The Modified Proportional Fair Scheduler

Until recently, wireless networks had been struggling against fading effects. However, 3G wireless networks have learned to profit from radio channel variations to augment their capacity while serving data traffic. Opportunistic schedulers take advantage from the delay-tolerance of these applications to ensure that transmission occurs when radio channel conditions are most favourable. A well-known opportunistic scheduler that strikes a good balance between fairness and efficiency, in an idealistic environment, is the "proportional fair" (PF) scheduler. Nevertheless, the hypotheses according to which its good performances are obtained are not valid in real environments. In this paper, we propose a modified version of PF that allows for a fair allocation of resources in realistic environments and introduces flexibility in sharing these resources between active users