http://en.wikipedia.org/wiki/UMTS_frequency_bands#UMTS-FDD http://en.wikipedia.org/wiki/UMTS_frequency_bands#UMTS-FDD (scroll up slightly from there to see the

http://en.wikipedia.org/wiki/UMTS_frequency_bands#UMTS-FDD http://en.wikipedia.org/wiki/UMTS_frequency_bands#UMTS-FDD (scroll up slightly from there to see the five "major" UMTS bands identified. NOTE: GSM/EDGE band support is different from UMTS band support. Except where explicitly stated, the rest of this is about UMTS bands. Band IV is T-Mobile USA's high speed data band. Bands II and V are AT&T's high speed data bands. The Galaxy Nexus has bands I, II, IV, V, VIII http://www.phonearena.com/phones/Samsung-GALAXY-Nexus_id5595 http://www.phonearena.com/phones/Samsung-GALAXY-Nexus_id5595 iPhones (the GSM versions, not the Verizon versions) omit band IV, so they won't work on T-Mobile USA's UMTS data network. T-mobile phones typically (and varyingly) omit bands II, V, and/or VIII. I suggest searching phonearena for a handful of modern phones and comparing the supported GSM (& EDGE) bands (where most/all smartphones are quad-band) and UMTS bands (where supported bands are much more varying).