An efficient performance comparison of two cross-layer service discovery designs in MANET: BF-SD-ZRP versus SD-OLSR

Users of today´s networks expect certain services from the network. Indeed one of the purposes of the network is to enable nodes to access remote services and resources not locally available. Given the significance and potential benefits of MANETs, it is necessary to design robust protocols which ensure that users of such networks are able to find the services they require. Due to limited computing power, scarce bandwidth, high mobility and the lack of a central coordinating entity, service discovery in MANETs is a challenging task. The great majority of service discovery protocols developed for MANETs deal with the above issues at the application layer. In this paper, we focus on integrated approaches of service and route discovery. We develop an integrated service discovery protocol, called BF-SD-ZRP combining several optimization techniques: the use of Bloom Filter compression scheme providing an optimized description of service information. The subsequent piggybacking of service information into ZRP routing messages, taking advantage of its intelligent bordercasting mechanism to propagate information to remote nodes. A Caching scheme is used to obtain further reductions of both overhead and latency. We present and examine our simulation results for both BF-SD-ZRP and SD-OLSR cross-layer protocols in order to demonstrate the efficiency of our scheme in terms of overhead reduction and service discoverability using the scalable network simulator Jist/Swans.