tailieunhanh - HDSL2 TECHNICAL BRIEF

HDSL technology has proven to be highly reliable and has played a major role in easing many time and cost issues associated with T1 line provisioning and installation. For example, an HDSL T1 solution can reach 12,000 feet. For the same distance, the old repeatered T1 method would require labor-intensive installation of a repeater module every 3,000 feet. | HDSL2 Technical Brief The Single Loop Advantage Over SDSL Overview Demand for high-speed data services and Internet access is on a dramatic upswing in the business world. As a result telecommunications service providers have widely adopted T1 lines as the preferred vehicle to provide the speed and bandwidth to deliver these vital services. In 1997 there were approximately million T1s installed in the United States. Conservative estimates show T1 deployment growing at a healthy 30 to 40 percent a year. High bit-rate digital subscriber line HDSL technology is the dominant choice among carriers for delivering T1s. In fact more than 50 percent of the T1s being installed today on copper employ HDSL. A new standard has emerged in delivering T1s over unbundled copper called HDSL2. Ill HDSL2 Technical Brief The HDSL Standby HDSL technology has proven to be highly reliable and has played a major role in easing many time and cost issues associated with T1 line provisioning and installation. For example an HDSL T1 solution can reach 12 000 feet. For the same distance the old repeatered T1 method would require labor-intensive installation of a repeater module every 3 000 feet. A Single Solution In the telecom world carriers are constantly under pressure to deliver services more cost effectively while reducing installation intervals. Another pressure point is the carriers need to conserve their preciously limited but highly coveted copper resources. To meet these requirements of change the industry has begun a migration from two copper pair solutions such as HDSL to single-pair solutions. The theory is that these single-pair offerings will provide the same data rates as two-pair technologies while using half the copper resources. Equipment vendors are currently working together in the American National Standards Institute ANSI subcommittee to develop HDSL2 a next-generation single-pair version of HDSL. HDSL2 provides full duplex Mbps transmission over a single