Most smartphones have the hardware necessary to make Voice over LTE (VoLTE) calls, delivering lower latency and better audio quality than phone calls that don’t use the technology. If you’re using an Android or iOS phone, then all you need to take advantage of VoLTE is a mobile network that supports the feature.
But if you’re running Linux on your phone? You’ll also need a GNU/Linux distribution that supports VoLTE. And now the folks behind Ubuntu Touch want to make sure that they’re operating system can do it.
The UBPorts Foundation has commissioned a report to investigate what it would take to add VoLTE support to Ubuntu Touch and the next step is to begin development of the code that will make it happen.
Ubuntu Touch is designed to run on a number of phones that already have the modem firmware necessary to support VoLTE. For example, the Volla Phone is a smartphone that’s designed to ship with either Android or Ubuntu Touch, but the hardware is identical. If you buy an Android version of the phone it already supports VoLTE, but the Ubuntu Touch version does not… because the OS doesn’t know how to talk to the modem.
So the plan is to add support by creating an open source, Linux-compatible alternative to the proprietary IP Multimedia Subsystem (IMS) software that’s normally used to make VoLTE calls. To do this it will be necessary to add support for each modem chipset, so the goal is to begin by building a vendor-specific version version of the software that supports the Volla Phone. But there’s a good chance that it will also work with other devices featuring the same modem with little to no changes.
The work that goes into developing an open source IMS should make it possible to make VoLTE calls… but UBPorts expects it will also let users place calls over WiFi since Voice over LTE and Voice over WiFi are both based on the same 3GPP IMS framework.
UBPorts says Sysmocom, the firm that was hired to do the initial report, will begin development of a command-line open source IMS client and once it’s ready, the UBPorts team will take over development in order to add it to the Ubuntu Touch dialer app.
For what it’s worth, Ubuntu Ports wouldn’t be the first GNU/Linux distribution to support VoLTE. You can already make VoLTE calls on a PinePhone using most operating systems that run on the phone. But the work the UBPorts and Sysmocom are doing should make VoLTE more widely available on a range of phones including models that initially shipped with Android.