Resilient sinks for long lived wireless sensor networks

Wireless sensor network is a set of autonomous sensor nodes dedicated to sense sizes of physical phenomena of a geographical area of interest. The sizes so collected are converted to numerical data to be transmitted to a specific node called base station or sink. After some appropriate processing, the data are sent out to a monitoring center. Therefore, a sink takes over a vital role in a WSN since it achieves an interface between the rest of the deployed sensor network and the end user. Consequently, a failed sink may abort the overall mission of the network. Due to their crucial functions, sinks must be designed and maintained to be robust enough in order to face trouble coming from the harsh environment wherein nodes are deployed. Thus, as a keystone of a WSN, sink has to be provided with ability to recover from failures. In this paper, we propose a protocol avoiding the sink to be a central point of failure, thus giving it the capacity for fault tolerance more significantly. This protocol allows error detection instantaneously and speedy error recovery. The results obtained from simulation, with TinyOS/PowerTOSSIM simulator, have been very convincing.