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I am having trouble finding an answer on this... Most clients are coming with a cheap 1x1 N wifi card. What is the fastest speed they will support? My Cisco Press "Designing and Deploying 802.11n" book says 802.11n Modulation Techniques for One Spatial Stream (40-MHz Channel)is 135Mb/s max

If I read that right a 1x1 N client running at 40MHz can run up to 135Mb/s? I guess I figured a 1x1 wouldn't support 40MHz. Am I missing something?

thanks

Max depends on the capabilities of the client and the AP. Does it support 40 MHZ? Does it support short guard interval?

1 Spatial stream. MAX
65 Mbit/s

1 Spatial stream. 40 MHz Channel compatible. MAX
135 Mbit/s

1 Spatial stream. Shout Guard interval compatible. MAX
72.2 Mbit/s

1 Spatial stream. 40 MHz and short guard interval compatible. MAX
150 Mbit/s

Does 802.11n require support of 40MHz channels?

thanks

Somebody correct me if I am wrong but I do not believe it requires support of 40MHz channels. I Believe it offers support of 40 MHz channels.

Personally I think the benefit of a 1x1 "n" solution is going to be it's compatibility with the rest of the "n" network. WMM-PS may gain you some battery life too.

The speed increase with only a single stream 20 MHz channel is not that much. If you live in an urban environment and put 40MHz in the 2.4GHZ range you're going to have a lot of upset neighbors. Live way out there by yourself, then go for it.

I think the FCC is really blowing it by not disallowing 40MHz in the 2.4 GHz range.

Sean is right that 40 MHz is not required in 802.11n. The Wi-Fi Alliance does test 40 MHz support in 5 GHz as an optional 802.11n feature, but they do not test it in 2.4 GHz because it is generally not recommended.

FranMan, for future reference, you can also download the 802.11n-2009 spec from the IEEE. Find clause 20.6 for the MCS tables, which tells you the maximum data rate for each combination of 802.11n parameters.

http://standards.ieee.org/about/get/802/802.11.html