Universal Mobile Telecommunications System

UMTS (Universal Mobile Telecommunications System) — Universal Mobile Telecommunications System — is a high-speed packet data transmission technology for mobile communications. It is a third generation mobile communication network standard (3G networks) based on the W-CDMA broadband data transmission technology with code division multiple access. Developed by the European Telecommunications Standards Institute (ETSI) for the deployment of 3G in Europe.

For radio channel data transmission, the W-CDMA technology is used, standardized according to the 3GPP project. UMTS uses the GSM network infrastructure; however, the UMTS-based radio access network is completely different and consists of other components.

To distinguish it from competing solutions, the UMTS standard is also often referred to as 3GSM, in order to emphasize its affiliation with 3G networks and its technological continuity with GSM standard networks.

UMTS provides a theoretical data transfer rate of up to 21 Mbit/s (when using HSPA+). Currently, the highest practical speeds are considered to be 384 kbit/s for R99 technology mobile stations and 7.2 Mbit/s for HSDPA stations in the downlink from the base station to the mobile terminal.

The UMTS technology enables soft handover, allowing the subscriber to be seamlessly transferred between multiple base stations. UMTS mobile communication is protected from connection drops while in motion, as soft handover is used. As the subscriber moves away from one base station, another “takes over,” gradually transmitting more and more data, while the first station transmits less and less, until the subscriber leaves its coverage area entirely. The connection is not interrupted abruptly, as may occur in GSM networks.

UMTS mobile networks can establish connections with various external networks, conventionally divided into two groups: circuit-switched and packet-switched. The first type is intended for voice telephony, and the second for Internet access.

Data rate requirements for the UMTS standard:

• At subscriber speeds up to 500 km/h outside large cities – up to 384 kbit/s (but not less than 144 kbit/s);

• At subscriber speeds up to 120 km/h within urban or suburban areas – up to 512 kbit/s (but not less than 384 kbit/s);

• At speeds up to 10 km/h indoors – at least 2 Mbit/s.

GSM-900 frequencies, GSM-1800 frequencies, Radio frequency spectrum, GSM