Extending the bandwidth of the local loop

The authors consider the growth in demand for the delivery of new telecommunication services that require digital rather than analogue delivery. They highlight the problem that the provision of these services often requires the costly installation of new transmission media. For both service providers and end users, this can make the cost of serve provision prohibitive. High-speed digital subscriber line (HDSL) systems have been introduced in Europe, allowing transmission up to 2048 Mbit/s over conventional unscreened copper pairs. These systems combined with appropriate interfaces, will allow the timely and economic provision of a range of services that need up to a bit rate of 2048 Mbit/s. The authors consider the service applications of HDSL and develop a deployment strategy that allows the economic migration to fibre systems when service demands allow