Optical wireless technology remains a niche market. But it has come to the rescue of Memorial Sloan-Kettering Cancer Center in crowded Manhattan, where digging a trench for an optical cable could take months, given the need for construction approvals.

The cancer centre operates without paper or medical charts, so all data and voice connections need a backup pathway, CIO Patricia Skarulis said last week. Her staff has tried just about every kind of networking technology, including leased lines and microwave communications. It discovered optical wireless three years ago, installing equipment from LightPointe as a backup link between two buildings.

Optical wireless is cost-effective
Last summer, the centre deployed its third optical wireless link. This time, however, it used the optical technology as a primary link that is backed up by two T1 land lines, Skarulis said. Optical wireless is “reliable and higher-speed than the alternatives and cost-effective,” she added.

For example, Skarulis said Sloan-Kettering has found that an optical wireless link pays for itself within seven months compared with the cost of a leased line that offers lower throughput.

An optical wireless connection running at 1 Gbit/s costs $50,000 to $60,000, she said, contrasting that with a monthly fee of $10,000 for a leased 100 Mbit/s fibre-optic cable.

Pat Carragee, director of information systems at the cancer center, said it took two days to install the newest optical wireless gear in the two buildings being linked. The IT staff used rooms with windows instead of doing a more complicated rooftop installation, Carragee said.

It's a niche market
Optical wireless, first developed in the 1960s, is a line-of-sight technology that uses beams of light as the primary data path. Jack Gold, an analyst at J. Gold Associates in Northboro, Massachusetts, and Gartner analyst Bettina Tratz-Ryan both said the market for the technology is still small, with several vendors generating less than $200 million in annual sales globally.

But Gold and Tratz-Ryan said optical wireless can greatly reduce deployment times for network managers and offer high bandwidth at a comparatively low cost.

Sloan-Kettering has used equipment from San Diego-based LightPointe on all three of its installations. Next year, the center plans to install a fourth optical wireless connection to link end users in a 20-story research tower to its LAN, Carragee said.

Last summer’s installation offers transmission speeds of 1 Gbit/s, as will the one coming in 2006. That’s fast enough to support video applications used in training and psychology counseling, Carragee said. The distance covered by the optical links ranges from two to seven city blocks, or as much as a half-mile, he added.

Tratz-Ryan said LightPointe is the largest optical wireless vendor, with Canon and Proxim Wireless as its top competitors.

Despite the potential benefits of optical wireless, Gold said he doesn’t expect the market to grow in coming years, especially with the advent of WiMax wireless technology. WiMax promises high-bandwidth connections over several miles between transceivers, he said.