| 摘要 |
A method for determining the length of a telephone line from an exchange to a subscriber. The method is based on the availability in the exchange of so-called line circuits (LC1-LC4), each having a given amplification factor G for the signal transmitted from a given subscriber through the line, this factor being stored and made available to the microprocessor (MP) of the line circuit card (LK), and also that the attenuation for each unit of line length D between the exchange and the subscriber is known. Since these magnitudes are known, the line length L is calculated in the microprocessor (MP) from the equation L = k.G/D, where k is a constant which is calculated for a given determined length, amplification factor and attenuation/length unit. |
