l Nyquists Theorem Max data rate Noiseless Channel

ﺣﺪﺍکﺜﺮ ﻧﺮﺥ ﺍﺭﺳﺎﻝ کﺎﻧﺎﻝ l Nyquist’s Theorem Max. data rate = (Noiseless Channel) l where V represent No. of discrete level of signals. Shannon’s Theorem Max. data rate = (Noisy Channel) where S/N represent signal-to-noise ratio. 11

Signal + noise Noise High SNR Noise Signal + noise Low SNR t t SNR = t t Average signal power Average noise power SNR (d. B) = 10 log 10 SNR Figure 3. 11 12

(Twisted Pair) ﺯﻭﺝ ﺑﻪ ﻫﻢ ﺗﺎﺑیﺪﻩ (a) Category 3 Unshielded Twisted Pair (UTP). BW. =16 MHz (b) Category 5 Unshielded Twisted Pair (UTP). BW. =100 MHz (c) Cat. 6 BW. =250 MHz, Cat. 7 BW. = 600 MHz 16

Physical Media Shielded Twisted Pair (STP)

Unshielded Twisted Pair (UTP) 18

Coaxial Cable 19

Coaxial Cable (2) l Coaxial cable (coax) – – – better shielding longer distances at higher speeds two kinds • • l Bandwidth – l 50 -ohm cable: digital transmission 75 -ohm cable: analog transmission 1 -km cable: 1 -2 Gbps Application – – telephones system: coaxial cable are being replaced by fiber optics widely used for cable TV 20

Ray description of different fibers

ﻋﻤﻠکﺮﺩ ﻣﻮﺩﻡ ﺗﺒﺪیﻞ ﺳیگﻨﺎﻝ ﺩیﺠیﺘﺎﻝ ﺑﻪ ﺳیگﻨﺎﻝ آﻨﺎﻟﻮگ (a) A binary signal (b) Amplitude modulation (c) Frequency modulation (d) Phase modulation 24

ﺗﺴﻬیﻢ ﺳﺎﺯی ﻓﺮکﺎﻧﺲ Frequency Division Multiplexing (FDM) (a) The original bandwidths. (b) The bandwidths raised in frequency. (c) The multiplexed channel. 28

ﺗﺴﻬیﻢ ﺳﺎﺯی ﺯﻣﺎﻧی Time Division Multiplexing (TDM) Pulse Code Modulation (PCM) is the heart of the modern telephone system l A analog signal is sampled, quantized and coded l Each channel has 8 bits, 24 channels and one framing bit form a frame of 125 µsec The T 1 carrier (1. 544 Mbps). 29

ﺗﺴﻬیﻢ ﺳﺎﺯی پﻬﻨﺎی ﺑﺎﻧﺪ Wavelength Division Multiplexing (WDM) 30

FDM ﻭ TDM ﺳﻮﺋیچیﻨگ ﻣﺪﺍﺭی ﺑﺎ ﺍﺳﺘﻔﺎﺩﻩ ﺍﺯ Example: FDM 4 users frequency time TDM frequency time 31

SONET STS-1 frame 90 columns 9 rows framing Synchronous Transfer Signals are bit-signals (OC are optical) n n n Each STS-1 frame is 90 columns * 9 rows = 810 bytes There are 8000 STS-1 frames per second Thus the basic STS-1 rate is 51. 840 Mbps

SONET/SDH rates l The Synchronous Transport signal-1 (STS-1) is the basic SONET channel l The Optical carrier (OC) corresponding to STS-n is called OC-n SONET and SDH multiplex rates. 34

Network Connection Speeds Reference (link) Name Analog POTS Modem ITU V. 21 ITU V. 22 bis ITU V. 29/V. 32 Facsimile (Fax) Cellular Digital Packet Data (CDPD) ITU V. 32 bis HSCSD ITU V. 34 (V. fast) ITU V. 90 T-0/E-0/J-0/DS-0 (1 Voice Channel) N-ISDN (Narrowband) Fractional T-1 (64 kbps Increments) GPRS ISDN BRI (Basic Rate 2 B+D, B = 64 kbps, D = 16 kbps) EDGE Bluetooth Speed 300 bps - 56. 7 kbps 300 bps 1. 2 kbps 2. 4 kbps 9. 6 - 14. 4 kbps 28. 8 - 56. 0 kbps 33. 6 kbps 56. 0 kbps 64. 0 kbps - 1. 544 Mbps 114 kbps 144 kbps 384 kbps 723 kbps 35

Network Connection Speeds Reference (link) Name Star. LAN ISDN PRI (Primary Rate 23 B+D, B = 64 kbps, D = 64 kbps) T-1/J-1 (24 Voice Channels) WCDMA/WTDMA E-1 (30 Voice, 2 Control(64 kbps) Channels) ARCnet T-1 C/J-1 C (2 T-1/J-1) UMTS Token Ring T-2/J-2 (4 T-1/J-1) E-2 (4 E-1) Ethernet 10 Base-X 802. 11 b (Wi. Fi) Fast Token Ring J-3 (20 J-1) E-3 (16 E-1) T-3 (28 T-1) OC-1/STS-1 Speed 1 Mbps 1. 544 Mbps 2. 048 Mbps 2. 5 Mbps 3. 152 Mbps 3. 5 Mbps 4 Mbps 6. 312/6. 443 Mbps ** 8. 448 Mbps 10 Mbps 11 Mbps 16 Mbps 32. 064 Mbps 34. 368 Mbps 44. 736 Mbps 51. 84 Mbps 36

Network Connection Speeds Reference (link) Name 802. 11 a/g T-3 C (56 T-1) J-3 C (60 J-1) Fast Ethernet 100 Base-X 100 VG Anylan High Speed Token Ring FDDI/CDDI TS-3 D/DS-3 D E-4 (64 E-1) ATM* OC-3/STS-3/STM-1 T-4 (168 T-1) J-4 (240 J-1) OC-9/STS-9/STM-3 E-5 (256 E-1) ATM* OC-12/STS-12/STM-4 OC-18/STS-18/STM-6 Gigabit Ethernet 1000 Base-X Speed 54 Mbps 89. 472 Mbps 97. 728 Mbps 100 Mbps 135 Mbps 139. 264 Mbps 155. 52 Mbps 274. 176 Mbps 397. 200 Mbps 466. 56 Mbps 565. 148 Mbps 622. 08 Mbps 933. 12 Mbps 1 Gbps 37

Network Connection Speeds Reference (link) Name OC-24/STS-24/STM-8 OC-36/STS-36/STM-12 OC-48/STM-16 OC-96/STS-96/STM-32 OC-192/STS-192/STM-64 10 Gigabit Ethernet WAN 10 Gigabit Ethernet LAN OC-256/STS-256 OC-384/STS-384/STM-128 OC-768/STS-768/STM-256 OC-1536/STS-1536/STM-512 OC-3072/STS-3072/STM-1024 Speed 1. 24416 Gbps 1. 86624 Gbps 2. 48832 Gbps 4. 97664 Gbps 9. 95328 Gbps 10 Gbps 13. 27104 Gbps 19. 90656 Gbps 39. 81312 Gbps 79. 62624 Gbps 159. 25248 Gbps OC-X: X refers to the Optical Carrier Level, from North American SONET (ANSI) STS-X: X refers to the Electrical Carrier Level, from North American SONET (ANSI) STM-X: X refers to the International SDH (Synchronous Digital Hierachy) Level (ITU-T) 38