wireless-regdb: update CA rules for 5600 - 5650 mHz

wireless-regdb: update CA rules for 5600 - 5650 mHz

[Wei Zhong]

commit 2fef4cad8a1bd9cbbf178e59a1b3ca672b057095
Author: Wei Zhong <wzhong@google.com>
Date:   Wed Jul 1 22:39:09 2015 -0700

    wireless-regdb: update CA rules for 5600 - 5650 mHz

    Related regulation:
    http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10971.html#s6.2.3

    Frequency Bands 5470-5600 MHz and 5650-5725 MHz
    Until further notice, devices subject to this section [i.e. Wifi device
    supporting 5 GHz bands] shall not be capable of transmitting in the band
    5600-5650 MHz. This restriction is for the protection of Environment
    Canada’s weather radars operating in this band.

diff --git a/db.txt b/db.txt
index 809cd3c..da0cfad 100644
--- a/db.txt
+++ b/db.txt
@@ -216,7 +216,8 @@ country CA: DFS-FCC
        (2402 - 2472 @ 40), (30)
        (5170 - 5250 @ 80), (17), AUTO-BW
        (5250 - 5330 @ 80), (24), DFS, AUTO-BW
-       (5490 - 5730 @ 160), (24), DFS
+       (5490 - 5600 @ 80), (24), DFS
+       (5650 - 5730 @ 40), (24), DFS
        (5735 - 5835 @ 80), (30)

 # Source:

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Seth Forshee]

On Wed, Jul 01, 2015 at 10:44:09PM -0700, Wei Zhong wrote:
> commit 2fef4cad8a1bd9cbbf178e59a1b3ca672b057095
> Author: Wei Zhong <wzhong@google.com>
> Date:   Wed Jul 1 22:39:09 2015 -0700
> 
>     wireless-regdb: update CA rules for 5600 - 5650 mHz
> 
>     Related regulation:
>     http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10971.html#s6.2.3
> 
>     Frequency Bands 5470-5600 MHz and 5650-5725 MHz
>     Until further notice, devices subject to this section [i.e. Wifi device
>     supporting 5 GHz bands] shall not be capable of transmitting in the band
>     5600-5650 MHz. This restriction is for the protection of Environment
>     Canada’s weather radars operating in this band.

Thanks for the patch. There are a couple of issues though, plus a
question.

First, this project requires that you add a Signed-off-by tag to the
commit message to acknowledge your agreement to the Developer
Certificate of Origin. Please see the CONTRIBUTING file for more
information.

Second, the patch is not in the correct format. It looks like to me you
pasted the output from git-show, which resulted in mangled white space
and other issues. Please use git-format-patch to create the patch, then
send it using git-send-email or else send the patch as an attachment.

> diff --git a/db.txt b/db.txt
> index 809cd3c..da0cfad 100644
> --- a/db.txt
> +++ b/db.txt
> @@ -216,7 +216,8 @@ country CA: DFS-FCC
>         (2402 - 2472 @ 40), (30)
>         (5170 - 5250 @ 80), (17), AUTO-BW
>         (5250 - 5330 @ 80), (24), DFS, AUTO-BW
> -       (5490 - 5730 @ 160), (24), DFS
> +       (5490 - 5600 @ 80), (24), DFS
> +       (5650 - 5730 @ 40), (24), DFS

Why isn't 80MHz channel bandwidth allowed in the 5650-5730 range?

Thanks,
Seth

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Wei Zhong]

Thanks for the reply. I'll fix the format and re-submit.

On Thu, Jul 2, 2015 at 6:48 AM, Seth Forshee <seth.forshee@canonical.com> wrote:
> On Wed, Jul 01, 2015 at 10:44:09PM -0700, Wei Zhong wrote:
>> commit 2fef4cad8a1bd9cbbf178e59a1b3ca672b057095
>> Author: Wei Zhong <wzhong@google.com>
>> Date:   Wed Jul 1 22:39:09 2015 -0700
>>
>>     wireless-regdb: update CA rules for 5600 - 5650 mHz
>>
>>     Related regulation:
>>     http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10971.html#s6.2.3
>>
>>     Frequency Bands 5470-5600 MHz and 5650-5725 MHz
>>     Until further notice, devices subject to this section [i.e. Wifi device
>>     supporting 5 GHz bands] shall not be capable of transmitting in the band
>>     5600-5650 MHz. This restriction is for the protection of Environment
>>     Canada’s weather radars operating in this band.
>
> Thanks for the patch. There are a couple of issues though, plus a
> question.
>
> First, this project requires that you add a Signed-off-by tag to the
> commit message to acknowledge your agreement to the Developer
> Certificate of Origin. Please see the CONTRIBUTING file for more
> information.
>
> Second, the patch is not in the correct format. It looks like to me you
> pasted the output from git-show, which resulted in mangled white space
> and other issues. Please use git-format-patch to create the patch, then
> send it using git-send-email or else send the patch as an attachment.
>
>> diff --git a/db.txt b/db.txt
>> index 809cd3c..da0cfad 100644
>> --- a/db.txt
>> +++ b/db.txt
>> @@ -216,7 +216,8 @@ country CA: DFS-FCC
>>         (2402 - 2472 @ 40), (30)
>>         (5170 - 5250 @ 80), (17), AUTO-BW
>>         (5250 - 5330 @ 80), (24), DFS, AUTO-BW
>> -       (5490 - 5730 @ 160), (24), DFS
>> +       (5490 - 5600 @ 80), (24), DFS
>> +       (5650 - 5730 @ 40), (24), DFS
>
> Why isn't 80MHz channel bandwidth allowed in the 5650-5730 range?

It could. But since the entire band is only 80 MHz, in practice, not a single
center_freq, channel 136 or140 for example, can utilities 80 MHz, right?

>
> Thanks,
> Seth

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Seth Forshee]

On Thu, Jul 02, 2015 at 07:21:30AM -0700, Wei Zhong wrote:
> Thanks for the reply. I'll fix the format and re-submit.

Thanks.

> > Why isn't 80MHz channel bandwidth allowed in the 5650-5730 range?
> 
> It could. But since the entire band is only 80 MHz, in practice, not a single
> center_freq, channel 136 or140 for example, can utilities 80 MHz, right?

I don't know, that's why I asked :-)

I actually haven't read up yet on how VHT80 is done in practice. I was
just curious why an 80 MHz channel wouldn't be possible when there's the
space for it.

Thanks,
Seth

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Zefir Kurtisi]

On 07/02/2015 07:44 AM, Wei Zhong wrote:
> commit 2fef4cad8a1bd9cbbf178e59a1b3ca672b057095
> Author: Wei Zhong <wzhong@google.com>
> Date:   Wed Jul 1 22:39:09 2015 -0700
> 
>     wireless-regdb: update CA rules for 5600 - 5650 mHz
> 
>     Related regulation:
>     http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10971.html#s6.2.3
> 
>     Frequency Bands 5470-5600 MHz and 5650-5725 MHz
>     Until further notice, devices subject to this section [i.e. Wifi device
>     supporting 5 GHz bands] shall not be capable of transmitting in the band
>     5600-5650 MHz. This restriction is for the protection of Environment
>     Canada’s weather radars operating in this band.
> 
> diff --git a/db.txt b/db.txt
> index 809cd3c..da0cfad 100644
> --- a/db.txt
> +++ b/db.txt
> @@ -216,7 +216,8 @@ country CA: DFS-FCC
>         (2402 - 2472 @ 40), (30)
>         (5170 - 5250 @ 80), (17), AUTO-BW
>         (5250 - 5330 @ 80), (24), DFS, AUTO-BW
> -       (5490 - 5730 @ 160), (24), DFS
> +       (5490 - 5600 @ 80), (24), DFS
> +       (5650 - 5730 @ 40), (24), DFS
>         (5735 - 5835 @ 80), (30)
> 
>  # Source:
> --

I believe this could also be interpreted differently. If the change is only about
removing the weather radar band (5600-5650), the change should be

 -       (5490 - 5730 @ 160), (24), DFS
 +       (5490 - 5570 @ 80), (24), DFS
 +       (5570 - 5590 @ 20), (24), DFS
 +       (5650 - 5730 @ 80), (24), DFS

The second rule explicitly states that channel 116 remains available for HT20. If
this level of strict correctness is not needed, rule 1 and 2 combined would be

 -       (5490 - 5730 @ 160), (24), DFS
 +       (5490 - 5590 @ 80), (24), DFS
 +       (5650 - 5730 @ 80), (24), DFS


Cheers
Zefir

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Wei Zhong]

On Fri, Jul 3, 2015 at 4:08 AM, Zefir Kurtisi <zefir.kurtisi@neratec.com> wrote:
>
> On 07/02/2015 07:44 AM, Wei Zhong wrote:
> > commit 2fef4cad8a1bd9cbbf178e59a1b3ca672b057095
> > Author: Wei Zhong <wzhong@google.com>
> > Date:   Wed Jul 1 22:39:09 2015 -0700
> >
> >     wireless-regdb: update CA rules for 5600 - 5650 mHz
> >
> >     Related regulation:
> >     http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10971.html#s6.2.3
> >
> >     Frequency Bands 5470-5600 MHz and 5650-5725 MHz
> >     Until further notice, devices subject to this section [i.e. Wifi device
> >     supporting 5 GHz bands] shall not be capable of transmitting in the band
> >     5600-5650 MHz. This restriction is for the protection of Environment
> >     Canada’s weather radars operating in this band.
> >
> > diff --git a/db.txt b/db.txt
> > index 809cd3c..da0cfad 100644
> > --- a/db.txt
> > +++ b/db.txt
> > @@ -216,7 +216,8 @@ country CA: DFS-FCC
> >         (2402 - 2472 @ 40), (30)
> >         (5170 - 5250 @ 80), (17), AUTO-BW
> >         (5250 - 5330 @ 80), (24), DFS, AUTO-BW
> > -       (5490 - 5730 @ 160), (24), DFS
> > +       (5490 - 5600 @ 80), (24), DFS
> > +       (5650 - 5730 @ 40), (24), DFS
> >         (5735 - 5835 @ 80), (30)
> >
> >  # Source:
> > --
>
> I believe this could also be interpreted differently. If the change is only about
> removing the weather radar band (5600-5650), the change should be
>
>  -       (5490 - 5730 @ 160), (24), DFS
>  +       (5490 - 5570 @ 80), (24), DFS
>  +       (5570 - 5590 @ 20), (24), DFS
>  +       (5650 - 5730 @ 80), (24), DFS
>
> The second rule explicitly states that channel 116 remains available for HT20. If
> this level of strict correctness is not needed, rule 1 and 2 combined would be
>
>  -       (5490 - 5730 @ 160), (24), DFS
>  +       (5490 - 5590 @ 80), (24), DFS

I agree. 5590 is more strict than 5600.

>
>  +       (5650 - 5730 @ 80), (24), DFS

5690 MHz is not a channel can be used, is it still necessary to mark
this band as 80MHz while in practice it is not possible to fully
unitize the entire band?

>
>
> Cheers
> Zefir

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Zefir Kurtisi]

On 07/03/2015 04:20 PM, Wei Zhong wrote:
> On Fri, Jul 3, 2015 at 4:08 AM, Zefir Kurtisi <zefir.kurtisi@neratec.com> wrote:
>>
>> On 07/02/2015 07:44 AM, Wei Zhong wrote:
>>> commit 2fef4cad8a1bd9cbbf178e59a1b3ca672b057095
>>> Author: Wei Zhong <wzhong@google.com>
>>> Date:   Wed Jul 1 22:39:09 2015 -0700
>>>
>>>     wireless-regdb: update CA rules for 5600 - 5650 mHz
>>>
>>>     Related regulation:
>>>     http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10971.html#s6.2.3
>>>
>>>     Frequency Bands 5470-5600 MHz and 5650-5725 MHz
>>>     Until further notice, devices subject to this section [i.e. Wifi device
>>>     supporting 5 GHz bands] shall not be capable of transmitting in the band
>>>     5600-5650 MHz. This restriction is for the protection of Environment
>>>     Canada’s weather radars operating in this band.
>>>
>>> diff --git a/db.txt b/db.txt
>>> index 809cd3c..da0cfad 100644
>>> --- a/db.txt
>>> +++ b/db.txt
>>> @@ -216,7 +216,8 @@ country CA: DFS-FCC
>>>         (2402 - 2472 @ 40), (30)
>>>         (5170 - 5250 @ 80), (17), AUTO-BW
>>>         (5250 - 5330 @ 80), (24), DFS, AUTO-BW
>>> -       (5490 - 5730 @ 160), (24), DFS
>>> +       (5490 - 5600 @ 80), (24), DFS
>>> +       (5650 - 5730 @ 40), (24), DFS
>>>         (5735 - 5835 @ 80), (30)
>>>
>>>  # Source:
>>> --
>>
>> I believe this could also be interpreted differently. If the change is only about
>> removing the weather radar band (5600-5650), the change should be
>>
>>  -       (5490 - 5730 @ 160), (24), DFS
>>  +       (5490 - 5570 @ 80), (24), DFS
>>  +       (5570 - 5590 @ 20), (24), DFS
>>  +       (5650 - 5730 @ 80), (24), DFS
>>
>> The second rule explicitly states that channel 116 remains available for HT20. If
>> this level of strict correctness is not needed, rule 1 and 2 combined would be
>>
>>  -       (5490 - 5730 @ 160), (24), DFS
>>  +       (5490 - 5590 @ 80), (24), DFS
> 
> I agree. 5590 is more strict than 5600.
> 
>>
>>  +       (5650 - 5730 @ 80), (24), DFS
> 
> 5690 MHz is not a channel can be used, is it still necessary to mark
> this band as 80MHz while in practice it is not possible to fully
> unitize the entire band?
> 

I must be missing something here, where does the restriction for 5690 come from?
The document handles the band 5650-5725 as available, I don't see any further
restrictions for 5690.


>From your other post:
>>     >
>>     >  -       (5490 - 5730 @ 160), (24), DFS
>>     >  +       (5490 - 5590 @ 80), (24), DFS
>> 
>>     I agree. 5590 is more strict than 5600.
>> 
>>  
>> On a second thought,  5590 implies channel 116 can't have 40MHz. I think that is
>> still allowed per regulation.
>> 
>> 

No, channel 116 is not usable for HT40 if weather radar channels are disabled,
since it can only be combined with channel 120 and that one partially falls into
the restricted range.

I found the FCC channel plans (which CA conforms to) in [1] very helpful when
checking the restrictions.


[1] https://apps.fcc.gov/kdb/GetAttachment.html?id=lp4w3WTVG9PReWNFG0ckTg%3D%3D

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Seth Forshee]

On Fri, Jul 03, 2015 at 05:01:20PM +0200, Zefir Kurtisi wrote:
> On 07/03/2015 04:20 PM, Wei Zhong wrote:
> > On Fri, Jul 3, 2015 at 4:08 AM, Zefir Kurtisi <zefir.kurtisi@neratec.com> wrote:
> >>
> >> On 07/02/2015 07:44 AM, Wei Zhong wrote:
> >>> commit 2fef4cad8a1bd9cbbf178e59a1b3ca672b057095
> >>> Author: Wei Zhong <wzhong@google.com>
> >>> Date:   Wed Jul 1 22:39:09 2015 -0700
> >>>
> >>>     wireless-regdb: update CA rules for 5600 - 5650 mHz
> >>>
> >>>     Related regulation:
> >>>     http://www.ic.gc.ca/eic/site/smt-gst.nsf/eng/sf10971.html#s6.2.3
> >>>
> >>>     Frequency Bands 5470-5600 MHz and 5650-5725 MHz
> >>>     Until further notice, devices subject to this section [i.e. Wifi device
> >>>     supporting 5 GHz bands] shall not be capable of transmitting in the band
> >>>     5600-5650 MHz. This restriction is for the protection of Environment
> >>>     Canada’s weather radars operating in this band.
> >>>
> >>> diff --git a/db.txt b/db.txt
> >>> index 809cd3c..da0cfad 100644
> >>> --- a/db.txt
> >>> +++ b/db.txt
> >>> @@ -216,7 +216,8 @@ country CA: DFS-FCC
> >>>         (2402 - 2472 @ 40), (30)
> >>>         (5170 - 5250 @ 80), (17), AUTO-BW
> >>>         (5250 - 5330 @ 80), (24), DFS, AUTO-BW
> >>> -       (5490 - 5730 @ 160), (24), DFS
> >>> +       (5490 - 5600 @ 80), (24), DFS
> >>> +       (5650 - 5730 @ 40), (24), DFS
> >>>         (5735 - 5835 @ 80), (30)
> >>>
> >>>  # Source:
> >>> --
> >>
> >> I believe this could also be interpreted differently. If the change is only about
> >> removing the weather radar band (5600-5650), the change should be
> >>
> >>  -       (5490 - 5730 @ 160), (24), DFS
> >>  +       (5490 - 5570 @ 80), (24), DFS
> >>  +       (5570 - 5590 @ 20), (24), DFS
> >>  +       (5650 - 5730 @ 80), (24), DFS
> >>
> >> The second rule explicitly states that channel 116 remains available for HT20. If
> >> this level of strict correctness is not needed, rule 1 and 2 combined would be
> >>
> >>  -       (5490 - 5730 @ 160), (24), DFS
> >>  +       (5490 - 5590 @ 80), (24), DFS
> > 
> > I agree. 5590 is more strict than 5600.
> > 
> >>
> >>  +       (5650 - 5730 @ 80), (24), DFS
> > 
> > 5690 MHz is not a channel can be used, is it still necessary to mark
> > this band as 80MHz while in practice it is not possible to fully
> > unitize the entire band?
> > 
> 
> I must be missing something here, where does the restriction for 5690 come from?
> The document handles the band 5650-5725 as available, I don't see any further
> restrictions for 5690.

I've only looked briefly at the relevant documents, but I also am not
seeing where this restriction comes from. The regulatory document linked
to in the patch description doesn't seem to restrict it, nor does
anything I see in the discussion of VHT80 center frequencies in IEEE
802.11 (in fact channel 138 is explicitly listed as a possible VHT80
center frequency index in some of the tables).

> From your other post:
> >>     >
> >>     >  -       (5490 - 5730 @ 160), (24), DFS
> >>     >  +       (5490 - 5590 @ 80), (24), DFS
> >> 
> >>     I agree. 5590 is more strict than 5600.
> >> 
> >>  
> >> On a second thought,  5590 implies channel 116 can't have 40MHz. I think that is
> >> still allowed per regulation.
> >> 
> >> 
> 
> No, channel 116 is not usable for HT40 if weather radar channels are disabled,
> since it can only be combined with channel 120 and that one partially falls into
> the restricted range.

It's not necessary to restrict the band down to 5590 or break out the
rule for channel 116 separately, the software is smart enough to work
out what's allowed based on the original rule Wei supplied for 5490-5600
MHz. In fact that rule exactly matches what we used to have in db.txt
for the US prior to the TDWR restrictions being lifted.

Seth

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Zefir Kurtisi]

On 07/06/2015 03:27 PM, Seth Forshee wrote:
> On Fri, Jul 03, 2015 at 05:01:20PM +0200, Zefir Kurtisi wrote:
>> On 07/03/2015 04:20 PM, Wei Zhong wrote:
>> [...]
>> From your other post:
>>>>     >
>>>>     >  -       (5490 - 5730 @ 160), (24), DFS
>>>>     >  +       (5490 - 5590 @ 80), (24), DFS
>>>>
>>>>     I agree. 5590 is more strict than 5600.
>>>>
>>>>  
>>>> On a second thought,  5590 implies channel 116 can't have 40MHz. I think that is
>>>> still allowed per regulation.
>>>>
>>>>
>>
>> No, channel 116 is not usable for HT40 if weather radar channels are disabled,
>> since it can only be combined with channel 120 and that one partially falls into
>> the restricted range.
> 
> It's not necessary to restrict the band down to 5590 or break out the
> rule for channel 116 separately, the software is smart enough to work
> out what's allowed based on the original rule Wei supplied for 5490-5600
> MHz. In fact that rule exactly matches what we used to have in db.txt
> for the US prior to the TDWR restrictions being lifted.
> 

Yes, the SW is smart and sane enough to extract the limitations even if they are
defined less restrictive than required. Which raises the general question of what
needs to be defined as rule and what can be relied on to be handled correctly by
the SW.

Example: why do we need to bother about the max-bw parameter for a rule at all? We
know there is no 160MHz channel within 5490 and 5600, as does the SW. If we wrote
(5490 - 5600 @ 160) instead of (5490 - 5600 @ 80), nothing would change.

To me it sounds not fully consistent to explicitly limit max-bw while relying on
SW to sanitize frequency ranges. Not that it really matters in practice, but it
has a potential to simplify the rules (i.e. provide max-bw parameter only if the
according country defines restrictions and leave SW to handle it otherwise).


Cheers,
Zefir

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Wei Zhong]

I have applied more restrictive rule for (5490-5590) and allowed 80Mhz
for (5650 - 5730).

The patch has been uploaded in another thread.
http://lists.infradead.org/pipermail/wireless-regdb/2015-July/000858.html

Thanks.

On Mon, Jul 6, 2015 at 7:40 AM, Zefir Kurtisi <zefir.kurtisi@neratec.com> wrote:
> On 07/06/2015 03:27 PM, Seth Forshee wrote:
>> On Fri, Jul 03, 2015 at 05:01:20PM +0200, Zefir Kurtisi wrote:
>>> On 07/03/2015 04:20 PM, Wei Zhong wrote:
>>> [...]
>>> From your other post:
>>>>>     >
>>>>>     >  -       (5490 - 5730 @ 160), (24), DFS
>>>>>     >  +       (5490 - 5590 @ 80), (24), DFS
>>>>>
>>>>>     I agree. 5590 is more strict than 5600.
>>>>>
>>>>>
>>>>> On a second thought,  5590 implies channel 116 can't have 40MHz. I think that is
>>>>> still allowed per regulation.
>>>>>
>>>>>
>>>
>>> No, channel 116 is not usable for HT40 if weather radar channels are disabled,
>>> since it can only be combined with channel 120 and that one partially falls into
>>> the restricted range.
>>
>> It's not necessary to restrict the band down to 5590 or break out the
>> rule for channel 116 separately, the software is smart enough to work
>> out what's allowed based on the original rule Wei supplied for 5490-5600
>> MHz. In fact that rule exactly matches what we used to have in db.txt
>> for the US prior to the TDWR restrictions being lifted.
>>
>
> Yes, the SW is smart and sane enough to extract the limitations even if they are
> defined less restrictive than required. Which raises the general question of what
> needs to be defined as rule and what can be relied on to be handled correctly by
> the SW.
>
> Example: why do we need to bother about the max-bw parameter for a rule at all? We
> know there is no 160MHz channel within 5490 and 5600, as does the SW. If we wrote
> (5490 - 5600 @ 160) instead of (5490 - 5600 @ 80), nothing would change.
>
> To me it sounds not fully consistent to explicitly limit max-bw while relying on
> SW to sanitize frequency ranges. Not that it really matters in practice, but it
> has a potential to simplify the rules (i.e. provide max-bw parameter only if the
> according country defines restrictions and leave SW to handle it otherwise).
>
>
> Cheers,
> Zefir

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Seth Forshee]

On Mon, Jul 06, 2015 at 04:40:56PM +0200, Zefir Kurtisi wrote:
> On 07/06/2015 03:27 PM, Seth Forshee wrote:
> > On Fri, Jul 03, 2015 at 05:01:20PM +0200, Zefir Kurtisi wrote:
> >> On 07/03/2015 04:20 PM, Wei Zhong wrote:
> >> [...]
> >> From your other post:
> >>>>     >
> >>>>     >  -       (5490 - 5730 @ 160), (24), DFS
> >>>>     >  +       (5490 - 5590 @ 80), (24), DFS
> >>>>
> >>>>     I agree. 5590 is more strict than 5600.
> >>>>
> >>>>  
> >>>> On a second thought,  5590 implies channel 116 can't have 40MHz. I think that is
> >>>> still allowed per regulation.
> >>>>
> >>>>
> >>
> >> No, channel 116 is not usable for HT40 if weather radar channels are disabled,
> >> since it can only be combined with channel 120 and that one partially falls into
> >> the restricted range.
> > 
> > It's not necessary to restrict the band down to 5590 or break out the
> > rule for channel 116 separately, the software is smart enough to work
> > out what's allowed based on the original rule Wei supplied for 5490-5600
> > MHz. In fact that rule exactly matches what we used to have in db.txt
> > for the US prior to the TDWR restrictions being lifted.
> > 
> 
> Yes, the SW is smart and sane enough to extract the limitations even if they are
> defined less restrictive than required. Which raises the general question of what
> needs to be defined as rule and what can be relied on to be handled correctly by
> the SW.
> 
> Example: why do we need to bother about the max-bw parameter for a rule at all? We
> know there is no 160MHz channel within 5490 and 5600, as does the SW. If we wrote
> (5490 - 5600 @ 160) instead of (5490 - 5600 @ 80), nothing would change.
> 
> To me it sounds not fully consistent to explicitly limit max-bw while relying on
> SW to sanitize frequency ranges. Not that it really matters in practice, but it
> has a potential to simplify the rules (i.e. provide max-bw parameter only if the
> according country defines restrictions and leave SW to handle it otherwise).

The database is just about capturing the rules of the various regulatory
bodies. I don't know off the top of my head if there are any cases today
where the maximum allowed badwidth in a given range is less than the
maximum possible bandwidth in that range, but it certainly doesn't seem
impossible. So I wouldn't call it inconsistent.

We aren't expecting the kernel to "sanitize" the frequency ranges
either. It doesn't rely on the regdb to tell it which frequencies are
legitimate.

Seth

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Zefir Kurtisi]

On 07/07/2015 10:11 PM, Seth Forshee wrote:
> On Mon, Jul 06, 2015 at 04:40:56PM +0200, Zefir Kurtisi wrote:
>> On 07/06/2015 03:27 PM, Seth Forshee wrote:
>>> On Fri, Jul 03, 2015 at 05:01:20PM +0200, Zefir Kurtisi wrote:
>>>> On 07/03/2015 04:20 PM, Wei Zhong wrote:
>>>> [...]
>>>> From your other post:
>>>>>>     >
>>>>>>     >  -       (5490 - 5730 @ 160), (24), DFS
>>>>>>     >  +       (5490 - 5590 @ 80), (24), DFS
>>>>>>
>>>>>>     I agree. 5590 is more strict than 5600.
>>>>>>
>>>>>>  
>>>>>> On a second thought,  5590 implies channel 116 can't have 40MHz. I think that is
>>>>>> still allowed per regulation.
>>>>>>
>>>>>>
>>>>
>>>> No, channel 116 is not usable for HT40 if weather radar channels are disabled,
>>>> since it can only be combined with channel 120 and that one partially falls into
>>>> the restricted range.
>>>
>>> It's not necessary to restrict the band down to 5590 or break out the
>>> rule for channel 116 separately, the software is smart enough to work
>>> out what's allowed based on the original rule Wei supplied for 5490-5600
>>> MHz. In fact that rule exactly matches what we used to have in db.txt
>>> for the US prior to the TDWR restrictions being lifted.
>>>
>>
>> Yes, the SW is smart and sane enough to extract the limitations even if they are
>> defined less restrictive than required. Which raises the general question of what
>> needs to be defined as rule and what can be relied on to be handled correctly by
>> the SW.
>>
>> Example: why do we need to bother about the max-bw parameter for a rule at all? We
>> know there is no 160MHz channel within 5490 and 5600, as does the SW. If we wrote
>> (5490 - 5600 @ 160) instead of (5490 - 5600 @ 80), nothing would change.
>>
>> To me it sounds not fully consistent to explicitly limit max-bw while relying on
>> SW to sanitize frequency ranges. Not that it really matters in practice, but it
>> has a potential to simplify the rules (i.e. provide max-bw parameter only if the
>> according country defines restrictions and leave SW to handle it otherwise).
> 
> The database is just about capturing the rules of the various regulatory
> bodies. I don't know off the top of my head if there are any cases today
> where the maximum allowed badwidth in a given range is less than the
> maximum possible bandwidth in that range, but it certainly doesn't seem
> impossible. So I wouldn't call it inconsistent.
> 
> We aren't expecting the kernel to "sanitize" the frequency ranges
> either. It doesn't rely on the regdb to tell it which frequencies are
> legitimate.
> 
> Seth
> 
Sure and understood. Still I see room for ambiguity.

My claim is that in its current state the regdb does not exactly formalize the
limitations given by regulatory for a simple reason: it uses channel semantics
where it should only handle frequency ranges. Take the discussed rules for CA at
hand: while the linked document considers frequencies from 5150 to 5350, the
according rule for CA is defined as (5170 - 5250 @ 80). Why 5170 instead of 5150?
Because we know there is no channel defined below 5170 - but why do we need to
embed this information as a rule when it is already handled by SW?

In the current regdb, both semantics are used, e.g. UA (5150-5350) vs. CA
(5170-5250) or ES (5470-5725) vs. FI (5490-5710)).

This might sound like an irrelevant difference, but here is why it matters: the
above mentioned rules for ES and FI would give the same channel lists - as long as
we think in HT20 and HT40. But only ES gives access to 10 and 5MHz operation on
channel 144.


My bottom line is: regulatory rules must not contain channel semantics - this is
done by the SW. Rules must be a literal formalization of the country's regulatory,
which always uses frequency ranges within defined band edges.


Sorry for this going off-topic. It has nothing to do with the changes proposed by
Wei, but is more about something to keep in mind when considering upcoming support
for narrow band channels at band edges.



Thanks,
Zefir

Re: wireless-regdb: update CA rules for 5600 - 5650 mHz

[Seth Forshee]

On Wed, Jul 08, 2015 at 12:19:18PM +0200, Zefir Kurtisi wrote:
> My claim is that in its current state the regdb does not exactly formalize the
> limitations given by regulatory for a simple reason: it uses channel semantics
> where it should only handle frequency ranges. Take the discussed rules for CA at
> hand: while the linked document considers frequencies from 5150 to 5350, the
> according rule for CA is defined as (5170 - 5250 @ 80). Why 5170 instead of 5150?
> Because we know there is no channel defined below 5170 - but why do we need to
> embed this information as a rule when it is already handled by SW?
> 
> In the current regdb, both semantics are used, e.g. UA (5150-5350) vs. CA
> (5170-5250) or ES (5470-5725) vs. FI (5490-5710)).

I'm not surprised. I don't know that anyone has given it that much
thought before.

> This might sound like an irrelevant difference, but here is why it matters: the
> above mentioned rules for ES and FI would give the same channel lists - as long as
> we think in HT20 and HT40. But only ES gives access to 10 and 5MHz operation on
> channel 144.

Good example.

> My bottom line is: regulatory rules must not contain channel semantics - this is
> done by the SW. Rules must be a literal formalization of the country's regulatory,
> which always uses frequency ranges within defined band edges.

I'm generally in agreement. I'll try to pay closer attention to this in
the future.

> Sorry for this going off-topic. It has nothing to do with the changes proposed by
> Wei, but is more about something to keep in mind when considering upcoming support
> for narrow band channels at band edges.

Except that it seems to have inspired Wei to change the patch to do
exactly what you're arguing against ;-)

Seth