Standard quadruples fibre optic transmission capacity and lowers cost
Geneva, 7 November 2003 /The Wi-Fi Technology Forum/- The International Telecommunication Union (ITU) has reached agreement on a new global standard that quadruples capacity of the optical transmission systems which link the nodes of telecommunication networks. The new standard, which allows a transmission speed of 40 Gbit/s, has been developed for carriers to be able to bring down the cost per bit (of data carried) and the costs of network maintenance and management.
The standard — ITU-T Recommendation G.959.1 — increases the capacity for optical interfaces from the present maximum of 10 Gbit/s to 40 Gbit/s. The completed work goes hand-in-hand with other work by ITU in optical transport networks, which encourage a fair market for manufacturers and operators, and ultimately encourages better service for consumers. It is already finding it’s way into optical interfaces developed to exploit the demand for high capacity Internet routers. The standard follows extensive field trials between a number of service providers and manufacturers.
Moving to higher bit-rates will reduce the number of optical systems required in a network. "Historically", says Peter Wery, Chairman of the ITU-T group responsible for the standard, "each fourfold increase in data speed has multiplied costs by just two and half times, leading to lower cost per bit. If this historical precedent holds true, 40 Gbit/s technology will reduce systems equipment costs by up to 40 per cent.
In response to the need for connecting network nodes placed at different distances, the new standard targets two un-amplified link distances: the first is for lengths up to 40 km and the second for up to 80 km.
Only 40 Gbit/s single-channel interfaces are standardized in the present version of ITU-T G.959.1.
The 40 Gbit/s systems covered by ITU-T G.959.1 can be installed on most existing ITU-T G.652, ITU-T G.653 and ITU-T G.655 optical fibres. However, in order to make the deployment of 40 Gbit/s systems still easier, ITU approved in January 2003 a revision of the Recommendations ITU-T G.652 and G.655, in order to include more stringent limits for Polarization Mode Dispersion.
Many new technologies are used in this standard, such as Forward Error Correction (FEC) techniques and adaptive chromatic dispersion compensators.
ITU-T Recommendation G.959.1 (Optical transport network physical layer interfaces) is one of the most recent in the G-series which specifies physical layer attributes of optical interfaces. It provides optical interface specifications for single-channel 40 Gbit/s systems with target distances of 40 km and 80 km. The applications use a C-band wavelength of 1535-1565 nm. The deployment is on single mode fibres as specified in Recommendations ITU-T G.652, G.653 and G.655.
For further information please contact:
Mr Greg Jones
ITU-T Communications Coordinator
Tel: +41 22 730 5515
Email: greg.jones@itu.int
Mr Paolo Rosa, Counsellor
ITU Telecommunication Standardization Bureau
Tel: +41 22 730 5235
Email: paolo.rosa@itu.int
Mr Peter Wery
Chairman Study Group 15
Tel: +1 613 763 7603
Email: wery@nortelnetworks.com
Mr Gastone Bonaventura
Chairman WP 4/15
Tel: +39 335 382905
Email: gastone.bonaventura@telecomitalia.it
About ITU:
ITU is a world-wide organization which brings governments and industry together to coordinate the establishment and operation of global telecommunication networks and services; it is responsible for standardization, coordination and development of international telecommunications including radiocommunications, as well as the harmonization of national policies.
To fulfil its mission, ITU adopts international regulations and treaties governing all terrestrial and space uses of the frequency spectrum as well as the use of all satellite orbits which serve as a framework for national legislations; it develops standards to foster the interconnection of telecommunication systems on a worldwide scale regardless of the type of technology used; it also fosters the development of telecommunications in developing countries.
ITU also organizes worldwide and regional exhibitions and forums bringing together the most influential representatives of government and the telecommunications industry to exchange ideas, knowledge and technology for the benefit of the global community, and in particular the developing world.
http://www.itu.int
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