In trial a few months ago, the AT&T 3G MicroCell box is now ready to enter into service, nationwide. The basic purpose of this unit is to connect your 3G phone to the AT&T network in a better, more reliable way. It’s simple, voice and 3G data go from your phone to AT&T via this 2-way path: Phone <-> Microcell <-> Router <-> Internet <-> AT&T Network. What is happening is that you are bypassing the cellular tower completely and going directly to AT&T backbone infrastructure (providing relief to their wireless network at the same time). Those who have tested the unit have praised the lack of dropped calls and the quality of the connection. AT&T also offers unlimited talk time when calls go through the MicroCell. Of course, T-Mobile has UMA (T-Mobile Hotspot@Home), which works in a similar way, but AT&T’s MicroCell should be compatible with all AT&T 3G phones, while T-Mobile’s solution works only with a limited number of devices. UMA has the advantage to work with public WIFI hotspots, but it is not without problems either.
It’s not clear to me what would happen if you decided to take the box with you on an international trip. I’m fairly sure that it work just work, but I could not get AT&T to tell me if all the MicroCell calls would be free. In theory, AT&T doesn’t really care because they aren’t the ones paying for the voice data transport, the broadband internet provider is, but who knows… I’ve heard horror (billing) stories about T-Mobile’s UMA used abroad, so beware.
Unfortunately, the 3G Microcell is not yet perfect: a busy home network could disturb voice data and the range of the device appears to be limited in practice: 40-60feet, according to beta testers (AT&T claims that it will cover 5000sqft). If you have a poor reception at home, or if you want the unlimited minutes, check it out. Overall, I like the idea of MicroCell, and I think that AT&T should pursue this more aggresively by lowering the price. It helps AT&T as much as it helps you. For more information head to the 3G MicroCell official page.