Using two pairs of copper wires to provide T1 transport delivery, HDSL4 maintains spectral compatibility beyond the carrier service area (CSA) range as well as on repeatered loop applications. Service providers can realize numerous benefits by deploying this latest advancement in symmetric DSL services. For instance, the technology offers extended reach and spectral compatibility with ADSL. In order to make optimal DSL technology deployment choices, though, service providers need to carefully analyze the application before selecting technologies and the associated equipment | HDSL4 Reliable _onger Reach Spectrally Compliant T1 Transport Abstract Using two pairs of copper wires to provide T1 transport delivery HDSL4 maintains spectral compatibility beyond the carrier service area CSA range as well as on repeatered loop applications. Service providers can realize numerous benefits by deploying this latest advancement in symmetric DSL services. For instance the technology offers extended reach and spectral compatibility with ADSL. In order to make optimal DSL technology deployment choices though service providers need to carefully analyze the application before selecting technologies and the associated equipment. HDSL4 is the latest advancement in symmetric digital subscriber line DSL solutions for T1 delivery. In February 2002 the committee approved the Issue 2 HDSL2 standard which includes HDSL4 as a 4-wire symmetric T1 transport solution. HDSL4 offers the same robust performance as HDSL and HDSL2 providing a maximum bit-error-rate BER of 10e-7 with 5 dB of margin over a 1 worst-case mixed crosstalk environment. What makes HDSL4 unique is that it is a spectrally compliant T1 transport solution that extends the repeaterless reach to 16kft 24 AWG and the repeatered reach to up to 46kft 24 AWG . When used with repeaters HDSL4 is the only T1 transport technology that meets spectral compatibility requirements with ADSL per the ANSI spectrum management standard. What are the Benefits of HDSL4 HDSL4 offers considerable cost savings and better utilization of local loop bandwidth. The advantages of using HDSL4 products include spectral compatibility with ADSL extended reach using fewer repeaters and cost savings in installation and power consumption. Spectral Compatibility with ADSL With the variety of xDSL technologies being deployed in the same copper binders spectral compatibility is becoming extremely important to limit crosstalk noise interference between the pairs and to achieve performance targets. In 2001 .
