Femtocells present an efficient, low cost solution to help reach the traffic and data rate targets of 5G mobile networks. However, their ad-hoc nature, the expected great density of deployment and their closed registration policy may result in multi-layered networks with base stations' ranges constantly overlapping and non-registered users struggling from the accumulative interference. In this paper, we propose a mechanism where femtocells operate in clusters, and may decide to turn to sleep mode if capacity demand of its users is met adequately by the remaining awake femtocells. We propose a special version of hybrid access targeting only users of neighboring femtocells, in order to reduce the number of active base stations and thus, to reduce interference. We enforce sleep mode under conditions that ensure the increased throughput of each involved registered user and the increased capacity provided by the entire cluster with the extra benefit of reduced energy.
['Christos Bouras', 'Georgios Diles']
Sleep mode performance gains in 5G femtocell clusters