.: Advanced Linux Networking :.

Beginning in the late 1990s, wireless networking technologies rose rapidly in popularity. These technologies allow computers to network even without physical cabling connecting them. Such an arrangement is particularly helpful in existing homes and offices in which running conventional wired network cables would be troublesome, and for users of notebook computers and other portable devices, who might want or need to roam about without plugging the computer into a physical network.

Unfortunately, in 2001 the wireless world still suffers from some drawbacks compared to conventional Ethernet networks. Wireless networks are more expensive than are Ethernet networks, they're slower, and they aren't as well standardized. The most important standards for wireless in 2001 are 802.11 and 802.11b. The former supports speeds of 2Mbps, with a fallback to 1Mbps. (Fallback refers to a renegotiation of the connection when signal strength falls, as when there's interference or the computers are far apart from one another.) 802.11b supports speeds of 11Mbps, with fallback speeds of 5.5Mbps, 2Mbps, and 1Mbps. Another wireless technology that's received a lot of press is Bluetooth, which supports speeds of up to 1Mbps. Bluetooth-enabled printers, cell phones, and the like will probably begin shipping in volume in 2002. Future developments are likely to increase available speeds. For instance, plans are underway to develop a wireless version of ATM with speeds of up to 155Mbps.

Wireless LANs are typically implemented through wireless PC Cards in notebook computers. These cards may either communicate directly with one another or may require the use of a base station, which may also serve as an interface to a conventional wired network or to a broadband or conventional telephone modem connection to the Internet. There are also wireless ISA and PCI cards, so that desktop systems can participate in wireless networks, or serve as base stations for roaming devices. PC Cards, ISA cards, and PCI cards all require Linux drivers, but base stations require no special support.

Linux support for wireless devices appears under the Wireless LAN (Non-Hamradio) submenu. This menu lists specific drivers by the chipsets or cards for which they're written, not for the technology (such as 802.11b or Bluetooth) those cards use. In addition to kernel drivers, there are two packages known as the Wireless Extensions and Wireless Tools that help you manage a wireless network under Linux. Check http://www.hpl.hp.com/personal/Jean_Tourrilhes/Linux/Tools.html for information on these packages, and for additional links to information on wireless networking in Linux.