Distributed Storage Schemes for Controlling Data Availability in Wireless Sensor Networks

The high unreliability of sensor nodes decreases the data availability. The replica management systems can provide very high data availability in the distributed systems. Due to energy limitations, the biggest challenge is the placement and management of replicas in the sensor networks. This paper addresses the problem of introducing sufficient redundancy with minimal communication cost to a network such that the entire network data can be retrieved after a failure. We formalize the replica placement problem and using failure models, give the optimal placement equation. Because the optimal placement equation is the 0-1 integer program problem which generally is very difficult to solve, we simplify the optimization equation by implicit enumeration method. The proposed data distribute scheme reduces the communication cost and ensure data availability in wireless sensor networks.