Data transmission system between telephone subscriber location and telephone exchange location during idle telephone condition
AssigneeThe Post Office
InventorsLeonard William Kingswell, Oliver Charles Matthews
Life of this patent
Estimating the term…
Abstract
An electrical data transmission system employs a telephone line to transmit data from a subscriber data equipment to a telephone exchange data equipment when the telephone line is idle. A first idle line sensing means is associated with the subscriber equipment and is operable to connect the line to the subscriber equipment when the line is idle and to disconnect the line from the subscriber equipment when the line is busy. A second idle line sensing means is associated with the exchange data equipment and is operable to connect the line to the exchange equipment when the line is idle and to disconnect the line from the exchange equipment when the line is busy.
Claims15
A data transmission system for transmitting information over a telephone line comprising a line for connecting the telephone to a telephone exchange, first idle line sensing means associated with the subscriber end of the line and operable to connect the line to subscriber data equipment when the line is sensed to be in an idle condition and to disconnect the line from subscriber data equipment when the line is sensed to be in a busy condition, second idle line sensing means associated with the exchange end of the line and operable to connect the line to exchange data equipment when the line is sensed to be in an idle condition, and to disconnect the line from the exchange data equipment when the line is sensed to be in a busy condition, the arrangement being such that a data transmission circuit is established between the exchange data equipment and the subscriber data equipment when the line is in the idle condition.
Dependencies are inferred from the claim text.