Alcatel Claims DWDM Distance Record

Alcatel (NYSE: ALA), the world leader in optical networking, today announced it has set two world records for Dense Wavelength Division Multiplexing (DWDM) transmission capacity over ultra long-haul Terabit networks.

In one trial, the Company achieved a 3,000-km transmission of 80 DWDM channels at 10 Gbit/s each, using Raman amplification pioneered by Alcatel. In the second trial, the Company demonstrated a 250-km unrepeatered transmission span with 32 channels at 40 Gbit/s each. These records for transcontinental transmission were set with optical systems that soon will be commercially available, fulfilling customer needs for more bandwidth at a lower cost.

The first breakthrough will allow operators for the first time to implement ultra long-haul transmission in their networks on existing fiber infrastructures without building additional expensive intermediate terminal stations as is required by standard techniques. The demonstration concerns a groundbreaking 3,000-km reach at a 10 Gbit/s channel speed using Alcatel's commercially available 1640 Optinex™ DWDM transport system. The record involves transporting 80 DWDM channels, each operating at 10 Gbit/s over a 3,000 km G.652 Single Mode Fiber (SMF). Error-free transmission is achieved through dual-stage hybrid Erbium/Raman amplifiers spaced out at 80 km each, the same spacing already found in today's long-haul networks. This would allow the transmission of all the information contained in a one-mile-high book from San Francisco to Chicago over a single fiber in one second.

The second breakthrough demonstrates the viability of multi-wavelength 40 Gbit/s transmission in existing infrastructures, and is key to the rapid development of terrestrial and coastal networks. The demonstration concerns the longest single-span unrepeatered transmission distance (250 km) ever achieved for 1.28 Tbit/s capacities on standard silica core fiber using 40 Gbit/s channels. To achieve such a performance, two key technologies were used: Raman amplification, distributed along the span, and enhanced large-effective-area fibers, which minimize nonlinear power conversion and improve receiver sensitivity. The use of 40 Gbit/s as the channel granularity enables a four-fold reduction in channel usage, which yields a substantial reduction in the overall cost of the network.

http://www.usa.alcatel.com/events/suprcomm2000/press/scpr_060700_3.htm