SilkRoad on track to initiate field tests

SilkRoad Inc., a San Diego startup that created a significant commotion with its Wall Street launch last November, is field testing its first commercial products. After generating intense interest and some skepticism concerning its bidirectional, single-laser transmission technology-which SilkRoad claims will increase bandwidth capacity over a single wavelength-the company announced in late July and early August three optical transceiver lines based on its patented refractive synchronization communication (SRSC) technology.

Scheduled to become commercially available in the fourth quarter, the entry-level optical transceivers in SilkRoad's Emissary 1000 and Pathfinder 2000 product lines target telecommunications and cable-TV providers offering analog and digital voice, video, and data services in the enterprise and metropolitan-area markets.

Meanwhile, the Ambassador 3000 optical transceiver line for long-haul, carrier-grade networks, although announced, is not expected on the market for at least another year. "It involves significantly more testing in terms of carrier-grade qualification in the field," says Bob Freeman, vice president of operations at SilkRoad. "As a small company, we put our resources into launching our technology with products that can respond quickly to the market, which is cable TV and the enterprise and the metro. If all of those are moving smoothly, the carrier product will be launched next year."

SilkRoad's SRSC-based systems use a modulated single-wavelength laser beam on a single fiber to carry multiple electronic signals up to 500 km. The technology allows for higher bandwidth at less cost over a single wavelength compared to multiple-wavelength technologies using multiple lasers such as dense wavelength-division multiplexing (DWDM), according to company.

"SRSC is the first coherent light-transmission technology that has ever existed," explains Freeman. "DWDM implementation certainly has a light-transmission capability, but it is not coherent. Our coherent transmission is useful for both the analog and digital signals traveling together. In a DWDM system, typically, you can't do that. And it boils down to signal-to-noise ratio requirements for analog signals versus signal-to-noise ratio for digital signals. Our proprietary way of putting the signal onto the wave allows us to do that.

"When you have coherent transmission, it gives you the capability of going in two directions on the same wavelength," continues Freeman. "If you have noncoherent transmission, you have to do that on two separate wavelengths spaced apart based on the amount of information that you are putting on them. So coherent transmission allows us to expand the capacity."

The first product in the Emissary 1000 optical-transceiver line for enterprise networks, the Emissary 1200, supports up to four mixed-technology channels--OC-3 (155.52 Mbits/sec), OC-12 (622 Mbits/sec), digital video, and digital data--or one OC-48 (2.5-Gbit/sec) channel over a single wavelength. SilkRoad has plans to introduce a 1400 model supporting up to eight mixed-technology channels or two OC-48 channels and a 1600 model carrying up to 16 mixed-technology channels or four OC-48 channels.

"We have not developed an OC-192-that doesn't mean that we won't," says Freeman. "On our first offering we won't do that. There is some rationale behind not going to an OC-192 in a metro loop. The metro would really like to have some OC-1s, T1s, Gigabit Ethernets, and an assortment of lower-number frequency channels because that gives you granularity and it gives you accountability on a much more discrete level. The metro obviously has a lot of people on it, and the more people you can assign a channel to, the better your model is for handling the information. Our network architecture allows us to do that. We can chop a single wavelength up into two OC-48s or 16 OC-3s or 64 OC-1s, or....it just keeps going."

The first offering in the PathFinder 2000 optical-transceiver line, targeted at cable-TV/telecommunications providers, is the PathFinder 2200. It provides up to four separate frequency bands of information on a single wavelength. Each band can transport and receive up to 1.5-GHz radio frequency (RF), a digital electrical spectrum of up to 650 MHz, or OC-3 or OC-12 signals. Future products include the PathFinder 2400 supporting up to eight frequency bands and the PathFinder 2600 carrying up to 16 bands. The company has also introduced a return-path aggregator, the PathFinder RPA 2020, and an add-on module, the PathFinder Cross Connect 2040.

The announced offering in the Ambassador 3000 optical transceiver for carrier grade networks is model 3020, which will transmit 20 Gbits/sec with up to eight mixed-technology channels--OC-3, OC-12, OC-48 and STS-3, STS-12, and STS-48. Other planned Ambassador products include the 80-Gbit/sec 3080 model with up to 32 mixed-technology channels and the 160-Gbit/sec 3160 model with up to 64 mixed-technology channels. The company also announced the NeTRAK 4000 Element Management System (EMS), transaction-based management software designed for multivendor networks.

Although SilkRoad has delivered its field-test products in a timely fashion and several analysts are impressed with the SRSC technology, the new offerings remain unproven, despite a few successful demonstrations. The field tests will go a long way toward either creating or diminishing customer confidence. SilkRoad has not disclosed the names of any field testers, due to confidentiality agreements, according to Freeman. (Level 3, however, is one carrier that is seriously looking at the technology, according to sources.)

Meanwhile, some analysts are willing to speculate on the technology's future. "If it works to the potential that I think it will," says Ken Kelly, senior telecommunications analyst at Dataquest (Denver), "it will definitely give DWDM some competition." Kelly expects the technology, if successful, to potentially challenge DWDM in the emerging metropolitan and enterprise markets. "It's going to be an uphill battle, but it could fit very well into the DWDM-type environment," he says. "It can be more economical because the technology itself uses just one laser, instead of multiple lasers as DWDM does."

The long-haul market in North America has "pretty much bought into DWDM," observes Kelly. DWDM technology, first introduced in 1996, is primarily used to increase the capacity in backbone networks. In 1998, DWDM systems represented about 20%, or $1.9 billion, of the $8 billion in optical-transmission equipment shipped in North America, according to Dataquest. "I would still urge a little caution," continues Kelly. "It's a technology as far as I'm concerned, it's not a system yet--especially in telecommunications. I haven't seen it in a telecommunications system yet. We expect 99.999% uptime deployed in the public-switched telephone network, and I don't know that this technology is capable of doing that because I don't have enough information on it yet.

"I did see it demonstrated and it worked fine for television," adds Kelly.

"If SilkRoad works as advertised, I think carriers will beat a path to their door," says Jeffrey Kagan, telecommunications industry analyst at Kagan Telecom Associates (Atlanta). "The bottom line is the phone companies of tomorrow look nothing like the phone companies of today. It's all about bandwidth. Unleashing the potential of unlimited bandwidth is going to be key to carriers thriving in tomorrow's marketplace," says Kagan. "If SilkRoad can help companies squeeze even more bandwidth out of their networks, they can't miss."

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