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 > 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 >> davecb@spamcop.net | -- Mark Twain >> >> >> _______________________________________________ >> Bloat mailing list >> Bloat@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/bloat > > > -- > David Collier-Brown, | Always do right. This will gratify > System Programmer and Author | some people and astonish the rest > davecb@spamcop.net | -- Mark Twain > > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > -- David Collier-Brown, | Always do right. This will gratify System Programmer and Author | some people and astonish the rest davecb@spamcop.net | -- Mark Twain