Apple WWDC keynote Wi-Fi fail: Glenn Fleishman explains what happened


Wireless technology writer Glenn Fleishman has a good, technically precise, but very readable (for non-engineers) explanation of exactly what went wrong with the wireless internet connectivity in the room during Steve Jobs' keynote yesterday at Apple's World Wide Developer Conference.

Our Dean Putney and Rob Beschizza were live-photoblogging the event, and as they reported, that connectivity problem caused conspicuous glitches during Mr. Jobs' on-stage presentation.

Apple apparently did offer a public Wi-Fi network at the WWDC launch, according to media and attendees I've polled. And those who tried it said that network did work initially. But with so much media in the audience, and the history of conference/event Wi-Fi networks having glitches at peak times--with many people liveblogging and uploading photos from the event--those who had MiFis chose to use those instead.

Wi-Fi can cope with a lot of so-called interference, but the protocol wasn't designed to handle hundreds of overlapping networks in a small space. (Interference is really the limits of a radio to distinguish signals out of noise, not a physical property of radio waves.)

Five Hundred Wi-Fi Networks Walk into a Bar (Future Tense)

Photo: Dean Putney


      1. I was going to go with “riff-raff giving fashion advice to billionaires is so yesterday,” but yours is pretty good, too.

  1. According to InfoWorld’s consultation with an Apple engineer at the event, over 500 networks were in operation at the same time.

    Yeah, that’s not Steve’s fault; that’ll cause problems no matter how magical your phone is. Still, if Apple’s public network had been up to snuff, people wouldn’t have been relying on MiFis in the first place. Public WiFi for 5,000 is a tall order, but it’s not impossible, PyCon 2010 even had a write-up of how they accomplished it.

  2. I really think they need to bring back the live broadcast of the keybotes. The reason so many MiFi networks were in place was the number of people liveblogging the event.

    They only liveblog the event because we want the info ASAP and there’s no other way to get.

    Even if they only offered live feeds to media folks not at the event, that could shut down a lot of the need the attendees feel for having internet access during the event. Have Ars (for example) send someone to the event, but have the commentary and photos be produced by someone not there and not hogging their spectrum.

  3. So it was chaos brought on by hundreds of people attempting to communicate without a shared system capable of supporting the load.

    The idea of disabling all unauthorized WiFi routers in the room and instead offering a seriously good Internet video feed to all media might be appealing to the organizers next time.

    They could achieve this simply by occupying all possible WiFi channels with their own APs, configured to occupy their radio channel continuously and never let go. Then the rogue APs would have no clear channel to use, and would (should) never activate themselves.

    1. You can’t just fill the channels: Wi-Fi devices aren’t required to avoid in-use channels entirely. It’s up to a manufacturer to choose a channel or to let it be set manually. There’s politeness, but there’s no rule about this, like first mover gets the channel. (This is true across Part 15 unlicensed spectrum, more or less, and similar rules outside the United States.)

      Also, they’re not “rogue APs.” I suppose Apple could declare MiFis and other devices offlimits, but then they’d be seizing gear or kicking out the press that’s covering the event.

  4. So why did one of his demo iPhones (the 3GS) connect to the NYT website while the new one failed multiple times?

    1. I have two suspicions about this.

      First, the iPhone 3GS uses 802.11g, and has less receive sensitivity than the iPhone 4, which supports 802.11n (only in 2.4 GHz). (I believe it’s 1×1 802.11n, which means it can’t make use of spatial diversity to help reduce “interference.” If it did, Steve wouldn’t have had the problem, most likely.)

      So the 802.11g might have been better at grabbing a slower signal and associating and coping with interference. (True, the iPhone 4 could step down to slower speeds and even use 802.11g, but I don’t know the precise mechanism.)

      Second, the iPhone 3GS might have gotten lucky, associated with a strong nearby AP signal, and kept it. The iPhone 4 might just not have been able to complete an association before the network went nuts, or it couldn’t grab one out of the noise.

  5. I wonder how many of those MiFi devices were used with iPhones. Because it would be a fun twist if AT&T’s famed inability to handle connectivity for large events pushed WWDC goers to bring their own wifi, thus fouling things up for Steve’s keynote. AT&T screws things up for Apple, yet again.

  6. I know it is uber sheik of late but I think it is ultimate rudeness to be typing while folks are speaking, even if they are live blogging. And you could almost feel the resistance from folks who had to and kept resisting to close down their laptops. i was at a play this weekend and floks were text messaging, distracting everyone.
    insane state of things..

    1. i was at a play this weekend and folks were text messaging

      People go to the play to watch the play. The point of the conference is to move product.

    2. uber sheik

      Uber Sheik? What’s that? Jamie Farr in “Cannonball Run?” That would be tres CHIC.

  7. What they should have done was have either a strong directional antenna covering the stage, and the stage only, or used one of the not legal for US use channels (up to 14 outside the US). Illegal, and you might have to have a hacked iphone, but that chunk of the spectrum would probably be clear.

  8. Why does a billionaire feel the need to “move product”?

    He had a near death experience and yet all he wants to do is spend his remaining years, “moving product” for a corporation now bigger than the dreaded Microsoft.

    Personally, I feel that being a billionaire is an obscenity that should be made illegal. And I’m no fan of plutocratic celebrities like Oprah, Gates, Buffet, Ellison, or Branson. But Jobs wins the title for the most bland and uncreative billionaire ever.

    1. Classifying Buffett with all those others just sort of shot down your entire argument.

    1. “Christ, what a bunch of a**********s”

      Starts with “a” ends with “s”. 12 letters.


      I give up.

  9. Hey – all 500 of you out there, tell me a story… all at the same time.

    Yes simultaneously! Oh, if you don’t think I am paying attention to you, start repeating those parts you think I missed it until you receive individual acknowledge from me that I’ve heard you.

    Welcome to WiFi! ;)

    WiFi is antiquated and nearly anarchy. Man would I like to see new non-legacy compatible WiFi iterations be adopted so we can get spectral efficiency and make the user experience better!

    What is the problem? WiFi was created to quickly and easily extend the wireless standard Ethernet, and now large ethernet installations don’t even use this shared wire installation any longer. They have switched over to ‘home run’ installations where each node has a connection directly to the router to increase efficiency.

    Unfortunately, with WiFi b,g,n there are only 3 non overlapping channels – 1,3 & 11. Add any of the other channels and they interfere with these!

    Can it be better? Yes!

  10. “Interference is really the limits of a radio to distinguish signals out of noise, not a physical property of radio waves”.

    Nonsense. Interference is due to the additivity properties of sine waves, which IS a physical property of radio waves.

    1. agger, as it is with waves and their frequencies, so it is with words and their meanings. For radio folk, interference is something else. If you want them to understand wave superposition, use the term fading.

    2. I don’t mean to be pedantic about interference, but there’s not a thing you can point to and measure that’s a physical quality called interference. Interference is an interpretation of the state of excitation of energy in a waveform and a receiver’s discrimination to extract information from it.

      Of course, you reach a point at which there’s no way within this universe to extract information; the information is lost because of the superposition of radio signals. But that’s not typically a situation when interference is cited. It’s the receiver, not the signal.

  11. What no one seems to be talking about is why didn’t they have a separate, private network on a different frequency for the demo?

    It seems so simple to me, perhaps I’m missing something?

  12. You could have set up a router with a MAC address with QoS for his little gem. Too technical, I suppose.

  13. What I find interesting about this whole thing is the difference in reaction between when it happened to Google and when it happened to Apple. With Google the story was treated slightly humoursly with some good natured ribbing. With Apple the reaction at best has been to question their competence and at worst to somehow claim it was a deliberate attack on bloggers.

    The bottom line is that until the last month of so it has been fine to demo wireless features by having a seperate wireless access point for the stage. Simple, effective and didn’t require hacking the device in any way. The advent of tethering and mifi like devices means those days are over. Google and Apple just found this out the hard way and will now adapt.

  14. I know it might be a little yesteryear (hell most current laptops I see in stores still have a VGA port and an ethernet port) but why not just cater to the livebloggers and give them all their own tethered ethernet cable at the chair? Then politely ask everyone to turn off wifi because 500 people using wireless at the same time screws with things. Problem solved…

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