UMTS Terrestrial Radio Access - the UMTS radio standard defines UTRAN, the UTRA RAN (Radio Access Network) for UMTS. Terrestrial as distinct from satellite-based. UTRA uses BPSK and QPSK modulation with WCDMA for multiple access, in contrast to GSM which uses GMSK and TDMA. See also EDGE, which delivers higher data rates within the GSM TDMA structure.
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