Extending REACT to Support Quality of Service: Algorithms and Implementation, With Screening and Performance Experiments on a Wireless Testbed

REACT is a distributed resource allocation protocol that can be used to negotiate airtime among nodes in a wireless network. In this thesis, REACT is extended to support quality of service (QoS) airtime in an updated version called REACT QoS . Nodes can request the higher airtime class to receive priority in the network. This differentiated service is provided by using the access categories (ACs) provided by 802.11, where one AC represents the best effort (BE) class of airtime and another represents the QoS class. Airtime allocations computed by REACT QoS are realized using an updated tuning algorithm and REACT QoS is updated to allow for QoS airtime along multi-hop paths. Experimentation on the w-iLab.t wireless testbed in an ad-hoc setting shows that these extensions are effective. In a single-hop setting, nodes requesting the higher class of airtime are guaranteed their allocation, with the leftover airtime being divided fairly among the remaining nodes. In the multi-hop scenario, REACT QoS is shown to perform better in each of airtime allocation and delay, jitter, and throughput, when compared to 802.11. Finally, the most influential factors and 2-way interactions are identified through the use of a locating array based screening experiment for delay, jitter, and throughput responses. The screening experiment includes a factor on how the channel is partitioned into data and control traffic, and its effect on the responses is determined.