Performance of intersegment handover protocols in an integrated space/terrestrial-UMTS environment

The universal mobile telecommunications system (UMTS) will deliver a convergent network incorporating cellular, cordless, wireless local loop, and satellite technologies. In this paper, a signalling protocol for intersegment handover (ISHO) in an integrated space/terrestrial-UMTS environment is presented. After discussing a number of possible ISHO scenarios, backward mobile-assisted handover (HO) incorporating signaling diversity is chosen as the most appropriate ISHO scheme. Based on the generic radio-access network (GRAN) concept and by using a satellite-UMTS network architecture and functional model, the derivation of an ISHO protocol is presented. The performance of this protocol is analyzed and evaluated in terms of the service interruption time, execution signaling time, and the end-to-end signaling time. Simulation results show that, in agreement,vith the GRAN concept, the service interruption time is independent of the signaling protocol and depends only on the satellite round-trip delay and the radio interface characteristics. The interarrival rate of the ISHO requests affect the performance of the protocol only when the value of the mean service time is increased. However, even in such a situation, the performance of the protocol is still considered acceptable.