An introduction to communication system as a part of one complete course about using communication modules along with PIC-Micro-controller Thanks.

1. Communication PIC-Microcontroller Lab
Course by JAOM Center, Feb. 2013
Introduction to
Communication Systems
Instructor:
Mohsen Sarakbi

2. Definitions of Communication
 The word itself is derived from the Latin verb communicare,
which means "to share" or "to make common".
 Communication is the transfer of information from one place
to another.
 Simply: To connect source & destination.

3. Definitions of Communication
 For a best communication, connection should be:
o As efficiently as possible
o With as much fidelity/reliability as possible
o As securely as possible

4. Communication System
 Communication Systems became essential, and gained an
important position in our lives, we can touch its effect in
every aspects of life.
 Examples: Networks, internet, satellites, mobile phone
system, GPS, Radar ….. etc).

5. Parts of Communication System
 Communication systems consist of five parts:
Source, Transmitter, Channel, Receiver, and Destination.
Shannons Model of Communication

6. Parts of Communication System
 Source (input signal):
o The source originates a message, such as (human voice, the
television picture, data).
o If the data is non-electrical (analogue) it must be converted by an
input transducer (microphone, camera…) into an electrical
waveform (baseband modulation) referred to as the baseband
signal or message signal.

7. Parts of Communication System
 Transmitter (TX):
o The transmitter modifies the base-band signal for efficient
transmission.
o Characteristics: Modulation, amplification, transmission frequency
(TX), transmission power, coding...
o MW modem,WiFi Card, Bluetooth Card, RF transmitter..

8. Parts of Communication System
 Channel:
o The Channel is a medium, such as wire, coaxial cable, a
waveguide, an optical fiber or a radio link (air interface), through
which the transmitter output is sent.
o Channel characteristics, ability for transmission, noise,
interference, power needed, fading, multipath...

9. Parts of Communication System
 Receiver (RX):
o The receiver reprocesses the signal received from the channel by
undoing the signal modifications made at the transmitter and the
channel.
o Characteristics: Demodulation, receiver frequency (RX),
receiving power (threshold), decoding...
o MW modem,WiFi Card, Bluetooth Card, RF receiver..

10. Parts of Communication System
 Destination (output signal):
The destination is the unit to which the message is communicated.
The receiver output is fed to the output transducer (Monitor,
Speaker…), which converts the electrical signal to its original form.

11. Parts of Communication System
 Transmitted/Received Signal
o Modulated signal or encapsulated signal.
This signal is modified by the transmitter/receiver
o Examples:
Ethernet frame:
MW frame:

12. Parts of Communication System
 Transceiver
Is a One devices (transmitter/receiver) that do the role of
the two devices.
o Bidirectional communication.
o Higher Cost!

13. Modes of Channel Operation
 Simplex:
o Simplex is one direction of communication, it requires only one line of communication.
o Simplex channels are not often used in communication systems because it is not possible to send back
error or control signals to the transmit end.
o A good example would be TV or Radio
 Half-Duplex:
o Two directions of communication (can send & receive) but only one direction is allowed through at a time.
o Only one end transmits at a time, the other end receives. In addition, it is possible to send feedbacks.
o An advantage is that the single lane is cheaper then the double lane (less connecters).
o Example of half-duplex is talk-back radio, and CB Radio (Citizens Band).
 Full Duplex:
o Two ways of communication with data can travel in both directions simultaneously. This is the most
common channel operation in communication systems and networking.
o It can perform feedbacks.
o The most expensive (special devices and more connecters, as in case of fiber optics SFPs)
o Example, is mobile phone line.

14. Modes of Channel Operation

15. Real Life Example, Telecommunication

16. Real Life Example, Satellite System

18. Our Course
Data Transmission
RF, Bluetooth,
XBEE, Wi-Fi,
GSM

19. Transmission
Technology
RF
Bluetooth
XBEE
Wi-Fi
GSM
o All transmission methods are using TX/RX modules.
o GSM, is not P-t-P directly connected channel (over existing mobile network)

20. Transmission

21. Transmission
What is Transmission?
Where is the Transmission Network exist (Topology)?
What to Transmit (Media)?

22. Transmission
What is Transmission?
Transporting
Traffic: Voice, Data, Signaling ...
Connecting

23. Transmission
Where is the Transmission
Network exist?
Between Network Elements
Mobile Network

24. Transmission
How to Transmit?
Radio Link (Microwave)
+ Rapid installation
+ No "right of way" required
-limited capacity Up to 1,2 GB/s IP capacity
- Sensitive to ambient disturbance
(rain and multipath fading)
- Radio license fees
Fiber Optics
+ High transmission capacity
+ High transmission quality
+ Resistant to ambient disturbance
+Maximum distances 100 up 150 km
between repeaters
-Long implementation time

25. Transmission
How to Transmit?
Direct Cables (Coax)
+Reliable
-Low medium distance
(decrease with capacity)
Leased Lines
High Cost!

26. Electromagnetic Spectrum
• Transmission should be done using EM waves

27. Electromagnetic Spectrum

28. Signal Bandwidth
The bandwidth of a composite signal is the difference between the highest and the
lowest frequencies contained in that signal.

29. History of communication systems
Advanced electrical and electronic signals::
1893: Wireless telegraphy
1896: Radio
1927: Television
1927: First commercial radio-telephone service, U.K.–U.S.
1936: World's first public videophone network
1946: Limited capacity Mobile Telephone Service for automobiles
1962: Commercial telecommunications satellite
1964: Fiber optical telecommunications
1969: Computer networking
1973: First modern-era mobile (cellular) phone
1981: First mobile (cellular) phone network
1982: SMTP email
1983: Internet
1998: Mobile satellite hand-held phones
2003: Skype Internet telephony