Adaptive Distributed Fair Scheduling and Its Implementation in Wireless Sensor Networks

Maciej Jan Zawodniok, Missouri University of Science and Technology
Jagannathan Sarangapani, Missouri University of Science and Technology
Steve Eugene Watkins, Missouri University of Science and Technology
James W. Fonda, Missouri University of Science and Technology

This document has been relocated to

There were 10 downloads as of 28 Jun 2016.


A novel adaptive and distributed fair scheduling (ADFS) scheme for wireless sensor networks is shown through hardware implementation. In contrast to simulation, hardware evaluation provides valuable feedback to protocol and hardware development process. The proposed protocol focuses on quality-of-service (QoS) issues to address flow prioritization. Thus, when nodes access a shared channel, the proposed ADFS allocates the channel bandwidth proportionally to the weight, or priority, of the packet flows. Moreover, ADFS allows for dynamic allocation of network resources with little added overhead. Weights are initially assigned using user specified QoS criteria. These weights are subsequently updated as a function of delay, enqueued packets, flow arrival rate, and the previous packet weight. The back-off interval is also altered using the weight update equation. The weight update and the back-off interval selection ensure that global fairness is attained even with variable service rates. The algorithm is implemented using UMR/SLU motes for an industrial monitoring application. Results the hardware implementation demonstrates improved performance in terms of fairness index, flow rate, and delay.