Agere Systems Inc.

Lixi Wu

Jason A Trachewsky

Steven E Strauss

John T Holloway

Signature apparatus and techniques that make home networking devices, e.g., in-Home Phoneline Network (herein referred to as &ldquo;HPN&rdquo;) devices, isolation filters, network interface devices, etc., detectable by commercially available metallic loop termination (MLT) test equipment. The invention also provides a method of testing a telephone line for the existence of a signature circuit identifying a home network. The home network signature circuit includes a series combination of a voltage breakdown device (e.g., Zener diodes) and an impedance (e.g., 200K ohm resistor). In operation, the home network signature circuit shunts the tested subscriber line loop with a voltage-dependent impedance in the presence of an appropriate test voltage exceeding 80 volts. Different high voltage thresholds of the voltage breakdown portion and/or different resistance values of the shunt impedance can be implemented in the home network signature device to produce uniquely detectable signatures. In this way, it is possible to remotely differentiate between various types of home network devices if the various types of home network devices include known voltage thresholds and/or shunt impedances. Loop qualification for services such as VDSL could include an automated remote scan from a central office for home network signature devices being served by telephone lines, e.g., existing in the same binder. To sense each of the parallel connected home network signature devices, the test equipment may preferably be made sensitive to the threshold voltage, not to the shunt impedance. The home network signature circuit may simply reside between the tip and ring on an HPN adapter. The home network signature circuit is preferably functional whether or not the network device is powered up. The home network signature circuit, in response to the activation energy signal exceeding a predetermined threshold above 80 volts, will drive an appropriate current back onto the telephone line.

Growing community of inventors

San Jose, CA, United States of America

Lixi Wu