Harris Corporation

Ronald S Squires

Richard D Roberts

George Rodney Nelson, Jr

Edward J Zoiss

Linda L Hathorn

Glen Holt Humphrey

James D Coleman

The performance of digital subscriber loops is tested through transmission, reception and analysis of a multi-tone power ratio (MTPR) waveform, containing plural discrete tones having equal spectral spacings and notches periodically distributed among the tones. The noise floor at a missing sub-carrier spectral location is integrated and compared to signal power of an adjacent sub-carrier within the test vector waveform. From these two values, MTPR is determined for various carrier locations, so that maximum theoretical loop payload can be calculated. To generated a figure of merit (FOM) under test, a data modem is placed at each end of the loop. The FOM obtained from MTPR analysis is channel based, not equipment based, and is independent of receiver implementation. Before placing a new customer in service, the MTPR FOMs for a number of loops are compared to bit rate information in a database, which correlates MTPR with a bit rate for a specific modem. Given the terminal equipment, MTPR FOMs, and the customer's data rate, one or more cable pairs that satisfy or exceed the FOM within an available cable bundle may be selected.

Testing of digital subscriber loops using multi-tone power ratio (MTPR) waveform

A wireless butt set for testing a telephone line includes a base station that is connectable to tip and ring leads of a line under test and is configured to be operated by a wireless telephone handset. The handset is detachably nestable with the base station to form a hand-held integrated butt set assembly. This configuration allows a craftsperson to directly or remotely control the test set using controls of the wireless telephone handset. The internal circuitry of the base station is placed in a high impedance line-monitoring mode without going off-hook, in response to one 'click' of a talk switch of the handset, and goes off-hook in response to a 'double-click' of the talk switch the handset.

Wireless butt set

Testing of digital subscriber loops using multi-tone power ratio (MTPR)

Growing community of inventors

Agoura Hills, CA, United States of America

Ronald S Squires