Mobile nodes path design and deployment for data collection in wireless sensor networks
Tian Wang · 2011
Recent years have seen the deployments of wireless sensor networks (WSNs) in data-intensive applications. WSNs in these applications often produce high-bandwidth sensor data that need to be collected under stringent delay constraints. On the other hand, sensors in such applications must operate on limited power supplies like batteries for extended lifetime up to years. Therefore, a fundamental challenge for these WSNs is to support Time-sensitive data collection with minimum network energy consumption. Motivated by these factors, we introduce mobile nodes (MNs) for collecting high-bandwidth data which can greatly save the energy of sensor nodes since the energy consumption of mobile nodes is less constrained as they can replenish their energy supplies because of the mobility. The major work of this thesis can be summarized as follows. First, we introduce mobile elements (MEs) to collect data to the base station (BS). A subset of nodes serve as the rendezvous points (RPs) that buffer data originated from sources and transfer to MEs when they arrive, which can achieve a desirable balance between network energy saving and data collection delay. We prove that the optimal schedule problem is NP-hard and develop two rendezvous planning algorithms: RP-CP and RP-UG. RP-CP finds the optimal RPs when MEs move along the data routing tree, while RP-UG greedily chooses the RPs with maximum energy saving to travel distance ratios. Our approach is validated through extensive simulations. Second, some urgent data may need to be sent to the BS through a routing tree before the arriving of MEs, but the nodes on this tree may consume much more energy, which is a bottleneck for the whole network. Our solution is to make some