On Performance of 3GPP Service Triggering Mechanism in IMS Network

To determine the potential signaling traffic reductions, the session establishment procedures were investigated. The investigation showed that, the S-CSCF (Serving Call Session Control Function) is the major bottleneck in IMS (IP Multimedia Subsystem) network. And then the modeling of 3GPP (3rd Generation Partnership Project) Service Triggering Algorithm (STA) in IMS was presented. The session setup delay was employed as the measurement to investigate the performance of the ATA (Application Triggering Architecture) and S-CSCF. Analytical results showed that, the number of the ASs, the use of the subsequent Filter Criteria (sFC) and the arrival rate have heavy impact on the session setup delay. The results will be useful in constructing IMS network. At last, we proposed several possible solutions to reduce the session setup delay decrease the load of the S-CSCF and improves the QoS (Quality of Service) of IMS network.