Hierarchical Wireless and Optical Access Networking: Convergence and Energy Efficiency

Node consolidation and an all-passive (PON) infrastructure are important aspects to next-generation optical access (NGOA) networking. Wireless access is another important trend (WiFi, LTE/4G etc.) but requires active outside plant (base-stations). Once electrically-powered (e. g. via renewable energy) outside plant becomes a feature of an integrated NGOA architecture, the question of whether the NGOA network can be adapted and optimised still further (e. g. location of cognitive radio intelligence, vertical handover, locality, caching/content storage etc.) needs to be explored, as well as the additional energy-efficiency savings available with respect to optimising green radio technologies versus low-energy photonics. In this paper, we discuss the issues involved in the optimised design of a hierarchical and converged fixed-wireless access network, focussing on the handover possibilities associated with heterogeneous wireless technologies and the impact on the optimised design of an underlying fixed optical access infrastructure.