Wireless Area Networks
Wireless technology has become an increasingly crucial part of today's world. From health care and retail to academia across the world, wireless systems are improving the rate and ease with which data is sent and received. Two specific examples of the wireless technology used today personally and professionally are local area networks (LAN) and personal area networks (PAN).
A wireless local area network, or LAN is a flexible data communications system implemented as an augmentation to, or an alternative for a, wired local area network. These networks rely on electromagnetic airwaves to transmit and receive over a defined area, usually a few hundred feet. (Yahoo-wireless) In most cases, a wireless transmitter will be connected directly to a wired land network using Ethernet cables. Once the network feed has been connected to the transmitter, and a constant power supply is established, a steady stream of radio, or infrared waves with be produced (both are electromagnetic waves). The vast majority of wireless LAN systems tend to rely on radio waves as the carries for their signals, because infrared waves tend to have a shorter distance at which they are able to transmit, and are more easily interrupted. Radio waves, or radio carriers as they are referred to, transfer data through modulations of the carrier signal. The addition of data to a radio carrier causes the signal to occupy more than a single frequency. Once data is imprinted onto the radio signal it is a simple reversal of the transmitting process that allows the information to be decoded by a receiving station. (Rho Wireless)
Radio waves offer another benefit to the wireless system in addition to their range. With radio signals it is possible for multiple carriers to exist in the same space at the same time without interfering with each other. The key to making this possible is variation of frequencies. As long as concurrent frequencies are no being broadcasted in a given area, it is possible to have any number of radio transmissions taking place at a given time. One might ask with countless number of transmissions that could be occurring at a given time how is it possible to focus on just one stream of data? The answer again is achieved through radio frequency characteristics. Once data has been encoded into a given radio carrier, all one has to do to extract the information is have a receiver tuned into one specific frequency, while rejecting all others. These receiving and transmitting nodes are known as access points. In typical wireless LAN settings, these access points are in the form of small rectangular transmitting stations. Receiving access points, or LAN adapters, defined using 802.11EE coding, are implemented as PC cards in notebooks, palm pilots, and desktops, or as additional access points that serve to extend the area of the network. These adapters provide an...