Locating telephony loop impairments with frequency domain refectometry

Abstract

Usage of the Internet is growing at a rapid pace. This growing popularity has had an impact on the content available over the Internet. Today, many bandwidth hungry applications are available to end users: music files, streaming audi0jvideo, and video conferencing. To be of practical use, larger bandwidth applications require higher speed Internet connections to the consumer. One method of providing high speed Internet access to a home or small business is through twisted pair telephone cables.

Use of twisted pair to provide high speed Internet service is not without its problems. Many loop impairments exist that hinder high speed service, or prevent it altogether. Purposely placed impairments include loading coils and bridged taps. Unintentional impairments include wire splices and water in the cable casings. The locations of these impairments help the telephone companies (telco's) determine which lines have potential problems in delivering Internet access.

A new technique called frequency domain reflectometry (FDR) has been proposed to locate these loop impairments. This thesis focuses on proving the viability of using FDR to accurately detect loop impairments. A physical device was designed and constructed to use the FDR technique. The device was tested on various telephone loop configurations. The device was also compared with a commercially available product. The results of the testing indicate FDR is a viable alternative fqr locating loop impairments. It performs at least as well as commercially available products.