DADDY BOB'S COMPUTER Q & A

December 16, 2007

Q. I notice the wireless standards we use are 802.11b and 802.11g. What happened to all those in between?

A. Well, actually there are many more than just the "b" and "g". Below is the complete current list. Those in the table are the ones that are most familiar. Here is a brief explanation of them.

"a" is rarely used and was originally for businesses. "b" cost less than "a", and was in wide use until "g" was released. "g" is now used by most networks, and is backward compatible with "b". 'n' is scheduled to be released next year and will be compatible with "a", "b" and "g". It will also use 2 channels and 2 antennas.

In the 2.4 GHz range, there are 11 channels which are shared with many other wireless devices. These include cordless phones, cordless keyboards and mouse, and most other home wireless devices. Microwaves also operate in this range and can cause interference. Most home computer wireless networks use channel 6 by default.

All of the many "n" products available now are really preliminary, "Pre-n" products. These are subject to becoming obsolete or needing firmware updates when the standard is finalized.

Actual testing of the Pre-n" products have not yet lived up to its hyped distance or throughput. Also, its needing two of the available channels in the already crowded 2.4 GHz frequency band has caused interferences in congested areas.

"y" should also be released next year, and will cover a much greater distance. It will not be compatible with "a", "b", "g" or "n" and will surely be more expensive than any of the others.

In the table below, note the difference between the typical throughput and maximum rate allowed by each standard.  This leaves considerable room for improvement.

GHz = GigaHurtz  -  Mbps = Megabits per second

One meter = 3.28 feet or 39.37 inches

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IEEE 802.11 - THE WLAN STANDARD was 1 Mbps and 2 Mbps, 2.4 GHz (1997), all others are amendments to this standard, except 802.11a, 802.11F and 802.11T.

IEEE 802.11a - 54 Mbps, 5 GHz standard (2001)

IEEE 802.11b - Enhancements to 802.11 to support 5.5 and
 11 Mbps (1999)

IEEE 802.11c - Bridge operation procedures; included in the IEEE 802.1D standard

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 Mbps, 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 & j. (July 2007)

IEEE 802.11k - Radio resource measurement enhancements
(proposed - 2007?)

IEEE  802.11l - (reserved and will not be used)

IEEE  802.11m - Maintenance of the standard. Recent edits
 became 802.11-2007. (ongoing)

IEEE 802.11n - Higher throughput improvements using MIMO
(multiple input, & output antennas) (September 2008)

IEEE 802.11o - (reserved and will not be used)

IEEE 802.11p - WAVE - Wireless Access for the Vehicular
Environment (such as ambulances and passenger cars) (working - 2009?)

IEEE 802.11q - (reserved and will not be used, can be confused
with 802.1Q VLAN trunking)

IEEE  802.11r - Fast roaming Working "Task Group r" - 2007?

IEEE  802.11s - ESS Extended Service Set Mesh Networking
                       (working - 2008?)

IEEE 802.11T - Wireless Performance Prediction (WPP) - test
methods and metrics Recommendation (working - 2008?)

IEEE 802.11u - Interworking with non-802 networks (for
 example, cellular) (proposal evaluation - ?)

IEEE 802.11v - Wireless network management (early proposal
                       stages - ?)

IEEE 802.11w - Protected Management Frames (early proposal
 stages - 2008?)

IEEE  802.11x - (reserved and will not be used, can be confused
 with 802.1x Network Access Control)

IEEE  802.11y - 3650-3700 MHz Operation in the U.S. (March
                        2008?)

IEEE  802.11z - Extensions to Direct Link Setup (DLS) (Aug. 2007 - Dec. 2011)

There, that is probably much more than you ever wanted to know about the IEEE 802.11 standard.

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