Abstract text

A method and a system for lawfully intercepting a value-added service in an IP multimedia subsystem (IMS) are provided. In the present method, a service subscription information is sent to a first information delivery module when a suspect is registered to an IMS network. A service triggering information is sent to the first information delivery module when the value-added service subscribed by the suspect is triggered. Furthermore, when the value-added service is provided, an intercept related information (IRI) is sent to the first information delivery module according to the characteristics of the value-added service. As a result, the suspect who is using the value-added service in the IMS can be lawfully intercepted according to the information collected by the first information delivery module.