METHOD FOR PUBLISHING, QUERYING AND SUBSCRIBING TO INFORMATION BY A SIP TERMINAL IN A VoIP NETWORK SYSTEM, SIP TERMINAL, SIP APPLICATION SERVER, SIP INFORMATION CENTER AND VoIP NETWORK SYSTEM

A method for querying information by a SIP terminal in a VoIP network system, wherein the VoIP network system is deployed with a SIP information center for storing and providing at least the information;

• said method comprises:
• creating a querying request with query conditions embedded in at the SIP terminal;
• sending the querying request from the SIP terminal to the SIP information center via the SIP application server;
• querying the information according to the querying request at the SIP information center;
• and
• returning query results from the SIP information center to the SIP terminal via the SIP application server.

A method for subscribing to information by a SIP terminal in a VoIP network system, wherein the VoIP network system is deployed with a SIP information center for storing and providing at least the information;

• said method comprises:
• creating a subscribing request with subscribing conditions for subscribing to user-interested topic embedded in at the SIP terminal;
• sending the subscribing request from the SIP terminal to the SIP application server;
• monitoring whether there is new information published in the SIP information center which meets the subscribing conditions;
• and
• when there is new information of this topic published in the SIP information center, notifying it from the SIP information center to the SIP terminal via the SIP application server.

A SIP terminal, comprising at least one of the following:

• an information publishing unit configured to create a publishing request with information to be published embedded in;
• an information querying unit configured to create a querying request with query conditions embedded in;
• and
• an information subscribing unit configured to create a subscribing request with subscribing conditions for subscribing to user-interested topic embedded in.

A SIP application server, comprising at least one of the following:

• a publishing request processing unit configured to obtain information to be published from a publishing request received from a SIP terminal and forward it to SIP information center interacting with the SIP application server;
• a querying request processing unit configured to obtain query conditions from a querying request received from a SIP terminal and forward them to the SIP information center;
• and
• a subscribing request processing unit configured to monitor the update of the SIP information center and notify the new information in the SIP information center, which is subscribed by a subscribing request received from a SIP terminal, to the SIP terminal.

A SIP information center, comprising:

• at least one database for storing information;
• a database updating unit configured to update the at least one database based on information to be published which is received from a SIP terminal via a SIP application server;
• and
• a querying unit configured to query the at least one database for the information meeting query conditions received from a SIP terminal via a SIP application server.