2010-08-02 11:56:56

by Yogesh Ashok Powar

Subject: wireless-regdb: Why crda db.txt disallows 40Mhz BW on Channel 12-13 for JP?

Hello All,

Crda db.txt has following entries for JP:
(2402 - 2472 @ 40), (N/A, 20)
(2457 - 2482 @ 20), (N/A, 20)

Why are channel 12 and 13 for JP disallowed to operate in 40Mhz by this file?

As per Annex 11J of latest 802.11n spec, for Japan, channel 1-7 are allowed in HT40+ and channel 5-13 are allowed in HT40- mode.

Thanks,
Yogesh

2010-08-03 00:03:13

by Luis R. Rodriguez

Subject: Re: wireless-regdb: Why crda db.txt disallows 40Mhz BW on Channel 12-13 for JP?

On Mon, Aug 2, 2010 at 4:55 AM, yogeshp <[email protected]> wrote:
> Hello All,
>
> Crda db.txt has following entries for JP:
>        (2402 - 2472 @ 40), (N/A, 20)
>        (2457 - 2482 @ 20), (N/A, 20)
>
> Why are channel 12 and 13 for JP disallowed to operate in 40Mhz by this file?
>
> As per Annex 11J of latest 802.11n spec, for Japan, channel 1-7 are allowed in HT40+ and
> channel 5-13 are allowed in HT40- mode.

Do you mean Section 11J.1? That stuff defines a regulatory class, its
not a regulatory text though. Linux dynamically computes the HT40+ or
HT40- allowed channel map based on frequency ranges supported and the
max allowed bandwidth for its frequency ranges.

Michael, can you confirm if HT0 is allowed on the 2.4 GHz band in JP ?

Luis