What is Wi-Fi?

Wi-Fi (Wireless Fidelity) lets you connect to the Internet wirelessly if your Mac is equipped with a wireless AirPort card and if you're within range of a wireless base station that's sending out a wireless Internet signal. Most wireless networks todaythose found in homes, cafes, and hotelsare meant to cover small areas and are known as WLANs (Wireless Local Area Networks).

Geeky Techno Stuff

Wi-Fi technology is based on the IEEE (Institute of Electrical and Electronics Engineers) 802.11 family of wireless network standards created by the Wi-Fi Alliance, an independent organization that tests and certifies Wi-Fi products, and is responsible for promoting Wi-Fi technology.

The newer 802.11 g standard is backwards-compatible with older 802.11 b hardware.

Wi-Fi includes several versions of the 802.11 standards, with new versions being developed for the very near future. Currently the two most common are 802.11 b (the first AirPort Base Stations and AirPort cards use this version) and 802.11 g, which is advertised as five times faster than 802.11 b.

When you see wireless cards or modems advertised with specific Internet speeds, keep in mind that these are always optimum theoretical speeds. Your actual speed of downloading or uploading will be substantially slower due to something called "network overhead." The diagram below shows some typical Internet connections and their advertised speeds.

Broadband speeds start around 500 kbps (kilobits per second), which is fast enough to listen to streaming music or watch streaming video. As you can see below, both versions of Wi-Fi are well within the range of broadband, even considering their actual speeds instead of their theoretical speeds.

The typical lineofsight range for a current Wi-Fi network (b or g) is around 300 feet, depending on interference issues such as nearby buildings or thick walls (here in New Mexico, threefoot walls are not uncommon). Other versions of Wi-Fi are on the way that promise increased speed and range. See the next page for a glimpse of the Wi-Fi future.

Typical Internet connection types and speeds.

Wireless Internet Technologies

There are wireless Internet technologies that exist besides Wi-Fi, and more that are being developed. One you may be able to take advantage of right now is EVDO; see Chapter 11. Below are more details about Wi-Fi and WiMAX.

• 802.11b (11 Mbps) and 802.11g (54 Mbps). Besides these two standards, there are several other versions lurking just around the corner that will enhance our mobile computing experiences. Of course, when these technologies are available, you'll need to install a compatible wireless card to take advantage of them. Wireless technology is also an example of the "format wars" we've seen in video and DVD formats. It remains to be seen which technologies will be bigtime and longterm players.

• 802.11n. This standard is expected to be approved in early 2007 or sooner. Described as the next generation of 802.11 standards, 802.11n uses multiple wireless antennas to transmit and receive data, and claims speeds in excess of 100 Mbps. The range is expected to be greater than existing Wi-Fi.

  Products called "Pren" (such as wireless modems and routers) are already on the market, claiming throughput speeds that are impressive. There's no guarantee that Pren products will be compatible with the final 802.11n specifications.

• WiMAX (802.16). This standard is designed for wireless metropolitan area networks (man). While it's too technical and expensive for average home users, it's a promising solution for providing wireless access to entire neighborhoods or cities. Wimax proponents claim a range of up to 30 miles in areas where there's an unobstructed line of sight, and 3 to 5 miles in city areas where buildings cause interference. Speeds of 75 Mbps are also claimed, but these are theoretical numbers. The latest market research predictions say Wimax will be widely available after 2009.

Many other wireless standards being developed, but these are the ones you're most likely to hear about in the near future. Good ol' Wi-Fi (802.11 standards) will remain popular, mainly because its price tag is likely to stay far below the others.

If you want to stay informed on the latest wireless technologies and products, check some of the web sites devoted to just thatsearch the web for "Wi-Fi news." One good source for great wireless information, news, product reviews, and tips is the JiWire weeklywire newsletter. At JiWire.com you can register for a free JiWire membership that includes the email newsletter.