Cluster head node communication. For a clustered communication network, energy consumption of the cluster head node is too fast due to the large data communication traffic. In order to increase the lifetime of the whole clustered network and the balance energy consumption of intra-cluster nodes, we designed a simple random cluster head routing protocol.Table 1 shows the working procedure of the intra-cluster nodes. The cluster head node first sets a cluster head keeping timer, and then receives information from other nodes. When it has received the information, it will firstly determine whether the source node of this information is from this cluster or from the cluster head node of another cluster, and if it is from another cluster, it will forward the information. In order to reduce redundancy of the network information, once it is found that the received packet is from other intra-cluster sensor nodes rather than the cluster head node, it will be immediately dropped. When the cluster head timer overflows,this node will first call the random function and randomly obtain the number of the next cluster head node, then it will broadcast the information of the cluster head rediscovery.When the new cluster head node has received this information, it needs to return the ACK information to the previous cluster head node and broadcast the cluster head reset information to other intra-cluster nodes. If after the previous cluster head has sent the message of cluster head rediscovery it has not received the ACK message after waiting for a while, in order to reduce the complexity of protocol, at this moment, we let the previous cluster head node reset its
cluster head keeping timer and continue being the cluster head node.