UMTS-TDD, an acronym for
Universal Mobile Telecommunications System (UMTS) - time-division duplexing (TDD), is a
3GPP standardized version of
UMTS networks that use
UTRA-TDD. UTRA-TDD is a
UTRA that uses
time-division duplexing for
duplex. While a full implementation of UMTS, it is mainly used to provide Internet access in circumstances similar to those where
WiMAX might be used. UMTS-TDD is not directly compatible with UMTS: a device designed to use one standard cannot, unless specifically designed to, work on the other, because of the difference in air interface technologies and frequencies used.
UTRA-TDD HCR
UTRA-TDD HCR is one of the air interfaces used for UMTS-TDD. It uses increments of 5 MHz of spectrum, with each slice divided into 10ms frames containing fifteen time slots (1500 per second). The time slots are allocated in fixed percentage for downlink and uplink.
TD-CDMA is used to multiplex streams from or to multiple transceivers.
UTRA-TDD LCR
UTRA-TDD LCR is an alternative air interface used for UMTS-TDD. It is based on
TD-SCDMA, and uses 1.6 MHz slices of spectrum, and is standardized in UMTS by the 3GPP.
Unlicensed UMTS-TDD
In Europe,
CEPT allocated the 2010-2020 MHz range for a variant of UMTS-TDD designed for unlicensed, self-provided use. Some telecom groups and jurisdictions have proposed...
Read More