Traffic offloading from LTE-U to WiFi: A multi-objective optimization approach

Traffic offloading and Long Term Evaluation Unlicensed (LTE-U) are two significant techniques proposed to cope with the ongoing heavy burden of cellular wireless networks. Though many works has focused on developing coexistence mechanisms for WiFi and LTE-U on the unlicensed bands, much less have paid the attention to offload traffic from LTE-U to WiFi. In this paper, we consider the maximization of per-user throughput of LTE-U and minimum throughput of WiFi networks simultaneously when offloading users from LTU-U to multiple WiFi networks under WiFi delay constraint. Since the optimization objectives are conflicting, we propose to solve the multi-objective optimization problem based on the e-constraint method in two steps, and we give some analysis on the maximum and minimum throughput of LTE-U users and WiFi users under the multi-objective optimization framework. Simulations demonstrate that the proposed algorithm can achieve the Pareto optimal solution and help achieve the fairness when offloading traffic from LTE-U to multiple WiFi networks.

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