Low Duty Cycle Wireless Sensor Networks Broadcast Routing Protocols

With the advance of micro-sensor technology, RFID technology and the wireless communication technology, information industry has entered the 3rd wave represented by "Internet of Things" and the wireless sensor networks. The human society is about to enter into a new era in which not only people can communicate with people and objects, but also objects can communicate with objects. The imagination of "Sense China", "Smart Earth" will come true. As the pioneer of the third wave, wireless sensor networks will be widely used in military defense, industrial control, transportation, medical etc.This thesis focuses on the research of broadcast routing protocol in low duty-cycled wireless sensor networks. The main contents are as follows:First, this thesis briefly overviews the architecture of wireless sensor networks, components of nodes and the two listening modes of low duty cycle MAC mechanism. Based on the background introduction, this thesis analyzes the energy and latency problems in low duty-cycled broadcast and gives guidelines for low duty-cycled broadcast protocol designing. In addition, this thesis does a literature survey on present low duty-cycled broadcast protocols and points out that these protocols have ignored the fact of unbalanced energy cost of nodes, which provides the motivation of designing our algorithm.Second, this thesis proposes a nodal-power-aware low duty-cycled broadcast protocol, which is called NPAB. NPAB allows nodes locally to maintain their neighbors'information. Based on the information, it dynamically schedules forwarding decisions to achieve balance of nodes' energy consumption and low broadcast latency. NPAB also designs an effective backoff strategy to reduce forwarding decision collision, which further conserves nodes'energy. Through the simulations, this thesis proves the effectiveness of NPAB in reducing broadcast latency, balancing nodes'power and prolonging network lifetime.