Progressive In-Network Reliability for Wireless Sensor Networks

This monolog considers the case of reliable data transmission in energy constrained Wireless Sensor Networks (WSNs). Low rate channel coding can increase reliability and eliminate the need of costly retransmissions of sensor data. However, low rate channel coding on end-to-end basis puts a considerable burden in terms of transmit energy on resource constrained sensor nodes. We propose a setup that progressively provides reliability as information traverses the multi-hop wireless sensor network. Precisely, we propose an Optimal Progressive Error Recovery Algorithm (OPERA) under which, individual intermediate sensors that are relaying data toward the base station, partially and optimally channel-decode the incoming packets as data reaches the final destination. We use iteratively decodable Low Density Parity Check (LDPC) codes in order to illustrate the efficiency of the proposed architecture. The proposed OPERA setup optimally distributes the decoding iteration budget over the entire network with minimal energy expenditure. We apply the OPERA framework to both still images as well as video streams and present an architecture for reliably transmitting video in WSNs.