+353-1-416-8900REST OF WORLD
+44-20-3973-8888REST OF WORLD
1-917-300-0470EAST COAST U.S
1-800-526-8630U.S. (TOLL FREE)

Signals Ahead - Behind the VoLTE Curtain, Part One

  • ID: 3429767
  • Report
  • Region: Global
  • 67 Pages
  • Signals Research Group, LLC
1 of 4

FEATURED COMPANIES

KEY HIGHLIGHTS FROM THIS STUDY

We conducted an extensive benchmark study of AT&T’s VoLTE service offering in the Minneapolis-St. Paul area that we did in collaboration with Spirent Communications, who provided us with its test equipment and engineering support to collect much of the data. Based on our analysis of the data, we conclude that VoLTE is pretty much everything that we hoped it would be.

For starters, the call quality (MOS), based on the POLQA algorithm, greatly exceeded that of 3G CS voice and it was measurably higher than Skype Voice. With network loading, and in particular with background applications running on the mobile phone and transferring data with the network, the VoLTE results were considerably better than Skype (over Wi-Fi and LTE) – the former showed no impact while the latter frequently failed to deliver the voice packets. Relative to 3G CS voice, VoLTE’s other big advantage was the call setup time. A CSFB call took nearly twice as long to establish as a VoLTE call.

Lastly, VoLTE required substantially fewer network resources (DL/UL RBs, TTIs, PDCCH downlink scheduling grants (i.e., signaling traffic) etc.) than Skype and presumably other OTT voice applications, which in turn resulted in a longer estimated battery life – we separately measured both attributes. In large part these two advantages were achieved with several LTE features (RoHC, TTI bundling, and DTX/DRX) which are either not supported by an OTT application that isn’t assigned QCI=1 or which are supported less efficiently. Additional positive network and user experience implications are likely once SPS and short DRX are launched.

Continued improvements in LTE network coverage will give VoLTE an even greater advantage in the future, including an even longer battery life and fewer eSRVCC handovers to the 3G CS network.

SIGNALS AHEAD SUBSCRIPTION INFORMATION

This report is included as part of a subscription to Signals Ahead or it can be purchased separately.

Signals Ahead is a research-focused product that is published on a periodic basis. Its clientele include all facets of the wireless ecosystem, including some of the largest mobile operators, the top handset suppliers, the major infrastructure vendors, subsystem suppliers, semiconductor companies and financial institutions, including Wall Street, Private Equity and Venture Capitalists, spread across five continents.
Note: Product cover images may vary from those shown
2 of 4

FEATURED COMPANIES

1. Executive Summary

2. Key Observations and Conclusions

3. Voice Call Quality Analysis
3.1 Heavy to Moderate Network Loading – Stationary Testing
3.2 Moderately Heavy Network Loading, Including Background Application Downloads – Stationary Testing
3.3 Skype Voice over Wi-Fi – Light and Heavy Loading
3.4 MOS Drive Test – VoLTE, Skype and 3G CS Voice

4. Network Resource Analysis

5. Call Reliability, Call Setup Time and IRAT Handover Analysis
5.1 Call Setup Analysis
5.2 Call Reliability Analysis
5.3 eSRVCC Handover Analysis

6. Battery Life, Current Drain and Power Consumption Analysis
6.1 Level Setting
6.2 Highly Favorable Network Conditions
6.3 Average Network Conditions
6.4 Challenging Network Conditions
6.5 LTE versus Wi-Fi
6.6 VoLTE and Skype – a likely explanation

7. Test Methodology

8. Final Thoughts

9. Appendix

List of Figures

Figure 1. VoLTE MOS Test Results – IKEA, June 17th 1940 Hours
Figure 2. VoLTE MOS Test Results – IKEA, June 17th 1930 Hours
Figure 3. Skype Voice over LTE MOS Test Results – IKEA, June 17th 2015 Hours
Figure 4. Skype Voice over LTE MOS Test Results – IKEA, June 17th 2005 Hours
Figure 5. VoLTE MOS Test Results with Multiple Applications doing Network Transactions on
Different Phones and Datum Background Downloading on the Test Phone – IKEA, June 18th 1840 Hours
Figure 6. VoLTE MOS Test Results with only Angry Birds Downloading on a Different Phone – IKEA, June 18th 1920 Hours
Figure 7. Skype Voice over LTE MOS Test Results with Multiple Applications doing Network Transactions
on Different Phones – IKEA, June 18th 1850 Hours
Figure 8. Skype Voice over LTE MOS Test Results with Multiple Applications doing Network Transactions
on Different Phones – IKEA, June 18th 1900 Hours
Figure 9. Skype Voice over LTE MOS Test Results with Multiple Applications doing Network
Transactions on Separate Phones and Datum Background Downloading on the Test Phone –
IKEA, June 18th 1900 Hours
Figure 10. Skype Voice over LTE MOS Test Results with ONLY Angry Birds Downloading on a
Separate Phone – IKEA, June 18th 1920 Hours
Figure 11. Skype Voice over Wi-Fi MOS Test Results – lightly loaded network
Figure 12. Skype Voice over Wi-Fi MOS Test Results – moderately heavy to heavily loaded network
Figure 13. VoLTE Drive Test MOS Results – geo plot of St. Paul drive route
Figure 14. VoLTE Drive Test MOS Results – histogram
Figure 15. Skype Voice over LTE and HSPA+ Drive Test MOS Results – geo plot of St. Paul drive route
Figure 16. Skype Voice over LTE and HSPA+ Drive Test MOS Score Results - histogram
Figure 17. 3G CS MOS Drive Test MOS Results – geo plot of St. Paul drive route
Figure 18. 3G CS Drive Test MOS Score Results - histogram
Figure 19. Summary of Drive Test MOS Results
Figure 20. VoLTE MOS Results versus RSRP – first portion of drive route
Figure 21. Skype Voice over LTE MOS Results versus RSRP – first portion of drive route
Figure 22. Skype Voice over LTE and HSPA+ MOS Results – second portion of drive route
Figure 23. 3G CS Voice MOS Results – first portion of drive route
Figure 24. VoLTE Drive Test Downlink MAC Layer Throughput versus Time
Figure 25. VoLTE Drive Test Uplink MAC Layer Throughput versus Time
Figure 26. Skype Voice over LTE Drive Test Downlink MAC Layer Throughput versus Time
Figure 27. Skype Voice over LTE Drive Test Downlink MAC Layer Throughput versus Time
Figure 28. Downlink Resource Block Requirements – VoLTE versus Skype Voice over LTE
Figure 29. Uplink Resource Block Requirements – VoLTE versus Skype Voice over LTE
Figure 30. Summary of Resource Block Requirements – VoLTE versus Skype Voice over LTE
Figure 31. Distribution of Downlink TTI Requirements – VoLTE versus Skype Voice over LTE
Figure 32. Distribution of Uplink TTI Requirements – VoLTE versus Skype Voiceover LTE
Figure 33. Summary of TTI Requirements – VoLTE versus Skype Voiceover LTE
Figure 34. The Impact of DTX and DRX on VoLTE and Skype Voice
Figure 35. The Impact of RoHC on VoLTE and Skype Voice over LTE
Figure 36. The Impact of VoLTE and Skype Voice over LTE on PDCCH Signaling Messages without SPS
Figure 36. PUSCH Transmit Power versus RSRP – VoLTE and Skype Voice over LTE
Figure 38. Call Setup and Reliability Drive Route
Figure 39. Circuit Switched Fallback Time Results - Histogram
Figure 40. VoLTE Call Setup Time Results - Histogram
Figure 41. Comparing VoLTE and CSFB Call Setup Times
Figure 42. CSFB Call Setup Time – by message activity
Figure 43. VoLTE Call Setup Time – by message activity
Figure 44. 3G Voice Call Reliability
Figure 45. VoLTE Call Reliability
Figure 46. eSRVCC Handover Drive Test Route – average results
Figure 47. eSRVCC Handover #5 Drive Test Route – VoLTE and 3G CS MOS comparison with RSRP
Figure 48. Estimated Battery Life in Airplane Mode with Different Backlight Settings
Figure 49. Estimated Current Drain and Power Consumption in Airplane Mode with Different Backlight Settings
Figure 50. Estimated Battery Life Near the Serving Cell Site – Highly Favorable Conditions
Figure 51. Relative Battery Life Near the Serving Cell Site – Highly Favorable Conditions
Figure 52. Estimated Current Drain and Power Consumption Near the Serving Cell – Highly Favorable Conditions
Figure 53. Estimated Battery Life Near the Middle of the Cell – Average Conditions
Figure 54. Relative Battery Life Near the Middle of the Cell– Average Conditions
Figure 55. Estimated Current Drain and Power Consumption Near the Middle of the Cell – Average Conditions
Figure 56. Estimated Battery Life Near the Edge of the Cell – Challenging Conditions
Figure 57. Relative Battery Life Near the Edge of the Cell – Average Conditions
Figure 58. Estimated Current Drain and Power Consumption Near the Edge of the Cell – Average Conditions
Figure 59. Estimated Battery Life – VoLTE versus Skype over Wi-Fi
Figure 60. Relative Battery Life – VoLTE versus Skype over Wi-Fi
Figure 61. Estimated Current Drain and Power Consumption – VoLTE versus Skype over Wi-Fi
Figure 62. Skype over LTE Power Consumption and Current Drain
Figure 63. VoLTE Power Consumption and Current Drain
Figure 64. VoLTE Test Area
Figure 65. Quantum Display
Figure 66. VoLTE Drive Test MOS Score Results – probability distribution
Figure 67. Skype Drive Test MOS Score Results – probability distribution
Figure 68. 3G CS Drive Test MOS Score Results – probability distribution
Figure 69. Skype over LTE MOS Results versus RSRP – second portion of drive route
Figure 70. 3G CS Voice MOS Results – second portion of drive route
Figure 71. eSRVCC Handover #1 Drive Test Route – VoLTE and 3G CS MOS comparison with RSRP
Figure 72. Skype Voice over LTE MAC Layer Throughput versus Time
Figure 73. VoLTE MAC Layer Throughput versus Time
Figure 74. CSFB Message Flow
Note: Product cover images may vary from those shown
3 of 4

Loading
LOADING...

4 of 4
- 3G
- Skype
Note: Product cover images may vary from those shown
Order Online - visit: https://www.researchandmarkets.com/reports/3429767
Adroll
adroll