3 ms·

I worked in this field for a while, and had my own novel mechanism for solving a problem. The major issue I had and I suspect this will have, is with devices t

I worked in this field for a while, and had my own novel mechanism for solving a problem. The major issue I had and I suspect this will have, is with devices that don't play by the rules. The unit economics mean the manufacturer is going to squeeze everything out, and if they can 'cheat' and claim higher numbers they will. Back ten years ago the issue was devices ignoring CTS frames but this feels similar.

avidiax 2y ago
When I worked on WiFi at Microsoft, we discovered that Apple was cheating. Apple was implemented a random backoff timer to have less range than the spec, which would mean that Apple devices win most contentions. We decided not to copy this into Windows, since it would be a race to the bottom.
- ajb 2y ago
  Wow. Do you (or anyone) know if they still do it? Was there any pushback on them?
  - avidiax 2y ago
    I don't know. It's possible that it was merely a bug, and maybe it was fixed at some point. But it's also not something that would cause noticeable issues on a network. Apple devices performing slightly better wouldn't be a big red flag. There are many reasons that this could be the case, from a better implementation, better testing, better HW (antennas), a different OS with a better TCP stack, etc.
- Salgat 2y ago
  What's the legality of devices intentionally violating wifi standards and causing potential issues with other devices? Is this something the FCC could act on?
  - linuxlizard 2y ago
    There's no laws about it. It's mostly a "handshake agreement" enforced via the WiFi Alliance. You go through the WFA certification process to get the "WiFi Certified" sticker. https://www.wi-fi.org/certification https://www.wi-fi.org/certification Usually large vendors try to do the right thing.
  - sokoloff 2y ago
    Aren't the 2.4 and 5 GHz bands among the unlicensed ISM bands? So long as you're complying with the general rules for the ISM bands, I'd expect the FCC doesn't care about you following the details of a specific protocol.
    - lazide 2y ago
      FCC rules are they you aren’t allowed to ‘intentionally interfere’ with other users of bands. As to what that exactly means, and where the line is drawn is up for debate. I doubt Apple would necessarily lose here, but ‘wifi jammers’ on Amazon would, for example.
      - sandworm101 2y ago
        This might be apple silently poking at the FCC et al, daring them to actualy speak up and thereby better define the rules. It's like how the marvel movies have been using the word "shit" once per movie in an attempt to force the MPAA to better articulate its rules. They dare the MPAA to slap an R rating on the next IronMan as Apple dares the WiFi alliance to disallow the wifi logo on the next iphone.
        avidiax 2y ago
        This is not in scope for the FCC. Anyone can use the ISM bands however they'd like, with certain power and bandwidth restrictions. It's in-scope for the WiFi alliance, but I don't see this as "poking" them. It's either a bug, or it's a way to get your devices to work a bit better than the competition, but in a way that the WiFi alliance would never notice.
- seagullz 2y ago
  If it got tested and verified, wasn't their WiFi Alliance certification supposed to be revoked?
  - avidiax 2y ago
    I would guess that this aspect of the spec was not well tested. It is possible to write a test that causes 100 or 1000 collisions and plots the random distribution of the backoffs, but that is pretty complicated versus just checking that 1 collision had a backoff that was within range.
- orev 2y ago
  Was it a small difference from the spec, like an off by one error might be, or was it an order of magnitude difference that might point to it being significant and intentional? (Of course dropped 0 could also be a bug). That’s a fairly important detail for a claim like this.
- hoseja 2y ago
  Why would you not race? Why be nice to Apple? Accelerate.
  - sandworm101 2y ago
    Because there is no race. Anyone can just set the backoff to zero and "win" by burning down the stadium so nobody else can play.

avidiax 2y ago

When I worked on WiFi at Microsoft, we discovered that Apple was cheating. Apple was implemented a random backoff timer to have less range than the spec, which would mean that Apple devices win most contentions. We decided not to copy this into Windows, since it would be a race to the bottom.

ajb 2y ago
Wow. Do you (or anyone) know if they still do it? Was there any pushback on them?
- avidiax 2y ago
  I don't know. It's possible that it was merely a bug, and maybe it was fixed at some point. But it's also not something that would cause noticeable issues on a network. Apple devices performing slightly better wouldn't be a big red flag. There are many reasons that this could be the case, from a better implementation, better testing, better HW (antennas), a different OS with a better TCP stack, etc.
Salgat 2y ago
What's the legality of devices intentionally violating wifi standards and causing potential issues with other devices? Is this something the FCC could act on?
- linuxlizard 2y ago
  There's no laws about it. It's mostly a "handshake agreement" enforced via the WiFi Alliance. You go through the WFA certification process to get the "WiFi Certified" sticker. https://www.wi-fi.org/certification https://www.wi-fi.org/certification Usually large vendors try to do the right thing.
- sokoloff 2y ago
  Aren't the 2.4 and 5 GHz bands among the unlicensed ISM bands? So long as you're complying with the general rules for the ISM bands, I'd expect the FCC doesn't care about you following the details of a specific protocol.
  - lazide 2y ago
    FCC rules are they you aren’t allowed to ‘intentionally interfere’ with other users of bands. As to what that exactly means, and where the line is drawn is up for debate. I doubt Apple would necessarily lose here, but ‘wifi jammers’ on Amazon would, for example.
    - sandworm101 2y ago
      This might be apple silently poking at the FCC et al, daring them to actualy speak up and thereby better define the rules. It's like how the marvel movies have been using the word "shit" once per movie in an attempt to force the MPAA to better articulate its rules. They dare the MPAA to slap an R rating on the next IronMan as Apple dares the WiFi alliance to disallow the wifi logo on the next iphone.
      - avidiax 2y ago
        This is not in scope for the FCC. Anyone can use the ISM bands however they'd like, with certain power and bandwidth restrictions. It's in-scope for the WiFi alliance, but I don't see this as "poking" them. It's either a bug, or it's a way to get your devices to work a bit better than the competition, but in a way that the WiFi alliance would never notice.
seagullz 2y ago
If it got tested and verified, wasn't their WiFi Alliance certification supposed to be revoked?
- avidiax 2y ago
  I would guess that this aspect of the spec was not well tested. It is possible to write a test that causes 100 or 1000 collisions and plots the random distribution of the backoffs, but that is pretty complicated versus just checking that 1 collision had a backoff that was within range.
orev 2y ago
Was it a small difference from the spec, like an off by one error might be, or was it an order of magnitude difference that might point to it being significant and intentional? (Of course dropped 0 could also be a bug). That’s a fairly important detail for a claim like this.
hoseja 2y ago
Why would you not race? Why be nice to Apple? Accelerate.
- sandworm101 2y ago
  Because there is no race. Anyone can just set the backoff to zero and "win" by burning down the stadium so nobody else can play.