Rather than connecting to a specific location, the user is able to move around within the covered area and maintain their connection. Each of the connections between one of these transmitting antennas and the receiving customers is called a backhaul and is analogous to the "last mile" connection between the ISP and the customer's home or office.
| The ultimate expression of being able to access the Internet from anywhere is the 802.20 standard; Global Area Network (GAN). This would work more like cell phones that can send and receive via a satellite network from anywhere in the world. |
WiMAX can handle data transfer rates of up to 70 Mbps however, like a standard cable connection; the bandwidth is shared among all of the users on that radio backhaul. The result will still allow users an average speed comparable to a wired broadband connection over a radius of about 50 kilometers. Any computer that needs to connect to a WiMAX network would have to be fitted with the appropriate hardware including a WiMAX compliant network interface card and antenna. WMAN networks are offered for free in certain cities and offered as a paid service elsewhere. Implementations include the home and business user as well as mobile users.
If you were a construction foreman and supervised several sites across a city, you would be able to use your laptop to consult with materials vendors via email or Instant Messenger or do research on the web from anywhere you were working. Data transfers between you and your company's central file server would not have to wait until you were in proximity to a WPAN or you established a connection between the laptop and the company's LAN back at the office.
Shedding Light on Infrared (IR)
Infrared-based wireless networking deserves an honorable mention but you are unlikely to find a WLAN using infrared light as a carrier medium. The original 802.11 standard for 1 to 2 mbps data transfers does include Infrared (IR) as well as Radio Frequency (RF) technologies. While radio waves connect devices in different rooms of a house or office suite by traveling through walls, IR signals bounce off of walls and like a billiard ball, ricocheting from room to room.
This type of wireless solution has its fair share of advantages and disadvantages. Unlike RF signals, IR transmissions cannot escape the outer walls of your home or office to be detected (and perhaps read) by an unauthorized person (even a closed door will stop IR). This means that you have more security for your IR network than a radio-based WLAN. You also need not be concerned with signal interference since even if a neighboring office was also using IR, the signals would never interact.