Question 12/XV - Characteristics and test methods for multimode optical
fibre cables (Continuation of Question 21/XV 1985-88)

Considering

(1) that existing Recommendation G.651 which gives characteristics and
test methods for 50/125 5 m graded index optical fibre cables is based
on the technology used with source wavelengths around 850 nm and 1300
nm;

(2) that requirements for Reference Test Methods and Alternative Test
Methods are also contained in Recommendation G.651;

(3) that particular applications, e.g. local networks, may require
appropriate choice of different fibre types and dimensions;

(4) that the requirements of those private networks which include
elements of public networks may need to be taken into account;

(5) that Recommendation G.651 has some items that are still open for
further study,

1. How should Recommendation G.651 be amended and completed?

2. What new Recommendations should be prepared for other types of multi-
mode optical fibres?

3. What additional Reference Test Methods and Alternative Test Methods
need to be established?

4. Where should definitions and test methods be located?

Points for study

1.The interrelationship between fibre parameters and transmission
characteristics.

2.The interrelationship between the transmission properties of cable
factory lengths and elementary cable sections.

3.The geometrical, optical and transmission characteristics of different
multimode optical fibres.

4.Possible operation

- at around 1550 nm
- with bidirectional transmission
- with wavelength division multiplexing.

5.Mechanical aspects of fibres and splices.

6. Reliability in various environmental conditions.

7. The extent to which the transmission characteristics are affected by:

- the make-up of cables
- methods of installation
- methods of jointing
- maintenance methods.

8.The need for additional Reference Test Methods.

9.The need for Additional Alternative Test Methods for factory and field
applications.

Notes

1. The study of points 5 and 7 should be coordinated with Study Group
VI.

2. The study of optical fibres for the local network should be
coordinated with the study of Question 14/XV.

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