Apparatus for wireless communication and method for managing multicast and broadcast service (MBS) reception feedback

Abstract

The present disclosure relates to an apparatus and method for providing and managing reception feedback for a multicast and broadcast service (MBS). A base station (BS) may select configuration parameters for MBS communications, such as an indication of an MBS retransmission process for an MBS service, and transmit the same to a group of user equipment devices (UEs). The BS may also send an MBS data communication to the group of UEs. A first UE may receive the MBS data communication, but may determine that the received MBS data communication is corrupted. The first UE may respond by sending a negative acknowledgement (NACK) message to the BS. Based on the configuration parameters, the BS may retransmit the MBS data communication as an MBS transmission or as a unicast transmission. Based on the configuration parameters, the first UE may monitor appropriate resources to receive the retransmitted MBS data communication.

Description

Technical Field

[0001] The present application relates to wireless communications, and more particularly, to systems, apparatuses, and methods for improving the reliability of multicast and broadband service (MBS) communications by receiving feedback.

[0002] Related technical description

[0003] The use of wireless communication systems is growing rapidly. In recent years, wireless devices such as smartphones and tablet computers have become increasingly sophisticated. In addition to supporting phone calls, many mobile devices (i.e., user equipment devices or UEs) now also provide access to the Internet, email, text messaging and navigation using the Global Positioning System (GPS), and are capable of operating sophisticated applications that utilize these capabilities. In addition, there are many different wireless communication technologies and wireless communication standards. Some examples of wireless communication standards include GSM, UMTS (e.g., associated with WCDMA or TD-SCDMA air interfaces), LTE, Advanced LTE (LTE-A), NR, HSPA, 3GPP2 CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), IEEE 802.11 (WLAN or Wi-Fi), BLUETOOTH TM wait.

[0004] One aspect of cellular communication systems relates to multicast and broadband service (MBS) communications.Improvements in the art are desired. Summary of the Invention

[0005] Embodiments of apparatuses, systems, and methods are provided herein for reducing delay in high propagation delay wireless communication systems by using receive feedback.

[0006] An apparatus is disclosed, comprising a processor configured to cause a base station to select a retransmission process for a multicast and broadcast service (MBS) service from a plurality of available retransmission processes. The base station may send an indication of the selected retransmission process and MBS data communications for the MBS service to a plurality of UEs. The base station may receive a negative acknowledgement (NACK) message in response to the MBS data communications from a first UE among the plurality of UEs, and may respond to the received NACK message based on the selected retransmission process. When the selected retransmission process is a first process, responding to the received NACK message may include retransmitting the MBS data transmission using resources allocated for the MBS service. When the selected retransmission process is a second process, responding to the received NACK message may include retransmitting the MBS data communications using resources allocated for unicast transmission to the first UE.

[0007] In some scenarios, responding to the received NACK message may include not retransmitting the MBS data communication when the selected retransmission procedure is the third procedure.

[0008] In some scenarios, the NACK message may be received via a physical uplink control channel (PUCCH) resource allocated for MBS service. In some such scenarios, the base station may receive an additional NACK message from a second UE among the multiple UEs, where the additional NACK message is received via the same PUCCH resource allocated for MBS service. In some such scenarios, the PUCCH resource may be allocated for MBS reception feedback by a subgroup of the multiple UEs, where the first UE is included in the subgroup.

[0009] In some scenarios, the NACK message may be sent using a PUCCH resource allocated to the first UE for reception feedback of an MBS message received by the first UE.

[0010] In some scenarios, the NACK message may be sent using a PUCCH resource allocated to the first UE for reception feedback of a unicast message received by the first UE.

[0011] In some scenarios, the NACK message may be sent using the unicast Physical Uplink Shared Channel (PUSCH).

[0012] In some scenarios, the base station may receive, from the UE, reception statistics regarding messages associated with the MBS service received by the UE.

[0013] In some scenarios, an indication of the selected retransmission process may be sent in a downlink control indicator (DCI) for MBS data scheduling.

[0014] In some scenarios, the indication of the selected retransmission procedure may be sent in a Medium Access Control (MAC) Control Element (CE).

[0015] An apparatus is disclosed that includes a processor configured to cause a user equipment (UE) to receive, from a base station, an indication of a multicast and broadcast service (MBS) retransmission procedure for a MBS service. The UE may also receive an MBS data transmission from the base station and, in response to determining that reception of the MBS data transmission is corrupted, may send a negative acknowledgement (NACK) message to the base station. The UE may monitor retransmissions of the MBS data transmission in response to the NACK message. When the indication of the MBS retransmission procedure has a first value, monitoring the retransmissions may include monitoring resources allocated for MBS communications. When the indication of the MBS retransmission procedure has a second value, monitoring the retransmissions may include monitoring resources allocated for unicast communications to the UE.

[0016] In some scenarios, an indication of the MBS retransmission process may be received in a downlink control indicator (DCI) for a single cell-multicast traffic channel (SC-MTCH).

[0017] In some scenarios, the indication of the MBS retransmission process is received in a Medium Access Control (MAC) Control Element (CE).

[0018] In some scenarios, the UE may not send an acknowledgement (ACK) message in response to determining that the MBS data transmission was correctly received.

[0019] In some scenarios, the NACK message may be sent using ACK / NACK physical uplink control channel (PUCCH) resources allocated for MBS services. In some such scenarios, ACK / NACK PUCCH resources may be allocated for MBS reception feedback by a subset of a group of UEs subscribed to the MBS service, where the UE is included in the group of UEs.

[0020] In some scenarios, the NACK message may be sent using ACK / NACK PUCCH resources allocated for reception feedback for MBS messages received by the UE.

[0021] In some scenarios, the NACK message may be sent using an ACK / NACK PUCCH resource configured for reception feedback for unicast messages received by the UE.

[0022] In some scenarios, the NACK message may be sent using the unicast physical uplink shared channel (PUSCH). In some such scenarios, sending the NACK message using the unicast PUSCH may be in response to determining that sending the NACK message on the ACK / NACK PUCCH resources will collide in time with the unicast PUSCH.

[0023] In some scenarios, the UE may receive an indication that MBS reception feedback is enabled for the MBS service, wherein sending the NACK message is in response to receiving the indication that MBS reception feedback is enabled.

[0024] Systems and methods having features similar to those outlined above are also disclosed.

[0025] It should be noted that the techniques described herein may be implemented in and / or used with several different types of devices, including but not limited to base stations, access points, mobile phones, portable media players, tablet computers, wearable devices, unmanned aerial vehicles, unmanned flight controllers, automobiles and / or motor vehicles, and various other computing devices.

[0026] This summary is intended to provide a brief overview of some of the subject matter described in this document. Therefore, it should be understood that the above-described features are merely examples and should not be construed as narrowing the scope or spirit of the subject matter described herein in any way. Other features, aspects, and advantages of the subject matter described herein will become apparent from the following detailed description, accompanying drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] A better understanding of the present subject matter may be obtained when the following detailed description of various embodiments is considered in conjunction with the following drawings, in which:

[0028] Figure 1 An exemplary (and simplified) wireless communication system is shown in accordance with some embodiments.

[0029] Figure 2 An exemplary base station in communication with an exemplary wireless user equipment (UE) device is shown in accordance with some embodiments.

[0030] Figure 3 An exemplary block diagram of a UE according to some embodiments is illustrated.

[0031] Figure 4 An exemplary block diagram of a base station according to some embodiments is shown.

[0032] Figure 5 A flow chart illustrating an exemplary method for managing MBS reception feedback by a base station according to some embodiments is shown.

[0033] Figure 6 A flow chart illustrating an exemplary method for providing MBS reception feedback by a UE according to some embodiments is shown.

[0034] While the features described herein are susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the drawings and detailed description thereof are not intended to limit this disclosure to the specific forms disclosed, but on the contrary, are intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the appended claims. DETAILED DESCRIPTION

[0035] Acronyms

[0036] Various acronyms are used throughout this disclosure. The definitions of the most prominent acronyms used that may appear throughout this disclosure are as follows:

[0037] BS: Base Station

[0038] CE: Control Element

[0039] DCI: Downlink Control Information

[0040] DL: Downlink

[0041] GSM: Global System for Mobile Communications

[0042] HARQ: Hybrid Automatic Repeat Request

[0043] IE: Information Element

[0044] LTE: Long Term Evolution

[0045] MAC: Media Access Control

[0046] MBS: Multicast and Broadcast Service

[0047] MCH: Multicast channel

[0048] NR: New Radio

[0049] PDSCH: Physical Downlink Shared Channel

[0050] PRACH: Physical Random Access Channel

[0051] PUCCH: Physical Uplink Control Channel

[0052] PUSCH: Physical Uplink Shared Channel

[0053] PTM: Point-to-Multipoint

[0054] PTP: peer-to-peer

[0055] RACH: Random Access Channel

[0056] RAT: Radio Access Technology

[0057] RF: Radio Frequency

[0058] RX: Receive

[0059] SC-MCCH: Single Cell Multicast Control Channel SC-MTCH: Single Cell Multicast Traffic Channel TX: Transmit

[0060] UE: User Equipment

[0061] UL: Uplink

[0062] UMTS: Universal Mobile Telecommunications System

[0063] the term

[0064] The following is a glossary of terms that will appear in this disclosure:

[0065] Memory medium—any of various types of non-transitory memory devices or storage devices. The term "memory medium" is intended to include installation media, such as CD-ROMs, floppy disks, or tape devices; computer system memory or random access memory such as DRAM, DDR RAM, SRAM, EDO RAM, Rambus RAM, etc.; non-volatile memory such as flash memory, magnetic media, for example, hard drives or optical storage devices; registers or other similar types of memory elements, etc. The memory medium may also include other types of non-transitory memory or a combination thereof. In addition, the memory medium may be located in the first computer system executing the program, or may be located in a different second computer system connected to the first computer system via a network such as the Internet. In the latter example, the second computer system may provide program instructions to the first computer system for execution. The term "memory medium" may include two or more memory media that may reside in different locations in different computer systems connected, for example, via a network. The memory medium may store program instructions (e.g., represented as a computer program) that may be executed by one or more processors.

[0066] Carrier Media—storage media as described above, and physical transmission media such as a bus, network, and / or other physical transmission media that carry signals such as electrical, electromagnetic, or digital signals.

[0067] Computer system (or computer)—any of various types of computing or processing systems, including a personal computer system (PC), a mainframe computer system, a workstation, a network appliance, an Internet appliance, a personal digital assistant (PDA), a television system, a grid computing system, or other devices or combinations of devices. In general, the term "computer system" can be broadly defined as any device (or combination of devices) that includes at least one processor that executes instructions from a memory medium.

[0068] User Equipment (UE) (or "UE device") - any of various types of computer systems or devices that are mobile or portable and that perform wireless communication. Examples of UE devices include mobile phones or smartphones (e.g., iPhones, TM , based on Android TM phones), tablet computers (e.g., iPadTM 、Samsung Galaxy TM ), portable gaming devices (e.g., Nintendo DS TM PlayStation Portable TM 、Gameboy Advance TM , iPhone TM ), wearable devices (e.g., smart watches, smart glasses), laptops, PDAs, portable Internet devices, music players, data storage devices, other handheld devices, cars and / or motor vehicles, unmanned aerial vehicles (UAVs) (e.g., drones), UAV controllers (UACs), etc. In general, the term "UE" or "UE device" can be broadly defined to cover any electronic device, computing device, and / or telecommunication device (or combination of these devices) that is easily transportable by a user and capable of wireless communication.

[0069] Wireless Device—Any of various types of computer systems or devices that perform wireless communications. A wireless device may be portable (or mobile), or may be stationary or fixed in place. A UE is an example of a wireless device.

[0070] Communication Device—Any of various types of computer systems or devices that perform communication, where the communication may be wired or wireless. A communication device may be portable (or mobile), or may be stationary or fixed in place. A wireless device is one example of a communication device. A UE is another example of a communication device.

[0071] Base Station (BS)—The term “base station” has the full breadth of its ordinary meaning and includes at least a wireless communication station installed at a fixed location and used to communicate as part of a wireless telephone system or radio system.

[0072] Processing element (or processor) – refers to any element or combination of elements capable of performing functions in a device, such as a user equipment device or a cellular network device. A processing element may include, for example, a processor and associated memory, portions or circuits of individual processor cores, entire processor cores, processor arrays, circuits such as ASICs (application-specific integrated circuits), programmable hardware elements such as field-programmable gate arrays (FPGAs), and any combination thereof.

[0073] Wi-Fi—The term "Wi-Fi" has the full scope of its ordinary meaning and includes at least wireless communication networks, or RATs, that are served by wireless LAN (WLAN) access points and provide connectivity to the Internet through those access points. Most modern Wi-Fi networks (or WLAN networks) are based on the IEEE 802.11 standard and are marketed under the name "Wi-Fi." Wi-Fi (WLAN) networks are distinct from cellular networks.

[0074] Automatic—refers to an action or operation being performed by a computer system (e.g., software executed by the computer system) or a device (e.g., a circuit, a programmable hardware element, an ASIC, etc.) without requiring user input to directly specify or execute the action or operation. Thus, the term "automatically" is in contrast to an action being manually performed or specified by a user, where the user provides input to directly perform the action. An automatic process may be initiated by user-provided input, but the subsequent actions performed "automatically" are not specified by the user, i.e., they are not performed "manually," where the user specifies each action to be performed. For example, a user filling out an electronic form by selecting each field and providing input specifying information (e.g., by typing information, selecting checkboxes, radio selections, etc.) is not manually filling out the form, even though the computer system must update the form in response to the user's actions. The form can be automatically filled out by a computer system, where the computer system (e.g., software executing on the computer system) analyzes the fields of the form and fills it out without requiring any user input to specify the answers to the fields. As indicated above, a user can invoke the automatic filling of a form without participating in the actual filling out of the form (e.g., the user does not manually specify the answers to the fields; they are automatically completed). This specification provides various examples of operations that are automatically performed in response to actions that a user has taken.

[0075] Configured to—Various components may be described as being “configured to” perform one or more tasks. In such contexts, “configured to” is a broad statement that generally means “having the structure” to perform one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently performing the task (e.g., a set of electrical conductors can be configured to electrically connect a module to another module even when the two modules are not connected). In some contexts, “configured to” can be a broad statement that generally means “having the circuitry” to perform one or more tasks during operation. Thus, a component can be configured to perform a task even when the component is not currently turned on. Generally, the circuitry that forms the structure corresponding to “configured to” may include hardware circuitry.

[0076] For ease of description, various components may be described as performing one or more tasks. Such descriptions should be interpreted as including the phrase "configured to." Representing a component as being configured to perform one or more tasks expressly does not invoke the sixth paragraph of section 112 of title 35 of the United States Code for that component.

[0077] Figure 1 and Figure 2 -Exemplary Communication System

[0078] Figure 1 An exemplary (and simplified) wireless communication system is shown in which various aspects of the present disclosure may be implemented according to some embodiments. Figure 1 The system is only one example of a possible system, and the embodiment may be implemented in any of a variety of systems as desired.

[0079] As shown, the exemplary wireless communication system includes a base station 102 that communicates with one or more (e.g., any number) user devices 106A, 106B, and so on through 106N via a transmission medium. Each user device may be referred to herein as a "user equipment" (UE) or a UE device. Accordingly, user device 106 is referred to as a UE or a UE device.

[0080] Base station 102 may be a base transceiver station (BTS) or a cell site and may include hardware and / or software that enables wireless communications with UEs 106A to 106N. If base station 102 is implemented in the context of LTE, it may be referred to as an "eNodeB" or "eNB." If base station 102 is implemented in the context of 5G NR, it may alternatively be referred to as a "gNodeB" or "gNB." Base station 102 may also be equipped to communicate with network 100 (e.g., a cellular service provider's core network, a telecommunications network such as the Public Switched Telephone Network (PSTN), and / or the Internet, among various other possible networks). Thus, base station 102 may facilitate communications between user devices and / or between user devices and network 100. The communication area (or coverage area) of a base station may be referred to as a "cell." Also as used herein, with respect to a UE, a base station may sometimes be considered to represent the network, taking into account the UE's uplink and downlink communications. Thus, a UE communicating with one or more base stations in a network may also be understood as a UE communicating with the network.

[0081] The base station 102 and the user equipment may be configured to communicate over a transmission medium using any of a variety of radio access technologies (RATs), also known as wireless communication technologies or telecommunication standards, such as GSM, UMTS (WCDMA), LTE, Advanced LTE (LTE-A), LAA / LTE-U, 5G NR, 3GPP2, CDMA2000 (e.g., 1xRTT, 1xEV-DO, HRPD, eHRPD), Wi-Fi, and the like.

[0082] Base station 102 and other similar base stations operating according to the same or different cellular communication standards may thus be provided as one or more cell networks that may provide continuous or nearly continuous overlapping service to UE 106 and similar devices over a geographic area via one or more cellular communication standards.

[0083] Note that the UE 106 is capable of communicating using multiple wireless communication standards. For example, the UE 106 may be configured to communicate using either or both of the 3GPP cellular communication standard or the 3GPP2 cellular communication standard. In some embodiments, the UE 106 may be configured to perform techniques for reducing latency in a multi-beam wireless communication system, such as according to the various methods described herein. The UE 106 may also or alternatively be configured to communicate using WLAN, BLUETOOTH, or other similar communication technologies. TM , one or more global navigation satellite systems (GNSS, such as GPS or GLONASS), one and / or more mobile television broadcast standards (e.g., ATSC-M / H), etc. Other combinations of wireless communication standards (including more than two wireless communication standards) are also possible.

[0084] Figure 2An exemplary user equipment 106 (e.g., one of devices 106A to 106N) in communication with a base station 102 according to some embodiments is shown. UE 106 can be a device with wireless network connectivity, such as a mobile phone, a handheld device, a wearable device, a computer or tablet computer, an unmanned aerial vehicle (UAV), an unmanned flight controller (UAC), a car, or virtually any type of wireless device. UE 106 may include a processor (processing element) configured to execute program instructions stored in a memory. UE 106 can execute any of the method embodiments described in the present invention by executing such stored instructions. Alternatively or in addition, UE 106 may include a programmable hardware element, such as an FPGA (field programmable gate array), an integrated circuit, and / or any of various other possible hardware components configured to execute (e.g., individually or in combination) any one of the method embodiments described herein or any part of any one of the method embodiments described herein. UE 106 can be configured to communicate using any one of a plurality of wireless communication protocols. For example, UE 106 may be configured to communicate using two or more of CDMA2000, LTE, LTE-A, 5G NR, WLAN, or GNSS. Other combinations of wireless communication standards are also possible.

[0085] UE 106 may include one or more antennas for communicating using one or more wireless communication protocols according to one or more RAT standards. In some embodiments, UE 106 may share one or more portions of a receive chain and / or transmit chain between multiple wireless communication standards. The shared radio components may include a single antenna, or may include multiple antennas for performing wireless communication (e.g., for MIMO). Typically, the radio components may include any combination of a baseband processor, analog radio frequency (RF) signal processing circuits (e.g., including filters, mixers, oscillators, amplifiers, etc.), or digital processing circuits (e.g., for digital modulation and other digital processing). Similarly, the radio components may implement one or more receive chains and transmit chains using the aforementioned hardware.

[0086] In some embodiments, the UE 106 may include a separate transmit chain and / or receive chain (e.g., including separate antennas and other radio components) for each wireless communication protocol with which it is configured to communicate. As another possibility, the UE 106 may include one or more radio components shared between multiple wireless communication protocols, and one or more radio components used uniquely by a single wireless communication protocol. For example, the UE 106 may include shared radio components for communicating using any of LTE or CDMA2000 1xRTT (or LTE or NR, or LTE or GSM), and shared radio components for communicating using Wi-Fi and BLUETOOTH.TM Each of the radio components communicates with each other. Other configurations are also possible.

[0087] Figure 3 - Block diagram of an exemplary UE device

[0088] Figure 3 A block diagram of an exemplary UE 106 according to some embodiments is shown. As shown, the UE 106 may include a system on a chip (SOC) 300, which may include components for various purposes. For example, as shown, the SOC 300 may include a processor 302 that can execute program instructions for the UE 106, and a display circuit 304 that can perform graphics processing and provide display signals to a display 360. The SOC 300 may also include sensor circuitry 370, which may include components for sensing or measuring any of various possible characteristics or parameters of the UE 106. For example, the sensor circuitry 370 may include motion sensing circuitry configured to detect the motion of the UE 106, for example, using a gyroscope, an accelerometer, and / or any of various other motion sensing components. As another possibility, the sensor circuitry 370 may include one or more temperature sensing components, for example, for measuring the temperature of each of one or more antenna panels and / or other components of the UE 106. Any of various other possible types of sensor circuitry may also or alternatively be included in the UE 106, as desired. Processor 302 may also be coupled to a memory management unit (MMU) 340, which may be configured to receive addresses from processor 302 and translate those addresses into locations in memory (e.g., memory 306, read-only memory (ROM) 350, NAND flash memory 310) and / or other circuits or devices, such as display circuitry 304, radio circuitry 330, connector interface (I / F) 320, and / or display 360. MMU 340 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 340 may be included as part of processor 302.

[0089] As shown, the SOC 300 may be coupled to various other circuits of the UE 106. For example, the UE 106 may include various types of memory (e.g., including NAND flash memory 310), a connector interface 320 (e.g., for coupling to a computer system, a docking station, a charging station, etc.), a display 360, and radio circuitry 330 (e.g., for LTE, LTE-A, NR, CDMA2000, BLUETOOTH, etc.). TM, Wi-Fi, GPS, etc.). The UE device 106 may include at least one antenna (e.g., 335a), and may include multiple antennas (e.g., as shown by antennas 335a and 335b), for performing wireless communications with base stations and / or other devices. Antennas 335a and 335b are shown by way of example, and the UE device 106 may include fewer or more antennas. In general, one or more antennas are collectively referred to as antennas 335. For example, the UE device 106 may use antennas 335 with the aid of radio circuitry 330 to perform wireless communications. As described above, in some embodiments, the UE may be configured to perform wireless communications using multiple wireless communication standards.

[0090] The UE 106 may include hardware and software components for implementing the method for the UE 106 to perform techniques such as those described further below herein for improving the reliability of multicast and broadband service (MBS) communications. The processor 302 of the UE device 106 may be configured to implement part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). In other embodiments, the processor 302 may be configured as a programmable hardware element, such as an FPGA (field programmable gate array) or as an ASIC (application-specific integrated circuit). In addition, the processor 302 may be coupled to a processor such as a processor 102 or a processor 103. Figure 3 Other components are shown and / or may interoperate with other components to perform techniques for improving reliability of MBS communications according to various embodiments disclosed herein. Processor 302 may also implement various other applications and / or end-user applications running on UE 106.

[0091] In some embodiments, the radio circuitry 330 may include separate controllers dedicated to controlling communications for various corresponding RAT standards. Figure 3 As shown, the radio circuit 330 may include a Wi-Fi controller 352, a cellular controller (eg, LTE and / or NR controller) 354, and a BLUETOOTH controller. TM Controller 356 and in at least some embodiments, one or more or all of these controllers may be implemented as respective integrated circuits (ICs or chips) that communicate with each other and with SOC 300 (more specifically, with processor 302). For example, Wi-Fi controller 352 may communicate with cellular controller 354 via a cell-ISM link or WCI interface, and / or BLUETOOTH controller 354 may communicate with the cellular controller 354 via a cell-ISM link or WCI interface. TMThe controller 356 may communicate with the cellular controller 354 via a cell-ISM link, etc. Although three separate controllers are shown within the radio circuitry 330, other embodiments with fewer or more similar controllers for various different RATs may be implemented in the UE device 106. In some embodiments, the cellular controller 354 may include a baseband processor configured to implement or cause the UE 106 to implement one or more of the processes disclosed herein, or portions thereof.

[0092] Figure 4 - Block diagram of an exemplary base station

[0093] Figure 4 1 shows a block diagram of an exemplary base station 102 according to some embodiments. Note that Figure 4 The base station 102 is only one example of a possible base station. As shown, the base station 102 may include a processor 404 that may execute program instructions for the base station 102. The processor 404 may also be coupled to a memory management unit (MMU) 440 or other circuit or device that may be configured to receive addresses from the processor 404 and translate those addresses into locations in memory (e.g., memory 460 and read-only memory (ROM) 450).

[0094] The base station 102 may include at least one network port 470. The network port 470 may be configured to couple to a telephone network and provide access to the telephone network as described above. Figure 1 and Figure 2 The network port 470 may be configured to couple to a plurality of devices such as the UE device 106 to the telephone network described in the embodiment of the present invention. The network port 470 (or an additional network port) may also or alternatively be configured to couple to a cellular network, such as a core network of a cellular service provider. The core network may provide mobility-related services and / or other services to a plurality of devices such as the UE device 106. In some cases, the network port 470 may be coupled to the telephone network via the core network, and / or the core network may provide the telephone network (e.g., in other UE devices served by the cellular service provider).

[0095] The base station 102 may include at least one antenna 434 and possibly multiple antennas. One or more antennas 434 may be configured to operate as a wireless transceiver and may be further configured to communicate with the UE device 106 via the radio component 430. The antenna 434 communicates with the radio component 430 via a communication chain 432. The communication chain 432 may be a receive chain, a transmit chain, or both. The radio component 430 may be designed to communicate via various wireless telecommunication standards, including but not limited to NR, LTE, LTE-A WCDMA, CDMA2000, etc. The processor 404 of the base station 102 may be configured to implement and / or support implementation of part or all of the methods described herein, for example, by executing program instructions stored on a memory medium (e.g., a non-transitory computer-readable memory medium). Alternatively, the processor 404 may be configured as a programmable hardware element such as an FPGA (field programmable gate array), or as an ASIC (application-specific integrated circuit), or a combination thereof. In the case of certain RATs (e.g., Wi-Fi), the base station 102 may be designed as an access point (AP), in which case the network port 470 may be implemented to provide access to a wide area network and / or one or more local area networks, for example, it may include at least one Ethernet port, and the radio component 430 may be designed to communicate according to the Wi-Fi standard.

[0096] HARQ-ACK for MBS communications

[0097] As cellular spectrum usage increases, multicast and broadcast services (MBS) are becoming a more popular solution for improving resource efficiency when a base station has information to convey to multiple UEs. In traditional systems such as LTE, MBS communications do not utilize reception feedback, such as the transmission of ACK / NACK signals. However, as MBS becomes more prevalent, it is desirable to improve the reliability of MBS communications, which can be achieved in part by using such reception feedback. Because MBS communications are intended to include multiple recipients, providing reception feedback can pose various technical difficulties. The following methods and systems address such difficulties.

[0098] Unicast communication represents an example of peer-to-peer (PTP) communication, e.g., directed from a base station (such as base station 102) to a single UE (such as UE 106). In contrast, MBS communication represents an example of single-cell point-to-multipoint (PTM) communication, e.g., a single base station (such as base station 102) communicating with multiple UEs (such as UEs 106A-106N). In some MBS scenarios, base station 102 may broadcast a message to all UEs capable of receiving the message. In other MBS scenarios, base station 102 may multicast the communication by addressing it to multiple or a limited group of UEs.

[0099] At a high level, reception feedback (such as HARQ-ACK) is used to confirm the receipt of a message. For example, if base station 102 sends a message to UE 106, UE 106 may respond with an acknowledgment (ACK) message if the message was successfully received, and / or a negative acknowledgment (NACK) message if the message was corrupted, distorted, or otherwise not successfully received. In response to a NACK, in some scenarios, base station 102 may retransmit the original message or a similar message containing relevant data from the original message.

[0100] In situations where the base station 102 transmits an MBS message (e.g., a PTM message) to a group of UEs 106A-N, receiving feedback (such as ACK / NACK messages from the individual UEs) may introduce significant congestion and / or collision risk. Additionally, the base station 102 may have additional options in response to receiving one or more NACK messages in response to an MBS message. For example, in some scenarios, the base station 102 may respond to receiving one or more MBS NACK messages by retransmitting the original PTM message to the UEs 106A-N. In other scenarios, the base station 102 may respond to receiving one or more MBS NACK messages by retransmitting the original message or a relevant portion thereof as a PTP message to the UE that sent the MBS NACK message. In some scenarios, the base station 102 may receive multiple MBS NACK messages from multiple UEs and may respond by sending a corresponding PTP message to each UE from which an MBS NACK message was received. In some scenarios, such as in a highly congested environment, receiving feedback and / or retransmission of MBS messages may be undesirable. Therefore, in the context of MBS communications, additional signaling and control procedures may be beneficial in addition to those previously used for unicast feedback control.

[0101] Figure 6 to Figure 5 —Method for providing reception feedback for MBS communications

[0102] Figures 5 and 6 An exemplary methodology is presented for managing various aspects of receiving feedback for MBS communications. Figure 5 A flow chart illustrating an exemplary method for managing MBS reception feedback according to some embodiments is shown. Figure 5 The method may be performed by a base station (such as base station 102), or by a portion thereof (such as processor 404, radio component 430 and / or communication link 432). Figure 6 A flow chart illustrating an example method for providing MBS reception feedback according to some embodiments is shown. Figure 6 The method may be performed by a UE (such as UE 106A), or by a portion thereof (such as radio circuit 330). In some scenarios, Figure 6 The method may be performed by UE 106A when operating in RRC_CONNECTED mode.

[0103] In some scenarios, Figure 5 Methods and Figure 6 The method may be synchronous, such that base station 102 performs Figure 5 method, while UE 106A executes Figure 6 However, it should be understood that the base station 102 and the UE 106A are independent entities and each can operate independently of the other. For example, in some scenarios, the base station 102 can operate according to Figure 5 The method is to operate according to different Figure 6 UE communication according to the method shown; and in some scenarios, UE106A can Figure 6 The method is to operate according to different Figure 5 The method shown operates to communicate with a base station.

[0104] like Figure 5 As shown, at 502, base station 102 may select configuration parameters related to MBS reception feedback. Specifically, base station 102 may select configuration parameters related to the MBS HARQ-ACK protocol for a specific MBS service. In some scenarios, selecting the configuration parameters may be based in part or in whole on one or more determinations made by base station 102. In some scenarios, selecting the configuration parameters may be based on instructions received from another network entity.

[0105] As an example of such configuration parameters, in some implementations, the base station 102 may select whether to enable or disable MBS reception feedback (e.g., HARQ-ACK feedback) for MBS services. This determination may be based on one or more factors, such as cell congestion, reception quality, and / or various other factors. In other implementations, the base station 102 may not have the option to disable MBS reception feedback.

[0106] For another example, when base station 102 receives an MBS NACK message from one or more UEs in response to an initial transmission of an MBS data communication, base station 102 may select parameters for retransmission of the MBS data communication (e.g., payload communication of an MBS service). For example, in some scenarios, base station 102 may select parameters such that base station 102 retransmits the original MBS data communication to a group of original recipients in response to receiving an MBS NACK message from one or more UEs. This option may be selected, for example, when base station 102 expects to receive MBS NACK messages from multiple UEs, or when base station 102 may have difficulty determining which UE sent the MBS NACK message, as well as in other scenarios. For another example, in some scenarios, base station 102 may select parameters such that, in response to receiving an MBS NACK message from a UE, base station 102 retransmits the original MBS or a relevant portion thereof as a unicast communication addressed to the UE that sent the MBS NACK message. For example, in cases where base station 102 expects only one (or a few) identifiable UEs to send an MBS NACK message, as well as in other scenarios, base station 102 may select this option. For another example, base station 102 may select parameters such that base station 102 does not retransmit (e.g., omit) the original MBS in response to receiving an MBS NACK message from a UE. For example, in cases where signal congestion is high and / or communication fidelity of the MBS service is not important, as well as in other scenarios, base station 102 may select this option. In some scenarios, base station 102 may enable MBS reception feedback, for example, to inform decisions regarding scheduling, communication parameters, etc., even if base station 102 will not retransmit in response to an MBS NACK.

[0107] At 504, base station 102 may transmit some or all of the MBS configuration parameters selected at 502 to a plurality of UEs 106A-N, which are recipients of MBS services. Transmitting 504 may include one or more transmissions. For example, in some scenarios, base station 102 may transmit an MBS configuration message indicating the MBS configuration parameters. Alternatively or in addition, base station 102 may include an indication of one or more MBS configuration parameters within an MBS data communication.

[0108] For example, the base station 102 may transmit a message in which higher layer signaling indicates whether MBS reception feedback is enabled or disabled for the MBS service. Alternatively, the indication of whether MBS reception feedback is enabled or disabled may be provided as a bit in a field (e.g., a HARQ-ACK usage field) in a downlink control information (DCI) format for MBS scheduling. Alternatively, the indication of whether MBS reception feedback is enabled or disabled may be provided as a field in a medium access control (MAC) control element (CE), such as an MBS physical downlink shared channel (PDSCH).

[0109] For another example, base station 102 may transmit a message including an indication of selected parameters for retransmitting MBS data communications in response to an MBS NACK message. For example, the indication may be included in a DCI for MBS data scheduling. For another example, the indication may be included in a MAC CE. For example, a new MAC CE may be introduced that includes an MBS identifier (ID) of an MBS service and an indication of selected MBS retransmission parameters. For another example, the indication may be included in any of various other configuration or control fields, headers, and the like.

[0110] In some scenarios, the indication of the selected MBS retransmission procedure may consist of a single bit. For example, a value of "0" may indicate that the base station 102 will respond to the MBS NACK message by retransmitting the original MBS data communication, while a value of "1" may indicate that the base station 102 will respond to the MBS NACK message by sending a unicast message to the UE from which the MBS NACK message was received (or vice versa). In other scenarios, the indication of the MBS retransmission procedure may include additional bits, for example, to allow for signaling other options, such as signaling that the base station 102 will respond to the MBS NACK message without retransmitting. In some scenarios, the indication of the selected MBS retransmission procedure may take another form, such as including additional control fields or other information.

[0111] like Figure 6 As shown, at 604, UE 106A may receive the transmitted configuration parameters from base station 102. In this scenario, UE 106A is one of UEs 106A-N that are recipients of MBS services.

[0112] At 506, base station 102 may transmit an MBS data communication. The MBS data communication may include a data payload for the MBS service. In some scenarios, the MBS data communication may also indicate some or all of the selected MBS configuration parameters, such that 504 and 506 occur in the same transmission. In other scenarios, 504 and 506 may comprise different transmissions.

[0113] At 606, UE 106A may receive an MBS data communication from base station 102. At 608, UE 106A may determine whether to enable MBS reception feedback for the MBS associated with the MBS data communication received at 606. This determination may be based on the configuration parameters received at 604. It should be understood that functionally, this determination may be made at this time or at some other time, such as when the configuration parameters are received at 604. In some implementations, for example, where MBS reception feedback cannot be disabled, this determination may be omitted from the method.

[0114] If UE 106A determines at 608 that reception feedback is not enabled, UE 106A may forgo performing reception feedback at 610. For example, the UE may not perform further analysis on the MBS reception feedback and / or may not send MBS reception feedback on the MBS data communication received at 606.

[0115] If UE 106A determines at 608 that reception feedback is enabled, UE 106A may determine at 612 whether the MBS data communication received at 606 is corrupted. For example, UE 106A may determine that the MBS data communication is corrupted if a checksum process or other reception verification process fails.

[0116] In response to determining that the MBS data communication is not corrupted, the UE 106A may then continue to process the received MBS data communication at 614, e.g., by demodulating and decoding the communication, extracting payload data, etc. In some implementations, the UE 106A may send an MBS ACK message to the base station 102. However, in other implementations, the UE 106A may not send an MBS ACK message at 614. Specifically, in some implementations, the system may be configured to utilize only negative feedback (e.g., a NACK message) in the event of a reception failure, and not utilize positive feedback (e.g., an ACK message) in the event of a successful reception. Such a configuration may reduce network traffic and may reduce power consumption of the UE 106A.

[0117] In response to determining at 612 that the MBS data communication is corrupted, the UE 106A may send an MBSNACK message to the base station 102 at 616 .

[0118] At 516, base station 102 may receive the MBS NACK message. It should be understood that in scenarios where one of UEs 106A-N does not send an MBS NACK, 516 and subsequent elements may be omitted. In some scenarios, if base station 102 does not receive an MBS NACK from UE 106A at 516, base station 102 may proceed as if UE 106A correctly received the MBS data communication. That is, base station 102 may determine that UE 106A correctly received the MBS data communication in response to not receiving an MBS NACK in response to the MBS data communication from UE 106A.

[0119] The NACK message may be sent according to various formats.

[0120] As a first option, the NACK message can be sent via the PUCCH. For example, the NACK message can be sent using ACK / NACK PUCCH resources specifically allocated for MBS services. For example, the ACK / NACK PUCCH resources can include a specific combination of time / frequency resources and / or formats. In some implementations, the ACK / NACK PUCCH resources can be indicated or configured via radio resource control (RRC) messaging (such as in PUCCH-Config), for example, at 604 or at some other time. In some implementations, all UEs 106A-N receiving MBS services can use the same ACK / NACK PUCCH resources. For example, all UEs 106A-N can transmit on the resource simultaneously. The base station 102 can detect the energy of the PUCCH and can determine whether any of the UEs 106A-N has sent an MBS NACK. This option can be well suited for scenarios where the base station 102 will respond to the NACK by retransmitting the original MBS data communication (as opposed to responding with one or more unicast transmissions). In other implementations, the UEs 106A-N may be organized into subgroups, with different ACK / NACK PUCCH resources configured for each subgroup. In this way, the base station can easily determine the subset of UEs from which a NACK was sent and can respond to the NACK by retransmitting (e.g., as a unicast communication) only to the applicable subset. A non-limiting example of an RRC information element (IE) structure for configuring common PUCCH resources for MBS services is as follows:

[0121]

[0122] In another variation of the first option, the NACK message may be sent at 616 using ACK / NACK PUCCH resources specifically assigned to UE 106A. Thus, each of UEs 106A-N may use different assigned resources to send NACKs (if applicable). For example, UE 106A may send a NACK at 616 via PUCCH resources specifically assigned to UE 106A by base station 102 for providing reception feedback for MBS services. As another example, UE 106A may send a NACK via PUCCH resources configured for unicast physical uplink shared channel (PUSCH). In this example, the resources to be used may be indicated by base station 102, for example, via a MAC CE included in the MBS PDSCH. For example, a new field (e.g., a 4-bit "PUCCH resource indicator" field) may be included in the MAC CE. A non-limiting example of an RRC information element (IE) structure for configuring PUCCH resources assigned to UE 106A for MBS services is as follows:

[0123]

[0124] As a second option, the NACK message may be sent via the unicast PUSCH of UE 106A. For example, if the PUCCH according to the first option would collide in time with the unicast PUSCH, UE 106A may instead send an MBSNACK in the PUSCH, and the PUCCH may be omitted (e.g., may not be sent). As an example, an MBS NACK may be included in the MAC CE of the unicast PUSCH. In some scenarios, the MAC CE may also include additional information, such as MCCH / MTCH reception statistics or other statistical reports, e.g., the ratio or number of successful or unsuccessful MBS communications received by UE 106A. For example, UE 106A may record the total number of MBS messages received and the number of corrupted MBS messages received in a particular time period (e.g., in conjunction with applicable MBS services), and may report relevant information (e.g., number, ratio, etc.) periodically or when the failure rate meets a predetermined threshold. In some scenarios, such MAC CE may be configured to include the MBS ID of the MBS service, one or more bits for transmitting MBS NACK, and / or a field indicating additional information (such as MCCH / MTCH reception statistics).

[0125] In another variation of the second option, one or more bits representing the MBS NACK may be multiplexed on the HARQ-ACK field of the unicast PDSCH of UE 106A. For example, the MBS NACK may be added as the least significant bit (LSB) of the HARQ-ACK field, with the most significant bit (MSB) being occupied by the unicast HARQ-ACK feedback of UE 106A. In other examples, the bits may be ordered differently.

[0126] In some scenarios, other conflicts may also need to be resolved or prevented. For example, if UE 106A sends an MBS NACK via PUCCH, for example, according to option 1 above, there may be a chance that this PUCCH for MBS may be provided for transmission in the same time slot as a unicast PUCCH. This may be considered a conflict because two PUCCHs may not be allowed in the same time slot. In some scenarios, in response to detecting such a conflict, UE 106A may prioritize the unicast PUCCH transmission and forgo sending the MBS NACK. In other scenarios, UE 106A may prevent such conflicts by multiplexing one or more MBS NACK bits with the unicast HARQ-ACK bits of the unicast PUCCH, or may respond to detecting such a conflict. PUCCH resources may be derived from a configured PUCCH resource set. In some implementations, the ordering of unicast and MBS HARQ-ACK bits may be predefined; for example, the LSB may be used for HARQ-ACK for MBS. In some implementations, the ordering of the HARQ-ACK bits may be defined by the base station 102. For example, the base station 102 may provide, for example at 504, a bitmap or other indication of the expected ordering of the HARQ-ACK bits.

[0127] As another example, in some scenarios, UE 106A may receive MBS data communications for more than one MBS service. In this case, UE 106A may have MBS reception feedback to report on more than one MBS data communication simultaneously. In such scenarios, each MBS service may be associated with an MBS ID. In some implementations, such conflicts may be resolved by selecting only one NACK message to send. For example, UE 106A may send a NACK message for the MBS with the lowest (or highest) MBS ID, while omitting (e.g., not sending) NACK messages for other MBS services. As another example, UE 106A may determine which NACK message to send based on, for example, design-specific factors. In other implementations, HARQ-ACK bits for all MBS services may be multiplexed on the PUCCH. For example, the HARQ-ACK bits may be organized by MBS ID. If an MBS ID is defined for an MBS service to which UE 106 is not subscribed, UE 106 may indicate a NACK for the associated bit. In some scenarios, the ACK / NACK message may be sent via the PUCCH resources allocated for the MBS service with the lowest (or highest) MBS ID.In some scenarios, the PUCCH resources to be used may be selected in some other way.

[0128] In some scenarios, the UE 106A can determine, for example, at 612 or at some other time after 606, that the UE 106A is not synchronized with the base station 102. In some implementations, the UE 106A can respond to this determination by triggering a physical random access channel (PRACH) procedure to synchronize with the network and can forgo sending any MBS reception feedback (ACK or NACK) in response to the MBS data communication received at 606.

[0129] At 518, the base station 102 may respond to the MBS NACK received at 516. The response may be based at least in part on the configuration parameters selected at 502. For example, if the selected parameters for retransmission of the MBS data communication indicate that the base station 102 will respond to the MBS NACK by retransmitting the original MBS data communication, responding to the MBS NACK at 518 may include retransmitting the original MBS data communication, e.g., addressed to the same set of UEs 106A-N as the original MBS data communication sent at 506. The retransmission may utilize resources allocated for MBS services, such as the SC-MTCH or other MBS downlink data channel.

[0130] For another example, if the selected parameters for the retransmission of the MBS data communication indicate that the base station 102 will respond to the MBS NACK by sending a unicast message to the UE from which the MBS NACK message was received, responding to the MBS NACK at 518 may include sending at least some portions of the original MBS data communication, but formatted as a unicast message addressed to the UE 106A. The unicast message may utilize resources allocated for unicast message transmission to the UE 106A, such as the PDSCH or other unicast downlink data channel. In some scenarios, the base station 102 may receive more than one MBS NACK message from more than one of the UEs 106A-N and may respond by sending a corresponding unicast message to each UE from which the MBS NACK message was received.

[0131] For another example, if the selected parameters for retransmission of the MBS data communication indicate that the base station 102 will not retransmit the MBS data communication in response to the MBSNACK message, then responding to the MBS NACK at 518 may include not retransmitting the MBS data communication. However, in this scenario and other scenarios, responding to the MBS NACK at 518 may also include additional tasks, such as storing a record of the MBS NACK message and / or additional information included in the MBS NACK message, such as MCCH / MTCH reception statistics. Responding at 518 may also include adjusting network parameters based on the MBS NACK message and / or associated information.

[0132] At 618, UE 106A may monitor for retransmissions of MBS data communications based on the configuration parameters received at 606. For example, if the configuration parameters indicate that base station 102 will respond to an MBS NACK by retransmitting the original MBS data communication, UE 106A may monitor appropriate resources allocated for MBS services, such as the SC-MTCH or other MBS downlink data channels. Monitoring appropriate resources may include, for example, placing appropriate hardware and / or software in an appropriate receiving state (e.g., an awake state) during a time window in which the appropriate resources are scheduled to be received. Monitoring appropriate resources may also include receiving, demodulating, decoding, etc., signals received on these resources. Specifically, monitoring appropriate resources may include receiving retransmissions of MBS data communications.

[0133] For another example, if the configuration parameters indicate that the base station 102 will respond to the MBS NACK by sending a unicast message to the UE from which the MBS NACK message was received, the UE may monitor appropriate resources allocated for unicast message transmission to the UE 106A, such as the PDSCH or other unicast downlink data channels. Monitoring the appropriate resources may also include receiving, demodulating, decoding, etc., signals received on these resources. Specifically, monitoring the appropriate resources may include receiving a transmission of at least a portion of the MBS data communication that is retransmitted as a unicast message addressed to the UE 106A.

[0134] As another example, if the configuration parameters indicate that the base station 102 is not to retransmit MBS data communications in response to an MBS NACK message, the UE 106A may not monitor the resources to receive such retransmissions.

[0135] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly stated to users.

[0136] By interpreting each message / signal X received by a user equipment (UE) in the downlink as a message / signal X transmitted by the base station, and interpreting each message / signal Y transmitted by the UE in the uplink as a message / signal Y received by the base station, any of the methods for operating a UE described herein may become the basis for the corresponding method for operating a base station.

[0137] The embodiments of the present disclosure may be implemented in any of a variety of forms. For example, in some embodiments, the subject matter may be implemented as a computer-implemented method, a computer-readable storage medium, or a computer system. In other embodiments, the subject matter may be implemented using one or more custom-designed hardware devices such as ASICs. In other embodiments, the subject matter may be implemented using one or more programmable hardware elements such as FPGAs.

[0138] In some embodiments, a non-transitory computer-readable storage medium (e.g., a non-transitory memory element) may be configured such that it stores program instructions and / or data, wherein the program instructions, if executed by a computer system, cause the computer system to perform a method, such as any of the method embodiments described herein, or any combination of the method embodiments described herein, or any subset of any method embodiments described herein, or any combination of such subsets.

[0139] In some embodiments, a device (e.g., a UE) may be configured to include a processor (or a group of processors) and a memory medium (or a memory element), wherein the memory medium stores program instructions, wherein the processor is configured to read and execute the program instructions from the memory medium, wherein the program instructions are executable to implement any of the various method implementations described herein (or any combination of the method implementations described herein, or any subset of any method implementations described herein, or any combination of such subsets). The device may be implemented in any of various forms.

[0140] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to encompass all such variations and modifications.

Claims

1. A device for wireless communication, the device comprising: a processor configured to cause the base station to: selecting a retransmission process for a multicast and broadcast service (MBS) service from a plurality of retransmission processes; sending an indication of the selected retransmission process to a plurality of user equipments (UEs), wherein when the indication indicates a first process, the corresponding UEs are caused to monitor resources allocated for MBS communications for retransmissions of MBS data, and when the indication indicates a second process, the corresponding UEs are caused to monitor resources allocated for unicast communications to the UEs for retransmissions of MBS data; sending MBS data communications for the MBS service to the plurality of UEs; receiving a negative acknowledgement (NACK) message in response to the MBS data communication from a first UE among the plurality of UEs; and Responding to the received NACK message based on the selected retransmission process, wherein responding to the received NACK message comprises: retransmitting MBS data transmission using resources allocated for the MBS service when the selected retransmission procedure is the first procedure; and When the selected retransmission procedure is the second procedure, the MBS data communication is retransmitted using resources allocated for unicast transmission to the first UE.

2. The apparatus of claim 1 , wherein responding to the received NACK message comprises: When the selected retransmission process is the third process, the MBS data communication is not retransmitted. 3 . The apparatus of claim 1 , wherein the NACK message is received via a physical uplink control channel (PUCCH) resource allocated for the MBS service.

4. The apparatus according to claim 3, wherein the processor is configured to cause the base station to: An additional NACK message is received from a second UE among the plurality of UEs, wherein the additional NACK message is received via the same PUCCH resource allocated for the MBS service. 5 . The apparatus of claim 3 , wherein the PUCCH resources are allocated for MBS reception feedback by a subgroup of the plurality of UEs, wherein the first UE is included in the subgroup. 6 . The apparatus of claim 1 , wherein the NACK message is sent using a physical uplink control channel (PUCCH) resource allocated to the first UE for reception feedback of an MBS message received by the first UE.

7. The apparatus of claim 1, wherein the NACK message is sent using a physical uplink control channel (PUCCH) resource allocated to the first UE for reception feedback of a unicast message received by the first UE.

8. The apparatus of claim 1, wherein the NACK message is sent using a unicast Physical Uplink Shared Channel (PUSCH).

9. The apparatus of claim 1 , wherein the processor is configured to cause the base station to: receiving, from the first UE, reception statistics regarding messages associated with the MBS service received by the first UE, wherein: The reception statistics include at least a ratio or number of successful or unsuccessful MBS communications received by the first UE.

10. The apparatus of claim 1, wherein the indication of the selected retransmission process is sent in a downlink control indicator (DCI) for MBS data scheduling.

11. The apparatus of claim 1 , wherein the indication of the selected retransmission procedure is sent in a medium access control (MAC) control element (CE).

12. A method for managing multicast and broadcast service (MBS) reception feedback, the method comprising: By base stations of wireless communication networks: Selecting a retransmission process for the MBS service from a plurality of available retransmission processes; sending an indication of the selected retransmission process to a plurality of user equipments (UEs), wherein when the indication indicates a first process, the corresponding UEs are caused to monitor resources allocated for MBS communications for retransmissions of MBS data, and when the indication indicates a second process, the corresponding UEs are caused to monitor resources allocated for unicast communications to the UEs for retransmissions of MBS data; sending MBS data communications for the MBS service to the plurality of UEs; receiving a negative acknowledgement (NACK) message in response to the MBS data communication from a first UE among the plurality of UEs; and Responding to the received NACK message based on the selected retransmission process, wherein responding to the received NACK message comprises: retransmitting MBS data transmission using resources allocated for the MBS service when the selected retransmission procedure is the first procedure; and When the selected retransmission procedure is the second procedure, the MBS data communication is retransmitted using resources allocated for unicast transmission to the first UE.

13. The method of claim 12, wherein the NACK message is received via a physical uplink control channel (PUCCH) resource allocated for the MBS service, the method further comprising: An additional NACK message is received from a second UE among the plurality of UEs, wherein the additional NACK message is received via the same PUCCH resource allocated for the MBS service.

14. The method of claim 12, wherein the NACK message is sent using a physical uplink control channel (PUCCH) resource that is allocated specifically to the first UE for reception feedback for communications received by the first UE.

15. The method of claim 12, wherein the indication of the selected retransmission process is sent in at least one of: Downlink Control Indicator (DCI) for MBS data scheduling; or Medium Access Control (MAC) Control Element (CE).

16. An apparatus for wireless communication, the apparatus comprising: A processor configured to cause a user equipment (UE): receiving a multicast and broadcast service (MBS) data transmission related to an MBS service from a base station; sending a negative acknowledgement (NACK) message to the base station in response to determining that reception of the MBS data transmission is corrupted; as well as monitoring a retransmission of the MBS data transmission in response to the NACK message, wherein the monitoring comprises: monitoring resources allocated for MBS communication when the indication of the MBS retransmission process provided by the base station has a first value; as well as When the indication of the MBS retransmission process has a second value, resources allocated for unicast communication to the UE are monitored.

17. The apparatus of claim 16, wherein the indication of the MBS retransmission process is received in one of: Downlink Control Indicator (DCI) for MBS data scheduling; or Medium Access Control (MAC) Control Element (CE).

18. The apparatus according to claim 16, wherein the processor is configured to cause the UE to: An acknowledgement (ACK) message is not sent in response to determining that the MBS data transmission is correctly received.

19. The apparatus of claim 16, wherein the NACK message is transmitted using an ACK / NACK Physical Uplink Control Channel (PUCCH) resource allocated for common use by UEs subscribed to the MBS service.

20. The apparatus of claim 16, wherein in response to determining that sending the NACK message on an ACK / NACK physical uplink control channel (PUCCH) resource would collide in time with a unicast physical uplink shared channel (PUSCH), the NACK message is sent using the unicast PUSCH.

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