Load Balance and User Association on HetNets

Heterogeneous Networks (HetNets) come as a clever approach to increase the capacity and the coverage of cellular networks in which low power base stations can share the load of high power ones. However, it also brought new challenges. For instance, user association strategies used on homogeneous networks are no longer so efficient. In this work, the user association problem is modeled as an integer linear programming (ILP) problem aiming to balance loads among macro and small cells. A greedy heuristic based on it, called LP_GREEDY, is presented. In addition, a distributed one, PROB_MIN_LOAD, is also introduced. These heuristics produce good solutions in terms of number of accepted users and load balancing among base stations in comparison with the optimal solution and with some strategies presented in the literature.