Analyzing the Effect of a Block FEC Algorithm’s Symbol Size on Energy Consumption in Wireless Sensor Networks

Abstract

This paper evaluates the effect of a block Forward Error Correction (FEC) algorithm’s symbol size on power consumption in wireless sensor networks (WSN). The WSN channels exhibit frequent bursty errors with a high average Bit Error Rate (BER) due to low transmission power, random deployment, and moving intermediate objects obstructing WSN communications. For resisting against the bursty errors, WSN would adopt a block FEC algorithm that restores more tainted bits than other kinds of FEC algorithms as errors become burstier since it recovers errors symbol-by-symbol not bit-by-bit. Even when the same amount of bits are allocated for FEC code, different FEC symbol size meaning different number of FEC symbols vary the packet error rate and the transmission energy over a given WSN. They also affect the computational energy since their decoding and encoding complexities depend on the number of FEC symbols per packet. The analytical evaluation based on long-term sensor traffic traces indicates that the appropriate FEC symbol size saves a sensor node’s energy consumption by up-to 85 % comparing to other sizes.