Point to point
Laser bridges offer alternatives for data transfer
When you’re using binoculars to scout sites from the top of buildings in Washington, D.C., it’s probably no surprise when you get a visit from men in dark glasses.
“I remember being up there, and Homeland Security wanted to know what we were doing on the rooftops. We were about 27, 30 stories up. … You could see the high-rises, the monuments, going to D.C. We were just tickled they were paying attention,” recalls Rowland George, vice president of Henrico County-based telecommunications engineering and installation firm NDEC.
A network design and engineering firm, NDEC specializes in telecommunications work such as engineering and design plans for fiber-cable installations to cell phone towers. The company also installed fiber-optic cable infrastructure and SMART Boards for Henrico County Public Schools.
But among its lesser-known services is the installation of laser bridges, a nifty, optical data-transfer system that can deliver a constant data stream of up to10 gigabytes between two points as far as five miles away, via invisible, pencil-thin lasers.
A pair of laser transceivers, which somewhat resemble tourist viewfinders, must be mounted within an uninterrupted line of sight, usually on rooftops. Companies typically use the technology to connect internal computer systems or intranets between buildings.
The laser-bridge technology is about 15 years old, but it’s improved drastically since it first came on the market, George says.
Systems range from about $30,000 to $75,000 depending on how large a data stream a company requires. The system is often used in historic districts and areas where it is cost prohibitive to install fiber-optic cable, either because there’s no existing infrastructure or the property between the two points to be connected is owned by other interests. It’s especially popular in Europe, George says.
“We’ve got over 16,000 [laser bridge] links around the world. … We’ve got quite a lot of product out there,” says John Taylor, vice president of sales for San Diego-based LightPointe, which manufactures the laser bridge hardware.
NDEC has installed laser bridges on the East Coast from Pennsylvania to North Carolina.
In the Richmond area, NDEC clients using the laser bridge include ad firm The Martin Agency and auto dealership Richmond Ford. In Northern Virginia, the authorized installers for the system are NDEC and Maryland-based firm American Telecom Solutions, whose laser-bridge clients include Fairfax County-based defense contractor General Dynamics and the Alexandria-based nonprofit National Center for Missing & Exploited Children.
One of the laser bridge’s advantages, Taylor says, is that “it’s highly secure, and it has very high bandwidth you can’t get from Wi-Fi bridges.”
A typical Wi-Fi system is protected only by software encryption. Radio frequency waves radiate from the point of broadcast and can be detected and intercepted by anyone in range. The laser bridge system is pencil-thin, invisible and virtually undetectable. The data already are encrypted, and to hack into it from outside a building, you’d have to install another compatible transceiver in the same narrow, physical line of sight that the laser is traversing, George says.
The latest systems come equipped with eight lasers and are equipped with auto-tracking technology to compensate for the swaying of tall rooftops. Because the systems are usually high in the air, they’re really interrupted only by severe weather. “Birds flying through it doesn’t affect it, but if they build a nest on [the transceiver], then that’s an issue,” George says, laughing.
The Martin Agency installed its system in 2010 to connect employees in a building about a block and a half away from its headquarters to its company intranet, says John Cartier, a vice president and network operations manager for the ad firm. The system is robust, he says, and can support voiceover IP phone service in addition to the company’s intranet.
The cost of the laser-bridge system was about the same as it would have been to subscribe for a few months to a 1 GB-per-second connection from a telecommunications provider and connect to the intranet via a virtual private network (VPN), Cartier says. Unlike a connection from an Internet provider, the laser bridge requires only a one-time capital outlay with no subscriptions or ongoing fees.
For The Martin Agency, the laser bridge also made sense because NDEC could install it and get it up and running in six hours, whereas it would have taken many months to get permits and permissions to install physical cable over a two-block distance in a crowded, historic, downtown district.
NDEC also installed a laser bridge for Old Dominion University. It used the system from roughly 2003 to 2009 to connect its campus intranet to ODU’s Frank Reidy Research Center for Bioelectrics, which was then housed about 1.25 miles away in the Norfolk Health Department’s building. Installing fiber-optic cable over that distance on property that the university didn’t own was too expensive a proposition, so ODU installed the laser bridge, says Wayne C. Jones, the university’s director of information technology infrastructure. ODU stopped using the laser bridge after the bioelectrics center moved into ODU’s Innovation Research Park on the university campus.
ODU’s laser bridge worked pretty reliably during the years it was operational, but there were a few snags, Jones says. For one, a few years after ODU installed the laser bridge, Sentara Healthcare built Virginia Heart Hospital nearby and the construction disrupted the lasers’ line-of-sight connection, so one of the laser transceivers had to be moved, and a cable had to be run a short distance from the relocated transceiver to the ODU researchers’ office. Additionally, Norfolk is prone to heavy fog and that took the system down about four or five times, sometimes for several hours, Jones recalls.
“If you have a very hard downpour of rain or snow or fog, your signal is going to be affected,” Jones says. “It would not work for anyone in emergency management or banking or any [industry] in which … the loss of a data packet would spell financial doom or life or death.”
Summing up the laser bridges, George says, “A lot of people don’t know about it, and as we tell everybody, your No. 1 choice would be hardwired. That takes fog and snow and things you don’t have control of out of the equation. This is more of a niche product where you need a connection between points A and B and … [laying cable is] either cost-prohibitive, or you’ve got real estate or infrastructure issues.”