Question 24/XV - Speech packetization systems
(Continuation of Question 32/XVIII 1985-88)

Considering

(1) that packet switched services are widely provided through the
nation-wide and world-wide telecommunication networks as well as small-
scale local area networks;

(2) that it may be desirable to handle not only data but also speech in
packet switched networks to improve the serviceability of the networks;

(3) that studies on speech packetization are being widely performed and
that the performance of packetized voice is being analyzed to some
extent,

1. What coding algorithm(s) and bit rate should be recommended for use
in speech packetization systems?

2. What packetization techniques should be recommended?

3. What protocol characteristics at Layers 2 and 3 should be recommended
for packetized voice? Are these protocol characteristics also suitable
for data communications?

4. What testing conditions and testing methods should be recommended to
evaluate the performance of the recommended speech packetized system?

5. What method for sending signalling through speech packetization
systems should be recommended?

6. What methods for sending digital data, 64 kbit/s clear channel, data
modem and facsimile signals through speech packetization systems should
be recommended?

7. What methods of signal priority allocation, overload mitigation,
speech traffic control and data flow control should be recommended?

Points for study

1.Applications and performance requirements that should be considered.

2.Network considerations and restraints, e.g. hybrid combinations of
packet and circuit switched speech signals.

3.Packetizing techniques, e.g.:

- packet length
- synchronization (time stamping)
- speech detection
- packet assembling
- echo control.

4.Implications for network equipment, e.g. packet cross-connect and
packet switching systems.

5.The relationship to ATM and broadband ISDN.

Notes

1. Account should be taken of the work of Study Group XII on
transmission plan issues, and speech performance of digital systems.

2. Account should be taken of the work of Study Group XVIII on the ISDN
and general network issues.

3. Account should be taken of the studies of DCME carried out under
Question 10/XV.

ANNEX 1

(to Question 24/XV)

Algorithm and protocol for speech packetization

3.

Appendix 1

(to Annex 1 of Question 24/XV)