mobile IP and SIP were used as mobility man-agement protocol in network layer and application layer
respectively.It was very inefficient when performing AAA op-erations in mobile IP and SIP independently.To solve this problem
proposed an optimized scheme
named Optimized AAA Procedure of Integration of Mobile IP and SIP(OAPIMS).Under the new AAA protocol
DIAMETER
it optimized signaling procedure of the two protocols while performing mobility registration.So it reduced time of round trips of sig-naling exchange and improved efficiency.Analysis indicates that this scheme can reduce signaling cost
time delay and improve system performance significantly.