Communication and Networks Assignment
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0_Lesson2HistoryoftheInternet.pptxCommunications and Networks
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Diploma in Information Technology
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Lesson 2: History of the Internet
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Lesson 2 Learning Outcomes
Describe the motivation for resource sharing
Describe how the Internet has evolved to the present state
Describe the evolution in audio that has occurred in the Internet
Describe the impact of the Internet on cable television industry
Describe the significance of wireless Internet access
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Lesson 2 Outline
Brief History
Changes on the Internet
Impact on Cable TV Industry
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Early Computer Networks
Early computers networks when computers were large and very expensive, and the main motivation was resource sharing
To connect multiple users
Each with a screen & keyboard (terminals) to a large centralized computer
Allows sharing of peripheral devices
Permitted sharing of expensive, centralized resources
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Birth of the Internet
In 1960s, Department of Defense for Advanced Research Projects Agency (DARPA or ARPA) wanted to find ways to share resources
Researchers needed powerful computers, but were very expensive
ARPA budget was insufficient
ARPA planned to interconnect all computers with a network!
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ARPANET
ARPA devise a software that would allow a researcher to use whichever computer was best suited to perform a given task
ARPA did the following to achieve the visionary work:
gathered some of the best minds
focused them on computer network research
hired contractors to turn the designs into a working system: ARPANET
Research turned out to be revolutionary
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Growth of the Internet
In less than 30 years…
the Internet has grown from ARPANET
Connecting a handful of sites to a global communication system
The rate of growth has been phenomenal!
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Exponential Growth
Source: Douglas, C (2016) Computer Networks and Internets
x-axis: the year
y-axis: number of computers attached to the Internet, in millions
Exponential growth between 1980s-2000s
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Early Internet Timeline
Source: Douglas, C (2016) Computer Networks and Internets
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Lesson 2 Outline
Brief History
Changes on the Internet
Overview
Technological Changes
Application Changes
Impact on Cable TV Industry
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Changes in the Internet
The Internet changed in two ways:
Communication speeds increased dramatically
New applications arose that appealed to many parts of the society
No longer dominated by scientists and engineers, scientific applications, or access to computational resources
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Technological Changes
Internet was born out of resource sharing
More for communication now
Two technological changes that shifted the Internet
Higher communication speeds
Enable large data to be transferred quickly
Affordable personal computers
Powerful computational power and graphical display eliminates needs for resource sharing
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Text to Multimedia
Data being sent across the Internet has changed
Multimedia: combination of text, audio, graphics and video
Originally only text but change to images, videos and audio
Source: Douglas, C (2016) Computer Networks and Internets
Email, files
1970s
Mixed Media
1980s
Multimedia
1990s
On-demand
Real-time
2000s
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Audio Content on the Internet
Much of the content available is now multimedia
Quality of media also improved due to higher bandwidth
High resolution video and high-fidelity audio
Source: Douglas, C (2016) Computer Networks and Internets
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Static to Dynamic
The Internet has transitioned from transfer of static textual documents
Now the Internet can transfer dynamic high-quality multimedia
Offline vs real-time requirements
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Changes in Technologies
New technologies continue to emerge
Most significant transitions are the traditional communication systems
Voice and television moved from analog to digital
Support for mobile communication
Although the Internet applications changes, the underlying technologies remain the same
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Analogue vs Digital
Analogue: analogue signals
Sounds waves, which vary continuously over time are analogue data
Digital: digital signals (bits)
Each bit can be represented by one of a number of discrete energy values
Superior performance
Computers produce digital data that is in binary form, that is, it is represented as a series of 1s and 0s
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Practice 2.1
Describe the two motivations of resource sharing
What are the two ways in which the Internet has changed since 1960s?
B
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Digital and Analogue Signals
Source: https://www.youtube.com/watch?v=RQc_frX50BA
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Lesson 2 Outline
Brief History
Changes on the Internet
Overview
Technological Changes
Application Changes
Impact on Cable TV Industry
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Technology Changes
The Internet has enabled some technology changes
Learning points
Traditional way of doing certain task
Modern way of doing certain task
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Telephone System
Before: analog transmission of audio
Use the analog telephone circuits to communicate
Known as the Public Switched Telephone Network (PSTN)
After: digital transmission of audio
Uses the Internet infrastructure to communicate
Voice over Internet Protocol (VoIP)
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How Telephone Works
Source: https://www.youtube.com/watch?v=hDCSMN-h8RU
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Television
Before: wired analog channel
Can also make use of satellite dishes to receive TV broadcasts
After: wired/wireless digital
Can be received wireless
Digital transmission
Uses Internet Protocol (IP) for transmission
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Cellular
Before: analog wireless cellular services
Satellite dishes on Earth
No connection to the Internet
After: digital cellular services
3G onwards
High speed mobile data
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Internet Access
Before: wired, dial-up modem
Make use of telephone circuits
Cannot use telephone while connected
After: wireless, broadband, fibre optic
Wi-Fi
Separate/shared channel from telephone
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Significance of Wi-Fi
Before: mobile devices has to have mobile data connectivity
Additional hardware needed for Internet Access
Incurs mobile data charges
After: any device near a Wi-Fi broadcast can access the Internet
Allows for less powerful electronic devices to connect to the Internet
Save on mobile data charges
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Data Access
Before: centralised
Single server, multiple users
Bottleneck performance
After: distributed, peer-to-peer (P2P)
User can act as servers (Torrent)
Can be used as backups
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Content Delivery
Before: requires download to view
Sometimes slow download
Impact work efficiency
After: streaming
Can view content on browser
Video streaming
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Applications
Before: standalone, download and install
Updates requires additional download
Manual updates
After: cloud, auto-updates
Low cost computers, good productivity
No need to install applications, save space
Auto updates
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Technology on the Internet
| Area | Before | After | Technology |
| Telephone System | Analog voice | Voice over IP | VoIP |
| Television | Analog delivery | Digital delivery | Internet Protocol (IP) |
| Cellular | Analog cellular services | Digital cellular services | 3G |
| Internet Access | Wired, Dial-up | Wireless | Wi-Fi |
| Data Access | Centralised | Distributed | P2P |
| Content Delivery | Download | Streaming | Video streaming |
| Applications | Standalone | Cloud | Cloud services |
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Practice 2.2
How has the Internet changed the telephone system?
What are the 2 benefits of wireless Internet access?
B
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Lesson 2 Outline
Brief History
Changes on the Internet
Overview
Technological Changes
Application Changes
Impact on Cable TV Industry
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Application Trends
Technological advances has lead to many new Internet applications
Learning points
Definition
Benefits
Examples
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Teleconferencing Systems
Teleconferencing system: combination of software and hardware to allow virtual meetings
Made possible by technological changes
Benefits
Reduces travel expenses/costs
Communicate anywhere
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Navigation System
Navigation system: combination of software and hardware that provides users with map functions
Enabled by cloud technologies
Benefits
Can navigate to new locations
No need for standalone GPS system
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Social Media
Social Media: community or platform that facilitates sharing and creation of multimedia
Enabled by availability and accessibility of the Internet
Benefits
Creates and maintains social connections
Meet new people
Entertainment purposes
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Forums
Forums: platform that engage participants in some form of discussions
Contributes to community development
Benefits
Get help easily
Mostly free to use
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Wikis
Wikis: platforms facilitates and maintain knowledge creation and sharing
Enabled by growing capacity and reduction in price of storage devices available on the Internet
Benefits
Public access knowledgebase
Contains plenty of content
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Blogs
Blogs: customisable website that allows individual to share and create contents
Can be used to review products or act as a personal diary
Benefits
Can be designed to suit individual needs
Often free to create
Easily accessible to most people
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Email: electronic mail system that facilitates sending of multimedia messages
Important form of communication and can be used in courts as evidence
Benefits
Supported on most devices
Almost instant delivery
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E-commerce
E-commerce: online retail platform that facilities sales transactions
Enabled by online payment services
Benefits
Shop anywhere
Shop anytime
Cost effective transactions
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Remote Working
Remote Working: ability to work and remain productive anywhere
Enabled by remote access services
Benefits
Can access to complex software running on powerful computers
Allows mobile devices to be productive
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Applications on the Internet
| Area | Uses | Example |
| Teleconferencing | Business-to-business communication | Skype, Zoom |
| Navigation Systems | Military, shipping industry, consumers | Google Map |
| Social Media | Consumers, volunteer organisations, businesses | Instagram, Facebook |
| Forums | Discussions | Reddit, Stack Overflow |
| Wikis | Knowledge sharing | Wikipedia |
| Blogs | Branding, diary | Wordpress |
| Textual communication | Gmail, Hotmail | |
| E-commerce | Consumers, businesses | Amazon, Lazada, Shopee |
| Remote Working | Remote access | TeamViewer, Google Docs |
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Practice 2.3
Define E-commerce and how has the Internet help to enable E-commerce?
What are the two benefits of remote working?
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Lesson 2 Outline
Brief History
Changes on the Internet
Impact on Cable TV Industry
46
Cable TV Companies
Often laid networks across metropolitan areas
Primarily to carry signals from cable TV head-end to individual homes
Most have been designed as cascaded star networks with head-end as central hub
Can usually support about 400,000 subscribers from a Regional Cable Head (RCH)
Cable TV Company
RCH
RCH
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Cable TV Network
Original cable TV networks used copper coaxial cables
From RCH via a series of splitters and amplifiers to homes
Modern networks have been re-engineered
To use optical fibre cables
But cost of running it to each home is prohibitive
As such, optical network is converted back to copper at Fibre Nodes in street cabinets
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Cable TV Network Architecture
RCH feeds a number of Distribution Hubs
Can support about 40,000 subscribers via switches and Fibre Nodes
Fibre Node will split TV signals and transmit over coaxial cable
Can provide service to about 1,000 homes using a tree topology
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Hybrid Network
Cable TV networks are known as Hybrid Fibre-Coaxial networks
Can be adapted to provide a backwards channel to support interactive services
Most cable TV companies have adapted their networks to support broadband services using cable modems
Coaxial cables carrying TV signals also carry downstream and upstream data channel
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Cable TV as Service Providers
Cable TV companies also supports voice services
But usually via a separate cable
Carried over separate channels to RCH where these voice channels are connected to the telephone network circuits
Cable TV companies offer similar products to enterprises as network operators
Like private circuits, LAN extension and IP VPNs
Access charges for use of the cable TV network are subsumed within prices charged for the WAN services
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Practice 2.4
What type of cables did cable TV provider used to provide services to individual homes?
Why is cable TV network sometimes known as hybrid networks?
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Reading
Douglas, C. (2016). Computer Networks and Internets, Global Edition (6th ed.). Pearson Education. ISBN: 978-1292061177 Chapter 2
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End of Lesson
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