Availability Considerations for Wireless Sensor Grids

In this paper, we derive and analyze network availability for sensor grids by considering an elaborate energy consumption model. Sensor grids that form chain topologies are compared for two widely known grid traversal models, namely staircase and Delannoy number. Based upon the mathematical model, we analyze two sleep modes, viz, synchronous and asynchronous for their effects on the network availability of sensor grids with regard to energy conservation and packet loss. We also propose a non-uniform, asynchronous sleep scheme in sensor grids which allows nodes to sleep in a manner such that nodes closer to the gateway sleep less than the nodes in the fringes. The performance results show that the proposed scheme prolongs network availability effectively in sensor grids.