Below Cross-Layer: An Alternative Approach to Service Discovery for MANETs

Service discovery protocols for mobile ad hoc networks attempt to overcome the inability to locate resources presented by networks in which prior knowledge of node identity and capability is not available. Existing approaches continue to rely on underlying address-based routing protocols in order to communicate with discovered services. These two-tier approaches generate routing overheads which negatively impact on performance and network scalability. As high-powered mobile computing devices with wireless connectivity become increasingly ubiquitous, the need for routing protocols which can operate at increased network densities becomes more acute. Cross-layer approaches to service discovery in MANETs have attempted to optimize the discovery process through direct integration with underlying routing protocols, however additional steps are necessary to improve service discovery performance, network scalability and application throughput. This paper describes the Service Discovery and Routing Protocol (SDRP), a novel service-oriented routing protocol for MANETs. This protocol eschews the use of network-wide unique addresses or underlying address-based routing protocols and focuses instead on routing only to and from nodes which provide services. A comparison with existing approaches demonstrates that this approach improves discovery success rates and application throughput at higher node densities.