Upgrading strategies for B-ISDN subscriber loops

Upgrading strategies for broadband-ISDN subscriber loops are investigated. A five-step process for optimizing phase-by-phase system upgrading from existing narrowband ISDN to future superbroadband ISDN is developed. The process is designed to be as simple as possible and to include as many environmental conditions, such as network models, subscriber capacities and associated penetrations, and cost trends for system components, as possible. A typical example is given to show the efficacy of the optimization process. It is shown that more general aspects of system upgrading can be extrapolated from the representative examples given