Transport Protocol For Field Study Of Large Site Secured Wireless Sensor Networks Multi-gateway Data

Wireless Sensor Networks (WSN) is used to monitoring the wild wide sites, it has become an important method in the protection of cultural sites, for it is effective to help us to understand the influence and regulation of natural differentiation, fission of large-scale cultural sites, and acquire the man-made destruction of sites in real-time. There are many technical problems and challenges should be solved in the application of monitoring the large sites (such as Great Wall) that are located in the wide, sparse, without power supply and communication facilities, complex geographical areas.Based on the application of large scale cultural sites monitoring, we brought the WSN into the application. We proposed a state estimation based data transmission protocol for multiple gateways (SEDT), SEDT is focused on problems of data transmission reliability that is reduced by random dormancy data gathering gateways. The specific research work includes the following aspects:1) We proposed a state estimation model for data gathering gateways to select gateway. We analyzed the charging and consumption process of data gathering gateways that installed solar panels and wind power generation equipments. We studied the relationship between network load and data gathering gateway’ s state, and presented an estimation model that is adaptive to the environment. Sender nodes could estimate the state of data gathering gateways at any certain time point via this model, and then select the final optimal destination to guarantee the data transmission reliability.2) We designed a state estimation based data transmission protocol for multiple gateways (SEDT). SEDT divided the data transmission into three continuous parts. First, sensor nodes determine the candidate data gathering gateways set according to the control message send by data gathering gateways; second, we proposed a probabilistic method that has sensor nodes estimated the delay to each data gathering gateway, and then use the estimation model to estimate the working probability of each data gathering gateway at any certain time point when the packets arrive, select the optimal data gathering gateway through the "virtual ruler"; last, the opportunistic routing is used to transmit the data. Simulation results show that SEDT can balance network load, improve the delivery ratio and reduce energy consumption.