Question 17/XV - Characteristics of coding (e.g. PCM, ADPCM) and digital
multiplexing equipment for use in local networks including
narrow-band and broadband ISDN access (New Question)
Considering

(1) that many administrations are already deploying broadband/high bit
rate systems in their local networks to provide, for example, business
communications services, audiovisual services, etc.;

(2) that such applications in the local network are highly cost
sensitive;

(3) that broadband ISDN is being studied by Study Group XVIII;

(4) that transmission equipment already recommended is, in general,
optimized for use in main networks and the special requirements of the
local network may not have been taken into account;

(5) that systems in the local network are generally of short range;

(6) the possibilities for broadband transmission offered by optical
fibres,

What characteristics should be recommended for coding and digital
multiplexing equipment for use in local networks?

Points for study

1.Applications and performance requirements.

2.The types of equipment required, e.g. multiplexing 64 kbit/s access,
low bit rate encoding, broadband access, etc.

3.Type of service to be carried, e.g:

- PSTN circuits
- analogue private circuits
- analogue data circuits
- digital private circuits
- digital data circuits
- broadband circuits.

4. Characteristics of electrical interfaces.

5. Bit rates/signals to be accommodated at transmission interfaces.

6. Cost reduction measures.

7. Size and modularity.

8. Time slot access flexibility/time slot interchange.

9. Programmable/remote control facilities.

10. Environmental conditions if some other studies appear necessary.

11. Maintenance aspects.

12.Application of Operations, Administration and Maintenance interfaces
as given in Recommendation G.771 - any unique features required.

13. Network constraints and considerations.

Notes

1. Any equipment recommended should be able to meet, or be capable of
evolving to meet, any relevant broadband requirements that may be
recommended by Study Group XVIII.

2. Operations, Administration and Maintenance interfaces on transmission
equipment are studied under Question 9/XV.

3. The study of this Question should be coordinated with the study of
Questions 16/XV and 18/XV.

4. Account may need to be taken of the studies of Questions 1/XV, 2/XV,
3/XV, 4/XV, 19/XV and 20/XV.

5. Account should be taken of the studies of ISDN (including any access
bit rates), the new synchronous hierarchy and general network issues
carried out by Study Group XVIII.