A Lookback Scheduling Framework for Long-Term Quality-of-Service Over   Multiple Cells
  In current cellular networks, schedulers allocate wireless channel resources to users based on instantaneous channel gains and short-term moving averages of user rates and queue lengths. By using only such short-term information, schedulers ignore the users' service history in previous cells and, thus, cannot guarantee long-term Quality of Service (QoS) when users traverse multiple cells with varying load and capacity. In this paper, we propose a new Long-term Lookback Scheduling (LLS) framework, which extends conventional short-term scheduling with long-term QoS information from previously traversed cells. We demonstrate the application of LLS for common channel-aware, as well as channel and queue-aware schedulers. The developed long-term schedulers also provide a controllable trade-off between emphasizing the immediate user QoS or the long-term measures. Our simulation results show high gains in long-term QoS without sacrificing short-term user requirements. Therefore, the proposed scheduling approach improves subscriber satisfaction and increases operational efficiency. 
Hatem Abou-zeid, Hossam S. Hassanein, Stefan Valentin, Mohamed Feteiha
cs.NI