West Point goes wireless

Computerworld - WEST POINT, N.Y. -- The problem Col. Donald J. Welch faced at the U.S. Military Academy at West Point is the same one many businesses face today: He wanted to create a high-traffic wireless LAN that could serve hundreds of users spread over a campus of buildings of various designs and materials that would still meet U.S. government security requirements.
The cadets at the academy had to be able to use their laptops from anywhere on campus, said Welch, associate dean for information and educational technology.
His first move was deciding between the 802.11a and 802.11b wireless standards. Although 802.11a offers higher transfer speeds, 802.11b is much more common and is compatible with the still-emerging 802.11g standard. Welch opted for 802.11a, which he felt held several advantages.
First of all, 802.11a has eight nonoverlapping channels, he said, as opposed to 802.11b and 802.11g, which have three nonoverlapping channels in the U.S. And 802.11a operates in 5-GHz frequency, whereas 802.11b and 802.11g operate in 2.4-GHz band. Access points using 802.11a also have a shorter range than 802.11b/g access points. So, Welch could pack more access points into a smaller space without worrying about channel overlap and possible conflicts that could lead to poor service for users.
"802.11b was not going to deliver the bandwidth needed," he said.
Having the access points closer together -- one per classroom or one for every 20 users -- allows greater bandwidth for the transfer of larger files and applications. And the applications West Point cadets use can get very large. For example, Welch said, cadets might use a simulation of the battle of Gettysburg in class, one in which a key aspect of the battle can be changed, forcing the cadets to change their battle plans on the fly.
According to Welch, 300 users in multiple classrooms could be running such a war game at the same time, something that would require high bandwidth.
With that decision made, West Point moved ahead with its wireless plan. It has so far installed 369 access points from Irvine, Calif.-based SMC Networks Inc.. That number will likely go as high as 500.
During the rollout, Welch said he has found that the system sometimes needs to be tweaked for best operation. After the initial installation, "you discover lots of places where they need them," he said. One advantage 802.11a has over 802.11b/g is that it can penetrate stone walls.
At a recent 802.11 Planet conference in Boston, WLAN expert James T. Geier said he has found that 802.11a