Universal Mobile Telecommunication System (UMTS)
UMTS frequency allocation

The operational frequency bands of UMTS system is set to be around 2 GHz, which still ensures reasonable transmission characteristics, low signal attenuation and easy signal penetration to indoor environment. The assigned frequency bands depend whether UMTS works in so called Time Division Duplex (TDD) or in Frequency Division Duplex (FDD).

The UMTS can be used for operation with a minimum spectrum of 2 x 5 MHz for paired frequency band assigned for UMTS FDD and 5 MHz for unpaired frequency band dedicated for UMTS TDD. The assigned frequency bands are somewhat different for Europe and USA. In Europe, UMTS TDD has allocated frequency bands in region of 1900-1920 MHz for uplink and in region of 2010-2025 MHz for downlink. The UMTS FDD has allocated much wider bands due to the fact that FDD is supposed to be used preferably. Regarding the uplink direction, frequency bands varying from 1920-1980 MHz are allocated. On the other hand, frequency bands between 2110-2170 MHz are assigned for downlink.

The reason why uplink frequency bands are located at lower frequency than downlink is due to limited power and battery limitations of mobile terminals. The lower frequency bands are characterized by lower signal attenuation. Consequently, the coverage in uplink can be easily guaranteed while the transmission power of mobile terminals can remain at reasonable value. Note that maximal transmission power of base station is usually 43-46 dBm, while transmission power of mobile terminal is usually up to 23 dBm.