Wireless at the Nuclear Cleanup - Page 2
September 09, 2004
As more of the buildings went cold and dark and were eventually demolished, CH2M HILL project staff and monitors from the Department of Energy and other agencies increasingly moved into huge mobile trailers that could be moved around the site. In some cases, Wi-Fi couldn't reach far enough to service the trailers in the locations where they were needed. Laying more fiber would be expensive. So longer-range wireless links, both point-to- point (PTP) and point-to-multipoint (PMP), became one requirement for the new network.
At the same time, new applications implemented by CH2M HILL and the various monitoring agencies involved in the project required more and more bandwidth. The data and VoIP requirements together were beginning to push the limits of Wi-Fi capacity. So higher bandwidth capacity was on the requirements list as well.
CH2M HILL was also encountering mysterious problems with Wi-Fi outages.
"All of a sudden we'd have a directional antenna go dark and we'd lose connectivity," Guthner explains. "We'd scratch our heads, but by the time we got out to the site to investigate, everything would be back up and normal. We were just going nuts."
Finally, they figured out what was happening. Huge cranes lumbering along the streets of Rocky Flats or stopped by a building were blocking line of sight between antenna sites.
"We saw it happen one day," Guthner says. So NLOS was also on the wish list.
Although CH2M HILL did consider other solutions, Redline appeared to deliver everything the project needed. Its flagship AN-50 product, designed for PTP and PMP broadband access and backhaul applications, works in the 5 GHz unlicensed bands and functions at up to 72 Mbps over the air. Range is up to 50 miles. It can function in NLOS mode -- though not at maximum range or throughput.
"In terms of specifications, flexibility and manageability, Redline stood out as a clear winner," Guthner says.
The Redline equipment is compliant with existing 802.16 and related standards. The company's vice president of marketing and product management, Keith Doucet, hastens to make clear that Redline is not claiming this is WiMax. Interoperability standards for WiMax remain to be finalized. Redline, which works closely with all the related standards body committees, is already building its own chipsets, though, and says it is the first with an 802.16 chip-level product.
CH2M HILL began installing the Redline gear in February and now has 27 AN-50 units in place. Ten are used as carrier units at hub points, 17 as subscriber units -- at the trailers where project staff work. Some units work in point-to-multipoint mode -- like the two on a central tower that provide 360-degree coverage of the site -- and some work in point-to-point mode to extend connectivity to remote trailers or back to the wired net.
The wireless network is only used for backhaul. Within the trailers, where anywhere from 12 to 90 people work, CH2M HILL runs copper to each workstation. "It's inexpensive," he points out. Plus, the company found when it tried to run Wi-Fi to the desktop, the additional overhead required for encryption over that last 10 meters slowed systems down too much.
Guthner had a good demonstration of the NLOS capabilities of the Redline equipment when a major snow storm shut the project site down earlier this year. At one point, the offsite network operations center received an alert that one of the wireless links was losing packets. IT staff remotely boosted radio power, which partly corrected the problem. After the storm passed and workers were allowed back on the site, they found that the Redline antenna had been blown right over and was pointing straight down into the ground -- yet it continued to provide a link, albeit degraded.
Redline and CH2M HILL are currently working on two new wireless projects at Rocky Flats, both of which will require true mobility. In one, the Redline wireless gear will extend the project network out to trucks moving around the larger 6,000-acre site doing soil samples to test for radioactive and other contamination. Redline will provide mobile wireless VoIP and data connectivity. In the other project, rail cars and truck trailers will be tagged with RFID transmitters to track their location and status.
CH2M HILL is also deploying the Redline gear in projects in the Middle East, including in Jordan and Iraq. The company works or has worked in over 80 countries and Guthner, who is also director of IT in its computer and information services group, says there will be plenty of other opportunities to use the Redline technology.