*3.2.6 Sink mobility*

Sink mobility is one of the energy-efficient technique, where mobility is introduced with sink nodes. The mobile sink nodes collect the data from sensor nodes with single-hop while moving in a specified path and then forward the same to the BS. This scheme reduces the workload of nodes which are placed nearer to the sink nodes and it increases the network lifetime. With the help of sink mobility, so many sparse networks can be connected and communicated which in turn provides scalability of the network. Reliability will be improved because of single-hop communication between the mobile sink and sensor nodes. However, trajectory path maintenance is a critical part of sink node while moving. Mobile collector needs a proper synchronization mechanism with sensor nodes, otherwise this causes packet loss while data gathering.
