Remote functionalities in next generation networks

In the past few years optical networks experienced, as a long wave effect, a substantial increase in the transported bandwidth in all the sectors. From the high speed Transport to the low speed Access up to the End User. At the event horizon, the introduction of mixed fully transparent networks, ring+tree, to cover all the metro-access scenario, open the way to the implementation of extended metro networks from the Core up to the End User. In this scenario, has been experienced a boost in the transmitted bandwidth/data rate, more and more closed to the end user premises, and a massive introduction of passive plants in the access segment to cope with the green challenges and to lower the CAPEXs. The potential deployment of 40G and 100G links, furthermore, implies significant challenges even in well controlled high performance networks (core like). These high-speed signals are naturally more influenced to propagation related impairments (e.g. chromatic and polarization mode dispersion and nonlinearities). Furthermore, in Next Generation Access (NGA) scenarios dominated by long reach passive plants, and in the general context of the global crisis & global warming, becomes important to monitor the physical status of the fiber infrastructures, to push the deployment of green technologies and applications with limited increase in the costs. GPON and GePON standards, for example, fix working wavelengths at 1480 nm (DS) and 1300 nm (US). Different wavelengths are under studies but still have not been implemented yet. Remote transparent devices able to translate standard transmission bandwidths (C-L bands) to standard PON working wavelengths, and vice versa, could become crucial to not increase end-user expenses and to fully open the network to non incumbent operators. Having this capability at the physical layer will surely result in new business models and opportunities, giving the fiber plant runners and deployers the opportunity for exploiting them directly without requiring data from the second layer network users. Centralizing key functionalities like for example amplification and wavelength conversion, or adopting simultaneous remote measurements of impairments such as power, OSNR, CD, PMD and physical infrastructure status on existing networks, becomes a crucial point to speed up the decisions around moving from 10 Gbit/s to 100 Gbit/s deployments. In this paper will be given a general view of the today network scenario with particular emphasis on next generation Metro-Access infrastructures and will be introduced key functionalities and devices in order to perform all optical wavelength processing. Will be presented also the main results of the EU FP7 SARDANA Project, in terms of remote functionalities like amplification, monitoring and signaling.