Embed Size (px)
Citation preview
COMMUNICATIONS ISSUESCOMMUNICATIONS ISSUES
Professor Saad Haj Bakry, PhD, CEng, FIEEProfessor Saad Haj Bakry, PhD, CEng, FIEE
NETWORK ARCHITECTURENETWORK ARCHITECTURE
CONTENTSCONTENTS
Saad Haj Bakry
Network ArchitectureCommunications Issues
SIGNALSSIGNALS
MODULATIONMODULATION
CHANNELS
CHANNELS
FLOWFLOW
SUGGESTED WORKSUGGESTED WORK
SIGNALSSIGNALS
Saad Haj Bakry
Network Architecture
SIGNALS CHARACTERISTICSSIGNALS CHARACTERISTICS
FOURIER EXPANSIONFOURIER EXPANSION
NOISENOISE
SINUSOIDAL SIGNALSSINUSOIDAL SIGNALS
Communications Issues / Signals
FOURIER TRANSFORMFOURIER TRANSFORM
FREQUENCY SPECTRUMFREQUENCY SPECTRUM
INFORMATION SIGNALSINFORMATION SIGNALS
RATIOS: dB RATIOS: dB
BAUD V (bps) BAUD V (bps)
DIGITAL SIGNALSDIGITAL SIGNALS
FREQUENCY TRANSLATIONFREQUENCY TRANSLATION
SIGNAL CHARACTERISTICSSIGNAL CHARACTERISTICS
OBJECTIVES: Represent Information (Voice / Data / Image)
Perform a Task (Signalling / RADAR)
OBJECTIVES: Represent Information (Voice / Data / Image)
Perform a Task (Signalling / RADAR)
Saad Haj Bakry
Network Architecture Communications Issues / Signals
FORMS: Analog / Digital
FORMS: Analog / Digital
DOMAINS: Time / Frequency
DOMAINS: Time / Frequency
TIMING: Periodic / Non-Periodic
TIMING: Periodic / Non-Periodic
NATURE: Electrical / Light
NATURE: Electrical / Light
FOURIER EXPANSION FOURIER EXPANSION
OBJECTIVES: To Represent
“Periodic Signals” by Simpler Components
to Ease Analysis
OBJECTIVES: To Represent
“Periodic Signals” by Simpler Components
to Ease Analysis
Saad Haj Bakry
Network Architecture Communications Issues / Signals
FINITE BANDWIDTH: Considers “Significant” Components
FINITE BANDWIDTH: Considers “Significant” Components
RESULT: An “Infinite” Set of
“Harmonic” Sinusoidal Signals and a Constant
RESULT: An “Infinite” Set of
“Harmonic” Sinusoidal Signals and a Constant
FOURIER TRANSFORM FOURIER TRANSFORM
OBJECTIVES: To Transform “Non-
Periodic Signals” from the Time Domain to the
Frequency Domain (and Vice Versa) to Enable Flexible
Signal Analysis
OBJECTIVES: To Transform “Non-
Periodic Signals” from the Time Domain to the
Frequency Domain (and Vice Versa) to Enable Flexible
Signal AnalysisSaad Haj Bakry
Network Architecture Communications Issues / Signals
RESULTS: The Frequency Function has an “Infinite Range”
RESULTS: The Frequency Function has an “Infinite Range”
FINITE BANDWIDTH: Considers
“Significant” Frequency Components
FINITE BANDWIDTH: Considers
“Significant” Frequency Components
SINUSOIDAL SIGNALS SINUSOIDAL SIGNALS
PERIODIC:
T (sec)
PERIODIC:
T (sec)
Saad Haj Bakry
Network Architecture Communications Issues / Signals
WAVE
LENGTH:
L (met) = V.T = V / F
WAVE
LENGTH:
L (met) = V.T = V / F
IMPORTANCE
: Harmonic Components of Signals / Modulation
IMPORTANCE
: Harmonic Components of Signals / Modulation
FREQUENCY:
F (Hz) = 1 / T
FREQUENCY:
F (Hz) = 1 / T
VELOCITY:
V (met / sec)
VELOCITY:
V (met / sec)
AMPLITUDE: A (vol)
AMPLITUDE: A (vol)
EFFECTIVE VALUE:
U(vol) = A / sqrt(2) NORMALIZED POWER:
S (wat) = A2 / 2
EFFECTIVE VALUE:
U(vol) = A / sqrt(2) NORMALIZED POWER:
S (wat) = A2 / 2
FREQUENCY SPECTRUM: 1/4 FREQUENCY SPECTRUM: 1/4
Saad Haj Bakry
Network Architecture Communications Issues / Signals
VLF: 3 kHz - 30 kHz
(100 km - 10 km)
VLF: 3 kHz - 30 kHz
(100 km - 10 km)
HF: 3 MHz - 30 MHz
(100 m - 10 m) Telephone / Ships / Airplanes
HF: 3 MHz - 30 MHz
(100 m - 10 m) Telephone / Ships / Airplanes
LF: 30 kHz - 300 kHz (10 km - 1 km)
General Navigation
LF: 30 kHz - 300 kHz (10 km - 1 km)
General Navigation
MF: 300 kHz - 3 MHz
(1 km - 100m) Commercial MW Radio
MF: 300 kHz - 3 MHz
(1 km - 100m) Commercial MW Radio
FREQUENCY SPECTRUM: 2/4 FREQUENCY SPECTRUM: 2/4
Saad Haj Bakry
Network Architecture Communications Issues / Signals
SHF: 3 GHz - 30 GHz (10 cm - 1 cm)
Terrestrial Microwave / Satellites
SHF: 3 GHz - 30 GHz (10 cm - 1 cm)
Terrestrial Microwave / Satellites
VHF: 30 MHz - 300 MHz
(10 m - 1 m) Commercial FM Radio / Police /
Airplanes
VHF: 30 MHz - 300 MHz
(10 m - 1 m) Commercial FM Radio / Police /
Airplanes
UHF: 300 MHz - 3 GHz
(1 m - 1 cm) Television / Cellular
UHF: 300 MHz - 3 GHz
(1 m - 1 cm) Television / Cellular
VLF: 30 GHz - 300 GHz (1 cm - 1 mm) Railroad / RADAR
VLF: 30 GHz - 300 GHz (1 cm - 1 mm) Railroad / RADAR
FREQUENCY SPECTRUM: 3/4 FREQUENCY SPECTRUM: 3/4
Saad Haj Bakry
Network Architecture Communications Issues / Signals
VHF BAND: 500 MHz
- 1 GHz
VHF BAND: 500 MHz
- 1 GHz
MICROWAVE BANDS
K BAND: 18 GHz - 26.5
GHz
K BAND: 18 GHz - 26.5
GHz
Ku BAND: 12.4 GHz - 18
GHz
Ku BAND: 12.4 GHz - 18
GHz
X BAND: 8 GHz - 12.4
GHz
X BAND: 8 GHz - 12.4
GHz
C BAND: 4 GHz
- 8 GHz
C BAND: 4 GHz
- 8 GHz
L BAND: 1 GHz -
2 GHz
L BAND: 1 GHz -
2 GHz
Ka BAND: 26.5 GHz - 40
GHz
Ka BAND: 26.5 GHz - 40
GHz
S BAND: 2 GHz -
4GHz
S BAND: 2 GHz -
4GHz
FREQUENCY SPECTRUM: 4/4 FREQUENCY SPECTRUM: 4/4
Saad Haj Bakry
Network Architecture Communications Issues / Signals
LIGHT WAVES: 1 kGHz - 10 MGHz (Infrared - Ultraviolet)
LIGHT WAVES: 1 kGHz - 10 MGHz (Infrared - Ultraviolet)
LIGHT BANDS / SPECIAL RAYS
X RAY: 1 GGHz
X RAY: 1 GGHz
SEEN LIGHT: 428.5 kGHz - 750 kGHz
(Red - Violet)
SEEN LIGHT: 428.5 kGHz - 750 kGHz
(Red - Violet)
GAMA RAY: 100 GGHz
GAMA RAY: 100 GGHz
COSMIC RAY: 100 kGGGHz = 1032
COSMIC RAY: 100 kGGGHz = 1032
DIGITAL SIGNALSDIGITAL SIGNALS
Saad Haj Bakry
Network Architecture Communications Issues / Signals
Noise Separation by ReShaping
Noise Separation by ReShaping
Noise Cannot be Separated from the Signals at
Repeaters and at Destinations
Noise Cannot be Separated from the Signals at
Repeaters and at Destinations
ANALOG:
CONTINUOUS CHANGE
ANALOG:
CONTINUOUS CHANGE
DIGITAL:
DISCRETE CHANGE
DIGITAL:
DISCRETE CHANGE
Digital Processing
Digital Processing
BUT: Wider Band
BUT: Wider Band
INFORMATION SIGNALS: VOICE INFORMATION SIGNALS: VOICE
Saad Haj Bakry
Network Architecture Communications Issues / Signals
FREQUENCY:
0 - 15 kHz
FREQUENCY:
0 - 15 kHz
TELEPHONE VOICE: 300 Hz - 3.4 kHz Spacing: 4 kHz
TELEPHONE VOICE: 300 Hz - 3.4 kHz Spacing: 4 kHz
ANALOGANALOG
SAMPLING: 8 k (sample)
SAMPLING: 8 k (sample)
QUANTIZATION: 256 levels
QUANTIZATION: 256 levels
CODING: Digital Signal 64 kbps
CODING: Digital Signal 64 kbps
PCM: Digital Telephone VoicePCM: Digital Telephone Voice
INFORMATION SIGNALS: PICTURE INFORMATION SIGNALS: PICTURE
Saad Haj Bakry
Network Architecture Communications Issues / Signals
ANALOG TV FREQUENCY
BANDWIDTH: System Dependent
(4 - 10 MHz) Mostly: 6 MHz
ANALOG TV FREQUENCY
BANDWIDTH: System Dependent
(4 - 10 MHz) Mostly: 6 MHz
DIGITAL TV: System Dependent
Usually: 45 Mbps (T3) (Satellite Transponder)
DIGITAL TV: System Dependent
Usually: 45 Mbps (T3) (Satellite Transponder)
PROBLEM: Large Bandwidth
(Compression)
PROBLEM: Large Bandwidth
(Compression)
INFORMATION SIGNALS: DATA INFORMATION SIGNALS: DATA
Saad Haj Bakry
Network Architecture Communications Issues / Signals
BINARY REPRESENTATION: Binary Digit On / Off (bit =0/1) = 2 States
BINARY REPRESENTATION: Binary Digit On / Off (bit =0/1) = 2 States
ASCII CODE:
Character = 7
bits 128 states
ASCII CODE:
Character = 7
bits 128 states
AI5 CODE: ASCII + 1 bit (parity bit / 256 states)
AI5 CODE: ASCII + 1 bit (parity bit / 256 states)
EBCDIC CODE: 8 bits EBCDIC CODE: 8 bits
BAUDOT CODE: 5 bits (32 states) BAUDOT CODE: 5 bits (32 states)
FREQUENCY TRANSLATIONFREQUENCY TRANSLATION
Saad Haj Bakry
Network Architecture Communications Issues / Signals
BASEBAND
SIGNAL: A Signal in its Original Frequency
[0 - fs]
BASEBAND
SIGNAL: A Signal in its Original Frequency
[0 - fs]
OBJECTIVE: Moving a Signal to a
Higher Frequency [(fc)-(fc+fs)]
OBJECTIVE: Moving a Signal to a
Higher Frequency [(fc)-(fc+fs)]
ADVANTAGES:
Channel Assignment & Multiplexing
(Broadband Signals)
Better Radiation at Higher Frequency
ADVANTAGES:
Channel Assignment & Multiplexing
(Broadband Signals)
Better Radiation at Higher Frequency
METHOD: Mixing with a Sinusoidal Signal METHOD: Mixing with a Sinusoidal Signal
BAUD VERSUS bps: 1/2 BAUD VERSUS bps: 1/2
Saad Haj Bakry
Network ArchitectureCommunications Issues / Signals
2 STATES PER SLOT:
1 bit (0/1)
2 STATES PER SLOT:
1 bit (0/1) 4 STATES PER SLOT:
2 bit (00/01/10/11)
4 STATES PER SLOT:
2 bit (00/01/10/11)
8 STATES PER SLOT:
3 bit (000/001/010/011/ 100/101/110/111)
8 STATES PER SLOT:
3 bit (000/001/010/011/ 100/101/110/111)
FORM OF COMPRESSIONFORM OF COMPRESSION
PRACTICAL
EXAMPLE: PSK
BAUD VERSUS bps: 2/2 BAUD VERSUS bps: 2/2
Saad Haj Bakry
Network ArchitectureCommunications Issues / Signals
RATE [bps] = RATE [BAUD] . Ln2 (No. of states)
RATE [bps] = RATE [BAUD] . Ln2 (No. of states)
CASE STUDY: RATE [BAUD] = 9600 2 States Rate (bps) = 9600 bps 4 States Rate (bps) = 19.2 kbps 8 States Rate
(bps) = 28.8 kbps
CASE STUDY: RATE [BAUD] = 9600 2 States Rate (bps) = 9600 bps 4 States Rate (bps) = 19.2 kbps 8 States Rate
(bps) = 28.8 kbps
INTERNAL NOISE INTERNAL NOISE
Saad Haj Bakry
Network ArchitectureCommunications Issues / Signals
JHONSON / TEMPERATURE /
WHITE: All Frequencies
JHONSON / TEMPERATURE /
WHITE: All Frequencies
SHOT NOISE / POWER SUPPLY:
Hum Noise Partition
Noise
SHOT NOISE / POWER SUPPLY:
Hum Noise Partition
Noise
OTHERS: Coupling Transformers Magnetic Fields
OTHERS: Coupling Transformers Magnetic Fields
EXTERNAL NOISE EXTERNAL NOISE
Saad Haj Bakry
Network ArchitectureCommunications Issues / Signals
ATMOSPHERIC:
Thunderstorms (Impulsive)
ATMOSPHERIC:
Thunderstorms (Impulsive)
MAN MADE: Power Lines
Electric Motors Switching
MAN MADE: Power Lines
Electric Motors Switching
EXTRATERRESTRIAL: Sun / Stars
EXTRATERRESTRIAL: Sun / Stars
MULTIPLE
TRANSMISSION
PATH
MULTIPLE
TRANSMISSION
PATH
RATIOS / dB RATIOS / dB
Saad Haj Bakry
Network ArchitectureCommunications Issues / Signals
GAIN / LOSS / SIGNAL-TO-NOISE
GAIN / LOSS / SIGNAL-TO-NOISE
RATIO = POWER (out) / POWER (in)
RATIO = POWER (out) / POWER (in)
RATIO = POWER (signal) / POWER (noise)
RATIO = POWER (signal) / POWER (noise)
RATIO (dB) = 10 log10 (RATIO)RATIO (dB) = 10 log10 (RATIO)
RATIO = 0.1, 1, 10, 100RATIO = 0.1, 1, 10, 100 RATIO (dB) = -10, 0, 10, 20RATIO (dB) = -10, 0, 10, 20
CHANNELSCHANNELS
Saad Haj Bakry
Network Architecture
NATURENATURE
PHYSICALPHYSICAL
USE USE
Communications Issues / Channels
CAPACITY VERSUS BANDWIDTHCAPACITY VERSUS BANDWIDTH
ANALOGANALOG
ISDN / SONET / SDHISDN / SONET / SDH
DIGITAL DIGITAL
PHYSICALPHYSICAL
Saad Haj Bakry
Network Architecture
WIRE:
COPPER Twisted Pair / Cables
OPTICAL FIBER (Low Noise)
PROPAGATION
200,000 km / sec
WIRE:
COPPER Twisted Pair / Cables
OPTICAL FIBER (Low Noise)
PROPAGATION
200,000 km / sec
Communications Issues / Channels
WIRELESS:
TERRESTRIAL Ground Environment
SATELLITE / SPACE Geo-
stationary Altitude: 36,000 km
PROPAGATION
300,000 km / sec
WIRELESS:
TERRESTRIAL Ground Environment
SATELLITE / SPACE Geo-
stationary Altitude: 36,000 km
PROPAGATION
300,000 km / sec
NATURENATURE
Saad Haj Bakry
Network Architecture
SINGLE:
(ONE
WAY)
2 WIRES
(BASEBAND) /
FREQUENCY
(SUB)BAND /
TIME SLOTS
SINGLE:
(ONE
WAY)
2 WIRES
(BASEBAND) /
FREQUENCY
(SUB)BAND /
TIME SLOTS
Communications Issues / Channels
DOUBLE: (TWO
WAY) 4 WIRES
(BASEBAND) /
2 FREQUENCY
(SUB)BANDS /
2 SLOT SETs
DOUBLE: (TWO
WAY) 4 WIRES
(BASEBAND) /
2 FREQUENCY
(SUB)BANDS /
2 SLOT SETs
MULTIPLE: (x) 2 Wire
BASEBAND / (x) Frequency SubBands
BROADBAND /
(x) SLOT SETS
MULTIPLE: (x) 2 Wire
BASEBAND / (x) Frequency SubBands
BROADBAND /
(x) SLOT SETS
CAPACITY VERSUS BANDWIDTHCAPACITY VERSUS BANDWIDTH
Saad Haj Bakry
Network ArchitectureCommunications Issues / Channels
C [bps] = BW [Hz] . ln2 (1+(Ps/Pn))C [bps] = BW [Hz] . ln2 (1+(Ps/Pn))
BW [Hz] = C [bps] / ln2 (1+(Ps/Pn))BW [Hz] = C [bps] / ln2 (1+(Ps/Pn))
SHANNON INFORMATION THEORY
How Can (ln2) be transformed to (log10) to ease computation
ANALOGANALOG
Saad Haj Bakry
Network Architecture
BASE CHANNEL:
Voice Grade 4 kHz
BASE CHANNEL:
Voice Grade 4 kHz
Communications Issues / Channels
GROUP:
12 BASE = 48 kHz
GROUP:
12 BASE = 48 kHz
SUPER GROUP:
5 GROUP=
60 BASE = 240 kHz
SUPER GROUP:
5 GROUP=
60 BASE = 240 kHz
MASTER GROUP:
5 SUPER GROUP
= 25 GROUP
300 BASE = 1.2 MHz
MASTER GROUP:
5 SUPER GROUP
= 25 GROUP
300 BASE = 1.2 MHz
DIGITAL: ITUDIGITAL: ITU
Saad Haj Bakry
Network Architecture
BASE
CHANNEL:
Voice Grade / PCM 64 kbps
BASE
CHANNEL:
Voice Grade / PCM 64 kbps
Communications Issues / Channels
E-1:
30 (+) PCM
2.048 Mbps
E-1:
30 (+) PCM
2.048 Mbps
E-2:
120 (+) PCM 8.448 Mbps
E-2:
120 (+) PCM 8.448 Mbps
E-3:
480 (+) PCM
34.368 Mbps
E-3:
480 (+) PCM
34.368 Mbps
1920 (+) PCM 139.264
Mbps
1920 (+) PCM 139.264
Mbps 7860 (+) PCM / 565.148 Mbps 7860 (+) PCM / 565.148 Mbps
DIGITAL: NADIGITAL: NA
Saad Haj Bakry
Network Architecture
BASE
CHANNEL:
Voice Grade / PCM 64 kbps
BASE
CHANNEL:
Voice Grade / PCM 64 kbps
Communications Issues / Channels
T-1:
24 (+) PCM
1.544 Mbps
T-1:
24 (+) PCM
1.544 Mbps
T-1(C):
48 (+) PCM 3.152
Mbps
T-1(C):
48 (+) PCM 3.152
MbpsT-2:
96 (+) PCM 6.312 Mbps
T-2:
96 (+) PCM 6.312 Mbps
T-4: 4032 (+) PCM / 274.176 MbpsT-4: 4032 (+) PCM / 274.176 Mbps
T-3:
672 (+) PCM 44.736 Mbps
T-3:
672 (+) PCM 44.736 Mbps
ISDNISDN
Saad Haj Bakry
Network Architecture
BASE
CHANNEL:
B = 64 kbps D = 16 kbps (Basic Rate: Individual)
D = 64 kbps (Primary Rate: Organization)
BASE
CHANNEL:
B = 64 kbps D = 16 kbps (Basic Rate: Individual)
D = 64 kbps (Primary Rate: Organization)
Communications Issues / Channels
BASIC RATE:
2B + D 144 kbps
BASIC RATE:
2B + D 144 kbps
PRIMARY RATE :
23B + D = (24B) 1.544 Mbps
PRIMARY RATE :
23B + D = (24B) 1.544 Mbps
H0: 6B
384 kbps
H0: 6B
384 kbps
H11: 24B
1.536 Mbps
H11: 24B
1.536 Mbps
H12: 30B
1.92 Mbps
H12: 30B
1.92 Mbps
H4: 9720B
622.08 Mbps
H4: 9720B
622.08 Mbps
SONET / SDHSONET / SDH
Saad Haj Bakry
Network Architecture
OC-1:
51.840 Mbps
OC-1:
51.840 Mbps
Communications Issues / Channels
OC-3 / STM-1:
155.250 Mbps
OC-3 / STM-1:
155.250 Mbps
OC-48:
2.488 GbpsOC-48:
2.488 GbpsOC-12 / STM-4:
622.08 Mbps
OC-12 / STM-4:
622.08 Mbps
USEUSE
Saad Haj Bakry
Network Architecture
DIAL UP: Normal Use of
Telephone Lines (Individuals)
DIAL UP: Normal Use of
Telephone Lines (Individuals)
Communications Issues / Channels
LEASE: Dedicated Hot Link of Any Capacity (Organizations)
LEASE: Dedicated Hot Link of Any Capacity (Organizations)
SHARE: Such as in Virtual Private Networks
SHARE: Such as in Virtual Private Networks
FLOWFLOW
Saad Haj Bakry
Network Architecture
PARALLEL / SERIALPARALLEL / SERIAL
Communications Issues Flow
DIRECTIONDIRECTION
ASYNCHRONOUS ASYNCHRONOUS
SYNCHRONOUS SYNCHRONOUS
PARALLEL / SERIALPARALLEL / SERIAL
Saad Haj Bakry
Network ArchitectureCommunications Issues Flow
0011 0011 00 001111
SERIAL:
ONE CHANNELPARALLEL:
MULTIPLE CHANNELS
DIRECTIONDIRECTION
Saad Haj Bakry
Network Architecture
SIMPLEX: One Direction
TRANSMITTER (T) Single RECEIVER (R)
SIMPLEX: One Direction
TRANSMITTER (T) Single RECEIVER (R)
Communications Issues / Flow
HALF DUPLEX: One at a Time
(T) / (R) Single (T) / (R)
HALF DUPLEX: One at a Time
(T) / (R) Single (T) / (R)
FULL DUPLEX: Two Simultaneously
(T) / (R) Double (T) / (R)
FULL DUPLEX: Two Simultaneously
(T) / (R) Double (T) / (R)
ASYNCHRONOUSASYNCHRONOUS
Saad Haj Bakry
Network ArchitectureCommunications Issues Flow
0011 0011 00 001111SS
START STOPDATA: 1 Character
INTERMITTENT FLOW
High Control Overheads: 20 % High Control Overheads: 20 %
SYNCHRONOUSSYNCHRONOUS
Saad Haj Bakry
Network ArchitectureCommunications Issues Flow
SYNC. SYNC.DATA: 1 Block
CONTINUOUS FLOW
Lower Control OverheadsLower Control Overheads
SS SS
MODULATIONMODULATION
Saad Haj Bakry
Network Architecture
MODEMSMODEMS
PRINCIPLESPRINCIPLES
Communications Issues / Modulation
ANALOGANALOG PULSEPULSE DIGITAL DIGITAL
PRINCIPLESPRINCIPLES
Saad Haj Bakry
Network Architecture
OBJECTIVE: Transferring Information Signals to a New Form
Suitable for the Target
Communication System
OBJECTIVE: Transferring Information Signals to a New Form
Suitable for the Target
Communication System
Communications Issues / Modulation
CONCEPT: Changing Some
Features of a “CARRIER” Signal (New Form)
According to the Information
Signal to be “CARRIED”
CONCEPT: Changing Some
Features of a “CARRIER” Signal (New Form)
According to the Information
Signal to be “CARRIED”
FEATURES:
• AMPLITUDE
• PHASE
• FREQUENCY
• (CODING)
FEATURES:
• AMPLITUDE
• PHASE
• FREQUENCY
• (CODING)
ANALOGANALOG
Saad Haj Bakry
Network Architecture
INFORMATION
SIGNALS:
ANALOG
CARRIER
SIGNAL:
ANALOG
(Sinusoidal)
INFORMATION
SIGNALS:
ANALOG
CARRIER
SIGNAL:
ANALOG
(Sinusoidal)
Communications Issues / Modulation
METHODS:
AMPLITUDE MODULATION (AM)
Radio / TV Picture / Telephone
PHASE MODULATION (PM)
FREQUENCY MODULATION (FM)
Radio / TV Voice / Mobile
METHODS:
AMPLITUDE MODULATION (AM)
Radio / TV Picture / Telephone
PHASE MODULATION (PM)
FREQUENCY MODULATION (FM)
Radio / TV Voice / Mobile
PULSEPULSE
Saad Haj Bakry
Network Architecture
INFORMATION
SIGNALS:
ANALOG
CARRIER
SIGNAL:
PULSE
(Digital)
INFORMATION
SIGNALS:
ANALOG
CARRIER
SIGNAL:
PULSE
(Digital)
Communications Issues / Modulation
METHODS:
PULSE AM (PAM)
Sampling Analog Information
Signals
PULSE CODE MOD. (PCM)
Transforming Analog Information Signals to Digital
METHODS:
PULSE AM (PAM)
Sampling Analog Information
Signals
PULSE CODE MOD. (PCM)
Transforming Analog Information Signals to Digital
DIGITALDIGITAL
Saad Haj Bakry
Network Architecture
INFORMATION
SIGNALS:
DIGITAL
CARRIER
SIGNAL:
ANALOG
(Sinusoidal)
INFORMATION
SIGNALS:
DIGITAL
CARRIER
SIGNAL:
ANALOG
(Sinusoidal)
Communications Issues / Modulation
METHODS:
AMPLITUDE SHIFT KEYING (ASK)
PHASE SHIFT KEYING (PSK)
FREQUENCY SHIFT KEYING (FSK)
Transforming Digital Information Signals to Analog
(Example: MODEMS)
METHODS:
AMPLITUDE SHIFT KEYING (ASK)
PHASE SHIFT KEYING (PSK)
FREQUENCY SHIFT KEYING (FSK)
Transforming Digital Information Signals to Analog
(Example: MODEMS)
MODEM: EXAMPLE MODEM: EXAMPLE
Saad Haj Bakry
Network ArchitectureCommunications Issues / Modulation
C (kbps)MODEM
Digital Analog
BW = 4 kHz
Capacity “C” Depends on the Channel “BW” & MODEM
Capaity “C” Can be Increased by Multilevel (BAUD) Signals / Compression (e.g. PSK)
FSK SEND CHANNEL: f(0) = 1180 Hz (0 bit)
f(1) = 980 Hz (1 bit)
FSK SEND CHANNEL: f(0) = 1180 Hz (0 bit)
f(1) = 980 Hz (1 bit)
FSK RECEIVE CHANNEL: f(0) = 1850 Hz (0 bit)
f(1) = 1650 Hz (1 bit)
FSK RECEIVE CHANNEL: f(0) = 1850 Hz (0 bit)
f(1) = 1650 Hz (1 bit)
MODEM: CONNECTION MODEM: CONNECTION
Saad Haj Bakry
Network ArchitectureCommunications Issues / Modulation
PC-MODEM (RS-232) Serial Interface (25 pins)
DATA: 2 / 3 (14 /16)DATA: 2 / 3 (14 /16) CONTROL: 4 / 5 / 6 / 8 / 20 / 21 / 22 / 23
(12 /13 /19)
CONTROL: 4 / 5 / 6 / 8 / 20 / 21 / 22 / 23
(12 /13 /19)TIMING: 24 / 15 / 17TIMING: 24 / 15 / 17
GROUND: 1 / 7 (Return)GROUND: 1 / 7 (Return)
RESERVED: (9 / 10)RESERVED: (9 / 10)
UNASSIGNED: (11 / 18 /
25)
UNASSIGNED: (11 / 18 /
25)
SUGGESTED WORK: ANALYSISSUGGESTED WORK: ANALYSIS
Saad Haj Bakry
Network ArchitectureCommunications Issues / Work
BAUD / LEVELS / bpsBAUD / LEVELS / bps
RATIO (dB) Versus RATIORATIO (dB) Versus RATIO
C / BW / (PS / PN)C / BW / (PS / PN)
GENERIC / SPECIFIC INVESTIGATIONSGENERIC / SPECIFIC INVESTIGATIONS
SUGGESTED WORK: PRACTICALSUGGESTED WORK: PRACTICAL
Saad Haj Bakry
Network ArchitectureCommunications Issues / Work
MODEMSMODEMS
PRACTICAL SYSTEMS & STANDARDSPRACTICAL SYSTEMS & STANDARDS
FLOWSFLOWS
CHANNELSCHANNELS
