|International Telecommunication Union
For immediate release
|Telephone: +41 22 730 6039
Fax: +41 22 730 5939
Standard quadruples fibre optic transmission
capacity and lowers cost
ITU meets industry demand for next generation networks
Geneva, 7 November 2003 — 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.
Note to technical editors:
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
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: