Radio link control forward compatibility for multicast or broadcast messages

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) can receive, from a base station, a multicast message or a broadcast message using a radio link control (RLC) format associated with a RLC acknowledged mode (RLC-AM). The UE can decode the multicast message or the broadcast message to identify information associated with a RLC unacknowledged mode (RLC-UM) based at least in part on a capability of the UE. The UE can operate in accordance with the RLC-UM based at least in part on decoding the multicast message or the broadcast message. Numerous other aspects are provided.

Description

[0001] Cross-reference of related applications

[0002] This patent application claims priority to U.S. nonprovisional patent application No. 17 / 302,257, filed April 28, 2021, entitled “RADIO LINK CONTROL FORWARD COMPATIBILITY FOR MULTICAST MESSAGES OR BROADCAST MESSAGES”, which is hereby expressly incorporated by reference.

[0003] open field

[0004] Various aspects of this disclosure generally relate to wireless communications, and to techniques and apparatus for radio link control (RLC) forward compatibility for multicast or broadcast messages. Background Technology

[0005] Wireless communication systems are widely deployed to provide a variety of telecommunications services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth or transmit power). 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 an enhancement set of the Universal Mobile Telecommunications System (UMTS) mobile standard issued by the 3rd Generation Partnership Project (3GPP).

[0006] The multiple access technologies described above have been adopted in various telecommunications standards to provide a common protocol enabling different user equipment (UEs) to communicate at the city, country, region, and even global levels. New Radio (NR) (also known as 5G) is a set of enhancements to the LTE mobile standard issued by 3GPP. NR is designed to better support mobile broadband Internet access by using Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) (CP-OFDM) on the downlink (DL), using CP-OFDM or SC-FDMA (e.g., also known as Discrete Fourier Transform Extended OFDM (DFT-s-OFDM)) on the uplink (UL), and supporting beamforming, multiple-input multiple-output (MIMO) antenna technologies and carrier aggregation to improve spectral efficiency, reduce costs, improve service, utilize new spectrum, and better integrate with other open standards. However, with the continued growth in demand for mobile broadband access, there is a need for further improvements to LTE and NR technologies. Preferably, these improvements are applicable to other multiple access technologies and telecommunications standards that employ these technologies.

[0007] In some scenarios, a wireless network may support broadcast communication (where communication is provided to all UEs in the cell) or multicast communication (where communication is provided to a group of UEs). Broadcast or multicast (broadcast / multicast) communication can be used for the widespread dissemination of information, such as emergency alerts, audio content, or video content. In some scenarios, UEs in a wireless network or UEs in a cell may have different capabilities for multicast messages or broadcast messages (referred to herein as "multicast / broadcast messages"). For example, for a set of UEs in a cell, a first subset of UEs(one or more) may support the features of multicast / broadcast messages, and a second subset of UEs(one or more) may not support the features of multicast / broadcast messages.

[0008] Multicast and broadcast services introduce additional complexity associated with ensuring forward compatibility of UEs operating in a wireless network. For example, a base station may transmit multicast or broadcast data streams associated with a feature or feature enhancement (such as a feature or feature enhancement introduced in a version of a wireless communication standard). However, some UEs receiving the multicast or broadcast data stream may not support that feature or enhancement and may not be able to receive or decode the multicast or broadcast data stream at all (e.g., even if the associated feature or enhancement is ignored). Therefore, the base station may need to transmit multiple multicast or broadcast data streams associated with the same content to ensure that all UEs in the network can receive and decode multicast or broadcast messages. This adds additional complexity and signaling overhead associated with ensuring that UEs with different capabilities can receive multicast / broadcast messages.

[0009] Overview

[0010] Some aspects described herein provide a user equipment (UE) for wireless communication, the UE including at least one processor and at least one memory communicatively coupled to the at least one processor and storing processor-readable code. In some aspects, the processor-readable code, when executed by the at least one processor, is configured to cause the UE to receive from a base station a multicast message or broadcast message using a Radio Link Control (RLC) format associated with an RLC Acknowledgment Mode (RLC-AM). In some aspects, the processor-readable code, when executed by the at least one processor, is configured to cause the UE to decode the multicast message or broadcast message, at least in part, based on the UE's capabilities, to identify information associated with an RLC Unacknowledgment Mode (RLC-UM). In some aspects, the processor-readable code, when executed by the at least one processor, is configured to cause the UE to operate according to the RLC-UM, at least in part, based on decoding the multicast message or broadcast message.

[0011] Some aspects described herein provide a wireless communication method performed by a UE. The method may include receiving from a base station a multicast message or broadcast message using an RLC format associated with RLC-AM. The method may include decoding the multicast message or broadcast message to identify information associated with RLC-UM, based at least in part on the capabilities of the UE. The method may include operating according to the RLC-UM, based at least in part on decoding the multicast message or broadcast message.

[0012] Some aspects described herein provide a non-transient computer-readable medium for storing a set of instructions for wireless communication. The instruction set may include one or more instructions that, when executed by one or more processors of a UE, cause the UE to receive from a base station a multicast message or broadcast message using an RLC format associated with RLC-AM. In some aspects, the one or more instructions, when executed by one or more processors of the UE, cause the UE to decode the multicast message or broadcast message, at least in part, based on the UE's capabilities, to identify information associated with RLC-UM. In some aspects, the one or more instructions, when executed by one or more processors of the UE, cause the UE to operate according to RLC-UM, at least in part, based on decoding the multicast message or broadcast message.

[0013] Some aspects described herein provide an apparatus for wireless communication. The apparatus may include means for receiving from a base station a multicast message or broadcast message using an RLC format associated with RLC-AM. The apparatus may include means for decoding the multicast message or broadcast message, at least in part based on the apparatus's capabilities, to identify information associated with RLC-UM. The apparatus may include means for operating according to RLC-UM, at least in part based on decoding the multicast message or broadcast message.

[0014] Some aspects described herein provide a base station for wireless communication, the base station including at least one processor and at least one memory communicatively coupled to the at least one processor and storing processor-readable code. In some aspects, the processor-readable code, when executed by the at least one processor, is configured to cause the base station to generate a multicast message or a broadcast message using an RLC format associated with RLC-AM. In some aspects, the processor-readable code, when executed by the at least one processor, is configured to cause the base station to transmit the multicast message or the broadcast message using the RLC format associated with the RLC-AM, wherein transmitting the multicast message or broadcast message enables a first UE to operate according to the RLC-AM for the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM for the multicast or broadcast message.

[0015] Some aspects described herein provide a wireless communication method performed by a base station. The method may include generating a multicast message or a broadcast message using an RLC format associated with an RLC-AM. The method may include transmitting the multicast message or the broadcast message using the RLC format associated with the RLC-AM, wherein transmitting the multicast message or broadcast message enables a first UE to operate according to the RLC-AM used for the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM used for the multicast or broadcast message.

[0016] Some aspects described herein provide a non-transient computer-readable medium for storing a set of instructions for wireless communication. The instruction set may include one or more instructions that, when executed by one or more processors of a base station, cause the base station to generate a multicast message or a broadcast message using an RLC format associated with RLC-AM. In some aspects, the one or more instructions, when executed by one or more processors of the base station, cause the base station to transmit the multicast message or the broadcast message using the RLC format associated with the RLC-AM, wherein transmitting the multicast message or broadcast message enables a first UE to operate according to the RLC-AM used for the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM used for the multicast or broadcast message.

[0017] Some aspects described herein provide an apparatus for wireless communication. The apparatus may include means for generating multicast or broadcast messages using an RLC format associated with RLC-AM. The apparatus may include means for transmitting the multicast or broadcast message using the RLC format associated with the RLC-AM, wherein transmitting the multicast or broadcast message enables a first UE to operate according to the RLC-AM for the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM for the multicast or broadcast message.

[0018] The aspects generally include, as described substantially with reference to the accompanying drawings and description and explained as such, methods, apparatus, systems, computer program products, non-transient computer-readable media, user equipment, base stations, wireless communication equipment, or processing systems.

[0019] The foregoing has broadly outlined the features and technical advantages of the examples according to this disclosure in an effort to facilitate a better understanding of the following detailed description. Additional features and advantages will be described thereafter. The disclosed concepts and specific examples can be readily used as the basis for modifications or the design of other structures for implementing the same purposes as this disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, in both their organization and manner of operation, and their associated advantages, will be better understood by considering the following description in conjunction with the accompanying drawings. Each drawing is provided for illustrative and descriptive purposes and not for defining limitations on the claims. Brief description of the attached diagram

[0021] To gain a more detailed understanding of the features described above in this disclosure, reference can be made to various aspects of the above brief overview, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only some typical aspects of this disclosure and should not be considered as limiting its scope, as other equivalent aspects are permissible in this description. Identical reference numerals in different drawings may identify the same or similar elements.

[0022] Figure 1 This is a diagram illustrating an example of a wireless network according to this disclosure.

[0023] Figure 2 This is a diagram illustrating an example base station (BS) and user equipment (UE) communicating in a wireless network according to this disclosure.

[0024] Figure 3 This is a diagram illustrating the logical architecture of the distributed radio access network (RAN) according to this disclosure.

[0025] Figure 4This is a diagram illustrating an example of the user plane protocol stack and control plane protocol stack of a base station and core network used for communicating with a UE, according to this disclosure.

[0026] Figure 5 This is an illustration illustrating examples of the Packet Data Unit (PDU) formats for Radio Link Control (RLC) Unrecognized Mode (RLC-UM) and for RLC Recognized Mode (RLC-AM) according to this disclosure.

[0027] Figures 6A-6E This is a diagram illustrating an example of RLC forward compatibility related to multicast or broadcast messages according to this disclosure.

[0028] Figure 7 This is a flowchart illustrating an example procedure performed by a UE, for example, to support RLC forward compatibility for multicast or broadcast messages, according to this disclosure.

[0029] Figure 8 This is a flowchart illustrating an example process performed by a base station, according to this disclosure, to support RLC forward compatibility for multicast or broadcast messages.

[0030] Figure 9 and Figure 10 This is a block diagram of an example apparatus for wireless communication to support RLC forward compatibility for multicast or broadcast messages, according to the present disclosure.

[0031] Detailed description

[0032] The various aspects of this disclosure are described more fully below with reference to the accompanying drawings. However, this disclosure may be implemented in many different forms and is not to be construed as limited to any specific structure or function given throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Based on the teachings herein, those skilled in the art will appreciate that the scope of this disclosure is intended to cover any aspect of this disclosure disclosed herein, whether implemented independently of or in combination with any other aspect of this disclosure. For example, any number of aspects set forth herein may be used to implement an apparatus or method of practice. Furthermore, the scope of this disclosure is intended to cover such apparatus or methods practiced using additional structures, functionalities, or structures and functionalities that complement or supplement the various aspects of this disclosure set forth herein. Any aspect of this disclosure disclosed herein may be implemented by one or more elements of the claims.

[0033] Several aspects of a telecommunications system will now be described with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and explained in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, or algorithms (collectively, “elements”). These elements may be implemented using hardware, software, or a combination of hardware and software. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0034] The aspects generally involve Radio Link Control (RLC) forward compatibility for multicast or broadcast messages. Some aspects more specifically involve enabling a base station to transmit a single multicast or broadcast (multicast / broadcast) data stream that enables a first UE to operate according to an RLC Unacknowledged Mode (RLC-UM) for that single multicast / broadcast data stream and enables a second UE to operate according to an RLC Acknowledged Mode (RLC-AM) for that single multicast / broadcast data stream. In some aspects, a first UE that does not support RLC-AM procedures for multicast / broadcast messages may be able to decode multicast / broadcast messages using formats associated with RLC-AM. For example, when a multicast / broadcast message uses a format associated with RLC-AM, the first UE may identify and extract information associated with RLC-UM from the multicast / broadcast message. The first UE may use the information extracted from the multicast / broadcast message to operate according to RLC-UM. For example, the first UE can extract information associated with RLC-UM (such as segmentation information or sequence number) and can receive RLC packets from the base station based on RLC-UM (such as without providing feedback information that would otherwise be associated with RLC-AM).

[0035] In some respects, the first UE may identify, at least in part, that the format associated with RLC-AM is used for multicast / broadcast messages based on receiving a Radio Resource Control (RRC) configuration instructing the UE to use RLC-AM for the multicast / broadcast messages. The first UE may decode the multicast / broadcast messages using the format associated with RLC-AM, ignore the RRC configuration, and operate according to the RLC-UM used for multicast / broadcast messages using the format associated with RLC-AM.

[0036] In some other aspects, the base station may use a Packet Data Unit (PDU) format associated with a multicast or broadcast service (MBS) or a point-to-multipoint service (e.g., the MBS PDU format). The MBS PDU format may include one or more reserved bits or one or more other bits associated with RLC-AM. A first UE that does not support RLC-AM for multicast / broadcast messages may ignore one or more reserved bits or one or more other bits associated with RLC-AM and may be able to receive and decode multicast / broadcast messages using the MBS PDU format, enabling the first UE to operate according to RLC-AM for multicast / broadcast messages. Similarly, a second UE that supports RLC-AM for multicast / broadcast messages may identify and decode bits associated with RLC-AM, enabling the second UE to operate according to RLC-AM for the same multicast / broadcast messages using the MBS PDU format.

[0037] In some other aspects, the base station may be able to use reserved bits in the RLC header or the Packet Data Convergence Protocol (PDCP) PDU format, which indicates whether a packet is associated with a network decoding feature or a forward error correction feature, to indicate whether the packet is a parity packet or a redundant packet for network decoding or forward error correction features. In some other aspects, the base station may be able to use an RLC control PDU header, including a data or control (D / C) indication field and a control PDU type (CPT) field (where the CPT field indicates whether the packet is a parity packet or a redundant packet for network decoding or forward error correction features), to indicate whether a packet is associated with a network decoding feature or a forward error correction feature. Therefore, a UE that does not support network decoding or forward error correction features for multicast / broadcast messages can ignore or discard packets associated with network decoding or forward error correction features (because reserved bits or an unrecognized PDCP PDU format are used for the packet). Additionally, a UE that supports network decoding features or forward error correction features for multicast / broadcast messages can be able to identify packets associated with network decoding features or forward error correction features (e.g., based at least in part on information conveyed via reserved bits or PDCP PDU format). Therefore, the UE can receive or decode packets to enable the UE to operate according to the network decoding features or forward error correction features for multicast / broadcast messages.

[0038] Specific aspects of the subject matter described in this disclosure can be implemented to achieve one or more of the following potential advantages. In some examples, the described techniques can be used to enable a single multicast / broadcast message to support a first UE that does not support a feature or enhancement and a second UE that does support the feature or enhancement. For example, a single multicast / broadcast data stream can enable the first UE to operate according to RLC-UM for the single multicast / broadcast data stream, and can enable the second UE to operate according to RLC-AM for the single multicast / broadcast data stream. Additionally or alternatively, a single multicast / broadcast data stream can enable the first UE to discard parity packets or redundant packets while still receiving information included in the single multicast / broadcast data stream, and can enable the second UE to operate according to network decoding features or forward error correction features for the multicast / broadcast data stream. This saves the signaling overhead that would otherwise be required to transmit multiple multicast / broadcast messages to support a first UE that does not support a feature or enhancement and a second UE that does support the feature or enhancement within a cellular or wireless network. Furthermore, this reduces the complexity associated with ensuring forward compatibility of RLC features associated with multicast / broadcast messages.

[0039] Figure 1 This is a diagram illustrating an example of a wireless network according to this disclosure. The wireless network may be a 5G New Radio (NR) network or an LTE network, etc., or may include elements thereof. The wireless network may include one or more base stations 110 (shown as BS110a, BS110b, BS110c, and BS110d) and other network entities. A base station (BS) is an entity that communicates with a user equipment (UE) and may also be referred to as an NR BS, B-node, gNB, 5G B-node (NB), access point, or transmit / receive point (TRP), etc. Each BS may provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS or a BS subsystem serving that coverage area, depending on the context in which the term is used.

[0040] A BS can provide communication coverage for macrocells, picocells, femtocells, or another type of cell. Macrocells can cover a relatively large geographic area (e.g., a radius of several kilometers) and allow unrestricted access by UEs with a service subscription. Picocells can cover a relatively small geographic area and allow unrestricted access by UEs with a service subscription. Femtocells can cover a relatively small geographic area (e.g., a residential area) and allow restricted access by UEs associated with that femtocell (e.g., UEs in a Closed Subscriber Group (CSG)). A BS used for macrocells may be referred to as a macro BS. A BS used for picocells may be referred to as a pico BS. A BS used for femtocells may be referred to as a femto BS or a home BS. A BS may support one or more (e.g., three) cells.

[0041] Wireless networks can be heterogeneous networks comprising different types of Base Stations (BSs) (such as macro BSs, pico BSs, femto BSs, or relay BSs). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference within the wireless network. For example, macro BSs may have high transmit power levels (e.g., 5 to 40 watts), while pico BSs, femto BSs, and relay BSs may have lower transmit power levels (e.g., 0.1 to 2 watts). Figure 1 In the example shown, BS110a may be a macro BS for macro cell 102a, BS110b may be a pico BS for pico cell 102b, and BS110c may be a femto BS for femto cell 102c. Network controller 130 may be coupled to the BS set 102a, 102b, 110a, and 110b, and may provide coordination and control over these BSs. Network controller 130 may communicate with each BS via backhaul. These BSs may also communicate with each other directly or indirectly, for example, via wireless or wired backhaul.

[0042] In some respects, cells may not be stationary; instead, the geographical area of ​​a cell can move depending on the location of the mobile BS. In other respects, BSs can interconnect with each other or with one or more other BSs or network nodes (not shown) in a wireless network using any suitable transport network through various types of backhaul interfaces (such as direct physical connections or virtual networks).

[0043] The wireless network may also include relay stations. A relay station is an entity capable of receiving data transmissions from an upstream station (e.g., a BS or a UE) and transmitting those data transmissions to a downstream station (e.g., a UE or a BS). A relay station can also be a UE capable of relaying transmissions for other UEs. Figure 1In the example shown, relay BS110d can communicate with macro BS110a and UE 120d to facilitate communication between BS110a and UE 120d. A relay BS can also be referred to as a relay station, relay base station, or relay, etc.

[0044] UEs 120 (e.g., 120a, 120b, 120c) may be distributed throughout the wireless network, and each UE may be stationary or mobile. A UE may also be referred to as an access terminal, terminal, mobile station, subscriber unit, or station, etc. A UE may be a cellular phone (e.g., a smartphone), 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 (smartwatch, 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, industrial manufacturing equipment, a GPS device, or any other suitable device configured to communicate via a wireless medium.

[0045] Some UEs can be considered 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, which can communicate with a base station, another device (e.g., a remote device), or some other entity. Wireless nodes can provide connectivity to or to a network (e.g., a wide area network such as the Internet) or a cellular network, for example, via wired or wireless communication links. Some UEs can be considered Internet of Things (IoT) devices, or can be implemented as NB-IoT (Narrowband Internet of Things) devices. Some UEs can be considered Customer Premises Equipment (CPE). UE 120 can be included within a housing that houses the components of UE 120, such as processor components or memory components.

[0046] Generally, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific Radio Access Technology (RAT) and can operate on one or more frequencies or frequency channels. A frequency may also be referred to as a carrier, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between wireless networks using different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0047] In some respects, 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, vehicle-to-infrastructure (V2I) protocols), mesh networking, or combinations thereof. In such examples, UE 120 may perform scheduling operations, resource selection operations, or other operations described elsewhere herein as performed by base station 110.

[0048] Devices in a wireless network can communicate using the electromagnetic spectrum, which can be subdivided into various categories, bands, or channels based on frequency or wavelength. For example, devices in a wireless network can communicate using an operating band with a first frequency range (FR1) spanning from 410 MHz to 7.125 GHz. As another example, devices in a wireless network can communicate using an operating band with a second frequency range (FR2) spanning from 24.25 GHz to 52.6 GHz. The frequencies between FR1 and FR2 are sometimes referred to as intermediate frequency (IF) bands. Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to as the “sub-6 GHz” band. Similarly, FR2 is often referred to as the “millimeter wave” band, although it is different from the Very High Frequency (EHF) band (30 GHz–300 GHz) identified as the “millimeter wave” band by the International Telecommunication Union (ITU). Therefore, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” can broadly refer to frequencies less than 6 GHz, frequencies within FR1, intermediate frequency bands (e.g., greater than 7.125 GHz), or combinations thereof. Similarly, unless otherwise stated, it should be understood that the term "millimeter wave" can broadly refer to frequencies within the EHF band, frequencies within FR2, intermediate frequency band frequencies (e.g., less than 24.25 GHz), or combinations thereof. The frequencies included in FR1 and FR2 may be modified, and the techniques described herein are applicable to those modified frequency ranges.

[0049] In some aspects, UE 120 may include a communications manager 140. As described in more detail elsewhere herein, communications manager 140 may receive from a base station multicast or broadcast messages using a Radio Link Control (RLC) format associated with an RLC Acknowledgment Mode (RLC-AM); decode the multicast or broadcast messages, at least in part based on the UE's capabilities, to identify information associated with an RLC Unacknowledgment Mode (RLC-UM); and operate according to RLC-UM, at least in part based on the decoded multicast or broadcast messages. Additionally or alternatively, communications manager 140 may perform one or more other operations described herein.

[0050] In some aspects, base station 110 may include communication manager 150. As described in more detail elsewhere herein, communication manager 150 may generate multicast or broadcast messages using an RLC format associated with RLC Acknowledgment Mode (RLC-AM); and transmit multicast or broadcast messages using an RLC format associated with RLC-AM, wherein transmitting the multicast or broadcast message enables a first UE to operate according to RLC-AM for the multicast or broadcast message, and enables a second UE to operate according to RLC-UM for the multicast or broadcast message. Additionally or alternatively, communication manager 150 may perform one or more other operations described herein.

[0051] Figure 2 This is an illustration illustrating communication between an example base station and a UE in a wireless network according to this disclosure. The base station may correspond to... Figure 1 Base station 110. Similarly, the UE can correspond to Figure 1 UE 120.

[0052] Base station 110 may be equipped with T antennas 234a to 234t, and UE 120 may be equipped with R antennas 252a to 252r, where generally T ≥ 1 and R ≥ 1. At base station 110, transmit processor 220 may receive data destined for one or more UEs from data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on the Channel Quality Indicator (CQI) received from each UE, process (e.g., encode) the data destined for each UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. Transmit processor 220 may also process system information (e.g., semi-static resource allocation information (SRPI), etc.) and control information (e.g., CQI requests, grants, or upper-layer signaling), and provide overhead symbols and control symbols. Transmit processor 220 may also generate reference symbols for reference signals and synchronization signals. The transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, or reference symbols where applicable, and can provide T output symbol streams to T modulators (MODs) 232a to 232t. Each MOD 232 can process its corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each MOD 232 can 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 can be transmitted via T antennas 234a to 234t respectively.

[0053] At UE 120, antennas 252a to 252r can receive downlink signals from base station 110 or other base stations and can provide the received signals to R demodulators (DEMODs) 254a to 254r respectively. Each DEMOD 254 can condition (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain an input sample. Each DEMOD 254 can further process the input sample (e.g., for OFDM) to obtain received symbols. MIMO detector 256 can obtain the symbols received from all R DEMODs 254a to 254r, perform MIMO detection on these received symbols where applicable, and provide detected symbols. Receiver processor 258 can process (e.g., decode) these detected symbols, provide the decoded data for UE 120 to data sink 260, and provide the decoded control information and system information to controller / processor 280. The term "controller / processor" can refer to one or more controllers, one or more processors, or a combination of one or more controllers and one or more processors. The channel processor can determine one or more of the following parameters: Reference Signal Received Power (RSRP), Received Signal Strength Indicator (RSSI), Reference Signal Received Quality (RSRQ), or Channel Quality Indicator (CQI). In some respects, one or more components of the UE 120 may be included in a housing.

[0054] Network controller 130 may include communication unit 294, controller / processor 290, and memory 292. Network controller 130 may include one or more devices, such as those in a core network. Network controller 130 may communicate with base station 110 via communication unit 294.

[0055] Antennas (such as antennas 234a to 234t or antennas 252a to 252r) may include or be included within one or more antenna panels, antenna groups, antenna element assemblies, or antenna arrays. Antenna panels, antenna groups, antenna element assemblies, or antenna arrays may include one or more antenna elements. Antenna panels, antenna groups, antenna element assemblies, or antenna arrays may include coplanar antenna element assemblies or non-coplanar antenna element assemblies. Antenna panels, antenna groups, antenna element assemblies, or antenna arrays may include antenna elements within a single housing or antenna elements within multiple housings. Antenna panels, antenna groups, antenna element assemblies, or antenna arrays may include elements coupled to one or more transmitting or receiving components (such as...) Figure 2 One or more antenna elements (one or more components).

[0056] On the uplink, at UE 120, transmit processor 264 can receive and process data from data source 262 and control information from controller / processor 280 (e.g., reports including RSRP, RSSI, RSRQ, or CQI). Transmit processor 264 can also generate reference symbols for one or more reference signals. Symbols from transmit processor 264 may be pre-encoded by TX MIMO processor 266, where applicable, further processed by MODs 254a to 254r (e.g., for Discrete Fourier Transform Extended Orthogonal Frequency Division Multiplexing (DFT-s-OFDM), or Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) (CP-OFDM)), and transmitted to base station 110. In some aspects, modulators and demodulators of UE 120 (e.g., MOD / DEMOD 254) may be included in the modem of UE 120. In some aspects, UE 120 includes a transceiver. The transceiver may include any combination of antenna 252, modulator 254, demodulator 254, MIMO detector 256, receiver processor 258, transmitter processor 264, or TX MIMO processor 266. The transceiver may be used by a processor (e.g., controller / processor 280) and memory 282 to perform aspects of any of the methods described herein.

[0057] At base station 110, uplink signals from UE 120 and other UEs can be received by antenna 234, processed by DEMOD 232, detected by MIMO detector 236 where applicable, and further processed by receiver processor 238 to obtain decoded data and control information transmitted by UE 120. Receiver processor 238 can provide the decoded data to data sink 239 and the decoded control information to controller / processor 240. Base station 110 may include communication unit 244 and communicate with network controller 130 via communication unit 244. Base station 110 may include scheduler 246 to schedule downlink and uplink communications of UE 120. In some aspects, the modulator and demodulator (e.g., MOD / DEMOD 232) of base station 110 may be included in the modem of base station 110. In some aspects, base station 110 includes transceiver. The transceiver may include any combination of antenna 234, modulator 232, demodulator 232, MIMO detector 236, receiver processor 238, transmitter processor 220, or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller / processor 240) and memory 242 to perform aspects of any of the methods described herein.

[0058] The controller / processor 240 of base station 110, the controller / processor 280 of UE 120, or Figure 2 Any other component may perform one or more techniques associated with RLC forward compatibility for multicast or broadcast messages, as described in more detail elsewhere herein. For example, the controller / processor 240 of base station 110, the controller / processor 280 of UE 120, or... Figure 2 Any other component may execute or direct, for example Figure 7 Process 700 Figure 8 The operation of process 800 or other processes as described herein. Memory 242 and 282 may store data and program code of base station 110 and UE 120, respectively. In some aspects, memory 242 or memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code or program code) for wireless communication. For example, when executed by one or more processors of base station 110 or UE 120 (e.g., directly executed, or executed after compilation, transformation, or interpretation), the one or more processors, UE 120, or base station 110 may cause the one or more processors, UE 120, or base station 110 to perform or direct, for example... Figure 7 Process 700 Figure 8 The operation of process 800 or other processes as described herein. In some aspects, the execution instructions may include run instructions, translate instructions, compile instructions, or interpret instructions, etc.

[0059] In some aspects, UE 120 includes: means for receiving from a base station a multicast message or broadcast message using an RLC format associated with RLC-AM; means for decoding the multicast message or broadcast message to identify information associated with RLC-UM, at least in part based on the UE's capabilities; or means for operating according to RLC-UM, at least in part based on decoding the multicast message or broadcast message. Means for UE 120 to perform the operations described herein may include, for example, one or more of a communication manager 140, an antenna 252, a demodulator 254, a MIMO detector 256, a receive processor 258, a transmit processor 264, a TX MIMO processor 266, a modulator 254, a controller / processor 280, or a memory 282.

[0060] In some aspects, base station 110 includes means for generating multicast or broadcast messages using an RLC format associated with RLC-AM; or means for transmitting multicast or broadcast messages using an RLC format associated with RLC-AM, wherein transmitting the multicast or broadcast message enables a first UE to operate according to RLC-AM for the multicast or broadcast message, and enables a second UE to operate according to RLC-UM for the multicast or broadcast message. Means for base station 110 to perform the operations described herein may include, for example, one or more of a communication manager 150, a transmit processor 220, a TX MIMO processor 230, a modem 232, an antenna 234, a demodulator 232, a MIMO detector 236, a receive processor 238, a controller / processor 240, a memory 242, or a scheduler 246.

[0061] Figure 3 This is a diagram illustrating the logical architecture 300 of the distributed radio access network (RAN) according to this disclosure. One or more entities of the 5G network may have a multicast or broadcast user plane function (MB-UPF) 305 and an access and mobility function (AMF) 310. The MB-UPF 305 may have an N3 interface 315 for delivering packetized MB streams 320 (e.g., in the form of Protocol Data Units (PDUs)) to a 5G access node, such as a gNB or base station 110. The AMF 310 may use the N2 interface 325 with the gNB to control signaling for MB stream setting and modification.

[0062] The gNB may include a central unit (CU), shown as gNB-CU 330. The gNB may also include one or more distributed units (DUs), shown as DU1 335 and DU2 340. DU1 335 and DU2 340 may be configured to individually (e.g., via dynamic selection) or jointly (e.g., via joint transmission) serve traffic to the UE. As shown, DU1 335 may use a first multicast or broadcast radio bearer (MRB) (shown as MRB1 350) to serve traffic to a first UE or a first UE group 345, and DU2 340 may use a second MRB (shown as MRB2 360) to serve traffic to a second UE or a second UE group 355.

[0063] In some scenarios, the wireless network can support broadcast communication (where communication is provided to all UEs in the cell) or multicast communication (where communication is provided to a group of UEs). Broadcast or multicast (broadcast / multicast) communication can be used for the widespread dissemination of information, such as emergency alerts, audio content, or video content. Support for multicast or broadcast services is added to the NR. In the NR, UEs may be able to receive, for example, multicast or broadcast services in a hybrid mode or broadcast mode. Using hybrid mode, multicast or broadcast services can be delivered to UEs in the RRC connected state using an MRB or a dedicated radio bearer (DRB). Using broadcast mode, multicast broadcast services can be delivered to UEs in the RRC connected state, RRC idle state, or RRC inactive state using an MRB.

[0064] In some scenarios, UEs in a wireless network or a cellular network may have different capabilities for multicast or broadcast messages (referred to herein as "multicast / broadcast messages"). For example, for a set of UEs in a cellular network, a first subset of UEs may support features (or enhancements of features) for multicast / broadcast messages, while a second subset of UEs may not support such features. For example, wireless communication standards (such as 3GPP) may enable UEs to operate using one or more features for multicast / broadcast messages, depending on the version of that wireless communication standard. Future versions may add or enable additional features for multicast / broadcast messages for UEs. For example, a UE operating according to a first version (such as version 17) may not support one or more features, while a UE operating according to a second version (such as version 18) may support one or more features or enhancements of those features. For example, for multicast or broadcast in NR, a UE operating according to a first version of the wireless communication standard may not support Radio Link Control (RLC) Acknowledgment Mode (RLC-AM) for multicast / broadcast messages. A UE operating according to version 1 of the wireless communication standard may only support RLC Unacknowledged Mode (RLC-UM) for multicast / broadcast messages. However, a UE operating according to version 2 of the wireless communication standard may support both RLC-AM and RLC-UM for multicast / broadcast messages. As another example, a UE operating according to version 1 may not support forward error correction (or network decoding procedure) for multicast / broadcast messages, while a UE operating according to version 2 may support forward error correction for multicast / broadcast messages.

[0065] Multicast and broadcast services introduce additional complexity associated with ensuring forward compatibility of UEs operating in a wireless network. For example, a base station may transmit multicast or broadcast data streams associated with a feature. However, some UEs receiving multicast or broadcast data streams may not support that feature and may be unable to receive or decode them. Therefore, the base station may need to transmit multiple multicast or broadcast data streams to ensure that all UEs in the network can receive and decode multicast or broadcast messages. For example, the base station may need to use the RLC-AM format to transmit a first multicast / broadcast message to enable a first set of UEs to operate according to RLC-AM (for UEs that support RLC-AM for multicast / broadcast messages). Additionally, the base station may need to use the RLC-UM format to transmit a second multicast / broadcast message to enable a second set of UEs to operate according to RLC-UM (for UEs that do not support RLC-AM for multicast / broadcast messages). This adds additional complexity and signaling overhead associated with ensuring that UEs with different capabilities can receive multicast / broadcast messages.

[0066] Figure 4 This is a diagram illustrating an example of a user plane protocol stack 400 and a control plane protocol stack 410 of a base station 110 and a core network for communicating with a UE 120, according to this disclosure. On the user plane, the UE 120 and BS 110 may include corresponding physical (PHY) layers, media access control (MAC) layers, RLC layers, packet data convergence protocol (PDCP) layers, and service data adaptation protocol (SDAP) layers.

[0067] User plane functions handle the transmission of user data between UE 120 and BS110. On the control plane, UE 120 and BS110 may include corresponding RRC layers. Additionally, UE 120 may include a Non-Access Layer (NAS) layer communicating with the NAS layer of Access and Management Mobility Functions (AMF). AMF may be associated with the core network of BS110, such as a 5G core network (5GC) or a Next Generation Radio Access Network (NG-RAN). Control plane functions handle the transmission of control information between the UE and the core network. Generally, if the first layer is further away from the PHY layer than the second layer, the first layer is referred to as being above the second layer. For example, the PHY layer may be referred to as the lowest layer, and the SDAP, PDCP, RLC, and MAC layers may be referred to as being above the PHY layer and below the RRC layer. Application (APP) layer ( Figure 4 (Not shown in the text) can be above the SDAP, PDCP, RLC, and MAC layers. In some cases, an entity can handle the services and functions of a given layer (e.g., a PDCP entity can handle the services and functions of the PDCP layer), although the description herein refers to the layer itself that handles the services and functions.

[0068] The RRC layer handles communications related to configuring and operating UE 120, such as: broadcasting system information related to the Access Layer (AS) and NAS; paging initiated by 5GC or NG-RAN; establishing, maintaining, and releasing RRC connections between the UE and NG-RAN, including adding, modifying, and releasing carrier aggregation, as well as adding, modifying, and releasing dual connectivity; security functions including key management; establishing, configuring, maintaining, and releasing Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs); mobility functions (e.g., handover and context transfer, UE cell selection and reselection, and control of cell selection and reselection, inter-RAT mobility); Quality of Service (QoS) management functions; UE measurement reporting and reporting control; detection and recovery of radio link failures; and NAS message transmission between the UE 120's NAS layer and lower layers. The RRC layer is commonly referred to as Layer 3 (L3).

[0069] The SDAP, PDCP, RLC, and MAC layers can be collectively referred to as Layer 2 (L2). Therefore, in some cases, the SDAP, PDCP, RLC, and MAC layers are called sublayers of Layer 2. On the transport side (e.g., if UE 120 is transmitting uplink communication or BS110 is transmitting downlink communication), the SDAP layer can receive data streams in the form of QoS streams. A QoS stream is associated with a QoS identifier (which identifies the QoS parameters associated with the QoS stream) and a QoS stream identifier (which identifies the QoS stream). Policy and charging parameters are implemented at the QoS stream granularity. A QoS stream can include one or more Service Data Streams (SDFs), provided that each SDF of the QoS stream is associated with the same policy and charging parameters. In some examples, the RRC or NAS layer can generate control information to be transmitted and can map the control information to one or more radio bearers for provision to the PDCP layer.

[0070] The SDAP or RRC / NAS layer can map QoS flows or control information to radio bearers. Thus, the SDAP layer can be said to process QoS flows on the transport side. The SDAP layer can provide QoS flows to the PDCP layer via the corresponding radio bearer. The PDCP layer can map radio bearers to RLC channels. The PDCP layer can handle various services and functions on the user plane, including: sequence numbering, header compression and decompression (when robust header compression is enabled), transmission of user data, reordering and deduplication (where sequential delivery to layers above the PDCP layer is required), PDCP Protocol Data Unit (PDU) routing (in the case of split bearers), retransmission of PDCP Service Data Units (SDUs), cryptography and cryptographic decryption, PDCP SDU discarding (e.g., according to timers, as described elsewhere herein), PDCP reconstruction and data recovery for RLC AM, and PDCP PDU duplication. The PDCP layer can handle similar services and functions on the control plane, including sequence numbering, encryption, decryption, integrity protection, transmission of control plane data, deduplication, and PDCP PDU duplication.

[0071] The PDCP layer can provide data to the RLC layer in the form of PDCP PDUs via the RLC channel. The RLC layer can handle the transmission of upper-layer PDUs to the MAC or PHY layer, sequence numbering independent of PDCP sequence numbering, error correction via Automatic Repeat Request (ARQ), segmentation and resegmentation, SDU reassembly, RLC SDU discarding, and RLC reconstruction.

[0072] The RLC layer can provide data mapped to logical channels to the MAC layer. The services and functions of the MAC layer include: mapping between logical channels and transport channels (used by the PHY layer, as described below), multiplexing MAC SDUs belonging to one or different logical channels on the transport channel to transport blocks (TBs) passed to / from the physical layer, demultiplexing transport blocks passed from the physical layer, scheduling information reporting, error correction via Hybrid ARQ (HARQ), prioritization among UEs using dynamic scheduling, prioritization among logical channels of a UE using logical channel priority ordering, and padding.

[0073] The MAC layer can package data from logical channels into data blocks (TBs) and can provide TBs to the PHY layer on one or more transport channels. The PHY layer can handle various operations related to the transmission of data signals, such as... Figure 2 A more detailed description. The PHY layer is usually referred to as layer 1 (L1).

[0074] On the receiving side (e.g., if UE 120 is receiving downlink communication or BS110 is receiving uplink communication), the operation can be similar to, but reversed, the operation described for the transmitting side. For example, the PHY layer can receive the transport layer (TB) and can provide the TB to the MAC layer on one or more transport channels. The MAC layer can map the transport channels to logical channels and can provide data to the RLC layer via the logical channels. The RLC layer can map the logical channels to RLC channels and can provide data to the PDCP layer via the RLC channels. The PDCP layer can map the RLC channels to radio bearers and can provide data to the SDAP layer or RRC / NAS layer via the radio bearers.

[0075] Data can be transferred between layers in the form of PDUs and SDUs. An SDU is a data unit that has been passed from a layer or sublayer to a lower layer. For example, the PDCP layer can receive PDCP SDUs. A given layer can then encapsulate the data unit into a PDU and pass that PDU to a lower layer. For example, the PDCP layer can encapsulate a PDCP SDU into a PDCP PDU and pass a PDCP PDU to the RLC layer. The RLC layer can receive a PDCP PDU as an RLC SDU, encapsulate an RLC SDU into an RLC PDU, and so on. In effect, the PDU carries the SDU as a payload.

[0076] Figure 5 This is a diagram illustrating examples of PDU format 500 for RLC-UM and PDU format 510 for RLC-AM according to this disclosure. (See diagram for example.) Figure 5 As shown, RLC-UM and RLC-AM can use different PDU formats. For example, PDU format 500 for RLC-UM can depict the format for UM data (UMD) PDUs. PDU format 510 for RLC-AM can depict the format for AM data (AMD) PDUs. PDU formats 500 and 510 are provided as examples, and other examples are possible. For example, wireless communication standards (such as 3GPP specification 38.322) can define or otherwise fix one or more PDU formats for UM PDUs and one or more PDU formats for AMD PDUs.

[0077] In some scenarios, RLC can be associated with transparent mode, UM mode, or AM mode. In transparent mode, the PDU does not use an RLC header, buffering is performed only at the sending RLC entity, fragmentation or reassembly is not used, and the receiving RLC entity does not provide feedback (e.g., no ACK or NACK feedback). In UM mode, the PDU includes an RLC header, buffering is performed at both the sending and receiving RLC entities, fragmentation and reassembly can be used, and the receiving RLC entity does not provide feedback (e.g., no ACK or NACK feedback). In AM mode, the PDU includes an RLC header, buffering is performed at both the sending and receiving RLC entities, fragmentation and reassembly can be used, and the receiving RLC entity can provide feedback (e.g., the receiving RLC entity can provide ACK or NACK feedback).

[0078] For example, a UE 120 operating under RLC-UM may not provide a receive response (such as ACK or NACK feedback) in response to receiving a PDU. A UE 120 operating under RLC-AM may transmit a receive response (such as ACK or NACK feedback) in response to receiving a PDU. For example, RLC-AM may enable the UE 120 to transmit a status PDU indicating RLC control information, such as ACK or NACK feedback for one or more RLC SDUs. RLC-AM may enable the UE 120 to poll peer RLC entities to trigger a status report at the peer RLC entity. For example, the UE 120 may transmit a PDU indicating polling (using fields in the RLC header) of the receiving RLC entity. The receiving RLC entity may transmit a status PDU indicating RLC control information, such as ACK or NACK feedback, based on the received polling-indicating PDU. As described above, a UE 120 operating under RLC-UM may not perform a status reporting or polling procedure.

[0079] like Figure 5 As shown, the PDU format 500 for RLC-UM (e.g., for UMD PDU) may include two bits for segmentation information (SI) in the first octet (Oct 1). SI may indicate whether the PDU's data field contains all bytes of the RLC SDU (e.g., indicating no segmentation), whether the PDU's data field contains the first segment of the RLC SDU, whether the PDU's data field contains the last segment of the RLC SDU, or whether the PDU's data field contains neither the first nor the last segment of the RLC SDU. The PDU format 500 may include two reserved bits in the first octet (in... Figure 5(Illustrated as "R"). The last four bits of the first octet used for PDU format 500 can be associated with the sequence number (SN) used for the UMDPDU. For example... Figure 5 As shown, PDU format 500 can use a 12-bit SN in the UMD PDU, such that all bits of the second octet (Oct 2) are associated with the SN. The remaining octets (Oct 3 to Oct N) of PDU format 500 can be associated with data fields. In some cases, the PDU format for RLC-UM can include a field for the sequence number only when segmentation is used.

[0080] The PDU format 510 for RLC-AM (e.g., for AMD PDUs) may include an indication in the first octet (Oct 1) whether the PDU is for data or control information. Figure 5 The bit indicated as "D / C" in the diagram. This bit, which indicates whether the PDU is for data or control information, may be referred to herein as the "D / C bit" or "D / C indicator," etc. The PDU format 510 may include a polling bit in the first octet indicating whether polling is requested for the PDU. Figure 5 (Illustrated as "P"). PDU format 510 may include two bits for SI in the first octet. The last four bits of the first octet for PDU format 510 may be associated with SN for AMD PDU. Figure 5 As shown, PDU format 510 can use a 12-bit SN for the AMD PDU, such that all bits of the second octet (Oct 2) are associated with the SN. The remaining octets (Oct 3 to Oct N) of PDU format 510 can be associated with data fields. The AMD PDU can always use the SN (compared to the UMD PDU, which may not include the SN in some cases). Additionally, if segmentation is used, PDU format 510 can include one or more fields associated with a segment offset. The segment offset field can be used to indicate the location of the AMD PDU segment, in bytes, within the original RLC SDU.

[0081] Therefore, as Figure 5As shown, the formats used for RLC-AM and RLC-UM can differ to support different features of RLC-AM and RLC-UM. For example, PDU format 510 for RLC-AM may include bits indicating whether the AMD is for data or control information, as well as polling bits, while PDU format 500 for RLC-UM may not include bits indicating whether the AMD is for data or control information, as well as polling bits (because this information is irrelevant to RLC-UM). Similarly, if segmentation is used, PDU format 510 for RLC-AM may include one or more fields associated with segment offsets. Conversely, if segmentation is not used, PDU format 500 for RLC-UM may not include fields associated with segment offsets. Furthermore, although both PDU format 500 and PDU format 510 include fields associated with SI, the positions of the SI fields within PDU format 500 and PDU format 510 are different. Therefore, a UE 120 that is not enabled or configured to operate in RLC-AM may not be able to decode or recognize PDUs using PDU format 510 (or another PDU format for RLC-AM).

[0082] In some cases, if UE 120 receives a PDU format that uses unknown or reserved fields (e.g., where the unknown or reserved fields include the value "1"), UE 120 may discard or ignore the PDU (e.g., according to wireless communication standards). Therefore, UE 120 that does not support RLC-AM may be unable to receive messages using PDU format 510 for AMD PDUs (or another PDU format for RLC-AM). As a result, if UE 120 does not support RLC-AM for multicast / broadcast messages, UE 120 may not be enabled or may be unable to receive multicast / broadcast messages using formats associated with RLC-AM (such as PDU format 510 for RLC-AM or another PDU format). Therefore, if base station 110 enables or configures RLC-AM for multicast / broadcast messages, base station 110 may need to transmit a first multicast / broadcast message using a format associated with RLC-AM (so that UE 120 supporting RLC-AM for multicast / broadcast messages can operate according to RLC-AM for multicast / broadcast messages). Additionally, base station 110 may need to transmit a second multicast / broadcast message using a format associated with RLC-UM (e.g., indicating the same information as the first multicast / broadcast message) (so that UE 120 not supporting RLC-AM for multicast / broadcast messages can receive the second multicast / broadcast message and operate according to RLC-UM). This introduces additional complexity and signaling overhead associated with transmitting the same information in separate multicast or broadcast messages.

[0083] As another example, in some scenarios, base station 110 may use network decoding for multicast / broadcast messages. For instance, in a network decoding procedure, an encoder (or transmitter) may use network decoding to encode data (such as a set of source packets or original packets) into a set of encoded packets. The encoded packets may be the same as the source packets, may be redundant versions of the source packets, may include combinations of multiple source packets (e.g., subsets of source packets), or may include redundant versions of combinations, etc. The encoder transmits the encoded packets to a decoder (or receiver). The decoder uses network decoding to decode the encoded packets and recover the source packets. As used herein, network decoding may be performed using any type of network decoding scheme, such as fountain decoding, linear network decoding, random linear network decoding, Rupee transform (LT) network decoding, or Raptor network decoding, etc. For example, base station 110 using network decoding for multicast / broadcast messages may transmit one or more redundant packets (or parity packets) for multicast / broadcast messages as part of the network decoding procedure. However, UE 120, which does not support network decoding for multicast / broadcast messages, may be unable to decode or recognize redundant packets (or parity packets) used for multicast / broadcast messages. Therefore, base station 110 may need to transmit multiple data streams for multicast / broadcast messages (e.g., one data stream uses network decoding while another does not). This introduces additional complexity and signaling overhead associated with transmitting the same information in separate multicast or broadcast messages.

[0084] The aspects generally relate to RLC forward compatibility for multicast or broadcast messages. Some aspects more specifically relate to enabling base station 110 to transmit a single multicast or broadcast data stream that enables a first UE 120 to operate according to RLC-UM for the single multicast / broadcast data stream and enables a second UE to operate according to RLC-AM for the single multicast / broadcast data stream. In some aspects, a first UE 120 that does not support RLC-AM for multicast / broadcast messages may be able to decode multicast / broadcast messages using a format associated with RLC-AM. For example, when a multicast / broadcast message uses a format associated with RLC-AM, the first UE 120 may identify and extract information associated with RLC-UM from the multicast / broadcast message. The first UE 120 may use the information extracted from the multicast / broadcast message to operate according to RLC-UM. For example, the first UE can extract information associated with RLC-UM (such as segmentation information or sequence number) and can receive RLC packets from the base station according to RLC-UM (such as without providing feedback information that would otherwise be associated with RLC-AM).

[0085] In some respects, the first UE 120 may identify, at least in part, that the format associated with RLC-AM is used for multicast / broadcast messages based on receiving an RRC configuration indicating that the UE 120 will use RLC-AM for multicast / broadcast. The first UE 120 may decode the multicast / broadcast messages using the format associated with RLC-AM, ignore the RRC configuration, and operate according to the RLC-UM used for multicast / broadcast messages using the format associated with RLC-AM.

[0086] In some other aspects, base station 110 may use a PDU format (e.g., MBS PDU format) associated with multicast or broadcast services (MBS) or point-to-multipoint services. The MBS PDU format may include one or more reserved bits or one or more other bits associated with RLC-AM. A first UE 120 that does not support RLC-AM for multicast / broadcast messages may ignore one or more reserved bits or one or more other bits associated with RLC-AM and may be able to receive and decode multicast / broadcast messages using the MBS PDU format, enabling the first UE 120 to operate according to RLC-AM for multicast / broadcast messages. Similarly, a second UE 120 that supports RLC-AM for multicast / broadcast messages may identify and decode bits associated with RLC-AM, enabling the second UE 120 to operate according to RLC-AM for the same multicast / broadcast messages using the MBS PDU format.

[0087] In some other aspects, base station 110 may be able to indicate whether a packet is associated with a network decoding feature or a forward error correction feature using reserved bits or PDCP PDU format in the RLC header that indicates whether the packet is a parity packet or a redundant packet for network decoding features or forward error correction features. In some other aspects, base station 110 may be able to indicate whether a packet is associated with a network decoding feature or a forward error correction feature using an RLC control PDU header that includes a D / C field and a CPT field (where the CPT field indicates whether the packet is a parity packet or a redundant packet for network decoding features or forward error correction features). Therefore, UE 120, which does not support network decoding features or forward error correction features for multicast / broadcast messages, may ignore or discard packets associated with network decoding features or forward error correction features (because reserved bits or unrecognized PDCP PDU format are used for the packet). Additionally, UE 120, which supports network decoding features or forward error correction features for multicast / broadcast messages, can identify packets associated with these features (e.g., based at least in part on information conveyed via reserved bits or PDCP PDU format). Therefore, UE 120 can receive or decode packets to enable it to operate according to the network decoding features or forward error correction features for multicast / broadcast messages.

[0088] Specific aspects of the subject matter described in this disclosure can be implemented to achieve one or more of the following potential advantages. In some examples, the described techniques can be used to enable a single multicast / broadcast message to support a first UE 120 that does not support features or enhancements and a second UE 120 that does support features or enhancements. For example, a single multicast / broadcast data stream can enable the first UE 120 to operate according to RLC-UM for the single multicast / broadcast data stream, and can enable the second UE to operate according to RLC-AM for the single multicast / broadcast data stream. Additionally or alternatively, a single multicast / broadcast data stream can enable the first UE 120 to discard parity packets or redundant packets while still receiving information included in the single multicast / broadcast data stream, and can enable the second UE 120 to operate according to network decoding features or forward error correction features for the multicast / broadcast data stream. This saves the signaling overhead that would otherwise be used to transmit multiple multicast / broadcast messages to support a first UE that does not support features or enhancements and a second UE that does support features or enhancements within a cellular or wireless network. Furthermore, this reduces the complexity associated with ensuring forward compatibility of RLC features related to multicast / broadcast messages.

[0089] Figures 6A-6E This is a diagram illustrating an example of RLC forward compatibility 600 for multicast or broadcast messages according to this disclosure. (See diagram for example.) Figure 6A As shown, base station 110 and one or more UEs 120 can communicate with each other. For example, base station 110 can communicate with a first UE 120 and a second UE 120. In some aspects, base station 110, the first UE 120, and the second UE 120 may be included in a wireless network (such as wireless network 100). In some aspects, the first UE 120 may be associated with a first capability for multicast / broadcast messages, and the second UE 120 may be associated with a second capability for multicast / broadcast messages. For example, the first UE 120 may operate according to a first version of a wireless communication standard, and the second UE 120 may operate according to a second version of the wireless communication standard (wherein the second version enables the second UE 120 to operate according to different capabilities of the first UE 120).

[0090] For example, in some aspects, the first UE 120 may only support (or may only be able to operate according to) RLC-UM for multicast / broadcast messages. The second UE 120 may support both RLC-UM and RLC-AM for multicast / broadcast messages (or may be able to operate according to both). As another example, the first UE 120 may not support (or may not be able to operate according to) network decoding features or forward error correction features for multicast / broadcast messages. Conversely, the second UE 120 may support (or may be able to operate according to) network decoding features or forward error correction features for multicast / broadcast messages. Although the examples described herein are described in combination to enable the second UE 120 to operate according to RLC-AM and the first UE 120 to operate according to RLC-UM for the same multicast / broadcast messages, the operations and techniques described herein can be used to enable the second UE 120 to operate with the same multicast / broadcast messages according to any features or capabilities that the first UE 120 does not support (while still enabling the first UE 120 to receive and decode multicast / broadcast messages). Additionally, as used herein, "indicating" a feature or enhanced capability supported by UE 120 does not necessarily mean that UE 120 reports or transmits that capability to base station 110. For example, in some aspects, the first UE 120 and the second UE 120 may not transmit or report any of the aforementioned capabilities to base station 110. For example, in some aspects, UE 120 (either the first UE 120 or the second UE 120) may not transmit an indication of its capabilities to base station 110. In other aspects, UE 120 (either the first UE 120 or the second UE 120) may transmit an indication of its capabilities to base station 110.

[0091] In the first operation 605, in some aspects, base station 110 may transmit (e.g., broadcast) an RRC configuration indicating the RLC mode (e.g., RLC-UM or RLC-AM) that UE 120 will use for multicast / broadcast messages transmitted by base station 110. For example, the RRC configuration may indicate that UE 120 located in a cell associated with base station 110 will use RLC-AM for multicast / broadcast messages transmitted by base station 110. In some aspects, the second UE 120 (which is capable of operating according to RLC-AM or RLC-UM for multicast / broadcast messages) can receive the RRC configuration and operate according to the RLC mode indicated by the RRC configuration. In some other aspects, such as when base station 110 uses only the RLC-AM format for multicast / broadcast messages, if the RRC configuration indicates that RLC-UM is to be used for multicast / broadcast messages, the second UE 120 may identify that the fields associated with RLC-AM will be ignored by UE 120 for multicast / broadcast messages transmitted by base station 110.

[0092] In some respects, the first UE 120 (which can only operate according to RLC-UM for multicast / broadcast messages) can receive RRC configuration. If the RRC configuration indicates that the first UE 120 should operate according to RLC-AM, then UE 120 can identify or determine the format associated with RLC-AM to be used by base station 110 for multicast / broadcast messages. As described in more detail herein, the first UE 120 can ignore or disregard the RRC configuration indicating that the first UE 120 should operate according to RLC-AM, and can operate according to RLC-UM for multicast / broadcast messages transmitted by the first UE 120. In other words, the first UE 120 can use the RRC configuration as an indication of the format associated with RLC-AM to be used for multicast / broadcast messages, so that UE 120 can correctly receive and decode the multicast / broadcast messages (and operate according to RLC-UM), as described in more detail herein.

[0093] In the second operation 610, base station 110 may generate multicast / broadcast messages using a format associated with RLC-AM. For example, base station 110 may use a format associated with RLC-AM to generate multicast / broadcast messages so that the second UE 120 (or another UE 120 capable of supporting RLC-AM for multicast / broadcast messages) can operate according to RLC-AM for multicast / broadcast messages. In some aspects, this format may be a format associated with an AMD PDU for multicast / broadcast messages. For example, the multicast / broadcast message generated by base station 110 (in the second operation 610) may include an RLC header indicating information associated with RLC-UM (e.g., SI or sequence number) and RLC-AM (e.g., D / C bits and polling bits).

[0094] In some other respects, the format may be a format associated with MBS or point-to-multipoint services. For example, the format may be an RLC PDU format associated with MRB, MBS, or point-to-multipoint services (referred to herein as the "MBS format"). The MBS format may include one or more reserved bits or one or more other bits associated with RLC-AM (e.g., for indicating D / C information or polling indication). The first UE 120 and the second UE 120 may be configured to support the MBS format. As described in more detail herein, the first UE 120 may be configured to ignore or disregard one or more reserved bits or one or more other bits associated with RLC-AM. Thus, the first UE 120 may be able to receive information from the RLC PDU using the MBS format and may operate according to the RLC-UM used for multicast / broadcast messages using the MBS format. Additionally, the second UE 120 may be configured to identify and extract information from one or more reserved bits or one or more other bits associated with RLC-AM. As a result, the second UE 120 can receive information associated with RLC-AM from the MBS format and can operate according to RLC-AM used for multicast / broadcast messages in the MBS format. In some aspects, the MBS format may include an indication of whether RLC-AM or RLC-UM should be used for the PDU. Therefore, the first UE 120 and the second UE 120 can identify the RLC mode associated with the PDU (e.g., in the absence of RRC configuration).

[0095] In the third operation 615, base station 110 may transmit multicast / broadcast messages using a format such as that associated with RLC-AM. For example, the multicast / broadcast messages may be destined for both first UE 120 and second UE 120 (or... Figure 6AThe multicast message is a group of UE 120s (one or more other UEs 120 not depicted in the text). In some other aspects, the multicast / broadcast message may be a broadcast message, and the first UE 120 and the second UE 120 may be located in an area associated with the cell of base station 110, such that the first UE 120 and the second UE 120 are able to receive the broadcast message. For example, the first UE 120 and the second UE 120 may receive the multicast / broadcast message using a format associated with RLC-AM. As described above, base station 110 may use a format associated with RLC-AM to transmit the multicast / broadcast message. For example, the multicast / broadcast message may use an RLC format associated with an AMD PDU used for the multicast / broadcast message. In some other aspects, the multicast / broadcast message may use an MBS format (e.g., an RLC PDU format for MBS).

[0096] In the fourth operation 620, the first UE 120 may decode multicast / broadcast messages to identify information associated with RLC-UM. For example, based at least in part on the capabilities of the first UE 120 (such as the first UE 120 not supporting RLC-AM for multicast / broadcast messages), the first UE 120 may decode multicast / broadcast messages (which use a format associated with RLC-AM) to identify information associated with RLC-UM. For example, in some aspects, the first UE 120 may be able to support formats associated with both RLC-UM and RLC-AM (while simultaneously supporting only the RLC-UM protocol for multicast / broadcast messages). In some other aspects, the first UE 120 may be able to support only the formats associated with RLC-AM (while simultaneously supporting only the RLC-UM protocol for multicast / broadcast messages). In some other aspects, the first UE 120 may support MBS formats (e.g., RLC PDU format for MBS).

[0097] For example, if the multicast / broadcast message uses a format associated with RLC-AM, the first UE 120 may be able to identify or understand that format, enabling the UE 120 to identify the location of information within the multicast / broadcast message (such as in the RLC header of the multicast / broadcast message). For example, the first UE 120 may be able to identify information associated with or applicable to RLC-UM in a multicast / broadcast message using a format associated with RLC-AM. The first UE 120 may extract information associated with or applicable to RLC-UM from the multicast / broadcast message. For example, in the fourth operation 620, the first UE 120 may extract the SI or SN from the multicast / broadcast message at least in part based on identifying the SI and SN in the multicast / broadcast message. In some aspects, in the fourth operation 620, the first UE 120 may ignore or disregard fields or information associated with RLC-AM in the multicast / broadcast message. For example, the first UE 120 may ignore or disregard fields or information associated with polling information or segment offset information, etc. In another example, UE 120 may use D / C indication to determine whether a packet is a data or control packet, but may ignore or disregard one or more fields or information associated with RLC-AM in the multicast / broadcast message. As a result, in the fourth operation 620, the first UE 120 may be able to decode and extract information from the multicast / broadcast message (which uses a format associated with RLC-AM) so that the first UE 120 can operate according to the RLC-UM used for multicast / broadcast. Furthermore, since the first UE 120 can be configured to recognize or understand the format associated with RLC-AM, the first UE 120 may not automatically discard or ignore the multicast / broadcast message.

[0098] In some other respects, if the multicast / broadcast message uses the RLC PDU format associated with the MBS, the first UE 120 may ignore or disregard fields in the RLC PDU format associated with the MBS that are not applicable to RLC-UM. For example, in the fourth operation 620, the first UE 120 may ignore or disregard one or more reserved fields in the header of the multicast / broadcast message using the RLC PDU format associated with the MBS, or one or more fields associated with RLC-AM. For example, one or more reserved fields or one or more fields associated with RLC-AM may be used to indicate information associated with RLC-AM, such as polling information, D / C indication, or segment offset information. Therefore, the first UE 120 can decode the multicast / broadcast by identifying and extracting information associated with RLC-UM (such as SI or SN) from the RLCPDU format associated with the MBS, while ignoring or disregarding information associated with RLC-AM (such as polling indication or segment offset information).

[0099] In the fifth operation 625, the second UE 120 can decode the multicast / broadcast message to identify information associated with RLC-AM. For example, because the second UE 120 may be able to support RLC-AM for multicast / broadcast messages, the second UE 120 can decode the multicast / broadcast message to identify information associated with RLC-AM. For example, the second UE 120 may support the RLC-AM format because the second UE 120 is able to operate according to RLC-AM for multicast / broadcast messages. Therefore, if the multicast / broadcast message (e.g., using the bit fields of the multicast / broadcast message) or the RRC configuration instructs the second UE 120 to operate according to RLC-AM, the second UE 120 can decode the multicast / broadcast message to identify information associated with RLC-AM.

[0100] In some aspects, where base station 110 uses only the format associated with RLC-AM and the RRC configuration instructs second UE 120 to operate in RLC-UM, second UE 120 can decode multicast / broadcast messages to identify information associated with RLC-UM in a manner similar to that described above in conjunction with fourth operation 620 and first UE 120. For example, second UE 120 can ignore one or more fields associated with RLC-AM in the multicast / broadcast message and can extract information associated with RLC-UM to enable second UE 120 to operate in RLC-UM. In some other aspects, if the multicast / broadcast message uses the RLC PDU format associated with MBS and the RRC configuration instructs second UE 120 to operate in RLC-UM, second UE 120 can decode the multicast / broadcast by identifying and extracting information associated with RLC-UM (such as SI or SN) from the RLC PDU format associated with MBS, while ignoring or disregarding information associated with RLC-AM (such as polling indicators or segment offset information). This allows the second UE 120 to operate in RLC-AM or RLC-UM (e.g., depending on the RRC configuration or indication in the multicast / broadcast message), while also allowing the first UE 120 to operate in RLC-AM for the same multicast / broadcast data stream.

[0101] In the sixth operation 630, the first UE 120 may operate according to RLC-UM for multicast / broadcast messages. For example, the first UE 120 may be able to operate according to RLC-UM for multicast / broadcast messages, at least in part based on decoding the multicast / broadcast messages to identify information associated with RLC-UM (in the fourth operation 620). For example, if the RRC configuration indicates that the UE 120 associated with base station 110 is to operate according to RLC-AM for multicast / broadcast messages, the first UE 120 may use the RRC configuration as an indication of the format associated with RLC-AM to be used by base station 110. The first UE 120 may decode the multicast / broadcast messages to identify information associated with RLC-UM, at least in part based on identifying the format associated with RLC-AM to be used by base station 110. The first UE 120 may operate according to RLC-UM regardless of the RRC configuration. In other words, the first UE 120 can ignore or disregard the RRC configuration that instructs the first UE 120 to operate according to RLC-AM, and can operate according to RLC-UM for multicast / broadcast messages.

[0102] In the seventh operation 635, the second UE 120 may operate according to the RLC-AM for multicast / broadcast messages. For example, the second UE 120 may be able to operate according to the RLC-AM for multicast / broadcast messages, at least in part based on decoding the multicast / broadcast messages to identify information associated with the RLC-AM (in the fifth operation 625). For example, if the RRC configuration indicates that the UE 120 associated with base station 110 is to operate according to the RLC-AM for multicast / broadcast messages, then the second UE 120 may receive, decode, and operate according to the RLC-AM for multicast / broadcast messages.

[0103] As a result, for the same multicast / broadcast message, the first UE 120 can operate according to RLC-UM, and the second UE 120 can operate according to RLC-AM.

[0104] For example, in the eighth operation 640, the second UE 120 may transmit feedback information (ACK or NACK feedback) regarding the multicast / broadcast message to the base station 110. For example, if the multicast / broadcast message includes an indication to request polling (such as using the polling indicator field in the RLC header of the multicast / broadcast message), the second UE 120 may transmit feedback information (ACK or NACK feedback) regarding the multicast / broadcast message to the base station 110 according to RLC-AM.

[0105] In operation 645, base station 110 may transmit one or more retransmissions of previously transmitted RLC PDUs or redundant packets associated with multicast / broadcast messages, based on network decoding features or forward error correction features, or a combination thereof. In some aspects, the first UE 120 or the second UE 120 may determine that a packet is associated with a retransmission based at least in part on the SN associated with a previously transmitted packet (e.g., an indication that a packet is a retransmission may be that the same SN as the previous packet is included in the packet header). In some aspects, base station 110 may use reserved fields in the RLC header to indicate that the packet is a redundant packet for network decoding features or forward error correction features. For example, base station 110 may use reserved fields in existing PDU formats to indicate that the packet is a redundant packet for network decoding features or forward error correction features (e.g., parity packets). For example, base station 110 (or the wireless communication standard) may define or indicate that reserved fields in existing PDU formats are to be used to indicate that a packet is a redundant packet for a multicast / broadcast data stream. In some other aspects, base station 110 may be able to use an RLC control PDU header that may include a D / C field and a control PDU type (CPT) field (where the CPT field indicates whether the packet is a parity packet or a redundant packet for network decoding features or forward error correction features) to indicate whether the packet is associated with network decoding features or forward error correction features.

[0106] As described above, the first UE 120 can operate in RLC-UM. Additionally, in the tenth operation 650, since the reserved field is used to indicate that a packet is a parity packet, the first UE 120 can discard or abandon the packet. The first UE 120 can continue to receive other packets and operate according to RLC-UM, as described above. However, in the eleventh operation 655, the second UE 120 is able to identify whether a packet is a retransmission, or to identify an indication of a redundant or parity packet in the reserved field (e.g., at least in part based on the capabilities of the second UE 120). Therefore, the second UE 120 can receive and decode retransmitted packets, or receive redundant or parity packets and can perform network decoding to enable the second UE 120 to operate according to network decoding features or forward error correction features for multicast / broadcast messages. For example, a procedure can be defined to enable the second UE 120 to operate according to network decoding features or forward error correction features for multicast / broadcast messages. For example, the first M bytes of data in a redundant or parity block can indicate which SNs the parity bits correspond to, as described below.

[0107] In some other aspects, in the ninth operation 645, one or more redundant packets associated with multicast / broadcast messages based on network decoding characteristics or forward error correction characteristics can use the PDCP PDU format to indicate that(s) the packets are redundant or parity packets. In the tenth operation 650, the first UE 120 may discard or abandon(s) the packets because the first UE 120 may not recognize or understand the PDCP PDU format. In the eleventh operation 655, the second UE 120 may be able to recognize or understand the PDCP PDU format. Therefore, the second UE 120 can use(s) the PDCP PDU format associated with redundant or parity packets for multicast / broadcast messages to receive and perform network decoding.

[0108] In some respects, the use of redundant or parity packets may cause gaps or holes in the SN (Signal Node) used by base station 110 for multicast / broadcast messages. For example, if a multicast / broadcast message is associated with 10 original packets and 2 parity (redundant) packets, the first UE 120 may receive the first 10 original packets, but there may be an SN gap caused by the 2 parity packets (because the first UE 120 may not receive or may discard the 2 parity packets, as described above). Therefore, if network decoding features or forward error correction features are used for multicast / broadcast messages, the first UE 120 may be configured to operate according to RLC-UM for multicast / broadcast messages (even if the first UE 120 is capable of supporting RLC-AM). For example, since the first UE 120 may not be able to receive or receive parity packets, the first UE 120 should be configured to operate according to RLC-UM to mitigate SN gaps or holes caused by parity packets.

[0109] Furthermore, the use of redundant or parity packets may result in gaps or holes in the SNs of UE 120 that does not support network decoding or forward error correction features. For example, if UE 120 successfully receives all the original packets after receiving the first parity packet, UE 120 may not receive or decode the second parity packet transmitted by base station 110. Therefore, gaps in the SNs of UE 120 may occur by not receiving or decoding the second parity packet. Therefore, in some aspects, the PDCP PDU format associated with redundant or parity packets for multicast / broadcast messages may include a field indicating the range of PDCP SNs associated with the packet. For example, instead of including the SN for the PDCP PDU, base station 110 may generate parity packets and include an indication of the PDCP SN associated with the parity packet. For example, if the parity packet is associated with PDCP SNs 1 to 10, a field in the PDCP PDU may indicate that the packet is associated with PDCP SNs 1 to 10 (instead of indicating the PDCP SN for the parity packet). Therefore, the second UE 120 can identify that a packet is a parity packet for multicast / broadcast messages, and can also mitigate problems caused by SN gaps or holes. For example, the second UE 120 can avoid determining that a packet was not successfully received (and thus transmitting a NACK feedback or requesting a retransmission of the packet), as might happen if the second UE 120 identifies a gap or hole in the PDCP SN received by the second UE 120.

[0110] Figure 6B-6E This indicates the configuration or operation performed by the first UE 120 and the second UE 120 for the same multicast / broadcast message. (As in...) Figure 6BAs shown, the first UE 120 can operate according to configuration 660 for multicast / broadcast messages. For example, the first UE 120 may only support the RLC-UM protocol for multicast / broadcast messages. The first UE 120 can be configured to support both the RLC-UM and RLC-AM formats for multicast / broadcast messages. As described in more detail elsewhere herein, if the RLC-AM format is used for multicast / broadcast messages, the first UE 120 can decode the multicast / broadcast messages by identifying and extracting information associated with RLC-UM, and can ignore or disregard fields associated with RLC-AM. Therefore, the first UE 120 can always operate in RLC-UM, regardless of whether the RLC-UM or RLC-AM format is used for multicast / broadcast messages. The second UE 120 can operate according to configuration 665 for multicast / broadcast messages. For example, the second UE 120 may support both the RLC-UM format and protocol for multicast / broadcast messages. Additionally, the second UE 120 can support the RLC-AM format and procedures for multicast / broadcast messages. Therefore, the second UE 120 can operate in the RLC mode indicated by the RRC configuration.

[0111] In some other aspects, such as Figure 6CAs shown, the first UE 120 can operate according to configuration 670 for multicast / broadcast messages. In configuration 670, the first UE 120 may only support the RLC-UM protocol for multicast / broadcast messages (and not the RLC-AM protocol), but may only support the RLC-AM format for multicast / broadcast messages (and not the RLC-UM format). This reduces the complexity associated with configuring the first UE 120, as the first UE 120 (and the second UE 120) may not need to recognize or understand multiple RLC formats for multicast / broadcast messages. As described in more detail elsewhere herein, the first UE 120 can decode multicast / broadcast messages by identifying and extracting information associated with RLC-UM from the multicast / broadcast messages, and can ignore or disregard fields associated with RLC-AM in the multicast / broadcast messages. Therefore, even when using the RLC-AM format, the first UE 120 can always operate in RLC-UM for multicast / broadcast messages. The second UE 120 can operate according to the configuration 675 for multicast / broadcast messages. For example, the second UE 120 may support both RLC-AM and RLC-UM protocols for multicast / broadcast messages, but may only support the RLC-AM format (instead of the RLC-UM format). If the RRC configuration indicates that RLC-AM should be used, the second UE 120 may be able to operate according to the RLC-AM format for multicast / broadcast messages (while the first UE 120 operates according to the RLC-UM format for the same multicast / broadcast messages). However, since the base station 110 can only use the RLC-AM format, if the RRC configuration indicates that RLC-UM should be used, the second base station 110 can decode the multicast / broadcast messages by identifying and extracting the information associated with RLC-UM from the multicast / broadcast messages, and may ignore or disregard the fields associated with RLC-AM in the multicast / broadcast messages to enable the second UE 120 to operate in RLC-UM.

[0112] In some other aspects, such as Figure 6DAs shown, the first UE 120 can operate according to configuration 680 for multicast / broadcast messages. For example, the first UE 120 may only support the RLC-UM protocol for multicast / broadcast messages. The first UE 120 may be configured to support both the RLC-UM format and the RLC-AM format for multicast / broadcast messages. As described in more detail elsewhere herein, the first UE 120 may identify the RLC-AM format to be used for multicast / broadcast messages based at least in part on receiving an RRC configuration that configures the UE 120 to use RLC-AM for multicast / broadcast messages. Therefore, the first UE 120 may be able to decode multicast / broadcast messages by identifying and extracting information associated with RLC-UM from the multicast / broadcast messages, and may ignore or disregard fields associated with RLC-AM in the multicast / broadcast messages. Thus, even if the RRC configuration instructs the UE 120 to use RLC-AM for multicast / broadcast messages, the first UE 120 may always operate in RLC-UM for multicast / broadcast messages. The second UE 120 can operate according to the configuration 685 for multicast / broadcast messages. For example, the second UE 120 can support the RLC-UM format and procedures for multicast / broadcast messages. Additionally, the second UE 120 can support the RLC-AM format and procedures for multicast / broadcast messages. Therefore, the second UE 120 can operate in the RLC mode indicated by the RRC configuration.

[0113] In some other aspects, such as Figure 6EAs shown, the RLC PDU format used for MBS or point-to-multipoint services can be used for multicast / broadcast messages. The first UE 120 can operate according to configuration 690 for multicast / broadcast messages. For example, the first UE 120 can support the RLC PDU format used for MBS or point-to-multipoint services. The first UE can only support the RLC-UM protocol (instead of the RLC-AM protocol) for multicast / broadcast messages. For example, the first UE 120 can recognize or understand the RLC PDU format used for MBS or point-to-multipoint services. The first UE 120 can decode multicast / broadcast messages by ignoring or disregarding reserved or RLC-AM-associated fields in the RLC PDU format used for MBS or point-to-multipoint services. Therefore, the first UE 120 can always operate in RLC-UM for multicast / broadcast messages. The second UE 120 can operate according to configuration 695 for multicast / broadcast messages. For example, the second UE 120 can support the RLCPDU format used for MBS or point-to-multipoint services. Additionally, the second UE 120 may support RLC-AM and RLC-UM for multicast / broadcast messages. Therefore, the second UE 120 may operate in an RLC mode indicated by the multicast / broadcast message (e.g., in fields of the RLC PDU format for MBS or point-to-multipoint services) or in an RLC mode indicated by the RRC configuration. For example, if the second UE 120 is to operate in RLC-UM, it can decode the multicast / broadcast message by ignoring or disregarding the reserved or RLC-AM-associated fields in the RLC PDU format for MBS or point-to-multipoint services.

[0114] As a result, by using one or more of the operations or configurations described herein, UE 120s with different capabilities can operate according to different capabilities for the same multicast / broadcast data stream. For example, for the same multicast / broadcast data stream, a first UE 120 may be able to operate according to RLC-UM, and a second UE 120 may be able to operate according to RLC-AM. This reduces complexity and minimizes the signaling overhead associated with ensuring forward compatibility of RLCs used in multicast / broadcast messages.

[0115] Figure 7 This is a flowchart illustrating an example process 700 performed by a UE according to this disclosure. Example process 700 is where a UE (e.g., UE 120, such as...) Figures 6A-6E Examples of operations performed by the first UE 120 or the second UE 120 in relation to RLC forward compatibility for multicast or broadcast messages.

[0116] like Figure 7As shown, in some aspects, process 700 may include receiving from a base station a multicast message or broadcast message using an RLC format associated with RLC-AM (box 710). For example, a UE (such as by using...) Figure 9 The receiving component 902 described herein can receive multicast or broadcast messages using the RLC format associated with RLC-AM from the base station, as described above.

[0117] As in Figure 7 As further illustrated herein, in some aspects, process 700 may include, at least in part, decoding multicast or broadcast messages to identify information associated with RLC-UM based on the UE's capabilities (box 720). For example, the UE (such as by using...) Figure 9 The decoding component 910 described herein can at least partially rely on the UE's capabilities to decode multicast or broadcast messages to identify information associated with the RLC Unacknowledged Mode (RLC-UM), as described above.

[0118] As in Figure 7 As further illustrated, in some aspects, process 700 may include operating according to RLC-UM based at least in part on decoding multicast or broadcast messages (box 730). For example, a UE (such as by using...) Figure 9 The receiving component 902 or transmitting component 906 described herein may operate according to RLC-UM, at least in part, based on decoding multicast or broadcast messages, as described above.

[0119] Process 700 may include additional aspects, such as any single aspect or any combination of aspects described below or in conjunction with one or more other processes described elsewhere herein.

[0120] In the first additional aspect, the UE supports the RLC format associated with RLC-AM and different RLC formats associated with RLC-UM, and the UE is able to operate only according to RLC-UM used for multicast messages or broadcast messages.

[0121] In a second additional aspect, either alone or in combination with the first aspect, the UE supports only the RLC format associated with the RLC-AM, and the UE is able to operate only according to the RLC-UM used for multicast messages or broadcast messages.

[0122] In a third additional aspect, either alone or in combination with one or more of the first and second aspects, decoding the multicast message or the broadcast message includes identifying one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM, and decoding the multicast message or the broadcast message is based at least in part on extracting information associated with the RLC-AM from one or more other fields of the multicast message or the broadcast message and ignoring the one or more fields associated with the RLC-AM.

[0123] In a fourth additional aspect, operating according to the RLC-UM, either alone or in combination with one or more of the first to third aspects, includes operating according to the RLC-UM based at least in part on extracting information associated with the RLC-UM from one or more fields of the multicast message or broadcast message.

[0124] In a fifth additional aspect, either alone or in combination with one or more of the first to fourth aspects, the UE is capable of operating according to the RLC-AM or the RLC-UM for multicast messages or broadcast messages, and process 700 includes receiving an RRC configuration instructing the UE to operate according to the RLC-UM for multicast messages or broadcast messages, and decoding the multicast message or broadcast message includes decoding the multicast message or broadcast message at least in part based on extracting information associated with the RLC-UM from one or more other fields of the multicast message or broadcast message and ignoring the one or more fields associated with the RLC-AM.

[0125] In a sixth additional aspect, either alone or in combination with one or more of the first to fifth aspects, process 700 includes receiving from the base station an RRC configuration indicating that the RLC-AM is to be used for a multicast message or a broadcast message, and decoding the multicast message or the broadcast message includes decoding the multicast message or the broadcast message at least in part based on receiving the RRC configuration indicating that the base station is to use the RLC format associated with the RLC-AM, and operating according to the RLC-UM includes operating according to the RLC-UM at least in part based on decoding the multicast message or the broadcast message.

[0126] In a seventh additional aspect, either alone or in combination with one or more of the first to sixth aspects, process 700 includes receiving from the base station an RRC configuration indicating that the RLC-AM is to be used for a multicast message or a broadcast message, and decoding the multicast message or the broadcast message includes decoding the multicast message or the broadcast message based at least in part on ignoring one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM.

[0127] In the eighth additional aspect, either alone or in combination with one or more of the first to seventh aspects, the RLC format associated with the RLC-AM is an RLC PDU format for MRB, and receiving the multicast message or the broadcast message includes receiving the multicast message or the broadcast message using the RLC PDU format for MRB, and including one or more reserved fields in the header of the multicast message or the broadcast message, or one or more fields associated with the RLC-AM.

[0128] In the ninth additional aspect, decoding the multicast message or the broadcast message, either alone or in combination with one or more of the first to eighth aspects, includes decoding the multicast message or the broadcast message based at least in part on ignoring the one or more reserved fields or the one or more fields associated with the RLC-AM.

[0129] In the tenth additional aspect, either alone or in combination with one or more of the first to ninth aspects, process 700 includes receiving a packet associated with the multicast message or the broadcast message, the packet including a field indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features.

[0130] In the eleventh additional aspect, alone or in combination with one or more of the first to tenth aspects, process 700 includes receiving a packet associated with the multicast message or the broadcast message, the packet using a PDCP PDU format associated with redundant packets used for network decoding features or forward error correction features.

[0131] In the twelfth additional aspect, receiving the packet, either alone or in combination with one or more of the first to eleventh aspects, includes receiving the packet including a field indicating a range of PDCP sequence numbers associated with the packet or a control PDU type (CPT) field indicating that the packet is a redundant packet.

[0132] In the thirteenth additional aspect, alone or in combination with one or more of the first to twelfth aspects, the UE is capable of operating solely based on the RLC-UM for multicast or broadcast messages, and process 700 includes receiving a packet associated with the multicast or broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features, and discarding the packet at least in part based on the fact that the packet is a redundant packet for the network decoding features or the forward error correction features.

[0133] In the fourteenth additional aspect, either alone or in combination with one or more of the first to thirteenth aspects, the UE is capable of operating according to the RLC-AM or RLC-UM for multicast or broadcast messages, and process 700 includes receiving a packet associated with the multicast or broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features, and decoding the packet at least in part based on the indication that the packet is a retransmission or redundant packet for the network decoding features or the forward error correction features.

[0134] although Figure 7 An example box of process 700 is shown, but in some respects, process 700 may include... Figure 7 The boxes depicted in the process are compared to additional boxes, fewer boxes, different boxes, or boxes arranged differently. Additionally or alternatively, two or more boxes in process 700 can be executed in parallel.

[0135] Figure 8 This is a flowchart illustrating an example process 800 performed, for example, by a base station according to this disclosure. Example process 800 is an example in which a base station (e.g., base station 110) performs operations associated with RLC forward compatibility for multicast or broadcast messages.

[0136] As in Figure 8 As shown, in some aspects, process 800 may include: generating multicast or broadcast messages using an RLC format associated with RLC-AM (box 810). For example, a base station (such as by using...) Figure 10 The signal generation component 1008 described herein can use the RLC format associated with RLC-AM to generate multicast or broadcast messages, as described above.

[0137] As in Figure 8 As further illustrated, in some aspects, process 800 may include transmitting a multicast message or broadcast message using an RLC format associated with RLC-AM, wherein transmitting the multicast message or broadcast message enables a first UE to operate according to the RLC-AM used for the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM used for the multicast or broadcast message (block 820). For example, a base station (such as by using...) Figure 10 The transmission component 1006 described herein can transmit multicast messages or broadcast messages using an RLC format associated with RLC-AM, wherein transmitting the multicast message or broadcast message enables a first UE to operate according to the RLC-AM used for the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM used for the multicast or broadcast message, as described above.

[0138] Process 800 may include additional aspects, such as any single aspect or any combination of aspects described below or in conjunction with one or more other processes described elsewhere herein.

[0139] In a first additional aspect, the first UE is capable of operating in RLC-AM or RLC-UM for multicast or broadcast messages, and the second UE is capable of operating only in the RLC-UM for multicast or broadcast messages.

[0140] In a second additional aspect, either alone or in combination with the first aspect, transmitting the multicast message or the broadcast message enables the second UE to operate according to the RLC-UM, at least in part, based on ignoring one or more fields associated with the RLC-AM included in the multicast message or the broadcast message.

[0141] In a third additional aspect, either alone or in combination with one or more of the first and second aspects, process 800 includes transmitting an RRC message indicating that the RLC-AM is to be used for multicast or broadcast messages, and transmitting the RRC message to configure the first UE to operate according to the RLC-AM and enable the second UE to identify that the base station wants to use the RLC format associated with the RLC-AM.

[0142] In a fourth additional aspect, either alone or in combination with one or more of the first to third aspects, the RLC format associated with the RLC-AM is an RLC PDU format for MRB, and transmitting the multicast message or the broadcast message includes transmitting the multicast message or the broadcast message using the RLC PDU format for the MRB, and including one or more reserved fields in the header of the multicast message or the broadcast message, or one or more fields associated with the RLC-AM.

[0143] In a fifth additional aspect, the transmission of the multicast message or the broadcast message, alone or in combination with one or more of the first to fourth aspects, includes transmitting the multicast message or the broadcast message in at least one of the one or more reserved fields that includes an indication that the RLC-AM is to be used for the multicast message or the broadcast message, wherein including the indication in at least one of the one or more reserved fields enables the first UE to operate in the RLC-AM for the multicast message or the broadcast message.

[0144] In a sixth additional aspect, either alone or in combination with one or more of the first to fifth aspects, process 800 includes transmitting a packet associated with the multicast message or the broadcast message, the packet including a field indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features.

[0145] In a seventh additional aspect, either alone or in combination with one or more of the first to sixth aspects, process 800 includes transmitting packets associated with the multicast message or the broadcast message, the packets using a PDCP PDU format associated with redundant packets used for network decoding features or forward error correction features.

[0146] In the eighth additional aspect, the transmission of the packet, alone or in combination with one or more of the first to seventh aspects, includes the transmission of the packet including a field indicating a range of PDCP sequence numbers associated with the packet or a control PDU type (CPT) field indicating that the packet is a redundant packet.

[0147] In the ninth additional aspect, alone or in combination with one or more of the first to eighth aspects, process 800 includes transmitting a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features, and indicating that the packet is a retransmission or redundant packet enables the first UE to decode the packet and operate in the RLC-AM, and enables the second UE to discard the packet and operate in the RLC-UM.

[0148] although Figure 8 An example box of process 800 is shown, but in some respects, process 800 may include... Figure 8 The boxes depicted in the diagram may be fewer, different, or arranged differently compared to additional boxes. Alternatively, two or more boxes in process 800 may be executed in parallel.

[0149] Figure 9 This is a block diagram of an example device 900 for wireless communication according to the present disclosure. Device 900 may be a UE, or a UE may include device 900. In some aspects, device 900 includes a receiving component 902, a communication manager 904, and a transmitting component 906, which can communicate with each other (e.g., via one or more buses). As shown, device 900 may use the receiving component 908 and the transmitting component 902 to communicate with another device 906 (such as a UE, a base station, or another wireless communication device).

[0150] In some respects, device 900 can be configured to perform the functions described herein. Figures 6A-6E The described one or more operations. Additionally or alternatively, device 900 may be configured to perform one or more processes described herein (such as...). Figure 7 The process 700) or a combination thereof. In some aspects, the device 900 may include the above combinations. Figure 2 One or more components of the UE as described.

[0151] Receiver 902 may receive communications (such as reference signals, control information, data communications, or combinations thereof) from device 908. Receiver 902 may provide the received communications to one or more other components of device 900 (such as communication manager 904). In some aspects, receiver 902 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, etc.) and may provide the processed signals to one or more other components. In some aspects, receiver 902 may include a combination of the above. Figure 2 The described UE includes one or more antennas, demodulators, MIMO detectors, receiver processors, controllers / processors, memory, or combinations thereof.

[0152] The transmission component 906 can transmit communications (such as reference signals, control information, data communications, or combinations thereof) to the device 908. In some aspects, the communication manager 904 can generate communications and transmit the generated communications to the transmission component 906 for transmission to the device 908. In some aspects, the transmission component 906 can perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, encoding, etc.) on the generated communications and transmit the processed signals to the device 908. In some aspects, the transmission component 906 can include a combination of the above. Figure 2 The described UE includes one or more antennas, modulators, transmit MIMO processors, transmit processors, controllers / processors, memories, or combinations thereof. In some aspects, the transmit component 906 may be co-located with the receive component 902 in a transceiver.

[0153] The communication manager 904 may receive or enable the receiving component 902 to receive from the base station multicast or broadcast messages using the RLC format associated with RLC-AM. The communication manager 904 may decode the multicast or broadcast messages to identify information associated with RLC-UM, at least in part based on the UE's capabilities. The communication manager 904 may operate according to RLC-UM, at least in part based on the decoded multicast or broadcast messages. In some aspects, the communication manager 904 may perform one or more operations performed by one or more components of the communication manager 904 as described elsewhere herein.

[0154] Communication Manager 904 may include the above combination Figure 2 The described UE includes a controller / processor, memory, or a combination thereof. In some aspects, the communication manager 904 includes a set of components, such as a decoding component 910, etc. Alternatively, this set of components may be separate from and distinct from the communication manager 904. In some aspects, one or more components in the set may include the above combinations. Figure 2The described UE may be implemented within its controller / processor, memory, or a combination thereof. Additionally or alternatively, one or more components of this set of components may be implemented, at least partially, as software stored in memory. For example, a component (or a portion thereof) may be implemented as instructions or code stored in a non-transitory computer-readable medium and may be executed by the controller or processor to perform the function or operation of that component.

[0155] The receiving component 902 can receive multicast or broadcast messages from the base station using the RLC format associated with RLC-AM. The decoding component 910 can decode the multicast or broadcast messages, at least in part, based on the UE's capabilities, to identify information associated with the RLC Unacknowledged Mode (RLC-UM). The receiving component 902 or the transmitting component 906 can operate according to RLC-UM, at least in part, based on decoding the multicast or broadcast messages.

[0156] The receiving component 902 can receive from the base station an RRC configuration indicating whether RLC-AM is to be used for multicast or broadcast messages. The decoding component 910 can decode the multicast or broadcast messages at least in part based on the received RRC configuration indicating that the base station is to use the RLC format associated with RLC-AM. The receiving component 902 or the transmitting component 906 can operate according to RLC-UM at least in part based on the decoded multicast or broadcast messages.

[0157] The receiving component 902 can receive from the base station an RRC configuration indicating whether the RLC-AM is to be used for multicast or broadcast messages. The decoding component 910 can decode multicast or broadcast messages at least in part based on ignoring one or more fields in the multicast or broadcast message that are associated with the RLC-AM.

[0158] The receiving component 902 can receive packets associated with multicast or broadcast messages, the packets including a field indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features.

[0159] The receiving component 902 can receive packets associated with the multicast message or the broadcast message, which use the PDCP PDU format associated with redundant packets used for network decoding features or forward error correction features.

[0160] Figure 9 The number and arrangement of components shown are provided as an example. In practice, different arrangements may exist. Figure 9 The components shown are compared to additional components, fewer components, different components, or components arranged differently. Furthermore, Figure 9 The two or more components shown can be implemented within a single component, or Figure 9The single component shown can be implemented as multiple distributed components. Additionally or alternatively, Figure 9 The set of components shown (e.g., one or more components) can perform actions described as being performed by Figure 9 The other set of components shown performs one or more functions.

[0161] Figure 10 This is a block diagram of an example apparatus 1000 for wireless communication according to the present disclosure. Apparatus 1000 may be a base station, or a base station may include apparatus 1000. In some aspects, apparatus 1000 includes a receiving component 1002, a communication manager 1004, and a transmitting component 1006, which can communicate with each other (e.g., via one or more buses). As shown, apparatus 1000 may use the receiving component 1008 and the transmitting component 1002 to communicate with another apparatus 1006 (such as a UE, a base station, or another wireless communication device).

[0162] In some respects, device 1000 can be configured to perform the functions described herein. Figures 6A-6E The described one or more operations. Additionally or alternatively, device 1000 may be configured to perform one or more processes described herein (such as...). Figure 8 The process 800) or a combination thereof. In some aspects, the device 1000 may include the above combinations. Figure 2 One or more components of the base station described.

[0163] Receiver 1002 may receive communications (such as reference signals, control information, data communications, or combinations thereof) from device 1008. Receiver 1002 may provide the received communications to one or more other components of device 1000 (such as communication manager 1004). In some aspects, receiver 1002 may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, etc.) and may provide the processed signals to one or more other components. In some aspects, receiver 1002 may include a combination of the above. Figure 2 The described base station includes one or more antennas, demodulators, MIMO detectors, receiver processors, controllers / processors, memory, or combinations thereof.

[0164] The transmission component 1006 can transmit communications (such as reference signals, control information, data communications, or combinations thereof) to the device 1008. In some aspects, the communication manager 1004 can generate communications and transmit the generated communications to the transmission component 1006 for transmission to the device 1008. In some aspects, the transmission component 1006 can perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, encoding, etc.) on the generated communications and transmit the processed signals to the device 1008. In some aspects, the transmission component 1006 can include combinations of the above. Figure 2 The described base station includes one or more antennas, modulators, transmit MIMO processors, transmit processors, controllers / processors, memory, or combinations thereof. In some aspects, the transmit component 1006 may be co-located with the receive component 1002 in a transceiver.

[0165] The communication manager 1004 may generate multicast or broadcast messages using an RLC format associated with RLC-AM. The communication manager 1004 may transmit, or cause the transmission component 1006 to transmit, a multicast or broadcast message using an RLC format associated with RLC-AM, wherein transmitting the multicast or broadcast message enables a first UE to operate according to the RLC-AM used in the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM used in the multicast or broadcast message. In some aspects, the communication manager 1004 may perform one or more operations performed by one or more components of the communication manager 1004 as described elsewhere herein.

[0166] Communication Manager 1004 may include the above combination Figure 2 The described base station includes a controller / processor, memory, scheduler, communication unit, or a combination thereof. In some aspects, the communication manager 1004 includes a set of components, such as a signal generation component 1010, etc. Alternatively, this set of components may be separate from and distinct from the communication manager 1004. In some aspects, one or more components in the set may include or may combine the above. Figure 2 The described base station is implemented within a controller / processor, memory, scheduler, communication unit, or a combination thereof. Additionally or alternatively, one or more components of this set of components may be implemented, at least partially, as software stored in memory. For example, a component (or a portion thereof) may be implemented as instructions or code stored in a non-transient computer-readable medium and executable by a controller or processor to perform the function or operation of that component.

[0167] The signal generation component 1010 can generate multicast or broadcast messages using an RLC format associated with RLC-AM. The transmission component 1006 can transmit multicast or broadcast messages using an RLC format associated with RLC-AM, wherein transmitting the multicast or broadcast message enables a first UE to operate according to the RLC-AM used for the multicast or broadcast message, and enables a second UE to operate according to the RLC-UM used for the multicast or broadcast message.

[0168] The transmission component 1006 can transmit an RRC message indicating that the RLC-AM is to be used for multicast or broadcast messages, wherein transmitting the RRC message configures the first UE to operate according to the RLC-AM and enables the second UE to identify that the base station wants to use the RLC format associated with the RLC-AM.

[0169] The transmission component 1006 can transmit packets associated with multicast or broadcast messages, the packets including a field indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features.

[0170] The transmission component 1006 can transmit packets associated with multicast or broadcast messages, which use the PDCP PDU format associated with redundant packets used for network decoding features or forward error correction features.

[0171] The transmission component 1006 can transmit packets associated with multicast or broadcast messages, the packets indicating that the packets are retransmission or redundant packets for network decoding features or forward error correction features, wherein indicating that the packets are retransmission or redundant packets enables a first UE to decode the packets and operate in RLC-AM, and enables a second UE to discard the packets and operate in RLC-UM.

[0172] Figure 10 The number and arrangement of components shown are provided as an example. In practice, different arrangements may exist. Figure 10 The components shown are compared to additional components, fewer components, different components, or components arranged differently. Furthermore, Figure 10 The two or more components shown can be implemented within a single component, or Figure 10 The single component shown can be implemented as multiple distributed components. Additionally or alternatively, Figure 10 The set of components shown (e.g., one or more components) can perform actions described as being performed by Figure 10 The other set of components shown performs one or more functions.

[0173] The following provides an overview of some aspects of this disclosure:

[0174] Aspect 1: A wireless communication method performed by a user equipment (UE), comprising: receiving from a base station a multicast message or a broadcast message using a radio link control (RLC) format associated with an RLC acknowledged mode (RLC-AM); decoding the multicast message or the broadcast message at least in part based on the capability of the UE to identify information associated with an RLC unacknowledged mode (RLC-UM); and operating according to the RLC-UM at least in part based on decoding the multicast message or the broadcast message.

[0175] Aspect 2: The method of aspect 1, wherein the UE supports the RLC format associated with the RLC-AM and different RLC formats associated with the RLC-UM, and wherein the UE is able to operate only according to the RLC-UM used for multicast messages or broadcast messages.

[0176] Aspect 3: The method of Aspect 1, wherein the UE only supports the RLC format associated with the RLC-AM, and wherein the UE is able to operate only according to the RLC-UM used for multicast messages or broadcast messages.

[0177] Aspect 4: The method of any of Aspects 1-3, wherein decoding the multicast message or the broadcast message comprises: identifying one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM; and decoding the multicast message or the broadcast message at least in part based on extracting information associated with the RLC-UM from one or more other fields of the multicast message or the broadcast message and ignoring the one or more fields associated with the RLC-AM.

[0178] Aspect 5: The method of aspects 1-4, wherein operating according to the RLC-UM includes operating according to the RLC-UM based at least in part on extracting the information associated with the RLC-UM from one or more fields of the multicast message or the broadcast message.

[0179] Aspect 6: A method of any of Aspects 1-5, wherein the UE is capable of operating according to the RLC-AM or the RLC-UM for a multicast message or a broadcast message, the method further comprising: receiving a Radio Resource Control (RRC) configuration instructing the UE to operate according to the RLC-UM for a multicast message or a broadcast message, and wherein decoding the multicast message or the broadcast message comprises at least in part based on extracting information associated with the RLC-UM from one or more other fields of the multicast message or the broadcast message and ignoring the one or more fields associated with the RLC-AM.

[0180] Aspect 7: The method of any of Aspects 1-6 further includes: receiving from the base station a Radio Resource Control (RRC) configuration indicating that the RLC-AM is to be used for a multicast message or a broadcast message, wherein decoding the multicast message or the broadcast message includes decoding the multicast message or the broadcast message at least in part based on receiving the RRC configuration indicating that the base station is to use the RLC format associated with the RLC-AM, and wherein operating according to the RLC-UM includes operating according to the RLC-UM at least in part based on decoding the multicast message or the broadcast message.

[0181] Aspect 8: The method of any of Aspects 1-7 further includes receiving from the base station a radio resource control (RRC) configuration indicating that the RLC-AM is to be used for a multicast message or a broadcast message, and wherein decoding the multicast message or the broadcast message includes decoding the multicast message or the broadcast message based at least in part on ignoring one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM.

[0182] Aspect 9: A method of any of Aspects 1-8, wherein the RLC format associated with the RLC-AM is an RLC Packet Data Unit (PDU) format for multicast or broadcast radio bearers (MRB), and wherein receiving the multicast message or the broadcast message includes receiving the multicast message or the broadcast message using the RLC PDU format for the MRB, and including one or more reserved fields in the header of the multicast message or the broadcast message or one or more fields associated with the RLC-AM.

[0183] Aspect 10: The method of aspect 9, wherein decoding the multicast message or the broadcast message includes decoding the multicast message or the broadcast message at least in part based on ignoring the one or more reserved fields or the one or more fields associated with the RLC-AM.

[0184] Aspect 11: The method of any of Aspects 1-10 further includes receiving a packet associated with the multicast message or the broadcast message, the packet including a field indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features.

[0185] Aspect 12: The method of any of Aspects 1-11 further includes receiving a packet associated with the multicast message or the broadcast message, the packet using a Packet Data Convergence Protocol (PDCP) Packet Data Unit (PDU) format associated with redundant packets used for network decoding features or forward error correction features.

[0186] Aspect 13: The method of aspect 12, wherein receiving the packet includes receiving the packet including a field indicating a range of PDCP sequence numbers associated with the packet or a control PDU type (CPT) field indicating that the packet is a redundant packet.

[0187] Aspect 14: A method of any of Aspects 1-13, wherein the UE is capable of operating solely based on the RLC-UM for a multicast message or a broadcast message, the method further comprising: receiving a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for a network decoding feature or a forward error correction feature; and discarding the packet at least in part based on the fact that the packet is a retransmission or redundant packet for the network decoding feature or the forward error correction feature.

[0188] Aspect 15: A method of any of Aspects 1-14, wherein the UE is capable of operating according to the RLC-AM or the RLC-UM for a multicast message or a broadcast message, the method further comprising: receiving a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for a network decoding feature or a forward error correction feature; and decoding the packet at least in part based on the indication that the packet is a retransmission or redundant packet for the network decoding feature or the forward error correction feature.

[0189] Aspect 16: A method of performing wireless communication by a base station, comprising: generating a multicast message or a broadcast message using a Radio Link Control (RLC) format associated with an RLC Acknowledgment Mode (RLC-AM); and transmitting the multicast message or the broadcast message using the RLC format associated with the RLC-AM, wherein transmitting the multicast message or the broadcast message enables a first User Equipment (UE) to operate according to the RLC-AM for the multicast or broadcast message, and enables a second UE to operate according to an RLC Unacknowledgment Mode (RLC-UM) for the multicast or broadcast message.

[0190] Aspect 17: The method of aspect 16, wherein the first UE is capable of operating in the RLC-AM or the RLC-UM for multicast messages or broadcast messages, and the second UE is capable of operating only in the RLC-UM for multicast messages or broadcast messages.

[0191] Aspect 18: The method of any of Aspects 16-17, wherein transmitting the multicast message or the broadcast message enables the second UE to operate according to the RLC-UM, at least in part, based on ignoring one or more fields associated with the RLC-AM included in the multicast message or the broadcast message.

[0192] Aspect 19: The method of any of Aspects 16-18 further includes transmitting a Radio Resource Control (RRC) message indicating that the RLC-AM is to be used for multicast or broadcast messages, wherein transmitting the RRC message configures the first UE to operate according to the RLC-AM and enables the second UE to identify that the base station is to use the RLC format associated with the RLC-AM.

[0193] Aspect 20: A method of any of Aspects 16-19, wherein the RLC format associated with the RLC-AM is an RLC Packet Data Unit (PDU) format for multicast or broadcast radio bearers (MRB), and wherein transmitting the multicast message or the broadcast message includes transmitting the multicast message or the broadcast message using the RLC PDU format for the MRB, and including one or more reserved fields in the header of the multicast message or the broadcast message, or one or more fields associated with the RLC-AM.

[0194] Aspect 21: The method of aspect 20, wherein transmitting the multicast message or the broadcast message includes transmitting the multicast message or the broadcast message in at least one of the one or more reserved fields that includes an indication that the RLC-AM is to be used for the multicast message or the broadcast message, wherein including the indication in at least one of the one or more reserved fields enables the first UE to operate in the RLC-AM for the multicast message or the broadcast message.

[0195] Aspect 22: The method of any of Aspects 16-21 further includes transmitting a packet associated with the multicast message or the broadcast message, the packet including a field indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features.

[0196] Aspect 23: The method of any of Aspects 16-22 further includes transmitting a packet associated with the multicast message or the broadcast message, the packet using a Packet Data Convergence Protocol (PDCP) Packet Data Unit (PDU) format associated with redundant packets used for network decoding features or forward error correction features.

[0197] Aspect 24: The method of aspect 23, wherein transmitting the packet includes transmitting the packet including a field indicating a range of PDCP sequence numbers associated with the packet or a control PDU type (CPT) field indicating that the packet is a redundant packet.

[0198] Aspect 25: The method of any of Aspects 16-24 further includes transmitting a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features, and wherein indicating that the packet is a retransmission or redundant packet enables the first UE to decode the packet and operate in the RLC-AM, and enables the second UE to discard the packet and operate in the RLC-UM.

[0199] Aspect 26: An apparatus for wireless communication at a device, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform methods as described in one or more of aspects 1-15.

[0200] Aspect 27: An apparatus for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors being configured to perform methods as described in one or more aspects of aspects 1-15.

[0201] Aspect 28: An apparatus for wireless communication, comprising at least one means for performing a method as described in one or more aspects of aspects 1-15.

[0202] Aspect 29: A non-transient computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform methods as described in one or more aspects of aspects 1-15.

[0203] Aspect 30: A non-transient computer-readable medium storing a set of instructions for wireless communication, the set of instructions including one or more instructions which, when executed by one or more processors of a device, cause the device to perform methods as described in one or more aspects of aspects 1-15.

[0204] Aspect 31: An apparatus for wireless communication at a device, comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform methods as described in one or more of aspects 15-25.

[0205] Aspect 32: An apparatus for wireless communication, comprising a memory and one or more processors coupled to the memory, the memory and the one or more processors being configured to perform methods as described in one or more aspects of aspects 15-25.

[0206] Aspect 33: An apparatus for wireless communication, comprising at least one means for performing a method as described in one or more aspects of aspects 15-25.

[0207] Aspect 34: A non-transient computer-readable medium storing code for wireless communication, the code including instructions executable by a processor to perform methods as described in one or more aspects of aspects 15-25.

[0208] Aspect 35: A non-transient computer-readable medium storing a set of instructions for wireless communication, the set of instructions including one or more instructions which, when executed by one or more processors of a device, cause the device to perform methods as described in one or more aspects of aspects 15-25.

[0209] The foregoing disclosure provides explanations and descriptions, 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 foregoing disclosure or may be obtained through practice.

[0210] As used herein, the term "component" is intended to be interpreted broadly as hardware, firmware, or a combination of hardware and software. As used herein, a processor is implemented using hardware, firmware, or a combination of hardware and software. It will be apparent that the systems or methods described herein can be implemented in various forms as hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems or methods is not limited in any aspect. Thus, the operation and behavior of these systems or methods are described herein without reference to any specific software code—it is understood that software and hardware may be designed to implement these systems or methods, at least in part, based on the descriptions herein.

[0211] As used in this article, depending on the context, a threshold can refer to a value greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0212] Although specific combinations of features are described in the claims or disclosed in the specification, these combinations are not intended to limit the disclosure of aspects. In fact, many of these features can be combined in ways not specifically described in the claims or disclosed in the specification. Although each dependent claim listed below may be directly subordinated to only one claim, the disclosure of aspects includes each dependent claim being combined with each other claim in this set of claims. As used herein, the phrase “at least one of” refers to any combination of these items, including single members. As an example, “at least one of a, b, or c” is intended to cover: a, b, c, ab, ac, bc, and abc, as well as any combination having multiple identical elements (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0213] The elements, actions, or instructions used herein should not be construed as critical or necessary unless explicitly stated otherwise. Furthermore, as used herein, the articles “a” and “a certain” are intended to include one or more items and may be used interchangeably with “one or more.” Additionally, as used herein, the article “the” is intended to include one or more items referenced in conjunction with the article “the” and may be used interchangeably with “one or more.” Furthermore, as used herein, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, or a combination of related and unrelated items) and may be used interchangeably with “one or more.” Where only one item is intended, the phrase “only one” or similar language is used. Moreover, as used herein, the terms “having,” “containing,” “including,” and similar terms are intended to be open-ended terms. Additionally, the phrase “based on” is intended to mean “at least partially based on” unless otherwise explicitly stated. Moreover, as used herein, the term “or” is intended to be inclusive when used in a sequence and may be used interchangeably with “and / or” unless otherwise explicitly stated (e.g., in combination with “either of” or “only one of”).

Claims

1. A user equipment (UE) for wireless communication, comprising: At least one processor; as well as At least one memory communicatively coupled to and storing processor-readable code, which, when executed by the at least one processor, is configured to cause the UE to: Receive multicast or broadcast messages from the base station using the RLC format associated with Radio Link Control (RLC) Acknowledgment Mode (RLC-AM); The UE's ability to decode the multicast message or broadcast message to identify information associated with the RLC Unacknowledged Mode (RLC-UM) is at least partially based on the UE's capabilities. as well as The operation is based at least in part on decoding the multicast message or the broadcast message in accordance with the RLC-UM.

2. The UE of claim 1, wherein the UE supports the RLC format associated with the RLC-AM and different RLC formats associated with the RLC-UM, and wherein the UE is capable of operating only according to the RLC-UM used for multicast messages or broadcast messages.

3. The UE of claim 1, wherein the UE only supports the RLC format associated with the RLC-AM, and wherein the UE is capable of operating only according to the RLC-UM used for multicast messages or broadcast messages.

4. The UE of claim 1, wherein the processor-readable code is further configured, when executed by the at least one processor to decode the multicast message or the broadcast message, to cause the UE to: Identify one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM; and The multicast message or broadcast message is decoded at least in part based on extracting information associated with the RLC-UM from one or more other fields of the multicast message or broadcast message and ignoring the one or more fields associated with the RLC-AM.

5. The UE of claim 1, wherein the processor-readable code, when executed by the at least one processor to operate according to the RLC-UM, is further configured to cause the UE to operate according to the RLC-UM at least in part based on extracting the information associated with the RLC-UM from one or more fields of the multicast message or the broadcast message.

6. The UE of claim 1, wherein the UE is capable of operating according to the RLC-AM or the RLC-UM for multicast or broadcast messages, wherein the processor-readable code, when executed by the at least one processor, is further configured to cause the UE to receive a Radio Resource Control (RRC) configuration instructing the UE to operate according to the RLC-UM for multicast or broadcast messages, and The processor-readable code therein, when executed by the at least one processor to decode the multicast message or the broadcast message, is further configured to cause the UE to decode the multicast message or the broadcast message at least in part based on extracting information associated with the RLC-UM from one or more other fields of the multicast message or the broadcast message and ignoring the one or more fields associated with the RLC-AM.

7. The UE of claim 1, wherein the processor-readable code, when executed by the at least one processor, is further configured to cause the UE to receive from the base station a Radio Resource Control (RRC) configuration indicating whether the RLC-AM is to be used for multicast or broadcast messages. The processor-readable code, when executed by the at least one processor to decode the multicast message or the broadcast message, is further configured to cause the UE to decode the multicast message or the broadcast message at least in part based on the RRC configuration received instructing the base station to use the RLC format associated with the RLC-AM. The processor-readable code therein, when executed by the at least one processor to operate according to the RLC-UM, is further configured to cause the UE to operate according to the RLC-UM at least in part based on decoding the multicast message or the broadcast message.

8. The UE of claim 1, wherein the processor-readable code, when executed by the at least one processor, is further configured to cause the UE to receive from the base station a Radio Resource Control (RRC) configuration indicating whether the RLC-AM is to be used for multicast or broadcast messages; and The processor-readable code therein, when executed by the at least one processor to decode the multicast message or the broadcast message, is further configured to cause the UE to decode the multicast message or the broadcast message at least in part based on ignoring one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM.

9. The UE of claim 1, wherein the RLC format associated with the RLC-AM is an RLC Packet Data Unit (PDU) format for multicast or broadcast radio bearers (MRB), and wherein the processor-readable code, when executed by the at least one processor to receive the multicast message or the broadcast message, is further configured to cause the UE to receive the multicast message or the broadcast message using the RLC PDU format for the MRB, and including one or more reserved fields or one or more fields associated with the RLC-AM in the header of the multicast message or the broadcast message.

10. The UE of claim 9, wherein the processor-readable code, when executed by the at least one processor to decode the multicast message or the broadcast message, is further configured to cause the UE to decode the multicast message or the broadcast message at least in part based on ignoring the one or more reserved fields or the one or more fields associated with the RLC-AM.

11. The UE of claim 1, wherein the processor-readable code, when executed by the at least one processor, is further configured to cause the UE to receive packets associated with the multicast message or the broadcast message, the packets including a field indicating that the packets are retransmission or redundant packets for network decoding features or forward error correction features.

12. The UE of claim 1, wherein the processor-readable code, when executed by the at least one processor, is further configured to cause the UE to receive packets associated with the multicast message or the broadcast message, the packets using a Packet Data Convergence Protocol (PDCP) Packet Data Unit (PDU) format associated with redundant packets for network decoding features or forward error correction features.

13. The UE of claim 12, wherein the processor-readable code, when executed by the at least one processor to receive the packet, is further configured to cause the UE to receive the packet including a field indicating a range of PDCP sequence numbers associated with the packet or a control PDU type (CPT) field indicating that the packet is a redundant packet.

14. The UE of claim 1, wherein the UE is capable of operating solely based on the RLC-UM for multicast or broadcast messages, wherein the processor-readable code, when executed by the at least one processor, is further configured to cause the UE to: Receive a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features; and The packet is discarded at least in part because it is a retransmission or redundant packet used for the network decoding feature or the forward error correction feature.

15. The UE of claim 1, wherein the UE is capable of operating according to the RLC-AM or the RLC-UM for multicast messages or broadcast messages, wherein the processor-readable code, when executed by the at least one processor, is further configured to cause the UE to: Receive a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features; and The packet is decoded at least in part based on the indication that the packet is a retransmission or redundant packet for the network decoding feature or the forward error correction feature.

16. A wireless communication method performed by a user equipment (UE), comprising: Receive multicast or broadcast messages from the base station using the RLC format associated with Radio Link Control (RLC) Acknowledgment Mode (RLC-AM); The UE's ability to decode the multicast message or broadcast message to identify information associated with the RLC Unacknowledged Mode (RLC-UM) is at least partially based on the UE's capabilities. as well as The operation is based at least in part on decoding the multicast message or the broadcast message in accordance with the RLC-UM.

17. The method of claim 16, wherein the UE supports the RLC format associated with the RLC-AM and different RLC formats associated with the RLC-UM, and wherein the UE is capable of operating only according to the RLC-UM used for multicast messages or broadcast messages.

18. The method of claim 16, wherein the UE only supports the RLC format associated with the RLC-AM, and wherein the UE is capable of operating only according to the RLC-UM for multicast messages or broadcast messages.

19. The method of claim 16, wherein decoding the multicast message or the broadcast message comprises: Identify one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM; as well as The multicast message or broadcast message is decoded at least in part based on extracting information associated with the RLC-UM from one or more other fields of the multicast message or broadcast message and ignoring the one or more fields associated with the RLC-AM.

20. The method of claim 16, wherein operating according to the RLC-UM comprises operating according to the RLC-UM based at least in part on extracting the information associated with the RLC-UM from one or more fields of the multicast message or the broadcast message.

21. The method of claim 16, wherein the UE is capable of operating according to the RLC-AM or the RLC-UM for multicast or broadcast messages, the method further comprising receiving a Radio Resource Control (RRC) configuration instructing the UE to operate according to the RLC-UM for multicast or broadcast messages. Decoding the multicast message or the broadcast message includes at least in part based on extracting information associated with the RLC-UM from one or more other fields of the multicast message or the broadcast message and ignoring the one or more fields associated with the RLC-AM.

22. The method of claim 16, further comprising: Receive from the base station a Radio Resource Control (RRC) configuration indicating whether the RLC-AM should be used for multicast or broadcast messages. Decoding the multicast message or the broadcast message includes at least in part based on receiving the RRC configuration instructing the base station to use the RLC format associated with the RLC-AM to decode the multicast message or the broadcast message, and Operating according to the RLC-UM includes operating according to the RLC-UM at least in part based on decoding the multicast message or the broadcast message.

23. The method of claim 16, further comprising receiving from the base station a Radio Resource Control (RRC) configuration indicating that the RLC-AM is to be used for multicast or broadcast messages; and Decoding the multicast message or the broadcast message includes decoding the multicast message or the broadcast message based at least in part on ignoring one or more fields in the multicast message or the broadcast message that are associated with the RLC-AM.

24. The method of claim 16, wherein the RLC format associated with the RLC-AM is an RLC Packet Data Unit (PDU) format for multicast or broadcast radio bearers (MRB), and wherein receiving the multicast message or the broadcast message includes receiving the multicast message or the broadcast message using the RLC PDU format for the MRB, and including one or more reserved fields in the header of the multicast message or the broadcast message, or one or more fields associated with the RLC-AM.

25. The method of claim 24, wherein decoding the multicast message or the broadcast message comprises decoding the multicast message or the broadcast message at least in part based on ignoring the one or more reserved fields or the one or more fields associated with the RLC-AM.

26. The method of claim 16, further comprising receiving a packet associated with the multicast message or the broadcast message, the packet including a field indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features.

27. The method of claim 16, further comprising receiving a packet associated with the multicast message or the broadcast message, the packet using a Packet Data Convergence Protocol (PDCP) Packet Data Unit (PDU) format associated with redundant packets used for network decoding features or forward error correction features.

28. The method of claim 27, wherein receiving the packet includes receiving the packet including a field indicating a range of PDCP sequence numbers associated with the packet or a control PDU type (CPT) field indicating that the packet is a redundant packet.

29. The method of claim 16, wherein the UE is capable of operating solely based on the RLC-UM used for multicast or broadcast messages, the method further comprising: Receive a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features; and The packet is discarded at least in part because it is a retransmission or redundant packet used for the network decoding feature or the forward error correction feature.

30. The method of claim 16, wherein the UE is capable of operating according to the RLC-AM or the RLC-UM for multicast messages or broadcast messages, the method further comprising: Receive a packet associated with the multicast message or the broadcast message, the packet indicating that the packet is a retransmission or redundant packet for network decoding features or forward error correction features; and The packet is decoded at least in part based on the indication that the packet is a retransmission or redundant packet for the network decoding feature or the forward error correction feature.

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