Telecommunications: Messages from afar

New discoveries of past centuries

The 19th century was a time of great change in the world. New countries, new discoveries, and new inventions were changing the way people worked and the way they lived. Tools and machines like the mill-wheel had been known for a long time, but scientists were learning to harness unseen energies that could change machines in wondrous ways.

Scientists were excited about the new discoveries. They read of journeys to new lands and studied new maps. They made new studies of the earth, and tried their experiments with new compounds and chemicals. They discovered how to control physical changes in gases and metals by heat, light and magnetism, in an exciting branch of science known as Physics, and they learned about the power that was called Electricity.


The first electrical engineers

Scientists had known of electricity for a long time. They learned ways to control and use this force. They read of other experiments. and did the tests themselves. The names of these pioneers are many, and each scientist learned something from the earlier inventors, such as Guericke, Franklin, Galvani, Ampere, Volta, Faraday, Ohm, Cooke, Maxwell, Swan, Henry, Morse, Bell and Edison.

Joseph Henry was the first secretary of the Smithsonian Institute in America, long famous for its connection with science. It was Henry who invented the electric motor, and paved the way for many practical uses of electricity. Joseph Henry believed that scientific discoveries belonged to everyone. He gave great help to two men who were trying to send electric signals by wire. They were Charles Wheatstone of England, and an American called Samuel Morse.


The Pioneers

GUERICKE 1602-1686  Vacuums, first frictional electrical machine, Leyden jar.

FRANKLIN 1706-1790  Proved lightning was a form of electricity.

GALVANI  1737-1798  Used electricity to activate muscle in frog legs.
 
VOLTA    1743-1827  Invented the electric battery.

AMPERE   1775-1836  Theory of solenoids, originator of electrodynamics.

OHM      1787-1854  Current & Resistance ( Ohm's law).

FARADAY  1791-1867  Electrolysis, Electric transformers.

MORSE    1791-1872  Developed Morse Code used in telegraphy.

HENRY    1797-1878  Electric motor, electromagnets.

SWAN     1828-1914  Carbon electric light filaments, photographic plates.

MAXWELL  1831-1879  Mathematics of electromagnet wave formation.

BELL     1847-1922  Inventor of voice transmission ( telephone ).

EDISON   1847-1931  Improved telephone, perfected phonograph, electric light.

TESLA    1856-1943  Developed the use of alternating current.

HERTZ    1857-1894  Verified Maxwell's theories of electromagnetic waves.

Morse and his messages

Two things helped Samuel Morse to be a success. One was the simplicity of his code. The other was his ability to convince other people that his ideas were worth supporting. He convinced Joseph Henry that his ideas were sound, and he convinced the American Congress to pay for a telegraph line.

The simple Morse key sent electrical pulses - long and short - along a wire, where a moving stylus marked the signals on a strip of paper. The signals were given in carefully measured dots and dashes. A space as long as a dot was left between the separate pulses in each letter, and a space as long as a dash was left between letters. The space for five dots was left between words.

The code was simple and easy to master, and in May 1844, Morse used this system to send a message between Baltimore and Washington - a distance of about 64 kilometres. The Morse code was so simple that most people could learn it, and it was adopted almost world wide. A skilled operator could send messages at the speed of thirty words a minute.


Morse telegraphy in Australia

Morse taught telegraphy to others, and one of his students saw a great future for telegraphy in the young land of Australia, where gold had just been discovered.

Samuel Walker McGowan heard of the gold discoveries in Australia and brought to Melbourne several sets of Morse instruments, and an electrician, as well as the batteries and insulators he would need to give a demonstration. In June 1853, he gave a public demonstration of Morse telegraphy, hoping to set up a private company to link the cities to the goldfields.

But the colonial government decided to make the telegraph public, and set up an experimental line between Melbourne and Williamstown. McGowan was appointed general superintendent of Victoria's Electric Telegraph Department, and the line was open for public service.

In the first year alone, some 4000 telegrams were sent, and this figure more than tripled in two years.


The spread of telegraphy

Australia was a land of vast distances, almost no roads, and isolated communities. Yet wherever the news of gold travelled, so did the people and so did the telegraph.

Like a wire web, the telegraph cris-crossed the country, linking cities and goldfields. In six years at least four of the colonies were linked by telegraph line, while Tasmania had its own network and had already made two attempts at linking with the mainland.

By August 1872 the famous Overland Line linked Adelaide to Darwin and then a further line through Java gave Australia contact with the rest of the world. By 1877, an east-west link had been made between Port Augusta and Albany.

At the turn of the century the Morse system covered more than 20,000 miles (approximately 32,000 km) of Australia. This gave Australia a head start in another kind of telecommunications - voices over wires.


Voices over wires

There were many new electrical experiments, and each one was very important, but one changed the world, and is still changing the way we work and live. This was Bell's experiment that allowed voices to travel along wires.

Australians were already using telegraphy, and it was sensible to use the telegraph lines to experiment with Bell's new invention. In 1877, J. W. Thomas of the Geelong Customs House experimented with home made telephones between local houses. The first test over telegraph lines took place on January 9, 1878, between Geelong and Queenscliff.

In less than two years the first long-distance telephone calls were held between Semaphore and Port Augusta, (400 km) and between Sydney and Maitland (225 km).


One phone one line

The first telephone calls were point to-point. This means that only one telephone used the wire and the call went to one place.

As telephones became more common, more people wished to call each other. Each of these calls needed its own line. This could not work very well at all, as it required too many wires in all directions. The way to connect every caller with every other caller was to set up an "exchange'' where calls could be switched from one line to another.

Every telephone was connected to the exchange, and the operator at the exchange then linked the two parties who wanted a connection. The first commercial exchange was in America, in 1878.

Again, by 1880, only two years after the world's first telephone exchange was built, Australia had her own telephone exchanges in Melbourne and Brisbane, and one in Sydney in 1881. Adelaide and Hobart followed in 1883 and the Perth Exchange opened in 1887.


A new century

By the start of the new century, many changes were making telecommunications faster and easier. Women were being trained as switchboard operators in the exchanges, and the telephone service grew almost every day.

In Italy, Marconi experimented with radio, and in 1896 patented his Wireless telegraphy by radio waves. This meant that morse could be transmitted to ships at sea, to other lands, to remote places where no wires had reached.

In 1900, Wheatstone invented an automatic Morse transmitter that could send 400 words a minute. These two inventions added many new possibilities to telecommunications. Customers wanted more connections and they wanted them faster.

Trunk lines were set up to connect exchanges with other exchanges. In 1907 the first trunk line between capital cities opened, between Sydney and Melbourne.

New developments came quickly. In 1912, the first automatic telephone exchange for public use was opened at Geelong. It was the first in the Southern Hemisphere, and the second in the whole of the then British Empire.


The world in touch

The radio had been improved. Voices could be transmitted by radio waves. Radio-telephones were now possible. And with each new step, more people saw how useful it was to be able to communicate across great distances.

The speeding telegraphs were connected to teletype machines that printed the messages. This was the start of the telex network that played such a big part in modern business communications.

Photography too was making its own path. Picturegrams were sent from city to city as early as 1929, and this was very useful during the 1956 Olympic Games. Nowadays, nearly all companies have their own facsimile equipment. They simply connect it to the Telecom network.

Radio-telephone links were set up between Australia and England, while the pedal radio brought doctors to help lonely outback settlers.

Tasmania was connected to the mainland by the (then) longest submarine telephone cable in the world. By 1946, Australia had a Commission (OTC) to look after its overseas telecommunications. In one lifetime the number of telephones in Australia grew from none at all to half a million.


Service: demand and supply

Because Australia has a small population spread so far apart, it has always been a problem to serve all of the people fairly. At the same time, most of the people live in the coastal areas. This means the demand is greatest in those areas.

Television was another of the newer inventions to bring messages from afar. It, too, relied on cables to relay pictures from one state to another.

One way to handle this problem was to have lines and equipment that would handle as many applications as possible. A coaxial cable was laid, which could handle a large number of different jobs.

In 1959 the first broadband trunk system in Australia, a microwave radio link, opened between Melbourne and Bendigo. Broadband networks allow telephone conversations, telegrams and television programs to be transmitted.

A special cable through Vancouver in Canada carried messages to the United Kingdom, and all the countries in between. Australian could send 80 phone calls around the world, all at the same time! By 1967 cables linked Cairns to Singapore, and today Australia has a broadband telecommunications network ready for the needs of the future.


Computers, satellites and a shrinking planet

The new equipment that made this possible also made other changes possible. Computers had been useful tools for calculating and measuring. Now they were smaller, using less power, yet becoming more powerful. They held more information than human memories, and could be connected by telephone. The age of computerised telecommunications had arrived.

Computers transmit information with such speed that they are widely used in business. The switches to link these machines also need great speed. Switching was forced to become computerised, by the demands of the network. So computers linked computers in a web of telecommunications, switching messages with a speed and accuracy that was almost magical.

In 1967, Australia received new messages from space - further than ever before.

Satellites in special orbits transmitted signals from North America, and a year later the Australian network was linked to a global service, using the OTC Earth Station at Moree.

In 1983 Austpac provided digital communication services and in 1985 Australia launched AUSSAT, its own domestic telecommunications satellite, where Telecom's Iterra Satellite Services provided services across the nation.

In 1992 the Telecom half a billion dollar Rural and Remote Program provided every Australian no matter how remote, with a modern automatic telephone service.


Future telecommunications

Australia is poised on the brink of a remarkable telecommunications future.

Current research is leading towards a world of radically transformed services for every level of Australian society. Fuelling the dramatic changes is not just the new technology but a strong commitment to providing network capabilities that meet people's needs to communicate.

Through Telecom Research Laboratories in Melbourne, Australia is at the international forefront of the developments that will make Australian telecommunication service more visual, intelligent and personal.

These advances will not occur by chance. Throughout the 1980s and early 90s, high capacity, optical fibre cables have been laid between all capital cities and in that part of the network that interlinks telephone exchanges.

One of the results of this upgrade is the advent of one of the world's first Broadband Integrated Services Digital Networks, or Broadband ISDN. This network allows different services, such as fax, voice and data to be integrated into a single transmission and accessed through a single "plug on the wall". Broadband-lSDN will be capable of speeds of over 150 million bits per second - fast enough to send a 100 page fax in a fraction of a second and the integrated transmission of broadcast quality and high definition TV.

The consequences of this leap forward in network capability will be as profound and revolutionary as the advent of the telephone was 100 years ago.

For home users Broadband ISDN will make possible Dial a-Video, Dial a CD, video enhanced electronic mail, high quality videotelephony and shop from home services. The concept of telecommuting or working from home via a communications link will become a workable proposition for many.

Desktop-to-desktop videoconferencing will be possible which will in turn lead to more productive staff work time by reducing the time spent travelling to and from meetings.

In medicine, new diagnostic services will allow doctors to assess X-rays, CAT scan and other medical imagery from afar.

The mobile office will become a reality as business people have the ability to send and receive voice calls, faxes and computer data.

After the turn of the century these radio based technologies will be married to Broadband- ISDN to fulfil one of the ultimate destinies of telecommunications - Universal Personal Telecommunications, or 'UPT'. Customers will be provided with a single personal number for all the services they want to receive instead of different numbers for the home, office, fax machine, mobile phone or for any other location or future service.

With the ever accelerating pace of change in telecommunications one thing is certain - the telephone of tomorrow, with all its capabilities, will bear little comparison to the telephone service that we use today.


Source: http://www.telstra.com.au/prod-ser/educdocs/educdocs/telecomm.html

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