Tier-based scalable and secure routing for wireless sensor networks with mobile sinks

Multiple hop based routing in homogeneous sensor networks with a single sink suffers performance degradation and severe security threats with the increase of the size of sensor networks. Large-scale sensor networks need to be deployed with multiple powerful nodes as sinks and they should be scheduled to move to different places during the lifetime of the networks. Existing routing mechanisms lack of such supports for large-scale sensor networks. In this paper, we propose a heterogeneous network model where multiple mesh nodes are deployed in a sensor network, and sensed data are collected through two tiers: firstly from a source sensor node to the closest mesh node in a multiple-hop fashion (called sensor routing), and then from the mesh node to the base station through long-distance mesh routing (called mesh routing). Based on this network model, we propose an energy-efficient and secure protocol for the sensor routing that can work well in large-scale sensor networks and resist most of attacks. Experiments demonstrate that our routing protocol significantly reduces average hops for data transmission. Our lightweight security mechanism enables the routing protocol to defend most attacks against sensor networks.