SHORT: A Simple HOle-Resistant Technique for Reliable Geocasting in Location-Free Wireless Sensor Networks

In general, geocasting is more unlikely to be guaranteed in wireless sensor networks if sensor nodes have no location information. Moreover, environmental holes (e.g., physical obstacle or area without the functionality of communication) significantly cause a low packet delivery ratio. This paper proposes a simple hole-resistant technique, called SHORT, to achieve reliable geocasting in location-free wireless sensor networks (LF-WSNs). Sensor nodes in LF-WSNs are recognized by their direction and hop distance. The proposed SHORT aims to select appropriate candidate forwarders to relay received geocast packets using a forwarding probability, which is derived from nodes´ direction and hop distance. With the aid of multiple forwarders, SHORT can efficiently resist environmental holes. Simulation results validate that the proposed SHORT outperforms the simple direction-based forwarding scheme in packet delivery ratio under LF-WSNs with environmental holes.