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Infrared (IR) systems use very high frequencies, just below visible light in the electromagnetic spectrum, to carry data. Like light, IR cannot penetrate opaque objects; it is either directed (line-of-sight) or diffused technology. Inexpensive directed systems provide very limited range, approximately 3 feet, and typically are used for personal area networks but occasionally are used in specific wireless LAN applications. High performance directed IR is impractical for mobile users and is therefore used only to implement fixed sub-networks. Diffused (or reflective) IR wireless LAN systems do not require line-of-sight, but cells are limited to individual rooms.
Infrared technology can be used in school to link students' laptop computers to the school's network. One or more unobtrusive Ceiling Access Points (CAPs) are mounted into the ceiling of every classroom and other places.
When students enter a classroom and open up their computers, they are immediately connected to the school's network. Students are allowed access the Internet, email, the local classroom printer, and files and programs that reside on the school server.
This high-speed connection takes place without the wire and cable clutter often found in school computer labs and classrooms. The students' computers operate on internal batteries, so there are no tangled nests of power cords. The CAPs and the IR technology allow students to sit anywhere, face in any direction and still remain connected to the server.
Click HERE to find out more about how wireless LANs are configured
Infrared in Other Devices
IR has been around a long time and is utilized in devices that you see and use every day: TV remote controls and home security systems. This technology has also become a favorite of networking executives who use their handheld PDAs to exchange messages and electronic business cards at meetings and conferences.
For other examples of uses in real life click HERE
Researchers at Pennsylvania State university are in the process of developing a high-speed network using infrared and say that it could be faster, more efficient than the current system.
Dr. Mohsen Kavehrad and Svetla Jivkova are experimenting with infrared light that bounces off myriad surfaces in a room, which they say is capable of transmitting data at two gigabits per seconds, which is roughly 1,000 times faster than cable modems, and with fewer errors.
Another exciting IR technology close to approval is Infrared Financial Messaging (IrFM). This protocol allows users to write "checks" on handheld PDAs and beam encrypted "money" to point-of-sale terminals. The electronic purchase information can later be transferred to the user's PC to update financial management software. Credit card companies are working to approve a similar electronic payment system.