You are here: Home / Research / New Research: CRITICAL

New Research: CRITICAL

Component Requirements and Integrated Transceiver Investigation for Coherent Access Links

We are pleased to announce CRITICAL, a new EU project in the Optical Networks Group, led by Dr Seb Savory.

Today's fibre to the home solutions offer up to a few 100 Mbit/s data rate and passive optical network systems with an uncontended symmetrical rate of 1 Gbit/s are currently under development. This project aims at the following generation: delivering uncontended symmetric data rates of up to 10Gbit/s by exploiting the developments which have occurred in the core network, such as digital coherent receivers and advanced modulation formats. Coherent access technologies address the requirements of next generation access networks through a symbiotic combination of spectrally efficient modulation, coherent detection and digital signal processing (DSP):

  • Coherent detection maximises efficacy of DSP and permits use of spectrally efficient modulation, allowing a high channel density. This provides for a dedicated wavelength per subscriber, with high split ratios and uncontended bandwidth.
  • Coherent detection provides higher sensitivity to received signals which, combined with forward error correction, allows for longer reach and higher split ratios.
  • DSP simplifies the receiver, removing need for optical phase and polarisation tracking. It compensates for transmission impairments, increasing the obtainable transmission length.

The objective of the project is to specify, design, build and test a technology demonstrator of the proposed system, including photonic and electronic integrated circuits, DSP and transceiver integration, using the expertise of the project partners, Oclaro, Deutsche Telekom, National Physical Laboratory, Nokia Siemens Networks, PMC Sierra and University College London. This will allow both the practicality of the proposed solution to be established and the techno-economic issues associated with relaxing the component specification to be investigated experimentally.