5G voice for smartphones: Network prerequisites

Everyone is talking about 5G and what it should be used for. Everyone probably expects that a 5G mobile phone should, by default, have all the capabilities a 4G mobile phone has plus new 5G capabilities—to justify the 5G icon visible on the screen. This also includes the capability to make regular operator voice calls; otherwise, it is not really a “phone” any longer. Learn what is needed to enable 5G voice in a mobile network.

Category & Hashtags

Even if voice support may not be the first question being asked when talking about 5G, it is one key topic in discussions with operators and the industry. Discussing voice support covers all the details that need to be taken into account, ranging from devices over radio to the network and the migration from today’s networks into 5G. There will also be other 5G use cases and devices types, but this blog post is focused on 5G voice.

Supporting voice in all 5G evolution steps

The industry has defined 5G such that there are several possible migration paths and steps. This has caused some confusion on which of those paths and steps are essential. Voice services must be supported in all 5G evolution steps. But which path and which steps are recommended? In this blog post, we share voice service aspects and our recommendations.



Experiences from standardizing 5G and 4G voice with 3GPP and GSMA

I have now been working with 3GPP and GSMA standardization for several years on how to deliver voice services in 4G and 5G networks. While 3GPP provides a high-quality technical specification, there are sometimes multiple solutions for the same problem, and sometimes it is unclear which solutions must be implemented by devices and networks.

GSMA provides recommendations and guidelines by selecting among existing alternatives and by selecting solutions that are essential. This aims to ensure device availability and interoperability, especially during roaming. However, recommendations on 5G from GSMA are not yet all settled; hence, I will share what the latest status is and our recommendations for a smooth network evolution to support all operators in delivering voice in 5G mobile phones.

Basics for 5G voice

5G as specified by 3GPP includes one 5G Evolved Packet Core (EPC) and four 5G Core (5GC)—based options for radio network deployment and packet core. An operator can deploy one or several of these options, but each operator has to decide which of these options are the right ones for their own deployment.

Smartphones require a voice service also in 5G. They will not select a 5G radio access unless they can detect a voice service. This means that voice must be supported in all 5G migration steps involving smartphones or similar voice-centric devices!

The industry has agreed that the IMS telephony service will continue to be used in 5G. Therefore, the voice evolution starts with 4G VoLTE. 4G VoLTE includes LTE RAN and packet core capabilities to support telephony characteristics. These capabilities for voice and emergency calls must be provided by the system, regardless of which 5G deployment option is being used.

You can start learning more about these first network evolution steps in a brochure we have prepared. In my next blog posts, I will share more about the other options and recommendations for how to introduce 5G voice in a mobile network. So stay tuned!

Do you want to know how to take the steps towards 5G voice in your network to give smartphones and other devices operator voice services? Download this brochure to learn more about the network architecture for 5G voice, and our recommendations for how to evolve your current network to prepare for 5G.


Download brochure




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