Question 19/XV - Characteristics of digital multiplexing equipment for
the synchronous hierarchy

Considering

(1) that Recommendation G.707 gives the hierarchical bit rates for the
synchronous hierarchy;

(2) that Recommendation G.708 gives a Network Node Interface for a
synchronous hierarchy;

(3) that Recommendation G.709 gives the basic method to be used for
multiplexing signals at the hierarchical bit rates given in
Recommendation G.707;

(4) that there will be a need in the synchronous digital hierarchy for
multiplexing equipment operating at the hierarchical bit rates given in
Recommendation G.707, conforming to the basic multiplexing method given
in Recommendation G.709 and conforming to the interface specification
given in Recommendation G.708;

(5) that existing Recommendations in the G.700-Series give
characteristics for multiplexing equipment used for multiplexing signals
into hierarchical bit rates given in Recommendation G.702,

What should be recommended for the characteristics of multiplexing
(including add/drop multiplexing) equipment for the synchronous
hierarchy?

Points for study

1.The signals or groups of signals that should be accommodated at the
tributary side of the multiplexing equipment.

2.Characteristics of transmission electrical interfaces.

3.Bit rates that should be accommodated at the transmission interfaces
on the multiplexed side.

4.Size and modularity.

5.Synchronization interfaces.

6.Overhead processing.

7.Pointer characteristics.

8. Environmental conditions, if some other studies appear necessary.

9.Maintenance aspects.

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

11.Information and control signals that may need to be passed between
multiplexing equipment and this type and a Telecommunications Management
Network (TMN).

Notes

1. Operations, Administration and Maintenance interfaces on transmission
equipment is carried out under Question 9/XV.

2. Account should be taken of the studies of the synchronous hierarchy
being undertaken by Study Group XVIII.

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