Post failure recovery of virtual coordinates in wireless sensor networks

Virtual Coordinate (VC) based algorithms do not use physical coordinates for addressing, and thus possess many advantages for large scale sensor networks. They rely on the validity of VCs of nodes. VCs are affected by events such as node failures which are unpredictable and inevitable in WSNs. This degrades the performance of the algorithms and may even reduce overall life of the network. A distributed algorithm is presented for fault detection and recovery of VCs due to node failure. Consistency of VCs is used to detect failures and affected VCs are recovered without the need to regenerate VCs by flooding the entire network. Performance of the VC repair algorithm is evaluated under different conditions. VC repair packets propagate in localized neighborhoods, the extent of which adapts to the nature of the failure. This helps to attain efficient performance for all network sizes. The algorithm helps the network recover gracefully from degradation in performance in response to sudden node failure patterns. It also helps enhance the performance of all the operations dependent on VCs and their validity.