- WIMAX-The worldwide Interoperability for microwave access.
- It is based on the IEEE 802.16 standard , which is also called wireless MAN.
- The name WIMAX was created by the WIMAX-forum, which was formed in June 2001 to promote conformance and interoperability of the standard.
- 802.16 it is not the actual standard .The is correctly called 802.16.2004
- 802.16e It is amendment to 802.16-2004.It is properly referred to as 802-16e-2005
- FIXED WIMAX Systems built using 802.16-2004 as air interface technology.
- Mobile WIMAX System built using 802-16-2005 as air technology.
- Connecting wi-fi hot spots with each other and to other parts of the internet.
- Providing a wireless alternative to cable and DSL for last mile (last km) broadband access.
- Providing high speed data and telecommunication series.
- Providing normadic connectivity.
- Many companies are closely examining WIMAX for “last mile” connectivity at high data rates.
- It could result in lower pricing for both home and business customers as competition lower prices.
- Cellular companies are evaluating WIMAX as a means of increasing band width for a variety of data intensive applications.
- WIMAX can enhance wireless infrastructure in an inexpensive way.
- WIMAX is very different from WI-FI in the way it works.
- MAC (media access controller)-It provides addressing and channel access control mechanisms.
- 80.2.16-2004 was updated to 802-16-2005 and uses scalable orthogonal frequency division multiple access (SOFDMA) as opposed to the OFDM version (256 sub carriers).
- It also uses multiple antenna support through MIMO (multiple input multiple output communications).
SPECTRUM ALLOCATION ISSUES
- The 802.16 specification applies across a wide swath of the RF spectrum.
- There is no uniform global licensed spectrum for WIMAX.
- US will 2.5 GHz and Asian countries like India ,Vietnam and Indonesia will use 3.3
- Manufactures are compelled to provide multi-spectrum devices.
- WIMAX has advantage of spectral efficiency. (WIMAX—spectral efficiency is 3.7 bits/s/Hz). (WI-FI—spectral efficiency is less than 1 bit/s/Hz).
- Requirement of low cost chipsets .
- Intel is a leader in promoting WIMAX and developed its own chipsets.
- Some of the other semiconductor companies which work on WIMAX are-[Alter, Beceen, GCI, Runcom, picochip (chipsets for base station)].
- WIMAX is a long range system that uses licensed or unlicensed spectrum.
- Wi-fi is a short range system that uses unlicensed spectrum .
- A commonly held misconception is that WIMAX will deliver 70 bits/sec over 30 miles.
- WIMAX devices typically have an antenna which is of lower gain by nature due to their inherent omni directional design.
- WIMAX main competition comes from existing deployed wireless system such as