Minimal Marking of Trap-Regions for Efficient Greedy Forwarding in WSNs
Rajesh Sharma, Lalit Kumar Awasthi, Naveen Chauhan · INTERNATIONAL JOURNAL OF NEXT-GENERATION COMPUTING · 2016
Geographic routing has emerged as a promising routing paradigm for Wireless Sensor Networks (WSNs). Localized operation, stateless nature, and ability to operate in absence of unique node addresses, are some of the characteristics that make geographic routing particularly suitable for WSN applications. Greedy forwarding is a simpler and efficient form of geographic routing in which a packet is forwarded to a neighboring node that makes maximum positive progress towards the destination. However, in the presence of communication voids, greedy forwarding may fail at some dead-end – a node that does not have any optimal neighbor for greedy forwarding. The dead-end situation is usually handled by switching to some other supplementary routing methods like flooding, perimeter routing, or face routing, which are highly inefficient and hence should be avoided whenever possible. The overall performance of geographic routing methods which utilize greedy forwarding can be significantly improved by denying a packet originating in Greedily-Routable-Region (GRR) to enter into a dead-end region during routing. In this work, we propose a simple yet effective method called Minimal Marking of Trap-Regions (MMTR) for maximizing the GRR in WSNs. MMTR performs the on-demand marking of minimum nodes of a trap-region so as to transform a WSN into a dead-end free network for greedy forwarding. The proposed solution also addresses the hotspot problem observed along the border of dead-end region.