Motivated by the rapid development of energy harvesting technology andcontent-aware communication in access networks, this paper considers the pushmechanism design in small-cell base stations (SBSs) powered by renewableenergy. A user request can be satisfied by either push or unicast from the SBS.If the SBS cannot handle the request, the user is blocked by the SBS and isserved by the macro-cell BS (MBS) instead, which typically consumes moreenergy. We aim to minimize the ratio of user requests blocked by the SBS. Withfinite battery capacity, Markov decision process based problem is formulated,and the optimal policy is found by dynamic programming (DP). Twothreshold-based policies are proposed: the push-only threshold-based (POTB)policy and the energy-efficient threshold-based (EETB) policy, and theclosed-form blocking probabilities with infinite battery capacity are derived.Numerical results show that the proposed policies outperform the conventionalnon-push policy if the content popularity changes slowly or the content requestgenerating rate is high, and can achieve the performance of the greedy optimalthreshold-based (GOTB) policy. In addition, the performance gap between thethreshold-based policies and the DP optimal policy is small when the energyarrival rate is low or the request generating rate is high.
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