Method and device for managing security domain access information of migrated users

The method performed by a first client in a wireless communication system, the method comprising:

• transmitting, to a first server, a private call request for establishing the private communication with a second client;
• receiving, from the first server, a private call redirection message, wherein the private call redirection message includes information that the second client is migrated to the second server and a new service identifier (ID) of the second client;
• and
• establishing the private communication with the second client based on the private call redirection message,
• wherein the private call redirection message includes security domain access information including a key management server (KMS) uniform resource identifier (URI) associated with the new service ID of the second client.

A first server comprising:

• at least one transceiver;
• at least one hardware processor communicatively coupled to the at least one transceiver;
• and
• at least one memory, communicatively coupled to the at least one hardware processor, storing instructions executable by the at least one processor individually or in any combination to cause the first server to:
• receive, from a first client, a private call request for establishing the private communication with a second client;
• determine whether the second client is migrated from the first server to a second server with a new service identifier (ID) assigned by the second server;
• and
• in case that the second client is migrated from the first server to the second server, transmit, to the first client, a private call redirection message including information indicating that the second client is migrated to the second server and information on a new service ID of the second client,
• wherein the private call redirection message includes security domain access information including a key management server (KMS) uniform resource identifier (URI) associated with the new service ID of the second client.

A first client comprising:

• at least one transceiver;
• at least one hardware processor communicatively coupled to the at least one transceiver;
• and
• at least one memory, communicatively coupled to the at least one hardware processor, storing instructions executable by the at least one processor individually or in any combination to cause the first client to:
• transmit, to a first server, a private call request for establishing the private communication with a second client;
• receive, from the first server, a private call redirection message, wherein the private call redirection message includes information that the second client is migrated to the second server and a new service identifier (ID) of the second client;
• and
• establish the private communication with the second client based on the private call redirection message,
• wherein the private call redirection message includes security domain access information including a key management server (KMS) uniform resource identifier (URI) associated with the new service ID of the second client.