The Research On The MAC Protocol In Wireless Sensor Networks For Electronic Borderline

The MAC (Medium Access Control, MAC) protocol is one of the key network protocols to ensure the wireless sensor networks to communicate efficiently. In the electronic borderline of wireless sensor networks, because the data collected by the sensor nodes must be reported to the sink node instantaneously to realize the surveillance of the key areas, reducing communication latency and decreasing energy consumption are the key problems that need to be solved by the MAC protocol.Based on the demand of the wireless sensor networks for the electronic borderline, this paper analyzed and tested the MAC protocols, and proposed a cross-layer energy-efficient MAC protocol and an ameliorate algorithm.Firstly, the wireless sensor networks and MAC protocol are introduced, and the typical MAC protocols of wireless sensor networks are studied. Besides, the characteristics of different types of MAC protocols and advantages or disadvantages of specific MAC protocols are analyzed and detailed compared. In the forepart of our work, aimed at the requirements of delay and energy-saving in the electronic borderline, SP-MAC protocol is proposed. B-MAC protocol being selected for reference, by setting a small testing network, the performance of delay and energy-saving of the two MAC protocols is tested and analyzed. The experimental result shows that, in different load conditions of wireless sensor networks, SP-MAC protocol performed better than B-MAC protocol in the area of delaying and energy-saving.To solve the network load imbalance problem founded in testing, based on the SP-MAC protocol, NSP-MAC protocol is proposed. The NSP-MAC protocol adopts the idea of cross-layer design, and has the function of routing protocol. An algorithm to select transmiting neighbor-nodes is proposed in NSP-MAC protocol. The algorithm selects neighbor-nodes with most residual energy or smallest transmit length to transmit the messages. Hence, the NSP-MAC protocol can effectively improve the network load balancing and prolong the network's survival time.Lastly, we implement the NSP-MAC protocol in the MANTIS OS system, and the capability of NSP-MAC protocol is tested. The result shows that it performs better than the SP-MAC protocol in energy-saving and can meet the demand of electronic borderline application well.