QoS Routing Algorithm Of Wireless Sensor Networks

The rapid development of wireless sensor networks(WSNs) and the diversity andcomplexity of applications make traditional network mechanisms based on single servicecan’t meet the requirements of current business operations. The variability of businessoperations require higher demand for types of QoS(quality of service), for instance, nonreal-time application environment requires high energy efficiency and high reliabletransfer, and real-time business demands the consideration of delay and high real-timetransfer. Therefore, how to provide with QoS guarantee routing mechanism for WSNswith limited resources is a hotspot and difficulty in WSNs research.On the basis of the characteristics of the WSNs, this thesis makes a comparison onmerits and weaknesses of existing protocols, and then analyzes the necessity of studyingQoS routing protocols. Finally, this thesis presents two kinds of QoS routing protocols:Delay-Energy tradeoff with reliable communication(DETR) protocol and Balance Energyefficiency and Real-time with Reliable Communication(BERR) protocol. Makingcompromise is adopted to realize balancing among energy efficiency, real-time andreliability when transmitting data.First, this paper analyzes the questions what the WSNs QoS protocols have beenfacing and QoS metrics standards, then makes a discussion on the aspects of the selectionmethods of QoS parameters and QoS design strategy in routing algorithm. And then itanalyzes and compares the advantages and disadvantages, as well as suitable scope of theexisting QoS routing protocols. And on that basis, the main research contents of QoSrouting are proposed: energy efficiency, real-time and reliability, and making a theoreticalprinciple for latter study.Then, the proposed DETR routing protocol establishes the relation between energyand transmission rate with a compromise factor, and then selects the neighbor node withthe better combination property as the relay node. Reliability is as the weight factor and nopacket loss strategy is used to meet the reliability requirement. The simulationexperiments verify DETR algorithm can balance energy distribution and prolong the network lifetime more effectively than traditional SPEED algorithm.Finally, the proposed BERR routing protocol establishes the relation between energyand real-time with a compromise factor, and it makes a further consideration on two hopnodes’energy, which achieves real-time requirements with hop counts, and realizesreliable transmission by retransmission mechanism. At the same time, M-BERR algorithmis proposed by introducing maintaining path mechanism which can avoid uncertainty andhigh routing spending brought by frequent switching path. The simulation results indicatethat BERR has a better performance on energy efficiency, real-time and reliability.