1
Introduction
2 References
3 Definitions
4 Abbreviations and acronyms
5 Conventions
6 Echo control in telecommunication
networks
6.1 Echo control devices
6.2 General echo control considerations from a PSTN perspective
6.3 Additional echo control considerations from the perspective of
interconnected networks (e.g., private networks, the
Internet)
6.4 Application-related echo control considerations
6.5 Voiceband data modem constraints
7 Application rules and
operational constraints
7.1 Public network transmission planning
7.2 Delay considerations
7.3 Provisioning of the echo-path capacity and echo-path
characteristics
7.4 Echo canceller transmission planning for multiple
interconnected networks (e.g., public, private, Internet)
8 Network and service
evolutionary considerations
8.1 Bit transparency of echo cancellers
8.2 Non-linearities and time-variant effects in the echo path
8.3 Low bit-rate coding between tandem cancellers
8.4 Tandeming of echo
cancellers
8.5 Convergence speed
8.6 Acoustic echo control and environments
8.7 New circuit-switched service
8.8 Comfort noise
9 Special CME networking
considerations
9.1 Detailed interaction
9.2 Possible solutions
Appendix I – Echo-path dispersion time
I.1 Echo-path characteristics from measurements in North America
Appendix II – Multiple tail circuits
II.1 Multiple tails in a typical bridged telephone call
(North America)