A vision of enhanced telephone services on an ISDN

The practical merits of providing basic-rate I-interfaces for POTS (plain ordinary telephone set) users is described. These include: no signal degradation due to transmission paths having digital links; two or more usable paths in individual, concurrent, and multimedia mode due to the independence of each channel; and usable call-control signals, independent of call state, due to outchannel signalling. It is also noted that, with ISDN (integrated services digital work), more functions for flexible telecommunications services should be allocated to the terminal side than in existing telephone systems. Many communications services become practical only when implemented as ISDN terminal functions. By making use of the above-mentioned merits, terminals can provide various enhanced services, such as broadcasting, locating, and answering