Research On Optimization Of MAC Layer Protocol For Wireless Sensor Networks

This paper proposes improvement of the MAC layer protocol of wireless sensor network based on the research of the 802.11MAC protocol in different applications.The requirements of performance index are different in different applications,the normal data transmission applications requires low energy consumption of sensor nodes to improve the survival time,large-scale concurrent data recovery business requires increased throughput rate to reduce the transmission time.This paper optimizes the 802.11 MAC protocol from two aspects of reducing energy consumption and improving data transmission rate,and improves the performance of MAC protocol in two different applicationsFirst,the sleep mechanism is added to the normal data transmission to reduce the energy consumption of the sensor nodes.Secondly,based on the mechanism of the sleep,the traffic sensing module and the dynamic mechanism of adjusting sleep time by rate of flow are added to form a low power MAC protocol which has the function of traffic sensing.Then,according to the specific characteristics of the large-scale concurrent data recovery business,continuous transmission mode of the data packets is achieved to reduce the control overhead and increase throughput rate.Finally,the collision avoidance mechanism is adjusted according to the continuous transmission mode of the data packet,and the fast transmission mode of data packets is realized.In this paper,the traffic aware dynamic duty cycle low power MAC protocol and the fast transmission mode of data packets based on 802.11MAC protocol is realized.Compared with the original protocol,the significant performance improvement is shown in two aspects:energy consumption and throughput.