Question 6/XVII - Characteristics of a device used to interface a DTE to
digital channels other than ISDN
(New Question)

Considering

(a) that there is an increasing need for leased circuits with data
signalling rates of 64 kbit/s and multiples thereof;

(b) that most applications at these data signalling rates do not require
more interchange circuits than the data and timing circuits;
(c) that PCM transmission paths capable of conveying 64 kbit/s or
multiples thereof are internationally available;

(d) that Recommendations V.36 and V.37 already specify DCEs for data
signalling rates of up to 144 kbit/s using analogue transmission paths
according to Recommendations of the H-Series;

(e) that ISO 4902 and ISO 4903 specify DCE/DTE interface connectors
which are, by their nature, not restricted to data signalling rates of
64 kbit/s or 144 kbit/s;

(f) that Recommendations V.36 and V.37 already address an optional PCM
interface;

a study should be made of the characteristics of a device interfacing a
DTE to existing PCM transmission paths.

The study shall comprise:

-control of remote loops according to Recommendation V.54,

-rate adaption techniques for 48 kbit/s and 56 kbit/s,

-definition of scramblers,

-definition and allocation of framing for G-Series interfaces,

-definition of characteristics of interface connectors for G-Series
interfaces in close cooperation with ISO/IEC.