Lecture#01

Beginning of telecommunication

The Bonch-Bruevich Saint-Petersburg State University of Telecommunications

Series of lectures “Telecommunication networks”

Instructor: Prof. Nikolay Sokolov, e-mail: sokolov@niits.ru

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)

Control subsystem

Controlled subsystem

Instructions Reports

Black box

Input Output

A(t) D(t)

B(t)

Management C(t)

To

take

To

carr

y

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

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.

Earliest methods of communications

Electrical communications

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 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 co-inventor, 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”.

Samuel Morse

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)

Pavel Golubitsky was one of the first Russian specialists in the field of telephony.

Pavel Golubitsky

Phone designed in 1885

First steps (9)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".

Alexander Popov

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 UnionITU 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.

Maslow's Hierarchy of Needs (2)

Tel

eph

one

con

vers

atio

ns

Instructor: Prof. Nikolay Sokolov, e-mail: sokolov@niits.ru

Homework

To find information related to telecommunication history in your country (using Internet).