A Novel Clustering Scheme Based On Nodes With Constant Transmission Power For Wireless Sensor Networks

The sensor nodes of constant transmission power are widely employed in wireless sensor networks(WSNs)because of their simple constructions and low costs.The off-the-shelf researches on WSNs' routing protocols are mainly focused on clustering routing protocols.In these protocols,it is usually assumed that the micro sensor nodes are of adjustable transmission power and able to communicate directly with the base station(BS).However,the communication radius of sensor nodes is limited in practical,which causes isolated cluster heads'(CH)occurring in practical applications.With the help of relay nodes,the state-of-the-art clustering algorithms have solved this problem for the time being,but isolated clusters or black holes will appear on account of early deaths of relay nodes due to much more energy consumption in forwarding packets.In order to avoid generating isolated CHs,we propose Diffusion Clustering Routing Protocol(DCRP),a brand new clustering algorithm,which is based on nodes with fixed transmission power.The full text work is as follows:1.WSN's architectures,key technologies,main features,challenges,and application prospects are researched.WSN's system model and topology,energy dissipation model of wireless communication,network protocol stack structure,neighbor sensing model and the sensor nodes' hardware structure are introduced.2.The features and design requirements of the WSN routing protocols are researched.The main ideas and the implementation process of the typical routing protocols for WSN,including plane routing protocols and clustering routing protocols,are analyzed and summarized.The features of the protocols are summarized.The advantages and disadvantages of the protocols are analyzed and finally their application fields are pointed out.3.The reason for isolated CHs' occurring is analyzed.DCRP,a new clustering algorithm based on nodes with fixed transmission power,is proposed.This algorithm adopts a centralized approach to create clusters and its basic idea is clustering in the manner of diffusing outward centered on BS.All the new CHs are selected from the member nodes of existing clusters so that we can guarantee that there is at least one neighbor CH within the communication range of each CH.The number of neighbor nodes out of cluster,depth and residual energy of a node are taken into consideration in the CH selection strategy which balances the energy dissipation of CHs,improves the energy efficiency and reduces the number of clusters.Thus,the network lifespan is prolonged and the transmission delay is shortened.4.The comparative simulations are made on the platform of MATLAB,which validates the feasibility of DCRP and demonstrates the improvements of DCRP in energy efficiency,energy dissipation balance and transmission delay compared with DEBR and EEUC.Analyses and simulation results show that DCRP assures no isolated CHs generated and extends the lifespan of WSNs by approximately 60% and 16% as well as shortens the transmission delay compared with DEBR and EEUC.