An efficient void-resolution method for geographic routing in wireless sensor networks

Abstract

Wireless sensor networks consist of many sensor nodes which have sensing, computing, and wireless communication capabilities. Due to the need of sensor nodes for various unattended monitoring applications, they are expected to be more prevalent as major sources in ubiquitous computing. Wireless sensor devices, however, typically have serious energy constraint i.e., limited battery power lasting only from several days to months. Thus, energy-efficiency should be considered a primary factor in developing sensor network applications. Especially, an efficient technique is required to transport data across a sensor network because energy consumption in data communication is much greater than that of local computation. Geographic routing is an attractive choice for routing data in wireless sensor networks because of lightweight and scalable characteristics. The problem of geographic routing is that messages may be routed to a dead end. The void may be a disaster area where all sensors are destroyed, or it may be a bay where the sensors cannot survive. Once a message is routed to the dead end, it cannot proceed any further. Most geographic routing protocols include a void resolution method to detour a void area that has no active sensor. The previous solutions commonly use the right-hand rule for void resolution. However, the path produced by the right-hand rule is not energy-efficient in many cases. Under certain ideal conditions, geographic routing works correctly and efficiently. The most commonly used geographic routing protocols include greedy forwarding coupled with face routing. Existing face routing algorithms use planarization techniques that rely on the unit-graph assumption. In real world, many conditions violate the unit-graph assumption of network connectivity, such as location errors, communication voids and radio irregularity, cause failure in planarization and consequently face routing. We propose an efficient void resolution method, called V...