Deployment aspects of 3G femtocells

In this paper we consider the co-existence of 3G macro and femto base stations (MNB and HNB) on the same frequency carrier. Both restricted closed subscriber group (CSG) and non-CSG HNBs are investigated into. We consider both residential and office/apartment deployments using the agreed 3GPP simulation assumptions. We demonstrate the macro offload capability of HNBs and show that end-user experience in many cases is mainly improved due to being the only one served by the cell. We find that 25% of users would experience worse channel quality towards their HNB than towards the MNB in the same location, though the overall network capacity is improved. Results indicate that an operator should take some care as to where HNBs are deployed and have at least a single CSG-HNB free carrier to ensure wide area coverage inside buildings (even if aggressive power control schemes are used).