During Steve Jobs’ WWDC Keynote address last week, Apple’s CEO had trouble loading up a website during the iPhone 4 demo. A short while later, Jobs said that Apple figured out the problem and attributed it to the 500+ wi-fi base stations that filled up San Francisco’s Moscone Center.
Throughout the rest of the Keynote, Jobs periodically asked folks in the audience to turn off their mi-fi devices, or what have you, so that Jobs could showcase the iPhone 4’s new features without a hitch. You could tell that Jobs was particularly anxious/frustrated with wi-fi connectivity issues during his FaceTime demo with Johnny Ive as he said on more than one occasion, “FaceTime is great, especially when people shut off their wi-fi.”
Anywhoo, Ars Technica is now reporting that the connectivity issues experienced by Jobs may have had something to do with faulty iPhone 4 drivers.
However, after examining the video from the event and discussing it with two veteran WiFi gurus, it seems almost certain that the MiFi was only part of the problem. A flaw in the pre-release iPhone 4 iOS was clearly another element…
That’s not to say that having hundreds of WiFi base stations doesn’t cause trouble. In fact, the iPhone 4’s putative driver problem likely arose from the multitude of network signals. But neither the ocean of signals nor the iPhone 4’s performance can be looked at entirely in isolation.
After examining video of the wi-fi malfunction, Phil Kearney, who formerly headed up Apple’s networking group, was confident that he figured out the root of the problem. “My experience in the wireless space,” Kearney said, “leads me to believe that there may be a bug in the firmware or the driver for the WiFi chip in the iPhone 4.”
An obvious point, though, is that WWDC isn’t the only instance where hundreds of wi-fi base stations operate concurrently.
So what gives?
Glenn Fleishman, writing for Ars, explains that when thousands of base stations operate concurrently at places like Universities and music concerts, there typically exists a centralized management system to keep all the moving parts running smoothly, thereby ensuring that the various base stations play nicely together instead of competing for access.
The problem with huge numbers of uncoordinated base stations is that each is trying to carve out its own use, and each (along with associated devices) has to be only mildly respectful of all other WiFi gear in the same and even adjacent channels.
Without base station coordination, each network takes a hit because it doesn’t know precisely when a device on another network will start broadcasting. Get enough of those, and every device is backing off from talking, because it’s overlapping with someone else.
There’s a lot more technical and detailed information in the Ars article. It’s well worth a read.