Communication and Networks: A historical perspective

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Communication and Networks A historical
perspective

• EPL 324
• Andreas Pitsillides

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Communicating Humans
From human presence on earth Some selected
examples

• Sign language? ---first (?) intelligent form of
  communication?
• Allows communication, BUT
• Limited by distance (100s of meters), need
  visual contact coded and limited by lack of
  richness of language Quality of Communication
  poor.
• Speech
• Richness of language, more natural, but limited
  by distance (100s of meters), no visual needed,
  could be corrupted by noise, i.e many people
  talking together (a protocol or code of
  conduct is required).

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Communicating Humans
From human presence on earth Some selected
examples

• Written
• Richness of language, not necessarily limited by
  distance, limited by encrypted form (must know
  script form). Must have pen and paper, or similar
  (not so natural). Can be corrupted by e.g. bad
  handwriting or spilling coffee on the paper
  (noise)
• Pigeon
• Not limited by distance much, but limited by
  volume,
• unreliable - message could easily be lost
• (pigeon is not necessarily reliable could go
  elsewhere, be eaten by a vulture, etc.)

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Communicating Humans (cont.)

• Smoke signals
• Limited by distance, need line of sight, limited
  by volume (rate of information transfer), limited
  by vocabulary-Smoke ON/Smoke OFF
• is this a big problem? Recall digital/binary
  communication
• limited by encrypted form (not many are smoke
  signal readerscould be an advantage. When?),
• can be corrupted by wind

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Communicating Humans (cont.)

• Morse code over electrical wires
• Not limited as much by distance,
• limited by volume over a given time period
  (information rate),
• limited by encrypted form (not many are Morse
  code readers),
• can be corrupted by electromagnetic noise, but
  not as easily as the smoke signal
• Radio signal (as in radio and TV)
• Not limited as much by distance,
• not limited as much by volume,
• not limited by encrypted form, but it is encoded
  (modulated),
• can be corrupted by electromagnetic noise (it
  touches upon quality of signal).

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Communicating Humans and communication channels

• Radio signals bounced on upper layers of
  atmosphere, or even satellites
• Not limited by distance--universe, not limited a
  lot by volume, can be influenced by weather
  conditions, can be influenced by position of
  satellite (geostationary, etc)
• Binary (digital) computer signals
• Not limited by distance by using repeaters, not
  limited a lot by volume, limited by encrypted
  form (not many are data signal code readers), not
  as easily corrupted by noise (if properly
  designed), offers reliable / dependable quality
• Light signals (optical fibers, light bulbs)
• Not limited by distance, not limited (at all) by
  volume, limited by encrypted form, not corrupted
  by e-m noise, offers reliable / dependable
  quality
• Light bubs
• Power lines

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Some indicative early systems

• Polybius (203-120 BC)
• Coding B21, S34
• 2 sets of 5 torches behind screens
• 2 torches up Ready-to-send / Clear-to-send
• Left screen, then right screen
• Bandwidth 2 words/minute
• Remained state-of-the-art for roughly 2000
  years

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Some indicative early systems

• Claude Chappe (1763-1805)
• 1792 Optical semaphore (arms telescopes)
• 2 arms x 7 positions x 4 bar positions 196
  symbols
• Operated by two people
• Can run full-duplex (but hard!)
• Delay Paris-Lille (190km) in 32 minutes
• Bandwidth 15 bits/minutes
• Most of the features of modern networks (routing,
  error correction, flow control)

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Some indicative early systems

• Electrical Telegraph Morse code
• 1837 Cooke and Wheatstone
• 25 characters/minute
• 1851 Paris London cable
• 1852 6400km cable in England
• 1866 London New York
• 20 words for 100

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Some indicative early systems

• Telephony (voice over wires)
• Reiss (1863), Bell (1876),Gray(1876),
  Edison(1877), Siemens (1878), ....
• This phone has way too many shortcomings to
  consider it as a serious way of communicating.
  The unit is worthless to us. Western
  Union,1876

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Next generation fibre optic communication
Fiber to the home - FTTH
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Light bulbs?

• What if every light bulb in the world could also
  transmit data?
• At TEDGlobal, Harald Haas demonstrates, for the
  first time, a device that could do exactly that.
  By flickering the light from a single LED, a
  change too quick for the human eye to detect, he
  can transmit far more data than a cellular tower
  -- and do it in a way that's more efficient,
  secure and widespread.
• To watch this video, please visit
• http//www.ted.com/talks/harald_haas_wireless_data
  _from_every_light_bulb.html

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Communicating Humans and communication channels
(cont.)

• What do the earlier examples have in common?
• Human adaptability and ingenuity in finding
  different (often unnatural) ways to communicate
  
• Different channels (guides) have been used (wind,
  air-space for pigeons, line-of-sight for smoke
  signals, radio waves, electricity signals, e-m
  waves, microwave guides, light (optical) waves
• Often to surpass limitations of the medium,
  encryption and noise cancelling techniques are
  used. At times information is piggy-backed on
  other more convenient signal (e.g radio
  modulation)
• Offered quality of service must be at acceptable
  levels
• To achieve our goal of effective and reliable
  communication, from anywhere, we need to study
  communication and networking (starting with the
  fundamentals)

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Networks

• So far we considered communication between 2
  points.
• What if we need to communicate with many? Do we
  need to establish one-to-one communication
  channels with each one? Is this
  efficient/practical/feasible?

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Networks

• Previous discussion focused on point-to-point
  communication.
• To be more effective and adaptable with our
  communication needs and to utilise resources
  efficiently, communication networks have been
  invented (recall other man made networks).
• Main innovation is
• aspect of sharing a common channel (e.g. in a
  Local Area Network) or a number of common
  resources (e.g. channels / nodes) and
• relaying (i.e. cooperating) messages for others
  (e.g. in the first Telephone system using
  (manual) switches, in the Internet using routers,
  in adhock (e.g. VANETS) and sensor networks with
  cooperation between the nodes)
• A world of interconnected IP (internet) devices
  leading to concepts such as the Internet of
  Things, Ambient Intelligence , etc...

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Networks

• Again, as in the choice of appropriate channels,
  whenever the need arises, different communication
  networks have been used, as the current needs
  dictate. Examples of different types of networks
  still in use
• The Telephone network,
• The cellular mobile Telephone Network (GSM, GPRS,
  UMTS, LTE, 4G)
• The Internet
• Cable networks
• Local Area Networks, Wireless Local Area Networks
• Sensor networks, Body Area Networks, Personal
  Area Networks, Vehicle Adhoc networks (VANETS),
  Home Area Networks,
• etc
• These networks may use different technologies,
  BUT fundamentals remain the same

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Networks

• Different networks and technologies require
  openness, interoperability, standards, protocols,
  etc
• Above will be part of the networking course
• Note for each one of the above volumes have been
  written, thousands of man-years invested by the
  community in research and development, but the
  results today have proven the worth of the
  investment. Notable examples include
• The telephone network which has enabled people to
  communicate from every part of the globe
• The Internet (a global network) which allows open
  access by the world community, from anywhere in
  the world, including mobile devices
• Worth pointing out that the internet is the most
  complex-large scale man-made system
• A view of the evolution of interconnected devices
• And to come, the Internet of Things and ambient
  intelligence
• Our aim is to cover the fundamentals, touch upon
  the technology, brief introduction to analysis of
  networks, hint upon traffic engineering and
  design issues, and open research questions and
  challenges. Most of our examples will be drawn
  from the internet.

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End
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Point to point connection
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Broadband over power lines ?IEEE spectrum Dept
2004
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Shared channel Network
Home WLAN network
Adhoc network
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Switching Systems

• Manual controlSwitch/cord boards

Off-Hook Indicator
Tip Ring
Patch Cord Pairs
Manual Ring
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Network
Common resources (e.g. routers)
Users
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routers
Cost?
From a few dollars to millions of dollars
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Internet devices
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Internet Map
This graph is using over 5 million edges and has
an estimated 50 million hop count.
http//www.opte.org/maps/
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Internet to the home - FTTH

• Google Fiber, offers 1 Gbps download speeds
  starting at 70 a month,
• https//fiber.google.com/about/
• Sonys new fiber-based ISP Nuro costs just 51
  a month and delivers lightning upload and
  download speeds of 1 Gbps and 2 Gbps,
  respectively.
• http//www.so-net.ne.jp/corporation/release/2013/p
  r20130415_2960.html

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Communicating vehicles (Vehicle Adhoc
Networks-VANETs)
Wireless links to other cars within hundreds of
meters
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Sensor Nodes
Many (could be thousands) nodes interconnected
via short range radio connections and relaying of
messages
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Internet of Things
Smart home
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Intels networking evolution perspective
http//www.bitrebels.com/technology/the-internet-o
f-things-every-device-that-connects-us-infographic
/
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Mobile devices
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