Abstract: In order to solve the problem of energy hole and energy minimization in ring shaped WSNs ( Wireless
Sensor Networks) ，a FCＲA ( Fuzzy logic control based Clustering Ｒouting Algorithm) is proposed． Firstly，the
network is divided into rings with equal width，and the optimal cluster number of each ring is calculated with the
objective function for minimizing the energy consumption of each ring． Secondly，a fuzzy controller is designed to
elect the cluster heads． The input of the fuzzy controller is the residual energy of the node and the distance from
the node to the base station，the output is the probability that the node becomes the cluster head． Finally，the
inter-cluster multi-hop mode is used for data transmission． The weight function of each transmission path is
determined based on the residual energy of the node，the distance of the next hop and the number of hops to the
base station，and the optimal next hop relay node is obtained． The simulation results show that FCＲA can
effectively reduce the network energy consumption and prolong the network lifetime．

Key words: ring shaped wireless sensor networks ( WSNs) , fuzzy logic control, the optimal cluster number, multi-hop routing