() CDMA , () TDMA, FDMA - ().
, MS, BTS, "" MS, CDMA , MS BTS , , .
CDMA " " BTS ("soft handoff"). , MS "" BTS.
, "" BTS. , BTS.
GPS - Global Positioning System - ().
CDMA - , .. , " " () , , .
, .
CDMA (, , ) .
() - TDMA.
CDMA: , , , , .
() CDMA
, CDMA .
IS-95 (800,0) CDMA PCS (1900,0).
, CDMA - .
CDMA, , .
C CDMA , CDMA 14,4/, IP.2,0 . , CDMA .
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.
CDMA 144,0/.
, , , .
CDMA Development Group () , 300,0/, CDMA - 3G.
CDMA - 3G - () TDMA.
TIA / EIA (Telecommunication Industry Association / Electronic Industries Alliance) CDMA 2000 (é :IS-2000), é IS-95.
CDMA 2000 -
CDMA One (CDMA + CDMA 800) - 1,0/÷1,5/. . IS-95.
, CDMA 2000 é IS-95, CDMA 2000 IS-95. , - " soft handoff " (" " , ) CDMA 2000 IS-95.
, , IS-95 CDMA 2000 .
CDMA 2000 , , , Band Class 5 (NMT-450) - 1G - 3G, CDMA 2000, . CDMA 2000 . AMPS, , .
CDMA 2000 " " - International Mobile Telecommunications - IMT 2000, ITU (International Telecommunication Union, -) 3G, , .
- TDMA ( IS-136 IMT-2000) CDMA , GSM - () -TDMA.
CDMA 2000 , ,
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IMT-2000, 384,0/, 320240.
CDMA
CDMA .
, CDMA " " "" .
- CDMA - , , , MS , . .
. - , . , CDMA .
- CDMA. , .
, BTS , , , "" , BTS , .. BTS MS.
BTS BTS , (, ). .
- BTS - GPS. GPS , .. "soft handoff" (" " LA ) BTS.
, 800,0, CDMA, - - , "" .
, , , , . : - CDMA - Code Division Multiple Access, , NMT, AMPS , , , GSM.
() CDMA :
. , - , - .. (: 0,3 - 3,4), , , , .
CDMA: BTS MS , , , , , . CDMA .
GSM, TDMA - Time Division Multiple Access - (), .. , CDMA, CDMA, .
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CDMA , - .
CDMA2000 - 1,5/ .
- , , ( , ).
CDMA - , - .
D-AMPS , , , CDMA .
CDMA , AMPS. CDMA,
D-AMPS 120 , , , , , BTS, .
D-AMPS ( , , ), CDMA . , , 1,25, CDMA , D-AMPS.
, . . , , . , . , , .
, - fading.
MS LA : " " (hard handoff), .
, , : , .
CDMA , , FDMA TDMA. :
- -, CDMA - ( " ", .. , CDMA),
- -, CDMA ( 1,5/).
, .
, CDMA , () . .
"" , .
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- , () . ( ): .
. , .
, CDMA MS, .. .
MS , BTS, ( ).
CDMA , MS .
" " (hard handoff break before make) , , CDMA " " (soft handoff make before break): MS BTS, , . , , .
MS, , BTS .
BTS - - MS , BTS. , .
CDMA , , - . , . , , , , . , CDMA .
, . , .
, .
CDMA
- . 1994 . ( IS-95), CDMA , .
, , .
QUALCOMM, Samsung, Motorola, Lucent Technologies, Nortel . , , .
" ".
, MS BTS, - make before break , , .
CDMA : - " " (Wireless Local Loop - WLL), "" , .
CDMA , .
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, " " - .
CDMA 1900,0 - PCS - Personal Communications Services - .
PCS: . PCS , , .
PCS - CDMA, , ( , , CDMA "", ), . PCS CDMA.
CDMA D-AMPS , .
CDMA é , D-AMPS.
, , , , , .
CDMA
Code Division Multiple Access - ().
CDMA- . .
- . , , . 1,25. 8,55/, 1,2/. CDMA , MS, MS , .
CDMA One
CDMA One, IS-95a, IS-95b (cellular - - 800,0) PCS ( - 1900,0).
IS - Interim Standard - , TIA - Telecommunications Industry Association.
, CDMA One IS-95a, 9,6/ ( ) 14,4 / ( ).
IS-95b CDMA, ( ). 28,8 / ( 14,4/) 115,2 / (8 14,4/).
IS-95 CDMA One . CDMA One 1995 .
CDMA One "CDMA" "CDMA-800" ( 800- , IS-95). 869,040-893,970 824,040-848,860.
64 1,25.
- NMT GSM . , 800,0 . "" N-AMPS, D-AMPS CDMA.
, , -800 "" x-AMPS GSM 1800. CDMA IS-95 , - .
W-CDMA
W-CDMA - Wideband Code Division Multiple Access - CDMA - ( 1988 ) ETSI (European Telecommunications Standards Institute) .
W-CDMA , ; 2,048/ 384,0/ - MS. , W-CDMA 5,0.
GSM PDC, W-CDMA .
W-CDMA - () , . - 3G, , GSM. W-CDMA , , 2,048/ ( ) 384,0/ ( 120,0/). W-CDMA GSM UMTS.
CDMA 2000
CDMA 2000 2G CDMA One, IS-95c, .
, Qualcomm ITU, CDMA 2000. Lucent Technologies IS-2000. - :
- IMT-2000 (International Mobile Telecommunications System - 2000 - - 2000),
- IMT-MC (Multi Carrier)- CDMA 2000, CDMA One (IS-95).
- IMT-DS (Direct Spread) - W-CDMA UMTS.
CDMA 2000 3G, .. . 2.5G.
CDMA2000 (IMT-MC) - 1X 2X. IS-95. 1X-EV (evolution), - CDMA2000 1X EV-DO (data only) CDMA2000 1X EV-DV (data & voice).
CDMA 2000 , CDMA (450, 700, 800, 900, 1700, 1800, 1900).