Transmission switching method, terminal, and network-side device

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).

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).