Work on 802.16 started early 2000, and was completed in Dec
2001. The interesting fact about the original 802.16 is that it was never meant
to become a mass market technology. 802.16 was originally developed for
corporate access and backhaul. It only specified bands in the >10GHz range and
LOS channels only.
Work on 802.16a started on late 2001, and was completed early
2003. 802.16a added NLOS channels. 802.16a also specified bands in the 2-11 GHz
range.
The latest version of the standard is 802.16-2004 which
basically combines both previous standards into one. WiMax is based on
802.16-2004.
802.16e is currently under works, it may actually be released by
the time you read this article. It was supposed to be complete early October of
2005. 802.16e will add mobile deployment to WiMax, which is very interesting
since 802.20 is trying to accomplish just that. The main difference between is
that 802.16e will operate in the 2-6 GHz band, while 802.20 will operate in the
licensed >3.5 GHz. 802.16e has a huge advantage over 802.20 now because of
the fact that 802.16e is not starting from scratch. It is based on an existing
standard, and 802.16e equipment is expected to hit the market much earlier than
802.20.
The following table provides a quick summary of the changes 802.16 went
through.
From: Intel WiMax Presentation
