Method and apparatus for selecting radio bearer mode for multicast broadcast service

Abstract

The present disclosure describes methods, systems, and devices for selecting radio bearer mode for multicast broadcast service (MBS). The method includes notifying a radio access network (RAN) that a user equipment (UE) is receiving / interested in receiving or no longer receiving / no longer interested in receiving a multicast broadcast service (MBS) service via a transmission mode. The method includes transmitting, by the UE to the RAN, MBS interest information, the MBS interest information including a list of MBS services of interest.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to wireless communications. In particular, the present disclosure relates to methods and apparatuses for selecting a radio bearer mode for multicast broadcast services (MBS). BACKGROUND

[0002] Wireless communication technology is pushing the world towards an increasingly interconnected and networked society. High speed and low latency wireless communications rely on efficient network resource management and allocation between user equipment and wireless access network nodes, including but not limited to radio access networks (RANs). A RAN can communicate with one or more user equipment (UEs) using a radio bearer (RB) for multicast broadcast services (MBS). The radio bearer can be a point-to-point (PTP) radio bearer or a point-to-multipoint (PTM) radio bearer. The present disclosure can address problems and / or challenges of determining which radio bearer to implement for high speed and efficient wireless communications between a RAN and one or more UEs. SUMMARY

[0003] The present application relates to methods, systems, and apparatuses for wireless communications, and more specifically, to methods, systems, and apparatuses for selecting a radio bearer mode for multicast broadcast services (MBS).

[0004] In one embodiment, the present disclosure describes a method for wireless communications. The method includes notifying a radio access network (RAN) that a user equipment (UE) is receiving / is interested in receiving or is no longer receiving / is no longer interested in receiving a multicast broadcast service (MBS) service via a transmission mode. The method includes transmitting, by the UE to the RAN, MBS interest information including a list of MBS services of interest.

[0005] In another embodiment, the present disclosure describes a method for wireless communications. The method includes transmitting, by a core network (CN) to a radio access network (RAN), multicast broadcast service (MBS) session management information including at least one of: a MBS session identification, a list of MBS service identification information associated with the MBS session, a list of quality of service (QoS) flow identifications associated with the MBS session, a list of user equipment (UE) identifications joining the MBS session.

[0006] In another embodiment, the disclosure describes a method for wireless communication. The method includes transmitting, by a next generation radio access network node distributed unit (gNB-DU) to a gNB centralized unit (gNB-CU), multicast broadcast service (MBS) resource status information to inform the gNB-CU about a resource status in the gNB-DU for a MBS service.

[0007] In another embodiment, the disclosure describes a method for wireless communication. The method includes transmitting, by a next generation radio access network node distributed unit (gNB-DU) to a gNB centralized unit (gNB-CU), multicast broadcast service (MBS) notification information to inform the gNB-CU that a quality of service (QoS) of an already established guaranteed bit rate (GBR) radio bearer (RB) associated with a MBS session can no longer be satisfied or can be satisfied again.

[0008] In some other embodiments, an apparatus for wireless communication can include a memory that stores instructions and a processing circuitry in communication with the memory. When the processing circuitry executes the instructions, the processing circuitry is configured to perform the above-described methods.

[0009] In some other embodiments, an apparatus for wireless communication can include a memory that stores instructions and a processing circuitry in communication with the memory. When the processing circuitry executes the instructions, the processing circuitry is configured to perform the above-described methods.

[0010] In some other embodiments, a computer readable medium includes instructions that, when executed by a computer, cause the computer to perform the above-described methods.

[0011] The above and other aspects and implementations are described in more detail in the drawings, descriptions and claims. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1A An example of a point-to-point (PTP) radio bearer in a wireless communication system is shown.

[0013] Figure 1B An example of a point-to-multipoint (PTM) radio bearer in a wireless communication system is shown.

[0014] Figure 2 An example of a wireless network node is shown.

[0015] Figure 3 An example of a user equipment is shown.

[0016] Figure 4 A flowchart of a method for wireless communication is shown.

[0017] Figure 5 An example of a flowchart of a method for wireless communication is shown.Figure 4 An exemplary logic flow for a method used in wireless communication.

[0018] Figure 6 A flowchart of another method for wireless communication is shown.

[0019] Figure 7 It shows Figure 6 An exemplary logic flow for a method used in wireless communication.

[0020] Figure 8 A flowchart of another method for wireless communication is shown.

[0021] Figure 9 It shows Figure 8 An exemplary logic flow for a method used in wireless communication.

[0022] Figure 10 A flowchart of another method for wireless communication is shown.

[0023] Figure 11 It shows Figure 10 An exemplary logic flow for a method used in wireless communication. Detailed Implementation

[0024] This disclosure will now be described in detail below with reference to the accompanying drawings, which form part of this disclosure and illustrate specific examples of embodiments by way of illustration. However, it should be noted that this disclosure may be embodied in various different forms, and therefore the subject matter covered or claimed is intended to be construed as not being limited to any of the embodiments set forth below.

[0025] Throughout this specification and claims, terms may have subtle meanings implied or suggested by the context, in addition to their explicitly stated meanings. Similarly, the phrases “in one embodiment” or “in some embodiments” as used herein do not necessarily refer to the same embodiment, and the phrases “in another embodiment” or “in other embodiments” as used herein do not necessarily refer to different embodiments. For example, the claimed subject matter is intended to include all or part of the exemplary embodiments or combinations of embodiments.

[0026] Generally, terms can be understood, at least in part, based on their usage in the context. For example, terms such as “and,” “or,” and “and / or,” as used herein, can come in a variety of meanings, which can depend at least in part on the context in which they are used. Typically, if “or” is used to relate a list such as A, B, or C, it is intended to mean A, B, and C in an inclusive sense, and A, B, or C in an exclusive sense. Additionally, terms such as “one or more” or “at least one,” as used herein (depending at least in part on the context), can be used to describe any feature, structure, or characteristic in a singular sense, or can be used to describe a combination of features, structures, or characteristics in a plural sense. Similarly, terms such as “a,” “an,” or “the” can be understood to convey either a singular or a plural usage, depending at least in part on the context. Furthermore, the terms “based on” or “determined by” can be understood not necessarily to convey a set of exclusive factors, but may allow for the presence of additional factors that are not necessarily explicitly described, again depending at least in part on the context.

[0027] This disclosure describes methods and apparatus for selecting a radio bearer mode for multicast broadcast services (MBS).

[0028] Next-generation (NR) or fifth-generation (5G) wireless communication can provide a range of capabilities, from high-speed downloads to supporting real-time, low-latency communication. Wireless communication can use radio bearers (RBs) for multicast broadcast services (MBS). This range of capabilities may require quality of service (QoS) characteristics such as latency, error rate, and priority. In NR wireless communication, one or more service data streams with the same QoS characteristics can be combined into a single QoS stream. Each QoS stream can be identified by a QoS stream identifier, which informs network components of the corresponding characteristics of the QoS stream.

[0029] Figure 1A and Figure 1B Various transmission modes for a wireless communication system 100 are illustrated, including a core network (CN) 110, a radio access network (RAN) 130, and one or more user equipments (UEs) (152, 154, and 156). RAN 130 may include a wireless network base station, or an NG radio access network (NG-RAN) base station or node, which may include a nodeB (NB, e.g., gNB) in a mobile telecommunications environment. In one embodiment, core network 110 may include a 5G core network (5GC), and interface 125 may include an NG interface. RAN 130 (e.g., gNB) may include an architecture that separates central units (CUs) from one or more distributed units (DUs).

[0030] Communications between the RAN and one or more UEs can include at least one radio bearer (RB) for multicast broadcast service (MBS). The UEs can use two different transmission modes for receiving MBS data over the RB. One transmission mode can be point-to-point (PTP) or unicast, and the other transmission mode can be point-to-multipoint (PTM) or groupcast or broadcast. The PTP transmission mode and the unicast transmission mode can refer to the same transmission mode. The PTP RB can be a DRB, and the PTM RB can be a groupcast RB or a broadcast RB. Figure 1A A PTP transmission mode for one or more UEs for MBS is shown; Figure 1B A PTM transmission mode for one or more UEs for MBS is shown.

[0031] Referring to Figure 1A The first UE 152 can wirelessly receive communications from the RAN 130 via the PTP RB 142 and wirelessly transmit communications to the RAN 130 via the uplink channel 141. Likewise, the second UE 154 can wirelessly receive communications from the RAN 130 via the PTP RB 144 and wirelessly transmit communications to the RAN 130 via the uplink channel 143; and the third UE 156 can wirelessly receive communications from the RAN 130 via the PTP RB 146 and wirelessly transmit communications to the RAN 130 via the uplink channel 145.

[0032] Referring to Figure 1B The RAN 130 can wirelessly communicate with one or more UEs (152, 154, and 156) via the PTM RB 160. In one implementation, the first UE 152 can wirelessly transmit communications to the RAN 130 via the uplink channel 161. Likewise, the second UE 154 can wirelessly transmit communications to the RAN 130 via the uplink channel 163; and the third UE 156 can wirelessly transmit communications to the RAN 130 via the uplink channel 165.

[0033] In Figure 1A and Figure 1BIn the wireless communication system 100, the RAN 130 can select which transmission mode for MBS a UE uses in order to improve the efficiency of the wireless network. The transmission mode selection can depend on various types of information, such as, but not limited to: the load situation of the MBS, the UE’s working status in PTP transmission mode or PTM transmission mode, or the UE’s transmission mode interest indication. There are some issues associated with selecting which transmission mode for MBS, for example, how the UE sends the UE’s interested transmission mode for MBS to the RAN. The present disclosure describes embodiments of methods and apparatuses for selecting radio bearer mode for MBS, which solve at least one of the issues discussed above.

[0034] Figure 2 An example wireless access network or wireless communication base station 200 is shown. The base station 200 can include wireless transmit / receive (Tx / Rx) circuitry 208 to transmit / receive communications with one or more UEs and / or one or more other base stations. The base station can also include network interface circuitry 209 to enable the base station to communicate (e.g., optical or wired interconnections, Ethernet and / or other data transmission media / protocols) with other base stations and / or a core network. The base station 200 can optionally include input / output (I / O) interface 206 to communicate with operators or such personnel.

[0035] The base station can also include system circuitry 204. The system circuitry 204 can include one or more processors 221 and / or memory 222. The memory 222 can include an operating system 224, instructions 226, and parameters 228. The instructions 226 can be configured for the one or more processors 124 to perform the functions of the base station. The parameters 228 can include parameters to support the execution of the instructions 226. For example, the parameters can include network protocol settings, bandwidth parameters, radio frequency mapping allocations, and / or other parameters.

[0036] Figure 3An example user equipment (UE) 300 is shown. The UE 300 can be a mobile device (e.g., a smartphone or a mobile communication module disposed in a vehicle). The UE 300 can include a communication interface 302, a system circuit 304, an input / output interface (I / O) 306, a display circuit 308, and a storage device 309. The display circuit can include a user interface 310. The system circuit 304 can include any combination of hardware, software, firmware, or other logic / circuitry. The system circuit 304 can be implemented with, for example, one or more system on a chip (SoC), application specific integrated circuits (ASICs), discrete analog and digital circuits, and other circuitry. The system circuit 304 can be part of an implementation of any desired functionality in the UE 300. In this regard, the system circuit 304 can include logic that facilitates example decoding and playing of music and videos (e.g., MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback); running applications; accepting user input; saving and retrieving application data; establishing, maintaining, and terminating cellular telephone calls or data connections for, e.g., internet connectivity; establishing, maintaining, and terminating wireless network connections, Bluetooth connections, or other connections; and displaying relevant information on the user interface 310. The user interface 310 and the input / output (I / O) interface 306 can include a graphical user interface, a touch-sensitive display, tactile feedback or other haptic output, voice or facial recognition input, buttons, switches, a speaker, and other user interface elements. Additional examples of the I / O interface 306 can include a microphone, a video and still image camera, a temperature sensor, a vibration sensor, a rotation and direction sensor, earphone and microphone input / output jacks, a universal serial bus (USB) connector, a memory card slot, a radiation sensor (e.g., an IR sensor), and other types of input.

[0037] Referring to Figure 3The communication interface 302 can include radio frequency (RF) transmit (Tx) and receive (Rx) circuitry 316 that handles transmission and reception of signals via one or more antennas 314. The communication interface 302 can include one or more transceivers. The transceiver can be a wireless transceiver that includes modulation / demodulation circuitry, digital to analog converters (DACs), shaping tables, analog to digital converters (ADCs), filters, wave shapers, pre-amplifiers, power amplifiers, and / or other logic used to transmit and receive via one or more antennas or, for some devices, via physical (e.g., wired) media. The transmitted signals and received signals can follow any of a variety of formats, protocols, modulation (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM), frequency channels, code rates, and encodings. As one specific example, the communication interface 302 can include a transceiver that supports transmission and reception under the 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High Speed Packet Access (HSPA)+, 4G / Long Term Evolution (LTE), and 5G standards. However, the techniques described below are applicable to other wireless communication technologies whether derived from the Third Generation Partnership Project (3GPP), GSM Association, 3GPP2, IEEE, or other partnership or standards body.

[0038] Referring to Figure 3 The system circuitry 304 can include one or more processors 321 and memory 322. The memory 322 stores, for example, an operating system 324, instructions 326, and parameters 328. The processor 321 is configured to execute the instructions 326 to carry out the desired functionality for the UE 300. The parameters 328 can provide and specify configuration and operational options for the instructions 326. The memory 322 can also store any BT, WiFi, 3G, 4G, 5G, or other data that the UE 300 will transmit through or has received through the communication interface 302. In various implementations, system power for the UE 300 can be provided by a power storage device such as a battery or a transformer.

[0039] The present disclosure describes several embodiments of methods and apparatuses for selecting a radio bearer mode for a multicast broadcast service (MBS), which can be implemented in part or in whole on the wireless network base stations and / or user equipment described in the above Figure 2 and Figure 3

[0040] In one embodiment, referring to Figure 4 ​A method 400 for wireless communication includes using multicast broadcast service (MBS) interest information to inform a radio access network (RAN) that a user equipment (UE) is receiving / interested in receiving or no longer receiving / no longer interested in receiving a MBS service via a transmission mode. The method 400 can include a step 410 of transmitting, by the UE to the RAN, MBS interest information including a list of MBS services of interest. The MBS interest information can be carried in a radio resource control (RRC) message. The method 400 can inform the RAN of the UE’s interest in using a PTP transmission mode and / or a PTM transmission mode.

[0041] In an embodiment, the MBS interest information further includes a transmission mode interest indication for each item in the list of MBS services of interest, the transmission mode interest indication indicating a transmission mode of interest to the UE for receiving the corresponding MBS service.

[0042] In another embodiment, the MBS interest information further includes a transmission mode interest indication for the UE, the transmission mode interest indication indicating a transmission mode of interest to the UE for receiving all MBS services of interest.

[0043] In another embodiment, the MBS interest information further includes at least one transmission mode interest indication, each transmission mode interest indication corresponding to a subset of the list of MBS services of interest, the transmission mode interest indication indicating a transmission mode of interest to the UE for receiving the corresponding MBS service.

[0044] Optimally, the trigger condition for transmitting the MBS interest information includes when the transmission mode interest changes. The trigger condition for transmitting the MBS interest information includes at least one of the following: when the transmission mode interest changes, when the connection establishment is successful, when entering or leaving a service area, when a MBS session starts or stops, when the interest changes, when a priority changes between MBMS reception and unicast reception, when a PCell broadcast system information changes regarding a service area identification.

[0045] As Figure 5As shown, in one implementation, the UE 502 can receive system information containing MBS service area identities (SAIs) of current and / or neighboring carrier frequencies prior to sending the RRC message. In another implementation, the list of MBS services of interest can include at least one of: one or more MBS services that the UE is currently receiving, and / or one or more MBS services that the UE is interested in receiving and is about to start. In another implementation, each item in the list of MBS services of interest can include at least one of: an MBS service identity, a set of quality of service (QoS) flow identities, an IP multicast address, an IP source address, or an MBS session identity. For example, but not limited to, the MBS service identity can include a temporary mobile group identity (TMGI).

[0046] The transmission mode interest indication can include a first value indicating that the UE is interested in using a point-to-point (PTP) transmission mode for one or more respective MBS services of interest. For example, but not limited to, the first value can include PTP.

[0047] The transmission mode interest indication can include a second value indicating that the UE is interested in using a point-to-multipoint (PTM) transmission mode for one or more respective MBS services. For example, but not limited to, the second value can include PTM.

[0048] The transmission mode interest indication can include a third value indicating that the UE is interested in using either a PTP transmission mode or a PTM transmission mode for one or more respective MBS services, and optionally, the PTP transmission mode has a higher priority than the PTM transmission mode. For example, but not limited to, the third value can include <PTP, PTM>.

[0049] The transmission mode interest indication can include a fourth value indicating that the UE is interested in using either a PTP transmission mode or a PTM transmission mode for one or more respective MBS services, and optionally, the PTM transmission mode has a higher priority than the PTP transmission mode. For example, but not limited to, the fourth value can include <PTM, PTP>.

[0050] The transmission mode interest indication can include a fifth value indicating that the UE has no interest in using either a PTP transmission mode or a PTM transmission mode for one or more respective MBS services of interest. For example, but not limited to, the fifth value can include a blank.

[0051] The transmission mode interest indication can comprise a sixth value, the transmission mode interest indication indicating that the UE is interested in using both PTP transmission mode and PTM transmission mode simultaneously for one or more corresponding interested MBS services. For example but not limiting, the sixth value can comprise <PTM+PTP>.

[0052] In another embodiment, referring to Figure 6 A method 600 for wireless communication includes using non-access stratum (NAS) messages and next generation application protocol (NGAP) messages to select a radio bearer mode for multicast broadcast service (MBS) from a user equipment (UE) to a radio access network (RAN). The method 600 can include some or all of the following steps: step 610: sending, by a user equipment (UE), MBS service request information to a core network (CN), the MBS service request information comprising MBS service identification information corresponding to a requested MBS service and a transmission mode interest indication indicating a transmission mode that the UE is interested in for receiving the MBS service; and step 620: sending, by the core network (CN), multicast broadcast service (MBS) session management information to a radio access network (RAN). The MBS session management information can be MBS session start information, or MBS session update information, or MBS session setup information, or MBS session modification information. The MBS session management information can comprise at least one of the following: a MBS session identification, a list of MBS service identification information associated with the MBS session identification, a list of quality of service (QoS) flow identification associated with the MBS session, a list of user equipment (UE) identification joining the MBS session.

[0053] Figure 7 An example logical flow of a method 700 for using non-access stratum (NAS) messages and next generation application protocol (NGAP) messages to indicate a transmission mode for a user equipment (UE) 702 from a core network (CN) 706 to a radio access network (RAN) 704 for multicast broadcast service (MBS) is shown. The RAN 704 can comprise a gNB-CU. The CN can comprise an AMF.

[0054] The method 700 can comprise a step 710 of transmitting, by the UE 702, a NAS message to the CN 706. The NAS message can comprise MBS service request information, which can comprise MBS service identification information corresponding to a requested MBS service identification information and a transmission mode interest indication indicating a transmission mode of interest to the UE for receiving a corresponding MBS service. In an embodiment, the MBS service identification information can comprise at least one of: a MBS service identification, a MBS session identification, and a set of quality of service (QoS) flow identifications, a MBS session identification, an IP multicast address, an IP source address, and a TMGI.

[0055] The method 700 can further comprise a step 720 of transmitting, by the CN 706, a NGAP message to the RAN 704. The NGAP message can comprise MBS session management information. The MBS session management information can be MBS session start information, or MBS session update information, or MBS session setup information, or MBS session modification information. In an embodiment, the MBS session management information can comprise at least one of: a MBS service identification or a list of MBS service identifications associated with a MBS session, a MBS session identification, a list of quality of service (QoS) flow identifications, a list of UE identifications joining the MBS session.

[0056] The MBS session management information can comprise a transmission mode indication indicating a transmission mode of interest to the UE for receiving a corresponding one or more MBS services, and / or a transmission mode indication indicating a transmission mode determined by the CN for the UE to receive a corresponding one or more MBS services. In an embodiment, the MBS session management information further comprises a transmission mode indication for each of the list of UE identifications. In another embodiment, the MBS session management information further comprises a transmission mode indication for each of the list of UE identifications for each of the list of MBS service identification information. In another embodiment, the MBS session management information further comprises at least one transmission mode indication, each transmission mode interest indicating a subset of the list of MBS services of interest.

[0057] The transmission mode indication or the transmission mode interest indication can comprise a first value indicating that a point-to-point (PTP) transmission mode is determined by the CN for the UE, or the point-to-point (PTP) transmission mode is of interest to the UE for one or more corresponding MBS services of interest. For example, but not limited to, the first value can comprise PTP.

[0058] The transmission mode indication or the transmission mode interest indication can comprise a second value, the transmission mode interest indication indicating that a point-to-multipoint (PTM) transmission mode is decided by the CN for the UE or the point-to-multipoint (PTM) transmission mode is of interest to the UE for one or more respective MBS services. For example, but not limited to, the second value can comprise PTM.

[0059] The transmission mode indication or the transmission mode interest indication can comprise a third value, the transmission mode interest indication indicating that a PTP transmission mode and / or a PTM transmission mode is decided by the CN for the UE or the PTP transmission mode and / or the PTM transmission mode is of interest to the UE for one or more respective MBS services, and optionally, the PTP transmission mode has a higher priority than the PTM transmission mode. For example, but not limited to, the third value can comprise <PTP, PTM>.

[0060] The transmission mode indication or the transmission mode interest indication can comprise a fourth value, the transmission mode interest indication indicating that a PTP transmission mode and / or a PTM transmission mode is decided by the CN for the UE or the PTP transmission mode and / or the PTM transmission mode is of interest to the UE for one or more respective MBS services, and optionally, the PTM transmission mode has a higher priority than the PTP transmission mode. For example, but not limited to, the fourth value can comprise <PTM, PTP>.

[0061] The transmission mode indication or the transmission mode interest indication can comprise a fifth value, the transmission mode interest indication indicating that no transmission mode is decided by the CN for the UE or no transmission mode is of interest to the UE for one or more respective MBS services of interest. For example, but not limited to, the fifth value can comprise a blank.

[0062] The transmission mode indication or the transmission mode interest indication can comprise a sixth value, the transmission mode interest indication indicating that a PTP transmission mode and a PTM transmission mode is decided by the CN for the UE or the PTP transmission mode and the PTM transmission mode is of interest to the UE for simultaneously for one or more respective MBS services of interest. For example, but not limited to, the sixth value can comprise <PTM + PTP>.

[0063] In another embodiment, with reference to Figure 8A method 800 for wireless communication includes sending, to a gNB central unit (gNB-CU), a load status of a next generation radio access network node distributed unit (gNB-DU) for a multicast broadcast service (MBS) service using a non-user equipment (non-UE) associated F1AP message. The method 800 can include a step 810 of sending, by the next generation radio access network node distributed unit (gNB-DU), multicast broadcast service (MBS) resource status information to the gNB central unit (gNB-CU) to inform the gNB-CU about a resource status in the gNB-DU for the MBS service. In an implementation, the gNB-DU can send a non-UE associated F1AP message to the gNB-CU, the non-UE associated F1AP message including a MBS load indication indicating the load status of the gNB-DU for the MBS service.

[0064] Figure 9 An example logical flow of a method 900 for sending, to a gNB central unit (gNB-CU) 904, a load status of a next generation radio access network node distributed unit (gNB-DU) 902 for a multicast broadcast service (MBS) service using a non-user equipment (non-UE) associated F1AP message is shown.

[0065] The method 900 can include a step 910 of sending, by the gNB-DU 902, a non-UE associated F1AP message to the gNB-CU 904. The non-UE associated F1AP message can include MBS resource status information to inform the gNB-CU about a resource status in the gNB-DU or a cell of the gNB-DU for the MBS service. In an implementation, the MBS resource status information includes a MBS load indication indicating whether the gNB-DU is overloaded for the MBS service. In another implementation, the MBS resource status information includes a ratio of resources occupied by the MBS service in the gNB-DU. In another implementation, the MBS resource status information includes a cell MBS load indication indicating whether each cell of the gNB-DU is overloaded for the MBS service. In another implementation, the MBS resource status information includes a ratio of radio resources occupied by the MBS service in each cell of the gNB-DU.

[0066] In one implementation, the method 900 can further include that, in response to the MBS load indication indicating that the gNB-DU or the cell is overloaded for the MBS service, the gNB-CU 904 applies an overload reduction action for the MBS service. The overload reduction action can be applied until the overload condition is resolved. When the overload condition is resolved and a non-overload condition occurs, the gNB-DU 902 can send a new MBS load indication to the gNB-CU 904 indicating the non-overload status. In this way, in response to the ongoing overload reduction action and the new MBS load indication indicating the non-overload status, the gNB-CU stops the ongoing overload reduction action for the MBS service. The detailed overload reduction strategy can be determined and implemented by the gNB-CU 904.

[0067] In another implementation, the method 900 can alternatively and optionally include a step 920 that the gNB-CU 904 sends a second non-UE-associated F1AP message to the gNB-DU 902. The second non-UE-associated F1AP message can include configuration information for MBS load indication, which includes an MBS load threshold. When the MBS load condition is higher than the MBS load threshold, the gNB-DU 902 determines the MBS load indication as overloaded; while when the MBS load condition is not higher than the MBS load threshold, the gNB-DU 902 determines the MBS load indication as non-overloaded. In one implementation, the step 920 can be performed before the step 910. In another implementation, the step 920 can be performed after the step 910.

[0068] In another embodiment, the MBS load indication can include at least one of the following information elements (IEs): message type, transaction ID, and / or gNB-DU load status for MBS, and / or a list of cell identities in the gNB-DU. For each cell identity, the MBS load indication further includes a cell load status for MBS. For example, but not limited to, the gNB-DU load status for MBS can indicate overload information in the gNB-DU for MBS, which has an enumerated value including overload and non-overload, or a value of at least one of overload and non-overload. In another embodiment, the gNB-DU load status for MBS can indicate a ratio of resources occupied by MBS services in the gNB-DU, which has a value ranging from 0 to 1 (including 0 and 1) (i.e., [0, 1]). For example, but not limited to, the IE indicating the cell load status for MBS can indicate overload information in the corresponding cell for MBS, which has an enumerated value including overload and non-overload, or a value of at least one of overload and non-overload. In another embodiment, the IE indicating the cell load status for MBS can indicate a ratio of resources occupied by MBS services in the corresponding cell, which has a value ranging from [0, 1]. In another embodiment, referring to Figure 10 The method 1000 for wireless communication includes transmitting, using an FlAP message, a usage status of at least one radio bearer (RB) for a multicast broadcast service (MBS) session from a next generation radio access network node distributed unit (gNB-DU) to a gNB centralized unit (gNB-CU). The method 1000 can include a step 1010 of transmitting, by the next generation radio access network node distributed unit (gNB-DU) to the gNB centralized unit (gNB-CU), multicast broadcast service (MBS) notification information to notify the gNB-CU that a quality of service (QoS) of an already established guaranteed bit rate (GBR) radio bearer (RB) associated with the MBS session can no longer be satisfied or can be satisfied again.

[0069] The purpose of the MBS notification procedure can be to enable the gNB-DU to notify the gNB-CU that a quality of service (QoS) of an already established guaranteed bit rate (GBR) radio bearer (RB) associated with the MBS session can no longer be satisfied or can be satisfied again. In one embodiment, the procedure can use MBS session associated signaling. In another embodiment, the procedure can use UE associated signaling. In another embodiment, the procedure can use non-UE associated signaling.

[0070] In one embodiment, the RBs include at least one of point-to-multipoint (PTM) radio bearers and optional data RBs (DRBs).

[0071] Figure 11 An example logic flow for a method 1100 for using F1AP messages to send usage status of at least one radio bearer (RB) for a MBS session from a next generation radio access network node-distributed unit (gNB-DU) 902 to a gNB-centralized unit (gNB-CU) 904 is shown.

[0072] The method 1100 can include a step 1110 of the gNB-DU 1102 sending a F1AP message to the gNB-CU 1104. The F1AP message can include MBS notification information, and the MBS notification information can indicate usage status of at least one RB for a MBS session. In one embodiment, the MBS notification information includes a list of GRB PTM transmission modes of the RBs, and optionally a list of GRB DRBs associated with a notification control for which the QoS can no longer be satisfied or for which the QoS is again satisfied by the gNB-DU.

[0073] In one embodiment, in response to receiving the MBS notification indication, the gNB-CU 1104 identifies a subset of at least one RB having a satisfied status. In another embodiment, in response to receiving the MBS notification indication, the gNB-CU 1104 identifies a subset of at least one RB having an unsatisfied status.

[0074] The gNB-CU 1104 identifies which QoS flows and MBS sessions are affected, and notifies the core network that the QoS or these QoS flows for the MBS session are no longer satisfied or are again satisfied.

[0075] In another embodiment, referring to Table 1, the MBS notification indication can include a PTM transmission mode of RBs. The MBS notification indication can include at least one information element (IE) of: a gNB-CU MBS FlAP identification (ID), a gNB-DU MBS FlAP identification, a MBS session identification, a MBS service identification, and a point-to-multipoint (PTM) RB (MRB) notification list. Each of the MRB notification list can include a point-to-multipoint (PTM) RB notification list, where each of the PTM RB notification list includes a cell identification, a MRB identification, and a MRB notification cause. The MRB notification list corresponds to a point-to-multipoint (PTM) RB list; and each of the MRB notification cause list can include: a value containing enumerated values of satisfied and not satisfied, or at least one of satisfied and not satisfied. For example, but not limited to, the MBS service identification can include a temporary mobile group identification (TMGI).

[0076] Table 1: MBS notification indication

[0077] ■IE / Group Name IE Type and Reference ■Message Type ■gNB-CU MBS F1AP ID ■gNB-DU MBS F1AP ID ■MBS Session ID ■MBS Service ID ■DRB Notification List ■>DRB Notification Item IE ■>>gNB-CU UE F1AP ID ■>>gNB-DU UE F1AP ID ■>>DRB ID ■>>Notification Reason Enumerated (satisfied, not satisfied,...) ■MRB Notification List ■>MRB Notification Item IE ■>>Cell ID ■>>PTM RB ID ■>>Notification Reason Enumerated (satisfied, not satisfied,...)

[0078] Optionally, referring to Table 1, the MBS notification indication can also include a PTP transmission mode of RBs. The MBS notification indication can also include a data RB (DRB) notification list. Each of the DRB notification list can include a gNB-CU user equipment (UE) FlAP identification, a gNB-DU UE FlAP identification, a DRB identification list, and a DRB notification cause list corresponding to the DRB identification list. The DRB notification list corresponds to a point-to-point (PTP) RB list; and each of the DRB notification cause list can include: a value containing enumerated values of satisfied and not satisfied, or at least one of satisfied and not satisfied,

[0079] Methods, apparatuses, and computer readable media for wireless communications are described. The disclosure addresses the problem of selecting radio bearer modes for multicast broadcast services (MBS). The methods, devices, and computer readable media described in the disclosure can improve the performance of wireless communications by selecting PTP or PTM transmission modes for one or more respective MBS services, thereby improving efficiency and overall performance. The methods, devices, and computer readable media described in the disclosure can improve the overall efficiency of a wireless communication system.

[0080] Throughout this specification, the use of the term "implementation" or "implementation of the present solution" does not necessarily refer to a specific embodiment, but can refer to a specific feature, structure, or property of an embodiment. Thus, use of the term "implementation" or "implementation of the present solution" can refer to a feature, structure, or property of an embodiment that can or can not be included in one or more other embodiments. In some cases, use of the term "implementation" or "implementation of the present solution" can refer to a feature, structure, or property that can or can not be included in one or more other embodiments.

[0081] Furthermore, the described features, advantages, and characteristics of the present solution can be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize, in light of the description herein, that the present solution can be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages can be recognized in certain embodiments that can not be present in all embodiments of the present solution.

Claims

1. A method for wireless communications, comprising: informing a radio access network (RAN) that a user equipment (UE) is receiving / is interested in receiving or is no longer receiving / is no longer interested in receiving a multicast broadcast service (MBS) service via a transmission mode by: sending, by the UE to the RAN, MBS interest information including a list of interested MBS services, wherein: the MBS interest information further includes a transmission mode interest indication, and the transmission mode interest indication includes a plurality of values, one of which is a value indicating that the UE is interested in using both a point-to-point (PTP) transmission mode and a point-to-multipoint (PTM) transmission mode. 2.The method of claim 1, wherein: for each item in the list of interested MBS services, the transmission mode interest indication indicates a transmission mode that the UE is interested in for receiving the corresponding MBS service. 3.The method of claim 1, wherein: the transmission mode interest indication indicates a transmission mode that the UE is interested in for receiving all interested MBS services. 4.The method of claim 1, wherein: each item in the list of interested MBS services includes at least one of: an MBS service identity, a set of quality of service (QoS) flow identities, an MBS session identity, an IP multicast address, an IP source address, or a temporary mobile group identity (TMGI). 5.The method of any one of claims 1-3, wherein: the plurality of values further includes at least one of: a first value indicating that the UE is interested in using a PTP transmission mode; a second value indicating that the UE is interested in using a PTM transmission mode; a third value indicating that the UE is interested in using either a PTP transmission mode or a PTM transmission mode, and the PTP transmission mode has a higher priority than the PTM transmission mode; a fourth value indicating that the UE is interested in using either a PTP transmission mode or a PTM transmission mode, and the PTM transmission mode has a higher priority than the PTP transmission mode; a fifth value indicating that the UE has no specific interest in which transmission mode to use. 6.The method of any one of claims 2-3, wherein: a trigger condition for sending the MBS interest information includes when a transmission mode interest changes. 7.A method for wireless communications, comprising: sending, by a core network (CN) to a radio access network (RAN), multicast broadcast service (MBS) session management information including at least one of: an MBS session identity, a list of MBS service identity information associated with the MBS session, a list of quality of service (QoS) flow identities associated with the MBS session, a list of user equipment (UE) identities joining the MBS session, wherein: the MBS session management information further includes a transmission mode interest indication, and the transmission mode interest indication includes a plurality of values, one of which is a value indicating that the UE is interested in using both a point-to-point (PTP) transmission mode and a point-to-multipoint (PTM) transmission mode. The transmission mode interest indication includes a plurality of values, one of the plurality of values being a value indicating that the UE is interested in using both a point-to-point (PTP) transmission mode and a point-to-multipoint (PTM) transmission mode.

8. The method of claim 7, wherein: The MBS session management information includes one of MBS session start information, MBS session update information, MBS session setup information, and MBS session modification information.

9. The method of claim 7, wherein: For each item in the UE identity list, the transmission mode interest indication indicates a transmission mode that the UE is interested in for receiving data of the MBS session.

10. The method of claim 7, wherein: For each item in the UE identity list for each item in the MBS service identity information list, the transmission mode interest indication indicates a transmission mode that the UE is interested in for receiving data of the corresponding MBS service.

11. The method of claim 7, further comprising: sending, by the UE, MBS service request information to a core network (CN), the MBS service request information including MBS service identity information corresponding to a requested MBS service, and the transmission mode interest indication indicating a transmission mode that the UE is interested in for receiving the MBS service.

12. The method of claim 7, wherein: The MBS service identity information includes at least one of: an MBS service identity, an MBS session identity, and a set of quality of service (QoS) flow identities, an MBS session identity, an IP multicast address, an IP source address, or a temporary mobile group identity (TMGI).

13. The method of any one of claims 7-10, wherein: The plurality of values further includes at least one of: a first value indicating that the UE is interested in using a PTP transmission mode; a second value indicating that the UE is interested in using a PTM transmission mode; a third value indicating that the UE is interested in using either a PTP transmission mode or a PTM transmission mode, and the PTP transmission mode has a higher priority than the PTM transmission mode; a fourth value indicating that the UE is interested in using either a PTP transmission mode or a PTM transmission mode, and the PTM transmission mode has a higher priority than the PTP transmission mode; a fifth value indicating that the UE has no interest in using either transmission mode.

14. A method for wireless communication, comprising: sending, by a next generation radio access network node distributed unit (gNB-DU), multicast broadcast service (MBS) resource status information to a gNB centralized unit (gNB-CU) to inform the gNB-CU about resource status in the gNB-DU for MBS services; and receiving, by the gNB-DU, configuration information from the gNB-CU, the configuration information including MBS load thresholds.

15. The method of claim 14, wherein: The MBS resource status information includes a MBS load indication indicating whether the gNB-DU is overloaded for MBS services.

16. The method of claim 14, wherein: The MBS resource status information includes a ratio of resources occupied by MBS services in the gNB-DU.

17. The method of claim 14, wherein: The MBS resource status information includes a cell MBS load indication indicating whether each cell of the gNB-DU is overloaded for MBS services.

18. The method of claim 14, wherein The MBS resource status information includes a ratio of radio resources occupied by MBS services in each cell of the gNB-DU.

19. The method of claim 15, wherein: In response to the MBS load indication indicating that the gNB-DU is overloaded for MBS services, the gNB-CU applies an overload reduction action for the MBS services.

20. The method of claim 19, wherein: if the overload condition has stopped, the gNB-DU sends a new MBS load indication to the gNB-CU; and in response to the ongoing overload reduction action and the new MBS load indication indicating a non-overload status, the gNB-CU stops the ongoing overload reduction action for the MBS services.

21. The method of claim 15, further comprising: in response to a MBS load condition being higher than the MBS load threshold, determining, by the gNB-DU, the MBS load indication as overloaded; and in response to a MBS load condition not being higher than the MBS load threshold, determining, by the gNB-DU, the MBS load indication as not overloaded.

22. The method of claim 15, wherein: The MBS load indication has a value of at least one of overloaded or not overloaded.

23. A method for wireless communication, comprising: sending, by a next generation radio access network node distributed unit (gNB-DU) to a gNB centralized unit (gNB-CU), multicast broadcast service (MBS) notification information to notify the gNB-CU that a quality of service (QoS) of an already established guaranteed bit rate (GBR) radio bearer (RB) associated with a MBS session is no longer satisfied or can be satisfied again, wherein: the MBS notification information includes a list of GBR PTM RBs and includes a list of GBR DRBs associated with a notification control for which the QoS is no longer satisfied or for which the QoS is satisfied again by the gNB-DU; and in response to receiving the MBS notification information, the gNB-CU identifies the QoS flows and MBS session that are affected and notifies a core network that the QoS or the QoS flows for the MBS session is no longer satisfied or satisfied again.

24. The method of claim 23, wherein: The RBs include at least one of point-to-multipoint (PTM) radio bearers and data RBs (DRBs).

25. The method of claim 23, wherein: the MBS notification information uses F1AP signaling associated with the MBS session, or UE-associated F1AP signaling, or non-UE-associated F1AP signaling.

26. The method of claim 23, wherein: the MBS notification information includes at least one of: a gNB-CU MBS F1AP identity, a gNB-DU MBS F1AP identity, an MBS session identity, an MBS service identity, a data RB (DRB) notification list, wherein each of the DRB notification list includes a gNB-CU user equipment (UE) F1AP identity, a gNB-DU UE F1AP identity, a DRB identity list, and a DRB notification cause, and a point-to-multipoint (PTM) RB notification list, wherein each of the PTM RB notification list includes a cell identity, an MRB identity, and an MRB notification cause.

27. The method of claim 26, wherein: the DRB notification list corresponds to a point-to-point (PTP) RB list; and the DRB notification cause includes a value of at least one of fulfilled or not fulfilled.

28. The method of claim 26, wherein: the MRB notification list corresponds to a point-to-multipoint (PTM) RB list; and the MRB notification cause includes a value of at least one of fulfilled or not fulfilled.

29. A wireless communication apparatus comprising a processor and a memory, wherein the processor is configured to read code from the memory and implement a method according to any one of claims 1 to 28.

30. A computer program product comprising a computer readable program medium code stored thereon, which code, when executed by a processor, causes the processor to implement a method according to any one of claims 1 to 28.

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