Non-Geographical Shortest Path Data Dissemination for Mobile Sinks in Wireless Sensor Networks

In wireless sensor networks (WSNs), the studies that support sink mobility without location information of sensor nodes traditionally establish a cluster-based virtual infrastructure. The cluster-based infrastructure consists of clusters involving sensor nodes and a shared tree organized by the cluster heads. In the studies, data dissemination from a source node to a mobile sink is performed via the shared tree. The mobile sink makes connection from the current standing cluster into the root of the shared tree; the source transmits data to the root; and the root delivers the data to the mobile sink. Namely, the data from a source may always be detoured to a mobile sink via the shared tree. According to a change of the current standing cluster, the mobile sink could frequently remake connection into the root; thus, excessive energy consumption by the detour problem might seriously happen. In this paper, we propose a communication protocol that provides the shortest path from a source to a sink by exchanging a routing table between neighboring cluster heads. The routing table contains the cluster ID of a neighbor cluster and hop-count from the neighbor cluster to the other clusters. A sink registers the cluster ID of the current standing cluster into the root of the shared tree, and a source then obtains the cluster ID. Thus, the source can deliver data directly to the current standing cluster of the mobile sink. Simulation results show that the proposed protocol is superior to the existing protocol.