provision the service. This attribute eliminates the need to identify, modify, and verify a controlled environment, with power, secured access, and other factors needed to support repeater equipment. It also reduces the time, cost, and effort of isolating faults and taking corrective action when a failure does occur. Studies by some service providers have indicated that trouble shooting and replacing defective repeater equipment often costs significantly more than the cost of the equipment itself. These attributes translate into increased network up time and reduced engineering time; making possible T1 provisioning in a matter of days, as opposed to weeks. Faster service provisioning and greater up time leads to increased customer satisfaction and increased service revenues. To provision a 12 kft (3.6 km) local loop with traditional T1 transmission equipment requires two transceivers and two repeaters. To provision the same loop with HDSL, requires only two HDSL transceivers, one at each end of a line. S-HDSL/SDSL Single-pair or Symmetric High-bit-rate Digital Subscriber Line (S-HDSL/SDSL) operate on a single copper pair as opposed to the traditional two pair HDSL described above. S-HDSL/SDSL allows easy implementation of applications that require symmetric data rates on a single local loop while maintaining the existing POTS on the same loop. Because only one pair is needed in this arrangement, the capacity of the entire local loop infrastructure is greatly magnified. With this capability, local providers can extract the maximum value from their existing plant, or deploy new capacities both more quickly and at a lower capital expenditure. This allows for rapid and cost effective deployment of intermediate data rate services. Potential uses for this technology include fractional T1 with a particular advantage in 768 kbps systems, Home Office, LAN Access, Distance Learning, Internet Access, and Campus or Large Facility LAN to LAN connect...
