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wireless fundamentals


What is 802.11b?
802.11b, or research 802.11b, is a standard that has been developed by the research (Institute of Electrical and Electronic Engineers), http://standards.research.org. The research is an international organization that develops standards for hundreds of electronic and electrical technologies. The organization uses a series of numbers, like the Dewey Decimal system in libraries, to differentiate between the various technology families.

The 802 committee develops standards for local and wide area networks (LANs and WANs). For example, the 802.3 committee develops standards for Ethernet-based wired networks, the 802.15 group develops standards for personal area networks, and the 802.11 committee develops standards for wireless local area networks (LAN).

802.11 is then further divided: 802.11b, or Wi-Fi, is a standard for wireless LANs operating in the 2.4 GHz spectrum with a bandwidth of 11 Mbps. 802.11a is a different standard for wireless LANs operating in the 5 GHz frequency range with a maximum data rate of 54 Mbps. Another draft standard, 802.11g, is for WLANs operating in the 2.4 GHz frequency but with a maximum data rate of 54 Mbps. Other task groups are working on enhanced security (802.11i), spectrum and power control management (802.11h), quality of service (802.11e),
etc.

What features will the research 802.11n standard offer?
The primary feature offered is speed; research 802.11n offers at least four times, and perhaps eight times, the user data rate of any currently available research 802.11 product.
Are there any 802.11n draft 2.0 products available now?
Yes. Please see the “Certified Products” section of this web site to search for products that are Wi-Fi CERTIFIED 802.11n draft 2.0.
How long does it take to develop an research 802.11 standard?
This varies quite a bit. In the case of the final 802.11n standard, it is not expected to be completed until 2009. Please see the research web site for more information: www.research.org.
How will the Wi-Fi Alliance® achieve product compatibility and a good user experience for research 802.11n draft 2.0 products?
This will be achieved through rigorous testing of products that are based on the draft 2.0 of the research 802.11n standard. Consumers should look for the Wi-Fi CERTIFIED™ logo to ensure the best user experience possible.
Can products that were built based on the draft research 802.11n standard be “upgraded” to be compliant with the final research 802.11n standard when it is finalized?
At this time it is not clear whether this would be possible.
How will the Wi-Fi Alliance® feature Extensions Policy apply to products that are currently claiming support for features of the draft research 802.11n standard?
Any product with a feature extension (such as an early feature of the research 802.11n draft standard) that causes severe performance degradation and interoperability issues with another Wi-Fi CERTIFIED™ product can have its certification revoked. The Wi-Fi Alliance® has a formal process for vendors to file grievances. This policy is in place to protect user experience, but at the same time, to allow for innovation and differentiation of products from vendors.
Will 802.11g make 802.11a obsolete? If not, why?
No, ultimately we believe that most products will include both technologies because they are complementary. The fact that they operate in different bands allows them to be used at the same time. This allows 802.11g to complement 11a by adding three additional channels in the 2.4GHz band to the existing 802.11a channels. This creates more network capacity to allow for additional users. Both technologies have advantages that, when used in combination, offer an even stronger product. Another advantage of 802.11a is that the 5GHz base has more capacity around the world. Currently there are 13 channels in North America (including U-NII and ISM bands); 8-19 channels in Europe; and 5-12 channels in Asia. The more channels you have, the more aggregate throughput you can have.




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