VoLTE for FOSS by Marius Gripsgard
Implementing VoLTE support for FOSS on mobile devices
FOSDEM23 track: Embedded Mobile And Automotive devices
Marius has been playing around with VoLTE* and Qualcomm Mediatek devices. He has got to the point where it is possible to make and receive calls and send and receive SMS messages on Ubuntu Touch ported devices. But it is still very hacky. Without any knowledge of the modem stack, it seemed very difficul! We are learning, and at the point where we are gaining insights into how it all works. Also it is possible to see how the binary blobs work. The way forward is to run Android and capture all the calls made to the drivers. Sailfish have some of it working, so their solution provided tools to help us succeed.
The fixes done so far are very specific. Every proprietary system has its own unique way of doing things. It is a horrible standard and so not a single carrier even follows the standard. In fact, the modem is a black box with no outputs. To be honest, when it works, we don’t know why it works. It now works perfectly well. In his talk at Fosdem, Marius would like to share his results, discuss them with the wider community and find ways how to roll this out to eventually support more devices.
Notes:
In the recent and coming years 2G and 3G are being phased out by network operators. Many Mobile Foss OSes that are Halium based will be useless because you can't make calls anymore. It has been extremely difficult to enable VoLTE service due all the proprietary components.
VoLTE stands for Voice over LTE, and LTE (Long Term Evolution) is better known as 4G. So essentially, VoLTE amounts to mobile calls over a 4G network.
