Edumantra has the best explained Full Form of STD. Take advantage of freely available STD full form at our website. Remain full of knowledge of Meaning of STD. We would like to tell that the full form of STD is Subscribe Toll Dialing or Subscriber Trunk Dialing.
STD — Subscriber Toll Dialing (or) Subscriber Murk Dialing
STD Full-Form refers to Subscribe Toll Dialing (or) Subscriber Trunk Dialing. STD is a telephone system that enables subscribers to make trunk calls without any assistance from operators.
This term was first used when the possibility of making long-distance calls by dialling directly presented itself. Currently, it is utilized rarely due to the introduction of mobile phones, which can be used for directly calling any destination. The Full-Form of STD, which is subscriber toll dialling, is utilized in Southeast Asia, Australia, the UK, India, and the Republic of Ireland.
The DDD or Direct Distance Dialing is the corresponding term of STD used in the NANP or North American Numbering Plan. The NANP is used in Canada and the US. In the year 1963, the subscribers of STD in London were able to call people in Paris directly by using IDD or International Direct Dialing. This resulted in the extension of STD. The difference between the toll and trunk calls became non-existent with the introduction of the subscriber dialling for the long-distance calls in the UK.
However, this term is still commonly used in nations like India for describing any call (national) that are made outside of a local place. A subscriber is a person who rents or subscribes a telephone line. A trunk call, on the other hand, is a call which is made using a trunk line. A trunk line is a telephone line that connects two persons that are present at a long distance from each other. Currently, it has become possible to directly make a long-distance call; hence this term is not used much.
History of STD
In the earlier days of the introduction of the telephone systems, the subscribers used to call a telephone exchange, asked an operator to connect the subscriber’s call to another one who is on the same exchange. During that time, making calls to the subscribers of other exchange systems was not possible. After some years, people were able to call others of the same exchange directly. However, calling someone of another exchange involves the help of an operator, who helped in establishing the connection. People started using the term ‘subscriber trunk dialling’ when subscribers residing in one area obtained the facility of dialling non-local subscribers.
The facility of STD started in the year 1958 when the Queen publicly announced the STD’s usage by dialling from Bristol to Edinburg. The system finally covered the entire nation in the year 1979. However, the majority of the UK was covered well before that year. The facility given by the system needed a new code, which was allocated to the UK’s every area. In the present times, the area codes in the UK are still referred to as the STD codes.
STD Numbering Plan
When the STD was introduced, each city having a director system was given a code of three digits. In this code, the second digit referred to the city name’s first letter. The only exception to this rule was London. It had 01 as its code. These codes were changed after some time. Currently, the codes of London, Edinburg, Liverpool, Birmingham, Glasgow, and Manchester are 020, 031, 051, 021, 041 and 161 respectively.