Line testing method and apparatus therefor

Abstract

To facilitate the use of relatively high frequency data transmission services over a wireline communication resource originally deployed to support low frequency voice band services, an assessment of the wireline communication resource ( - ) is based on attenuation of high frequency test signals, of known original level, that are generated ( ) injected into the wireline communication resource from a test point ( ). A detector ( ) at a potential point of service, e.g. at a customers' premises ( ), detects an attenuated level of the test signals and generates a control signal ( ), such as a drive current, indicative of the attenuation caused by the wireline communication resource ( - ). The control signal ( ) is then indirectly communicated back to the test point ( ) in a coded form, and preferably within a voice band transmission. The coded form may be realized as modulation of a power supply provided to the customers' premises by the wireline communication resource, or could be achieved by up-link frequency mixing. In its most basic form, the control signal causes fluctuation on a visual level indicator at the customers' premises and therefore relies on a customer providing a verbal or toned response to the test point as to the level of the visual indicator. Effective attenuation at high frequencies can then be assessed based upon analysis of information coded into the voice band signal and its direct relationship with the original level of the injected high frequency signals.