CN-122029924-A - Communication method

Abstract

A communication method performed by a user equipment in a mobile communication system providing a multicast/broadcast service (MBS) includes receiving a Radio Resource Control (RRC) release message from a network node, the RRC release message causing the user equipment to transition to an RRC inactive state, wherein the RRC release message includes configuration information for receiving a multicast inactive Multicast Radio Bearer (MRB) of a multicast session in the RRC inactive state, confirming whether the RRC release message includes status information regarding whether the multicast session has been activated, and starting a multicast reception procedure using the multicast inactive MRB based on the configuration information when the RRC release message does not include the status information.

Inventors

• FUJISHIRO MASATO
• ZHANG XIANGYI

Assignees

• 京瓷株式会社

Dates

Publication Date

20260512

Application Date

20240801

Priority Date

20230802

Claims (9)

1. 1. A communication method performed by a user equipment in a mobile communication system providing a multicast/broadcast service MBS, the communication method comprising: receiving a radio resource control, RRC, release message from a network node, the RRC release message comprising PTM configuration information for receiving a multicast session in an RRC inactive state, the RRC release message causing the user equipment to transition to the RRC inactive state; confirming whether the RRC release message includes predetermined information indicating suspension of initiation of a multicast reception procedure for the multicast session, and The multicast receiving procedure is started based on the PTM configuration information when the RRC release message does not include the predetermined information.
2. 2. The communication method of claim 1, further comprising suspending initiation of the multicast reception procedure when the RRC release message includes the predetermined information.
3. 3. The communication method of claim 1, wherein the predetermined information is associated with a discontinuous reception, DRX, configuration to be applied to receive the multicast session.
4. 4. A communication method performed by a user equipment in a mobile communication system providing a multicast/broadcast service MBS, the communication method comprising: In a radio resource control, RRC, connected state, receiving a multicast session using a multicast-multicast radio bearer, MRB; receiving an RRC release message from a network node, the RRC release message including configuration information for receiving a multicast inactive MRB of a multicast session in an RRC inactive state, the RRC release message causing the user equipment to transition to the RRC inactive state; Confirming whether multicast inactive MRB corresponding to the multicast MRB is configured, and When a multicast inactive MRB corresponding to the multicast MRB is configured, a multicast reception procedure using the multicast inactive MRB is started.
5. 5. The communication method of claim 4, wherein the multicast inactive MRB corresponding to the multicast MRB is a multicast inactive MRB having a common MBS session ID with the multicast MRB or a multicast inactive MRB having a common MRB ID with the multicast MRB.
6. 6. The communication method according to claim 4 or 5, further comprising suspending starting the multicast reception procedure when a multicast inactive MRB that does not correspond to the multicast MRB is configured.
7. 7. A communication method performed by a user equipment in a mobile communication system providing a multicast/broadcast service MBS, the communication method comprising: Receiving a radio resource control, RRC, release message from a network node, the RRC release message comprising configuration information for receiving a multicast inactive multicast radio bearer, MRB, of a multicast session in an RRC inactive state, the RRC release message causing the user equipment to transition to the RRC inactive state; Attempting to receive the multicast session using the multicast inactive MRB based on pre-stored upper layer information, and When the reception of the multicast session is successful as a result of the attempt, continuing the multicast reception procedure using the multicast inactive MRB.
8. 8. The communication method according to claim 7, further comprising: the multicast reception process is stopped when receiving the multicast session is unsuccessful as a result of the attempt.
9. 9. The communication method according to claim 7 or 8, wherein, The user equipment performs the attempt within a specific time period while the attempt is made, and The specific time period is configured in the user equipment from the network node.

Description

Communication method Technical Field The present disclosure relates to a communication method used in a mobile communication system. Background The third generation partnership project (3 GPP) defines a technical specification for a New Radio (NR) as a fifth generation (5G) radio access technology. NR has characteristics such as high speed, large capacity, high reliability, and low latency, compared to Long Term Evolution (LTE), which is a fourth generation (4G) radio access technology. 3GPP has defined a technical specification for multicast/broadcast services (MBS) of 5G/NR. In 3GPP release 17, MBS multicast reception (i.e., multicast reception) can only support user equipment in a Radio Resource Control (RRC) connected state (for example, see non-patent document 1). On the other hand, in 3GPP release 18, the technical specification is planned to be extended so that the user equipment in the RRC inactive state can perform multicast reception. List of references Non-patent literature Non-patent document 1:3GPP technical Specification TS 38.300 V17.5.0 Disclosure of Invention The communication method according to the first aspect is a method performed by a user equipment in a mobile communication system for providing a multicast/broadcast service (MBS). The communication method includes receiving a Radio Resource Control (RRC) release message from a network node, the RRC release message including PTM configuration information for receiving a multicast session in an RRC inactive state, the RRC release message causing a user equipment to transition to the RRC inactive state, confirming whether the RRC release message includes predetermined information indicating suspension of a multicast reception procedure for the multicast session, and starting the multicast reception procedure based on the PTM configuration information when the RRC release message does not include the predetermined information. The communication method according to the second aspect is a communication method performed by a user equipment in a mobile communication system providing a multicast/broadcast service (MBS). The communication method includes receiving a multicast session using a Multicast Radio Bearer (MRB) in a Radio Resource Control (RRC) connected state, receiving an RRC release message from a network node, the RRC release message including configuration information for receiving a multicast inactive MRB of the multicast session in an RRC inactive state, the RRC release message causing a user equipment to transition to the RRC inactive state, confirming whether a multicast inactive MRB corresponding to the multicast MRB is configured, and starting a multicast reception procedure using the multicast inactive MRB when the multicast inactive MRB corresponding to the multicast MRB is configured. The communication method according to the third aspect is a communication method performed by a user equipment in a mobile communication system providing a multicast/broadcast service (MBS). The communication method includes receiving a Radio Resource Control (RRC) release message from a network node, the RRC release message including configuration information of a multicast non-active Multicast Radio Bearer (MRB) for receiving a multicast session in an RRC inactive state, the RRC release message causing a user equipment to transition to the RRC inactive state, attempting to receive the multicast session using the multicast non-active MRB based on pre-stored upper layer information, and continuing a multicast reception procedure using the multicast non-active MRB when the multicast session is received successfully as a result of the attempt. Drawings Fig. 1 is a diagram showing a configuration example of a mobile communication system according to an embodiment. Fig. 2 is a diagram showing a configuration example of a UE (user equipment) according to an embodiment. Fig. 3 is a diagram showing a configuration example of a gNB (network node) according to an embodiment. Fig. 4 is a configuration diagram showing a protocol stack of a radio interface of a user plane processing data. Fig. 5 is a configuration diagram showing a protocol stack of a radio interface of a control plane that handles signaling (control signals). Fig. 6 is an exemplary diagram illustrating an operation of the mobile communication system in a first operation mode according to an embodiment. Fig. 7 is an exemplary diagram illustrating an operation of the mobile communication system in the second operation mode according to the embodiment. Fig. 8 is an exemplary diagram illustrating an operation of the mobile communication system in a third operation mode according to an embodiment. Fig. 9 is a diagram illustrating an initial configuration procedure for connecting a UE. Detailed Description A mobile communication system according to an embodiment is described with reference to the accompanying drawings. In the description of the drawings, the same or similar parts are denoted