| Wireless Sensor Networks(WSNs) are multi-hop networks that monitor the environment through the deployment of wireless sensor nodes in a certain area. Due to the use of battery-powered wireless sensor nodes,each single node’s energy is limited, while the harsh environment nodes are deployed, each wireless sensor node maybe failed or captured at anytime during the whole life of network. so security and energy constrained are two of key factors in wireless sensor networks.Currently in wireless sensor networks, the using of data compression techniques and clustering structure can reduce the number of data transmission and increase the network lifetime. But the improving of network performance heavily depends on the data compression ratio and cluster size and other factors. Meanwhile the traditional key distribution protocol can’t be used in wireless networks due to the restriction of sensor node’s energy resources. So focus on the problem of energy consumption of mobile sensor networks and traditional key distribution protocol can’t support nodes moving, we do the following major tasks:Through introducing second cluster head node into wireless sensor network, we proposed two-layer cluster wireless sensor network architecture model. Based on this model, we analysis the total number of data transmission in two-layer cluster network, obtained the minimize of total number of data transmission and the number of best first-layer and second layer. And then we combine set cover problem, propose a cluster head selection algorithm in two-layer cluster network model. Finally, compare with one-layer cluster wireless sensor network architecture model, the result of our model is better than the best result of one-layer model about the number of data transmission and data compression ratio.Based on the two-layer cluster network model, we propose a two-layer key distribution protocol(T-L protocol). This protocol can well adapt our two-layer cluster network model. At last we analyzed the security of our protocol and the average energy consumption of single node in our pro tocol. Compare with protocol of LEAP, the average energy consumption of single node is smaller than protocol of LEAP. |
