Take it a little longer

ATLANTA—Although sometimes days in Atlanta seem too long, the distance a signal can carry over optical fiber without regeneration just can’t be long enough. This week at Supercomm, Hitachi Telecom detailed its new 128-channel DWDM system that is capable of sending traffic 8000 km without regeneration at 10 Gb/s without regeneration.

To achieve that distance the company is using erbium doped fiber amplifiers (EDFA) rather than Ramen amplification. The company also is using gain tilt compensation to help balance out the signal and extend it further.

The system that can go the longer distance is actually an enhancement to Hitachi’s existing Advanced Multiservice Network (AMN) 6100 that is being used by providers such as Global Crossing. This week, the company also revealed that Norlight Telecommunications, a provider based in the Midwest, is also deploying that product into their network.

The gain tilt compensation takes the signal out to 1000 km, but to reach the 8000 km mark, an optical signal expander module card is used, according to Alan Lewis, director of business development for Hitachi Telecom.

“You just plug [the OSEM] card into the line amplification site,” Lewis said.

In addition to the flexibility and efficiency service providers will gain from the added distance, the product can be used on short, medium and long distances, according to Lewis.
Liane LaBarba is Senior Editor at Telephony. She can be reached at labarba@airmail.net.