Transcript Not to spill out the juice with volume more than V 0

Series of lectures
“Telecommunication networks”
Lecture#01
Beginning of
telecommunication
Instructor: Prof. Nikolay Sokolov, e-mail: [email protected]
The Bonch-Bruevich Saint-Petersburg State
University of Telecommunications
Systems and Networks (1)
System is a set of interacting or interdependent entities forming
an integrated whole.
Telecommunication network is generally considered as
complicated system.
Complicated system is a system composed of many interacting
parts that can be studied using probabilistic models and
statistical methods.
Some main features:
•structure,
•control subsystem and controlled one,
•evolution.
Systems and Networks (2)
Input
Output
Instructions
Reports
A(t)
D(t)
Black box
B(t)
Controlled
subsystem
Management
C(t)
To carry
To take
Control
subsystem
Terminology: “to take – to carry” (1)
Three main statements:
•To accomplish the task within the time interval not exceeding
a certain threshold T0;
•Not to spill out the juice with volume more than V0;
•Not to allow penetration of strange substances with concentration over P0.
Terminology: “to take – to carry” (2)
Three main statements:
•To accomplish the task within the time interval not exceeding
a certain threshold T0;
•Not to spill out the juice with volume more than V0;
•Not to allow penetration of strange substances with concentration over P0.
Terminology: “to take – to carry” (3)
Three main statements:
•To accomplish the task within the time interval not exceeding
a certain threshold T0;
•Not to spill out the juice with volume more than V0;
•Not to allow penetration of strange substances with concentration over P0.
Terminology: “to take – to carry” (4)
Telecommunications system functions during
the transfer of the information between points
and can be represented by three statements:
•To deliver information within a perceptible time, not
exceeding the threshold T0;
•Not to lose a perceptible part of the information,
allowing the loss being not more than V0;
•Not to allow distortion of the information over the
level P0.
Earliest methods of communications
•Whistle (sound),
•Fire,
•Smoke,
•Smell,
•Mark (pictures),
•etc.
Snail Telegraphy (1)
Type of signal propagation is unknown.
Snail Telegraphy (2)
French occultist named Jacques Toussaint Benoit was
convinced that any two snails that had once mated
remained forever in telepathic contact, no matter the
distance between them. Touch one, and its mate would
move. Based on this principle, Benoit devised a pair of
contraptions consisting of 24 snails glued to the bottom of
a bowl, each representing a different letter of the
alphabet. Each snail’s mate was affixed, with a
corresponding label, to a receiving device that could be
installed anywhere in the world. “Space was not
considered by snails…” writes Sabine Baring-George in
the 1889 book Historic Oddities and Strange Events.
Acoustic Mirrors Across the Channel
The massive concrete acoustic mirrors, or “listening ears,” lining the southeast
coast of England were built between the world wars to monitor the skies for the
telltale sounds of airborne invasion. The Sound Mirrors Project plans to
construct two such acoustic mirrors on opposite sides of the 25-mile-wide
English Channel, precisely positioned so as to allow international parabolic
communication.
Optical telegraph (1)
Claude Chappe
The semaphore or optical telegraph
is an apparatus for conveying
information by means of visual
signals with towers with pivoting
blades or paddles, shutters, in a
matrix, or hand-held flags, etc.
Information is encoded by the
position of the mechanical elements.
It is read when the blade or flag is in
a fixed position. In modern usage it
refers to a system of signaling using
two handheld flags.
Optical telegraph (2)
Important milestone
Earliest methods of
communications
Electrical
communications
Electrical communications (telecommunications) is the branch of electrical
engineering dealing with the transmission and reception of information.
Information can be transmitted over many different types of pathways, such as
satellite channels, underwater channels, telephone cables, and fiber-optic links.
Characteristically, any communications link is noisy. The receiver never receives
the information-bearing waveform as it was originally transmitted. Rather, what
is received is, at best, the sum of what was transmitted and noise. In reality, what
is more likely to be received is a distorted version of what was transmitted, with
noise and perhaps interference. Consequently, the design and implementation of
a communications link are dependent upon statistical signal-processing
techniques in order to provide the most efficient extraction of the desired
information from the received waveform.
First steps (1)
Hans Cristian Ersted
Modern electronic
communications, everything
from the telephone to the
internet began as a result of a
chance observation in 1819.
Hans Christian Ersted, a
Professor of Natural
Philosophy in Copenhagen,
Denmark, was giving a
lecture to his class on the
subject of electricity; at that
time, a new and exciting
discovery was made.
First steps (2)
André-Marie Ampère
André-Marie Ampère was a
French physicist who is generally
credited as one of the main
discoverers of electromagnetism.
The SI unit of measurement of
electric current, the Ampere, is
named after him. Ampère's fame
mainly rests on the service that he
rendered to science in establishing
the relations between electricity
and magnetism, and in developing
the science of electromagnetism,
or, as he called it,
electrodynamics.
First steps (3)
Baron Pavel L'vovitch Schilling was a diplomat of Baltic German
origin in service of Russia in Germany who constructed a
revolutionary new telegraph, consisting of a single needle system
in which a code was used to indicate the characters.
First steps (4)
Wilhelm
Eduard Weber
Wilhelm Weber was the second of
three brothers, all of whom were
distinguished by an aptitude for the
study of science. In 1831, on the
recommendation of Gauss, he was
called to Göttingen as professor of
physics, although but twenty-seven
years of age. His lectures were
interesting, instructive, and
suggestive. Gauss and Weber
constructed the first electromagnetic
telegraph in 1833, which connected
the observatory with the institute for
physics in Göttingen.
First steps (5)
Johann Carl
Friedrich Gauss
Johann Carl Friedrich Gauss was a
German mathematician and scientist
who contributed significantly to many
fields, including number theory,
analysis, differential geometry,
geodesy, electrostatics, astronomy,
and optics. Sometimes known as "the
prince of mathematicians" and
"greatest mathematician since
antiquity", Gauss had a remarkable
influence in many fields of
mathematics and science and is
ranked as one of history's most
influential mathematicians.
First steps (6)
Samuel Morse
Samuel Finley Breese Morse
(April 27, 1791 – April 2, 1872)
was an American painter of
portraits and historic scenes,
the creator of a single wire
telegraph system, and coinventor, with Alfred Vail, of the
Morse Code. He was a generous
man who gave large sums to
charity. He also became
interested in the relationship of
science and religion and
provided the funds to establish
a lectureship on “the relation of
the Bible to the Sciences”.
First steps (7)
Alexander
Graham Bell
Alexander Graham Bell was called
"the father of the deaf". With both his
mother and wife deaf, he studied
hereditary deafness in order to better
understand the affliction. His research
on hearing and speech led him to
experiment with hearing devices that
eventually culminated in the telephone.
Bell was awarded the first U.S. patent
for the invention of the telephone in
1876. Although other inventors had
claimed the honor, the Bell patent
remained in effect.
First steps (8)
Phone designed in 1885
Pavel Golubitsky
Pavel Golubitsky was one of the
first Russian specialists in the
field of telephony.
First steps (9)
Alexander Popov
Alexander Stepanovich Popov was a
Russian physicist who was the first
to demonstrate the practical
application of electromagnetic
(radio) waves, although he did not
care to apply for a patent for his
invention. Beginning in the early
1890s he continued the experiments
of other radio pioneers. In 1894 he
built his first radio receiver, a
version of the coherer. Further
refined as a lightning detector, it was
presented on May 7, 1895 — the day
has been celebrated in the Russian
Federation as "Radio Day".
First steps (10)
Guglielmo Marconi
Guglielmo Marconi (25 April
1874 – 20 July 1937) was an
Italian inventor, best known for
his development of a
radiotelegraph system, which
served as the foundation for the
establishment of numerous
affiliated companies worldwide.
He shared the 1909 Nobel Prize
in Physics with Karl Ferdinand
Braun, "in recognition of their
contributions to the
development of wireless
telegraphy".
International Telecommunication Union
ITU is the leading United Nations agency
for information and communication
technologies. As the global focal point for
governments and the private sector, ITU's
role in helping the world communicate
spans 3 core sectors: radiocommunication,
standardization and development. ITU also
organizes TELECOM events and was the
lead organizing agency of the World
Summit on the Information Society.
ITU is based in Geneva, Switzerland, and
its membership includes 191 Member
States and more than 700 Sector Members
and Associates.
ETSI
ETSI was created by CEPT (European
Conference of Postal and
Telecommunications Administrations)
in 1988. Based in Sophia Antipolis
(France), ETSI is officially responsible
for standardization of Information and
Communication Technologies (ICT)
within Europe. ETSI has 696 members
from 62 countries/provinces inside and
outside Europe, including
manufacturers, network operators,
administrations, service providers,
research bodies and users — in fact, all
the key players in the ICT arena.
Maslow's Hierarchy of Needs (1)
Abraham Maslow
developed the
Hierarchy of Needs
model in 1940-50s
USA, and the
Hierarchy of Needs
theory remains
valid today for
understanding
human motivation,
management
training, and
personal
development.
Telephone conversations
Maslow's Hierarchy of Needs (2)
Homework
To find information related to
telecommunication history in
your country (using Internet).
Instructor: Prof. Nikolay Sokolov, e-mail: [email protected]