http://asecuritysite.com/csn08704

1. CSN08704
Data, Audio, Video and Images
http://asecuritysite.com/comms
Telecommunications
Prof Bill Buchanan
Pre-Introduction

2. A Few Principles
• We have a
transmitter, a
receiver and
transmission media.
• Information flows
from two entities
over a channel.
• We can have
broadcast or point-
to-point.
Channel
Information flow
(data, images, sound, audio, video,
etc)
Channel
Transmitter Receiver
Transmission
media
Point to point
Broadcast
Channel
Latency (time to propagate)
Bandwidth (capacity of channel)
Security (ability to secure)

3. Intercommunications
• Differing inputs signals.
• Differing transmission
media and transmission
rates.
• Different addressing
methods: eg IP address
and Telephone Number.
• Different Quality of
Service (QoS)
requirements ... fast or
reliable?
Analogue Digital
Speech
Audio
Data
Video
GSM/3G
Network
Wi-fi
Network
IP Network
POT (Plain Old
Telephone)
Network
Analogue-
to-Digital
Conversion
(ADC)
Digital-to-
Analogue
Conversion
(DAC)
Optical
fibre
Radio links
Copper
cables
Satellite
links

4. Every increasing demand ...
• Ever increasing
requirement for
network capacity.
• Every increasing
reliance for “always-
on” and “always
available” network
connection.
• Number of devices
connecting increases
by the day.
12 TB of Tweets sent
every day
90% of all data in the
Cloud produced in the last
two years
2,500,000,000,000,000
bytes of data produced
ever day – 2.5 Quintillion
Bytes – 1 billion hard
disks
It’s all going digital:
 Data.
 Voice.
 Video.
 Sensors
All going digital:
Banking.
Oil and Gas.
e-Commerce.
Transport.
Every increasing demand
for network capacity
Every increasing requirement for
data capture, storage and analysis
By 2020, 20 million
Internet of Things devices
connecting to the Internet
Move towards an “always
on” and “always
available” network
connection
Telecoms industry worth
$4.7 trillion (3% of gross
world product)

5. Communication Media
• Many different types
of media ... radio ...
electrical signals ...
light pulses.
Point-to-point
radio links
Coaxial cable
Fibre optics
Satellite
communications
Radio
transmission
Transmission
media
Twisted-pair
copper cable
Local Wi-fi
Bluetooth

6. Differing transmission rate
• The speed of a
connection
typically measured
in the amount of
bits that can be
sent per second
(bps).
• Media differs in its
capacity.
RS-232:
9600 bps
Ethernet:
Fast Ethernet: 100Mbps
Gigabit Ethernet: 1Gbps
10GE: 10Gbps
Satellite comms:
200 Mbps
Point-to-point:
200 Mbps
Wi-fi (IEEE 802.11)
54 Mbps
Fiber optics:
40 Gbps

7. Network convergence
• Fusion of many
different
information sources
into a digital
communication
network.
Speech
Audio
Video
Digital
communication
network
Phone network
Computer network
Control systems network
Speech, audio and video

8. Network convergence ... differing
requirements
• Communication
channel has
many different
aspects. Inc
support for
legacy systems.
Latency
- Minimum delay.
- Maximum delay
Security
- Physical
access.
- Wire taps.
- Route taken.
Bandwidth
- Capacity.
- Guaranteed.
Cost
- Cost per data.
- Cost per day.
Robustness
- Failover.
- Outages.
Access
Methods
- Connections to
network.
- Cost of access.

9. Network convergence ... differing
requirements
• Different types of
traffic have different
needs (Quality of
Service – Latency
(the delay in the
transmission
channel) v Error
sensitivity.
Computer Data
Non-critical and
robust data
transmission (Fax)
Real-time Control
Systems
Voice, Audio and
Video
Low Latency
Error
sensitivity
High
Low
High Latency

10. Ever Increasing Demand
• Increasing hosts
connecting.
• Increasing services ...
games ... TV ... e-
Commerce ... Cloud ...
7.2 billion mobile phones
connecting to communications
infastructure
On-line games
Digital TV
Communication
Service
Providers
e-Commerce
Cloud providers
Service Providers
By 2020, 20 billion devices
to connect to the Internet
Communication
Device
Providers
Host IP addresses have
been exhausted

11. CSN08704
Data, Audio, Video and Images
http://asecuritysite.com/comms
Telecommunications
Prof Bill Buchanan
Pre-Introduction