Mobility management for highly mobile users and vehicular networks in heterogeneous environments

With the recent developments in wireless networks, different radio access technologies are used in different places depending on capacity in terms of throughput, cell size, scalability etc. In this context, mobile users, and in particular highly mobile users and vehicular networks, will see an increasing number and variety of wireless access points enabling Internet connectivity. Such a heterogeneous networking environment needs, however, an efficient mobility management scheme offering the best connection continuously. In this paper, a mobility management architecture focusing on efficient network selection and timely handling of vertical and horizontal hand-overs is proposed. The solution is based on Mobile IP where hand-over decisions are taken based upon calculations of a metric combining delay and delay jitter. For efficiency reasons, the frequency of binding updates is dynamically controlled, depending on speed and variations in the metric. The dynamic frequency of binding updates helps the timely discovery of congested access points and cell edges so as to allow efficient hand-overs that minimize packet drops and hand-over delays. Results show that the overall signaling cost is decreased and changes in networking conditions are detected earlier compared to standard Mobile IP.