563489578934

TABLE 8–2
CAPACITY OF PUBLIC-SWITCHED TELEPHONE NETWORKS
584
Transmission
Medium Name Developer
Year in
Service
Number of
Voice-
Frequency
Channels
Bit Rate
(Mbys)
Repeater
Spacing
(miles)
Operating
Frequency (MHz)
Modulation a
D>
A Method
Open-wire pair A Bell 1918 4 0.005–0.025 A FDM>
SSB
C Bell
CCITT
1924 3
12
150
50
0.005–0.030
0.036–0.140
A FDM>
SSB
J Bell 1938 12 50 0.036–0.143 A FDM>
SSB
CCITT 28 0.003–0.300 A FDM>
SSB
Twisted-pair K Bell 1938 12 17 0.012–0.060 A FDM>
SSB
cable
CCITT 12 19 0.012–0.060 A FDM>
SSB
N1 Bell 1950 12 0.044–0.260 A FDM>
SSB
N3 Bell 1964 24 0.172–0.268 A FDM>
SSB
T1 b Bell 1962 24 1.544 (DS-1) 1 D Bipolar
T1G b AT&T 1985 96 6.312 (DS-2) D Four-level
T2 b Bell 96 6.312 (DS-2) 2.3 D B6ZS
Coaxial cable L1 Bell 1941 600 8 0.006–2.79 A FDM>
SSB
L3 Bell 1953 1,860 4 0.312–8.28 A FDM>
SSB
L4 Bell 1967 3,600 2 0.564–17.55 A FDM>
SSB
L5 Bell 1974 10,800 1 3.12–60.5 A FDM>
SSB
T4 b Bell 4,032 274.176 (DS-4) 1 D Polar
T5 b Bell 8,064 560.16 (DS-5) 1 D Polar
Fiber-optic FT3 Bell 1981 672 44.763 (DS-3) 4.4 0.82 mm D TDM>
OOK
cable
Brit. Telcom 1984 140 6 1.3 mm D TDM>
OOK
Sask. Telcom 1985 45 6–18 0.84 and 1.3 mm D TDM>
OOK
F-400M Nippon 1985 400 12 1.3 mm D TDM>
OOK
FT3C-90 AT&T 1985 1,344 90.254 (DS-3C) 16 1.3 mm D TDM>
OOK
FT4E-432 AT&T 1986 6,048 432 (DS-432) 16 1.3 mm D TDM>
OOK
LaserNet Microtel 1985 6,048 417.79 (9DS-3) 25 1.3 mm D TDM>
OOK
FTG1.7 AT&T 1987 24,192 1,668 (36DS-3) 29 1.3 mm D TDM>
OOK
FT-2000 AT&T 1995 32,256 2,488 (OC-48) 100 1.5 and 1.3 mm D TDM>
OOK
WaveStar Lucent 1999 6,250,000 400,000 25 40 wavelengths D DWDM d
FlashWave Fujitsu 2002 27,500,000 1,760,000 176 wavelengths D DWDM
Transoceanic TAT-1 (SB) Bell 1956 48 20 0.024–0.168 A FDM>
SSB
TAT-3 (SD) Bell 1963 138 11 0.108–1.05 A FDM>
SSB
TAT-5 (SF) Bell 1970 845 6 0.564–5.88 A FDM>
SSB