Performance Analysis And Realization Of SIP-based Handoff Techniques

The features of next generation wireless networks are heterogeneous, real-time multimedia service and so on. These require a handoff scheme with very short delay and transparency feature to infrastructure. SIP meets these two requirements, so this paper focuses on SIP-based handoff techniques.We simply introduce some elementary knowledge and import SIP signaling retransmission and spare mechanism for retransmission failure to the existing numerical model, in order to make the formula more accord with the property of SIP handoff. Moreover, we combine the transmission delay and queuing theory to obtain acceptable handoff performance simulation model. With this model, we compare re-INVITE scheme, HMSIP scheme and B2BUA-dominant scheme using MATLAB. The results prove the advantages of soft handoff and meanwhile its shortcoming of high difficulty to implement. Thus, in this paper we suggest a user-dominant soft handoff scheme. Its performance is close to B2BUA-dominant scheme, and with more flexibility and more reliability. We establish a testbed to test the performance of user-dominant soft handoff scheme. And we modify the SIP transaction period to decrease the handoff delay and increase precision of measurement. At last, we analyze the two relationships, between wait time and network load and between wait time and RTP codec, based on simulation result.