A Layer 3 Movement Detection Algorithm Driving Handovers in Mobile IP

The evolution and the spreading of wireless access technology and the consequent increase of user mobility will make handover procedures critical for the provision of Quality of Service in the next generation wireless Internet. Often, layer 3 handovers are supposed to be driven by access layer procedures. In this way, the movement detection delay can be reduced, but at the expenses of making the Mobile IP protocol dependent of lower layer implementations. Furthermore, this approach may not be effective when users roam among heterogeneous networks. Nevertheless, movement detection algorithms, which operate at the Mobile IP layer, imply appreciable delays, usually intolerable for real time services. In this paper, we propose a Mobile IP handover scheme based on a novel movement detection algorithm at layer 3, able to timely manage migrations by exploiting advertisements losses, combined with a two-timers mechanism. We analyze the performance of our algorithm in terms of handover delay and throughput, and we show that our solution is able to decrease the movement detection delay as much as 47% with respect to other literature solutions that pursue similar approaches. In addition, this feature implies also higher values of the throughput seen by the TCP layer.