Research On Routing Algorithms And Relevant Issues For WSN

WSN(Wireless Sensor Network), which are composed of many tiny sensor nodes that arecapable of sensing, calculating, storing and wireless communicating, can collect theinformation from the monitoring area and send the information gathered to Sink node by theways of multihop and self-organizing. It involves wireless communication technology,microelectronic technology, sensor technology, embedded computing , distributed informationprocessing and so on. As an new instrument for information gathering and processing, WSNhas great potential in military, civil use and so on, which have drawn the attention of theacademic and industrial circles.However, the energy and wireless communications capacity of sensor nodes are so limitedthat the lifetime of WSN is short, and that QoS is unstable. How to use energy efficiently toprolong the lifetime and enhance the real time of QoS are the key issues of the research onrouting algorithms for WSN. Adopting energy-efficient routing algorithms and appropriatecovering strategy can improve the performance and QoS of WSN. In this dissertation, westudy on the routing algorithms and related issues for WSN, the performance of which isanalyzed and optimized on energy efficiency, delay, coverage and energy balance. The mainwork and contributions of this dissertation include:1. The dissertation introduces WSN and relevant technology broadly and explains themeaning and present condition of the research on WSN. By analysing the architecture,application area, key technology and performance index of WSN, the dissertation revealsthe potential and trend of WSN and interprets the problems and challenges in WSN.2. Routing algorithms in WSN and its evaluation indexes are summarized on topology, QoS,status maintaining and communication mode and the core ideas and performanceattributes of WSN are accounted for deeply. These provide the references for the designand research on routing algorithms in WSN.3. SCTC, Static Chain-cluster Routing Algorithm Based on Transmitting Coordinate forWSN, is proposed. SCTC uses Sink to divide the WSN into clusters and all the nodes inthe same cluster form a static chain cluster using a greedy approach according to thedistance between nodes to decrease the energy consumption on clustering dynamically;Adopting the way that communicating in clusters synchronously decreases the delay time;Rotating collecting layers balances the energy consumption among the sensors in thenetwork. SCTC achieves reduction in energy dissipation and latency, but also makes the energy of the network burn evenly and improves the energy efficiency and lifetime of thenetworks.4. MBC, Random Coverage Model Based on Boundary Curve of WSN is proposed. In thecase of the unequal sleep in classical covering strategy, a new concept, curve covering, isintroduced to create the MBC. Using MBC, the average covering rate and the minimalnumber of the nodes in WSN with given QoS can be worked out easily. MBC reduces thecomputational complexity caused by the unequal sleep and provides a easy-to-usecomputing tool for practical application.5. EEM(Energy Equilibrium Model) and TERA(Topology-based Energy-balanced RoutingAlgorithm for WSN), are proposed. In case of unbalanced energy consumption in WSN,TERA creates two trees, collecting tree and transmitting tree by EEM, to reduce theenergy consumption in communication after analyzing the topology and data transmittingof WSN. TERA improves the balance of energy consumption and prolong the lifetimegreatly, meanwhile, it decreases the delay time in communication.6. CRAC, Concentric Ring Cluster Routing Algorithm Based on Coverage for WSN, isproposed. The algorithm divides the WSN into rings using coordinate of concentric ringby Sink. Meanwhile, it works out the coverage partitions of every ring and the rotationalclusters according to QoS of application requirements. Different rotational clusters'sensor nodes in the same ring can alternate into sleep mode to save energy. Each ringsdecide itself whether to be the sending ring judging by energy equilibrium equation. Thedata gathered is collected to the sending ring after it was transmitted to the path oftransmission in parallel. And then, the data is sent to Sink by LEADER. CRAC reducesboth delay time and energy dissipation greatly, prolongs network lifetime and makes theenergy of the network burn evenly.The conclusions in this dissertation can not only provide the academic references for theresearch on routing algorithms and diversify the contents of research for WSN, but also pushthe development of research on cross-layer design, energy efficiency optimizing and coveringcontrol strategy in WSN.