Mixed-mode broadcast / multicast communications

Abstract

Various aspects of the present disclosure generally relate to wireless communications. In some aspects, a user equipment (UE) may determine that a negative acknowledgement (NACK) feedback message for a broadcast / multicast communication will be transmitted. The UE may transmit the NACK feedback message to a broadcast / multicast control plane function device of a core network via a radio access network (RAN) based at least in part on determining that a NACK feedback message will be transmitted. The UE may receive a retransmission of a broadcast / multicast communication based at least in part on transmitting a NACK feedback message. Numerous other aspects are provided.

Description

[0001] Public domain

[0002] Aspects of the present disclosure relate generally to wireless communications and, more particularly, to techniques and apparatus for mixed-mode broadcast or multicast (broadcast / multicast) communications.

[0003] background

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, or transmit power, etc., or a combination thereof). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0005] The above multiple access technologies have been adopted in various telecommunication standards to provide common protocols that enable different user equipment (UE) to communicate at city, country, region, and even global levels. New Radio (NR) (which may also be referred to as 5G) is an enhancement set to the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink (DL), using CP-OFDM or SC-FDMA (e.g., also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple input multiple output (MIMO) antenna technology and carrier aggregation to improve spectrum efficiency, reduce costs, improve services, utilize new spectrum, and better integrate with other open standards. However, as the demand for mobile broadband access continues to grow, there is a need for further improvements in LTE and NR technologies. Preferably, these improvements are applicable to other multiple access technologies and telecommunication standards that employ these technologies.

[0006] In mobile broadcast or multicast (broadcast / multicast), forward error correction coding (FEC) may be used to achieve a level of broadcast / multicast communication reliability. FEC is a digital signal processing technique that introduces redundant data into transmissions. Accordingly, broadcast / multicast communications utilizing FEC may be relatively large, consuming additional network resources and UE processing resources.

[0007] Overview

[0008] In some aspects, a wireless communication method performed by a user equipment (UE) may include determining that a negative acknowledgement (NACK) feedback message for a broadcast or multicast (broadcast / multicast) communication will be transmitted. The method may include transmitting the NACK feedback message to a broadcast / multicast control plane function (BMCPF) device of a core network via a radio access network (RAN) based at least in part on determining that the NACK feedback message will be transmitted. The method may include receiving a retransmission of the broadcast / multicast communication based at least in part on transmitting the NACK feedback message.

[0009] In some aspects, a wireless communication method performed by a device of a core network may include using a BMCPF to receive a NACK feedback message for a broadcast / multicast communication transmitted to a UE. The method may include causing a retransmission of the broadcast / multicast communication based at least in part on receiving the NACK feedback message.

[0010] In some aspects, a UE for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to determine that a NACK feedback message for a broadcast / multicast communication will be transmitted. The memory and the one or more processors may be configured to transmit the NACK feedback message to a BMCPF device of a core network via a RAN based at least in part on determining that a NACK feedback message will be transmitted. The memory and the one or more processors may be configured to receive a retransmission of a broadcast / multicast communication based at least in part on transmitting the NACK feedback message.

[0011] In some aspects, a core network device for wireless communication may include a memory and one or more processors operatively coupled to the memory. The memory and the one or more processors may be configured to use a BMCPF to receive a NACK feedback message for a broadcast / multicast communication transmitted to a UE. The memory and the one or more processors may be configured to cause a retransmission of the broadcast / multicast communication based at least in part on receiving the NACK feedback message.

[0012] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a UE, may cause the one or more processors to determine that a NACK feedback message for a broadcast / multicast communication will be transmitted. The one or more instructions may cause the one or more processors to transmit the NACK feedback message to a BMCPF device of a core network via a RAN based at least in part on determining that a NACK feedback message will be transmitted. The one or more instructions may cause the one or more processors to receive a retransmission of a broadcast / multicast communication based at least in part on transmitting the NACK feedback message.

[0013] In some aspects, a non-transitory computer-readable medium may store one or more instructions for wireless communication. The one or more instructions, when executed by one or more processors of a device of a core network, may cause the one or more processors to use a BMCPF to receive a NACK feedback message for a broadcast / multicast communication transmitted to a UE. The one or more instructions may cause the one or more processors to cause a retransmission of the broadcast / multicast communication based at least in part on receiving the NACK feedback message.

[0014] In some aspects, an apparatus for wireless communication may include means for determining that a NACK feedback message for a broadcast / multicast communication will be transmitted. The apparatus may include means for transmitting the NACK feedback message to a BMCPF device of a core network via a RAN based at least in part on determining that the NACK feedback message will be transmitted. The apparatus may include means for receiving a retransmission of the broadcast / multicast communication based at least in part on transmitting the NACK feedback message.

[0015] In some aspects, an apparatus for wireless communication may include means for receiving a NACK feedback message for a broadcast / multicast communication transmitted to a UE using a BMCPF. The apparatus may include means for causing a retransmission of the broadcast / multicast communication based at least in part on receiving the NACK feedback message.

[0016] Aspects generally include methods, apparatus, systems, computer program products, non-transitory computer readable media, user equipment, base stations, wireless communication devices, or processing systems as substantially described with reference to and as illustrated in the drawings and description.

[0017] The foregoing has broadly outlined the features and technical advantages of examples according to the present disclosure in an effort to make the following detailed description better understood. Additional features and advantages will be described hereinafter. The disclosed concepts and specific examples can be easily used as a basis for modifying or designing other structures for implementing the same purpose as the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, both in terms of their organization and method of operation, and the associated advantages will be better understood by considering the following description in conjunction with the accompanying drawings. Each of the accompanying drawings is provided for the purpose of illustration and description and is not intended to define limitations on the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to understand the above-stated features of the present disclosure in detail, the above briefly summarized content may be described in more detail with reference to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings illustrate only some typical aspects of the present disclosure and should not be considered to limit its scope, as the description may allow for other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0020] Figure 1 is a block diagram illustrating an example wireless network in accordance with various aspects of the present disclosure.

[0021] Figure 2 is a block diagram illustrating an example base station (BS) and user equipment (UE) in communication in a wireless network in accordance with various aspects of the present disclosure.

[0022] Figure 3 is a diagram illustrating an example functional architecture of a core network in accordance with various aspects of the present disclosure.

[0023] Figure 4 is a diagram illustrating an example of mixed mode broadcast or multicast (broadcast / multicast) communication according to various aspects of the present disclosure.

[0024] Figure 5 is a diagram illustrating an example functional architecture of a core network in accordance with various aspects of the present disclosure.

[0025] Figure 6 is a diagram illustrating an example of mixed mode broadcast / multicast communication in accordance with various aspects of the present disclosure.

[0026] Figure 7 is a flow chart illustrating an example process of mixed mode broadcast / multicast communication performed by a UE in accordance with various aspects of the present disclosure.

[0027] Figure 8 is a flow chart illustrating an example process of mixed mode broadcast / multicast communication performed by a device of a core network according to various aspects of the present disclosure.

[0028] Detailed Description

[0029] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be implemented in many different forms and is not interpreted as being limited to any specific structure or function given throughout the present disclosure. On the contrary, these aspects are provided to make the present disclosure thorough and complete, and it will fully convey the scope of the present disclosure to those skilled in the art. Based on the teachings of this article, those skilled in the art can appreciate that the scope of the present disclosure is intended to cover any aspect of the present disclosure disclosed herein, whether it is implemented independently or in combination with any other aspect of the present disclosure. For example, any number of aspects set forth herein can be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such devices or methods practiced using supplements or other other structures, functionality, or structures and functionality as the various aspects of the present disclosure set forth herein. Any aspect of the present disclosure disclosed herein can be implemented by one or more elements of the claims.

[0030] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, or algorithms, etc., or combinations thereof (collectively referred to as "elements"). These elements may be implemented using hardware, software, or a combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0031] In mobile broadcast or multicast (broadcast / multicast), forward error correction coding (FEC) can be used to achieve a level of broadcast / multicast communication reliability. FEC is a digital signal processing technique that introduces redundant data into transmission. For example, using FEC with 10% data redundancy can provide a 1% error rate for broadcast / multicast communication. However, in order to achieve a lower error rate, data redundancy must be further increased. As a result, highly reliable broadcast / multicast communications using FEC consume significant network resources and UE processing resources. This can lead to higher network congestion, lower throughput, and increased UE battery drain, etc.

[0032] Some techniques and devices described herein improve the reliability and resource consumption of broadcast / multicast communications. In some aspects, a UE may transmit negative acknowledgement (NACK) feedback for a broadcast / multicast communication to a broadcast / multicast control plane function (BMCPF) of a core network via a radio access network (RAN). In response to the NACK feedback, the BMCPF may cause another function of the core network to transmit a retransmission of the broadcast / multicast communication to the UE via the RAN. The retransmission may be a unicast retransmission or a broadcast / multicast retransmission based at least in part on the number of UEs that transmitted NACK feedback for the broadcast / multicast communication. In this way, network resources and processing resources of the UE may be saved.

[0033] Figure 1 1 is a block diagram illustrating an example wireless network according to various aspects of the present disclosure. The wireless network may be a long term evolution (LTE) network or some other wireless network, such as a 5G or NR network. The wireless network may include some base stations (BSs) 110 (shown as BSs 110a, BSs 110b, BSs 110c, and BSs 110d) and other network entities. A BS is an entity that communicates with a user equipment (UE) and may also be referred to as a B node, an evolved B node, an eNB, a gNB, an NR BS, a 5G B node (NB), an access point (AP), or a transmit receive point (TRP), etc., or a combination thereof (these terms are used interchangeably herein). Each BS may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to a coverage area of ​​a BS or a BS subsystem serving the coverage area, depending on the context in which the term is used.

[0034] A BS may provide communication coverage for a macro cell, a pico cell, a femto cell, or another type of cell. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG)). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. A BS may support one or more (e.g., three) cells.

[0035] The wireless network may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, or relay BSs, etc., or a combination thereof). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless network. For example, a macro BS may have a high transmit power level (e.g., 5 to 40 watts), while a pico BS, a femto BS, and a relay BS may have a lower transmit power level (e.g., 0.1 to 2 watts). Figure 1In the example shown in FIG. 1 , BS 110a may be a macro BS for macro cell 102a, BS 110b may be a pico BS for pico cell 102b, and BS 110c may be a femto BS for femto cell 102c. A network controller 130 may be coupled to the set of BSs 102a, 102b, 110a, and 110b, and may provide coordination and control of these BSs. The network controller 130 may communicate with each BS via a backhaul. The BSs may also communicate with each other, directly or indirectly, for example, via a wireless or wired backhaul.

[0036] In some aspects, the cell may not be stationary, but rather the geographic area of ​​the cell may move according to the location of the mobile BS. In some aspects, the BSs may be interconnected to each other or to one or more other BSs or network nodes (not shown) in the wireless network using any suitable transport network through various types of backhaul interfaces (such as direct physical connections, virtual networks, etc., or combinations thereof).

[0037] The wireless network may also include a relay station. A relay station is an entity that can receive transmissions of data from an upstream station (e.g., a BS or UE) and send transmissions of the data to a downstream station (e.g., a UE or BS). A relay station may also be a UE that can relay transmissions for other UEs. Figure 1 In the example shown in , a relay station 110d may communicate with a macro BS 110a and a UE 120d to facilitate communication between the BS 110a and the UE 120d. A relay station may also be referred to as a relay BS, a relay base station, or a relay, etc., or a combination thereof.

[0038] UE 120 (e.g., 120a, 120b, 120c) may be dispersed throughout the wireless network, and each UE may be stationary or mobile. UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, or station, etc., or a combination thereof. UE may be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device or equipment, a biometric sensor / device, a wearable device (smart watch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet)), an entertainment device (e.g., a music or video device, or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, or any other suitable device configured to communicate via a wireless medium.

[0039] Some UEs may be considered as machine type communication (MTC) UEs, or evolved or enhanced machine type communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, or location tags, etc., or a combination thereof, which may communicate with a base station, another device (e.g., a remote device), or some other entity. A wireless node may provide connectivity to or to a network (e.g., a wide area network (such as the Internet) or a cellular network), for example, via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, or may be implemented as NB-IoT (narrowband Internet of Things) devices. Some UEs may be considered as client equipment (CPE). UE 120 may be included within a housing that houses components of UE 120, such as a processor component, or a memory component, etc., or a combination thereof.

[0040] In general, any number of wireless networks may be deployed in a given geographic area. Each wireless network may support a specific radio access technology (RAT) and may operate on one or more frequencies or frequency channels. Frequencies may also be referred to as carriers, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0041] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may use one or more sidelink channels to communicate directly with each other (e.g., without using base station 110 as an intermediary). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, or vehicle-to-infrastructure (V2I) protocols, etc., or a combination thereof), or mesh networks, etc., or a combination thereof. In this case, UE 120 may perform scheduling operations, resource selection operations, or other operations described elsewhere herein as being performed by base station 110.

[0042] Figure 2 2 is a block diagram illustrating an example base station (BS) and user equipment (UE) in communication in a wireless network in accordance with various aspects of the present disclosure. Base station 110 may be equipped with T antennas 234a through 234t, and UE 120 may be equipped with R antennas 252a through 252r, where in general T≥1 and R≥1.

[0043] At the base station 110, the transmit processor 220 may receive data for one or more UEs from the data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on a channel quality indicator (CQI) received from the UE, process (e.g., encode) the data for the UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. The transmit processor 220 may also process system information (e.g., for semi-static resource partitioning information (SRPI) and control information (e.g., CQI requests, grants, or upper layer signaling, etc., or a combination thereof), and provide overhead symbols and control symbols. The transmit processor 220 may also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signals (PSS) and secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, or reference symbols where applicable, and may provide T output symbol streams to T modulators (MODs) 232a to 232t. Each MOD 232 may process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each MOD 232 may further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from MODs 232a to 232t may be transmitted via T antennas 234a to 234t, respectively. According to various aspects described in more detail below, position coding may be used to generate synchronization signals to convey additional information.

[0044] At UE 120, antennas 252a to 252r may receive downlink signals from base station 110 or other base stations, and may provide received signals to R demodulators (DEMODs) 254a to 254r, respectively. Each DEMOD 254 may condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain input samples. Each DEMOD 254 may further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from all R DEMODs 254a to 254r, perform MIMO detection on the received symbols where applicable, and provide detected symbols. A receive processor 258 may process (e.g., decode) the detected symbols, provide decoded data for UE 120 to a data sink 260, and provide decoded control information and system information to a controller / processor 280. The channel processor may determine reference signal received power (RSRP), received signal strength indicator (RSSI), reference signal received quality (RSRQ), or channel quality indicator (CQI), etc., or a combination thereof. In some aspects, one or more components of UE 120 may be included in a housing.

[0045] On the uplink, at the UE 120, a transmit processor 264 may receive and process data from a data source 262 and control information (e.g., for reports including RSRP, RSSI, RSRQ, or CQI, etc., or a combination thereof) from a controller / processor 280. The transmit processor 264 may also generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be precoded by a TX MIMO processor 266, if applicable, further processed by MODs 254a to 254r (e.g., for discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-s-OFDM), or orthogonal frequency division multiplexing (OFDM) with a cyclic prefix (CP) (CP-OFDM), etc., or a combination thereof), and transmitted to the base station 110. At the base station 110, uplink signals from the UE 120 and other UEs may be received by the antenna 234, processed by the DEMOD 232, detected by the MIMO detector 236 where applicable, and further processed by the receive processor 238 to obtain decoded data and control information sent by the UE 120. The receive processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240. The base station 110 may include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292.

[0046] The controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, the controller / processor 290 of the network controller 130, or Figure 2 Any other component of the network controller 130 may perform one or more techniques associated with mixed-mode broadcast / multicast communications, as described in greater detail elsewhere herein. For example, the controller / processor 240 of the base station 110, the controller / processor 280 of the UE 120, the controller / processor 290 of the network controller 130, or Figure 2 Any other component of the Figure 7 The process of 700 Figure 8 The operations of process 800 or other processes as described herein. Memories 242, 282, and 292 may store data and program codes for base station 110, UE 120, and network controller 130, respectively. Scheduler 246 may schedule UEs for data transmission on the downlink or uplink.

[0047] In some aspects, UE 120 may include means for determining that a NACK feedback message for a broadcast / multicast communication will be transmitted, means for transmitting the NACK feedback message to a BMCPF device of a core network via the RAN based at least in part on determining that the NACK feedback message will be transmitted, means for receiving a retransmission of the broadcast / multicast communication based at least in part on transmitting the NACK feedback message, and the like, or a combination thereof. In some aspects, such means may include in conjunction with Figure 2 One or more components of UE 120 are described.

[0048] In some aspects, an apparatus of the core network may include a means for using the BMCPF to receive a NACK feedback message for a broadcast / multicast communication transmitted to the UE, a means for causing a retransmission of the broadcast / multicast communication based at least in part on receiving the NACK feedback message, etc., or a combination thereof. In some aspects, such means may include a means for combining Figure 2 One or more components of a base station 110 or a network controller 130 are depicted.

[0049] As described above, some techniques and devices described herein improve the reliability and resource consumption of broadcast / multicast communications. In some aspects, the UE may transmit NACK feedback for broadcast / multicast communications to the BMCPF of the core network via the RAN. In response to the NACK feedback, the BMCPF may cause another function of the core network to transmit a retransmission of the broadcast / multicast communication to the UE via the RAN. The retransmission may be a unicast retransmission or a broadcast / multicast retransmission based at least in part on the number of UEs that transmitted NACK feedback for the broadcast / multicast communication. In this way, network resources and processing resources of the UE may be saved.

[0050] Figure 3 is a diagram illustrating an example functional architecture of a core network 305 according to various aspects of the present disclosure. In some aspects, the core network 305 may have an architecture that merges control plane and user plane functionality. Figure 3 As shown in FIG. 1 , the core network 305 may be in communication with the RAN 310 and the data network 315. The RAN 310 may include a base station (e.g., BS 110) and may be operably connected to the core network 305 via a wired or wireless connection. The RAN 310 may facilitate a communication session between the UE and the data network 315 by communicating application-specific data between the RAN 310 and the core network 305. The data network 315 may include one or more wired or wireless data networks. For example, the data network 315 may include the Internet, a third-party service network, an operator service network, a private network, or a wide area network, etc. In some aspects, the data network 315 may include a content delivery network (CDN) or one or more content servers. For example, the CDN or the one or more content servers may provide data for broadcast / multicast transmission.

[0051] The core network 305 may include various types of core network architectures, such as a 5G next generation (NG) core included in a 5G wireless telecommunications system. In some aspects, the core network 305 may be implemented on a physical device (such as a gateway or a mobility management entity, etc.). In some aspects, the hardware or software implementing the core network 305 may be virtualized. In some aspects, one or more devices implementing the core network 305 may be co-located with a base station (e.g., BS 110).

[0052] like Figure 3 As shown in , the core network 305 may include multiple functional elements. One or more of these functional elements of the core network 305 may be implemented on one or more devices (e.g., servers). These functional elements of the core network 305 may include an access and mobility management function (AMF) 320, a session management function (SMF) 325, a policy control function (PCF) 330, an application function (AF) 335, a broadcast / multicast coordination function (BMCF) 340, a user plane function (UPF) 345, or a broadcast / multicast function (BMF) 350. Figure 3 As shown in the figure, the RAN 310 can be connected to the core network 305 via the AMF 320, the UPF 345 or the BMCF 340.

[0053] AF 335 can determine whether the UE provides a preference for a network slice policy set and support the impact of the application on traffic routing, access to the network open functions of the core network 305, or policy control, etc. AMF 320 can provide registration and mobility management for UE. SMF 325 can support the establishment, modification and release of communication sessions. For example, SMF 325 can configure the traffic steering policy at UPF 345, or implement UE Internet Protocol (IP) address allocation and policy, etc. AMF 320 and SMF 325 can act as termination points for non-access layer (NAS) signaling or mobility management, etc. SMF 325 can act as a termination point for session management related to NAS. PCF 330 can provide a policy framework that incorporates network slicing, roaming, packet processing, or mobility management, etc.

[0054] The UPF 345 may serve as an anchor point for intra-RAT / inter-RAT mobility. The UPF 345 may apply rules to packets, such as those related to packet routing, traffic reporting, or handling user plane quality of service (QoS). The UPF 345 may determine the attributes of application-specific data communicated in a communication session. The UPF 345 may receive information (e.g., information identifying communication attributes of an application) from the RAN 310.

[0055] The BMCF 340 may provide broadcast / multicast area control, broadcast / multicast admission control, or SMF selection (e.g., session control via SMF selection), etc. The BMCF 340 may include a BMCPF that provides broadcast / multicast retransmission management. For example, the BMCPF may handle NACK feedback for broadcast / multicast communications. In some aspects, the core network 305 may not include the BMCF 340, and the functions of the BMCF 340 (as described above) may be performed by the AMF 320. For example, the AMF 320 may include the BMCPF.

[0056] BMF 350 may provide broadcast / multicast session management. For example, BMF 350 may provide management of content delivery sessions (such as file delivery over unidirectional transport (FLUTE) sessions). In some aspects, data network 315 may be connected to core network 305 via BMF 350. For example, a content server (such as a FLUTE server) may be connected to core network 305 via BMF 350. BMF 350 may be in communication with SMF 325 via interface 355. Interface 355 may be a control plane interface that enables session management or mobility management, etc., by BMF 350. BMF 350 may be in communication with UPF 345 via interface 360. Interface 360 ​​may be a user plane interface that enables data transmission (e.g., broadcast / multicast or unicast data transmission) by BMF 350.

[0057] Figure 4 is a diagram illustrating an example of mixed mode broadcast / multicast communication in accordance with various aspects of the present disclosure. Figure 4 The example can be combined with the above Figure 3 The core network 305, RAN 310 and data network 315 are described. Figure 4 As shown in FIG. 1 , UE 120 may communicate with various functions of core network 305 via RAN 310. These functions of core network 305 may be implemented by one or more devices (e.g., servers). For example, UE 120 may communicate with BMCF device 405 implementing BMCF 340, AMF device 410 implementing AMF 320, SMF device 415 implementing SMF 325, UPF device 420 implementing UPF 345, and BMF device 425 implementing BMF 350. One or more of BMCF device 405, AMF device 410, SMF device 415, UPF device 420, or BMF device 425 may be the same device (e.g., server) or different devices.

[0058] like Figure 4 As shown in , UE 120 may communicate with data network 315 via RAN 310 and core network 305. In some aspects, data network 315 may include content server 430, which provides data (e.g., video data) for broadcast / multicast transmission. Figure 4 As shown in , the content server 430 can be a FLUTE server that uses the FLUTE protocol on an asynchronous layer coding (ALC) protocol stack, and the ALC protocol stack includes a layered coding transmission (LCT) protocol, a wave and equation based rate control (WEBRC) protocol, and a FEC protocol. In some aspects, the content server 430 can be another type of content server. In some aspects, the content server 430 can be a device outside the RAN 310 or the core network 305 (for example, the content server 430 can be controlled by an entity other than the operator of the RAN 310 and the core network 305). For example, the content server 430 can be associated with a CDN, or can be a multi-access edge computing device at the edge of the RAN 310.

[0059] like Figure 4 As shown in , UE 120 may establish one or more communication sessions for receiving broadcast / multicast communications or unicast communications. For example, a broadcast / multicast session 435 or a unicast session 440 may be established between UE 120 and a UPF device 420, a BMCF device 405 or an AMF device 410 (e.g., one of the BMCF devices 405 or the AMF device 410 that is implementing BMCPF), and an SMF device 415 via RAN 310.

[0060] UE 120 may receive a schedule for broadcast / multicast communication and a broadcast / multicast communication according to the schedule in a broadcast / multicast session 435. For example, UE 120 may receive broadcast / multicast communication from UPF device 420 via RAN 310. Broadcast / multicast communication may include data originating from content server 430. In some aspects, broadcast / multicast communication may include one or more LCT layers (i.e., channels). For example, a first layer may be a lower quality version of broadcast / multicast communication (e.g., low resolution video), and a second layer may be a higher quality version of broadcast / multicast (e.g., high resolution video). In some aspects, broadcast / multicast communication may be encrypted according to a tunneling protocol (such as general packet radio service (GPRS) tunneling protocol (GTP)).

[0061] UE 120 may determine that a NACK feedback message for a broadcast / multicast communication will be transmitted. For example, UE 120 may determine that a NACK feedback message will be transmitted based at least in part on: determining that a broadcast / multicast communication was not received as expected, or determining that a broadcast / multicast communication or a portion thereof cannot be decoded. In some aspects, UE 120 may determine that a NACK feedback message will be transmitted for a specific LCT layer of a broadcast / multicast communication.

[0062] The UE 120 may transmit the NACK feedback message in the broadcast / multicast session 435 based at least in part on determining that a NACK feedback message for the broadcast / multicast communication (or a specific LCT layer of the broadcast / multicast communication) will be transmitted. For example, the UE 120 may transmit the NACK feedback message to the BMCPF device of the core network 305 via the RAN 310. The BMCPF device may correspond to the BMCF device 405 or the AMF device 410 (i.e., one of the BMCF device 405 or the AMF device 410 that implements the BMCPF function).

[0063] A BMCPF device (e.g., BMCF device 405) may use BMCPF to receive NACK feedback messages. Based at least in part on receiving the NACK feedback message, the BMCPF device using BMCPF may determine whether a retransmission of a broadcast / multicast communication to UE 120 will be a broadcast / multicast retransmission or a unicast retransmission. In some aspects, the BMCPF device may determine whether a retransmission will be a broadcast / multicast retransmission or a unicast retransmission based at least in part on the number of NACK feedback messages received from multiple UEs (including UE 120) within a specific time window. For example, the BMCPF device may determine that a retransmission will be a broadcast / multicast retransmission based at least in part on determining that the number of NACK feedback messages meets (e.g., is greater than) a threshold. Alternatively, the BMCPF device may determine that a retransmission will be a unicast retransmission based at least in part on determining that the number of NACK feedback messages does not meet (e.g., is less than) a threshold. The retransmission may be a repetition of a broadcast / multicast communication, or may be a broadcast / multicast communication with added redundancy (e.g., using FEC).

[0064] The BMCPF device using the BMCPF may cause retransmissions of the broadcast / multicast communication to be transmitted to the UE 120 via the RAN 310. For example, the BMCPF device may cause the UPF device 420 to transmit retransmissions of the broadcast / multicast communication via the RAN 310. The retransmissions may originate from the content server 430. For example, the BMCPF device may cause the BMF device 425 to obtain the retransmissions from the content server 430 (e.g., via a request) and provide the retransmissions to the UPF device 420 for transmission via the RAN 310. In other words, the content server 430 may transmit the retransmissions via the BMF device 425.

[0065] In some aspects, the BMCPF device may cause broadcast / multicast retransmissions to be transmitted in a broadcast / multicast session 435. In some other aspects, the BMCPF device may cause unicast retransmissions to be transmitted in a unicast session 440. In some aspects, the retransmissions may be encrypted according to a tunneling protocol, as described above.

[0066] UE 120 may receive retransmissions of broadcast / multicast communications via RAN 310. For example, UE 120 may receive retransmissions of broadcast / multicast communications based at least in part on transmitting a NACK feedback message. In this manner, performance of broadcast / multicast communications may be improved with greater efficiency.

[0067] In some aspects, the BMF device 425 may control one or more of the retransmission operations discussed above, rather than the BMCPF device. For example, the BMF device 425 may determine whether the retransmission will be a broadcast / multicast retransmission or a unicast retransmission, or may cause the UPF device 420 to transmit the retransmission. In some aspects, the content server 430 may receive a NACK feedback message from the UE 120 (e.g., to determine whether the retransmission will be a broadcast / multicast retransmission or a unicast retransmission). Based at least in part on receiving the NACK feedback message, the content server 430 may transmit a retransmission of the broadcast / multicast communication via the BMF device 435. In this way, the core network 305 may serve as a data conduit for the content server 430.

[0068] Figure 5 is a diagram illustrating an example functional architecture of a core network 505 according to various aspects of the present disclosure. In some aspects, the core network 505 may have an architecture that separates control plane and user plane functionality. Figure 5 As shown in FIG. 1 , the core network 505 may be in communication with the RAN 510 and the data network 515, as described above in conjunction with Figure 3 As described.

[0069] The core network 505 may include various types of core network architectures, such as a 5G NGN core included in a 5G wireless telecommunications system. In some aspects, the core network 505 may be implemented on a physical device or may be virtualized, as described above in conjunction with Figure 3 In some aspects, one or more devices implementing the core network 505 may be co-located with a base station (eg, BS 110).

[0070] like Figure 5 As shown in FIG. 5 , the core network 505 may include multiple functional elements. One or more of these functional elements of the core network 505 may be implemented on one or more devices (e.g., servers). These functional elements of the core network 505 may include a mobility management function (MMF) 520, a BMCPF 525, a PCF 530, an AF 535, a UPF 540, and a broadcast / multicast user plane function (BMUPF) 545. Figure 5 As shown in the figure, the RAN 510 can be connected to the core network 505 via the MMF 520, the UPF 540 or the BMUPF 545.

[0071] PCF 530, AF 535 and UPF 540 may correspond to the above combination Figure 3 PCF 330, AF 335, and UPF 345 are depicted. MMF 520 may provide mobility management and control plane termination at RAN 510.

[0072] BMCPF 525 may implement a broadcast / multicast control plane. For example, BMCPF 525 may provide broadcast / multicast retransmission management. As an example, BMCPF 525 may handle NACK feedback for broadcast / multicast communications. In addition, BMCPF 525 may perform broadcast / multicast security functions, provide broadcast / multicast service announcements, and perform broadcast / multicast session control.

[0073] The BMUPF 545 may implement a broadcast / multicast user plane controlled by the BMCPF 525 (i.e., a broadcast / multicast control plane). The BMUPF 545 may be in communication with the BMCPF 525 via an interface 550. The interface 550 may be a control plane interface that enables session management (e.g., FLUTE session management) by the BMUPF 545, among other things. In some aspects, the data network 515 may be connected to the core network 505 via the BMUPF 545, as described above in conjunction with Figure 3 In some aspects, the BMUPF 545 may have a bypassing UPF 540 ( Figure 5 ) a connection to the RAN 510 (indicated by a dotted line in FIG. 5 ).

[0074] Figure 6 is a diagram illustrating an example of mixed mode broadcast / multicast communication in accordance with various aspects of the present disclosure. Figure 6 The example can be combined with the above Figure 5 The core network 505, RAN 510 and data network 515 are described. Figure 6 As shown in , UE 120 can communicate with various functions of core network 505 via RAN 510. These functions of core network 505 can be implemented by one or more devices (e.g., servers). For example, UE 120 can communicate with MMF device 605 implementing MMF 520, BMCPF device 610 implementing BMCPF 525, UPF device 615 implementing UPF 540, and BMUPF device 620 implementing BMUPF 545. One or more of MMF device 605, BMCPF device 610, UPF device 615, or BMUPF device 620 can be the same device (e.g., server) or different devices.

[0075] like Figure 6 As shown in FIG. 1 , UE 120 may communicate with data network 515 via RAN 510 and core network 505. In some aspects, data network 515 may include content server 625, which may correspond to the content server 625 described above in conjunction with Figure 4 Content server 430 is described.

[0076] like Figure 6As shown in , UE 120 may establish one or more communication sessions for receiving broadcast / multicast communications or unicast communications. For example, a broadcast / multicast session 630 or a unicast session 635 may be between UE 120 and BMUPF device 620 via RAN 510. In other words, the broadcast / multicast session 630 or the unicast session 635 may bypass UPF device 615 ( Figure 6 indicated by dotted lines).

[0077] The UE 120 may receive a schedule for broadcast / multicast communications and broadcast / multicast communications according to the schedule in the broadcast / multicast session 435. For example, the UE 120 may receive the broadcast / multicast communications from the BMUPF device 620 via the RAN 510. The broadcast / multicast communications may include data originating from the content server 625. In some aspects, the broadcast / multicast communications may include one or more LCT layers, or may be encrypted according to a tunneling protocol, as described above in conjunction with Figure 4 As described.

[0078] UE 120 may determine that a NACK feedback message 640 for a broadcast / multicast communication will be transmitted, as described above in conjunction with Figure 4 The UE 120 may transmit a NACK feedback message 640 based at least in part on determining that a NACK feedback message 640 for a broadcast / multicast communication (or a specific LCT layer of a broadcast / multicast communication) will be transmitted. For example, the UE 120 may transmit the NACK feedback message 640 to the BMCPF device 610 via the RAN 510 (and via the MMF device 605).

[0079] The BMCPF device 610 may use the BMCPF to receive the NACK feedback message 640. Based at least in part on receiving the NACK feedback message 640, the BMCPF device 610 using the BMCPF may determine whether a retransmission of the broadcast / multicast communication to the UE 120 will be a broadcast / multicast retransmission or a unicast retransmission, as described above in conjunction with Figure 4 As described.

[0080] The BMCPF device 610 using the BMCPF may cause retransmissions of the broadcast / multicast communication to be transmitted to the UE 120 via the RAN 510. For example, the BMCPF device 610 may cause the BMUPF device 620 or the UPF device 615 to transmit retransmissions of the broadcast / multicast communication via the RAN 510. The retransmissions may originate from the content server 625. For example, the BMCPF device 610 may cause the BMUPF device 620 to obtain (e.g., via a request) a retransmission from the content server 625 for transmission via the RAN 310. In other words, the content server 625 may transmit the retransmission via the BMUPF device 620.

[0081] In some aspects, the BMCPF device 610 may cause the broadcast / multicast retransmissions to be transmitted by the BMUPF device 620 in a broadcast / multicast session 630. In some other aspects, the BMCPF device 610 may cause the unicast retransmissions to be transmitted by the BMUPF device 620 in a unicast session 635. In some further aspects, the BMCPF device 610 may cause the unicast retransmissions to be transmitted by the UPF device 615 in a unicast session between the UE 120 and the UPF device 615. In some aspects, the retransmissions may be encrypted according to a tunneling protocol, as described above.

[0082] UE 120 may receive retransmissions of broadcast / multicast communications via RAN 510. For example, UE 120 may receive retransmissions of broadcast / multicast communications based at least in part on transmitting NACK feedback message 640. In this manner, performance of broadcast / multicast communications may be improved with greater efficiency.

[0083] In some aspects, the BMUPF device 620 may control one or more of the retransmission operations discussed above, rather than the BMCPF device 610, as described above in conjunction with Figure 4 In some aspects, the content server 625 may receive a NACK feedback message 640 from the UE 120, as described above in conjunction with Figure 4 As described.

[0084] Figure 7 is a diagram illustrating an example process 700 of mixed mode broadcast / multicast communication performed, for example, by a UE in accordance with various aspects of the present disclosure. Example process 700 is an example in which a UE, such as UE 120, performs operations associated with mixed mode broadcast / multicast communication.

[0085] like Figure 7 As shown in , in some aspects, process 700 may include determining that a NACK feedback message for a broadcast / multicast communication will be transmitted (block 710). For example, the UE (using the controller / processor 280, etc.) may determine that a NACK feedback message for a broadcast / multicast communication will be transmitted, as described above.

[0086] like Figure 7 As further shown in FIG. 7 , in some aspects, process 700 may include transmitting a NACK feedback message to a BMCPF device of a core network via the RAN based at least in part on determining that a NACK feedback message will be transmitted (block 720). For example, the UE (using the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the MOD 254, the antenna 252, etc.) may transmit the NACK feedback message to the BMCPF device of the core network via the RAN based at least in part on determining that a NACK feedback message will be transmitted, as described above.

[0087] like Figure 7 As further shown in FIG. 7 , in some aspects, process 700 may include receiving a retransmission of a broadcast / multicast communication based at least in part on transmitting the NACK feedback message (block 730). For example, the UE (using antenna 252, DEMOD 254, MIMO detector 256, receive processor 258, controller / processor 280, etc.) may receive a retransmission of a broadcast / multicast communication based at least in part on transmitting the NACK feedback message, as described above.

[0088] Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes described elsewhere herein.

[0089] In a first aspect, the retransmission is based at least in part on the number of NACK feedback messages for the broadcast / multicast communication transmitted by multiple UEs including the UE satisfying a threshold and being a broadcast / multicast retransmission. In a second additional aspect, alone or in combination with the first aspect, the retransmission is based at least in part on the number of NACK feedback messages for the broadcast / multicast communication transmitted by multiple UEs including the UE not satisfying a threshold and being a unicast retransmission.

[0090] In a third additional aspect, alone or in combination with one or more of the first and second aspects, the retransmission is received from a UPF device of the core network via the RAN. In a fourth additional aspect, alone or in combination with one or more of the first to third aspects, the UPF device communicates with a BMF device of the core network via a user plane interface, and the BMF device communicates with an SMF device of the core network via a control plane interface, and communicates with a content server outside the core network. In a fifth additional aspect, alone or in combination with one or more of the first to fourth aspects, the BMCPF device is a BMCF device or an AMF device of the core network.

[0091] In a sixth additional aspect, alone or in combination with one or more of the first to fifth aspects, the retransmission is received from a BMUPF device of the core network via the RAN. In a seventh additional aspect, alone or in combination with one or more of the first to sixth aspects, the BMUPF device communicates with the BMCPF device via a control plane interface and communicates with a content server external to the core network. In an eighth additional aspect, alone or in combination with one or more of the first to seventh aspects, the BMCPF device communicates with an MMF device providing a control plane termination at the RAN.

[0092] In a ninth additional aspect, either alone or in combination with one or more of the first to eighth aspects, the retransmission is from a content server external to the core network. In a tenth aspect, either alone or in combination with one or more of the first to ninth aspects, the broadcast / multicast communication is encrypted according to a tunneling protocol. In an eleventh additional aspect, either alone or in combination with one or more of the first to tenth aspects, the broadcast / multicast communication includes one or more LCT layers, and the NACK feedback message is associated with a specific layer of these LCT layers.

[0093] Figure 8 8 is a diagram illustrating an example process 800 of a hybrid mode broadcast / multicast communication performed, for example, by a device of a core network according to various aspects of the present disclosure. The example process 800 is an example in which the device (such as BS 100, BMCF device 405, AMF device 410, or BMCPF device 610) performs operations associated with hybrid mode broadcast / multicast communication.

[0094] like Figure 8 As shown in , in some aspects, process 800 may include using the BMCPF to receive a NACK feedback message for a broadcast / multicast communication transmitted to the UE (block 810). For example, the device (using antenna 234, DEMOD 232, MIMO detector 236, receive processor 238, controller / processor 240, etc.) may use the BMCPF to receive a NACK feedback message for a broadcast / multicast communication transmitted to the UE, as described above.

[0095] like Figure 8 As further shown in FIG. 8 , in some aspects, process 800 may include causing a retransmission of a broadcast / multicast communication based at least in part on receiving a NACK feedback message (block 820). For example, the device (using controller / processor 240, transmit processor 220, TX MIMO processor 230, MOD 232, antenna 234, etc.) may cause a retransmission of a broadcast / multicast communication based at least in part on receiving a NACK feedback message, as described above.

[0096] Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below or in combination with one or more other processes described elsewhere herein.

[0097] In a first aspect, the retransmission is based at least in part on determining that the number of NACK feedback messages for the broadcast / multicast communication received from multiple UEs including the UE meets a threshold and is a broadcast / multicast retransmission. In a second additional aspect, alone or in combination with the first aspect, the retransmission is based at least in part on determining that the number of NACK feedback messages for the broadcast / multicast communication received from multiple UEs including the UE does not meet a threshold and is a unicast retransmission.

[0098] In a third additional aspect, alone or in combination with one or more of the first and second aspects, the retransmission is caused so that the UPF device of the core network transmits the retransmission. In a fourth additional aspect, alone or in combination with one or more of the first to third aspects, the UPF device communicates with the BMF device of the core network via a user plane interface, and the BMF device communicates with the SMF device of the core network via a control plane interface, and communicates with a content server outside the core network. In a fifth additional aspect, alone or in combination with one or more of the first to fourth aspects, the device is a BMCF device or an AMF device of the core network.

[0099] In a sixth additional aspect, alone or in combination with one or more of the first to fifth aspects, the retransmission is caused to cause a BMUPF device of the core network to transmit the retransmission. In a seventh additional aspect, alone or in combination with one or more of the first to sixth aspects, the BMUPF device communicates with the BMCPF of the device via a control plane interface and communicates with a content server external to the core network. In an eighth additional aspect, alone or in combination with one or more of the first to seventh aspects, the BMCPF of the device communicates with an MMF device that provides a control plane termination at the RAN.

[0100] In a ninth additional aspect, either alone or in combination with one or more of the first to eighth aspects, the retransmission is from a content server external to the core network. In a tenth aspect, either alone or in combination with one or more of the first to ninth aspects, the broadcast / multicast communication is encrypted according to a tunneling protocol. In an eleventh additional aspect, either alone or in combination with one or more of the first to tenth aspects, the broadcast / multicast communication includes one or more LCT layers, and the NACK feedback message is associated with a specific layer of these LCT layers.

[0101] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired by practice of the various aspects.

[0102] As used herein, the term "component" is intended to be broadly interpreted as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented with hardware, firmware, or a combination of hardware and software.

[0103] Some aspects are described herein in conjunction with a threshold. As used herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, or not equal to a threshold, etc., or a combination thereof.

[0104] It will be apparent that the systems or methods described herein can be implemented in different forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems or methods does not limit the various aspects. Thus, the operation and behavior of these systems or methods are described herein without reference to specific software codes-it is understood that software and hardware can be designed to implement these systems or methods based at least in part on the description herein.

[0105] Although particular combinations of features are recited in the claims or disclosed in the specification, these combinations are not intended to limit the disclosure of the various aspects. In fact, many of these features can be combined in ways not specifically recited in the claims or disclosed in the specification. Although each of the dependent claims listed below may be directly dependent on only one claim, the disclosure of the various aspects includes each dependent claim combined with every other claim in the set of claims.

[0106] As used herein, unless explicitly indicated otherwise, "or" is intended to be interpreted in an inclusive sense. For example, "a or b" may include only a, only b, or a combination of a and b. As used herein, a phrase that refers to "at least one of" or "one or more of" a list of items refers to any combination of those items, including individual members. For example, "at least one of a, b, or c" is intended to cover the following possibilities: only a, only b, only c, a combination of a and b, a combination of a and c, a combination of b and c, and a combination of a, b, and c.

[0107] Elements, actions or instructions used herein are not interpreted as critical or necessary unless explicitly described as such. Moreover, as used herein, the articles "one" and "a" are intended to include one or more items, and can be used interchangeably with "one or more". In addition, as used herein, the terms "set (set)" and "group" are intended to include one or more items (e.g., a combination of related items, non-related items, or related items and non-related items), and can be used interchangeably with "one or more". In the case of intending to have only one item, the phrase "only one" or similar language is used. Moreover, as used herein, the terms "have", "contain", "include", etc. or their combinations are intended to be open terms. In addition, the phrase "based on" is intended to mean "based at least in part on", unless otherwise explicitly stated.

Claims

1. A wireless communication method performed by a user equipment UE, comprising: Determining that a negative acknowledgement (NACK) feedback message for broadcast / multicast communication will be transmitted; transmitting the NACK feedback message to a broadcast / multicast control plane function device of a core network via a radio access network RAN ​​based at least in part on determining that the NACK feedback message is to be transmitted; as well as A unicast retransmission of the broadcast / multicast communication is received based at least in part on transmitting the NACK feedback message.

2. The method of claim 1, wherein the unicast retransmission is based at least in part on a number of NACK feedback messages for the broadcast / multicast communication transmitted by a plurality of UEs including the UE not satisfying a threshold.

3. The method of claim 1, wherein the unicast retransmission is received from a user plane function (UPF) device of the core network via the RAN.

4. The method of claim 3, wherein the UPF device communicates with a broadcast / multicast function device of the core network via a user plane interface, and wherein the broadcast / multicast function device communicates with a session management function device of the core network via a control plane interface, and communicates with a content server outside the core network. 5 . The method according to claim 1 , wherein the broadcast / multicast control plane function device is a broadcast / multicast coordination function device or an access and mobility management function device of the core network.

6. The method of claim 1, wherein the unicast retransmission is received from a broadcast / multicast user plane function device of the core network via the RAN.

7. The method of claim 6, wherein the broadcast / multicast user plane function device communicates with the broadcast / multicast control plane function device via a control plane interface and communicates with a content server outside the core network.

8. The method of claim 1, wherein the broadcast / multicast control plane function device communicates with a mobility management function device that provides control plane termination at the RAN.

9. The method of claim 1, wherein the unicast retransmission is from a content server external to the core network.

10. The method of claim 1, wherein the broadcast / multicast communication is encrypted according to a tunneling protocol.

11. The method of claim 1, wherein the broadcast / multicast communication comprises one or more layered coding transport (LCT) layers, and the NACK feedback message is associated with a specific layer in the LCT layers.

12. A wireless communication method performed by a core network device, comprising: receiving, using a broadcast / multicast control plane function, a negative acknowledgement (NACK) feedback message for a broadcast / multicast communication transmitted to a user equipment (UE); as well as A unicast retransmission of the broadcast / multicast communication is caused based at least in part on receiving the NACK feedback message.

13. The method of claim 12, wherein the unicast retransmission is based at least in part on determining that a number of NACK feedback messages received from a plurality of UEs including the UE for the broadcast / multicast communication does not satisfy a threshold.

14. The method of claim 12, wherein causing the unicast retransmission causes a user plane function (UPF) device of the core network to transmit the unicast retransmission.

15. The method of claim 14, wherein the UPF device communicates with a broadcast / multicast function device of the core network via a user plane interface, and wherein the broadcast / multicast function device communicates with a session management function device of the core network via a control plane interface, and communicates with a content server outside the core network.

16. The method according to claim 12, wherein the device is a broadcast / multicast coordination function device or an access and mobility management function device of the core network.

17. The method of claim 12, wherein causing the unicast retransmission causes a broadcast / multicast user plane function device of the core network to transmit the unicast retransmission.

18. The method of claim 17, wherein the broadcast / multicast user plane function device communicates with the broadcast / multicast control plane function of the device via a control plane interface and communicates with a content server external to the core network.

19. The method of claim 12, wherein the broadcast / multicast control plane function of the device communicates with a mobility management function device providing control plane termination at a radio access network.

20. The method of claim 12, wherein the unicast retransmission is from a content server external to the core network.

21. The method of claim 12, wherein the broadcast / multicast communication is encrypted according to a tunneling protocol.

22. The method of claim 12, wherein the broadcast / multicast communication includes one or more layered coding transport (LCT) layers, and the NACK feedback message is related to a specific layer in the LCT layers.

23. A user equipment UE for wireless communication, comprising: Memory; as well as one or more processors operatively coupled to the memory, the memory and the one or more processors being configured to: Determining that a negative acknowledgement (NACK) feedback message for broadcast / multicast communication will be transmitted; transmitting the NACK feedback message to a broadcast / multicast control plane function device of a core network via a radio access network RAN ​​based at least in part on determining that the NACK feedback message is to be transmitted; as well as A unicast retransmission of the broadcast / multicast communication is received based at least in part on transmitting the NACK feedback message.

24. The UE of claim 23, wherein the unicast retransmission is based at least in part on a number of NACK feedback messages for the broadcast / multicast communication transmitted by a plurality of UEs including the UE not satisfying a threshold.

25. The UE of claim 23, wherein the unicast retransmission is received from a user plane function (UPF) device of the core network via the RAN.

26. The UE as claimed in claim 25, wherein the UPF device communicates with the broadcast / multicast function device of the core network via a user plane interface, and wherein the broadcast / multicast function device communicates with the session management function device of the core network via a control plane interface, and communicates with a content server outside the core network.

27. The UE according to claim 23, wherein the broadcast / multicast control plane function device is a broadcast / multicast coordination function device or an access and mobility management function device of the core network.

28. The UE of claim 23, wherein the unicast retransmission is received from a broadcast / multicast user plane function device of the core network via the RAN.

29. The UE of claim 28, wherein the broadcast / multicast user plane function device communicates with the broadcast / multicast control plane function device via a control plane interface and communicates with a content server outside the core network.

30. The UE of claim 23, wherein the broadcast / multicast control plane function device communicates with a mobility management function device that provides control plane termination at the RAN.

31. The UE of claim 23, wherein the unicast retransmission is from a content server external to the core network.

32. The UE of claim 23, wherein the broadcast / multicast communication is encrypted according to a tunneling protocol.

33. The UE of claim 23, wherein the broadcast / multicast communication includes one or more layered coding transport (LCT) layers, and the NACK feedback message is related to a specific layer in the LCT layers.

34. A core network device for wireless communication, comprising: Memory; as well as one or more processors operatively coupled to the memory, the memory and the one or more processors being configured to: receiving, using a broadcast / multicast control plane function, a negative acknowledgement (NACK) feedback message for a broadcast / multicast communication transmitted to a user equipment (UE); and A unicast retransmission of the broadcast / multicast communication is caused based at least in part on receiving the NACK feedback message.

35. The apparatus of claim 34, wherein the unicast retransmission is based at least in part on determining that a number of NACK feedback messages received from a plurality of UEs including the UE for the broadcast / multicast communication does not satisfy a threshold.

36. The apparatus of claim 34, wherein causing the unicast retransmission causes a user plane function (UPF) device of the core network to transmit the unicast retransmission.

37. The device of claim 36, wherein the UPF device communicates with a broadcast / multicast function device of the core network via a user plane interface, and wherein the broadcast / multicast function device communicates with a session management function device of the core network via a control plane interface, and communicates with a content server outside the core network.

38. The device according to claim 34, wherein the device is a broadcast / multicast coordination function device or an access and mobility management function device of the core network.

39. The apparatus of claim 34, wherein causing the unicast retransmission causes a broadcast / multicast user plane function device of the core network to transmit the unicast retransmission.

40. The apparatus of claim 39, wherein the broadcast / multicast user plane function device communicates with the broadcast / multicast control plane function of the apparatus via a control plane interface and communicates with a content server external to the core network.

41. The apparatus of claim 34, wherein the broadcast / multicast control plane function of the apparatus is in communication with a mobility management function device providing control plane termination at a radio access network.

42. The apparatus of claim 34, wherein the unicast retransmission is from a content server external to the core network.

43. The apparatus of claim 34, wherein the broadcast / multicast communications are encrypted according to a tunneling protocol.

44. The apparatus of claim 34, wherein the broadcast / multicast communication comprises one or more layered coding transport (LCT) layers, and the NACK feedback message is associated with a specific layer in the LCT layers.

45. A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising: One or more instructions that, when executed by one or more processors of a user equipment UE, cause the one or more processors to: Determining that a negative acknowledgement (NACK) feedback message for broadcast / multicast communication will be transmitted; transmitting the NACK feedback message to a broadcast / multicast control plane function device of a core network via a radio access network RAN ​​based at least in part on determining that the NACK feedback message is to be transmitted; as well as A unicast retransmission of the broadcast / multicast communication is received based at least in part on transmitting the NACK feedback message.

46. ​​A non-transitory computer-readable medium storing one or more instructions for wireless communication, the one or more instructions comprising: One or more instructions that, when executed by one or more processors of a device of a core network, cause the one or more processors to perform the following operations: receiving, using a broadcast / multicast control plane function, a negative acknowledgement (NACK) feedback message for a broadcast / multicast communication transmitted to a user equipment (UE); and A unicast retransmission of the broadcast / multicast communication is caused based at least in part on receiving the NACK feedback message.

47. An apparatus for wireless communication, comprising: means for determining that a negative acknowledgement (NACK) feedback message for a broadcast / multicast communication will be transmitted; means for transmitting the NACK feedback message to a broadcast / multicast control plane function device of a core network via a radio access network RAN ​​based at least in part on determining that the NACK feedback message is to be transmitted; as well as Means for receiving a unicast retransmission of the broadcast / multicast communication based at least in part on transmitting the NACK feedback message.

48. An apparatus for wireless communication, comprising: means for receiving, using a broadcast / multicast control plane function, a negative acknowledgement (NACK) feedback message for a broadcast / multicast communication transmitted to a user equipment (UE); as well as Means for causing a unicast retransmission of the broadcast / multicast communication based at least in part on receiving the NACK feedback message.

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