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Review of last lecture Select Repeat ARQ Performance of different ARQ schemes Data link layer -- framing HDLC PPP. ELEN 602 Lecture 7. Multiplexing. (a). (b). A. A. A. A. Trunk group. B. B. B. MUX. MUX. B. C. C. C. C. A. f. W. 0. B. f. 0. W. C. B. A. f. C.
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Review of last lecture Select Repeat ARQ Performance of different ARQ schemes Data link layer -- framing HDLC PPP ELEN 602 Lecture 7
Multiplexing (a) (b) A A A A Trunk group B B B MUX MUX B C C C C
A f W 0 B f 0 W C B A f C f 0 W Frequency Division Multiplexing (a) Individual signals occupy W Hz (b) Combined signal fits into channel bandwidth
(a) Each signal transmits 1 unit every 3T seconds A1 A2 t 0T 6T 3T B1 B2 t 6T 3T 0T C1 C2 t 0T 6T 3T 0T 1T 2T 3T 4T 5T 6T A2 B2 B1 C1 C2 A1 t Time-division Multiplexing (b) Combined signal transmits 1 unit every T seconds
T-1 Carrier System 1 1 2 MUX MUX 2 . . . . . . 22 23 24 1 b 24 2 b . . . frame 24 24
Primary Multiplex Eg. Digital Switch 24 chan PCM M23 Multiplex x7 M12 Multiplex x4 DS2 6.312 Mbps DS3 44.736 Mbps DS1 1.544 Mbps 1 M13 Multiplex DS3 44.736 Mbps 28 Basic Digital Hierarchy North American Digital Hierarchy
Timing in TDM Multiplexer t 5 4 3 2 1 5 4 3 2 1
SONET Multiplexing DS1 Low-Speed Mapping Function DS2 STS-1 CEPT-1 51.84 Mbps DS3 Medium Speed Mapping Function STS-1 44.736 OC-n STS-n STS-3c STS-1 Mux E/O Scrambler CEPT-4 High- Speed Mapping Function STS-1 STS-1 139.264 STS-3c STS-1 STS-1 High- Speed Mapping Function ATM STS-1 150 Mbps
DEMUX DEMUX MUX MUX SONET add-drop multiplexing (a) pre-SONET multiplexing insert tributary remove tributary (b) SONET Add-Drop multiplexing ADM DEMUX MUX insert tributary remove tributary
a OC-3n OC-3n b 3 ADMs c OC-3n physical loop net SONET Ring Network
a a OC-3n OC-3n b c b c OC-3n logical fully-connected net 3 ADMs connected in physical ring topology Logical Networks (b) (a)
a a b b d d c c Surviving Faults in SONET (a) Dual ring (b) Loop-around in response to fault
Regional Ring Metro Ring Inter-Office Rings SONET Network Structure
Wavelength Division Multiplexing Optical MUX Optical deMUX 1 1 2 1 2 2. m Optical fiber m m
(a) WDM chain network c b d a Network Configuration using WDM (b) WDM ring network a 3 ADMs b c