Research On Polling-Based MAC Protocol For Wireless Sensor Network

Wireless sensor network is an intelligent information system which includes the function of information acquisition, transmission and procession.It is a hot topic in the field of information today. It changes the interaction of human and physical world and improves the human perception of objective world. It is widely used in industrial monitoring, telemedicine, home automation, battlefield intelligence gathering and other occasions.MAC protocol for wireless sensor network that medium access control for sensor node which is located between physical layer and network layer plays a vital role on the transmission of data.Reasonable MAC protocol can improve the channel utilization and node energy-efficiency and extend wireless sensor network life cycle.Paper first discusses the basic concepts and characteristics of wireless sensor network, highlighting the difference between traditional wireless networks and wireless sensor network, especially many restrictions caused by limited-energy. Then focuses on the classic competition-based MAC protocol-IEEE802.11MAC DCF approach, S-MAC protocol specifically designed for wireless sensor networks, WPAN IEEE802.15.4MAC protocol and protocols based on TDMA scheduling. Paper analyses the problems exposed in these protocols and reaches a conclusion-Wireless sensor network is an application-oriented wireless networks, according to the actual application of the MAC protocol design is reasonable.Finally, paper proposed a polling-based wireless sensor network MAC protocol according to the actual scenarios, which take the control of time-delay and energy-efficiency as a key consideration, however, The new protocol brings new problem that delay of common node’s data transfer is too big, and the paper proposes a clustering mechanism to solve the problem, then conducted a simulation using NS2.