FT Lauds WDM-PON's Potential

France Telecom SA (NYSE: FTE) today revealed why it's involved in the Sardana WDM-PON trial that's underway in Europe: The cost saving potential is enormous.

Sardana, or Scalable Advance Ring-Based Passive Dense Access Network Architecture, to give its full name [ed. note: shouldn't that be Sarbpdana?], was revealed earlier this year when Tellabs Inc. (Nasdaq: TLAB; Frankfurt: BTLA) unveiled its involvement in the closed group trial, in which Intracom Holdings S.A. and a bunch of European research and development institutes are also involved. (See Tellabs Lays Out WDM-PON Plan.)

Today at the ECOC 2008 optical technology show in Brussels, Philippe Chanclou, senior research expert at France Telecom R&D, provided an update on the three-year project, and included details about the potential magnitude of savings the French incumbent operator might achieve if it deploys WDM-PON technology on a broad scale.

Currently FT's fiber access service developments are based on GPON and involve having an active network element, the OLT (optical line terminal), in a local exchange, which (in theory) can provide broadband connections of up to 100 Mbit/s downstream to as many as 64 customers per OLT port. (See Vendors Vie for FT GPON Deal and FT Fleshes Out FTTH .)

FT has already deployed such equipment in France and Slovakia, and plans to have about 150,000 fiber-to-the-home (GPON) customers in its domestic market, where it is charging €44.90 ($65.95) for unlimited Internet access, unlimited telephony, and hi-definition IPTV services, by the end of 2008. (See Orange Does FTTH in Slovakia.)

But service development advances are already eating away at that GPON's bandwidth limits -- France Telecom plans to offer 3D TV services to mobile users by the end of 2008 and to flat screen TV users by 2011 at the latest. That service to domestic flat screen TVs will eat up between 50 Mbit/s and 90 Mbit/s, believes the carrier.

Chanclou told Light Reading that FT is interested in a network topology that has only passive components between the metro network and the end users, each of which, in a WDM-PON setup, would be connected with a dedicated wavelength. Such a move would save FT a great deal of money because it would need far fewer local exchanges, and cut down on power consumption and taxes (FT is taxed for each network element it houses in its local exchanges).

For example, in Northwest France, FT currently has 820 local exchanges (central offices) to house its broadband and voice equipment but believes that a WDM-PON deployment in the same region would require only 45 local exchanges.

That's because the service reach from regional WDM optical rings, using WDM-PON equipment, would be up to 1,000 kilometers, with each pair of fibers running to a local area supporting up to 1,000 customers, and providing downstream capacity of 100 Mbit/s (minimum guaranteed) and up to 10 Gbit/s.

"We would like to have expertise in the systems of tomorrow. GPON gives us what we need now, but we need a technology for the future that will have long reach and be capable of delivering speeds of up to 10 Gbit/s," says Chanclou.

The Sultana Sardana group is currently testing WDM-PON technology in Tellabs facilities in Espoo, Finland, and plans to conduct a trial in the town of Lannion in France in 2010.

At the end of the project the Sardana group plans to feed its findings into standards bodies, and also hopes to collaborate and have discussions with other groups that are exploring the potential of WDM-PON, which has emerged as a hot future technology during 2008. (See AOI Targets WDM-PON, WDM-PON Faces 10G Challenge, Unknown Document 16074, Ignis Opens in China, Ericsson Joins Cost-Cutting WDM-PON Team, and ADC Does WDM-PON.)

— Ray Le Maistre, International News Editor, Light Reading