UMTS (Universal Mobile Telecommunications System) is a so-called "third-generation (3G)" broadband,  packet -based transmission of text, digitized voice, video, and multimedia at data rates up to and possibly higher than 2 megabits per second ( Mbps ), offering a consistent set of services to mobile computer and phone users no matter where they are located in the world. Based on the Global System for Mobile (GSM) communication standard, UMTS, endorsed by major standards bodies and manufacturers, is the planned standard for mobile users around the world by 2002. Once UMTS is fully implemented, computer and phone users can be constantly attached to the internet as they travel and, as they roaming service, have the same set of capabilities no matter where they travel to.

Source: www.whatis.techtarget.com