Knapsack Optimisation Versus Cell Range Expansion for Mobility Load Balancing in Dense Small Cells

We present a new approach for mobility load balancing (MLB) and user association in dense small cell scenarios. This Self Organizing Network (SON) approach relies on Knapsack Optimisation (KO) to evenly distribute users across a cluster of small cells subject to constraints. It is shown that the new technique referred to as (MLB-KO) achieves substantial improvements (better than four times reduction) in blocking ratios compared to the case when no MLB strategy is deployed. Comparisons with other approaches relying on Cell Range Expansion (CRE) and Almost Blank Subframes (ABS) are also presented highlighting the effectiveness of the new approach as a centralised self optimisation technique for future dense small cell network deployments.