Data gathering in wireless sensor networks with ferry nodes

Mobile ferries are an alternative way for collecting data from dispersed sensor nodes especially in large-scale networks. Unlike data collection via multi-hop forwarding among the nodes, ferries travel across the sensing field and collect data from the sensing nodes. The advantage of using a ferry based approach is that, it eliminates the need for multi-hop forwarding of data, and as a result energy consumption at the nodes is significantly reduced. However, this increases data delivery latency and as such might not be suitable for all applications. In this paper we survey the recent progress of using mobile ferry nodes for data gathering in WSNs addressing two main areas, determining the path of the ferry and the scheduling when to dispatch the ferry to collect data from sensors. We also highlight challenges facing the deployment of mobile ferries in wireless sensor networks.