Rhode & Schwarz: Voice over New Radio (VoNR) should be ‘considered a prerequisite for successful 5G deployment in Standalone operation’

In cloud-native 5G Standalone (SA) networks, operators can deliver high-quality voice services without having to rely on LTE as an anchor. Instead, operators can offer Voice over 5G New Radio (VoNR), which fully utilizes the SA architecture of 5G networks and provides significantly lower latency and improved sound quality, while providing 5G speeds for data-driven activities throughout the duration of the voice calls.

According to a Rhode & Schwarz white paper, because of the increase of voice services, VoNR should be “considered […] a prerequisite for successful 5G deployment in standalone operation.”

Beyond providing improved voice services, VoNR is expected to make possible many 5G SA-enabled data services like video conferencing or augmented and virtual reality features.

5G Voice over New Radio network architecture

VoNR network architecture consists of a 5G RAN and 5G core and, like 4G LTE networks, 5G voice calls are implemented as end-to-end Voice over IP (VoIP) connections managed by the IP Multimedia System (IMS) core. Originally developed by the 3GPP, IMS specification is a standards-based architectural framework for delivering multimedia communications services.

The Rhode & Schwarz white paper explains that the advantage of integrating IMS into the deployment scenario is that IMS “manages (like in VoLTE) the [Protocol Data Unit or] PDU session establishment with the relevant QoS flow for optimized voice quality.”

“This IMS architecture will play an increasingly important role in 5G VoNR,” stated the white paper. “While IMS can provide voice services for any type of access (fixed, cable and 2G/3G) as well as for any 5G-deployment model, 5G is not as flexible and absolutely has to have an IMS network to handle voice services no matter the type of deployment.”

DT trialing 5G Voice over New Radio

In June, Deutsche Telekom announced the completion of a 5G Voice over New Radio call in partnership with Ericsson, Nokia, Qualcomm, Samsung and Xiaomi. Made at the carrier’s lab in Warsaw, Poland, the network setup integrated a 5G Core from Ericsson and IMS from Nokia. The calls were completed using the Samsung Galaxy S21 5G, Xiaomi Mi 11 Lite 5G, and a 5G smartphone-form-factor test device powered by the Snapdragon 780G and 888 5G Mobile Platforms with Snapdragon 5G Modem-RF Systems.

“High quality and seamless voice calling remains a must-have service for our customers in the 5G era,” said Alex Choi, SVP Strategy & Technology Innovation, Deutsche Telekom. “The addition of 5G VoNR can be a differentiator for next generation immersive applications that integrate high speed 5G data with high-definition audio.”

A month later, Singaporean operator M1 Limited hit a more significant milestone when it made VoNR available to Samsung Galaxy S21 Ultra, S21+ and S21 users on its 5G SA network via an over-the-air software update. According to M1, these users became amongst the first in the world to enjoy the benefits of a Voice over New Radio service.