The document discusses key elements of data communication systems including learning outcomes, system elements, data elements, communication devices, electronic communication methods, transmission media, and common transmission flaws. Specifically, it identifies main elements as data, communication devices, transmission methods, and media. It describes different wired and wireless devices, transmission types like analog and digital, multiplexing, and flaws such as noise, attenuation, latency, and interference that can affect signals.
Scaling API-first – The story of a global engineering organization
Topic 1.2 principle of communication in networking
1.
2. Learning Outcomes
• Identify main elements in data communication
systems
• Identify the communication devices
• Explain the basic data transmission concepts
• Describe the common transmission flaws effecting
data signals
• Explain the rule of communication
• Explain how signals transmitted from a host to a
destination in a network
4. Data Elements
• Message - information to be communicated
• Sender - device that sends the message
• Receiver - device that receives the message
• Medium - physical path from sender to
receiver
• Protocol - set of rules that govern data
communication
6. Communication Devices
A hardware component that enables a
computer to send and receive data,
instructions and information and from one or
more computers.
Type of communication devices:
Wired (Data Terminal Equipment
(DTE))
Wireless (3G,GPRS, Laptop, Mobile
Phones)
7. Wired Communication
• Wired communication is transmission of
data over a wire-based communication
technology.
• One of common wired-based communication
is an Ethernet.
• DTE ( data terminal equipment) and DCE
(data circuit-terminating equipment / data
communications equipment).
8. Wireless Communication
• Wireless communication is the transfer of information
between two or more points that are not connected by
an electrical conductor
10. Transmission Media
Guided Media
Twisted-Pair Cable – Unshielded Twisted-Pair (UTP) and
Shielded Twisted-Pair (STP)
Coaxial Cable
Fiber Optic Cable
Unguided Media: Wireless
Transport electromagnetic waves without using a physical
conductor
11. Twisted Cable
• Unshielded Twisted Pair (UTP)
• Shielded Twisted Pair (STP)
STP cable consists of twisted wire
pairs that are individually insulated
and surrounded by shielding
made of metallic substance
UTP cable consists of one or more
insulated wire pairs encased in a
plastic sheath
12. Comparing STP and UTP
Throughput - Both can transmit up to 100 Mbps
Cost - Typically, STP is more expensive
Connector - Both use RJ-45 connectors
Noise immunity - STP is more noise-resistant
Size and scalability - Maximum segment length for
both is 100 meters
Throughput refers to the
volume of data that can flow
through a network
13. RJ-45
RJ45 is a standard type of connector for
network cables
Crossover cable must be used between 2 devices from the same
level like (PC-PC, Router-Router, Switch-Hub, PC-Router)
Straight through cable used between two different levels like
(PC-Switch, Router-Switch) – T-568A / T-568B
14. Coaxial Cable
• Coaxial cables are a type of
cable that is used by cable TV
and that is common for data
communications.
• There are two types of
coaxial cable:
Thinnet (thin)
Thicknet (thickness)
• The coaxial cable using
connectors - BNC (British
Naval Connector)
15. Fiber Optic
Contains one or several glass fibers at its core
Surrounding the fibers is a layer of glass called
cladding
16. Fiber Optic (cont…)
Single-mode fiber
Carries light pulses along single path
Multimode fiber
Many pulses of light generated by LED travel at
different angles
17. Unguided Media: Wireless
Infrared transmission
Infrared networks use infrared light signals to
transmit data through space
Direct infrared transmission depends on
transmitter and receiver remaining within line of
sight
In indirect infrared transmission, signals can
bounce off of walls, ceilings, and any other
objects in their path
18. Unguided Media: Wireless
RF transmission
Radio frequency (RF) transmission relies on
signals broadcast over specific frequencies
Two most common RF technologies:
Narrowband
Spread
spectrum
19. Data Transmission Concept
Analog and digital
signaling
Data modulation
Simple, half-duplex
and full-duplex
Multiplexing
Point-to-point
transmission
Broadcast
transmission
Bluetooth, 3G
Throughput
Bandwidth
EXERCISE
20. Transmission Flaws
FLAW is any defect that can affect the
quality of data signal send in networking.
Most common flaws is
• Noise
• Attenuation
• Latency
• Radio frequency interference (RFI)
• Electromagnetic interference (EMI)
21. Transmission Flaws
Noise
Occurred when devices act as a sending antenna and
the transmission medium act as the receiving antenna.
Analog Signal Digital Signal
22. Transmission Flaws
Attenuation
Loss of signal strength as transmission travels away
from source (for long network cable)
Analog signals pass through an amplifier, which
increases not only voltage of a signal but also noise
accumulated
An analog signal
distorted by
noise, and then
amplified
Amplifier - device for increasing the power
of a signal by use of an external energy
source
23. Transmission Flaws
Latency
Latency is the delay between requesting data and the
receipt of a response, or in the case of one-way
communication, between the actual moment of a signal's
broadcast and the time it is received at its destination
24. Transmission Flaws
Radio frequency interference (RFI)
Interference that may be generated by motors, power
lines, televisions, copiers, fluorescent lights, or broadcast
signals from radio or TV towers
Electromagnetic interference (EMI)
Interference that may be caused by motors, power lines,
television, copiers, fluorescent lights, or other sources of
electrical activity
25. Transmission Flaws
Regeneration
Process of retransmitting a digital signal
Repeater
Device used to regenerate a signal
A digital signal distorted by noise, and then
repeated
26. I don’t stop when I’m tired.
I only stop when I’m done…