Abstract
Power consumption represents one of the most constraints which affect the design of WSNs, leading to various protocols and algorithms aimed at minimizing the power consumption and extending batteries' lifetime. Sensor nodes in a WSN transmit their periodic packets continuously to cluster head nodes (receivers) which are responsible for processing and transferring packets to another parts of a network. In fact, cluster head nodes in WSNs most often consume a large amount of power due to the necessity to decode every received packet regardless of the fact that the transmission may suffer from packets collision which impede the network performance. Therefore, in the receiver side of WSNs current collision detection mechanisms have largely been revolving around direct demodulation and decoding of received packets and deciding on a collision based on some form of parity bits for error control. Full decoding of received packets with error control bits at cluster head nodes can achieve an efficient usage of network capacity, however, such an approach represents a major burden on power-constrained sensors. In this paper, we propose novel power efficient and low complexity techniques which achieve a significant power saving at the expense of low throughput losses. Based on studying the received packets, cluster head nodes can make a fast decision to detect a collision without the need for full-decoding of the whole received packets. Theoretical and simulation results show that our proposed Pilot Periods (PP) techniques can significantly reduce the computational complexity as well as the power consumption over existing Full-Decoding (FD) algorithms.