Research On Communication Protocols And Localization Algorithm Of Wireless Sensor Networks

With the rapid development of Micro Electro-Mechanical System(MEMS) technologies,embedded computing technologies,communication and sensing technologies,Wireless Sensor Networks(WSN)have become the key technology in the new era of sensing technologies.WSN consist of low-cost, low-power tiny sensor nodes that can communicate with each other to perform sensing,computing and communicating.Based on the diverse onboard sensors,WSN can sense the field and transmit the information to the remote sink in an efficient and timely manner.The sensing performance and reliability have been improved significantly in WSN.So they have a wide range of applications in national defense,military,national security,environmental monitoring,traffic surveillance,medical treatment,manufacturing industry and even anti-terrorism,etc.This dissertation mainly focuses on important problems of network communication protocols and localization algorithm.The main contribution of this thesis is summarized as follows;(1)The first part of our work is concerned with Data Link Layer in Communication Protocol Stack of WSN.Medium Access Control is main function in Data Link Layer.We first analyze the existing MAC protocols for WSN and Ad-hoc Networks and further propose a simple and effective Multi-Channel MAC protocol(MCMAC)for WSN,which is based on multi-channel transceivers.The simulation results show that the protocol improves throughput and energy efficiency,at the same time,prolongs the network lifetime.(2)The second part of our work focuses on the routing protocols in WSN. We find that WSN have to support many kinds of applications,some of which may be non real-time applications while others have strict real-time data transmission requirements.Thus,it is necessary to design routing protocol that can provide different real-time data transmission services for the various applications.On the other hand,energy consumption is one of the important criterias for WSN,We proposes a novel adaptive real-time routing protocol(ARTRP),which provides different real-time levels for diverse applications and improves the energy efficiency. Analysis and simulations are conducted to evaluate this protocol.The results show that the performance of the proposed protocol is better than the peer.(3)The third part of our work mainly is involved with the localization algorithm of WSN.In WSN,the position information of sensor nodes is a requisite for various purposes.The data collected from the sensor nodes makes sense only when it is accompanied with its position information. The data without position information is almost not fit to carry guts to a bear.Furthermore,the communication protocol,scheduling management algorithm and the topology algorithm of WSN,all need the position information.Therefore,the localization technology provides an important technical support for WSN.Based on the existing localization algorithms of WSN,this paper proposed an active distributed localization algorithm(ADLA)for sensor node,on the basis of convex programming approach,which offers a kind of simple distributed approach to estimate the position.Through simulation,it is proved that the precision of localization can meet the general localization requirement of WSN.(4)Ship Engine Room Monitoring & Alarm System is a important part of automation system on board,its main functions is to monitor the state and parameters of the equipments.The reliability of the Ship Engine Room Monitoring & Alarm System directly affects the ship navigational safety. The existing Ship Engine Room Monitoring & Alarm System can be divided into four types----conventional system,centralized system,distributed system and FieldBus-based system.These types of systems require laying a large number of communication cable.Harsh environment in the engine room makes these communication cable easy damaged.They need a lot of repair and maintenance work.The last part of our work proposes a WSN-based Ship Engine Room Monitoring & Alarm System and sets up a prototype of system.This system reduces failure rate and improves the reliabilityCurrently,WSN encounter many problems.The energy problem is especially serious.How to design suitable protocols according to its features is very important for its development.