| 摘要 |
<p>A Session Initiation Protocol (SIP) application server (216) is connected to an SGSN (208) by a SIP user agent (214). The SIP user agent (214) supports the SIP protocol. The system is implemented using a GPRS Attach/Detach state model and a GPRS PDP context state model. When relevant detection points in these state models are encountered, the SGSN (208) provides an indication to the SIP User agent (214), which will determine the necessary action, i.e., trigger the network event to the SIP application server (216), where service logic is invoked and executed. SGSN (208) requested PDP context activation capability is added in order to support push services from the SIP application service. Operator owned PDP context is added in order to provide free services for the mobile end users. <IMAGE></p> |
