And if Apple is trying to avoid an exclusive deal with this expected launch, Gold said he also wondered why the tablet wouldn't work on more than two carriers in the U.S., since T-Mobile USA runs a separate 3G network based on GSM.

The proposition that more than one carrier could support the Apple tablet suggests there will some kind of competition for throughput, or speed, a user gets. Most measurements of speeds are based on averages over broad areas, and don't account for individual differences, including whether a nearby cell tower is congested with many users or near tall buildings and other obstructions, analysts noted.

AT&T Mobility CEO Ralph de la Vega said in December that the carrier was having , where networks performed "below standards." In San Francisco's financial district, for example, antennas needed to be replaced, he noted.

On a broader basis, Verizon has also established a larger area of coverage for 3G wireless in the U.S than AT&T, an . AT&T has responded with its own ads, making note of greater variety of network capabilities for its users.

De la Vega has described a series of network buildouts that include moving to , to be installed in 25 cities by mid-2010. Asked today about the status of six cities that were due to be activated with HSPA 7.2 by now, however, the AT&T spokesman would not comment.