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Wireless Computer
Networking:
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| Introduction | Information Links | Vendor Links | Discussion |
Introduction
As school districts struggle with how to interconnect local area networks (LANs) that they have in operation at various campuses to form a wide area network (WAN), one viable solution that is not well known is the use of wireless technology. Wireless network bridges, using spread spectrum radio waves or microwaves, can be used to connect LANs that are separated by as much as 25 miles. Many of the less powerful bridges, however, may be limited to a range of 2-5 miles.
These wireless links can provide data transfer rates from less than 1 Mbps to more than 10 Mbps. As one might expect, the greater the link distance capability, and the higher the data transfer rate, the more expensive is the equipment. For example, a pair of bridges operating at a radio frequency of 900 MHz may cost $6000, provide a link distance of 1.0-2.0 miles, and transfer data at 1 Mbps.
A 2.4 Ghz bridge might cost approximately $5000, provide a reliable link over a distance of 3-6 miles, and transfer data at 2 Mbps.
A microwave link at 31 Ghz may provide a connection over 7-10 miles at 10Mbps (full duplex) for a cost of less than $30000 for the equipment.
One really attractive feature of wireless connections, and their major advantage, is that there is a one-time cost for the equipment and installation. There are no recurring, on-going monthly costs! Thus, when compared to connection options that have continuing monthly fees associated, the wireless solution quickly pays for itself.
The potential drawbacks to a wireless solution include environmental factors. The terrain may eliminate wireless as an option. Intervening hills and tall buildings or trees can block the radio frequency (RF) signals. Wireless RF technology is referred to as "line-of-sight". This means that the antennas on the wireless bridge units must be able to "see" each other; there must be no obstacles in the way to block or reflect the transmitted signals.
Severe weather, such as torrential rains, can adversely affect signal transmission and temporarily down the link. Similarly, the link might be susceptible to other radio frequency interference. Dense fog could possibly be a problem for microwave links.
The bottom line: wireless connectivity must be seriously considered if the terrain allows its use. Some reports indicate that microwave links can be more reliable than leased data lines. Below are links to other information concerning wireless computer networking. The first link is to a site which reports on a National Science Foundation project designed to demonstrate the usefulness of wireless networking technology in education.
| Introduction | Information Links | Vendor Links | Discussion |
| Introduction | Information Links | Vendor Links | Discussion |
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Texas Center for Educational Technology
If you are aware of additional sites that would be of interest, contact tcet@unt.edu