This page first presents a table containing short descriptions for each 802.11 task groups and follows with some words about the different wireless certifications and their content.
Original standard defining 1 and 2Mbps 2.4Ghz RF and IR. All the followings are amendments to this standard included in revisions
This standard defines OFDM 54Mbps operation in the 5Ghz band
Enhancements to 802.11 to support 5,5 and 11Mbps in the 2.4Ghz band
Defines bridging operations for 802.11 . It has been included in 802.1D as a chapter concerning wireless bridging
International roaming extensions. Adds a country field in beacons and other frames. Add countries not defined by original standard.
QoS features.WMM is actually a subset of 802.11e.
Set of recommendations (optional) defining Inter-Acces Point Protocol (IAPP) for exchanging client security context between APs. This amendment has been withdrawn in 2006.
Defines ERP-OFDM modulation in 2.4Ghz enabling 54Mbps with backward compatibility with 802.11b
Amendment for Spectrum and Transmit Power Management. It adds Dynamic Frequency Selection (DFS) to avoid radars in the 5Ghz band as well as Transmit Power Control (TPC) to the 802.11a
WPA was an early subset of 802.11i where WPA2 is the full 802.11i implementation. It defines RSNs, AES and TKIP encryptions, …
Amendment specific to Japan allowing for example use in 4.9Ghz band
Currently latest revision of the standard including amendments for 802.11a to 802.11j (except for .11c and .11F)
Proposed amendment to define radio management. It will facilitate roaming in an ESS by helping chosing the best access point available (load balancing)
Reserved and will not be used
.11m is an ongoing taskgroup charged of the maintenance of the standard. It periodically produces the revisions, brings clarifications and modifications
Amendment unleashing high speeds, MIMO, 40Mhz channels and lots of other features
Reserved and will not be used
Defines WAVE (Wireless Access for Vehicular Environment such as ambulances or other high speed vehicles and roadside infrastructure in the licensed band of 5.9Ghz)
Not used to avoid confusion with 802.1q vlan trunking
This amendment is charged to ensure fast roaming even for vehicles in motion. It is supposed to bring the roaming delay between 2 BSS under 50ms
This amendment will standardize mesh networks
This amendment regroups recommended practices to test and measure performance in wireless networks. . Also called WPP, Wireless Performance Prediction
Proposed amendment to improve internetworking with external non 802.11 networks. The idea is to be able to specify services provided by a BSS, to allow access to the BSS depending on previous authentication with other networks and also restrict access to the BSS
This amendment will bring the possibility to configure clients while they are connected to the network
This amendment will bring Protected Management Frames. It is supposed to be an add-on to 802.11i covering management frames security
Not used to avoid confusion with 802.1x
Allows operation in the 3650 to 3700 MHz band (licensed) allowing for higher powers and thus ranges.
Direct Link Setup (DLS) allows two stations to discuss directly between each other
Note : when the amendment letter is capital as in 802.11F, this means that it is not mandatory part of the standard but rather recommended practices.
The Wi-Fi alliance is a vendor-neutral association founded by Cisco amongst others. Its goal is to certify group of features to be compatible between vendors. They usually take a subset of a 802.11 standard(s). Examples of what the alliances certifies : WPA, WPA2, WMM, WMM power save, WMM access control, Voice, Simple Secure Config, pre-11n.
This "over the wire" standard developed by Cisco for controller-based management and provisioning of access points has been the base to the IETF CAPWAP standard that was recently released. Configuration And Provisioning for Wireless Access Points is a standard that basically takes all features of LWAPP and add some taken from other similar protocols.
CCX (Cisco Compatible eXtensions)
This "over the air" series of certifications (different versions of it are available to represent the amount of features supported by the product) is driven by Cisco to certify supports of early drafts/standards. A complete list of features for each CCX version is available on Cisco.com but it is interesting to note that CCX defines points from 802.11k (radio measurement), 802.11r (fast roaming), 802.11u (compatibility with external networks), 802.11v (client management) and 802.11w (management frame security).
Short glance at 802.11k : Radio Measurement
802.11k is mostly included in CCxv2 and updated by CCXv5 and contains features like AP neighbor information (roaming and power saving), rogue detection vie beacons reporting, channel traffic snapshot, channel load, noise histogram, average access delay, location, link quality, transmit stream measurements.
Short glance at 802.11r : Fast Roaming
This is an extension to CCKM. It is destined to establish both security and quality of service parameters when reassociating. The handoff is supposed to stay under 50ms with a goal of 20ms for smart clients. The standard will be based on CCKM.
Short glance at 802.11u : Interworking with outside network
The goal with .11u is to support neutral hostpots : a shared wlan infrastructure provices service to different Service Providers, power efficient scanning for preferred SPs, support for unauthenticated emergency calls, media independent handover (802.21), communication of DSCP to COS mapping to client.
Short glance at 802.11v : client management
Most of these features are in CCXv4 and 5: diagnostics, event logs, multiple BSSIDs, improved client power saving, wake on WLAN.