subscriber trunk dialling
noun1
Communications, Electrical engineering, Engineering, Natural sciences, Physical sciences, Telecommunications, Telephony UK A system of automatic connection of trunk calls through dialling a phone number without operator assistance.
- This NER microwave radio telephone link will bring subscriber trunk dialling facilities to no fewer than 3,000 railway telephones at York, Newcastle, Darlington, Middlesbrough and Leeds and points as far north as Berwick-upon-Tweed.1964 August, “The NER's microwave radio-telephone begins work”, in Modern Railways, page 130: