The beginning of the telephone system
1837-invention of
Morse’s Telegraphy.
The basic telegraphs-1837
In 1820 Mr.Oersted of Denmark found that:
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There was a magnetic field around a wire carrying an electric current.
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When the wire is coiled to have N turns, then the magnetic field along its axis is N times greater.
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If a piece of iron is inserted within the coil, the magnetic field further increased by a factor of 1000.
This constitutes the principle of a relay. In its tern a relay can make or break other electric circuits. The telegraph is based on this idea. One Mr. Henry of Newyark discovered that the relay could operate even when the wire was over three Kilometers long.
Samuel Morse, an amateur scientist along with his student Alfred Vail put the existing idea together and evolved a system to communicate over long distances. They also invented the Morse code by which all alphanumeric characters could be represented by a combination of dots and dashes. It was a remarkable break through in long distance communication, the first in the world.
The first Telegraph line came in India in 1853. London was connected to Calcutta in 1871 by over head line.
1852- Telegraph service started in India.
1868- Europe had been connected with India by telegraph
lines.
1876-The telephone was invented in USA.
1881-The Oriental telephone company, was licensed to open
telephone exchanges in India.
1882- First Telephone exchange was opened in Calcutta,
Bombay, Madras and Ahmadabad.
The central exchange Calcutta had 93 subscribers.
1907-First central battery telephone exchange installed at
Kanpur.
In 1914, on the eve of the First World War, the next big
administrative changes had come. The Postal Department and the Telegraph
Department were amalgamated under a single Director-General.
1913-14- Automatic telephone exchange opened in Simla, [HimachalPradesh].
1927-Radio Telegraphy started between India and UK.
1933-Radio telephony started between UK and India.
1953- A 12 channel carrier system was installed for trunk
working in India.
1960- The S.T.D.
service between Lukhnow and Kanpur was commissioned.
1972- The telecommunications accounts were separated from
that of post offices.
1975- First PCM system installed between Bombay and Andheri,
for local junction working.
1979- The OFC [Optical fiber cable] system was installed at
Pune, for local junction working.
1984- C-DOT [committee on development of Telematics]
established for manufacture of digital switches.
After gaining independence from Britain in 1947, the
national government continued the colonial legacy, organizing post and
telegraph services exclusively in the domain of the state.
I was appointed as Telephone
operator during the year 1974 and was posted to a CBNM telephone exchange at
Bhalki in Bidar district of Karnataka state. A trunk line circuit was available
along railway line from Bhalki to Bidar and a three channel carrier system was
built on it for trunk working. We used to put through calls for public using
ticket booking system.
When I had a little experience, I
was made H.T.O. [head telephone operator] as all seniors got transferred to
other locations. Electro-magnetic relays were used for signaling the subscriber
line indicators. All calls switching was done manually, including local calls.
Many village Public call offices [PCOs] were terminated directly on the trunk
board. This was the beginning of communication in rural and district head
quarters. The Number of Telephone connections at Bidar city were about 300 and
at Gulbarga, it was 700 telephone lines. Telephone revenue accounts office was
opened at Gulbarga. DET was the head of telecom management for Gulbarga
division. Most of the village population in this region, did not understand
what the telephone was. The telephone usage was limited to business community
and VIPs and public offices like police station, hospital railway station etc.
ITI Bangalore was the place where the network switches were manufactured for
south India. The large cities had automatic exchange switches. The Mysore city
had cross-bar switching exchange.
One person [Telephone
Operator] had to work at a time to connect the people for local and trunk
service needs of communication. Yes it was the beginning of telephone services
to people. All calls were handled manually. The dedicated staff used to work
day and night in shifts, to serve the need of the public. The government, the
polish, the trade and the public were dependent on this simple system.
People used to wait in queue, to get their turn, to talk to
for-off places on trunk routes. Trunk Calls were booked and tried on priority.
Signaling and voice were used to pass call switching information between
stations. The system worked with frequent interruptions, due to trunk lines
failures and all that.
Up gradation started in the system[1980s]
The departmental own buildings came up in five years.
The local exchange automatic switching machines were
installed. They were all mechanical switches working on electromagnetic
principles [the Strowger switching exchanges].
More number of trunk-channels were installed, to connect
trunk-calls quickly.
The working force was the line men, the operators and the
technicians for different works apart from supervisors and engineers. The
divisional and sub divisional offices managed the system operation and
maintenance and developments. Officers were highly respected for their caliber.
Public call offices [PCOs] were opened for a cluster of
villages in a local area. Then the villagers could use the phone services on
emergency. The system expansion started at district places. The number of lines
increased, so also the supporting staff. All this happened around 1980.
Large scale recruitments started for junior engineers in
DOT. One more high tech cadre of district managers was created with modern
know-how on communication systems.
After 1980s the microwave trunk routes were planned and installed,
started working by 1985. This changed the game of connecting calls on demand.
Even the STD services were started immediately for important customers. STD
PCOS were opened for instant call connection. The technical and revenue
assessing works were upgraded. By 1990 the electronic switching systems were
being manufactured in Bangalore. Gradually replacement of old mechanical
switches by electronic switches was taken up at district places. This changed
the game again, so that new connections could be provided to the desired
customers on demand by laying additional local cables. The system expansion was
an easy method and could be done with lesser time lapse. Connections started
increasing gradually. The call switching failures were minimized.
The technical staff called technicians, who used to maintain electro-magnetic switching
units had become surplus. The trunk calls connecting operative staff also became surplus. These two important cadres
have lost their impotence. This and also open-line maintaining line-staff too
became a vanishing cadre. These people were used for other maintenance and
developmental activities. A new cadre called phone mechanic was introduced for
external works in the field units. The RSA [repeater station assistant] cadre
was also vanished. The Junior Engineer
cadre became the important technical staff. This was an important phase change
in the DOT.
Optic fiber networks were established to interconnect
exchanges together. The operator was no longer needed so also the technician
was eliminated. The long distance open-wires maintaining line staff was
eliminated. It was only high tech people like engineers and clerical staff was
needed. For maintaining local cables local phone mechanics were retained. This
changed the entire system architecture to high tech. This thing went up to
2000.
The advent of mobile technology made a competitive
environment and parliament passed the telecom policy bill to privatize the
telecom system and therefore multiple operators’ entered the scenario, as
service providers. The competitive environment started and the DOT officers had
become a multi-switch to do all things together. Most of the seniors [officers]
retired. Some confusion prevailed since the adoption into new working method
was somewhat changed. The red tape privilege vanished for DOT workers. It was
like do-or-die situation. Some of the senior officers became illiterate before
their juniors due to high-tech working environment.
From a simple open-wire lines system, to microwave trunks
and OFC cables, it became high-tech function. Digital switching units replaced
most of the manpower. The junior-engineer was the only working cadre
which was needed. Other higher officers were only the managers, like district
manager, zonal manager, and circle manager and so on. Even revenue assessing was automated. The game
was changed to minimum staff.
This was a journey of 1970 to
2000, a span of three decades. I witnessed all these drastic changes in my
service in the DOT India. What a wonder! Really a large leap in communication
methodology happed in the world, at the time when we entered into 21st
century. The era of internet and internet banking and all that were value
adding services! Of modern communication networks.
