(
Universal
Mobile
Telecommunications
System) The standards for the 3G evolution of the GSM cellular system. Also called "3GSM," UMTS is part of the 3GPP project and the ITU's IMT-2000 families of 3G standards. UMTS embraces the FOMA, WCDMA and HSPA air interface technologies, and UMTS networks can co-exist with earlier GSM (GPRS and EDGE) networks. With service in the 2 GHz band, UMTS offers global roaming and personalized features. See
3GPP,
HSPA,
cellular generations,
IMT-2000,
WCDMA and
LTE.
3G/UMTS and 2.5G EDGE
Using the GSM cellular system, a smartphone can switch between the slower EDGE network and the faster 3G UMTS network.