Blog Update (October 26, 2008): Beware: T-Mobile's Voicemail Paging Trap

Blog Update (September 25, 2008 3:15 PM): T-Mobile Caves on 1 GB 3G Data Limit for HTC G1 Google Android Phone

Greetings. A couple of days ago I discussed the issue of T-Mobile's 1 GB limit on 3G data usage per billing cycle, after which extreme data speed throttling may be imposed. I also speculated that an unlocked HTC G1 Google Android phone running on AT&T's network instead of T-Mobile's might be quite a treat.

Unfortunately, it turns out that there's a catch. The G1 appears to be specifically designed -- at least in its current T-Mobile incarnation -- to be incompatible with AT&T's 3G network frequencies, which are different from T-Mobile's 3G configuration. Whether this could be changed strictly through firmware alterations is unclear at this time -- it appears doubtful.

An unlocked T-Mobile G1 could still operate in conventional GSM/GPRS/EDGE modes on the AT&T network, but the lower data speeds would obviously impact the user experience.

There is no obvious technical reason for such a limitation to be in place, so it seems reasonable to assume that it is a purposeful decision to discourage movement of the device between networks. Note that Apple's iPhone is in a similar situation -- it's tied to AT&T and its 3G frequencies are incompatible with T-Mobile 3G.

I still think that the G1 and Android look like a great combination, but if you're ever tempted by unlocked current versions of the G1 (or iPhone for that matter) and are thinking about moving them to the competing U.S. domestic 3G-capable network, keep in mind that 3G speeds will be out of reach, not by accident or technical necessity, but apparently purely by marketing design.

--Lauren--