Wi-Fi
Wi-Fi (Wifi), or Wireless Fidelity, is freedom: it allows you to connect to the Internet from your couch at home, a bed in a hotel room or a conference room at work without wires. How? Wi-Fi is a wireless technology like a cell phone. Wi-Fi enabled computers send and receive data indoors and out; anywhere within the range of a base station. Wi-Fi networks use radio technologies called IEEE 802.11b or 802.11a to provide secure, reliable, fast wireless connectivity. A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wired networks (which use IEEE 802.3 or Ethernet). Wi-Fi networks operate in the unlicensed 2.4 and 5 GHz radio bands, with an 11 Mbps (802.11b) or 54 Mbps (802.11a) data rate or with products that contain both bands (dual band) and provide network access performance similar to the basic 10BaseT wired Ethernet networks used in offices.
Wi-Fi networks are also found in busy public places like coffee shops, hotels, airport lounges and other locations where large crowds gather. This may be the fastest-growing segment of Wi-Fi service, as more and more travelers and mobile professionals clamor for fast and secure Internet access wherever they are. Soon, Wi-Fi networks will be found in urban areas providing coverage throughout the central city, or even lining major highways, enabling travelers access anywhere they can pull over and stop.
Range or distance covered varies in a Wi-Fi network depending on the type of Wi-Fi radio you have, whether or not you use special antennas, and whether your network is in an open environment or in a building with lots of walls and furniture. The composition of your walls and floors can also have a major impact. Wi-Fi is a very low powered radio signal and does not penetrate metal, water or other dense materials.
Wi-Fi network generally provides a range of about 75 to 150 feet (50 metres) in a typical home or office. In an open environment like an empty warehouse or outdoors, a Wi-Fi network may provide a range of up to 1,000 feet or more. With the right antennas and optimal placement, a range of up to a mile is possible.
With Wi-Fi technology (802.11b or 802.11a), a "gradual degradation" in range occurs. This means that, instead of stopping all together, your data transmission rate just becomes slower as you move farther away from the access point. For example, with Wi-Fi 802.11b technology, within 100 feet of the access point, the Wi-Fi radio in your laptop computer will get about 11 Mbps data rate. As you move farther away, that rate will drop down to 5.5 Mbps, then to 2 Mbps and finally to 1 Mbps.
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Maximum Range |
Range At 11 Mbps |
| Outdoors / open space with standard antenna |
303 metres |
50 -100 metres |
| Office / light industrial setting |
100 metres |
30 - 50 metres |
| Residential setting |
60 metres |
18 - 25 metres | |
Metal and other dense materials can affect the transmission of radio waves. You can expect that your Wi-Fi system will have difficulty transmitting from one room to another if the walls in your home are composed of, or heavily reinforced with, metal. Stone, brick, heavy woods and even water can also affect range.
You can also improve range by turning off or removing electrical appliances that emit interfering radio waves. Some cordless phones , microwave ovens, and radio-operated toy controls operate in the same public 2.4 GHz wireless frequency band as Wi-Fi. You can move the systems farther apart or try to restrict use of interfering devices to times when you're not using your Wi-Fi system. It is also possible to change your Wi-Fi network channel to avoid the channels used by the competing devices. Most Wi-Fi systems use channel 1, 6 or 11 as the default; try switching the channel to 7 or 10.
Connecting the right way: Wi-Fi is more adapted for short range, indoor wireless connections and WiMAX is for long range outdoor connections.
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