On to the next rant. It turns out that the frustration with the iPads was two-fold. First, as users moved throughout the building with their iPads, they would sometimes jump from our secure production network to a dead-end configuration SSID. The effect is quite disruptive, but, thankfully, easy to replicate with my own iPad. The short version: The iPads were being "sticky clients," not letting go of the AP they started on in favor of the next one they should go to.
This behavior is strictly client-driven, and was sometimes compounded by the device selecting the first network listed in its "available networks" list, which is our dead-end configuration WLAN. To the frustrated user, the WLAN itself was "pushing" them to the wrong network. In reality, the devices just weren't roaming well, despite pretty much every other wireless platform doing just fine changing access points in the same environment. It's no fun explaining the theory of operation of the 802.11 standard to executives who just want things to work. But there's only so much you can do on a standards-based WLAN.
The second iPad problem also affected iPhone users. The devices were randomly rebooting throughout the course of the day, and at very inopportune times. For one exec, it happened when checking e-mail on the iPad; for another, it happened during voice calls on the iPhone. Both devices also happened to be on AT&T, and there are plenty of Web gripes about this same condition. But again, to the users, the WLAN is suspect, because one misinterpreted issue is easy to attach to another when you don't know better. A support ticket to Apple resulted in, "...uh, yeah--you should probably upgrade your code for that problem on those devices."
Back home after the road trip, a student employee who was testing the new iPhone Personal Hotspot came into my office, looking a bit pained. His concern? The Hotspot came up nicely, but on Channel 2. Anyone who knows wireless knows that any channel in the 2.4GHz band other than 1, 6 and 11 is cause for alarm.
It very much appears that the Personal Hotspot channel cannot be changed in the iPhone settings, resulting in degraded performance for Channels 1 and 6 that may overlap with this cell. (I did find in research that the the Verizon Mi-Fi has a selectable channel). In my environment, we have policy that disallows the use of these portable hotspots, but whether by intent or ignorance the policy will be violated on occasion, and our dense Wi-Fi deployment will suffer a bit because of this "feature." I have no idea whether all iPhone Personal Hotspots go to different channels, but I know that the lack of manual channel selection means that there is no regard for impact on an enterprise WLAN.
