"Forks in the Optical Road"
The following article is from the January, 1999 America's Network Magazine. It examines two optical networking startups, each with their own unique way of packing optical for delivery.
The companies are:
Commercial Technologies Corporation (CTC, Culver City, Calif.)
Silk Road Inc. (San Diego, Calif.)
americasnetwork.com
Regards, Frank Coluccio
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"Forks in the Optical Road"
Two vendors claim to have better mousetraps. But will carriers listen?
By Annie Lindstrom
Choices, choices, choices — that's what today's
networks are about. Do so many choices make things better,
worse, both or none of the above? Carriers that thought they
had their arms around optical networking by embracing dense
wavelength division multiplexing (DWDM) technology may
want to cozy up to new technologies.
The newbies claim their products can save carriers more money — and allow
them to optimize the fiber they already have deployed or plan to deploy — than
they can using DWDM. However, carriers may shy away from new
approaches, especially if they have invested heavily in DWDM-based
strategies.
Most large interexchange carriers (IXCs) have used DWDM in their networks
for some time. Incumbent and competitive local exchange carriers (ILECs and
CLECs) have followed suit or are making plans to use it as well.
Vendors claiming to have a better mousetrap are vying for the attention of
network engineers and planners, as well as investors.
At Supercomm '98, Commercial Technologies Corp. (CTC; Culver City,
Calif.) introduced optical code division multiple access (O-CDMA; see
"Bar-coding fiber," July 1, 1998). Like DWDM, CTC's CodeStream
O-CDMA system places multiple transmissions on a single fiber, but it does so
using a single optical source rather than using a laser for each wavelength, as
DWDM requires. Instead, O-CDMA transmitters bar code and modulate
multiple signals onto a single fiber; receivers with corresponding bar codes peel
signals off at the appropriate endpoint.
This month, CTC will deliver its first product, a 16-channel system, to two
IXCs and two CLECs (both U.S. based) for lab and field beta testing,
according to CTC's chief operating officer, William Johnson. A major video
provider also will test the system. The video company is exploring the idea of
purchasing and repackaging the technology for carriers and cable television
(CATV) providers that want to transmit high-bandwidth video across their
networks, he says.
"They want to use O-CDMA to tie headends together to transport video
without having to use Sonet [synchronous optical network] technology or
codecs [coders/decoders]," Johnson says.
Investors are interested in O-CDMA. At press time, CTC had completed its
third round of financing and had raised $14 million, according to Johnson.
Since CodeStream's introduction, CTC has made the system more dense and
robust, and a bit cheaper to manufacture, Johnson says. Target pricing is still
$20,000 per end connection, a price that makes the system competitive with
DWDM systems, he notes. That being the case, the incentive to use O-CDMA
instead of DWDM is that it allows CLECs to provide seamless, all-optical
connectivity between the customer premises and the central office (CO), he
adds.
CTC is aiming its initial, point-to-point system at customers that would like to
implement DWDM at OC-12 rates, depending on affordability.
"Today, carriers can only afford to link to their fiber networks customers that
have revenues of $5,000 per month or more. That's 4% or 5% of biz
community, which means they have a network out there that can't deliver
services to any customers but that 5%," Johnson explains. "Adding DWDM to
that network to reach smaller customers increases the overall cost of the
network, which is already too expensive.
"DWDM takes you in the wrong direction. O-CDMA allows you to rip out all
the Sonet stuff in the middle. Putting O-CDMA on the network is like putting
DWDM everywhere on the network all at one time," Johnson adds.
CTC's goal is to help carriers serve 50% of the market containing customers
spending $2,500 per month.
Calling Marco Polo
Last quarter, SilkRoad Inc. (San Diego) introduced an alternative called
SilkRoad Refractive Synchronization Communication (SRSC).
The company's moniker refers to the ancient eastern trade routes used by
Marco Polo to transport silk and other items of wealth between Europe and the
East.
SilkRoad's goal is to help carriers transport a wealth of information across their
existing and planned optical networks. Unlike DWDM, SRSC uses a single
wavelength to send up to 200 Gbps of information through a single fiber today.
The system has the potential to reach speeds of 10 Tbps (terabits per second),
which is the capacity of fiber itself, according to Bob Freeman, vice president of
operations at SilkRoad.
SilkRoad's technology can simultaneously accommodate many different signals
in one pipe, including OC-48, FM radio, Motion Picture Experts Group
(MPEG 2), or digitally compressed signals.
"Using DWDM, if you want to use more than one OC-48 channel, you would
have to get another wavelength for each channel," Freeman says. "SRSC uses a
frequency tag, or clock, and we can clock as many of those signals up to the
level of our detector. The biggest difference between DWDM and SRSC is that
we only have one laser."
SilkRoad unveiled its product in late 1998 to business executives, analysts and
the media. SilkRoad demonstrated SRSC's ability to deliver, through a single
laser, 840 channels of satellite programming at 93 Gbps through a 100-km
length of fiber.
But that feat may not be enough to woo carriers. "Right now, they say they can
go up to 100 Gbps, but we are already transporting 240 Gbps in our network
today," says a spokesman from Sprint (Kansas City, Mo.).
SRSC technology refines a laser's output to one narrow line-width. SilkRoad's
patented external modulation process collects multiple channels before they are
introduced on the modulator. The system stacks the channels in a
four-dimensional optical space and transmits them across a single wavelength.
In addition, the SRSC can transmit its payload across any type of fiber,
Freeman notes. Thus, there is no need to install high-performance fiber to
accommodate higher speeds.
SilkRoad will introduce its initial system this quarter. It will provide carriers with
the equivalent of 32 OC-48 channels, Freeman says. (Systems released later
this year will provide more capacity, although Freeman declined to reveal
additional information.)
Even though SRSC does not yet match current capacity and speeds of existing
DWDM systems, SilkRoad claims its ability to allow carriers to transmit any
type of signal nearly 200 miles without regeneration through a single laser could
save oodles of money.
Yet analysts and carriers remain skeptical of the claims SilkRoad is making.
Some say they've looked at the product and determined that it's "not ready for
prime time." Others want to know more about company funding and investors.
"I'm quite impressed with what they are doing. It could make lot of difference in
the availability of high-bandwidth communications over the next couple of
years," says Hans von Braun, research director at Creative Strategies Inc. (San
Jose, Calif.). "The only question that came to mind is their financing. They are
privately held and have been close about the financing and funding they've
received to date. A project like this is going to take a lot of money."
SilkRoad chief financial officer Douglas Buie notes that since the product's
launch, the company has raised $13 million in two rounds of financing.
"We made it plain that the purpose of discussion during the launch was not
financing," Buie says.
"There is a lot of skepticism," counters Ken Kelly, senior analyst for Dataquest
(San Jose, Calif.). "This is so simple that carriers are saying, ‘Why hasn't one of
the biggies done it?' Some claim they have it or are looking at it. I don't know
why the biggies haven't done it. Why did two guys from out east invent the
airplane rather than a big company?"
Freeman adds that the biggest drawback to using a single wavelength to
transmit high-bandwidth signals at high speeds is "being the first to do it."
Carriers that have met with SilkRoad plan to take a closer look at the system,
according to Kelly.
Although one might expect SilkRoad to market SRSC to the IXCs first, the
system is a good fit for any type of carrier or enterprise, Freeman says. "We
thought we'd be concentrating on the long haul, but we found out that the
system scales all the way down to the short haul and enterprise markets.
DWDM doesn't carry itself down to these other networks," he notes.
DWDM's momentum is the biggest obstacle for SilkRoad; another could be the
high amount of security the system offers. The inability to access signals could
cause the government to voice concerns about the technology, von Braun says.
"As long as they don't promote that, they'll be fine," he notes.
Friend or Foe?
Although much of the discussion surrounding SilkRoad's launch has focused on
performance, SilkRoad's goal is not to pit its technology against DWDM.
"We aren't in there to fight where DWDM is going in," Freeman says. "The
technology could be offered alongside DWDM. DWDM vendors could use this
technology to expand their business. We are not interested in ruining DWDM."
SilkRoad executives prefer to partner with interested parties rather than license
the technology. However, the company has not met with DWDM vendors, says
Freeman.
"Right now, we are going to service providers and saying, ‘here is a technology
that can make you more money and let you provide services you will never be
able to provide using other technologies'," Freeman says.
At press time the company was hiring a sales force to spread that message and
was seeking a third-party distribution channel. Both CTC and SilkRoad will
need talented sales forces to get their feet in carriers' doors while they're still
open to new optical networking pathways. |
