On femto-cell deployment strategies for randomly distributed hotspots in cellular networks

We propose user-aware deployment strategies for femto-cell access points (FAPs) in heterogeneous networks where users´ spatial distribution and long-term signal-to-interference plus noise ratios (SINRs) are available to a control centre. Assuming basestations are already deployed, the information on user density and long-term rate coverage is utilized to generate spatial throughput metrics for determining FAP locations. In one approach, regions with the smallest per-user rate coverage are determined as FAP locations where we attempt to find high-user density regions with little coverage from existing infrastructure. In another approach, enhancements from deploying FAPs to candidate locations are predicted based on channel measurements and realistic propagation models. We also investigate step-by-step deployment approaches taking into account the impact of existing FAPs to determine additional FAP locations. Simulations under 3GPP LTE-A heterogeneous network model show that user-aware femto-cell deployment strategies can achieve up to 25% 5-percentile throughput gain, and 80% aggregate throughput gains.