WIFI OR WIRELESS

WiFi is the wireless way to handle networking. It is also known as 802.11 networking and wireless networking. The big advantage of WiFi is its simplicity. You can connect computers anywhere in your home or office without the need for wires. The computers connect to the network using radio signals, and computers can be up to 100 feet or so apart.

In this article, we will discuss two different aspects of WiFi. First we will discuss the basic technology that makes WiFi networking possible. Then we will discuss the hardware you need to create a WiFi network, and help you understand how to set up and access a WiFi hotspot in your home.

• WiFi radios that work with the 802.11b and 802.11g standards transmit at 2.4 GHz, while those that comply with the 802.11a standard transmit at 5 GHz. Normal walkie-talkies normally operate at 49 MHz. The higher frequency allows higher data rates.

• WiFi radios use much more efficient coding techniques that also contribute to the much higher data rates. For 802.11a and 802.11g, the technique is known as orthogonal frequency-division multiplexing (OFDM). For 802.11b, it is called Complementary Code Keying (CCK).

• The radios used for WiFi have the ability to change frequencies. 802.11b cards can transmit directly on any of three bands, or they can split the available radio bandwidth into dozens of channels and frequency hop rapidly between them. The advantage of frequency hopping is that it is much more immune to interference and can allow dozens of WiFi cards to talk simultaneously without interfering with each other.

Because they are transmitting at much higher frequencies than a Walkie-Talkie, and because of the encoding techniques, WiFi radios can handle a lot more data per second. 802.11b can handle up to 11 megabits per second (although 7 megabits per second is more typical, and 802.11b may fall back as low as 1 or 2 megabits per second if there is a lot of interference). 802.11a and 802.11g can handle up to 54 megabits per second (although 30 megabits per second is more typical).

You might be wondering where the funny 802.11 nomenclature comes from. The Institute of Electrical and Electronics Engineers (IEEE) creates standards, and they number these standards in unique ways. The 802.11 standard covers wireless networks. The a, b and g notations identify different flavors of the 802.11 standard:

• 802.11b was the first version to reach the marketplace. It is the slowest and least expensive of the three. As mentioned above, 802.11b transmits at 2.4 GHz and can handle up to 11 megabits per second.

• 802.11a was next. It operates at 5 GHz and can handle up to 54 megabits per second.

• 802.11g is a mix of both worlds. It operates at 2.4Ghz (giving it the cost advantage of 802.11b) but it has the 54 megabits per second speed of 802.11a.

Fortunately, all of this radio technology is hidden in a WiFi card and is completely invisible. WiFi, in fact, is one of the easiest technologies that you will ever use.

• WiFi radios that work with the 802.11b and 802.11g standards transmit at 2.4 GHz, while those that comply with the 802.11a standard transmit at 5 GHz. Normal walkie-talkies normally operate at 49 MHz. The higher frequency allows higher data rates.

• WiFi radios use much more efficient coding techniques that also contribute to the much higher data rates. For 802.11a and 802.11g, the technique is known as orthogonal frequency-division multiplexing (OFDM). For 802.11b, it is called Complementary Code Keying (CCK).

• The radios used for WiFi have the ability to change frequencies. 802.11b cards can transmit directly on any of three bands, or they can split the available radio bandwidth into dozens of channels and frequency hop rapidly between them. The advantage of frequency hopping is that it is much more immune to interference and can allow dozens of WiFi cards to talk simultaneously without interfering with each other.

Adding WiFi to a Computer
One of the best things about WiFi is how simple it is. Many new laptops already come with a WiFi card built in -- in many cases you don't have to do anything to start using WiFi. It is also easy to add a WiFi card to an older laptop or a desktop PC. Here's what you do:

• Buy a 802.11a, 802.11b or 802.11g network card. 802.11g has the advantage of higher speeds and good interoperability on 802.11b equipment.

  • For a laptop, this card will normally be a PCMCIA card that you slide into a PCMCIA slot on your laptop. Or you can buy a small external adapter and plug it into a USB port.

  • For a desktop machine, you can buy a PCI card that you install inside the machine, or a small external adapter that you connect to the computer with a USB cable.

• Install the card

• Install the drivers for the card

• Find an 802.11 hotspot

• Access the hotspot.

A hotspot is a connection point for a WiFi network. It is a small box that is hardwired into the Internet. The box contains an 802.11 radio that can simultaneously talk to up to 100 or so 802.11 cards. There are many WiFi hotspots now available in public places like restaurants, hotels, libraries and airports. You can also create your own hotspot in your home..