Circle Path Based Sink Location Service for Geographic Routing Scheme

Geographic routing has been considered as an efficient, simple, and scalable routing protocol for wireless sensor networks since it exploits pure local location information instead of global topology information to route data packets. Geographic routing requires the sources nodes to be aware of the location of sinks. Most existing geographic routing protocols merely assume that source nodes are aware of the locations of sinks or can get the locations of sinks by some service. How can source nodes get the locations of sinks was not addressed in detail. In this paper, we propose a circle path based sink location service for geographic routing in wireless sensor networks. In this scheme, a source node sends a sink location query (SLQ) message to the predefined base node and sends another SLQ message to a node on the edge of the sensor network, thus generating a SLQ path; a sink node sends a sink location announcement (SLA) message along a circle path, the centre of the circle path is the predefined base node. By this way we can guarantee the SLQ path and SLA path have at least one crossing point. The node located on the crossing point of the two paths informs the source node the sink location. How to achieve this procedure in any irregular profile sensor network is another challenge of this paper. Simulation results show that our protocol is significantly superior to other protocols in terms of energy consumption and control overhead.