Research On Power Control And Clustering Routing Algorithm For Wireless Sensor Networks

Wireless Sensor Networks (WSNs) is a kind of novel multi-hop wireless network with its characteristics of non-infrastructure, data-centric and self-organized. As an emerging information acquisition technology, WSNs has great potential application prospects, and it soon become the research hot spot both at home and abroad. It also arouse great concern in the field of military, industry, and academia. Compared with the traditional wireless networks, nodes in WSNs have some weaknesses such as energy-limitation, crucial deployment environment, it also have difficuty in energy replacement and supplement, and the life cycle of the network is directly influenced by the energy of the nodes. Thus, the key problem of practical application for WSNs, turns into how to make the full use of the limited nodes' energy to prolong the networks'existence.Target at increasing energy efficiency, network throughput and channel utilization of WSNs, this dissertation tries to use power-control technology, cross-layer optimal design and clustering scheme to exploit cluster-based routing algorithm so as to improve the whole network performance of WSNs. The main research works are as below:â… . It analyses power control technology, cluster-based routing and cross-layer design. On the base of the WSNs'application features, this dissertation first presents the effect of power technique on network performance, states the mechanism and policy of adjustment of power control in WSNs and then discusses the possibility and method of power control mechanism along with the wireless propagation model. Besides, on account of routing characteristics of WSNs, this dissertation analyses clustering layer structure and its clustering strategy, it also discusses the relevance of clustering and power control. Additionally, to deal with WSNs' framework, it analysis the basic idea of the cross-layer optimization design and its related models, then further discusses novel cross layer design model based on discussion of relationship among power control, clustering and cross layer design.â…¡. An energy-heterogeneous-based distributed clustering algorithm is proposed. In view of energy heterogeneous for each node in WSNs, the dissertation proposes an energy heterogeneous distributed clustering (EHDC) for energy heterogeneous environment. Based on local information of cluster and using related evaluation factor of nodes'current energy level, EHDC can adjust the probability of becoming cluster head and the cycle of rotating cluster head during the runtime for a node. This scheme can make the node which has high energy level have more chances to be selected as cluster head. Thus, the network lifetime will be longer for the balance of energy consumption. AEHDC algorithm, an advanced EHDC algorithm is furthermore proposed. The simulations proved that both EHDC and AEHDC have great adaptability and extendibility in energy heterogeneous environment. It greatly improved its energy efficiency, balanced energy consumption, and the network lifetime is significantly prolonged.â…¢. It proposes a distributed and directed clustering routing protocol based on load-balance. Aiming at the load balance problem during network clustering for WSNs, this dissertation supplies an distributed directed clustering algorithm (DDC) based on load balance. In this way, the pre-evaluation factors which are used for pre-evaluating the energy level and load capacity for each node in the next round are presented. During the clustering of each round, the whole network is firstly divided into several appropriate subareas by the energy pre-evaluation factor, then the cluster head of each subarea is selected according to the load balance pre-evaluation factor. The former effectively guarantees network's energy balance in each subarea, the latter brings about load balance in each subarea. This made network energy organically combined with the load of nodes. In this way, it can maximize the network's lifecycle. The simulations prove that DDC algorithm significantly outperforms some similar algorithms in terms of energy efficiency, and the load of each node in WSN is more balanced. DDC shows its great adaptability and extendibility even in energy heterogeneous network environment.â…£. It proposes a stable clustering routing algorithm based on optimal connectivity power. Since there exist some problems in nodes deployment, such as network separation, high density and intense competition in hot spots, this dissertation proposes a stable clustering algorithm based on the optimal connectivity power(SCOC). By using the alterable power control technology and optimal number of neighbors, the algorithm achieves the optimization of transmit power and connectivity. SCOC also brings about assignment for nodes'optimal connectivity power and neighbors'optimal transmit power. Furthermore, in SCOC, optimal connectivity power can effectively decrease congestion range in hot spots, reduces competition intension, and raise the channel utilization ratio as well as network throughput. Moreover, SCOC realized the stable connectivity and clustering of network. Meanwhile the topology of network can also be simplified. In this way, it can maximize the network's lifecycle. The simulation results proved that SCOC has good auto-adapted ability, it can effectively maintains the connectivity and stability of network, and improve the energy efficiency and network throughput. it also has an obvious effect in the promotion of the whole performance of network.â…¤. It states a clustering routing algorithm based on link power control. To deal with link layer energy control in non-uniform network deploy environment, the dissertation proposes a clustering routing algorithm based on link power control (CLPC). Based on optimal connectivity clustering and using dual-channel mechanism with anti-control interference strategy, CLPC solves the problem of collision re-transmission and channel access fairness in network layer, so as to improve the whole network performance. collision and competition intension among nodes can be reduced by optimal connectivity power mechanism, and collision probability during data transmission can be decreased by dual-channel mechanism so as to lead the improvement of channel utilization. Moreover, anti-control interference strategy, by anti-controlling nodes which are high transmit power, can guarantee low transmit power nodes to ensure they can share channel fairly. The simulation results show that CLPC algorithm has a further improvement for energy efficiency and system throughput.