Simulation environments for the high-speed digital subscriber line (HDSL)

An overview is presented of the high-speed digital subscriber line (HDSL) simulation facilities and selected results from recent CAD environments for HDSL. The evolving integrated network services to the subscribers opens a variety of fundamental questions regarding their digital capabilities. Two significant aspects are covered: the organization of the HDSL CAD environment and the typical results comparing the performance of the limited carrier serving area loop population and with a corresponding performance of all the loops that are less than 12 kft in the typical American subscriber loop environment. The question of the design of the simulation environment which evolves, changes and matures as the applications and requirements change and grow is addressed. Dominant physical, spectral and time domain simulation results for HDSL at H1 and E1 rates with 2B1Q and carrierless amplitude and phase (CAP) modulation techniques for the CSA loops and all loops < 18 kft are presented