An example of context was my playing with the GPS. I decided to see how well it would keep up with me driving at 160km/h (~100mph). Given the reports I was extremely happy to find that the little blue dot kept in place, correctly passing over-passes at the right time, for the whole 20 minute ride. The interesting thing was the streaming of the Google maps data. For the most part it streamed beautifully with the one exception… when you change cell towers the map streaming stopped altogether and I got a blue dot against a fast moving grey checker pattern until the new tower caught up with itself. Going back the other way a few days later confirmed this with the same dropouts in the same places (but in the other direction not to mention going much slower).

I don’t profess to know anything about UE/Node B interactions for voice and data but maybe the issues are a combination of factors which includes UE power management, AT&T’s immature 3G network along with the call context in some instances. Apple may be making updates in order to help cope with AT&T’s 3G rollout and their problems. This is not to say Apple is “blameless” (if there’s anything to point fingers over at all) here but it’s possible it’s not just the iPhone 3G.

1. The “calls dropped due to downlik power” occurs when the bases station exhusts all the power available to serve the active users, i.e. when it reaches the capacity. This can happen when there are too many active users at one time. Since iPhone clearly caused a spike in AT&T network load, this issue does not have anything to do with the iuPhone per se.

2. Phones are thoroughly tested by the operator before they are “accepted” into the network. The amount of power the phone sucks out of the network is of course one of the most important aspects of the testing. The phones caught “cheating” are not allowed into the service.

3. Power control works only for voice calls. For data calls, threre is no power control. The bases station spreads all the power left over from voice users across data users and the more power is available per data user the better throughput they will get.

It is more likely that there are more than one issue that were more tricky tha that and that could not be discovered durig the testing. This is very typical for a combination of a complicated techology, such as 3G, and an immature product, such as Infenion chipset. Think of it as a Beta version of Vista.