Realtime traffic scheduling for missed deadlines minimization in point-to-multipoint OFDMA systems

This paper considers the problem of scheduling realtime traffic in OFDMA systems. We present two heuristics with the objective of meeting as much deadlines as possible, or equivalently, minimizing the number of missed deadlines. The proposed heuristics decide on the allocation priority, taking into account several known parameters about the users and their service requests, such as the available carriers data rates for each user, the traffic amount and deadlines requirements of each service request. These available parameters are combined together by our heuristics for deciding a priority order by which to schedule the service requests. Specifically, we compare two realtime traffic allocation mechanisms: "per-time slot" scheme and "per-deadline" one. We evaluate our proposed heuristics performance, by means of simulations, computing the deadlines miss ratio (DMR), the percentage of users which miss more than 5% of deadlines (UMR) and the maximum missed deadlines percentage for the user who missed most (MMD).