Research And Design On Energy Balancing In Low-Duty-Cycle MAC Protocol

In recent years, the development of Wireless Sensor Network is huge. The application of Wireless Sensor Network in National Military, Industry and Agriculture controlling, and Government Monitoring is ordinary. However, Wireless Sensors have limited battery life, which has been a bottleneck of the working time of Wireless Sensor Networks. At the same time, the working condition of Wireless Sensors is very hash, so once some of the Wireless Sensors are dead of power, the available sensors in the network are less, the life of the entire WSN is infected. So, controlling the death rate of the network is also very important.Leach protocol is a kind of TDMA based WSN protocol,TDL-MAC(TDMA based Distributed Low Death Rate Medium Access Control). Leach search for different Cluster Heads in every passing of the data from the nodes to sink node. Due to the changing of Cluster Heads, the passing ways are changed, averaging the data load among the different nodes, changing the fixed passing way.Low-Duty-Cycle Protocol is a kind of protocol that arranges the nodes to sleep periodically, reducing the energy cost while there is no data transmission. There are two kinds of Low-Duty-Cycle protocol:"Preamble Sample"based Low-Duty-Cycle and TDMA based Low-Duty-Cycle. However, none of the proposed protocols have a kind of way to balance the nodes energy cost. So, in this thesis, we propose TDL-MAC(TDMA based Distributed Low Death Rate-Medium Access Control), to address this issue.In this thesis, we proposed a kind of Low-Duty-Cycle protocol controlling the energy cost in Wireless Sensor Networks, and compared it with the currently proposed protocols. Based on L-MAC, TDL-MAC added Leach-like nodes energy balancing mechanism, addressing the shortage of energy balancing problem. Energy cost and collision avoidance is also better than L-MAC.The realization of energy balancing is in route layer, optimizing the choice of route based on the remaining energy of every living WSN nodes, avoiding the nodes who has less energy costing more energy transmitting lots of data; Collision avoidance algorithm is realized by recording the slot occupation of the two jump nodes, avoiding both nodes sending to the same node at the same time. Energy optimization is adding destination address in the control package, avoiding the receiver to costs extra energy receiving unnecessary packages and abandoning them shortly after.Simulation results shows that TDL-MAC protocol can effectively slowing the death speed of WSN nodes, lowering the nodes energy costs. Comparing to L-MAC, the proposed protocol needs longer transmission latency, but tolerable.