Transcript From Smoke Signals to the Internet: The History of

From Smoke Signals to the Internet:
The History of Communications
Infrastructures
Randy H. Katz
United Microelectronics Corporation Distinguished Professor
Electrical Engineering and Computer Science Department
University of California, Berkeley
© 2005
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History of Communications
• The Dream:
– The Crystal Ball
– Information anywhere, anyplace, anytime
– Power of kings, nation states, business cartels
• First examples of state-sponsored R&D
• Creative destruction: new supersedes the old
• Scientific discoveries leading to practical
applications--a $1 trillion/year industry
• Brilliant inventors and large corporations
• The ever present legal system
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Muscle Powered Communications
• Human messengers on foot or horseback
– “Command and Control” between capital and the field
– 490 BC: Phidippides runs from Marathon to Athens to
report victory over the Persians (26.2 miles)
– 14 AD: Roman relays—50 miles per day for regular
mail, 100 miles per day for express mail
– 1280 AD: Kublai Khan—200-250 mi per day
“Poste Haste”— “Fast Post” —riders signal by horns
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Visual Communications
• Heliographs
– Flashing Mirrors
• Flags
– The Howe Code
British RN, 1790 AD
– 10 colored flags
260 numbered entries
Semaphore
Flags
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Visual Communications
• 1803: The Popham Code, aka Trafalgar Code
– 10 flags representing A-K (I,J same) and numerals 0-9
– 15 combinations of 2 flags for the rest of the alphabet
– Code book of 3000 numbered phrases represented by
4 flags (indicator flag plus 3 numeral flags)
• Horatio Nelson: “England expects every man will
do his duty”
– 7 hoists of 4 flags
– 1 flag hoist for “D”
– 2 flag hoists each for “U”, “T”, “Y”
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Fire Beacons
150 BC: Polybius, a Greek historian, documents first known
system for transmitting arbitrary messages
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1 2 3
A B C
F G H
L M N
Q R S
V W X
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D
IJ
O
T
Y
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E
K
P
U
Z
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The Optical Telegraph
• Claude Chappe, 1763-1805
Early Defense
Contractor
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The Optical Telegraph
Emergence of a Network
– 1799: Napoleon seizes power
“Paris is quiet, and the good
citizens are content.”
– 1814: Extends from Paris to
Belgium and Italy
– 1853: 3000 miles, 556 stations
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Scientific Advances
• Late 18th—Early 19th Century
– Increasing evidence of the close relationship between
electricity and magnetism
– Oersted (Copenhagen): demonstrated electricity’s ability
to deflect a needle
– 1831, Faraday (Royal Institution, London): demonstrated
electromagnetic induction, the basis of electric motors
Politician: “But what’s the use of it, Mr. Faraday?”
Faraday: “Ah, but what use is a baby?”
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The Electrical Telegraph
• Wheatstone and Cooke,
Railroad Telegraph, 1837
– 14 mi installed by 1838
– 4000 mi by 1852
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The Electrical Telegraph
Samuel Morse,
Morse Code, 1837
– 1838: demonstrated
over 2 miles
– 1844: US sponsored
demonstration
Baltimore between
Washington DC
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Dots and Dashes Span the Globe
– 1852: First international
telegram
– Reuters establishes
“Telegraph News Network”
– 1858: Cyrus Field lays first
transatlantic cable
» US President & Queen Victoria
exchange telegrams
» Line fails in a few months
– 1866: New cable &
technology developed by
Professor William Thompson
(Lord Kelvin)
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Dots and Dashes Span The Globe
• Communications “arms” race in the Imperial Age
– No nation could trust its messages to a foreign power
– 1893: British-owned Eastern Telegraph Company and
the French crisis in Southeast Asia
– 1914: British cut the German overseas cables within
hours of the start of WW I; Germany retaliates by
cutting England’s Baltic cables and the overland lines
to the Middle East through Turkey
• Strategic necessity: circumventing the tyranny of
the telegraph lines owned by nation states
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Scientific Background
James Clerk Maxwell (1831-1879)
"... we have strong reason to conclude
that light itself -- including radiant heat,
and other radiations if any -- is an
electromagnetic disturbance in the form of
waves propagated through the
electromagnetic field according to
electromagnetic laws." Dynamical Theory
of the Electromagnetic Field, 1864.
Heinrich Hertz (1857 - 1894)
– Mid-1880s: Demonstrated experimentally
the wave character of electrical
transmission in space
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Wireless Telegraphy
Guglielmo Marconi
– 1895: 21 year-old demonstrates
communication at distances much
greater than thought possible
– Offers invention to Italian
government, but they refuse
– 1897: Demonstrates system on
Salisbury Plain to British Royal
Navy, who becomes an early
customer
– 1901: First wireless transmission
across the Atlantic
– 1907: Regular commercial service
commenced
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Wireless and Warfare
“Portable” radio, circa 1915
Airborne radio telephone,
post WW I
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The Telegraph Learns to Speak
Alexander Graham Bell
– 1876: Demonstrates the telephone at US
Centenary Exhibition in Philadelphia
– Bell offers to sell patents to Western Union
for $100,000--they refuse. Bell Telephone
Company founded 9 July 1877
– 1878: Western Union enters into competition
with rival system designed by Thomas
Edison and Elisha Gray. Bell sues and wins.
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Bell’s Early Telephones
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Building the Network
Almon Brown Strowger (1839 - 1902)
– 1889: Invents the “girl-less, cuss-less”
telephone system, aka the mechanical
switching system
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Bell Telephone
Equipment
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Making the Airwaves Sing
John Fleming (1849-1945)
– 1904: invents the diode; used
as a radio detector
Lee DeForest (1873-1961)
– 1906: invents the audion, a
vacuum tube that both
amplifies and detects -replacement for Marconi’s
spark gap generator
– 1910: First music broadcast
from Metropolitan Opera
House; first demonstration of
radio telephone
– 1916: Operates radio station
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Scientific Genius of Radio
Edwin Howard Armstrong
– 1912: Regeneration
» Exploits feedback to improve reception
sensitivity -- DeForest sues over who
invented amplification, and wins in 1928
– 1918: Superheterodyne Reception
» Special mixing circuit enables higher
frequencies for radio transmission
– 1921: Superregeneration
» New circuit that achieves extremely high
levels of amplification
– 1933: Frequency Modulation (FM)
» Crystal clear reception possible by encoding
sound in waveform frequency rather than
amplitude
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Commercial Genius of Radio
David Sarnoff and RCA
– 1912: Marconi operator
communicating with the Titanic
survivors; Marconi’s personal assistant
– 1916: Proposed “radio music box”
– 1919: Marconi Company in US
becomes RCA
– 1920: First radio station, KDKA
Pittsburgh
– 1922: RCA spins off NBC
– 1930: 40% of US homes have radios
– 1938: 82% have them
– RCA stalls development of FM
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Early Communications Devices
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Seeing at a Distance: Television
Mechanical Approaches
– 1883: Nipkow disk
– John Logie Baird
» 1925: marries Nipkow disk to radio;
demonstrates system at Selfridge’s
Department Store in London
» 1928: transmits image across Atlantic
» 1929: BBC commences regular
broadcasts (3 half hours per night,
beginning at midnight)
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Electrical/Mechanical Systems
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Forgotten Genius of Television
Philo T. Farnsworth
– 1921: As 14 year old, has vision
of horizontal scanning
– 1922: Develops electronic
camera
– 1926: Sets up Green Street lab
– 24 August 1928: Demos first all
electronic TV system
– 1930: RCA’s Zworykin visits
Farnsworth’s Lab
– 1931: Patents sold to Philco
– 1935: Wins patent battle with
RCA; refuse to sell, takes
license fees instead
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Philo T. Farnsworth
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Packet Switching
Paul Baran
– Early 1960s: New approaches
for survivable comms systems
needed; “hot potato routing” and
decentralized architecture
Donald Davies
– Coins the term “packet”
ARPANet
– 1967: Connect computers at key
research sites across the US
using pt-to-pt telephone lines
– Interface Message Processors
(IMPS)
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ARPANet Becomes Internet
Robert Kahn and Vint Cerf
BBN team that implemented
the interface message processor
– 1973-5: ARPANet + Packet
Radio Net + Satellite Net
leads to a “network of
networks”: TCP/IP protocols
– 1981: Berkeley UNIX first
open implementation of the
TCP/IP protocols
– 1983: Extended to CSNet
and then NSFNet
– 1990s: NSF privatizes the
Network; ISPs take off
– 1993-4: The World Wide
Web takes off
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What Comes Next?
• Convergence
– More than 50% of bits on voice network are data, not
digitized voice
– Everything is becoming digital; anything can
transported over anything; bits are bits
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WebTV vs. Video PC
Satellite TV vs. cable TV
Video over telephone lines vs. telephony over cable TV
Data over cellular telephones
Wireless local loop
– The Battle for the Eyeballs
» Video on demand vs. Internet access
» Broadcast entertainment (“push”) vs. web browsing (“pull”)
– “Is this a great time or what?” MCI ad
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What Comes Next?
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