[wireless-regdb] [RFC] wireless-regdb: Update 5 GHz rules for Canada
Matthias May
matthias.may at neratec.com
Mon Feb 13 05:58:28 PST 2017
On 07/02/17 15:04, Seth Forshee wrote:
> On Tue, Feb 07, 2017 at 08:52:30AM +0100, Johannes Berg wrote:
>> On Mon, 2017-02-06 at 14:50 -0600, Seth Forshee wrote:
>>> + (5150 - 5250 @ 80), (23), AUTO-BW
>>
>> For 20 MHz this is right, since the document says:
>>
>> The maximum e.i.r.p. shall not exceed 200 mW or 10 + 10 log10 B,
>> dBm, whichever power is less. B is the 99% emission bandwidth in
>> megahertz. The e.i.r.p. spectral density shall not exceed 10 dBm in
>> any 1.0 MHz band.
>>
>> However, for < 20 MHz, like 5 or 10, which we in theory do support, you
>> can't use that much due to the spectral density requirement. It seems
>> possible that that's where the 17 dBm came from, since 10 + 10 log10(5)
>> is about 17.
>
> Yes, thanks. I had forgotten to consider bandwidths less than 20 MHz.
>
> Seth
>
> _______________________________________________
> wireless-regdb mailing list
> wireless-regdb at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/wireless-regdb
>
According to .../include/net/cfg80211.h
>static inline int
>ieee80211_chandef_max_power(struct cfg80211_chan_def *chandef)
>{
> switch (chandef->width) {
> case NL80211_CHAN_WIDTH_5:
> return min(chandef->chan->max_reg_power - 6,
> chandef->chan->max_power);
> case NL80211_CHAN_WIDTH_10:
> return min(chandef->chan->max_reg_power - 3,
> chandef->chan->max_power);
> default:
> break;
> }
> return chandef->chan->max_power;
>}
This looks to me like it already handles the reduction of power
according to bandwidth.
BR
Matthias
More information about the wireless-regdb
mailing list