802.11 Alphabet SoupBy CWNP On 10/14/2010 - 19 Comments
Have you ever tried to recite all 802.11 amendments from 802.11-1997 to today's working drafts? Ever wonder what happened to the lost letters of the 802.11 spec like 802.11o? Let’s review, shall we?
Note that I use intentional language throughout this list, as follows:
“Defined” means the amendment either no longer exists or it was rolled into the existing (or prior versions) 802.11-2007 spec. “Defines” means it is a ratified amendment that will be rolled into 802.11-2011. “Will define” means it is a work in progress and not yet amended.
802.11-1997 (sometimes called 802.11 “prime”) — the original 802.11 specification included the base functionality along with FHSS and DSSS PHYs.
802.11a — Defined OFDM usage in 5 GHz with data rates up to 54 Mbps.
802.11b —Defined 5.5 and 11 Mbps with HR/DSSS in 2.4 GHz.
802.11c — Defined MAC bridging for 802.11. Was incorporated into 802.1D.
802.11-1999 rolled up 802.11 prime with new enhancements.
802.11d — Defined 802.11 operation in new regulatory domains.
802.11e — Defined QoS
802.11F — Recommended Inter-Access Point Protocol (IAPP) for interoperability of different vendor products. Was not used by anyone and is now withdrawn.
Note: A capital letter designates a
recommended practice standalone standard (similar to 802.1X). A lowercase letter designates an amendment to a parent standard. Hence, 802.11F was designed to be a standalone document (and also happened to be a recommended practice), not a part of the full 802.11 standard. This is often a confusing topic in standards naming.
802.11g — Defined ERP PHY, which introduces data rates up to 54 Mbps in 2.4 GHz.
802.11-R2003 rolled up 802.11-1999 and prior amendments, excluding 802.11e.
802.11h — Defined Dynamic Frequency Selection (DFS) for radar detection and avoidance in some 5 GHz bands. Also defined Transmit Power Control (TPC) for managing client transmit power.
802.11i — Defined security enhancements including TKIP, CCMP, and use of 802.1X with WLANs.
802.11j — Defined 4.9 - 5 GHz operation in Japan.
802.11-2007 rolled up 802.11-R2003 with prior amendments.
802.11k — Defines radio resource management processes for RF data collection and sharing.
802.11l — Due to potential confusion between an “l” (letter) and “1” (number), 802.11l was bypassed.
802.11m — Was used as a maintenance amendment that updated inaccuracies, omissions, and ambiguities.
802.11n — Defines High Throughput (HT) PHY with MCS rates up to 600 Mbps in 2.4 GHz and 5 GHz.
802.11o — For similar reasons as 802.11l, 802.11o was bypassed. ‘Is that an “o” (letter) or a “0” (number)? I don’t know, let’s just skip it.’
802.11p — Defines wireless access for the vehicular environment (WAVE).
802.11q — Due to potential confusion with 802.1Q, 802.11q was bypassed.
802.11r — Defines fast BSS transitions (fast secure roaming). Maybe one of these days we’ll use it.
802.11s — Will define 802.11 mesh internetworking.
802.11T — Specified a way to test wireless performance prediction. Remember, capital letters are
recommended practices standalone standards. 802.11T was cancelled.
802.11u — Will define internetworking with external networks, such as cellular.
802.11v — Will define enhancements for network management.
802.11w — Defines protected management frames to prevent some security vulnerabilities.
802.11x — 802.11 technologies as a whole are often referred to as 802.11x, so this amendment was bypassed.
802.11y — Defines use of OFDM in 3650-3700 MHz.
802.11z —Defines enhancements to Direct Link Setup, which no one uses.
We’re out of letters, whatever will we do?
802.11aa — Will define enhancements to video transport streams.
802.11ab —Was bypassed to avoid confusion with devices using 802.11a and 802.11b PHY technologies, which are often abbreviated as 802.11ab.
802.11ac — Will define Very High Throughput (VHT) with gigabit speeds, building on 802.11n MIMO technology.
802.11ad — Will define short range Very High Throughput (VHT) in the 60 GHz spectrum.
802.11ae — Will define enhancements for QoS management.
802.11af — Will define usage of Wi-Fi in newly opened TV whitespace frequencies.
802.11ag — Similar to 802.11ab, 802.11ag was skipped to avoid confusion with devices using 802.11a and 802.11g PHY technologies, which are often abbreviated as 802.11ag.
802.11ah — Will define usage of Wi-Fi in frequencies below 1 GHz. Also used as an expression of Wi-Fi pleasure. 802.11…ah!
802.11ai — Will define the way artificially intelligent robots overtake the world using Wi-Fi. Actually, that’s a lie. No public info is yet available for 802.11ai.
802.11-2011 is scheduled for mid/late 2011 and will roll up 802.11-2007 with previously ratified amendments.
Wi-Fi has an exciting history. Future amendments hold promise that we’ll continue to push the boundaries nearing the Shannon limit. In the future, we’ll kick old Claude Shannon’s 802.11ass.