Subscriber trunk dialling
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Subscriber trunk dialling (STD, also known as subscriber toll dialling) is a term for a telephone system allowing subscribers to dial trunk calls without operator assistance.
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[edit] Terminology
As well as the UK, the term "subscriber trunk dialling" is used in other countries such as the Republic of Ireland, Australia and India. The corresponding term in the USA and Canada is direct distance dialling.
The term was extended when, on 8 March 1963, subscribers in London were able to directly dial Paris using international subscriber trunk dialling.
[edit] Explanation
The introduction in the UK of subscriber dialling of long distance calls removed the distinction that had existed between Trunk and Toll calls. This term however, is still widely prevalent in India to describe any national call made other than one's local unit. A "subscriber" is someone who subscribes to, i.e. rents, a telephone line and a "trunk call" is one made over a trunk line, i.e. a telephone line connecting two exchanges a long distance apart. Now that all calls may be dialled direct, the term has fallen into disuse.
[edit] History
In the UK, STD started on 5 December 1958 when the Queen, who was in Bristol, dialled a phone call to Edinburgh – the furthest distance a call could be directly dialled.[1] The STD system was completed in 1979,[2] though most of the country was covered well before then. The system required that each area have its own STD code which could be dialled by subscribers, and although they are now officially called area codes, it is still common to see and hear the old term in everyday use.
[edit] See also
- Trunk prefix
- Telephone numbers in the United Kingdom
- Telephone numbers in India
- List of country calling codes
[edit] References
- ^ "Events in Telecommunications History: 1958, 'BT's history', btplc.com/". 2008-06-18. http://www.btplc.com/Thegroup/BTsHistory/1912to1968/1958.htm. Retrieved 2008-08-12.
- ^ "Events in Telecommunications History: 1979, 'BT's history', btplc.com/". 2008-06-18. http://www.btplc.com/Thegroup/BTsHistory/1969to1980/1979.htm. Retrieved 2008-08-12.
[edit] External links
- STD codes in India
- The archives of BT including archives of its predecessor organizations: A good source of information relating to the history of the telephone system in the UK.
- Archive news article from the BBC on the introduction of Subscriber Trunk Dialing.
- BBC video of first call taking place
