VDict mobile



communications, standard (DECT, formerly ".. European ..") A
standard developed by the European TelecommunicationStandard Institute from 1988, governing pan-European digitalmobile telephony. DECT covers wireless PBXs, telepoint,
residential cordless telephones, wireless access to the
(CUGs), Local Area Networks, and wireless local loop.
DECT defines only the radio connection between two points and
can be used for remote access to public and private networks.
Other mobility standards, such as GSM, TACS, and DCS1800 add the necessary switching, signaling, and management
functions that are not specified by DECT.
The DECT Common Interface radio standard is a multicarrier
(MC-TDMA-TDD) radio transmission technique using ten radiofrequency channels from 1880 to 1930 MHz, each divided into
24 time slots of 10ms, and twelve full-duplex accesses per
carrier, for a total of 120 possible combinations.
A DECT base station (an RFP, Radio Fixed Part) can transmit
all 12 possible accesses (time slots) simultaneously by using
different frequencies or using only one frequency. All
signaling information is transmitted from the RFP within a
multiframe (16 frames). Voice signals are digitally encoded
into a 32 kbit/s signal using Adaptive Differential PulseCode Modulation.
The handover process is requested autonomously by the
portable terminal and the Radio Fixed Parts, according to the
carrier signal levels. A "Generic Access Profile" defines a
minimum set of requirements for the support of speech
telephony.
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(1999-04-13)