Combined handset and POTS filter

Abstract

The present invention is generally directed to a telephone handset for testing the transmission quality of a local loop. In accordance with one aspect of the invention, the telephone handset includes a connector configured to connect to the local loop at, for example, a junction box. The invention also includes a low-pass filter circuit electrically interposed between the connector and operational circuitry of the telephone handset. In operation, the low-pass filter is designed to pass (substantially undisturbed) electrical signals within the POTS frequency band from the connector to the operational circuitry. In the same way, the low-pass filter is designed to substantially block the passage of electrical signals above the POTS frequency range. In this way, the low-pass filter blocks the introduction of high frequency signals, which may otherwise generate intermodulation products within the audible range, from reaching the operational circuitry of the testing handset. In accordance with another feature of one embodiment of the invention, a device is provided for detecting the presence of xDSL signals on a local loop. In accordance with this embodiment, at least one band-pass or high-pass filter is added in parallel with the low-pass filter. The output of the at least one band-pass or high-pass filter is then analyzed to determine whether an xDSL signal is present within that frequency band (defined by the at least one band-pass or high-pass filter).

Dependencies are inferred from the claim text.