MHD-CAR: A Distributed Cross-Layer Solution for Augmenting Seamless Mobility Management Protocols

The Next Generation Network (NGN) architecture is evolving into a highly heterogeneous infrastructure composed of a variety of Wireless Access Technologies (WAT). In such a technologically diverse network; one of the key challenges would be to ensure ubiquitous communication services to mobile entities, with varying mobility patterns and speed, irrespective of their location and/or the underlying WAT. This calls for devising efficient mobility management solutions that would provide location management and handover management services to mobile entities. The location management service is responsible for keeping track of the location of the mobile entities whereas the handover management service enables the mobile entity to change its point of connection in the Internet. The essential mandate of any efficient mobility management solution is to provide effective and fast location monitoring and updating services while enabling seamless inter-WAT handover. The notion of seamless handover implies handovers with minimum latency and packet losses. Providing seamless handover is an imposing challenge because the location update takes place after the successful execution of the handover. The handover process is executed at both the data link layer (L2) and at the network layer (L3) based on prescribed rules at these respective layers. The L2 handover process enables the mobile node (MN) to switch its link connectivity from its serving access point (AP) or base station to the new one. After successfully establishing link connectivity, the MN will then need to perform L3 handover process to make the MN IP capable on the new link. Till the completion of the handover, the MN is practically disconnected from the network resulting in loss of data. The amount of data lost depends on the handover latency, which in turn is a sum of delay incurred by handover procedure prescribed at L2 and L3 respectively. This implies that the latency of the L3 handover process is directly dependent on the latency of the L2 handover process and also on the timing of the provisioning of L2 triggers that will initiate the L3 handover process. Thus to develop seamless handover methodology, it is important to take into account the effect of L2 handover process on the L3 specified handover operations. This calls for devising cross-layer mobility management solution that will enable inter-layer communication 28