What’s in a (WiFi) word?

WifiWords

If I need a new WiFi access point, should I get an 802.11n access point, one that follows 802.11 Clause 20 access point, or an HT access point.? Why not get them all?  That’s easy enough you see because they are all the same!

Let’s look at how this whole mess began.  The IEEE created the 802 family of standards in 1980.  You probably recognize 802.3 as Ethernet and maybe even 802.5 for Token Ring if you’ve been around like me.  The IEEE specifications that I deal with on a daily basis are 802.11 (WLAN) and 802.15 (WPAN).  Way back in 1997 the original 802.11 standard was born and soon followed by 802.11a and b in 1999.  802.11g was born in 2003 which used the same modulation as 802.11a and ported it to 5.0GHz.

By the time 2007 came around the IEEE decided to reboot the standard to 802.11-2007 by rolling up all the amendments (a,b,d,e,g,h,i,j) into this one.  The clauses are a little confusing and to make matters worse they changed in 2012 after a subsequent roll up.

Here are all the amendments (from Wikipedia) up until 2012…

  • IEEE 802.11-1997: The WLAN standard was originally 1 Mbit/s and 2 Mbit/s, 2.4 GHz RF and infrared (IR) standard (1997), all the others listed below are Amendments to this standard, except for Recommended Practices 802.11F and 802.11T.

  • IEEE 802.11a: 54 Mbit/s, 5 GHz standard (1999, shipping products in 2001)

  • IEEE 802.11b: Enhancements to 802.11 to support 5.5 Mbit/s and 11 Mbit/s (1999)

  • IEEE 802.11c: Bridge operation procedures; included in the IEEE 802.1D standard (2001)

  • IEEE 802.11d: International (country-to-country) roaming extensions (2001)

  • IEEE 802.11e: Enhancements: QoS, including packet bursting (2005)

  • IEEE 802.11F: Inter-Access Point Protocol (2003) Withdrawn February 2006

  • IEEE 802.11g: 54 Mbit/s, 2.4 GHz standard (backwards compatible with b) (2003)

  • IEEE 802.11h: Spectrum Managed 802.11a (5 GHz) for European compatibility (2004)

  • IEEE 802.11i: Enhanced security (2004)

  • IEEE 802.11j: Extensions for Japan (2004)

  • IEEE 802.11-2007: A new release of the standard that includes amendments a, b, d, e, g, h, i, and j. (July 2007)

  • IEEE 802.11k: Radio resource measurement enhancements (2008)

  • IEEE 802.11n: Higher-throughput improvements using MIMO (multiple-input, multiple-output antennas) (September 2009)

  • IEEE 802.11p: WAVE—Wireless Access for the Vehicular Environment (such as ambulances and passenger cars) (July 2010)

  • IEEE 802.11r: Fast BSS transition (FT) (2008)

  • IEEE 802.11s: Mesh Networking, Extended Service Set (ESS) (July 2011)

  • IEEE 802.11T: Wireless Performance Prediction (WPP)—test methods and metrics Recommendation cancelled

  • IEEE 802.11u: Improvements related to HotSpots and 3rd-party authorization of clients, e.g., cellular network offload (February 2011)

  • IEEE 802.11v: Wireless network management (February 2011)

  • IEEE 802.11w: Protected Management Frames (September 2009)

  • IEEE 802.11y: 3650–3700 MHz Operation in the U.S. (2008)

  • IEEE 802.11z: Extensions to Direct Link Setup (DLS) (September 2010)

  • IEEE 802.11-2012: A new release of the standard that includes amendments k, n, p, r, s, u, v, w, y, and z (March 2012)

Here is a handy little translator that explains further changes in the clauses from 2007 to 2012:

clauses

 

So that explains some things that are usually a little cloudy.  IEEE specs are not the only area in the wireless arena that can be confusing.  People’s definitions of Guest and BYOD often vary.  My understanding is that Guest is usually a specific type of BYOD, whereas BYOD implies that the user is an employee but owns their own mobile device.

byod_spectrum

Remember that networking is very technical stuff and knowing terms and what acronyms stand for can be half the battle.  I will spare you all the discussion on MPDU versus PSDU, I guess that will be a future blog.

 

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