Many schools are beginning to consider using wireless LANs as opposed to a cabled LAN. WLANS transmit and receive data over the air using the radio frequency technology, minimizing the need for wired connections.

Potential Educational Use
In an educational environment, users with notebook computers could connect to the network without concern about the proximity of the network drop.  In my school for example, the network drops were placed in the most convenient location for the cabling installers, meaning on the hallway wall.  The best location for instructional purposes was not considered. Teachers have to work around the network drop’s location, which in most cases is not the best spot for teaching. With a wireless network, the teacher would be free to move the equipment to a location more conducive to instruction.

Universities are seeing potential in WLANS because students with notebook computers can connect to the university network for class discussions and to the Internet for e-mail and web browsing.

Some school districts are sharing the cost of Internet access by using wireless technology on a wide area network (WAN)

Who Makes It and How It Can Be Obtained
Wireless lans are becoming more reasonably priced and accessible.  For only a few hundred dollars, a home user can install a wireless network. PC Computing recommends the Proxim Symphony product line starting at about $129 for a PCI card (per PC).

The Symphony uses the 2.4GHz spectrum shared by the latest cordless phones.  Although advertised performance is 1.6Mbps, actual speeds are closer to 527Kbps, less than half the promised speed. In wireless LANs, speed depends on how far away the systems are from each other and where they’re located.  Range is limited to about 150 feet.  The network will transmit through walls and ceilings, but it’s best to keep obstructions between the systems to a minimum.

For business and education users, 3Com has an AirConnect wireless network. It offers 11 Mbps speeds using the same 2.4 GHz spectrum that Symphony uses.

Proxim, Intel and Motorola have all announced support for the HomeRF SWAP wireless standard. This allows products from different companies to work with each other.

Some Concerns
Some tech people believe that promised speeds for wireless LANs are a lot of hype.  John Dvorak writes in the July 7, 1999 issue of PC Computing "It’s possible to get 2Mbps to 10Mbps over a wireless network.  Of course, it barely works at all and is ridiculously expensive per seat. Sure, this will turn around—sometime in the year 2035."

Another problem for those schools wanting to connect two buildings is that they need to have a clear line of reception for the access.  Intermittent frequency loss can occur resulting in an unreliable network.

Data security is also a concern since radio frequency waves are easily intercepted.

How It Works
Wireless LANS use electromagnetic airwaves (radio and infrared) to transfer information from one point to another.  Several radio carriers can exist in the same space at the same time without interfering with each other if the radio waves are transmitted on different radio frequencies.  Wireless LANs tune to one radio frequency while rejecting all other radio signals on different frequencies.

Typically, a transmitter/receiver device, called an access point, connects to the wired network from a fixed location using a standard Ethernet cable.  The access point receives, buffers, and transmits data between the WLAN and the wired network.

Users access the WLAN through wireless LAN adapters, which are PC cards in laptop computers, ISA or PCI cards in desktop computers, or integrated within handheld computers.

Cost
It is difficult to get a precise cost on implementing a wireless LAN.  Part of the problem lies in the diversity of each site’s needs. Approximate costs are discussed at http://www.wlana.com/index.html , a consortium of WLAN providers including 3Com, Nortel, Nokia, and Lucent.

They site "more efficient use of space, and more in-class productivity" as one of the benefits of a WAN for education. According to a study they jointly sponsored, the main way that schools could save money was by buying fewer computers. They felt that a wireless LAN would allow for using more cart-mounted computers.

According to the study "Wireless LANs turned out to be very inexpensive on a per-student basis. Wireless infrastructure costs for the educational sector averaged $2308. In the study 1345 students benefited from the wireless solution which in an average configuration included 25 access points and 112 computers equipped with wireless adapters. The savings can be attributed to the utilization of cart-mounted computers and fewer network drops as a result of the wireless LAN. With carts, fewer rooms would have been required to be networked and populated with computers."

URLs For More Information
http://computer.org/student/looking/summer97/ieee802.htm
http://www.wirelesslan.com

Conclusion
I don’t agree with the reasoning that using a wireless LAN would cost less because fewer computers would need to be purchased. This reminds me of the logic that a person could save money by using public transportation. True, but what sacrifice is being made to save the money?

For schools that already are wired, a wireless LAN is almost a moot issue. The biggest saving appears to be in the time and expense of wiring. Since my school is already wired, it does not seem beneficial to go wireless. If we were to add an additional computer lab, it might be worth considering. It would be nice to have the classrooms use wireless technology for the portability, but I’m not sure that would be cost-effective.