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What is 802.11a/b/c/d/e..../z ? And how about CCX?

 

 

Introduction

 

 

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.

 

 

Standard/draft name Description Obsoleted by
802.11 Original standard defining 1 and 2Mbps 2.4Ghz RF and IR. All the  followings are amendments to this standard included in revisions 802.11-2007
802.11a This standard defines OFDM 54Mbps operation in the 5Ghz band 802.11-99
802.11b Enhancements to 802.11 to support 5,5 and 11Mbps in the 2.4Ghz band 802.11-99
802.11c Defines bridging operations for 802.11 . It has been included in 802.1D as a chapter concerning wireless bridging 802.1D
802.11d International roaming extensions. Adds a country field in beacons  and other frames. Add countries not defined by original standard. 802.11-2001
802.11e QoS features.WMM is actually a subset of 802.11e. 802.11-2007
802.11F Set of recommendations (optional) defining Inter-Acces Point  Protocol (IAPP) for exchanging client security context between APs. This  amendment has been withdrawn in 2006. 802.11-2003
802.11g Defines ERP-OFDM modulation in 2.4Ghz enabling 54Mbps with backward compatibility with 802.11b 802.11-2003
802.11h 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 802.11-2007
802.11i WPA was an early subset of 802.11i where WPA2 is the full 802.11i  implementation. It defines RSNs, AES and TKIP encryptions, … 802.11-2007
802.11j (2004) Amendment specific to Japan allowing for example use in 4.9Ghz band 802.11-2007
802.11-2007 Currently latest revision of the standard including amendments for 802.11a to 802.11j (except for .11c and .11F)
802.11k Proposed amendment to define radio management. It will facilitate  roaming in an ESS by helping chosing the best access point available  (load balancing)
802.11l Reserved and will not be used
802.11m .11m is an ongoing taskgroup charged of the maintenance of the  standard. It periodically produces the revisions, brings clarifications  and modifications
802.11n Amendment unleashing high speeds, MIMO, 40Mhz channels and lots of other features
802.11o Reserved and will not be used
802.11p 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)
802.11q Not used to avoid confusion with 802.1q vlan trunking
802.11r 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
802.11s This amendment will standardize mesh networks
802.11T This amendment regroups recommended practices to test and measure  performance in wireless networks. . Also called WPP, Wireless  Performance Prediction
802.11u 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
802.11v This amendment will bring the possibility to configure clients while they are connected to the network
802.11w This amendment will bring Protected Management Frames. It is  supposed to be an add-on to 802.11i covering management frames security
802.11x Not used to avoid confusion with 802.1x
802.11y Allows operation in the 3650 to 3700 MHz band (licensed) allowing for higher powers and thus ranges.
802.11z 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.

 

 

Wi-FI Alliance

 

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.

 

LWAPP standard

 

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.

 

Reference - A word about CCX

 

CCX : Cisco Compatible Extensions ? Never heard about it

 

Cool but which devices support CCX ?

 

Great but what feature is in what CCX version ?