Radio-over-fibre networks: Developments from the BONE Virtual Centre of Excellence in Access

Over the past three years the BONE Network of Excellence has fostered integration and research collaboration between the leading groups in radio-over fibre (RoF) technologies across Europe as part of the Virtual Centre of Excellence in Access. This paper reports on some of the key technologies to emerge and the Centre´s vision of the future. One innovative aspect has been the investigation of radio technologies for intelligent monitoring and management of next-generation access networks; this with a particular aim of introducing energy efficiency techniques and technologies into the access, currently the least energy efficient part of the global telecommunications network. By introducing intelligence (i.e. in addition to basic network cognition functionality), and reconfigurability into next-generation access networking, significant energy savings can be made to reduce the overall carbon footprint of future ultra high-speed internet access - this even despite the predicted exponential increase in future individual access rates (e.g. predicted to reach 1 Gb/s per end-user by 2020). Specifically, as part of the BONE vision for future RF-based access technologies we have undertaken the first experimental demonstration of arrayed-waveguide grating (AWG) cognition using single-mode fibre (SMF)-tailed, C-band vertical-cavity surface-emitting lasers (VCSELs). The basic principles utilise orthogonal frequency division multiplexing (OFDM) signal manipulation, with off-the-shelf components used to demonstrate, for the first time, non-intrusive C-band port alignment in AWG-based access networks. Multi-band (MB)-OFDM tones in the 3.168 to 3.696 GHz band were employed to probe AWG band edges using the intrinsic tunability available from a VCSEL.