Talk:IEEE 802.11a-1999

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Number of Channels[edit]

More discussion of the channels would be useful. The article states 12/13 non-overlapping channels, but also states that the spread is 20 MHz. As the band is 5725 to 5850 MHz, this suggests only 5 non-overlapping bands. (Books I have read suggest 8.) I cannot get my head around all this so, presumably, others will also be having trouble. HairyWombat (talk) 21:19, 28 June 2008 (UTC)

They really are non-overlapping since they start (in the U.S.) at 5180Mhz. But more appropriate for List of WLAN channels. -- KelleyCook (talk) 15:14, 29 June 2008 (UTC)

Hadn't seen List of WLAN channels, which is really useful. Confusingly, the FCC regulations seem to only speak of 5725 to 5850 MHz. (This means my figure of "5" for the band I quoted is correct. This is encouraging.) HairyWombat (talk) 16:10, 29 June 2008 (UTC)

FCC Part 15[edit]

Is it worth discussing the FCC rules in the article? They state that for point-to-point links, the transmitter power can remain at 1 Watt even when using a high-gain antenna. (This is not the case down in the 2.4 GHz band used by 802.11b/g.) HairyWombat (talk) 21:19, 28 June 2008 (UTC)

That would be more than welcome, IMO. Make sure that you reference WP:Reliable sources. -- KelleyCook (talk) 15:14, 29 June 2008 (UTC)

The source would have to be the FCC regulations, but these seem to only mention 5725 to 5850 MHz. Talk:List_of_WLAN_channels gives more detail. I don't understand all of this, so cannot contribute to the article. HairyWombat (talk) 16:10, 29 June 2008 (UTC)

More references needed?[edit]

It'd probably be good to have more references for some of the information in this article, such as claims that the hardware for 5GHz radio devices is/was too expensive. Rohaq (talk) 21:23, 11 April 2011 (UTC)

Computing time from packet size[edit]

I noticed the [clarification needed] on the last column of the table, so here's a formula for calculating the time in microseconds to transmit n bytes of data at a rate of R megabits per second.

T = 20 + 4 * ceil((16+(n+28)*8+6) / (4 * R))

This includes preambles, signal fields, MAC headers and CRC. I'll leave it to someone else to update the table – it appears to be slightly incorrect in these numbers. — Preceding unsigned comment added by 18.111.100.152 (talk) 19:43, 22 February 2012 (UTC)

...on second thought, that may not be quite right due to puncturing. I would have to think about it more. But I think that will be right to within about 4 microseconds. — Preceding unsigned comment added by 128.31.35.248 (talk) 02:01, 23 February 2012 (UTC)