How Does
How Does a Laptop With Wireless Internet Work?
WLAN
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Wireless Internet access, abbreviated properly as WLAN or generally as Wi-Fi, enables users to unplug their laptops from cable modems and access the Internet anywhere a wireless Internet signal can be intercepted. This can occur in a private setting by connecting a wireless router to a cable modem, which boosts the signal into the surrounding area, or by peer-to-peer networks and at public wireless "hotspots," such as those offered by hotels, airports and cafes. All of these are called wireless access points.
Modulation Techniques
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WLAN uses one of two technologies--spread-spectrum or OFDM (orthogonal frequency-division multiplexing)--in order to spread out wireless signals via radio waves. Accomplished through either direct use of one frequency or by "frequency hopping," both technologies allow multiple users to use the same source to access the Internet, with spread-spectrum using one signal and OFDM using a combination of signals. For more on modulation techniques, see Resources below.
Intercepting a Wireless Signal
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Laptops intercept wireless signals via a wireless network interface card (NIC), which now is a standard internal component of new laptops. The NIC is equipped with a small antenna to receive and send signal over the LAN, as opposed to an Ethernet port which would otherwise directly connect the computer to a wired network. (By altering settings, laptops can work either wired or wirelessly.)
Repeating and Reflecting
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One concern with wireless networking is that the signal can be blocked relatively easily by distance and by architectural and sometimes natural features. This can be overcome by using more access points and technologies variously referred to as bridges, repeaters and reflectors, all designed to help wireless signals overcome these barriers (see Resources).
eHow Article: How Does a Laptop With Wireless Internet Work?
