VoLTE in Australia

Introduction

In Australia the 3G mobile frequencies are to be reused so they are in the process of shutting down the 3G service. That means that everyone has to use VoLTE (Voice Over LTE) for phone calls (including emergency calls). The shutdown time varies by telco, Kogan Mobile (one of the better services which has good value for money and generally works well) shut down their 3G service in January. Aldi Mobile (another one of the good services which is slightly more expensive but has included free calls to most first-world countries and uses the largest phone network) will shut theirs down at the end of August.

For background there’s a Fosdem talk about OpenSIPS with VoLTE and VoNR [1], it’s more complex than you want to know. Also VoNR (Voice over New Radio) is the standard for 5G voice and it’s different from VoLTE and has a fallback to VoLTE. Another good lecture for background information is the Fosdem talk on VoLTE at the handset end [2].

The PinePhonePro

In October 2023 I tried using my PinePhonePro as my main phone but that only lasted a few days due to problems with calls and poor battery life [3]. Since then I went back to the Huawei Mate 10 Pro that I bought refurbished in June 2019 for $389. So that has been my main phone for 5 years now, giving a cost of $1.50 per week. I had tried using a Huawei Nova 7i running Android without Google Play as an experiment but that had failed, I do many things that need Android apps [4].

I followed the PinePhone wiki to get my PinePhonePro working with VoLTE [5]. That worked fine for me, the only difference from the instructions is that I had to use device /dev/ttyUSB3 and that the modem kept resetting itself during the process and when that happened I had to kill minicom and start again. After changing the setting and saving it the PinePhonePro seemed to work well with VoLTE on a Kogan Mobile SIM (so definitely not using 3G).

One issue I have found is that Plasma Mobile (my preferred FOSS phone GUI) appears to have a library issue that results in polling every 14ms even when the screen is locked [6]. If you have a few processes doing that (which means the most lightly used Plasma system) it really hurts battery use. The maintainer has quite reasonably deferred action on this bug report given the KDE 6 transition. Later on in the Trixie development cycle I hope to get this issue resolved, I don’t expect it to suddenly make battery life good. But it might make battery life acceptable.

I am now idly considering carrying around my PinePhonePro in a powered off state for situations where I might need to do high security operations (root logins to servers or online banking) but for which carrying a laptop isn’t convenient. It will do well for the turn on, do 30 mins of work that needs security, and then turn off scenario.

Huawei Mate 10 Pro and Redmi 9A

The Huawei Mate 10 Pro has been my main phone for 5 years and it has worked well, so it would be ideal if it could do VoLTE as the PinePhonePro isn’t ready yet.

All the web pages I’ve seen about the Mate 10 Pro say that it will either allow upgrading to a VoLTE configuration if run with the right SIM or only support it with the right SIM. I did a test with a Chinese SIM which gave an option of turning on VoLTE but didn’t allow any firmware updates and the VoLTE option went away when I put an Australian SIM in. Some forum comments had led me to believe that it would either permanently enable VoLTE or allow upgrading the firmware to one that enables VoLTE if I used a Chinese SIM but that is not the case. I didn’t expect a high probability of success but I had to give it a go as it’s a nice phone.

I did some tests on a Redmi 9A (a terrible phone that has really bad latency on the UI in spite of having reasonably good hardware). The one I tested on didn’t have VoLTE enabled when I got it, to test that I used the code *#*#4636#*#* in the dialler to get the menu of SIM information and it showed that VoLTE was not provisioned. I then had to update to the latest release of Android for that phone and enter *#*#86583#*#* in the dialler to enable VoLTE, the message displayed after entering that magic number must end in “DISABLE”. I get the impression that the code in question makes the phone not check certain aspects of whether the carrier is good for VoLTE and just do it. So apparently Kogan Mobile somehow gives the Redmi 9A the impression that VoLTE isn’t supported but if the phone just goes ahead and connects it will work. I don’t plan to use a Redmi 9A myself as it’s too slow, but I added it to my collection to offer to anyone else I know who needs a phone with VoLTE and doesn’t use the phone seriously or to someone who needs a known good phone for testing things.

Samsung Galaxy Note 9

I got some Samsung Galaxy Note 9 phones to run Droidian as an experiment [7]. But Droidian dropped support for the Note 9 and I couldn’t figure out how to enable VoLTE via Droidian, which was very annoying after I had spent $109 on a test phone and $215 on a phone for real use (I have no plans to try Droidian again at this time). I tried installing LineageOS on one Note 9 [8] which was much easier than expected (especially after previously installing Droidian). But VoLTE wasn’t an option. According to Reddit LineageOS doesn’t support VoLTE on Samsung devices and you can use a “magisk” module or a VoLTE enabler module but those aren’t supported by LineageOS either [9].

I downloaded an original image for the Note 9 from SamsMobile.com [10]. That image booted past the “orange stage” (where if you have problems then your phone is probably permanently useless) but didn’t boot into the OS. A friend helped me out with that and it turned out that the Heimdal flash tool on Linux didn’t do something it needed to do and that Odin on Windows was required. After using Odin everything was fine and I have a Note 9 with VoLTE running the latest Samsung firmware – which is security patch level 1st July 2022!!!

So I have a choice between using a Note 9 for data and SMS while running a current version of Lineage OS with all security fixes or running a Samsung image with no security updates for 2 years which supports phone calls. So based on this I have to recommend Pixel as the phone of choice, it has a decent level of support from Google and long term support from LineageOS. According to the LineageOS web site you can run the current version of Lineage on the original Pixel phone from 2016! Of course getting VoLTE to work on it might be another saga, but it would probably be easier to do with LineageOS on a Pixel than on a Samsung phone.

Conclusion

The operation of the Note 9 for me is decent now apart from the potential security issues. The same goes for selling one of the phones. The PinePhonePro still has potential to become my daily driver at some future time if I and others can optimise power use. Also a complicating factor is that I want to have both Jabber and Matrix be actually instant IM systems not IM with a 5 minute delay, so suspend mode isn’t a good option.

Pixel phones will be a much higher priority when looking at phones to buy in future. The older Pixel phones go for as little as $100 on eBay and can still run the latest LineageOS.

VoLTE seems needlessly complicated.

• [1] https://tinyurl.com/2y4ul68z
• [2] https://tinyurl.com/27sa46fz
• [3] https://etbe.coker.com.au/2023/10/11/pinephone-status/
• [4] https://etbe.coker.com.au/2022/04/20/android-without-play/
• [5] https://wiki.pine64.org/wiki/PinePhone#VoLTE
• [6] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1073294
• [7] https://etbe.coker.com.au/2024/04/28/note9-droidian/
• [8] https://download.lineageos.org/devices/crownlte/builds
• [9] https://tinyurl.com/2652h7vk
• [10] https://www.sammobile.com/