Cost and energy efficient multi-standard OFDM integrated optical access and in-building network architecture

A cost and energy-efficient OFDM-based network architecture capable of supporting a large number of users in an optical access network integrating the in-building optical infrastructure is proposed. Efficiency is based on the use of flexible optical comb sources and the distribution of multi-standard OFDM-based signals. High capacity is achieved implementing an “elastic” optical comb. This comb is based on time-domain multi-level phase modulation of a pulsed laser. Two-fold and four-fold comb line multiplication is demonstrated employing electro-optic bi-phase modulation. Cost efficiency is further achieved by the transmission of full-standard OFDM-based radio-over-fibre signals in each of the comb wavelengths. This permits a straightforward integrated network including off-the-shelf equipment employing wireless standard signals LTE, WiMAX and UWB, altogether a custom OFDM-GbE signal for wired data. Successful transmission of this OFDM-bundle in coexistence requires mitigation of the optical transmission impairments when a long-reach access network is considered. Using novel impairment compensation techniques enables 100 km standard single-mode fibre reach without in-line optical dispersion compensation in the network. Finally, energy efficiency is addressed integrating broadcast DVB-T transmission in the in-building optical network. In this approach, neither coax cabling nor associated amplification elements are required. Distribution of DVB-T in distances up to 500 m in bend-insensitive single-mode fibre is reported with great flexibility.