Objectives
After completing this course, the student will be able to:
■ Sketch a troubleshooting plan to tackle specific VoLTE failures
■ Demonstrate proficiency in VoLTE troubleshooting tasks
■ Analyze VoLTE-related KPIs and identify issues in the network
■ Use UE and network traces to perform root-cause analysis of specific failures
■ Analyze VoLTE Setup, Drops, and voice quality performance issues
■ Explain and analyze RTP and related traffic plane logs
Outline
1. VoLTE Troubleshooting Overview
1.1 Components of VoLTE calls
1.2 Failure categories
1.3 RAN KPIs for VoLTE
Exercise: Knowledge of tools/probes/protocol
2. VoLTE Call Setup Analysis
2.1 Accessibility KPIs
2.2 Default and Dedicated bearer setup for VoLTE
2.3 VoLTE call setup failure signatures
2.4 Review call setup statistics
Exercise: Case Study: VoLTE Call Setup failure
3. VoLTE Call Drop Analysis
3.1 VoLTE Call Drop KPIs
3.2 Use of TTI Bundling
3.3 VoLTE call drop failure signatures
3.4 Review call drop statistics
Exercise: Case Study: VoLTE Drops
4. VoLTE Call Quality Analysis
4.1 Measuring quality: MOS, ACQ KPIs
4.2 RTCP Reports from UEs
4.3 Impact of high latency, jitter and packet loss
4.4 Components of the latency budget
4.5 Understanding audio gaps
4.6 Review gap count and duration statistics
4.7 Analyze gaps in a specific call
Exercise: Case Study: RTP Flow and Audio Gaps
5. VoLTE Capacity Analysis
5.1 VoLTE Capacity KPIs
5.2 PDCCH capacity and Semi-persistent Scheduling
Exercise: Case Study: Connected User and PDCCH Analysis