[wireless-regdb] Question about 5.8 GHz in E.U.

Ryan Mounce ryan at mounce.com.au
Thu Sep 7 07:45:34 PDT 2017

On 7 September 2017 at 23:33, Mathieu Peyréga <mathieu.peyrega at gmail.com> wrote:
> Hello,
> unfortunately, my wifi skills are not (yet ?) allowing me to track further
> than what the "iw reg get" command tells me (confirmed by some off the shelf
> Wifi analyzer sofwares).
> Do you have pointers/tutorial to help me doing that ?

Try this

# find interface name
iw dev
# perform scan on interface
iw dev wlan0 scan -u

This previously dumped the country IE in a nice readable form, however
it no longer does on my device running LEDE master so you may not have
any luck depending on how new your distro is.

Typically for this task I would use monitor mode + Wireshark or my
favoured (sadly proprietary) WiFi surveying app, however I can only
provide advise for macOS.

> Further reading your answer, my guess is that DJI has complied to UNII-3
> choice. At least on their website Spark spec page, they clearly give the
> good max power figures and make the difference between FCC and EU areas.
> This leads to my concern about why not adding the matching rules in the DB
> for EU countries that have transposed it into their laws.
> Is this regulatory DB supposed to strictly reflect the current state of
> local regulations or doe it also endorse a higher level of "responsability"
> in order to prevent issues with non complient devices as I understand your
> fears ?

The regdb is only used in practice for 802.11 rather than as a
universal dictionary for radio regulations. My personal opinion is
that it should first reflect local regulations, and then subsequently
reflect established industry conventions that are more restrictive. In
this instance, the industry convention appears to be disabling the
UNII-3 range in Europe and I happen to agree more for practical
reasons than any sense of 'responsibility'.

> Regards
> Le 07/09/2017 à 15:44, Ryan Mounce a écrit :
>> You can see the 'FR' Country Code, can you see the full 802.11d
>> Country Information IE that is broadcast by the DJI drone?
>> I can see how this situation has come about. In much of the world
>> including China (DJI) and the USA (DJI's largest international market)
>> the 'UNII-3' equivalent range is a simple default choice with high
>> power and outdoor use permitted, with no DFS to worry about.
>> Europe is not so simple. In roughly descending order of device
>> compatibility.
>> 2.4GHz has power restrictions compared to USA/China, and is polluted
>> in every country.
>> UNII-1 is indoor only and should require the user to confirm they are
>> indoors (for a device like a drone that is likely to be used outdoors,
>> unlike a home WiFi AP)
>> UNII-2 adds DFS and TPC restrictions to UNII-1, quite restrictive.
>> UNII-2E is fairly quiet and allows more generous power, however DFS is
>> still a consideration and a portable device like a drone would have to
>> scan for at least 60 seconds before broadcasting in this band.
>> UNII-3 has the strictest power restrictions of all, and thus the most
>> limited range.
>> So it seems that DJI have simply ignored this altogether, and are
>> broadcasting in a poorly supported frequency band in Europe with
>> either a very weak short range signal or a very strong signal in
>> violation of regulations. Either way, this is very much their problem
>> (and unfortunately also their customers').
> --
> tel : +33 (0)6 87 30 83 59

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