Forum

What are the best sources of information available at this point for learning about the future standard?
I see the draft is not accessible to ordinary people.

thank you

http://www.cwnp.com/community/blogsection

We have lots of articles on 802.11n and many more to come.

Various vendors have released whitepapers on 802.11n (Aruba, Cisco, Meru, etc), though not all of them are completely accurate and you have to resign yourself to dealing with the marketing thrown at you in these whitepapers.

Devinator

Yes, thank you, I do try and read everything that's posted on this site.
Is there a list of what features are mandatory and which are optional in draft n ?
Have more features become mandatory in draft 2?
Does draft n say anything about QoS support?

thanks again

Is there a list of what features are mandatory and which are optional in draft n?

Devinator >> unfortunately not, though the Wi-Fi Alliance has a list of what it will be testing in the first "certification". That document nor its contents is publicly available.

Have more features become mandatory in draft 2?

There's no "differential" document between draft 1 and draft 2.

Does draft n say anything about QoS support?

QoS is found in 802.11e (or 802.11-2007).

Thanks,

Devinator

Which of the 802.11n features are the ones that allow for greater coverage to 802.11g stations?

If I have an 802.11n network but only g clients, is there a speed improvement or not?

thanks in advance for your comments

http://www.atheros.com/pt/whitepapers/MIMO_Pwr3_whitepaper.pdf

http://www.cisco.com/en/US/netsol/ns767/networking_solutions_white_paper0900aecd806b8ce7.shtml

Aruba and Meru also have really nice whitepapers that will help answer your questions as well.

Devinator

Devinator,
I have read the documents you mentioned (again) and some things on the Meru and Aruba sites. I don't see much data to respond to my questions except an Aruba WP which says:
"As long as even a few legacy clients exist, the expected capacity improvements are unlikely to be realized. Legacy devices are also unable to take advantage of improvements in range and uniformity of coverage: if 802.11n APs are spaced farther apart to lower costs, legacy clients will likely run into more coverage problems than before." (quote from Designed for Speed, Peter Thornycroft May 2007 V2.7)

I was under the impression that there were some improvements even for just g clients. Was I wrong? Do you always need an n client?

thanks again

In the Atheros paper, it talks about Space Time Block Coding (STBC) which relates directly to your questions.

It's almost a sure bet that you'll see little to no enhancements for 802.11a/b/g clients when using an 802.11n infrastructure. What's worse is that with the 802.11a/b/g clients present, the 802.11n stations will see minimum speed improvements.

It's MUCH better to upgrade your clients to 802.11n first and then your infrastructure to 802.11n.

http://sdm3.rm04.net/ctt?kn=24&m=1160561&r=ODU0NjEyNzQS1&b=2&j=MzQ5NDI3NzES1&mt=1

Here's another article that I think you should read as well. I couldn't agree more with Dave's stance on deploying 802.11n.

Devinator

thanks for your help and all the links.

How about this quote?

"The latest ?¡é?€??n?¡é?€?? equipment is interoperable, too; a Belkin laptop card works with Apple?¡é?€??s router, and so on, although not at full speed. Better yet, the old ?¡é?€??b?¡é?€?? and ?¡é?€??g?¡é?€?? laptops can still enjoy the improved range of the ?¡é?€??n?¡é?€?? routers, although at ?¡é?€??b?¡é?€?? and ?¡é?€??g?¡é?€?? speeds."

From:
http://www.nytimes.com/2007/04/12/technology/12pogue.html?pagewanted=1&_r=2&ref=technology