Multi-channel MAC Protocol Design For Wireless Sensor Networks

In recent years,with the development of Internet of Things,Wireless Sensor Networks(WSNs)has been applied lots of different fields,such as target tracking,intrusion detection,conservation of wildlife and so on.A wireless sensor network is composed by hundreds of nodes,and is a distributed system of a collection of information acquisition,processing,and transmission for the integration.Every senor node is relied on battery power and the communication node has more energy consumption than computing node.The media access control(MAC)protocol studies in the paper could effectively avoid many kinds of communication problems,such as interference and conflict of nodes.A well-defined communicating rule plays an essential role in affecting the performance and throughout of the whole networks.Therefore,at present,there are plenty of research on MAC protocols in WSNs.Most of them use time division multiplex access(TDMA)to divide a life time into many slots and adopt the low duty-cycle mechanism,in order to improve the transmission efficiency.However,asynchronous transmission mechanism require a sender has to wait for the receiver waking up to transmit data.It is obviously for extra waiting time.There are also many MAC protocols make use of the multiple channels to transmit data by dividing the channel into many sub-channels.The transmission way of multiple channels could extend the space reusability and reduce communicating conflict.To design a multi-channel protocol is harder than a single-channel protocol,since it needs to overcome many new problems,such as channel allocation and lack of receiver.Exiting multi-channels protocol either has the high hardware cost by reason of the application of multiple receivers.This thesis focused on multi-channels MAC protocols in WSNs.And based on lots of research,we proposed a new MAC protocol,named frequency division multi-channel MAC protocol(FDMCMAC),which makes use of frequency division multiplex access(FDMA)to approve the utilization of channel.This paper is divided into seven chapters.The starting chapter introduces the background,and the value of our research.The second one classifies and analyzes the current MAC protocols.What's more,it compares and analyzes the classical MAC protocols.Since the MAC protocol designed in the paper is based on a clustered network,a clustered algorithm is given in the third chapter.And in the fourth chapter,we gave a detail description for FDMCMAC protocol.The protocol has the following features.(1)Before communicating,nodes will be clustered in order to make data transmission more centralized.The cluster header election algorithm adopted by article,not only uses the node's residual energy as cluster header election of criteria,but also uses the distance between cluster header and the sink node as one of the factors for the cluster header election,which not only makes the cluster header has more energy,but also makes the whole quality of communication can also be guaranteed.Such an elected cluster not only has an energy advantage,but also the whole communication quality can be guaranteed.(2)In the protocol,node communication is divided into two processes.In the inner cluster,cluster member uses multiple sub-channels to transmit data in parallel,for it has fewer data,in general.And the node applies reservation mechanism from bottom to top between the low-level cluster header and the high-level cluster header to transmit data,such that the energy of the higher-level cluster header can be saved.The fifth chapter analyzes the energy consumption of the FDMCMAC protocol theoretically.The sixth chapter compares and analyzes the FDMCMAC protocol and the 802.11 protocol from the aspects of transmission delay and packet success rate.The last chapter summarizes this thesis and figure out the further research on the MAC protocols.