Wireless Sensor Network Laboratory

Scheduling Multi-channel and Multi-timeslot in Time Constrained Wireless Sensor Networks via Simulated Annealing (SA) and Particle Swarm Optimization (PSO)

Timely communication in wireless multi-hop sensor networks requires high throughput and low delay, which can be achieved by exploiting multiple channels and timeslots. Efficient scheduling becomes indispensable if multiple channels and timeslots are utilized. Optimum scheduling of multiple channels and timeslots in multi-hop networks is an NP-complete problem. We apply the metaheuristic approaches to solve the scheduling problem because of the fact that not only the global solution but near-optimal solutions can satisfy a given end-to-end delay bound. We adopt the Simulated Annealing (SA) and the Particle Swarm Optimization (PSO) to schedule the resources. Different measures and stopping conditions are explored to validate the feasibility of scheduling via SA and PSO, and to compare the performances of the two metaheuristics in satisfying the desired end-to-end delay.  

Multi-channel MAC for Industrial Wireless Sensor Networks

We study one of the new MAC protocols in IEEE 802.15.4e standard, called DSME (Deterministic and Synchronous Multichannel Extension) mode. DSME enhances the existing IEEE 802.15.4 GTS (Guaranteed Time Slot) to provide robust and timely data delivery for industrial wireless mesh sensor networks. DSME provides two channel diversity techniques, namely channel hopping and channel adaptation, to cope with dynamic channel conditions. Through simulations, we evaluate the performance of DSME and determine the optimal configuration for DSME parameters. Performance comparison of the two channel diversity techniques is also presented.