Design And Implementation Of A MAC Protocol Based On Coded Preambles In Low-Power Sensor Networks

Energy efficiency is one of the most important factors that affect the applicability of Wireless Sensor Networks (WSNs) in many practical scenarios. Many low power MAC protocols have been proposed in the past decade to improve the energy efficiency of radio operations, which cost most of the energy of sensor nodes. In these low power MAC protocols, preambles are widely used to wake up the receivers asynchronizely. However, the data delivery potential of these preambles has not been exploited. In this thesis, we propose COPE, which exploits the data delivery potential of preambles by encoding the preambles by network coding. COPE has two salient features. First, a passive receiver set selection scheme enables nodes to decide whether to receive the overheard preamble packets, without introducing extra communication overhead. Second, COPE supports multiple routing primitives, such as unicast and broadcast, making it be a versatile 2.5 layer between the low power link layer (layer 2) and the network layer (layer 3).The contributions of this thesis are summarized as follows:(1) For the first time, this thesis exploit the data delivery potential of preamble packets in asynchronized low power sensor networks.(2) This thesis propose COPE, a coded preamble design for improving the energy efficiency of low power sensor networks. COPE has two salient features. First, it does not introduce extra communication, improving energy efficiency significantly. Second, it is a versatile 2.5 layer, which support all three common routing primitives.(3) This thesis implement COPE and evaluate its performance in various network settings. We also propose a novel analytical model to analyze its performance. Results show that COPE achieves much higher energy efficiency compared with a traditional preamble based low power approach.