I'll appreciate of someone would clarify the nomenclature issue for UMTS phones/service please. From what I have read, T-mobile's 3G service uplinks in 1.7 GHz band and downlinks in 2.1 GHz. Shouldn't T-mobile's phones be operable in both 1.7 GHz and 2.1 GHz bands? Some of T-mobile's phones are said to have 1.7 GHz band but not 2.1 GHz!
The only explanation that comes to mind is that although the phone is said to operate nominally in 1.7 GHz band, it does have the capability to work with 2.1 Ghz downlinks.

If the uplink band is used in nomenclature although the phone also works in the downlink band, why are UMTS phones in Europe said to operate in 2.1 GHz band (which is the downlink band)?

Why can't we be consistent about nomenclature?