Method for obtaining device information of user terminals and communication service function entity

A communication service function entity having a processor and a memory coupled to the processor, comprising:

• a receiving unit 901, adapted to receive a device information obtaining request;
• and
• a sending unit 902, adapted to in response to a device information obtaining request, send the device information of a target user to a requesting terminal according to the target user ID which is carried within the device information obtaining request, wherein the device information obtaining request is authorized according to at least one of a presence information authorization rule and notification filtering policy of the target user, or according to a local subscription notification and authorization policy, wherein the device information comprises a device display-name of a terminal of the target user, which is defined for the terminal by the target user, and ongoing session state information in the terminal of the target user;
• an obtaining unit, adapted to obtain the device display-name of a terminal of the target user, and the ongoing session state information in the terminal of the target user;
• a storing unit, adapted to associate an ID of the target user, and store the device display-name of the terminal of the target user, and the ongoing session state information in the terminal of the target user obtained by the obtaining unit as the device information of the target user;
• wherein the communication service function entity obtains the ongoing session state information when the state of the session joined by the user terminal is changed, associates the session state information with a user ID and stores the session state information in the device information of user terminals;
• and
• the sending unit, adapted to extract the device information of the target user from the storing unit according to the target user ID.