CDMA , 2.5 - 2,5G.
() FDMA
( : NMT, AMPS .) - () TDMA ( : GSM, D-AMPS) , () CDMA -.
CDMA (Code Division Multiple Access) .
, . , . , , , .
. , , 1935 ...
CDMA , . 80- 1995. .
CDMA GPS.
CDMA DSSS -Direct Sequence Spread Spectrum - , () .
DSSS - , , .
, CDMA
CDMA, , .
CDMA2000 3G cdmaOne ( IS-95). , IS-95A, CDMA .
CDMA CDMA2000. CDMA2000 1,
153,0/, , , , , , . - CDMA2000 1xEV-DO 1,23, 2,4/ 153,0/ .
3G , . 1EV-DO Rev A, . 3,1/ MS ( ) 1,8/ MS. , Rev 0, , , , IP . . , 1EV-DO Rev B, : 4,9/ MS 2,4/ MS. . , 15- ( ) 73,5/ MS 27,0/ MS.
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CDMA - VoIP, Push to Talk, , , .
CDMA2000 : , ( ), . , , .
. , CDMA2000 250,0, GSM-900 2,0 ( ), GSM-1800 1,0 ( ).
CDMA
1G 2G () FDMA " " ("reuse") ().
, BTS .
"" ( - 7 ), BTS - ().
, BTS , . - (), BTS, .