# US 12,764,616 B2 · Transmission switching method, terminal, and network-side device

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- Number: US 12,764,616 B2
- Document ID: US12764616B2
- Status: Granted
- Kind: B2
- Application number: 18/477,088
- Filed: 2023-09-28
- Published: 2024-02-01
- Granted: 2026-10-13
- Earliest claimed: 2021-04-14
- Assignees: Vivo Mobile Communication Co., Ltd.
- Applicants: Vivo Mobile Communication Co., Ltd.
- Inventors: Tingting Zhong; Zhenhua Xie
- Web page: https://patentgrep.com/patent/US12764616B2

## CPC

- H04W 36/0061: {of neighbour cell information}
- H04W 36/0007: {for multicast or broadcast services, e.g. MBMS (multicast or broadcast application services H04W4/06; resource management for broadcast services H04W72/30; connection management for selective distribution or broadcast H04W76/40)}
- H04W 36/0011: {for data sessions of end-to-end connection}
- H04W 36/08: Reselecting an access point
- H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72)

## Abstract

A transmission switching method, a terminal, and a network-side device are provided. The transmission switching method according to embodiments of this application includes: sending, by a source base station, a first indication to a network-side device, where the network-side device includes a target base station and/or a core network function, the first indication is used to request a terminal to hand over from the source base station to the target base station, the first indication contains service information of a first service, and the service information of the first service is used to determine whether the target base station is within or out of a service area corresponding to the first service.

## Claims

### Claim 1

A transmission switching method, wherein the method comprises:
sending, by a source base station, a first indication to a network-side device, wherein the network-side device comprises a target base station;
wherein the first indication is used to request a wireless terminal to hand over from the source base station to the target base station, the first indication contains service information of a first service, and the service information of the first service is used for the target base station to determine whether the target base station is within or out of a service area corresponding to the first service;
wherein after the target base station receives the first indication from the source base station, the method further comprises:
when the target base station receives a radio resource control (RRC) message sent by the wireless terminal after the wireless terminal generates the RRC message and when the wireless terminal determines that the target base station is out of the service area corresponding to the first service, the target base station performing at least one of the following based on the RRC message:
when the RRC message indicates the target base station to release resource corresponding to the first service, releasing the resource corresponding to the first service; and
when the RRC message indicates that the wireless terminal does not belong to a service group corresponding to the first service, sending an N2 message to a core network function, wherein the N2 message is used to indicate that the wireless terminal does not belong to the service group corresponding to the first service;
wherein the first service comprises local multimedia broadcast and multicast service (Local MBS), or comprises the Local MBS and MBS;
wherein the core network function comprises an access and mobility management function (AMF).

### Claim 2 (depends on 1)

The method according to claim 1, wherein the method further comprises:
when the source base station is uncertain whether the target base station is within or out of the service area corresponding to the first service, the source base station performing the step of sending a first indication to the target base station.

### Claim 3 (depends on 1)

The method according to claim 1, wherein before the performing the step of sending, by a source base station, a first indication to a network-side device, the method further comprises:
when the source base station determines that the target base station is out of the service area corresponding to the first service, the source base station performing at least one of the following:
determining not to send the first indication to the network-side device;
removing the service information of the first service from the first indication; and
sending a fifth indication to the wireless terminal, wherein the fifth indication is used to indicate that the wireless terminal does not belong to a service group corresponding to the first service.

### Claim 4 (depends on 3)

The method according to claim 3, wherein the source base station is an enhanced base station.

### Claim 5 (depends on 1)

The method according to claim 1, wherein after the step of receiving, by the target base station, the first indication from the source base station, the method further comprises:
when it is determined that the target base station is out of the service area corresponding to the first service, the target base station performing at least one of the following:
sending a second indication to the source base station, wherein the second indication is used to indicate that handover to the first service is rejected and/or the wireless terminal does not belong to a service group corresponding to the first service; and
sending a third indication to a core network function, wherein the third indication is used to indicate that the wireless terminal does not belong to the service group corresponding to the first service.

### Claim 6 (depends on 1)

The method according to claim 1, wherein after the step of receiving, by the target base station, the first indication from the source base station, the method further comprises:
the target base station sending a path switch request to a core network function, wherein the path switch request carries the service information of the first service.

### Claim 7 (depends on 1)

The method according to claim 1, wherein the target base station is an enhanced base station.

### Claim 8

A transmission switching method, wherein the method comprises:
receiving, by a core network function, a first indication from a source base station, wherein the first indication is used to request a wireless terminal to hand over from the source base station to a target base station, the first indication contains service information of a first service, and the service information of the first service is used for the core network function to determine whether the target base station is within or out of a service area corresponding to the first service;
wherein after the step of receiving, by a core network function, a first indication from a source base station, the method further comprises:
when it is determined that the target base station is out of the service area corresponding to the first service, generating and sending, by the core network function, a non-access stratum (NAS) message to the wireless terminal, wherein the NAS message is used to indicate that the wireless terminal does not belong to the service group corresponding to the first service;
wherein the first service comprises local multimedia broadcast and multicast service (Local MBS), or comprises the Local MBS and MBS;
wherein the core network function comprises an access and mobility management function (AMF).

### Claim 9 (depends on 8)

The method according to claim 8, wherein after the step of receiving, by the core network function, a third indication from the target base station, the method further comprises:
sending or determining not to send, by the core network function, a NAS message to the wireless terminal, wherein the NAS message is used to indicate that the wireless terminal does not belong to the service group corresponding to the first service.

### Claim 10 (depends on 8)

The method according to claim 8, wherein the second condition comprises:
the path switch request contains the service information of the first service; and
the target base station is out of the service area corresponding to the first service.

### Claim 11 (depends on 8)

The method according to claim 8, wherein, when the core network function rejects handover of the wireless terminal, the core network function add a PDU session identifier (session ID) of the first service in a handover command message.

### Claim 12

A transmission switching method, wherein the method comprises:
receiving, by a wireless terminal, a radio resource control (RRC) reconfiguration message from a source base station, wherein the RRC reconfiguration message is sent after the source base station sends a first indication to a network-side device, the first indication is used to request the wireless terminal to hand over from the source base station to a target base station, the first indication contains service information of a first service, the service information of the first service is used for the wireless terminal to determine whether the target base station is within or out of a service area corresponding to the first service, and the network-side device comprises the target base station;
wherein after the step of receiving, by a wireless terminal, an RRC reconfiguration message from a source base station, the method further comprises:
when it is determined, based on the RRC reconfiguration message, that the target base station is out of the service area corresponding to the first service, the wireless terminal performing at least one of the following:
generating and sending a NAS message to a core network function, wherein the NAS message is used to indicate that the wireless terminal does not belong to the service group corresponding to the first service; and
generating and sending an RRC message to the target base station, wherein the RRC message is used for either of the following:
indicating the target base station to release resource corresponding to the first service; and
indicating that the wireless terminal does not belong to the service group corresponding to the first service;
wherein the first service comprises local multimedia broadcast and multicast service (Local MBS), or comprises the Local MBS and MBS;
wherein the core network function comprises an access and mobility management function (AMF).