Stable low-stretch routing scheme for wireless sensor networks with a large hole of complicated shape

The problem of routing with the presence of holes in wireless sensor networks has been studied for long and has resulted in a long list of sophisticated proposals and clever techniques that deal with various issues revolving around the existence of holes such as packet delivery guarantee and load balancing. However, most existing works have not entirely solved the issue of sustainment of near-hole sensor nodes, which tend to be energy exhausted by traffic concentrating on the hole’s border (due to the popularity of greedy routing). This issue gives rise to network instability where these nodes can die in numbers that would result in the undesirable enlargement of the hole and, thus, shortens the network lifetime. Moreover, there is a lack of strategies to tackle the case of near-hole nodes being the recipients or senders, especially for those nodes in cavern-like regions whose shapes are full of twists and turns. In this paper, our STABLE routing scheme is proposed to address the problem of routing with the existence of a large, complicated-shape hole in every aspect, regardless of where the senders and recipients are located. We propose to use the ball-rolling technique to compute an inner-margined area of a cavern, which helps to distribute traffic away from the hole boundary. Our experimental results show that our STABLE yields the longest network lifetime and highest load balancing compared to other well-known routing algorithms.