While many other countries around the world have generally harmonized the radio spectrum they use for mobile phones, the US has generally marched to its own beat. This was again the case with last year’s AWS spectrum auction, covering licenses for the 1700 and 2100 MHz bands, in which AT&T (NYSE: T) and T-Mobile both won licenses. Because the frequencies differ from those used for 3G in other parts of the world, a limited number of compatible handsets have been made by vendors. However, that could be set to change, as several other countries in the Americas are preparing to auction or allocate the 1700/2100 band for 3G services, says 3G Americas, the trade group for GSM in the Americas (via Phone Scoop). Canada and Chile will auction licenses for the band in the first half of 2008, with Mexico’s auction scheduled in July; Argentina, Colombia and Ecuador have also reserved it for mobile communications. While this trend remains far short of global spectrum harmonization and device compatibility, it should help ensure a steady stream of compatible 3G devices are available in the US.