Admission Control and Scheduling of Isochronous Traffic With Guard Time in IEEE 802.11ad MAC

An upsurge of low latency and bandwidth hungry applications such as virtual reality, augmented reality and availability of unlicensed spectrum in the millimeter wave band at 60 GHz have led to standardization of the new generation WiFi systems such as IEEE 802.11ad and 802.11ay. Due to the stringent Quality of Service requirement of those applications, IEEE 802.11ad/ay have introduced contention free channel access called
Service Period
. One type of user traffic supported by IEEE 802.11ad is isochronous traffic, which is essentially periodic traffic that requires certain channel time to be allocated before its period ends. In an earlier work, we presented three Admission Control Algorithms (ACAs) which admit isochronous requests to achieve the above goals. One of these ACAs, the proportional fair allocation admission control (PFAAC), offers the best tradeoff across different performance metrics. But it did not consider guard time (GT) overhead, which is essential in a practical system. In this paper, we present two methods to compute upper bounds on GT overhead. We evaluate performance of the modified PFAAC with the two methods and PFAAC with no GT overhead. The modified PFAAC with the method that uses a tighter upper bound on GT overhead, provides the best performance.