Retransmission or Redundancy: Transmission Reliability in Wireless Sensor Networks

As an application-driven network, wireless sensor network generally requires high data reliability to maintain detection and response capabilities. Although two approaches, which are retransmission and redundancy, have been proposed to enhance data reliability, the theoretical work is required to evaluate their impact on transmission reliability and energy efficiency. In this paper, we offer a comprehensive theoretical study on the packet arrival probability and average energy consumption for both approaches. Our analysis indicates that when loss probability remains low or moderate, erasure coding, a scheme based on redundancy, is more reliable and energy efficient than retransmission. However, the performance of erasure coding would largely deteriorate under high packet loss condition. We also demonstrate that its resistance capability against packet loss weakens as hop number increases. Furthermore, with the increase in redundancy, erasure coding has to sacrifice the advantage of energy efficiency for reliability.