Spirent, Signals Research study compares video telephony with OTT applications
Sunnyvale, Calif.– (Apr 9, 2015) — Spirent Communications, the leader in testing networks, services and devices, announced today that it has collaborated with the Signals Research Group (SRG) to complete the industry’s first benchmark study that compares video telephony using IR.94 with Over The Top (OTT) applications including FaceTime, Skype, Google Hangout amongst others. The study involved conducting more than 200 tests on one of the biggest commercial networks in North America. Focusing on the user experience, this study compared various KPIs that affect video telephony performance, including frame impairments, video freezes, audio/video synchronization problems, and current drain for all of the video chat applications. Spirent’s Chromatic Video Experience and Quantum Battery Life Measurement Systems were used to collect field data and generate the KPIs.
The key findings of this study are:
- Unlike IR.92 (VoLTE), there were not any obvious performance benefits associated with IR.94, compared with the most popular OTT video chat applications. However, an operator’s implementation of the feature can have a big influence on performance.
- Skype and FaceTime outperformed IR.94 video performance while IR.94 performed largely on par with the other OTT video chat applications that were tested. In general, Skype outperformed FaceTime with the best observed performance occurring with Skype running on the iPhone 6 Plus.
- Compared with most of the OTT video chat applications, IR.94 was relatively “network friendly” since it required far fewer network resources to support a video call. However, operators may still be reluctant to provide a guaranteed bit rate with QCI=2, due to the impact that it will have on the network design and other user-generated traffic.
- All video chat applications had a big impact on the battery life of the smartphone with very little differentiation between those applications that were tested. Consistent with earlier studies, VoLTE had far less impact on the battery life than the OTT applications when used in voice-only mode.
The study also reaffirmed earlier SRG work with Spirent, indicating that all OTT best-effort voice and video applications are severely impacted by network congestion and background applications running on the smartphone.
“While operators are likely to be challenged with balancing a bandwidth-intensive application such as IR.94 and managing network resources, the good news is that IR.94 gives the operators control over the video telephony service, including the tradeoffs between an enhanced video chat experience and the subsequent impact that it has on network resources,” said Michael Thelander, the President of the Signals Research Group. “Although this study revealed that IR.94’s overall performance was only on par or even worse than the OTT video chat applications, IR.94 does, or at least can, differentiate from OTT services in several ways. It will be interesting to see if operators drive the adoption of IR.94 or if it will remain a niche application for years to come.”
“It has indeed been rewarding to partner with the Signals Research group on this series of studies that dig deeper into the performance aspects of VoLTE and video telephony services,” said Saul Einbinder, Vice President of Marketing for wireless at Spirent Communications. “As operators and device vendors work to leverage IR.94 flexibility to their advantage, we see significant value in conducting these studies to reveal the challenges our customers will face, since we are dedicated to providing the tools and services required to ultimately deliver a guaranteed user experience.”
This study is the latest in a series of collaborations between Spirent and Signals Research Group on VoLTE-related studies. The report follows on the heels of a Video Performance study published in February this year that quantified the video playback capabilities of multiple devices over a commercial LTE network.
For a more detailed report of the report by the Signals Research Group, “Behind the VoLTE Curtain, Part 3: Benchmark Study of IR.94 and Multiple over-the-Top (OTT) Video Chat Applications”, please visit the consultancy’s website at www.signalsresearch.com.
For more information on Spirent’s Chromatic Video User Experience Analytics System, please visit http://www.spirent.com/Products/User_Experience_Evaluation.
For more information on Spirent’s Quantum User Experience Analytics System, please visit http://www.spirent.com/Products/User_Experience_Evaluation.