Distributed geographic service discovery for mobile sensor networks

Many of the recent sensor network applications assume node mobility. The service provisioning protocol should therefore be designed to be stateless and scalable for continuously changing link states of typical mobile sensor nodes. In this paper, we propose DSDP, Distributed Service Discovery Protocol, for mobile sensor networks. DSDP organizes the network area into hierarchical regions to reduce service update cost. Regions at the lowest hierarchy cover a two-hop range area, and nodes freely move within the larger area without updating the service coordinators. Due to the low hierarchy architecture, the increased size of the minimal regions helps to reduce the runtime overhead. Node mobility is specifically considered in DSDP. Depending on the nodes' mobility, nodes in DSDP work as service coordinators for requested services, and the discovery protocol runs in a distributed manner to lessen the overhead. Both the simulation and experimental results show that the proposed mechanism achieves a high service query success rate and low service update overhead in mobile sensor networks.