Sources are telling us that AT&T is moving their older 2G EDGE platform over to the much weaker 1900MHz band to open additional room and space for its 3G HSPA platform. In effect, AT&T may be pushing those with older 2G devices into a position to have to upgrade sooner than they might have expected.

While AT&T has been quietly doing this for some time according to our sources, the result of moving 2G EDGE to the 1900MHz band will most certainly lead to worse performance and more spotty coverage, as the 1900MHz spectrum just isn’t as robust.

The move could have a major effect on those users that are still using older iPhones, as well as all BlackBerry devices, except the latest BlackBerry Bold offering from AT&T. Those lucky enough to have the latest generation of iPhone or the BlackBerry Bold that support 3G still may struggle, as many areas still have no 3G coverage and in some areas with 3G AT&T has spotty coverage, at best.

While users in the best blanketed major markets might not really feel the effect of this move, those in outlying areas are going to likely have to upgrade to a 3G device if 3G is supported in the area which could be considered as fringe by AT&T.

One of our sources has suggested to us that the move is necessary in preparation for the coming 4G roll outs and that while AT&T will not do away with EDGE at the time, it needs to move services around in the spectrum that it uses to make room. Over time, as users upgrade and get new phones these phones will support 3G as the primary connection for data services and users will be migrating off EDGE completely.

While we can’t argue that AT&T needs to upgrade its data services, one would think that it would first work hard to get more 3G coverage rolled out and shore up the performance of the 3G in the majority of the markets before starting to move customers over to 3G. As far as we can tell, the majority of the AT&T customers are using EDGE, and the decision to weaken the EDGE coverage will likely result in at least some backlash from customers unhappy with the weaker coverage and worse performance.