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March 1, 2001
Wireless as a Networking Solution
By Thomas C. Hashem
About 25 years ago, I got interested in amateur radio, otherwise called wireless. It wasn't wireless exactly. Sure the signal sent from my home to homes around the world traveled without wires, but my den and backyard were absolutely covered with wires. There were wires for radio equipment, antennae, speakers, tuners, and many other connected devices--all of which did not thrill my wife and kids. Today, connections are wireless Ethernet.
Recently I was contracted to find solutions for networking computer stations and computer labs that are in old and some cases temporary buildings sites. At these sites problems abound: there are no hung ceilings; and brick walls and cement floors are difficult and expensive to penetrate in the process of wiring computer LANs.
A typical wiring contractor will generally quote $125.00 per "drop". This means that the cost of connecting one computer to the network is $125.00, not including the cost of parts, which can easily add up to $1.50 per foot! Some of the more difficult drops can cost $500.00 if they involve 150 foot "run" along with the necessary cable, conduit, and connectors. Wiring panels and hubs or switches may also be involved.
I have seen a cost of $3000.00 to connect 10 computers to a LAN in an existing school building. Once this is done the potential for wiring problems, should a computer need to be moved or if a room location is changed, is huge. These problems include adding wiring, hubs, or switches that may be changed again should another move be necessary. Many times teachers find their desks "stuck" to one spot in the room because of a network wiring location--a limitation that happens with the best of advanced planning.
Now, I'm not suggesting that you cut all your Ethernet wires. In many cases wired LANs are the best possible solution. For one thing the wired LANs provide speeds of up to 100 mps (1 gig mps is possible) where wireless connections have a speed of about 11 mps. For some application problems, wireless might be your solution.
A number of manufacturers, including Intel, 3Com, D-Link, Linksys, Compaq, Dell, SMC, as well as many others, have developed wireless Ethernet equipment. Lately these systems have become less expensive compared to previously and the reliability and speed have been enhanced.
Currently, these systems cost about $150.00 per computer. Additionally, a wireless receiver costs anywhere from $250 to $1000 depending on location distances and the number of PC's you require to have access to the network.
Many school districts wish to "wire" a computer lab. If the computers are set up along the edge of the room(s) the wiring cost is reduced because of the lack of the need of "electrical poles". You see these poles in offices where it is either unlawful or unwise to let wires dangle from the ceiling. Another option, which is expensive, is to run wire conduits across the floor to carry wires to the computers.
A computer lab with a wireless LAN is a simple installation with an Ethernet card (NIC card) installed in each computer. Software is provided with the wireless card, and all the new wireless cards are plug and play. Then a wireless receiver is placed in a convenient location, either inside or outside the room. The range of the wireless device is as much as 300 feet, considering walls and floors.
In a lab, the computer department could run one Cat 5 cable from any location to the lab and mount the receiver high on the wall or on the ceiling in the room. The receiver will handle, typically, up to 32 computer workstations and some receivers will handle up to 64 computer workstations. The connection speed is 11 mps and will provide speeds faster than any Internet connection would need. File sharing and printer sharing would be possible as in any network. Other computers hundreds of feet away would have no problem communicating with this lab provided they were wired to the network or wired with a receiver wired to their room.
Wiring single room computers can also be effective with wireless. In many buildings a receiver placed in the corridor between classrooms would allow teachers to access the network or Internet by installing a wireless Ethernet card in their room computer(s). Installations of this type might serve as many as 10 or 12 classrooms depending on the building's inner materials and layout. Testing is the key.
Usually, a vendor or network provider can demonstrate or test a wireless device at your location. If you have this testing done, be sure to go into it with an open mind and an eye toward saving time and money as well as gaining flexibility.
Wireless PC connections are also an excellent way to connect laptop computers to a network. A PCMCIA card for a laptop computer costs somewhat less than a desktop wireless card. Such a card would be useful for connecting laptops used in a portable lab and could easily move room to room up to 300 feet from the receiver. For Internet demonstrations and laboratory testing, desktop computers set on computer carts would also benefit from this wireless configuration.
Wireless LANs now present an effective and, in many cases, cheaper, more flexible alternative to wiring with Cat 5 cables. In the near future, this type of networking will become even more affordable. An increase in the number of devices manufactured almost always brings up competition and decreases prices.
Home wireless systems are also available. These prevent the need to drill holes in your floor, and your kids can change the location of their computers. They can even bring their laptop to the dinner table! Sure, just what you needed.
If you have any trouble with network testing at your location, let me know via email. I can usually get a vendor to demonstrate at any school site.
Email: Tom Hashem
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