Research On Concurrent Transmission Mechanism Based Interference Model In Wireless Sensor Networks

Wireless sensor network is a kind of multi-hops and self-organizing wireless network,deployed in the monitoring area by a large number of sensors on the wireless communication mode.In order to maintain the high fidelity of the monitored object and the real-time continuity of the original data,sensor nodes need to produce a large amount of data,and transmit bulk data to a sink node or gateway.Since the common CSMA-based protocols and TDMA-based protocols cannot meet the requirements of low latency and high throughput in bulk data transmission,the domestic and foreign scholars have devoted themselves into the research on concurrent transmission,having put forward lots of classical concurrent transmission mechanism.System throughput is one of the most important indicators in evaluating the performance of transmission system.In order to measure the throughput of concurrent transmission system more accurately,we firstly analyze the process of sensor nodes sending a packet in detail,and determines the maximum throughput value of a single link.Then a method,which uses hardware capture to control sending time of a packet,is proposed.The result of multiple experiments has proved that not only the SINR but also the transmission time can affect the packet acceptance rate.Finally,two concurrent transmission methods are proposed,which use hardware capture to sync the time of concurrent transmission nodes.Through the theoretical analysis and experiments,compared with SINR-based method,both of two methods improve the throughput of concurrent transmission system in two interfering links dramatically.Firstly,we take C-mac as an example to analyze the shortage of current interference model based concurrent transmission mechanism.The design of C-mac only considers the impact of SINR rather than sending time on the packet reception rate.Then on the base of the methods mentioned above,we present BCT,a new Bulk Data Concurrent Transmission Mechanism based on Transmission Time.BCT estimates the packet reception rate instead of exchanging RTS/CTS with the receiver,and uses the result of traffic snooping and concurrency checking to determine the time of access channel.On the premise of ensuring that the current transmission cannot be affected,BCT improves the probability of concurrent transmission of nodes.Finally,the result of a comparison experiment between BCT and C-mac shows that,BCT greatly improves the throughput of concurrent transmission system and reduces the total convergence time.