Scheduling for telemedicine traffic transmission over WLANs

The major disadvantage of the Enhanced Distributed Channel Access (EDCA, the contention-based channel access function of 802.11e) is that it is unable to guarantee priority access to higher priority traffic in the presence of significant traffic loads from low priority users. This problem is enhanced by the continuously growing number of multimedia applications and the popularity of Wireless Local Area Networks (WLANs). Hence, solutions in scheduling multimedia traffic transmissions need to take into account both the Quality of Service (QoS) requirements and the Quality of Experience (QoE) associated with each application, especially those of urgent traffic, like telemedicine, which carries critical information regarding the patients' condition. In this work, we propose an easy-to-implement token-based and self policing-based scheduling scheme combined with a mechanism designed to mitigate congestion. Our approach is shown to guarantee priority access to telemedicine traffic, to satisfy its QoS requirements (delay, packet dropping) and to offer high telemedicine video QoE while preventing bursty video nodes from over-using the medium.