Research And Implementation Of Energy-efficient MAC Protocols In Wireless Sensor Networks

Wireless sensor networks is composed of a large number of distributed sensor nodes that are densely deployed either inside the phenomenon or very close to it. These sensor nodes organize themselves into a multi-hop wireless network and cooperate to deliver collecting data to sink nodes. As sensor nodes are likely to be battery powered, and it is often very difficult to change or recharge batteries for these nodes, reducing energy consumption is the primary goal in wireless sensor networks design. This thesis is based on the National Development and Reform Commission CNGI R&D/industrialization and experimentation/application demonstration project—"IPv6 wireless sensor networks nodes", focusing on energy-efficient MAC protocol of wireless sensor networks. 1, Based on the analysis of the factors which affect the energy-efficiency of contend-based MAC protocol of wireless sensor networks, the key technique issues of energy-efficient MAC protocols are summarized, including sleeping mechanism, collision avoidance, backoff technique etc.2, An energy-efficient MAC protocol using routing information for wireless sensor networks—R-MAC has been presented, adapted to the major traffic characteristic of wireless sensor networks. Simulation results show that R-MAC has better energy saving performance in terms of decreasing idle listening, collision avoidance and control overhead compared with IEEE802.11DCF and S-MAC.3, Demonstrate the reasons of designing the simple energy-efficient MAC protocol on IPv6 wireless sensor networks nodes, and implement this MAC protocol on self-made IPv6 wireless sensor networks nodes. The debugging of this energy-efficient MAC protocol and the interface testing between the modules has already been completed, with application traffic loading on the MAC module communicating well.4, More research has been done about collision increasing, which is caused by the introducing of sleeping mechanism. An improved scheme is described, in which the receivers contend for receiving channel firstly, resulting in decreasing the number of senders and fewer collisions happened.