FADS: Circular/Spherical Sector based Forwarding Area Division and Adaptive Forwarding Area Selection routing protocol in WSNs.

Without maintenance overhead make beaconless geographic routing protocol become an attractive routing scheme for wireless sensor networks (WSNs), however, without the knowledge of topology may result in high collision rate. In this paper, we firstly analyze the reason of CTS (Clear-To-Send) collision and classify it into Same-Slot collision and Distinct-Slot collision. Then, we proposed a novel routing protocol, Circular/Spherical Sector based Forwarding Area Division and Adaptive Forwarding Area Selection (FADS), which can avoid Distinct-Slot collision, reduce the probability of Same-Slot collision, and realize dynamic load balancing. 1) Forwarding area division ensures that every node within the same forwarding subarea is capable of hearing one another, thus avoiding Distinct-Slot collision. 2) Selecting forwarder from one of subarea decreases the number of contenders(candidates), hence the probability of Same-Slot collision is reduced. 3) Adaptive forwarding area selection dynamic channelizes the traffic to each subarea, thus realizing dynamic load balancing. Compared with related protocols, no matter in the 2D or 3D scenario, simulation results show the excellent performance of FADS in terms of packet delivery ratio, End-to-End latency, and energy consumption per packet, especially in dense networks and congested networks.