Sensor networks are large-scale distributed sensing networks comprised of many small sensing devices equipped with memory, processors, and short-range wireless communication radio. Instead of broadcast-based routing protocols, in this paper we propose a novel energy-efficient routing protocol, which is called Straight Line Routing Algorithm1 (SLR), for wireless sensor networks. To achieve the routing task without broadcasting, the source host constructs the event path and the sink host constructs the query path respectively. That is, the routing path is found as the query path and the event path first intersect. Moreover, the SLR is able to build both the query path and the event path without any help of the geographic information.

We evaluate the performance of Straight Line Routing and Rumor Routing protocols through extensive simulations. The simulation results indicate that compared with Rumor Routing, the SLR can save more energy consumption, provide better path quality, and improve the successful ratio of routing as well.