Wireless at West Point

Each freshman at the U.S. Military Academy at West Point last fall received a Dell Latitude C840 notebook PC for use on a new, wireless classroom network.'The military is relying more and more on IT,' said Col. Donald Welch, associate dean for information and educational technology. He said the notebooks introduce plebes to technology they will be using in the field, and in the meantime the academy will make the most of it for education.'About five years ago we started looking at wireless as a way to enhance education,' Welch said. 'The older IEEE 802.11b wireless standard had some significant bandwidth constraints. We knew when 802.11a came out, that was the way we wanted to go.'For the fall semester, the academy installed wireless access points from SMC Networks Inc. of Irvine, Calif., in 95 classrooms at Thayer Hall, the largest academic building. Freshman English and math classes used their PCs to share work and run simulations while the academy evaluated how to support the network.It was successful enough that psychology classes have joined the pilot, and the entire campus'six academic buildings, the library and student union'will be connected with 369 access points by summer. The number could go as high as 500 as new applications come along, Welch said.Although every classroom will have wireless access this year, it will be several years before all are used, as the class of 2006'the first to be issued notebooks'moves through.Student computers are nothing new at West Point. Cadets have had desktop PCs for 16 years, and the barracks have Fast Ethernet connections. Each classroom also has wired network connections for the instructors.'We've spent quite a bit of money upgrading the barracks,' Welch said.A fast connection and a PC can be a temptation to downloading things like pirated music files, however.'We look for it and take disciplinary action,' Welch said. But the academy treats music piracy as an ethical issue rather than a technical one. 'One of the things we teach here is values,' he said. 'We want to instill in them that stealing in cyberspace is still stealing.'The move of student computers into the classroom had to wait not only for mature wireless technology but also for notebooks that could equal desktop PCs in length of life and functionality. Cadets get only one computer for their four years at the academy.'We had gotten to the point where we could do four years on a desktop system,' Welch said, but notebooks are only now approaching that kind of longevity. They will be upgraded between the students' sophomore and junior years.Once the decision was made to go ahead with mobile computing, 'installing a wireless network was not that hard,' Welch said.The West Point application was straightforward, said Tony Stramandinoli, SMC's marketing director, using SMC2755W EZ Connect access points and SMC2735W PC Cards. The access point retails for $299 and the card for $149; SMC sells them bundled for $199.The 802.11a standard has higher bandwidth'a theoretical maximum of 54 Mbps compared with 11 Mbps for the 802.11b standard'but it sacrifices range. The high-bandwidth access points have a range of only about 60 feet compared with up to 300 feet for their 802.11b cousins. Putting an access point in every classroom eliminates the range restriction, however.Nor should network congestion be a problem. The largest classes at West Point have only 18 students. Counting the instructor, each access point will have 19 users at most. The access points are designed to handle up to 64.'It's not a lot for sharing 54 Mbps of bandwidth,' Stramandinoli said.Of course, they won't be getting the full 54 Mbps. Real-world wireless access averages about half of theoretical throughput, and in the West Point environment 'they're getting about 22-Mbps to 28-Mbps connections,' Stramandinoli said. That's a long way from the 100-Mbps rates back in the barracks, but 'pretty good for wireless,' he said.The users don't actually share the bandwidth. Rather than each user having one-nineteenth of the available pipe, each connection bursts to the full 22 Mbps or 28 Mbps while the others wait in line for the circuit to open.'That's a basic of Ethernet, not of wireless technology,' Stramandinoli said.The main hurdle in setting a wireless network up at the academy was security. 'We're a part of the Defense Department, and we have to comply with DOD security standards,' Welch said. In fact, he said, West Point took the lead in establishing those standards: 'We helped to find out what you need to do to secure a wireless network.' And because the 802.11 Wired Equivalent Privacy standard is weak, 'you pretty much have to buy a third-party solution.'The academy settled on the WirelessWall software suite from Cranite Systems Inc. of San Jose, Calif. The suite includes a policy server to set access policies, a controller that separates wired and wireless networks and handles encryption, and client software for authentication and encryption.WirelessWall uses X.509 certificates so a client can verify the network's identity before exchanging credentials with the access controller through an encrypted link. It follows the Advanced Encryption Standard with 128-bit keys at Layer 2.'We're trading off a little bit of latency' for the strong encryption, Welch said. But AES is an efficient algorithm with little impact, even on mobile devices.That makes the wireless architecture more secure than the wired environment, 'so we are introducing no vulnerabilities,' Welch said. 'Our biggest problem is on the client.'The cadets own their computers and can load their own software, which sometimes interferes with the access and security software. The academy has faced this dilemma since 1987 on the wired network, 'so we have to climb the learning curve again. We are investigating ways to harden the configuration,' Welch said.