Wi-Fi/802.11 standards

Wi-Fi and 802.11 refer to wireless networks -- also known as WANs (Wireless Area Networks) and LAWNs (Local-Area Wireless Network).  These are local-area networks that use high-frequency radio waves rather than wires to communicate between nodes.  Here at the medical campus, the wireless network is an extension of and complement to the wired network.

Wi-Fi (pronounced "Why-Fye") stands for "Wireless Fidelity."  The Wi-Fi name was created as an analogy to "Hi-Fi" (High Fidelity) for audio.  The medical campus wireless network supports 802.11b, 802.11g or combination 802.11b/g wireless adapters.  These are sometimes called "11b", "54g" or "wireless G" adapters.  More about those suffixes below.

Wi-Fi should not be confused with Bluetooth, a wireless protocol for short-range communications between devices like computers and printers, or telephones and headsets.

Flavors of 802.11

802.11 is a family of technical specifications developed by the Institute of Electrical and Electronics Engineers (IEEE) for wireless networking.  Standards in the 802.11 family specify an over-the-air interface between a wireless client (like a laptop) and a base station transceiver, or between two wireless clients in a peer-to-peer relationship. The IEEE accepted the specification in 1997.

The 802.11 standards, which are differentiated by an alphabetic suffix, include:

802.11 -- The basic standard applies to wireless LANs and provides 1 or 2 Mbps transmission in the 2.4 GHz band (the same one used by many cordless phones).  It uses either frequency hopping spread spectrum (FHSS) or direct sequence spread spectrum (DSSS) modulation.

802.11a -- an extension to 802.11 that applies to wireless LANs and provides up to 54 Mbps in the 5 GHz band.   Standard 802.11a uses orthogonal frequency division multiplexing (OFDM).  The Medical Center wireless cloud can support 802.11a as required but only in limited areas if there are frequency or channel overlap issues that must be resolved.

802.11b -- also referred to as 802.11 High Rate or Wi-Fi, is an extension to 802.11 that applies to wireless LANs and provides 11 Mbps transmission (with a fallback to 5.5, 2 and 1 Mbps) in the 2.4 GHz band.  Standard 802.11b uses only DSSS.   Standard 802.11b was a 1999 ratification to the original 802.11 standard, allowing wireless functionality comparable to Ethernet.  The Medical Center wireless cloud supports 802.11b radio cards.

802.11g -- applies to wireless LANs and provides 20+ Mbps in the 2.4 GHz band.  The Medical Center wireless cloud also supports 802.11g radio cards.

Other standards in the 802.11 family, which employ practically the entire alphabet for differentiation, include 802.11e (quality of service), 802.11i (enhanced security), and 802.11n (throughput enhancements).

Other terminology

A wireless network is established by deploying groups of radio transceivers -- known as wireless access points (WAPs).   The coverage area of the WAPs established the boundaries of what is commonly referred to as the "wireless cloud."   You can see the current Medical campus wireless cloud here.

Wireless signals can be intercepted by any device within the cloud.  This is convenient for mobile users, but it also presents a security problem.   Accordingly, the 802.11 standards include encryption in order to protect transmissions.  Two commonly-used encryption protocols are WEP (Wireless Equivalent Privacy) and WPA (Wi-Fi Protected Access). 

Wireless networks can be named -- formally, given an SSID (Service Set IDentifier).   This is the "network name" that appears when your computer encounters a wireless signal.

Learn more

802.11 (IEEE)
Official site of the IEEE 802.11 working group

802.11 (Wikipedia)
Overview and links to a range of information on the standards family