1 Scope
2 References
3 Definitions
3.1 Terms defined elsewhere
3.2 Terms defined in this Recommendation
4 Abbreviations and acronyms
5 Conventions
6 Brief introduction on Voice over LTE and assumptions
7 Hypothetical reference models
7.1 LTE-LTE communication on the same network
7.2 LTE-LTE communication between two interconnected networks
(includes roaming)
7.3 LTE-3G communication
7.4 LTE-PSTN communication
8 Aspects of quality of service for voice over LTE services
9 Relevant indicators and quality targets
10 Recommendations for QoS monitoring and troubleshooting
10.1 Recommended QoS monitoring points
10.2 Monitoring strategy
10.3 Available tools in ITU-T standards
Annex A – List of degradations encountered by end-users of VoLTE service and
their potential causes
A.1 QoS problem linked to call session performance
A.2 QoS problem linked to perceived speech quality
Bibliography