Radar returns are very weak, and a nearby device operating on a channel
that is reserved (in Canada and the US) for the radar can in principle
look like the echo from quite a large storm.
--dave
On 08/10/15 05:36 PM, Rosen Penev wrote:
How does a router that transmits at milliwatts interfere with airport
equipment? This seems like such an isolated case. At the very least
would it not require the routers to be relatively close?
On Thu, Oct 8, 2015, 13:20 David Collier-Brown <[email protected]
<mailto:[email protected]>> wrote:
Anyone who's an American citizen want to write a short
to-the-point response suggesting that this was vendor error,
caused by not using the database that linux uses for wi-fi cards?
I want them to have a public "out" from the current scheme of
telling the vendors to protect their code.
I prefer to give the FCC the option of telling the vendors to stop
messing up their code, like a regulatory agency would like to be
seen doing (;-))
About one page!
--dave
On 08/10/15 04:11 PM, David Collier-Brown wrote:
From tlkingan at
http://tech.slashdot.org/comments.pl?sid=8141531&cid=50686561
And that's what the FCC really wants The problem the FCC is
seeing right now is the modified firmware allows access to
frequencies that aren't allowed to be used for WiFI in the US.
This is more than just channels 12 and 13 on 2.4GHz, but also on
the complex 5GHz band.
The FCC has many complaints already from airports and other
entities whose radar is being interfered with by 5GHz WiFi (the
band plan is complex enough that channels are "locked out"
because they're used by higher priority services like radar).
And you really can't blame the open firmware guys either - mostly
because they don't know any better and they only build one binary
that works for all devices worldwide. (the available channels on
5GHz vary per country - depending on the radar in use).
All the FCC really wants (and they've clarified it in the Notice
of Proposed Rulemaking) is the steps wifi manufacturers are
taking to prevent people from loading on firmware that does not
comply with FCC regulations - i.e., allows transmissions on
frequencies they are not allowed to transmit on.
It can either take place as hardware (filters blocking out the
frequencies), or software that cannot be modified by the open
firmware (e.g., firmware on wifi chip reads a EEPROM or something
and locks out those frequencies).
The thing it cannot be is rely on "goodwill" or firmware that
respects the band plan - i.e., you cannot rely on "blessed" open
firmware that only uses the right frequencies (because anyone can
modify it to interfere).
The FCC has all the powers to enforce compliance right now -
users of open firmware who are caught creating interference with
higher priority services can already be fined, equipment seized
and all that stuff (and that would not include just the WiFi
router - any WiFi device like PCs can be seized if they attach to
that network). That's the heavy handed legal approach they have.
However, they don't want to do that, because most users probably
don't realize the problem, and the FCC really doesn't want to
destroy all that stuff. So instead, the FCC is working with
manufacturers to fix the issue at the source.
The problem lies in the fact that most manufacturers are cheap
and will not spend a penny more, so instead of locking out the
radio from interfering, they'll lock out the entire firmware.
The FCC mentions DD-WRT and all that by name because their
investigations revealed that when they investigate interference,
the offending routers run that firmware (and which doesn't lock
out frequencies that they aren't supposed to transmit on).
--
David Collier-Brown, | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
[email protected] <mailto:[email protected]> |
-- Mark Twain
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David Collier-Brown, | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
[email protected] <mailto:[email protected]> |
-- Mark Twain
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--
David Collier-Brown, | Always do right. This will gratify
System Programmer and Author | some people and astonish the rest
[email protected] | -- Mark Twain
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