the feedback configuration message.

[0127] In some implementations, at 615 , UE 115 - i may monitor via one or more multicast opportunities for one or more multicast communications.

[0128] The base station 105-g may transmit one or more physical control channels for multicast communications during the one or more multicast opportunities at 620. The physical control channels for multicast communications may include scheduling information regarding the multicast messages.

[0129] At 625, UE 115-i may transmit a reception status report to base station 105-g. The reception status report may include a number of physical control channels for multicast communications decoded at UE 115-i, a number of multicast opportunities monitored by UE 115-i, a ratio between the number of physical control channels received and the number of physical control channels transmitted by base station 105-g, and the like.

[0130] At 630, base station 105-g may transmit a counting duration indication to UE 115-i, the counting duration indication specifying a counting duration for one or more services of multicast communications supported by base station 105-g. In some examples, the counting duration indication may include an indication of a resource or resource pool for UE 115-i to transmit a service request message in response to base station 105-g during the counting duration.

[0131] The base station 105-g may optionally transmit a probability indicator to the UE 115-i at 635. The probability indicator may specify a probability that the UE 115-i transmits a service request message as a response during the counting duration.

[0132] At 640, UE 115-i may transmit a service request message indicating interest in receiving the service in response to the count duration indication transmitted at 630. UE 115-i may transmit the service request message on the indicated resource or resource pool, and in some examples, may transmit the service request message based on the probability indicator received at 635.

[0133] At 645, the base station 105-g may determine the number of UEs requesting the given multicast service. For example, the base station 105-g may monitor service request messages from one or more UEs, including UE 115-i, for a counting duration and determine the number of UEs (inactive or otherwise) requesting the given multicast service. In some implementations, the base station 105-g may determine the number of UEs based on a probability indicator transmitted at 635. For example, if the probability indicator is 1%, and the base station 105-g receives 1 service request message (e.g., from UE 115-i) at 640, the base station 105-g may determine that because only 1% of the UEs (according to the probability indicator) transmitted service request messages, approximately 100 UEs are requesting the multicast service.

[0134] Figure 7A block diagram of a device 705 supporting feedback for a multicast transmission according to aspects of the present disclosure is shown. The device 705 may be an example of aspects of a UE 115. The device 705 may include a receiver 710, a communication manager 715, and a transmitter 720. The communication manager 715 may be implemented at least in part by one or both of a modem and a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0135] 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 feedback for multicast transmissions). The information may be passed to other components of the device 705. The receiver 710 may be a reference Figure 8 Examples of aspects of a transceiver are described. Receiver 710 may utilize a single antenna or a collection of antennas.

[0136] The communication manager 715 may receive from a base station one or more configurations for a UE to provide feedback associated with a multicast transmission from the base station when in an inactive mode or an idle mode, monitor, by the UE, a set of time-frequency resources configured for multicast transmission from the base station when in an inactive mode or an idle mode, and transmit, by the UE, one or more multicast feedback messages according to the one or more configurations based on the monitoring when in an inactive mode or an idle mode. The communication manager 715 may be an example of aspects of the communication manager 815 described herein.

[0137] The transmitter 720 may transmit signals generated by other components of the device 705. In some examples, the transmitter 720 may be co-located with the receiver 710 in a transceiver component. For example, the transmitter 720 may be a reference Figure 8 Examples of aspects of a transceiver are described. Transmitter 720 may utilize a single antenna or a collection of antennas.

[0138] In some examples, the communication manager 715 may be implemented as an integrated circuit or chipset for a mobile device modem, and the receiver 710 and transmitter 720 may be implemented as analog components (e.g., amplifiers, filters, antennas) coupled to the mobile device modem to enable wireless transmission and reception on one or more frequency bands.

[0139] The communication manager 715 may be implemented to achieve one or more potential advantages. One implementation may allow the device 705 to provide feedback for multicast communications while in an inactive or idle mode or in other scenarios where the device 705 does not have an effective or configured TA to use for transmitting feedback. Based on the technology for multicast feedback between the device 705 and the base station, the device 705 may be able to provide feedback that it may not otherwise be able to provide without having to transition to a connected mode to obtain an effective TA, which may utilize limited resources at the device 705, such as power and battery life. The ability to transmit feedback for multicast communications in an idle or inactive mode may also increase the likelihood of successfully receiving retransmissions.

[0140] Figure 8 A block diagram of a device 805 supporting feedback for a multicast transmission according to aspects of the present disclosure is shown. The device 805 may be an example of aspects of the device 705 or the UE 115. The device 805 may include a receiver 810, a communication manager 815, and a transmitter 835. The communication manager 815 may be implemented at least in part by one or both of a modem and a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0141] The receiver 810 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to feedback for multicast transmissions). The information may be passed to other components of the device 805. The receiver 810 may be a reference Figure 8 Examples of aspects of a transceiver are described. Receiver 810 may utilize a single antenna or a collection of antennas.

[0142] The communication manager 815 may be an example of aspects of the communication manager 715. The communication manager 815 may include a configuration receiver 820, a multicast monitor 825, and a feedback transmitter 830.

[0143] Configuration receiver 820 may receive one or more configurations from a base station for use by a UE to provide feedback associated with a multicast transmission from the base station while in an inactive mode or an idle mode.

[0144] The multicast monitor 825 may be used by the UE to monitor a set of time-frequency resources configured for multicast transmissions from a base station when the UE is in an inactive mode or an idle mode.

[0145] The feedback transmitter 830 may transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring by the UE while in an inactive mode or an idle mode.

[0146] The transmitter 835 can transmit signals generated by other components of the device 805. In some examples, the transmitter 835 can be co-located with the receiver 810 in a transceiver component. For example, the transmitter 835 can be a reference Figure 8 Examples of various aspects of a transceiver are described. Transmitter 835 may utilize a single antenna or a collection of antennas.

[0147] Fig. 9 A block diagram of a communication manager 905 supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown. The communication manager 905 may include a configuration receiver 910, a multicast monitor 915, a feedback transmitter 920, a resource manager 925, a preamble selector 930, a channel quality transmitter 935, a format component 940, a TA receiver 945, a measurement component 950, a neural network receiver 955, a TA component 960, a status report transmitter 965, an indication transmitter 970, a broadcast receiver 975, a message transmitter 980, and a probability receiver 985. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0148] Configuration receiver 910 may receive one or more configurations from a base station for a UE to use in providing feedback associated with a multicast transmission from a base station when in an inactive mode or an idle mode. In some examples, configuration receiver 910 may receive system information or a multicast control channel indicating the one or more configurations.

[0149] The multicast monitor 915 may be used by the UE to monitor a set of time-frequency resources configured for multicast transmission from a base station when in an inactive mode or an idle mode. In some examples, the multicast monitor 915 may receive a multicast message on the set of time-frequency resources based on the monitoring, wherein selecting a preamble from the set of RACH preambles includes selecting a preamble based on a channel quality metric associated with the received multicast message.

[0150] In some examples, the multicast monitor 915 may receive a multicast message on a set of time-frequency resources based on monitoring. In some examples, the multicast monitor 915 may monitor multiple opportunities to find multicast transmissions from a base station. In some examples, the multicast monitor 915 may receive a set of physical control channels for multicast transmissions based on monitoring multiple opportunities.

[0151] The feedback transmitter 920 may transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring by the UE when in an inactive mode or an idle mode. In some examples, the feedback transmitter 920 may fill the payload of the one or more multicast feedback messages based on a size associated with an uplink control format. In some examples, the feedback transmitter 920 may transmit the one or more multicast feedback messages based on the absence of receiving a multicast transmission on a set of time-frequency resources during the monitoring period, wherein the one or more multicast feedback messages include a negative acknowledgement feedback message.

[0152] In some examples, the feedback transmitter 920 may transmit the one or more multicast feedback messages based on receiving a multicast transmission on the set of time-frequency resources during the monitoring period, wherein the one or more multicast feedback messages include an acknowledgement feedback message. In some examples, the feedback transmitter 920 may refrain from transmitting the one or more multicast feedback messages based on a timing advance value of the UE.

[0153] The resource manager 925 may determine a set of RACH resources available for multicast feedback based on the resource allocation indicated by the one or more configurations, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages via the set of RACH resources. In some examples, the resource manager 925 may determine a set of RACH preambles available for multicast feedback based on the resource allocation indicated by the one or more configurations.

[0154] In some examples, the resource manager 925 may determine a set of time-frequency resources for multicast feedback based on the channel quality information, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages via the determined time-frequency resources. In some examples, the resource manager 925 may determine a resource pool available for multicast feedback based on the one or more configurations, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using a subset of time-frequency resources in the resource pool.

[0155] In some examples, the resource manager 925 may determine a set of PUCCH resources available for multicast feedback based on the one or more configurations, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using a subset of the PUCCH resources. In some examples, the resource manager 925 may determine a set of uplink resources available for a reception status report associated with a multicast transmission from a base station. In some implementations, the set of uplink resources includes RACH resources or uplink control channel resources.

[0156] The preamble selector 930 may select a preamble from the set of RACH preambles, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using the selected preamble.

[0157] The channel quality transmitter 935 may transmit channel quality information associated with the received multicast message. In some implementations, the channel quality information includes one or more of: reference signal received power, beam direction, beam width, geographic location, or altitude and azimuth values ​​associated with one or more beams.

[0158] Format component 940 can determine an uplink control format for the one or more multicast feedback messages.

[0159] The TA receiver 945 may receive a timing advance command from a base station, the timing advance command indicating a timing advance for use by the UE when in an inactive mode or an idle mode, wherein the timing advance command corresponds to a first set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE. In some examples, the TA receiver 945 may receive a second timing advance command from a base station, the second timing advance command indicating a second timing advance for use by the UE when in an inactive mode or an idle mode, wherein the second timing advance command corresponds to a second set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE. In some examples, the TA receiver 945 may receive one or more of the timing advance command or the second timing advance command in one or more configurations indicating a set of uplink resources for multicast feedback, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using the set of uplink resources. In some implementations, the one or more channel metrics include one or more of: reference signal received power, relative delay between a serving cell and one or more other cells, or a positioning range of the UE.

[0160] The measurement component 950 may measure a set of channel metrics of the one or more cellular cells including the serving cellular cell, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using a timing advance based on the channel metric set satisfying a first set of values ​​or using a second timing advance based on the channel metric set satisfying a second set of values.

[0161] The neural network receiver 955 may receive a neural network parameter set in a timing advance command from a base station, wherein the neural network parameter set indicates a timing advance. In some examples, the neural network receiver 955 may receive a neural network model and a neural network parameter set from a base station at a UE when in a connected mode, the neural network model and the neural network parameter set being associated with a neural network for timing advance. In some examples, the neural network receiver 955 may receive one or more neural network parameters from a base station.

[0162] The TA component 960 may determine a timing advance based on a neural network model, a neural network parameter set, and the one or more neural network parameters, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages based on the timing advance by the UE when in an inactive mode or an idle mode.

[0163] The status report transmitter 965 may use the uplink resource set to transmit the reception status report.

[0164] The indication transmitter 970 may transmit in the reception status report an indication of the number of received sets of physical control channels for multicast transmissions. In some examples, the indication transmitter 970 may transmit in the reception status report a ratio between the number of received sets of physical control channels for multicast transmissions and a total amount of physical control channels for multicast transmissions transmitted on multiple occasions. In some implementations, the total amount of physical control channels for multicast transmissions corresponds to a set of uplink control channel resources.

[0165] The broadcast receiver 975 may receive a broadcast message from a base station indicating a count duration for a service of a multicast transmission supported by the base station.

[0166] The message transmitter 980 may transmit a message requesting a service of a multicast transmission supported by the base station within a count duration. In some examples, the message transmitter 980 may transmit the message based on an identifier of the UE. In some examples, the message transmitter 980 may transmit the message based on a probability indicator. In some implementations, the message includes an uplink control channel message or a RACH message.

[0167] The probability receiver 985 may receive a probability indicator for the UE from the base station.

[0168] Fig.10A diagram of a system including a device 1005 supporting feedback for multicast transmissions according to aspects of the present disclosure is shown. The device 1005 may be an example of or include a component of the device 705, device 805, or UE 115. The device 1005 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 1010, an I / O controller 1015, a transceiver 1020, an antenna 1025, a memory 1030, and a processor 1040. These components may be in electronic communication via one or more buses (e.g., bus 1045).

[0169] The communication manager 1010 may receive one or more configurations from a base station for a UE to use in providing feedback associated with a multicast transmission from the base station when the UE is in an inactive mode or an idle mode, monitor a set of time-frequency resources configured for the multicast transmission from the base station when the UE is in an inactive mode or an idle mode, and transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring by the UE when the UE is in an inactive mode or an idle mode.

[0170] I / O controller 1015 can manage input and output signals of device 1005. I / O controller 1015 can also manage peripheral devices that are not integrated into device 1005. In some implementations, I / O controller 1015 can represent a physical connection or port to an external peripheral device. In some implementations, I / O controller 1015 can utilize an operating system, such as or another known operating system. In other cases, the I / O controller 1015 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some implementations, the I / O controller 1015 may be implemented as part of the processor. In some implementations, a user may interact with the device 1005 via the I / O controller 1015 or via hardware components controlled by the I / O controller 1015.

[0171] The transceiver 1020 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1020 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1020 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0172] In some implementations, device 1005 may include a single antenna 1025, or device 1005 may have more than one antenna 1025, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0173] The memory 1030 may include random access memory (RAM) and read-only memory (ROM). The memory 1030 may store computer-readable, computer-executable code 1035 including instructions that, when executed, cause the processor to perform various functions described herein. In some implementations, the memory 1030 may include, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0174] Processor 1040 may include an intelligent hardware device (e.g., a general purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some implementations, processor 1040 may be configured to operate a memory array using a memory controller. In other cases, the memory controller may be integrated into processor 1040. Processor 1040 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1030) to cause device 1005 to perform various functions (e.g., functions or tasks to support feedback for multicast transmission).

[0175] The code 1035 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1035 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some implementations, the code 1035 may not be directly executable by the processor 1040, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0176] Fig.11 A block diagram of a device 1105 supporting feedback for a multicast transmission according to aspects of the present disclosure is shown. The device 1105 may be an example of aspects of a base station 105. The device 1105 may include a receiver 1110, a communication manager 1115, and a transmitter 1120. The communication manager 1115 may be implemented at least in part by one or both of a modem and a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0177] 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 feedback for multicast transmissions). The information may be passed to other components of the device 1105. The receiver 1110 may be a reference Fig.12 Examples of various aspects of a transceiver are described. Receiver 1110 may utilize a single antenna or a collection of antennas.

[0178] The communication manager 1115 may transmit to the UE one or more configurations for multicast feedback by the UE in an inactive mode or an idle mode, transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communication, and monitor for one or more multicast feedback messages from the UE according to the one or more configurations based on transmitting the one or more multicast transmissions. The communication manager 1115 may be an example of aspects of the communication manager 1215 described herein.

[0179] The transmitter 1120 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1120 may be co-located with the receiver 1110 in a transceiver component. For example, the transmitter 1120 may be a reference Fig.12 Examples of various aspects of a transceiver are described. Transmitter 1120 may utilize a single antenna or a collection of antennas.

[0180] Fig.12 A block diagram of a device 1205 supporting feedback for a multicast transmission according to aspects of the present disclosure is shown. The device 1205 may be an example of aspects of the device 1105 or base station 105. The device 1205 may include a receiver 1210, a communication manager 1215, and a transmitter 1235. The communication manager 1215 may be implemented at least in part by one or both of a modem and a processor. Each of these components may be in communication with each other (e.g., via one or more buses).

[0181] Receiver 1210 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 feedback for multicast transmissions). The information may be passed to other components of device 1205. Receiver 1210 may be a reference Fig.12 Examples of various aspects of a transceiver are described. Receiver 1210 may utilize a single antenna or a collection of antennas.

[0182] The communication manager 1215 may be an example of aspects of the communication manager 1115. The communication manager 1215 may include a configuration transmitter 1220, a multicast transmitter 1225, and a feedback monitor 1230. The communication manager 1215 may be an example of aspects of other communication managers described herein.

[0183] Configuration transmitter 1220 may transmit one or more configurations to a UE for multicast feedback by the UE in an inactive mode or an idle mode.

[0184] The multicast transmitter 1225 may transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communications.

[0185] Feedback monitor 1230 may monitor for one or more multicast feedback messages from the UE based on transmitting the one or more multicast transmissions in accordance with the one or more configurations.

[0186] The transmitter 1235 may transmit signals generated by other components of the device 1205. In some examples, the transmitter 1235 may be co-located with the receiver 1210 in a transceiver component. Fig.12 Examples of various aspects of a transceiver are described. The transmitter 1235 may utilize a single antenna or a collection of antennas.

[0187] Fig.13 A block diagram of a communication manager 1305 supporting feedback for multicast transmissions in accordance with aspects of the present disclosure is shown. The communication manager 1305 may include a configuration transmitter 1310, a multicast transmitter 1315, a feedback monitor 1320, a resource transmitter 1325, a channel quality receiver 1330, a resource pool component 1335, a TA transmitter 1340, a neural network transmitter 1345, a report receiver 1350, a broadcast transmitter 1355, a service monitor 1360, and a probability transmitter 1365. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses).

[0188] Configuration transmitter 1310 may transmit one or more configurations to a UE for multicast feedback by the UE in an inactive mode or an idle mode. In some examples, configuration transmitter 1310 may transmit system information or a multicast control channel indicating the one or more configurations.

[0189] The multicast transmitter 1315 may transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communications.

[0190] The feedback monitor 1320 may monitor one or more multicast feedback messages from the UE according to one or more configurations based on transmitting one or more multicast transmissions. In some examples, the feedback monitor 1320 may monitor a set of RACH resources to find the one or more multicast feedback messages. In some aspects, the feedback monitor 1320 may monitor based on a set of RACH preambles to find the one or more multicast feedback messages. In some implementations, the feedback monitor 1320 may receive the one or more multicast feedback messages based on monitoring a subset of time-frequency resources in a resource pool. In some examples, the feedback monitor 1320 may monitor a set of PUCCH resources to find the one or more multicast feedback messages.

[0191] In some examples, the feedback monitor 1320 may receive the one or more multicast feedback messages based on monitoring that a set of channel metrics at the UE satisfies a first set of values ​​according to a timing advance or that a set of channel metrics at the UE satisfies a second set of values ​​according to a second timing advance. In some aspects, the feedback monitor 1320 may receive the one or more multicast feedback messages via a set of uplink resources. In some implementations, the feedback monitor 1320 may receive the one or more multicast feedback messages from a UE in an inactive mode or an idle mode based on a timing advance, the timing advance being based on the one or more neural network parameters. In some examples, the feedback monitor 1320 may receive the one or more multicast feedback messages based on monitoring, wherein the one or more multicast feedback messages include a negative acknowledgement feedback message. In some aspects, the feedback monitor 1320 may receive the one or more multicast feedback messages based on monitoring, wherein the one or more multicast feedback messages include an acknowledgement feedback message.

[0192] The resource transmitter 1325 may transmit an indication of a set of RACH resources available for multicast feedback in the one or more configurations. In some examples, the resource transmitter 1325 may transmit an indication of a set of RACH preambles available for multicast feedback in the one or more configurations. In some implementations, the resource transmitter 1325 may transmit an indication of a resource pool in the one or more configurations. In some examples, the resource transmitter 1325 may transmit an indication of a set of PUCCH resources available for multicast feedback in the one or more configurations. In some aspects, the resource transmitter 1325 may transmit an indication of a set of uplink resources in the one or more configurations.

[0193] The channel quality receiver 1330 may receive channel quality information associated with a multicast channel used for multicast communications with the UE from the UE. In some examples, the channel quality information includes one or more of: reference signal received power, beam direction, beam width, geographic location, or altitude and azimuth values ​​associated with one or more beams. In some aspects, the one or more channel metrics include one or more of: reference signal received power, relative delay between the serving cell and one or more other cells, or a positioning range of the UE.

[0194] Resource pool component 1335 can determine a resource pool for multicast feedback to the UE based on the channel quality information.In some examples, resource pool component 1335 can determine a set of uplink resources available for reception status reports associated with multicast transmissions from a base station.

[0195] The TA transmitter 1340 may transmit a timing advance command to a UE, the timing advance command indicating a timing advance for a UE in an inactive mode or an idle mode, wherein the timing advance command corresponds to a first set of values ​​of one or more channel metrics associated with the UE and associated with one or more cellular cells including a serving cellular cell for the UE.

[0196] In some examples, the TA transmitter 1340 may transmit a second timing advance command to the UE, the second timing advance command indicating a second timing advance for the UE in an inactive mode or an idle mode, wherein the second timing advance command corresponds to a second set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE. In some implementations, the TA transmitter 1340 may transmit one or more of the timing advance command or the second timing advance command in the one or more configurations, wherein the one or more configurations indicate a set of uplink resources for multicast feedback.

[0197] Neural network transmitter 1345 may transmit a neural network parameter set to a UE, wherein the neural network parameter set indicates a timing advance. In some examples, neural network transmitter 1345 may transmit a neural network model and a neural network parameter set associated with a neural network for timing advance to a UE in a connected mode. In some examples, neural network transmitter 1345 may transmit one or more neural network parameters to a UE.

[0198] The report receiver 1350 may receive a reception status report from the UE on the uplink resource set. In some examples, the report receiver 1350 may receive in the reception status report a number of physical control channels for multicast transmissions received by the UE. In some examples, the report receiver 1350 may receive in the reception status report a ratio between the number of physical control channels for multicast transmissions received by the UE and a total amount of physical control channels for multicast transmissions transmitted on multiple occasions of the uplink control channel resource set. In some implementations, the uplink resource set includes RACH resources or uplink control channel resources.

[0199] The broadcast transmitter 1355 may transmit a broadcast message indicating a count duration for a service for a multicast transmission indicated by the base station.

[0200] The service monitor 1360 may monitor one or more messages from the UE requesting a service supported by the multicast transmission of the base station during the counting duration. In some examples, the service monitor 1360 may receive the one or more messages based on an identifier of the UE. In some examples, the service monitor 1360 may receive the one or more messages based on a probability indicator of the UE. In some implementations, the one or more messages include an uplink control channel message or a RACH message.

[0201] The probability transmitter 1365 may transmit a probability indicator for the UE to the UE.

[0202] Fig.14 A diagram of a system including a device 1405 supporting feedback for multicast transmissions according to aspects of the present disclosure is shown. Device 1405 may be an example of device 1105, device 1205, or base station 105 or include a component of device 1105, device 1205, or base station 105. Device 1405 may include components for two-way voice and data communications, including components for transmitting and receiving communications, including a communication manager 1410, a network communication manager 1415, a transceiver 1420, an antenna 1425, a memory 1430, a processor 1440, and an inter-station communication manager 1445. These components may be in electronic communication via one or more buses (e.g., bus 1450).

[0203] The communication manager 1410 may transmit one or more configurations to the UE for multicast feedback by the UE in an inactive mode or an idle mode, transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communication, and monitor one or more multicast feedback messages from the UE according to the one or more configurations based on transmitting the one or more multicast transmissions.

[0204] The network communications manager 1415 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1415 may manage the delivery of data communications for client devices, such as one or more UEs 115.

[0205] The transceiver 1420 may communicate bidirectionally via one or more antennas, wired or wireless links, as described above. For example, the transceiver 1420 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. The transceiver 1420 may also include a modem to modulate packets and provide the modulated packets to an antenna for transmission, and demodulate packets received from an antenna.

[0206] In some implementations, device 1405 may include a single antenna 1425, or device 1405 may have more than one antenna 1425, which may be capable of transmitting or receiving multiple wireless transmissions concurrently.

[0207] The memory 1430 may include RAM, ROM, or a combination thereof. The memory 1430 may store computer readable code 1435 including instructions that, when executed by a processor (e.g., processor 1440), cause the device to perform various functions described herein. In some implementations, the memory 1430 may include, among other things, a BIOS that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0208] Processor 1440 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 implementations, processor 1440 may be configured to operate a memory array using a memory controller. In some implementations, the memory controller may be integrated into processor 1440. Processor 1440 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1430) to cause device 1405 to perform various functions (e.g., functions or tasks to support feedback for multicast transmission).

[0209] The inter-site communication manager 1445 may manage communications with other base stations 105 and may include a controller or scheduler for controlling communications with UE 115 in cooperation with other base stations 105. For example, the inter-site communication manager 1445 may coordinate the scheduling of transmissions to UE 115 for various interference mitigation techniques, such as beamforming or joint transmission. In some examples, the inter-site communication manager 1445 may provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between base stations 105.

[0210] The code 1435 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1435 may be stored in a non-transitory computer-readable medium, such as a system memory or other type of memory. In some implementations, the code 1435 may not be directly executable by the processor 1440, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0211] Fig.15 1 is a flow chart illustrating a method 1500 for supporting feedback for multicast transmissions according to aspects of the present disclosure. The operations of the method 1500 may be implemented by the UE 115 or a component thereof. For example, the operations of the method 1500 may be implemented by the UE 115 as described with reference to FIG. Figure 7-10In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0212] At 1505, the UE may receive from the base station one or more configurations for the UE to use in providing feedback associated with a multicast transmission from the base station when the UE is in an inactive mode or an idle mode. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be as described with reference to Figure 7-10 Configure the receiver to perform as described.

[0213] At 1510, the UE may monitor a set of time-frequency resources configured for multicast transmission from a base station while the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 Described in the Multicast Monitor.

[0214] At 1515, the UE may transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring when the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 The described feedback transmitter is implemented.

[0215] Fig.16 1 is a flow chart illustrating a method 1600 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 1600 may be implemented by the UE 115 or a component thereof. For example, the operations of the method 1600 may be implemented by the UE 115 or a component thereof. Figure 7-10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0216] At 1605, the UE may receive from the base station one or more configurations for the UE to use in providing feedback associated with a multicast transmission from the base station when the UE is in an inactive mode or an idle mode. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be as described with reference to Figure 7-10 Configure the receiver to perform as described.

[0217] At 1610, the UE may monitor a set of time-frequency resources configured for multicast transmission from a base station while the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 Described in the Multicast Monitor.

[0218] At 1615, the UE may determine a resource pool available for multicast feedback based on the one or more configurations, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using a subset of the time-frequency resources in the resource pool. 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 as described with reference to Figure 7-10 The resource manager described is executed.

[0219] At 1620, the UE may transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring when the UE is in an inactive mode or an idle mode. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be as described with reference to Figure 7-10 The described feedback transmitter is implemented.

[0220] Fig.17 1 is a flow chart illustrating a method 1700 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 1700 may be implemented by the UE 115 or a component thereof. For example, the operations of the method 1700 may be implemented by the UE 115 or a component thereof. Figure 7-10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0221] At 1705, the UE may receive from the base station one or more configurations for the UE to use in providing feedback associated with a multicast transmission from the base station when the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 Configure the receiver to perform as described.

[0222] At 1710, a UE may receive a timing advance command from a base station, the timing advance command indicating a timing advance for use by the UE when in an inactive mode or an idle mode, wherein the timing advance command corresponds to a first set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE. 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 as described with reference to Figure 7-10 The TA receiver described is implemented.

[0223] At 1715, the UE may monitor a set of time-frequency resources configured for multicast transmission from a base station while the UE is in an inactive mode or an idle mode. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed as described with reference to Figure 7-10 Described in the Multicast Monitor.

[0224] At 1720, the UE may transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring when the UE is in an inactive mode or an idle mode. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be as described with reference to Figure 7-10 The described feedback transmitter is implemented.

[0225] Fig.18 1 is a flow chart illustrating a method 1800 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 1800 may be implemented by the UE 115 or a component thereof. For example, the operations of the method 1800 may be implemented by the UE 115 or a component thereof. Figure 7-10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0226] At 1805, the UE may receive from the base station one or more configurations for the UE to use in providing feedback associated with a multicast transmission from the base station when the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 Configure the receiver to perform as described.

[0227] At 1810, a UE may receive a timing advance command from a base station, the timing advance command indicating a timing advance for use by the UE when in an inactive mode or an idle mode, wherein the timing advance command corresponds to a first set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE. 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 as described with reference to Figure 7-10 The TA receiver described is implemented.

[0228] At 1815, the UE may receive a second timing advance command from the base station, the second timing advance command indicating a second timing advance for use by the UE when in an inactive mode or an idle mode, wherein the second timing advance command corresponds to a second set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE. 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 as described with reference to Figure 7-10 The TA receiver described is implemented.

[0229] At 1820, the UE may monitor a set of time-frequency resources configured for multicast transmission from a base station while the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 Described in the Multicast Monitor.

[0230] At 1825, the UE may transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring when the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 The described feedback transmitter is implemented.

[0231] Fig.19 1 is a flow chart illustrating a method 1900 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 1900 may be implemented by the UE 115 or a component thereof. For example, the operations of the method 1900 may be implemented by the UE 115 or a component thereof. Figure 7-10 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0232] At 1905, the UE may receive from the base station one or more configurations for the UE to use in providing feedback associated with a multicast transmission from the base station when the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 Configure the receiver to perform as described.

[0233] At 1910, the UE may determine a set of uplink resources available for use in a reception status report associated with a multicast transmission from a base station. 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 as described with reference to Figure 7-10 The resource manager described is executed.

[0234] At 1915, the UE may monitor a set of time-frequency resources configured for multicast transmission from a base station when the UE is in an inactive mode or an idle mode. 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 as described with reference to Figure 7-10 Described in the Multicast Monitor.

[0235] At 1920, the UE may transmit one or more multicast feedback messages according to the one or more configurations based on the monitoring when the UE is in an inactive mode or an idle mode. The operations of 1920 may be performed according to the methods described herein. In some examples, aspects of the operations of 1920 may be as described with reference to Figure 7-10 The described feedback transmitter is implemented.

[0236] At 1925, the UE may use the uplink resource set to transmit the reception status report. The operations of 1925 may be performed according to the methods described herein. In some examples, various aspects of the operations of 1925 may be performed as described with reference to Figure 7-10 The described status report transmitter is executed.

[0237] Fig. 20 1 is a flow chart illustrating a method 2000 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 2000 may be implemented by the base station 105 or a component thereof. For example, the operations of the method 2000 may be implemented by the base station 105 or a component thereof. Figure 11-14 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0238] At 2005, the base station may transmit to the UE one or more configurations for multicast feedback by the UE in an inactive mode or an idle mode. The operations of 2005 may be performed according to the methods described herein. In some examples, aspects of the operations of 2005 may be performed as described with reference to Figure 11-14 Configure the transmitter as described to execute.

[0239] At 2010, the base station may transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communication. The operations of 2010 may be performed according to the methods described herein. In some examples, aspects of the operations of 2010 may be performed as described with reference to Figure 11-14 The described multicast transmitter is performed.

[0240] At 2015, the base station may monitor for one or more multicast feedback messages from the UE based on transmitting the one or more multicast transmissions according to the one or more configurations. The operations of 2015 may be performed according to the methods described herein. In some examples, aspects of the operations of 2015 may be performed as described with reference to Figure 11-14 The described feedback monitor is implemented.

[0241] Fig.21 2100 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 2100 may be implemented by the base station 105 or a component thereof. For example, the operations of the method 2100 may be implemented by the base station 105 or a component thereof. Figure 11-14 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0242] At 2105, the base station may transmit to the UE one or more configurations for multicast feedback by the UE in an inactive mode or an idle mode. The operations of 2105 may be performed according to the methods described herein. In some examples, aspects of the operations of 2105 may be as described with reference to Figure 11-14 Configure the transmitter as described to execute.

[0243] At 2110, the base station may transmit an indication of a set of RACH resources available for multicast feedback in the one or more configurations. The operations of 2110 may be performed according to the methods described herein. In some examples, aspects of the operations of 2110 may be performed as described with reference to Figure 11-14 The resource launcher described is executed.

[0244] At 2115, the base station may transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communication. The operations of 2115 may be performed according to the methods described herein. In some examples, aspects of the operations of 2115 may be performed as described with reference to Figure 11-14 The described multicast transmitter is performed.

[0245] At 2120, the base station may monitor one or more multicast feedback messages from the UE based on transmitting the one or more multicast transmissions according to the one or more configurations and the RACH resource set. The operations of 2120 may be performed according to the methods described herein. In some examples, aspects of the operations of 2120 may be performed as described with reference to Figure 11-14 The described feedback monitor is implemented.

[0246] Fig. 22 200 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 2200 may be implemented by the base station 105 or a component thereof. For example, the operations of the method 2200 may be implemented by the base station 105 or a component thereof. Figure 11-14 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0247] At 2205, the base station may transmit to the UE one or more configurations for multicast feedback by the UE in an inactive mode or an idle mode. The operations of 2205 may be performed according to the methods described herein. In some examples, aspects of the operations of 2205 may be as described with reference to Figure 11-14 Configure the transmitter as described to execute.

[0248] At 2210, the base station may transmit an indication of a set of RACH preambles available for multicast feedback in the one or more configurations. The operations of 2210 may be performed according to the methods described herein. In some examples, aspects of the operations of 2210 may be as described with reference to Figure 11-14 The resource launcher described is executed.

[0249] At 2215, the base station may transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communication. The operations of 2215 may be performed according to the methods described herein. In some examples, aspects of the operations of 2215 may be performed as described with reference to Figure 11-14 The described multicast transmitter is performed.

[0250] At 2220, the base station may monitor one or more multicast feedback messages from the UE based on transmitting the one or more multicast transmissions according to the one or more configurations and the RACH preamble set. The operations of 2220 may be performed according to the methods described herein. In some examples, aspects of the operations of 2220 may be performed as described with reference to Figure 11-14 The described feedback monitor is implemented.

[0251] Fig.23 2300 for supporting feedback for multicast communications according to aspects of the present disclosure. The operations of the method 2300 may be implemented by the base station 105 or a component thereof. For example, the operations of the method 2300 may be implemented by the base station 105 or a component thereof. Figure 11-14 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0252] At 2305, the base station may transmit to the UE one or more configurations for multicast feedback by the UE in an inactive mode or an idle mode. The operations of 2305 may be performed according to the methods described herein. In some examples, aspects of the operations of 2305 may be as described with reference to Figure 11-14 Configure the transmitter as described to execute.

[0253] At 2310, the base station may transmit an indication of a set of PUCCH resources available for multicast feedback in the one or more configurations. The operations of 2310 may be performed according to the methods described herein. In some examples, aspects of the operations of 2310 may be as described with reference to Figure 11-14 The resource launcher described is executed.

[0254] At 2315, the base station may transmit one or more multicast transmissions via a set of time-frequency resources configured for multicast communication. The operations of 2315 may be performed according to the methods described herein. In some examples, aspects of the operations of 2315 may be performed as described with reference to Figure 11-14 The described multicast transmitter is performed.

[0255] At 2320, the base station may monitor one or more multicast feedback messages from the UE based on transmitting the one or more multicast transmissions according to the one or more configurations and the PUCCH resource set. The operations of 2320 may be performed according to the methods described herein. In some examples, aspects of the operations of 2320 may be performed as described with reference to Figure 11-14 The described feedback monitor is implemented.

[0256] The following provides an overview of various aspects of the disclosure:

[0257] Aspect 1: A method for performing wireless communications at a UE, comprising: receiving one or more configurations from a base station for the UE to use in providing feedback associated with a multicast transmission from the base station when the UE is in an inactive mode or an idle mode; monitoring, by the UE in an inactive mode or an idle mode, a set of time-frequency resources configured for the multicast transmission from the base station; and transmitting, by the UE in an inactive mode or an idle mode, one or more multicast feedback messages according to the one or more configurations based at least in part on the monitoring.

[0258] Aspect 2: The method of Aspect 1 further includes: determining a set of random access channel resources available for multicast feedback based at least in part on the resource allocation indicated by the one or more configurations, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages via the random access channel resource set.

[0259] Aspect 3: The method of any one of Aspects 1 to 2 further includes: determining a set of random access channel preambles available for multicast feedback based at least in part on the resource allocation indicated by the one or more configurations; and selecting a preamble from the set of random access channel preambles, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages via the selected preamble.

[0260] Aspect 4: The method of any one of Aspects 1 to 3 further includes: receiving a multicast message on the time-frequency resource set based at least in part on the monitoring, wherein selecting the preamble code from the random access channel preamble code set includes selecting the preamble code based at least in part on a channel quality metric associated with the received multicast message.

[0261] Aspect 5: The method of any one of Aspects 1 to 4 further includes: receiving a multicast message on the set of time-frequency resources based at least in part on the monitoring; transmitting channel quality information associated with the received multicast message, wherein the channel quality information includes one or more of the following: reference signal received power, beam direction, beam width, geographic location, or altitude and azimuth values ​​associated with one or more beams; and determining time-frequency resources for multicast feedback based at least in part on the channel quality information, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages via the determined time-frequency resources.

[0262] Aspect 6: The method of any one of Aspects 1 to 5 further includes: determining a resource pool available for multicast feedback based at least in part on the one or more configurations, wherein transmitting the one or more multicast feedback messages includes using a subset of time-frequency resources in the resource pool to transmit the one or more multicast feedback messages.

[0263] Aspect 7: The method as in any one of Aspects 1 to 6 further includes: determining a set of physical uplink control channel resources available for multicast feedback based at least in part on the one or more configurations, wherein transmitting the one or more multicast feedback messages includes using a subset of the physical uplink control channel resources to transmit the one or more multicast feedback messages.

[0264] Aspect 8: The method of Aspect 7 further includes: determining an uplink control format for the one or more multicast feedback messages; and filling the payload of the one or more multicast feedback messages based at least in part on a size associated with the uplink control format.

[0265] Aspect 9: The method as in any one of Aspects 1 to 8, further comprising: receiving a timing advance command from the base station, the timing advance command indicating a timing advance for use by the UE when the UE is in the inactive mode or the idle mode, wherein the timing advance command corresponds to a first value set of one or more channel metrics associated with the UE and associated with one or more cellular cells including a serving cellular cell for the UE.

[0266] Aspect 10: The method of Aspect 9 further includes: receiving a second timing advance command from the base station, the second timing advance command indicating a second timing advance for use by the UE when it is in the inactive mode or the idle mode, wherein the second timing advance command corresponds to a second value set of one or more channel metrics associated with the UE and associated with one or more cellular cells including the serving cellular cell for the UE.

[0267] Aspect 11: The method of Aspect 10 further includes: measuring a set of channel metrics of the one or more cellular cells including the serving cellular cell, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using the timing advance at least partially based on the channel metric set satisfying the first value set or using the second timing advance at least partially based on the channel metric set satisfying the second value set.

[0268] Aspect 12: The method of any one of Aspects 10 to 11, wherein the one or more channel metrics include one or more of: reference signal received power, a relative delay between the serving cell and one or more other cells, or a positioning range of the UE.

[0269] Aspect 13: The method as in any one of Aspects 10 to 12, further comprising: receiving one or more of the timing advance command or the second timing advance command in the one or more configurations, the one or more configurations indicating an uplink resource set for multicast feedback, wherein transmitting the one or more multicast feedback messages includes using the uplink resource set to transmit the one or more multicast feedback messages.

[0270] Aspect 14: The method of any one of Aspects 9 to 13, further comprising: receiving a neural network parameter set in the timing advance command from the base station, wherein the neural network parameter set indicates the timing advance.

[0271] Aspect 15: The method of any one of Aspects 1 to 14, further comprising: receiving a neural network model and a neural network parameter set from the base station at the UE when in a connected mode, the neural network model and the neural network parameter set being associated with a neural network for a timing advance; receiving one or more neural network parameters from the base station; and determining the timing advance based at least in part on the neural network model, the neural network parameter set, and the one or more neural network parameters, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages by the UE when in the inactive mode or the idle mode based at least in part on the timing advance.

[0272] Aspect 16: The method as in any one of Aspects 1 to 15, further comprising: determining an uplink resource set available for use in a reception status report associated with a multicast transmission from the base station, wherein the uplink resource set comprises random access channel resources or uplink control channel resources; and using the uplink resource set to transmit the reception status report.

[0273] Aspect 17: The method of Aspect 16 further includes: monitoring multiple opportunities to look for multicast transmissions from the base station; receiving multiple physical control channels for multicast transmissions based at least in part on monitoring the multiple opportunities; transmitting an indication of the number of the multiple physical control channels received for multicast transmissions in the reception status report; and transmitting in the reception status report a ratio between the number of the multiple physical control channels received for multicast transmissions and the total amount of physical control channels for multicast transmissions scheduled on the multiple opportunities, wherein the total amount of physical control channels for multicast transmissions corresponds to an uplink control channel resource set.

[0274] Aspect 18: The method of any one of Aspects 1 to 17 further includes: receiving a broadcast message from the base station, the broadcast message indicating a counting duration for a service for multicast transmission supported by the base station; and transmitting a service request message requesting the service for the multicast transmission supported by the base station within the counting duration based at least in part on an identifier of the UE.

[0275] Aspect 19: The method of aspect 18 further comprises: receiving a probability indicator for the UE from the base station, wherein transmitting the service request message comprises transmitting the message according to the probability indicator.

[0276] Aspect 20: A method for performing wireless communications at a base station, comprising: transmitting to a UE one or more configurations for multicast feedback by the UE when the UE is in an inactive mode or an idle mode, transmitting one or more multicast transmissions via a set of time-frequency resources configured for multicast communication, and monitoring one or more multicast feedback messages from the UE based at least in part on transmitting the one or more multicast transmissions according to the one or more configurations.

[0277] Aspect 21: The method of Aspect 20 further comprises: transmitting an indication of a set of random access channel resources available for multicast feedback in the one or more configurations; and monitoring the set of random access channel resources to find the one or more multicast feedback messages.

[0278] Aspect 22: A method as in any one of Aspects 20 to 21, further comprising: transmitting an indication of a set of random access channel preambles available for multicast feedback in the one or more configurations; and monitoring based at least in part on the random access channel preamble set to search for the one or more multicast feedback messages.

[0279] Aspect 23: The method of any one of Aspects 20 to 22 further includes: receiving channel quality information associated with a multicast channel used for multicast communication with the UE from the UE, wherein the channel quality information includes one or more of the following: reference signal received power, beam direction, beam width, geographic location, or altitude and azimuth values ​​associated with one or more beams; determining a resource pool for multicast feedback for the UE based at least in part on the channel quality information; and transmitting an indication of the resource pool in the one or more configurations.

[0280] Aspect 24: The method of Aspect 23, further comprising: receiving the one or more multicast feedback messages via a subset of the time-frequency resources in the resource pool based at least in part on the monitoring.

[0281] Aspect 25: The method of any one of Aspects 20 to 24, further comprising: transmitting an indication of a set of physical uplink control channel resources available for multicast feedback in the one or more configurations; and monitoring the set of physical uplink control channel resources to search for the one or more multicast feedback messages.

[0282] Aspect 26: The method of any one of Aspects 20 to 25 further includes: transmitting a timing advance command to the UE, the timing advance command indicating a timing advance for use by the UE when it is in the inactive mode or the idle mode, wherein the timing advance command corresponds to a first value set of one or more channel metrics associated with the UE and associated with one or more cellular cells including a serving cellular cell for the UE.

[0283] Aspect 27: The method as in Aspect 26 further includes: transmitting a second timing advance command to the UE, the second timing advance command indicating a second timing advance for use by the UE when it is in the inactive mode or the idle mode, wherein the second timing advance command corresponds to a second value set of one or more channel metrics associated with the UE and associated with one or more cellular cells including the serving cellular cell for the UE.

[0284] Aspect 28: The method of Aspect 27 further includes: receiving the one or more multicast feedback messages based at least in part on the monitoring, at least in part on the channel measurement set at the UE satisfying the first value set according to the timing advance, or at least in part on the channel measurement set at the UE satisfying the second value set according to the second timing advance.

[0285] Aspect 29: An apparatus for wireless communication at a UE, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method as described in any one of Aspects 1 to 19.

[0286] Aspect 30: An apparatus for wireless communication at a UE, comprising at least one means for performing the method of any one of aspects 1 to 19.

[0287] Aspect 31: A non-transitory computer-readable medium storing code for wireless communication at a UE, the code comprising instructions executable by a processor to perform the method of any one of aspects 1 to 19.

[0288] Aspect 32: An apparatus for wireless communication at a base station, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method as in any one of aspects 20 to 28.

[0289] Aspect 33: An apparatus for wireless communication at a base station, comprising at least one means for performing the method of any one of aspects 20 to 28.

[0290] Aspect 34: A non-transitory computer-readable medium storing code for wireless communication at a base station, the code comprising instructions executable by a processor to perform the method of any one of aspects 20 to 28.

[0291] It should be noted that the methods described herein describe possible implementations, and that the various operations and steps may be rearranged or otherwise modified and other implementations are possible. Furthermore, aspects from two or more methods may be combined.

[0292] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applied to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0293] The information and signals described herein may be represented using any of a variety of different techniques and technologies. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referred to throughout this description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0294] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a central processing unit (CPU), 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 herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0295] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Other examples and implementations fall within the scope of the present disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features that implement the functions may also be physically located in different locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0296] Computer-readable medium includes both non-transient computer storage medium and communication medium, and it includes any medium that facilitates computer program to transfer from one place to another place.Non-transient storage medium can be any available medium that can be accessed by general or special-purpose computer.As an example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disk (CD) ROM or other optical disk storage, disk storage or other magnetic storage device, or can be used to carry or store instruction or data structure form of desired program code means and can be accessed by general or special-purpose computer, or general or special-purpose processor any other non-transient medium.Any connection is also properly referred to as computer-readable medium.For example, if software is transmitted from website, server or other remote source using coaxial cable, optical fiber cable, twisted pair, digital subscriber line (DSL) or wireless technology such as infrared, radio and microwave, then this coaxial cable, optical fiber cable, twisted pair, DSL or wireless technology such as infrared, radio and microwave are just included in the definition of computer-readable medium. Disk and disc as used herein include CDs, laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

[0297] As used herein (including in the claims), "or" used in a list of items (e.g., a list of items with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (in other words, A and B and C). Similarly, as used herein, the phrase "based on" should not be interpreted as referring to a closed set of conditions. For example, an example step described as "based on condition A" may be based on both condition A and condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0298] In the accompanying drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes between similar components. If only the first reference number is used in the specification, the description may apply to any of the similar components having the same first reference number regardless of the second reference number, or other subsequent reference numbers.

[0299] The descriptions set forth herein in conjunction with the accompanying drawings describe example configurations and do not represent all examples that can be implemented or fall within the scope of the claims. The term "example" as used herein means "used as an example, instance, or illustration" and does not mean "better than" or "better than other examples." This detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0300] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to one of ordinary skill in the art, and the universal principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be granted the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for wireless communication at a user equipment (UE), comprising: receiving, from a network node, one or more configurations for use by the UE, while in an inactive mode or an idle mode, to provide feedback associated with a multicast transmission from the network node; monitoring a set of time-frequency resources configured for the multicast transmission from the network node while in the inactive mode or the idle mode; transmitting one or more multicast feedback messages according to the one or more configurations based at least in part on the monitoring while in the inactive mode or the idle mode; as well as A reception status report is transmitted indicating a ratio between a number of received physical control channels for the multicast transmission and a total amount of physical control channels for the multicast transmission scheduled on a set of monitoring opportunities, the reception status report being transmitted on a set of uplink resources associated with the ratio.

2. The method of claim 1, further comprising: A set of random access channel resources available for multicast feedback is determined based at least in part on the resource allocation indicated by the one or more configurations, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages via the set of random access channel resources.

3. The method of claim 1, further comprising: determining a set of random access channel preambles available for multicast feedback based at least in part on the resource allocation indicated by the one or more configurations; as well as A preamble from the set of random access channel preambles is selected, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using the selected preamble.

4. The method of claim 3, further comprising: A multicast message is received on the set of time-frequency resources based at least in part on the monitoring, wherein selecting the preamble from the set of random access channel preambles comprises selecting the preamble based at least in part on a channel quality metric associated with the received multicast message.

5. The method of claim 1, further comprising: receiving a multicast message on the set of time-frequency resources based at least in part on the monitoring; transmitting channel quality information associated with the received multicast message, wherein the channel quality information comprises one or more of: a reference signal received power, a beam direction, a beam width, a geographic location, or an altitude and azimuth value associated with one or more beams; and Time-frequency resources for multicast feedback are determined based at least in part on the channel quality information, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages via the determined time-frequency resources.

6. The method of claim 1, further comprising: A resource pool available for multicast feedback is determined based at least in part on the one or more configurations, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using a subset of time-frequency resources in the resource pool.

7. The method of claim 1, further comprising: A set of physical uplink control channel resources available for multicast feedback is determined based at least in part on the one or more configurations, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages using a subset of the physical uplink control channel resources.

8. The method of claim 7, further comprising: determining an uplink control format for the one or more multicast feedback messages; as well as A payload of the one or more multicast feedback messages is populated based at least in part on a size associated with the uplink control format.

9. The method of claim 1, further comprising: Receiving a timing advance command from the network node, the timing advance command indicating a timing advance for use by the UE when in the inactive mode or the idle mode, wherein the timing advance command corresponds to a first set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE.

10. The method of claim 9, further comprising: receiving a second timing advance command from the network node, the second timing advance command indicating a second timing advance for use by the UE when in the inactive mode or the idle mode, wherein the second timing advance command corresponds to a second set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including the serving cell for the UE.

11. The method of claim 10, further comprising: measuring a set of channel metrics of the one or more cellular cells including the serving cellular cell, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using the timing advance based at least in part on the set of channel metrics satisfying the first set of values ​​or using the second timing advance based at least in part on the set of channel metrics satisfying the second set of values.

12. The method of claim 10, wherein: The one or more channel metrics include one or more of: reference signal received power, a relative delay between the serving cell and one or more other cells, or a positioning range of the UE.

13. The method of claim 10, further comprising: One or more of the timing advance command or the second timing advance command is received in the one or more configurations, the one or more configurations indicating a set of uplink resources for multicast feedback, wherein transmitting the one or more multicast feedback messages includes transmitting the one or more multicast feedback messages using the set of uplink resources.

14. The method of claim 9, further comprising: A set of neural network parameters is received in the timing advance command from the network node, wherein the set of neural network parameters indicates the timing advance.

15. The method of claim 1, further comprising: receiving a neural network model and a set of neural network parameters from the network node while in a connected mode, the neural network model and the set of neural network parameters being associated with a neural network for timing advance; receiving one or more neural network parameters from the network node; as well as The timing advance is determined based at least in part on the neural network model, the set of neural network parameters, and the one or more neural network parameters, wherein transmitting the one or more multicast feedback messages comprises transmitting the one or more multicast feedback messages based at least in part on the timing advance while in the inactive mode or the idle mode.

16. The method of claim 1, further comprising: The set of uplink resources available for use for the reception status report associated with the multicast transmission from the network node is determined, wherein the set of uplink resources comprises random access channel resources or uplink control channel resources.

17. The method of claim 16, further comprising: monitoring a plurality of opportunities for the multicast transmission from the network node; receiving a plurality of physical control channels for a multicast transmission based at least in part on monitoring the plurality of opportunities; An indication of a number of the plurality of physical control channels for multicast transmission received is transmitted in the reception status report, wherein the total amount of physical control channels for multicast transmission corresponds to a set of uplink control channel resources.

18. The method of claim 1, further comprising: receiving a broadcast message from the network node, the broadcast message indicating a count duration for a service of a multicast transmission supported by the network node; as well as A service request message is transmitted within the counting duration requesting a service for the multicast transmission supported by the network node based at least in part on the identifier of the UE.

19. The method of claim 18, further comprising: A probability indicator for the UE is received from the network node, wherein transmitting the service request message comprises transmitting the message according to the probability indicator.

20. A method for wireless communication at a network node, comprising: transmitting one or more configurations for multicast feedback for use by a user equipment (UE) when in an inactive mode or an idle mode; transmitting one or more multicast transmissions via a set of time-frequency resources configured for multicast communication; monitoring for one or more multicast feedback messages from the UE based at least in part on transmitting the one or more multicast transmissions in accordance with the one or more configurations; as well as A reception status report is received indicating a ratio between a number of physical control channels received by the UE for the multicast transmission and a total amount of physical control channels scheduled on a set of monitoring opportunities for the multicast transmission, the reception status report being received on a set of uplink resources associated with the ratio.

21. The method of claim 20, further comprising: transmitting, in the one or more configurations, an indication of a set of random access channel resources available for multicast feedback; as well as The set of random access channel resources is monitored for the one or more multicast feedback messages.

22. The method of claim 20, further comprising: transmitting, in the one or more configurations, an indication of a set of random access channel preambles available for multicast feedback; as well as Monitoring for the one or more multicast feedback messages is performed based at least in part on the set of random access channel preambles.

23. The method of claim 20, further comprising: receiving channel quality information associated with a multicast channel used for multicast communications with the UE, wherein the channel quality information comprises one or more of: a reference signal received power, a beam direction, a beam width, a geographic location, or altitude and azimuth values ​​associated with one or more beams; determining a resource pool for multicast feedback to the UE based at least in part on the channel quality information; and An indication of the resource pool is transmitted in the one or more configurations.

24. The method of claim 23, further comprising: The one or more multicast feedback messages are received via a subset of time-frequency resources in the resource pool based at least in part on the monitoring.

25. The method of claim 20, further comprising: transmitting, in the one or more configurations, an indication of a set of physical uplink control channel resources available for multicast feedback; as well as The set of physical uplink control channel resources is monitored for the one or more multicast feedback messages.

26. The method of claim 20, further comprising: transmitting a timing advance command indicating a timing advance for use by the UE when in the inactive mode or the idle mode, wherein the timing advance command corresponds to a first set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including a serving cell for the UE.

27. The method of claim 26, further comprising: transmitting a second timing advance command indicating a second timing advance for use by the UE when in the inactive mode or the idle mode, wherein the second timing advance command corresponds to a second set of values ​​of one or more channel metrics associated with the UE and associated with one or more cells including the serving cell for the UE.

28. The method of claim 27, further comprising: The one or more multicast feedback messages are received based at least in part on the monitoring, based at least in part on a set of channel metrics at the UE satisfying the first set of values ​​according to the timing advance, or based at least in part on a set of channel metrics at the UE satisfying the second set of values ​​according to the second timing advance.

29. An apparatus for wireless communication at a user equipment (UE), comprising: means for receiving from a network node one or more configurations for use by the UE, while in an inactive mode or an idle mode, in providing feedback associated with a multicast transmission from the network node; means for monitoring a set of time-frequency resources configured for said multicast transmission from said network node while in said inactive mode or said idle mode; means for transmitting one or more multicast feedback messages in accordance with the one or more configurations based at least in part on the monitoring while in the inactive mode or the idle mode; as well as Means for transmitting a reception status report indicating a ratio between a number of received physical control channels for the multicast transmission and a total amount of physical control channels for the multicast transmission scheduled on a set of monitoring opportunities, the reception status report being transmitted on a set of uplink resources associated with the ratio.

30. An apparatus for wireless communication at a network node, comprising: means for transmitting one or more configurations for multicast feedback by a user equipment (UE) in an inactive mode or an idle mode; means for transmitting one or more multicast transmissions via a set of time-frequency resources configured for multicast communications; means for monitoring one or more multicast feedback messages from the UE based at least in part on transmitting the one or more multicast transmissions in accordance with the one or more configurations; as well as Means for receiving a reception status report indicating a ratio between a number of physical control channels received by the UE for the multicast transmission and a total amount of physical control channels scheduled on a set of monitoring opportunities for the multicast transmission, the reception status report being received on a set of uplink resources associated with the ratio.

31. An apparatus for wireless communication at a user equipment (UE), comprising: processor; a memory coupled to the processor; as well as Instructions stored in the processor and executable by the processor to cause the device to: receiving, from a network node, one or more configurations for use by the UE, while in an inactive mode or an idle mode, to provide feedback associated with a multicast transmission from the network node; monitoring a set of time-frequency resources configured for the multicast transmission from the network node while in the inactive mode or the idle mode; transmitting one or more multicast feedback messages according to the one or more configurations based at least in part on the monitoring while in the inactive mode or the idle mode; as well as A reception status report is transmitted indicating a ratio between a number of received physical control channels for the multicast transmission and a total amount of physical control channels for the multicast transmission scheduled on a set of monitoring opportunities, the reception status report being transmitted on a set of uplink resources associated with the ratio.

32. An apparatus for wireless communication at a network node, comprising: processor; a memory coupled to the processor; as well as Instructions stored in the processor and executable by the processor to cause the device to: transmitting one or more configurations for multicast feedback by a user equipment (UE) in an inactive mode or an idle mode; transmitting one or more multicast transmissions via a set of time-frequency resources configured for multicast communication; monitoring one or more multicast feedback messages from the UE based at least in part on transmitting the one or more multicast transmissions in accordance with the one or more configurations; as well as A reception status report is received indicating a ratio between a number of physical control channels received by the UE for the multicast transmission and a total amount of physical control channels scheduled on a set of monitoring opportunities for the multicast transmission, the reception status report being received on a set of uplink resources associated with the ratio.

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