First active 40 Gbps backbone line in Europe: RASCOM introduced advanced Nortel solution for FOCL

Capacity of CJSC RASCOM's own backbone fiber-optic network has substantially increased thanks to usage made of transponders featuring bandwidth of 40 Gbps, its reliability grew higher, too, due to the possibility to transmit traffic over alternative independent routes which, in the long run, has assured maximum efficiency of investments into the network infrastructure being created.
Now, CJSC RASCOM is, already, in possession of two DWDM backbone systems at the route Moscow - Stockholm that had been built usage being made of fibers in the cables passing over different lines, in independent equipment sets. Both DWDM systems make use of Nortel-manufactured CPL equipment and permit to trannsmit, over one fiber pair, up to 72 wavelengths at a bandwidth of 40 Gbps while the total capacity of each system can reach 2.880 Gbps.

An important peculiarity is that it is on Rascom network, for the first time in Europe, transponders with a bandwidth of 40 Gbps have been installed. They permit to increase the capacity of a wavelength by four times from 10 Gbps through 40 Gbps without widening the spectrum of the signal transmitted, that is, no up-grade for linear path is required whose cost might reach 80% of the transmission system cost. So, it is possible to increase the network capacity without placing or purchasing new fibers.
Nowadays, the capacity of the existing networks imposes serious restrictions on the constant ghrowth of the traffic to be transmitted which can lead to remarkable degradation of the quality of the services provided. It is more and more difficult for the operators to handle the video-traffic volume growth: user application get more popular that are intended for watching video through the Internet (Youtube) and Internet TV, high-definition video transmission volumes increase, more and more people communicate over Internet in social networks. In parallel to this, corporate networks' traffic is constantly growing due to growth of business-services spectrum offered and increase of virtual private networks number.
With this situation, the operators try and do their best to increase, to maximum, the primary communications networks bandwidth in order not to let happen quality degradation nor traffic transmission rate decrease.

The Company Nortel was the first in the industry to offer optic technology pertmitting to develop networks with data transmission rate of up to 40 and 100 Gbps per wavelength allowing the operators to meet the permanently growing need in bandwidth.
"Using the Nortel CPL-platform and introducing 40 Gbps standard products will permit Rascom to defend investments into fiber-optic systems and meet permanently growing customers' requirements to the bandwidth.- V.I. Kireev, General Director of Rascom is sure of it;-The fact itself of this innovation stresses that, on the eve of its 15th anniversary, Rascom that was the fuirst to have built an SDH and DWDM fiber-optic network in Russia is not only a successfully developing operator, but rather a leader in the field of introducing new technologies, not only in Russia, but on European scale."
Main advantages of the new Nortel equipment generation can be summarized as the following technical solutions:

• using double polarization and coherent detection quadrature phase modulation that makes it possible to increase total transmission rate at one wavelength up to 40 Gbps without widening signal spectrum over linear paths that had earlier been used for 10 Gbps rate transmission;
• using advanced adaptive techniques of digital signal processing that permit to fully reject analog methods of compensating for signal distortion due to chromatic and polar-mode dispersion. Thanks to this, the distance of sending the digital signals without necessity to regenerate those at use of the CPL equipment reaches 2,000 kilometers which is more than double as compared with the same index of other solutions now at the market.
  
  " Nortel's solution is a must for transportation network operators such as Rascom that use a perspective approach to build next generation networks,"- says E. Lisitsin, Nolrtel Managing Director for Russia, CIS and Baltic countries.-"The issue of significantly extending the bandwith and optimizing the management is one of the most vital for any operator. By leading experts' evaluations, the existing Internet can sink under growing trafficc volumes some years from now if transport route operators do not up-grade their infrastructure in due time. Nortel is offering a very efficient solution to up-grade exisating optic networks that will permit to increase several times the capacity of the existing transport optic routes. A modern network should not only meet current needs of its customers, but foresee possibilities of a flexible and economically efficient approach to permanently growing demand for the bvandwidth."
  It should be noted that all operations to monitor the equipment, optimize linear path parameters, localiuze and eliminate its anomalies, manage the traffic and administer CJSC RASCOM's DWDM network at both Russian and foreign segments are performed from a unique Management Center in Saint-Petersburg. For this purpose, the last version ofthe software program Nortel Optical Network Manager is used that offers exwended opportunities of network planning, organizing and operating a backbone network without practically any technical personnel staff at the network nodes.