On the optimal assisted rate allocation in N-tier multi-RAT heterogeneous networks

In this paper, we address the emerging 5G heterogeneous networks, which comprise several tiers of small cells of various sizes and by different radio access technologies. As industry has recently been targeting efficient mechanisms for tighter coordination between the tiers of such heterogeneous network, where multiple radios may be utilized simultaneously, we argue that the corresponding problem of assisted resource allocation has not been as widely investigated analytically. To this end, we propose a novel mathematical methodology allowing to deliver the optimal rate distribution for users across the next-generation N-tier wireless network. In particular, we demonstrate that the considered problem of assisted rate allocation can be formulated as a special case of a network flow optimization problem and solved by employing linear programming routines. We also discuss a range of important practical extensions to our baseline model.