Performance Evaluation of the Push-Mode-Multicast based Candidate Access Router Discovery (PMM CARD)

In order to provide nomadic users with QoS-enabled services, advanced mobility management will prove to be of fundamental importance in the future Internet. It has been widely recognized that the basic Mobile IPv4/v6 protocols could perform poorly, especially with QoS-demanding applications. One of the main steps to achieve seamless handover is the quick discovery of the surrounding wireless coverage at each access router (AR), i.e., the discovery of IP addresses and service capabilities (SCs) of candidate access routers (CARs) to hand over to. The rapid knowledge of IP addresses allows mobile nodes (MNs) to speed-up the handover process, whereas information about SCs are important for the selection of the most appropriate wireless access (target access router, TAR) among the set of CARs, according to a given criterion (e.g., load balancing). In this paper, we first describe the candidate access router discovery (CARD) solutions proposed within the framework of the IETF SEAMOBY WG, which has inspired research in this field. Then, we propose the distributed pushmode- multicast based CARD (PMM CARD) approach and compare it with the IETF proposals. The novelty of our solution is the use of push-mode multicast transmissions, which enables an efficient distribution of CARD information within the network, together with a significant reduction in latency due to explicit queries to a remote entity. Then, we develop a theoretical model to compute the signaling burden associated with different CARD solutions. Our analysis shows that, even though the amount of signaling required to implement all CARD approaches is generally low, our approach gives a certain improvement over the IETF proposals in terms of the average signaling load. In addition, the results obtained by a simulation campaign show the effectiveness of the PMM CARD solution in terms of the time needed by ARs to discover the surrounding wireless coverage