Demin Gao

Data Aggregation Routing for Rechargeable Wireless Sensor Networks in Forest Monitoring

In rechargeable wireless sensor networks (r-WSNs), higher data transmitted efficiency is required because sensor have to operate in a very low duty cycle owing to sporadic availability of energy. In r-WSNs, Data collected by many sensors is based on common phenomena, and hence there is a high probability that this data has some redundancy. In this work, we address the problem of jointly optimizing data aggregation and routing so that the network workload can be maximized. Establish the relationship model between data aggregation rate and throughput, so that the balanced was set up between the data aggregation rate and maximum network data traffic. Through the use of optimal candidate sample allocation, the algorithm can coverage efficiently and can make the maximum data aggregation rate flow to the network while maximizing network workload. Simulations are carried out to show that the proposed algorithm can significantly improve workload.

Anycast Routing Protocol for Forest Monitoring in Rechargeable Wireless Sensor Networks

In rechargeable wireless sensor networks (R-WSNs), sensors have to adjust their duty cycles continuously owing to sporadic availability of energy and operate in a very low duty cycle because of current energy conversion technical limitations. Even though the network lifetime is not the main problem, packet delivery latency is critical because a sensor is in the dormant state most of the time in R-WSNs. These unique characteristics pose a new challenge for routing protocol design over traditional energy-static sensor networks. In this work, we introduce a routing protocol based on anycast communications technology, a novel design to minimize packet delivery latency for forest monitoring in R-WSNs. The key idea is to let a sender choose a closest neighbor to forward packets from forwarding candidates and a nearest sink node to accept the packet from all sinks. For multiple source nodes, we introduce an anycast technology based on Tabu search for each source establishing a minimal E2E delay routing path to reach anyone sinks. Through extensive simulation and experiments, we demonstrate that our anycast scheme based on Tabu search is efficient to provide smallest packets delivery latency in R-WSNs.

Delay Bounded Maintenance Scheme in Rechargeable Wireless Sensor Networks

In rechargeable wireless sensor networks, owing to the current energy conversion technology limitations, the energy harvested from surrounding environment usually is not enough to continually power sensor nodes. Therefore, the nodes have to operate in a very low duty cycle, which means nodes have to activate shortly and stay in the sleep state most of the time in order to recharge the energy. On the other hand, due to sporadic availability of energy, nodes must adjust their duty cycles continuously. Hence, packet delivery latency is critical in rechargeable WSNs. In this work, we introduce an active instance augmented scheme and provide an algorithm for finding the minimal sleep latency from a node to the sink by augmenting minimal h active instances. For bounding E2E delay from source node to the sink in the network, we propose an E2E delay maintenance solution. Through extensive simulation and experiments, we demonstrate our delay bound maintenance scheme is efficient to provide E2E delay guarantees in rechargeable wireless sensor networks.