Friday 24 June 2011

Telecommunication introduction


Introduction to Telecommunications provides students with the fundamental background knowledge in the theory, mediums of transmission, topologies and functions of systems used in businesses and Smart Homes. Students assemble, test and troubleshoot audio, visual, IR, wired and wireless connectivity systems to explore these principles.
During this 40-Hour course students are also familiarized with on the job safety procedures to ensure personal protection and protection of networking devices. Upon successful completion of this program students are eligible for certification.
Students apply their knowledge by using C-Tech's Interactive Telecommunications Board (ITB). This innovative teaching aid contains simulated 4-pair data systems, coaxial cable systems, and a fiber optic system all in one compact mobile unit.
Students use electronic testing equipment in conjunction with the ITB and then go on to:
  • Test and verify the operation of connectivity systems
  • Develop block diagrams to represent systems connectivity
  • Perform a "Tone and Trace" on a copper cabling system
  • Perform an optical continuity test on an optic system
  • Troubleshoot a malfunctioning system
Technology Learning Activities throughout the text provide opportunities for students to couple their knowledge with creativity in solving communications problems drawn from real-world scenarios.
Throughout the program, system integration, operation, problem-solving and analysis are emphasized, along with the ability to relate real devices to the concrete realities they depict.

Deregulation and the establishment of Telstra

Deregulation and the establishment of Telstra

In Australia the 1982 Davidson Enquiry regarding private sector involvement in delivery of existing/proposed telecommunications services recommended ending Telecom Australia's monopoly. In the preceding year Aussat Pty Ltd, another government agency, had been established to operate domestic satellite telecommunication and broadcasting services.
In practice Aussat's charter restricted it from acting as a competitor to Telecom, including a prohibition on interconnecting public switched traffic with Telecom's network. Aussat's viability was undermined through restrictions on raising capital, of critical importance given tepid government support and increasing costs. It wasn't until 1985 that Australia's first geostationary communications satellite was operational; by late 1990 it had debts of about $400 million.
The Australian Telecommunications Commission was restructured as the Australian Telecommunications Corporation, trading as Telecom Australia, in 1989. That year saw the last domestic telegram handled by Telecom, with responsibility for telegram operations handed over to Australia Post.
Proposals for a merger of Aussat and OTC (thereby permitting national delivery of telecommunication services in competition with Telecom) were rejected in favor of disposal of the satellite operator to a non-government entity that would be allowed to compete with Telecom.
Immediately following the decision that Optus Communications - a private sector entity owned by a consortium that included BellSouth - would be given Australia's second general carrier licence purchased the Satellite assets with many of the Non Satellite Assets remaining with the Government as part of Telstra.
Cable & Wireless, privatised after several decades of UK government ownership, took a controlling stake in Optus in 1998 (under the banner Cable & Wireless Optus) before control passed to SingTel in 2001.

Telecommunications in Australia

Early

A memorial at Narrandera, New South Wales to the "J" trunk route linking the Australian cities and towns on the east coast
Following federation, the colonial networks (staff, switches, wires, handsets, buildings etc.) were transferred to the Commonwealth and became the responsibility of the first Postmaster-General (PMG), a federal Minister overseeing the Postmaster-General's Department that managed all domestic telephone, telegraph and postal services. With 16,000 staff (and assets of over £6 million) it accounted for 90% of the new federal bureaucracy. That figure climbed to over 120,000 staff (around 50% of the federal bureaucracy) by the late sixties.
Public phones were available in a handful of post offices and otherwise restricted to major businesses, government agencies, institutions and wealthier residences. Eight million telegrams were sent that year over 43,000 miles of line.
There were around 33,000 phones across Australia, with 7,502 telephone subscribers in inner Sydney and 4,800 in the Melbourne central business district. A trunk line between Melbourne (headquarters of the PMG Department) and Sydney was established in 1907, with extension to Adelaide in 1914, Brisbane in 1923, Perth in 1930 and Hobart in 1935.
An old bakelite ash tray showing an example of a single digit phone number used in the early days of telecommunication.
Overseas cable links to Australia remained in private hands, reflecting the realities of imperial politics, demands on the new government's resources, and perceptions of its responsibilities. The PMG department became responsible for some international shortwave services - particularly from the 1920s - and for a new Coastal Radio Service in 1911, with the first of a network of stations operational in February 1912. Australia and New Zealand had ratified the 1906 Berlin Radio-telegraph Convention in 1907.
During the 1930s the PMG became responsible for the Australian Broadcasting Commission (ABC).

A Brief History of Telecommunications


A Brief History of Telecommunications

BrianB (1184 days ago)
‘Telecommunication’ is a term coming from Greek and meaning ‘communication at distance’ through signals of varied nature coming from a transmitter to a receiver. In order to achieve effective communication, the choice of a proper mean of transport for the signal has played (and still plays) a fundamental role.
tin can telephoneIn ancient times, the most common way of producing a signal would be through light (fires) and sound (drums and horns). However, those kinds communications were insecure and certainly left room to improvement as they did not permit message encryption nor a fast transmission of information on a large scale.
The true ‘jump’ in terms of quality came with the advent of electricity. Electromagnetic energy, in fact, is able to transport information in an extremely fast way (ideally to the speed of light), in a way that previously had no equals in terms of costs reliability. Therefore, we may say that the starting point of all modern telecommunications was the invention of the electric cell by Alessandro Volta (1800).

The Future of A.M.

The Future of A.M.

Poor old AM sure took its hits, Tom. But there's a lot afoot these days, First off, the consolidation of ownership has in its way changed many stations from local issue-orientation to regional broadcasters. And, the way telecommunications has become a commodity, we find those regional owners having a set of studios in which programs for a dozen or more stations are generated, I've just been in Tampa, to find a studio center of Clear Channel, one of the largest owners, running nine studios with programs for a dozen stations in and around Tampa and Florida's West Coast, for example.
More recently, on an auto trip from here to Dallas via Atlanta, I noticed several AM's which individually could not cover the Atlanta metroplex, but which carried the same program all day. One pair was even on adjacent channels, 1060 and 1070, so it took but a flick of the dial to continue to hear their program when driving across the entire city, as I did.
And, there's the newly emergent matter of IBOC- In-Band On-Channel digital AM stereo transmission. As with most technologies, there's a American way that's incompatible with the European "world standard" way, but if you heard the results of either, you'd be amazed. There's a website somewhere that I stumbled on that plays audio from both ways, and the digital result is nothing short of amazing! One of the demos is a movement from a full orchestra classical piece, played on a shortwave broadcast station, The analog sample is full of all the noises, fades and distortions of shortwave radio, while the digital rendition is crystal clear the whole time.
Will that save AM? Will satellite-delivered radio kill both AM and FM? Who knows? All I can say is I'm not scrapping my old Hallicrafters just yet. If nothing else, it may become a museum piece! If you'd like to see more about me, see my (out of date) personal website: http://members.fortunecity.com/donkimberlin/ (external link)

"My interest in telecommunications spans the earliest forms of electric telegraphy in 16th century Spain up to the early 20th century.

Radio Telephone

Radio Telephone

  • "The system operators were companies licensed to provide mobile telephone carriers, much like the cellular carriers of today. In most major cities, serviced was provided by the local Bell Telephone Company, and a few private companies, sometimes called radio common carriers (or RCCs). Customers had the choice of selecting the carrier that provided the service they needed. However, the service was expensive, and the quality of the connection was poor."

  • From The Cellular Telephone Installation Handbook, by Michael Losse, Quantam Publishing, 1988.

Motorola TLD-1100 "MJ" IMTS Telephone, 1963. The text reads:

CONFORMS TO ALL IMPROVED MOBILE TELEPHONE SYSTEM REQUIREMENTS INCLUDING: Full 11-Channel Capacity for Unlimited Roaming; Automatic Channel Hunting; Home, Roaming or Manual Operation

PROVIDES BONUS PERFORMANCE FROM ALL SOLID STATE, BUILT IN MOBILE SUPERVISORY UNIT: Totally Silent Operation; Easy Installation of The One-Package Design; Minimum Maintenance from The Solid State Circuitry

Used in Bell territories. Equipment below used in some non-Bell territories.
GTE DTD/DTO Mobile Telephone. Illustration shows the dial control unit, manual control unit, a power/control cable, and the transceiver itself, along with the antenna.