KISTA, Sweden -- Swedish Research company Acreo and leading telecom vendor Ericsson have completed a field trial, running 112 Gbit/s on a single wavelength over an 824 km installed fiber route, provided by Skanova, between Kista and Hudiksvall in Sweden. The trial demonstrated a novel solution based on electronic sub-carrier multiplexing combined with 16-QAM modulation and coherent detection, developed by Ericsson and Acreo in joint research projects directed towards increasing capacity of optical networks.

A 100G upgrade scenario was tested by connecting the dual-polarization 112 Gbit/s wavelength to an existing 10G engineered DWDM system, operated by Acreo, without touching any of the optical amplifiers or dispersion compensation modules. The fiber link connects Kista to Hudiksvall where the fiber was looped back for a total of 12 spans.

The tests involved broad-band radio technology to modulate and demodulate electronic sub-carriers, which allows operation at low symbol rates compared to single-carrier solutions, simplifying A/D-converters and digital signal processing (DSP). Two sub-carriers were modulated onto each orthogonal polarization of a single transmitter laser and detected using a single local oscillator laser in the coherent receiver. By leveraging on electronics integration the number and complexity of optical components can be reduced, thereby saving cost.

Acreo AB