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  1. S. Aalto, P. Lassila and P. Osti, Whittle index approach to size-aware scheduling with time-varying channels, in Proceedings of ACM SIGMETRICS, 2015, Portland, Oregon, USA (bib)
    Abstract: We consider the optimal opportunistic scheduling problem for downlink data traffic in a wireless cell with timevarying channels. The scheduler itself operates in a very fast timescale of milliseconds, but the objective function is related to minimizing the holding costs in a much longer timescale. The Whittle index approach is a powerful tool in this context, since it renders the flow-level optimization problem with heterogeneous users tractable. Until now, this approach has been applied to the opportunistic scheduling problem to generate non-anticipating index policies that may depend on the amount of attained service but do not utilize the exact size information. In this paper, we produce a size-aware (i.e., anticipating) index policy by applying the Whittle index approach in a novel way. By a numerical study based on simulations, we demonstrate that the resulting sizeaware index policy systematically improves performance. As a side result, we show that the opportunistic scheduling problem is indexable when the file sizes follow the Pascal distribution, and we derive the corresponding Whittle index, which generalizes earlier results.