Spherical Coordinate Routing for 3D wireless ad-hoc and sensor networks

While wireless networks are generally deployed in three dimensional environments, most geometric routing protocols are designed and evaluated with a focus on two dimensional space. In this paper, we present a connectivity based routing protocol in 3D space named Spherical Coordinate Routing(SCR), which exploits connectivity-based greedy forwarding for efficient routing paths and a spherical coordinate tree based recovery method to guarantee packet delivery. SCR can deploy multiple recovery trees simultaneously to enhance the routing efficiency and resilience against network dynamics. Simulation results show that the packet delivery ratio of SCR is 22% ~ 63% higher than that of BVR, LCR and NoGeo, at the critical node density range of 4 to 8. The amount of forwarding traffic required per packet delivery is considerably lower than protocols relying on scoped flooding based recovery. The SCR protocol can efficiently recover from topology changes due to clustered node failures, while maintaining excellent path stretch and traffic load performance in a 3D network topology.