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Guy Harris (talk | contribs) →3G systems: Perhaps the convention in India is that the middle name is part of the family name, but at least in the Anglosphere, it's not. |
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In radio systems, TDMA is usually used alongside [[frequency-division multiple access]] (FDMA) and frequency-division duplex (FDD); the combination is referred to as FDMA/TDMA/FDD. This is the case in both GSM and IS-136 for example. Exceptions to this include the [[DECT]] and [[Personal Handy-phone System]] (PHS) micro-cellular systems, [[UMTS-TDD]] UMTS variant, and China's [[TD-SCDMA]], which use time-division duplexing, where different time slots are allocated for the base station and handsets on the same frequency.
A major advantage of TDMA is that the radio part of the mobile only needs to listen and broadcast for its own time slot. For the rest of the time, the mobile can carry out measurements on the network, detecting surrounding transmitters on different frequencies. This allows safe
CDMA, by comparison, supports "soft hand-off" which allows a mobile phone to be in communication with up to 6 base stations simultaneously, a type of "same-frequency handover". The incoming packets are compared for quality, and the best one is selected. CDMA's "cell breathing" characteristic, where a terminal on the boundary of two congested cells will be unable to receive a clear signal, can often negate this advantage during peak periods.
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