Embed Size (px)
Citation preview
CSN08704
Data, Audio, Video and Imageshttp://asecuritysite.com/comms
Telecommunications
Prof Bill Buchanan
Pre-Introduction
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
Transmissionmedia
Point to point
Broadcast
Channel
Latency (time to propagate)Bandwidth (capacity of channel)
Security (ability to secure)
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/3GNetwork
Wi-fiNetwork
IP Network
POT (Plain Old Telephone)
Network
Analogue-to-Digital
Conversion (ADC)
Digital-to-Analogue
Conversion (DAC)
Opticalfibre
Radio links
Coppercables
Satellitelinks
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)
Communication Media• Many different types
of media ... radio ... electrical signals ... light pulses.
Point-to-pointradio links
Coaxial cable
Fibre optics
Satellite communications
Radio transmission
Transmission media
Twisted-paircopper cable
Local Wi-fi
Bluetooth
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: 100MbpsGigabit Ethernet: 1Gbps10GE: 10Gbps
Satellite comms:200 Mbps
Point-to-point:200 Mbps
Wi-fi (IEEE 802.11)54 Mbps
Fiber optics:40 Gbps
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
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.
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
Ever Increasing Demand• Increasing hosts
connecting.• Increasing services ...
games ... TV ... e-Commerce ... Cloud ...
7.2 billion mobile phones connecting to communications
infastructureOn-line games
Digital TVCommunication 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
CSN08704
Data, Audio, Video and Imageshttp://asecuritysite.com/comms
Telecommunications
Prof Bill Buchanan
Pre-Introduction
