Question 26/XV - Harmonization and update of the texts in
Recommendations in Volume III of the Blue Book in so far as they relate
to transmission equipment, metallic cables and systems
(Continuation of Question 14/XV 1985-88)

Considering

(1) that there may be inaccuracies in, and inconsistencies between, the
texts of Recommendations in Volume III of the Blue Book;

(2) that it may desirable to update the text of established
Recommendations in Volume III of the Blue Book relating to transmission
equipment, metallic cables and systems to take account of important
developments,

1. What amendments are required to improve the accuracy and
harmonization of the texts of all Recommendations in Volume III of the
Blue Book?

2. What amendments are required to update Recommendations in Volume III
of the Blue Book insofar as they relate to:

2.1analogue transmission of sound programme and television signals?
2.2 compandors?
2.3 digital multiplex, coding, transcoding and transition equipment?
2.4 metallic cables?
2.5 digital line systems on metallic cables?
2.6 coding and transcoding algorithms?

3. What Recommendations in Volume III of the Blue Book do not need to be
reproduced in the next coloured Book?

ANNEX 1

(to Question 26/XV)

List of remaining items for further studies
on Recommendation G.722

1.Section 2: need for separate specifications of the transmission
characteristics of the send and receive parts - definition of a
"standard transmitter" and a "standard receiver"

2.Point 2.2: the measurement method of the overload point

3.Point 2.4.3: the eventual increase of the group delay specification
from 4 to 8 ms in relation with the oversampling techniques for the
realization of A/D and D/A converters

4.Point 2.4.6: the signaltototal distortion for the whole codec

5.Points 2.5.5 and 2.5.6: need for a specification of the measurement
method of the signaltototal distortion ratio as a function of level and
as a function of frequency

6.Point 2.5.8: intermodulation

7.Point 2.6: the eventual specification of the group delay difference
between a G.711 implementation and a G.722 implementation in the same
terminal

8.Appendix 1 to G.722, Point 1.8: the derivation of a 64 kbit/s PCM
signal solely from the lower subband of the 64 kbit/s, 7 kHz signal

9. Appendix 2 to G.722: the test of the QMF