Wireless Andrew
- By Michael Fickes
- 05/01/00
More and more Carnegie Mellon University (CMU) students, faculty members, and staff fail to close their laptops properly before heading to the next class or meeting.
You see it all the time on CMU’s Pittsburgh campus. There goes a student with a laptop under his arm, while a magazine protrudes from the folded machine, preventing the latch from engaging. Coming from the other direction, a professor has jammed a scarf into her laptop to prevent it from snapping shut.
Blame it on Wireless Andrew. But don’t call it sloppiness. Call it technological progress.
Freedom From Wires
Wireless Andrew, a CMU networking system five years in the making, now enables laptop users to connect to the university’s computing network as well as to the Internet without cables. Users can tap into the system anywhere within the range of campus buildings equipped with wireless access points. They will remain connected as long as they don’t shut their computers down.
An access point is a receiver and transmitter with an antenna that communicates with properly equipped computers and connects them to the Wireless Andrew network, which then connects to the university network and to the Internet.
“By June, we’ll have 31 buildings equipped,” says Charles R. Bartel, CMU’s director of operations for computing services and project director for Wireless Andrew. Those 31 buildings form the academic core of the CMU campus and include classroom, research and administration buildings, as well as the exterior courtyards and walkways between those buildings. When complete, Wireless Andrew will dot the buildings with approximately 400 access points and provide wireless access to people inside and outside.
From Robots to Laptops
Wireless Andrew’s roots at CMU go back more than five years, when researchers involved in the university’s world-renowned Robotics Institute began to think about the problems associated with mobile robots.
Robots that move from place to place must have wireless capability. The farther the robots go, the more wide-ranging the wireless network must be.
To facilitate its robotics research programs and other mobile computing projects, the university moved into wireless networks in 1995. “We decided that our research programs would benefit from a common wireless infrastructure,” Bartel says. “At the same time, we saw that the prices for laptops were falling, while the capabilities were beginning to rival desktops.
“One of the chief benefits of a laptop is that it enables you to take your computing environment with you. In the Internet world, a computing environment is closely tied to the network. So it makes sense that, if you need to carry your computing environment, you also need to carry a seamless network communications capability.”
Is Wireless for You?
A wireless network that supports a mobile robotics program makes sense. But extending the program to seamless operation for laptop users across campus seems to stretch the point. Why not shut the computer down, move, plug in and start up again?
“That’s a question I’m often asked,” Bartel says. “My answer is that I see more and more people moving around campus without shutting their laptops down. So this paradigm has changed.”
Some universities may identify a wireless network as necessary support for research programs, just as CMU. But what about a small liberal arts college?
Certainly, university planners must identify a compelling reason to install a wireless network, agrees Bartel. Such a reason, he suggests, might arise as a growing number of institutions require students to purchase laptops for use in class.
How useful will students find their computers if they cannot connect to a network in class? How much will a university pay to install access jacks and cabling throughout classroom buildings with large lecture halls, regular classrooms and seminar room?
Of course, that raises the question of how much a wireless network will cost.
Funding and Functions
Original funding for the CMU program came in 1995, through a $550,000 grant from the National Science Foundation earmarked for the establishment of a mobile computing program.
Working as a partner with AT&T, now Lucent Technologies, CMU designed and deployed a prototype system in five buildings in the years that followed. When the project began, wireless technology offered limited capability. Older wireless systems served as an alternative to cabling between buildings or provided limited mobility for a few computers that might be moved every month or so.
CMU’s needs altered the standard concepts of wireless building-to-building communication and limited mobility. “We needed a system that would allow constant movement from point to point,” Bartel says. “We worked with Lucent to develop a design based on this view of mobility.”
Three years ago, Lucent approached CMU with an offer. Researchers had developed a new standard for wireless networking around the CMU prototype and wanted to prove the standard on the CMU campus. “Lucent granted us 400 access points, 400 pieces of equipment,” Bartel says.
Today’s Wireless Andrew begins with the 400 access points positioned in campus buildings. Each access point requires a power source and associated cabling. In addition, the access points tie together, using dedicated cabling within each building and tapping into available fibers in existing fiber optic cabling that runs between buildings.
“The architecture of this system creates a parallel wired network for wireless operation,” Bartel says. “The wireless network connects to the campus network, which is connected to the Internet. The reason we’ve done it this way is to facilitate seamless roaming. For reasons related to networking technology, if we tied the wireless network into the campus network at each building, individual users would sometimes have to restart their computers as they moved from building to building to reestablish a network connection. Our parallel network design solves this problem and offers roaming connectivity across the campus.”
Bartel hesitates to quote actual costs since they will vary from campus to campus depending upon geography and system architecture. He estimates, however, that preliminary budgets should allow about $1,000 for each piece of access point hardware plus another $1,000 per access point for cabling and system design costs.
System users face minimal costs. Plug-in cards that give computers the capability of logging onto a wireless system range from $100 to $200.
What’s next? Someone should figure out how to close a laptop without shutting it down -- before students begin breaking their laptop screens.