Improvement And Simulation Research On S-MAC Protocol In Wireless Sensor Network

Wireless sensor network which is integrated wireless communications, sensors, embedded computing and network technology is a typical without infrastructure communications network.WSN is deployed in the test area by the large number of low-cost tiny sensor nodes.It is a multi-hop and organization's network system connected by wireless communication.It will be integrated logical information and objective physical world together. It has changed the way humans interact with nature and has broad application prospects.This paper first introduces the topic background, the wireless sensor network research present situation and the research significance.Next it introduces the wireless sensor network architecture, communication protocol stack and application prospects.Then this paper has enumerated several kind of classical MAC protocols and has carried on the comparison and the analysis to them.Medium Access Control (MAC) protocol determines the radio channel used by way of sensor nodes in the communication between the allocation of limited resources.It has become a wireless sensor network research focus.In this context, this article has analyzed the wireless sensor network communication protocol and the development present situation, then has mainly conducted the following several aspect research:(1)This paper studies and discusses the three types of typical MAC protocols, namely, competitive type, distribution type and mixed type MAC protocol.Then this paper analyzes the wireless sensor network MAC layer which is now facing major technical challenges.(2)S-MAC protocal is discussed in detail of the working mechanism.We sums up the S-MAC protocol performances and design principles.Although S-MAC protocol has many advantages, it uses a fixed duty cycle mechanism.Therefor it does not well adapte dynamic network requirements.This is S-MAC protocol shortcoming.(3)This paper has made the improvement regarding the S-MAC fixed dutycycle mechanism.It proposes dynamic dutycycle plan and optimal dutycycle plan in the network current capacity.We use the network simulator (NS2) to simulate and analy the S-MAC protocol and NEW-SMAC protocol,OD-SMAC protocol.The experiment results show that the NEW-SMAC protocol improves network latency, packet delivery ratio and throughput performance improvements in certain aspects.The OD-SMAC protocol surpasses the S-MAC protocol in the network synthesis performance aspect.