planning for the future

THERE’S NO REAL DEMAND FOR 40GBPS optical equipment just yet, but some are starting at least to talk about it again.

Serge Melle, vice president of technical marketing for Infinera, told xchange at the recent OFC/NFOEC show, that during the telecom bubble all the vendors and service providers would try to outdo each other on bandwidth and various technologies. At that time, 40gbps technology was part of the race. “But, literally, in the last four years there has been no activity on 40gig,” Melle says.

However, now that the industry is stabilizing and telcos at least are entertaining the idea of delivering new bandwidth-intensive services like video, some vendors at OFC/NFOEC say, telcos are telling suppliers they need to have a roadmap to support 40gbps on their optical platforms without requiring a total equipment overhaul.

That’s why Mahi Networks Inc. at the OFC/NFOEC show had a sign in its booth promoting the fact that it plans to support 40gig as demand requires, says Ron Longo, vice president of worldwide marketing at Mahi.

Melle says he expects to see real demand for 40gig equipment in the next 12 to 24 months. “But it’s not going to be a fullblown, everywhere, technology,” he adds. According to Melle, MCI Inc. has been testing 40gig systems.

And T-Com, the fixed-network unit of Deutsche Telekom, in January announced plans to use Marconi Corp. plc’s Multihaul 3000 platform “as the first building block of Europe’s first 40gbps, high-capacity optical network.” According to a press release issued by Marconi, under a three-year framework agreement Marconi will supply T-Com with its Multihaul 3000 Dense Wavelength Division Multiplexing transmission platform, operating at 40gbps on each wavelength.

But Hendrik Van Der Meer, product marketing manager at Intel Corp., says interest from service providers in 40gbps today is just about “investment protection” in the future. “It’s still so expensive to do 40gig” because of the dispersion correction needed, he says.

However, Melle says integration using photonic integrated circuits, which Infinera offers, is bringing down the cost of 40gbps technology. New modulation schemes like dual-binary as well as DPSK and QPSK also are helping to address dispersion, making 40gbps more affordable, he adds.

fiber to limber up

In a move to help service providers lower the cost of deploying FTTx technology, Corning Inc. is working on “bend-optimized designs” for its fiber, Barry Linchuck, director of global product line management-optical fiber at Corning, tells xchange. Fiber that is more flexible could allow service providers to jam more fiber into a confined space, allowing for the “miniaturization of cabinets,” according to Linchuck. Corning expects to come out with the new, bendy fiber later this year.

In light of the new demand for bandwidth fueled by IP-based services like IPTV, video on demand and broadband Internet, Mahi Networks has introduced an expanded line of optical Ethernet transponder cards for its Vx7 Multi-Service Core Transport System (MCTS). New is a 10gbps transponder with 10 small form factor client interfaces supporting any combination of gigE, Fibre Channel, ESCON and FICON services. The transponder uses generic framing protocol and virtual concatention service adaptation layer to support full-rate and rate-limited services. Client interfaces are muxed using Mahi’s ADM-on-a-Wavelength technology, providing add/drops at any node and wavelength reuse on the ring. Also unveiled at OFC/NFOEC by Mahi was a universal 10gbps transponder with XFP client interfaces supporting 10gigE LAN PHY, 10gigE WAN PHY, OC192, STM64 and G.709 services.

Grande Communications Networks Inc. plans to deploy NexCor fiber and Evolant preconnectorized technology in its PON-based, FTTH network in Texas. Grande expects to pass 23,000 homes in Austin and San Antonio with the FTTH network this year. Barry Linchuck, director of global product line management-optical fiber at Corning, says that Grande is using NexCor — a single-mode fiber specified for all PON transmission wavelengths — to carry PON-based analog video traffic. He explains that some companies like Grande are opting to offer analog video services because analog technology doesn’t require a set-top box to deliver video as would digital video services. However, he adds, analog video requires a lot of power, and high power levels can result in what is known as the SBS effect, which creates a power limitation. So Corning with its NexCor product raised the SMS limit by 3dB more, allowing a service provider to launch twice the power in a single-mode fiber for longer distances in PON or to allow the carrier the ability to split it.