Optical fiber is the required technology for Radio Access Network (RAN) backhaul and fronthaul. We report the evolution of RAN equipment including the advent of virtualization and an investigation of the required architecture and optical access technologies.

A real-time transmission of a new functional split fronthaul interface over PtP and PtMP optical access networks is experimentally demonstrated. The data traffic evolution is investigated as well as the impact of latency and packet loss.

International audienceWe report on a simple and fast method to estimate the fiber dispersion and laser chirp parameters on a dispersive Intensity Modulation and Direct Detection (IM/DD) optical channel. Based on the general IM/DD small-signal frequency response, we use the Downhill-Simplex algorithm to fit the channel measurement retrieved with a network analyzer to a general mathematical model. The method is proven to be quite efficient for light sources of different natures and with different adiabatic and transient chirp characteristics, including a Distributed Feedback (DFB) laser, an Electroabsorption modulator (EAM) and even a Reflective Semiconductor Optical Amplifier with fiber-Bragg grating (RSOA-FBG)

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International audienceFiber dispersion coupled with chirp parameter of the emitting laser impacts the optical transmission system performance. Fiber dispersion causes the propagating pulses to spread and overlap, and the chirp parameter produces a wavelength shift arising from the intensity variation of the directly modulated laser (DML). For optical transmission systems, orthogonal frequency division multiplexing (OFDM) modulation technique has proved to be an attractive approach to overcome optical fiber impairments in optical access networks as well as in long haul optical networks. Coupled with the Levin Campello bit-loading algorithm, adaptively modulated optical orthogonal frequency division multiplexing (AMOOFDM) optimizes the data rate by taking into consideration the channel quality of each subcarrier. This paper shows system performance for optical links starting with an optical back-to-back (BtB) connection and ending with 125 km of single mode fiber (SMF) with a fixed optical budget of 30 dB for all distances

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