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Laptop computers have used three basic wireless technologies: infrared, wi-fi and bluetooth. The oldest is infrared, which allows laptops with similar technology to communicate with each other over a short range. The earliest Apple Macintosh Powerbooks in 1996 used infrared, but infrared is used now only in limited applications.
Next came standard wi-fi, which is currently the most common wireless technology. Originally, wi-fi relied on a PCMCIA or PC card that plugged into the PC slot of the laptop. It came with appropriate software for the PC or used software that was built-in on the Mac. Later, laptops became available with built-in wi-fi hardware and software. Wi-fi allows a laptop to communicate with wireless routers connected to a hard-line modem.
The third wireless technology is bluetooth. This connects the laptop with devices such as wireless keyboards, mice, printers and other computers. - Wi-fi works with radio waves--the same as a radio, intercom, wireless phone or walkie-talkie. The card in the laptop, whether a plug-in PCMCIA card or an internal card, turns the computer's signals into radio waves and sends it to the wireless router. The router picks up the signal, turns it back into traditional computer communications, and outputs it to the hard-line ethernet. The process is reversed to get the signal back to the laptop. A wi-fi card can use any of several protocols: 802.11b, 802.11g and 802.11n. The last of these transfers data the fastest.
- Bluetooth is a more precise means of wireless communication because it has a set frequency that transmits and receives in the same manner on every enabled device. It is set at 2.45 GHz and transmits a low signal so as not to get mixed up with other wireless devices such as cell phones. When first connecting a bluetooth device to a laptop, you must have the laptop's bluetooth search for the kind of device you want to connect, such as a mouse or keyboard. The laptop then creates a remembered connection protocol for each device, allowing you to use several devices at once, such as a mouse, keyboard and printer, without the signals mixing.
