UMTS stands for Universal Mobile Telecommunications System. It is a group of radio technologies that are used for third-generation (3G) cellular networks. UMTS provides faster and more reliable data transmission than the previous 2G networks, such as GSM, GPRS, and EDGE.
UMTS works by using a wideband code-division multiple access (WCDMA) radio access technology, which allows multiple users to share the same frequency channel by using different codes. UMTS also uses a core network that is based on the GSM standard, but with some enhancements to support packet-switched and circuit-switched services. UMTS can offer data rates up to 42 Mbps with the use of advanced technologies, such as HSPA and HSPA+.