Non-real Time Data Transmission Mechanism with Mobile Sink in Cluster-Based Wireless Sensor Networks

In traditional wireless sensor networks, the sensed data will be forwarded to sink by multi-hop, so that the hot spot problem will happen on the nodes near the sink. The power consumption of these nodes is higher than others, these nodes will be dead sooner. It leads to the network lifetime decreasing. We proposed a data transmission mechanism using mobile sink to solve this problem. We use two threshold values to prevent data overflow. If the data buffer of cluster head exceed to 1st threshold, the node will call sink to come and transmit data. If the sink didn´t arrive the transmission range of the node, and the data buffer exceed to 2nd threshold. Instead of forwarding data to sink directly by multi-hop, we use forwarding data to cluster head of neighboring cluster to help buffer the exceeded data. It can decrease the number of node which has to help to help to forward data, so that it can decrease the power consumption of network, and prolong the network lifetime.