Vol 27: Behind the VoNR Curtain

08/30/2022 | 47 pages
Price: $1,550.00

SRG just completed its 27th 5G NR benchmark study. For this endeavor we collaborated with Accuver Americas and Spirent Communications to conduct an independent benchmark study of Voice over New Radio (VoNR) and how it compares with VoLTE, based on testing we did in T-Mobile’s network.

Highlights of the Report include the following:

Our Thanks. We did this study in collaboration with Accuver Americas (XCAL-M and XCAP) and Spirent Communications (Umetrix Voice and Umetrix Data). SRG is responsible for the data collection and all analysis and commentary provided in this report.

Our Methodology. Testing took place over a two-day period in early July. We had access to a T-Mobile 17-site test cluster that is part of its commercial network. Using 2 Galaxy S21 with pre-release software that supported VoNR and SA we did comparative drive and stationary testing with two Galaxy S20 smartphones that supported VoLTE. We tested VoNR in both Band n71 (600 MHz) and Band n41 (2500 MHz), including with background data transfers taking place during the call.

Four Areas of Focus. We looked at voice quality (MOS), network resource utilization, background data transfers, and current consumption. We did this comparative testing while stationary and/or via extensive drive testing throughout the cluster where the smartphones were exposed to a wide range of RF conditions.

Its Nuanced. VoLTE offered a huge advantage over circuit switched 3G voice in terms of superior voice quality, not to mention the elimination of CSFB (circuit switched fallback). VoNR and VoLTE both use the same EVS codec so the benefits of VoNR over VoLTE are less obvious.

“Staying Alive” on 5G. Without question, the biggest advantage of VoNR is that it allows the smartphone to remain on 5G, which proves beneficial when background data transfers occur. Longer term, moving all traffic to 5G SA helps with technology migration while SA offers certain performance benefits over NSA that are unrelated to voice.

Balancing Act. 5G networks are not as mature as LTE so RF conditions are not always as favorable. 5G current consumption is a consideration, especially when VoNR occurs in Band n41. Lastly, 5G network resource utilization can be better optimized for low bit rate voice calls.