WSNs have been deployed in a variety of data intensive applications including micro-climate and habitat monitoring, precision agriculture, and audio/video surveillance. A moderate-size WSN can gather up to 1 Gb/year from a biological habitat . Due to the limited storage capacity of sensor nodes, most data must be transmitted to the base station for archiving and analysis. three different approaches, mobile base stations, data mules, and mobile relays, that use mobility to reduce energy consumption in wireless sensor networks. A mobile base station moves around the network and collects data from the nodes. All nodes are always performing multiple hop transmissions to the base station, and the goal is to rotate which nodes are close to the base station in order to balance the transmission load sensor nodes must operate on limited power supplies such as batteries or small solar panels. A key challenge faced by data-intensive WSNs is to minimize the energy consumption of sensor nodes so that all the data generated within the lifetime of the application can be transmitted to the base station. Three different approaches, mobile base stations, data mules, and mobile relays, that use mobility to reduce energy consumption in wireless sensor networks. A mobile base station moves around the network and collects data from the nodes. All nodes are always performing multiple hop transmissions to the base station, and the goal is to rotate which nodes are close to the base station in order to balance the transmission load. Nodes only transmit to the base station Several different approaches have been proposed to significantly reduce the energy cost of WSNs by using the mobility of nodes. A robotic unit may move around the network and collect data from static nodes through one-hop or multi-hop transmissions. The mobile node may serve as the base station or a “data mule” that transports data between static nodes and the base station. Mobile nodes may also be used as relays that forward data from source nodes to the base station.