Self-organizing Networks for 5G: Directional Cell Search in mmW Networks

We discuss the motivation and potential use-cases of self-organizing networks (SON) in 5G networks. Disruptive technologies and features of 5G networks include millimeter wave (mmW), massive multiple-input multiple output (MIMO), and cloud-radio access network (C-RAN). These have ramifications on SON aspects of the networks. We discuss several new SON use-cases and problems pertinent to emerging 5G technologies. The discussed 5G SON use-cases include spectrum management and sharing, user association, multi-radio access technology (RAT) optimization, and directional cell search for mmW networks. We then investigate directional cell search in detail, and consider a network graph based approach for self-organized beam assignment in mmW 5G networks. Simulations results in a realistic Manhattan environment demonstrate the benefits of proposed approach, in terms of improved user signal-to-interference plus noise ratios to potential handover beams, thereby resulting in better directional cell discovery.