Wireless communication method and apparatus for multicast / broadcast service

Abstract

The invention discloses a wireless communication method and a wireless communication device for a multicast / broadcast service (MBS), and the wireless communication method and the wireless communication device are used for the MBS. The method is performed by a user equipment (UE), including changing UE preferences from connected mode reception to inactive mode reception, or from inactive mode reception to connected mode reception, and notifying a base station of a UE preference change. The method also includes performing a registration update procedure when the UE preference changes.

Description

Technical Field

[0001] The present application relates to the field of wireless communication systems, and more specifically, to a wireless communication method and apparatus for multicast / broadcast service (MBS), for example, particularly to an MBS system. Background Art

[0002] In 3rd Generation Partnership Project (3GPP) cellular networks, broadcast and multicast services are delivered via a transport service called Multimedia Broadcast / Multicast Service (MBMS). A Broadcast Multicast Service Center (BM-SC) server distributes media content to a group of subscribed users. When user equipment (UE) moves outside of network coverage, it may be unable to use MBMS because it can no longer establish uplink and downlink connections with the BM-SC server. MBMS is a point-to-multipoint (PTM) interface specification designed to efficiently provide broadcast and multicast services in 3GPP cellular networks. Examples of MBMS interface specifications include those described in the Universal Mobile Telecommunications System (UMTS) and Long Term Evolution (LTE) communication specifications. These specifications define transmissions over a single frequency network configuration for broadcasts across multiple cells. Typical applications of MBMS include mobile television, news, radio stations, file transfers, and emergency alerts. When MBMS broadcasts a service, all cells within a multimedia broadcast / multicast service single frequency network (MBSFN) area transmit the same MBMS service.

[0003] Users can access these services and obtain MBMS content through wireless communication devices (such as cell phones, tablets, laptops, and other devices with wireless transceivers). These devices receive services by communicating with base stations in the communication system. Base stations provide wireless services to wireless communication devices (sometimes referred to as mobile devices or UEs) within the cell range. Users can access at least some multimedia services through UEs using point-to-point (PTP) connections or PTM transmission. In 3GPP systems, PTP services can be provided through unicast technology, while PTM transmission can be provided through MBMS communication, which can be transmitted via MBSFN or single cell point to multipoint (SC-PTM) communication. In systems compliant with certain revisions of the 3GPP LTE communication specifications, MBMS can be provided through enhanced MBMS (eMBMS). Therefore, in LTE systems, MBMS services can be provided through unicast services, MBSFN, or SC-PTM.

[0004] To enable resource-efficient multicast / broadcast service delivery, 3GPP developed NR broadcast / multicast under a work item (WID) in Rel-17, aiming to support general MBS services on the 5GS. Identified applicable scenarios include public safety and mission-critical communications, vehicle-to-everything (V2X) applications, IPTV, live video, wireless software delivery, and Internet of Things (IoT) applications. Rel-17 MBS defines two transmission modes: Mode 1 (for multicast only) meets higher QoS service requirements, while Mode 2 (for broadcast only) focuses on lower QoS services. Given that Rel-17 MBS already provides the basic functionality to support MBS services, the primary goal of Rel-18 should be to optimize MBS deployment, for example, by improving resource efficiency and capacity based on Rel-17 MBS.

[0005] In Rel-17, the Radio Access Network (RAN) only supports multicast for UEs in the RRC_CONNECTED state. This may not fully meet the needs of mission-critical services, especially for cells with a large number of UEs (see TR 23.774). In addition, always keeping the UE in the RRC_CONNECTED state is not in line with power consumption optimization. Therefore, it is very important to support multicast for UEs in the RRC_INACTIVE state.

[0006] Therefore, there is an urgent need for a wireless communication method and apparatus for multicast / broadcast service (MBS). Summary of the Invention

[0007] The purpose of this application is to provide a wireless communication method and apparatus for multicast / broadcast service (MBS).

[0008] In a first aspect of the present application, a wireless communication method for multicast / broadcast service (MBS) is performed by user equipment (UE), including changing the UE preference from connected mode reception to inactive mode reception, or from the inactive mode reception to the connected mode reception; and notifying a base station of the UE preference change.

[0009] In a second aspect of the present application, a user equipment (UE) includes a memory, a transceiver, and a processor coupled to the memory and the transceiver. The processor is configured to execute the above method.

[0010] In a third aspect of the present application, a non-transitory machine-readable storage medium stores instructions, which, when executed by a computer, cause the computer to perform the above method.

[0011] In a fourth aspect of the present application, a chip includes a processor configured to call and run a computer program stored in a memory, so that a device on which the chip is installed executes the above method.

[0012] In a fifth aspect of the present application, a computer-readable storage medium stores a computer program, which enables a computer to execute the above method.

[0013] In a sixth aspect of the present application, a computer program product includes a computer program, which enables a computer to execute the above method.

[0014] In a seventh aspect of the present application, a computer program causes a computer to execute the above method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present application or related technologies, the following briefly introduces the drawings to be described in the embodiments. Obviously, the drawings are only some embodiments of the present application, and ordinary technicians in this field can obtain other drawings based on these drawings without paying any price.

[0016] Figure 1 This is a block diagram of one or more user equipment (UE) communicating with a base station (e.g., gNB) in a communication network system according to an embodiment of the present application.

[0017] Figure 2 4 is a flowchart of a wireless communication method for MBS performed by a UE according to an embodiment of the present application.

[0018] Figure 3 4 is a flowchart of a wireless communication method for MBS according to an embodiment of the present application.

[0019] Figure 4 4 is a flowchart of a wireless communication method for MBS according to an embodiment of the present application.

[0020] Figure 5 4 is a flowchart of a wireless communication method for MBS according to an embodiment of the present application.

[0021] Figure 6 4 is a flowchart of a wireless communication method for MBS according to an embodiment of the present application.

[0022] Figure 7 4 is a flowchart of a wireless communication method for MBS according to an embodiment of the present application.

[0023] Figure 8 4 is a flowchart of a wireless communication method for MBS according to an embodiment of the present application.

[0024] Figure 9 4 is a flowchart of a wireless communication method for MBS according to an embodiment of the present application.

[0025] Figure 10 This is a system block diagram for wireless communication according to an embodiment of the present application. DETAILED DESCRIPTION

[0026] The following describes the technical content, structural features, objectives and effects of the present application in detail with reference to the accompanying drawings. Specifically, the terms in the embodiments of the present application are only used to describe the purpose of specific embodiments and are not intended to limit the present application.

[0027] At the RANP#94 meeting, the following Release 18 Work Instructions (WIDs) were approved. This work item aims to further enhance NR multicast / broadcast capabilities based on Rel-17 MBS. The objectives of Rel-18 include: 1. Specification of support for multicast reception by UEs in RRC_INACTIVE state [RAN2, RAN3]. Specification of PTM configuration for UEs receiving multicast in RRC_INACTIVE state [RAN2]. Study of the impact of UEs receiving multicast in RRC_INACTIVE state on mobility and state transitions [RAN2, RAN3]. 2. Specification of Uu signaling enhancements to enable UEs to share processing capabilities for MBS broadcast and unicast reception, including: UE capability and related assistance information reporting to indicate whether unicast reception and MBS broadcast reception in RRC_CONNECTED state are from the same operator or different operators [RAN2]. 3. Study and, if necessary, specify optimization of resource efficiency for MBS reception in RAN sharing scenarios [RAN3].

[0028] To provide MBS services to more UEs within a cell, the RAN can enable UEs in an MBS multicast session to receive MBS session data in the RRC_INACTIVE state. This means that within the same cell and the same MBS multicast session, some UEs may be in the RRC_INACTIVE state while others may be in the RRC_CONNECTED state. Assume that the network (NW) can select which UEs receive data in the RRC_INACTIVE state and which in the RRC_CONNECTED state, and can switch UEs between the two states during multicast service reception, as agreed upon by the RAN. Assume that the network can select which UEs receive data in the RRC_INACTIVE state and which in the RRC_CONNECTED state, and can switch UEs between the two states during multicast service reception. RAN2 has also determined that the gNB will determine whether a multicast session can be received by a UE in the RRC_INACTIVE state. The information the gNB needs to obtain to make this determination (discussed in SA2) remains to be further clarified. As mentioned above, the UE's RRC state when receiving multicast services is affected by two factors: whether a multicast session can be received by a UE in the RRC_INACTIVE state. The network selects which UEs are in the RRC_INACTIVE state and which are in the RRC_CONNECTED state. In this application, we use the term "transmission mode" to describe the RRC state of a UE when receiving multicast services, encompassing both of these factors. Therefore, the transmission mode is determined by the gNB. However, the gNB may require certain assistance information to make this decision, which may come from the 5GC, the UE, or both. Several approaches have been discussed regarding how the UE can provide assistance information to the gNB to help it determine the transmission mode. In this application, we focus on one approach, in which the UE provides assistance information to the gNB through a registration procedure. The questions we address are: What factors cause a change in the UE's initial preference (one of the assistance information provided by the UE to the gNB)? And what procedures should be followed when a UE's preference changes?

[0029] In some embodiments of this application, we focus on a solution where the UE provides assistance information to the gNB through a registration procedure. The question we address is: What factors cause a change in the UE's initial preferences (one piece of assistance information provided by the UE to the gNB)? What procedures should be followed when the UE preferences change?

[0030] Figure 1The present invention illustrates one or more user equipment (UE) 10 and a base station (e.g., gNB) 20 for communication in a communication network system 40 according to one embodiment of the present application. The communication network system 40 includes one or more UEs 10 and base stations 20. The one or more UEs 10 may include a memory 12, a transceiver 13, and a processor 11 coupled to the memory 12 and transceiver 13. The base station 20 may include a memory 22, a transceiver 23, and a processor 21 coupled to the memory 22 and transceiver 23. The processor 11 or 21 may be configured to perform the functions, processes, and / or methods described herein. The various layers of the radio interface protocol may be implemented in the processor 11 or 21. The memory 12 or 22 is operatively coupled to the processor 11 or 21 for storing various information to support the operation of the processor 11 or 21. The transceiver 13 or 23 is operatively coupled to the processor 11 or 21 for transmitting and / or receiving wireless signals.

[0031] The processor 11 or 21 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. The memory 12 or 22 may include a read-only memory (ROM), a random access memory (RAM), flash memory, a memory card, a storage medium, and / or other storage devices. The transceiver 13 or 23 may include a baseband circuit for processing radio frequency signals. When the embodiment is implemented in software, the technology described herein may use modules (such as procedures, functions, etc.) to perform the functions. These modules may be stored in the memory 12 or 22 and executed by the processor 11 or 21. The memory 12 or 22 may be integrated inside the processor 11 or 21 or located outside the processor 11 or 21 and coupled thereto through various communication methods (for example, in accordance with industry technical standards).

[0032] In some embodiments, the processor 11 is configured to change the UE preference from connected mode reception to inactive mode reception or from inactive mode reception to connected mode reception, and the transceiver 13 is configured to notify the base station 20 of the UE preference change.

[0033] Figure 2This is a flow chart of a wireless communication method 200 for a multicast / broadcast service (MBS) performed by a user equipment (UE) according to one embodiment of the present application. In some embodiments, the MBS wireless communication method 200 performed by the UE includes: Step 202: Changing the UE preference from connected mode reception to inactive mode reception, or vice versa. Step 204: Notifying a base station of the UE preference change.

[0034] In some embodiments, before the UE preference is changed, the UE receives multicast MBS data in a connected state or an inactive state. In some embodiments, the UE preference change may occur due to a change in power level. In some embodiments, the UE preference change is one of the auxiliary information provided by the UE to the base station. In some embodiments, the method further includes receiving a radio resource control (RRC) release message from the base station after the UE preference change, wherein the UE switches from the connected state to the inactive state based on the RRC release message. In some embodiments, the UE continues to receive multicast MBS data in the inactive state after the preference change.

[0035] In some embodiments, the method further includes receiving information from a base station after the UE preference changes, wherein the UE switches from an inactive state to a connected state based on the information. In some embodiments, the UE continues to receive multicast MBS data in the connected state after the preference changes. In some embodiments, the method further includes performing a registration update procedure when the UE preference changes.

[0036] Specifically, in some examples, the method also includes receiving a radio resource control (RRC) release message from the base station after changing the UE preference from connected mode reception to inactive mode reception, wherein the UE switches from the connected state to the inactive state based on the RRC release message.

[0037] In some examples, after changing the UE preference from connected mode reception to inactive mode reception, the UE continues to receive multicast MBS data in the inactive state. In some examples, after changing the UE preference from inactive mode reception to connected mode reception, the UE continues to receive multicast MBS data in the inactive state even after the preference change. Specifically, in some examples, the method further includes receiving information from a base station after changing the UE preference from inactive mode reception to connected mode reception, wherein the UE switches from the inactive state to the connected state based on the information. In some examples, after changing the UE preference from connected mode reception to inactive mode reception, the UE continues to receive multicast MBS data in the connected state. In some examples, after changing the UE preference from connected mode reception to inactive mode reception, the UE continues to receive multicast MBS data in the connected state even after the preference change.

[0038] In some embodiments, the registration update procedure includes a periodic registration update procedure or a mobility registration update procedure. In some embodiments, in the periodic registration update procedure, the UE sends a registration request and UE preference change information to the base station and receives a registration accept message from the access and mobility management function (AMF). In some embodiments, the condition for triggering the periodic registration update procedure is the expiration of a related timer.

[0039] In some embodiments, during the mobility registration update procedure, the UE sends a registration request and UE preference change information to the base station and receives a registration accept message from the AMF. In some embodiments, the UE preference change is one of the triggering conditions for triggering the registration update procedure.

[0040] Figures 3 to 9 This section describes an example of a UE preference change during a transmission mode determination process, according to embodiments of the present application. In some embodiments of the present application, the process primarily includes two parts: Part 1 describes factors that may trigger a UE preference change; Part 2 describes the process to be executed when a UE preference change occurs.

[0041] UE Preference Changes:

[0042] One factor that may trigger a change in UE preference is power variation. When the UE has sufficient battery power and desires high reliability, it prefers to remain in the connected state to receive multicast services. However, if the UE's battery power is too depleted to support connected reception, the UE may change its preference and notify the gNB accordingly.

[0043] When a UE initially receives a multicast service in the connected state and subsequently notifies the gNB of a preference change, the gNB may decide to switch the UE to the inactive state or to keep it in the connected state. Figure 3 (gNB decides to switch to inactive state) and Figure 4 (gNB decides to remain connected).

[0044] When a UE initially receives a multicast service in the Inactive state and subsequently notifies the gNB of a preference change, the gNB may decide to switch the UE to the Connected state or to keep it in the Inactive state. Figure 5 (gNB decides to switch to connected state) and Figure 6 (gNB decides to remain in inactive state).

[0045] The process can be described as follows:

[0046] (1) The UE receives multicast MBS data in the connected state.

[0047] (2) UE preferences change due to power level changes (e.g., low battery).

[0048] (3) The UE notifies the gNB of its preference change (UE preference change is one of the auxiliary information provided by the UE to the gNB).

[0049] (4) Based on the assistance information, the gNB decides to switch the UE in the multicast MBS session to the inactive state.

[0050] (5) The gNB releases the RRC connection by sending an RRC Release message and moves the UE to the Inactive state.

[0051] (6) The UE continues to receive multicast MBS data in the inactive state.

[0052] The process can be described as follows:

[0053] (1) The UE receives multicast MBS data in an inactive state.

[0054] (2) The UE preference changes due to a change in power level (e.g., battery is restored to full capacity).

[0055] (3) The UE notifies the gNB of its preference change (UE preference change is one of the auxiliary information provided by the UE to the gNB).

[0056] (4) Based on the auxiliary information, the gNB decides to switch the UE in the multicast MBS session to the connected state.

[0057] (5) The gNB notifies the relevant UE to switch to the connected state.

[0058] (6) The UE switches to the connected state and continues to receive multicast MBS data in the connected state.

[0059] Based on the instructions from above:

[0060] Another preference change method is based on upper layer indication, which the UE can use to inform the network that it wants to receive multicast services in inactive mode.

[0061] Figures 3 to 6 This section describes how the UE notifies the gNB of its preference change and how the gNB notifies the UE to switch to the connected state when the UE is initially in the inactive state.

[0062] In some examples, we assume that the UE registration procedure is used to transmit assistance information from the UE to the gNB. The registration type indicates the type of registration performed by the UE, including the following: Initial Registration: Performed when the UE is in the RM-DEREGISTERED state. Mobility Registration Update: When the UE is in the RM-REGISTERED state and initiates a registration procedure due to mobility, updating capabilities or protocol parameters, or requesting a change to its allowed set of network slices. Periodic Registration Update: When the UE is in the RM-REGISTERED state and initiates a registration procedure due to the expiration of the periodic registration update timer, the registration procedure is initiated. Emergency Registration: Performed when the UE is in the limited service state. Disaster Roaming Initial Registration. Disaster Roaming Mobility Registration Update.

[0063] When UE preferences change, the UE can perform a registration update procedure to notify the gNB of the UE preference change. Two solutions are possible: First, the UE performs a traditional registration update procedure, including the mobility registration update procedure and the periodic registration update procedure, and includes information about the UE preference change in the information sent to the gNB, as shown in the previous embodiment. Second, the UE preference change itself serves as one of the triggering conditions for the registration update procedure.

[0064] The UE performs the periodic registration update process:

[0065] Figure 7 In some embodiments, the steps of performing a periodic registration update procedure by the UE are as follows:

[0066] (1) The UE sends a registration request to the gNB along with information related to the UE preference change, such as an identifier indicating the UE preference change.

[0067] (2) The gNB performs AMF selection.

[0068] (3) The gNB sends a registration request to the AMF.

[0069] (4)AMF sends a Registration Accept to the UE.

[0070] Conditions for triggering the periodic registration update process: expiration of the relevant timer.

[0071] The UE performs the mobility registration update procedure:

[0072] Figure 8 In some embodiments, the steps of performing the mobility registration update procedure by the UE are as follows:

[0073] (1) The UE sends a registration request to the gNB along with information related to the UE preference change, such as an identifier indicating the UE preference change.

[0074] (2) The gNB performs AMF selection.

[0075] (3) The gNB sends a registration request to the new AMF.

[0076] (4) The new AMF sends a UE context transfer request to obtain the UE context.

[0077] (5) The old AMF transfers the UE context to the new AMF and responds to the UE context transfer request.

[0078] (6) The new AMF sends a registration completion message to the old AMF.

[0079] (7) The new AMF sends a registration accept message to the UE.

[0080] In some examples, UE preference change is one of the triggering conditions for triggering the registration update procedure.

[0081] Figure 9 In some embodiments, the UE performs the following steps:

[0082] (1) The UE receives multicast MBS data in the inactive / connected state.

[0083] (2) UE preferences change due to factors such as power level changes.

[0084] (3) UE triggers the registration update process.

[0085] In summary, in some embodiments of this application, we focus on a solution where the UE provides assistance information to the gNB through a registration procedure. The question we address is: What factors cause a change in the UE's initial preferences (one piece of assistance information provided by the UE to the gNB)? What procedures should be followed when the UE preferences change? This requirement is new in Release 18 MBS and did not exist previously.

[0086] Figure 10 7 is a block diagram of an exemplary wireless communication system 700 according to an embodiment of the present application. The embodiments described herein may be implemented in a system using any appropriately configured hardware and / or software. Figure 10 A system 700 is shown, which includes a radio frequency (RF) circuit 710, a baseband circuit 720, an application circuit 730, a memory / storage device 740, a display 750, a camera 760, a sensor 770, and an input / output (I / O) interface 780, which are coupled to each other at least as shown. The application circuit 730 may include circuits, such as but not limited to one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors, such as a graphics processor, an application processor. The processor may be coupled to the memory / storage device and configured to execute instructions stored in the memory / storage device to enable various applications and / or operating systems to run on the system.

[0087] While the present disclosure has been described in connection with what is considered to be the most practical and preferred embodiment, it is to be understood that the disclosure is not limited to the disclosed embodiment, but is intended to cover various arrangements that may be made without departing from the scope of the broadest interpretation of the appended claims.

Claims

1. A wireless communication method for a multicast / broadcast service MBS, performed by a user equipment UE, characterized in that: include: Changing the UE preference from connected mode reception to inactive mode reception, or from the inactive mode reception to the connected mode reception; as well as Notify the base station of the UE preference change.

2. The wireless communication method according to claim 1, characterized in that: Before the UE preference is changed, the UE receives multicast MBS data in a connected state or an inactive state.

3. The wireless communication method according to claim 1 or 2, characterized in that: The UE preference change is caused by a change in power level.

4. The wireless communication method according to any one of claims 1 to 3, characterized in that: The UE preference change is one of the auxiliary information provided by the UE to the base station.

5. The wireless communication method according to any one of claims 2 to 4, characterized in that: The method also includes receiving a radio resource control (RRC) release message from the base station after the UE preference is changed, wherein the UE switches from a connected state to an inactive state based on the RRC release message.

6. The wireless communication method according to claim 5, characterized in that: The step further includes receiving the RRC release message from the base station after changing the UE preference from the connected mode reception to the inactive mode reception, wherein the UE switches from the connected state to the inactive state based on the RRC release message.

7. The wireless communication method according to any one of claims 2 to 6, characterized in that: The UE continues to receive the multicast MBS data in the inactive state after the UE preference is changed.

8. The wireless communication method according to claim 7, characterized in that: After changing the UE preference from the connected mode reception to the inactive mode reception, the UE continues to receive the multicast MBS data in the inactive state.

9. The wireless communication method according to any one of claims 2 to 8, characterized in that: After changing the UE preference from the inactive mode reception to the connected mode reception, the UE continues to receive the multicast MBS data in the inactive state after the UE preference is changed.

10. The wireless communication method according to any one of claims 2 to 9, characterized in that: The further comprises receiving information from the base station after the UE preference is changed, wherein the UE switches from the inactive state to the connected state based on the information.

11. The wireless communication method according to claim 10, characterized in that: Receiving the information from the base station is subsequent to changing the UE preference from the inactive mode reception to the connected mode reception, wherein the UE switches from the inactive state to the connected state based on the information.

12. The wireless communication method according to any one of claims 2 to 11, characterized in that: The UE continues to receive the multicast MBS data in the connected state after the UE preference is changed.

13. The wireless communication method according to claim 12, characterized in that: After changing the UE preference from the connected mode reception to the inactive mode reception, the UE continues to receive the multicast MBS data in the connected state.

14. The wireless communication method according to any one of claims 1 to 13, characterized in that: Also included is performing a registration update procedure when the UE preference changes.

15. The wireless communication method according to claim 14, characterized in that: The registration update process includes a periodic registration update process or a mobility registration update process.

16. The wireless communication method according to claim 15, characterized in that: In the periodic registration update process, the UE sends a registration request and the UE preference change to the base station, and receives a registration accept message from the access and mobility management function AMF.

17. The wireless communication method according to claim 16, characterized in that: The condition for triggering the periodic registration update process is the expiration of a related timer.

18. The wireless communication method according to claim 15, characterized in that: In the mobility registration update process, the UE sends a registration request and the UE preference change to the base station, and receives a registration accept message from the AMF.

19. The wireless communication method according to any one of claims 14 to 18, characterized in that: The UE preference change is one of the triggering conditions for triggering the registration update process.

20. A user equipment, characterized in that: include: Memory; Transceiver; as well as a processor connected to the memory and the transceiver; The processor is configured to execute the method according to any one of claims 1 to 19.

21. A non-transitory machine-readable storage medium, characterized in that Instructions are stored which, when executed by a computer, cause the computer to perform the method of any one of claims 1 to 19.

22. A chip, characterized in that: include: The processor is configured to call and run the computer program stored in the memory so that the device on which the chip is installed executes the method according to any one of claims 1 to 19.

23. A computer-readable storage medium, characterized in that: A computer program is stored, the computer program causing a computer to execute the method according to any one of claims 1 to 19.

24. A computer program product, characterized in that It comprises a computer program causing a computer to execute the method according to any one of claims 1 to 19.

25. A computer program, characterized in that The computer program causes a computer to execute the method according to any one of claims 1 to 19.

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