Overview of ADSL test requirement towards conformance, performance and interoperability

The enormous installed base of copper in the access network with the right transmission techniques present a huge potential for delivering broadband services to bandwidth hungry customers. Various Digital Subscriber line technologies (xDSL) employ various transmission methods and efficiently utilize the last available bandwidth on existing copper wires. Asymmetric Digital Subscriber Line (ADSL) delivers up to 6 Mbps to the user. This transmission of 6 Mbps is achieved using sophisticated modulation and compression techniques in a spectrum up to 1.1 MHz, pushing the physical limit on the usable bandwidth in the copper. This technology co-exists with impairments, noise intrusions, bridge taps, and other non-spectrally compatible transmissions. This paper presents an overview of xDSL Technology (which includes ADSL), the test challenges facing ADSL technology, and outlines the three areas of ADSL tests needed to ensure product conformance and cross vendor interoperability.