The cluster head is selected by the random number

generated by nodes in the hierarchical routing protocol which

is implementing Low Energy Adaptive Clustering Hierarchy

(LEACH). As a result, the cluster head may be chosen

randomly and be distributed asymmetrically. Focus on this

problem, this paper introduces a function to improve the

problem. This function uses the relative distance between

nodes and base station and the round number as its

parameters. Hence, the distribution of cluster head can be

symmetrical through changing parameters of the function,

and. With the increasing of running time, every node in the

network has the chance to be a cluster head, that is, the energy

consumption could be balance. The simulation result shows

that the lifetime of Wireless Sensor Network (WSN) has been

prolonged about 14 .

-The cluster head is selected by the random number

generated by nodes in the hierarchical routing protocol which

is implementing Low Energy Adaptive Clustering Hierarchy

(LEACH). As a result, the cluster head may be chosen

randomly and be distributed asymmetrically. Focus on this

problem, this paper introduces a function to improve the

problem. This function uses the relative distance between

nodes and base station and the round number as its

parameters. Hence, the distribution of cluster head can be

symmetrical through changing　parameters of the function,

and. With the increasing of running time, every node in the

network has the chance to be a cluster head, that is, the energy

consumption could be balance. The simulation result shows

that the lifetime of Wireless Sensor Network (WSN) has been

prolonged about 14　.