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Comment by kop316 | Hacker News Reader

I hate to temper your excitement a little bit (I am excited too!), but I am not a bit surprised that LTE data works. Calling and SMS/MMS over LTE (for T-Mobile USA) are two things that at least that as of today, you need proprietary libraries to have it function on Android, and likely don't work on the Pinephone. I strongly suspect that other USA carriers will have the same issue (I say that because there are additionally several proprietary Verizon and Sprint blobs that are resident in factory images that need to be put in third party ROMs).

The Librem 5 has LTE mobile data as well, but it has those same issues (no VoLTE, SMS only over 3g, no MMS for T-Mobile USA). I am hopeful that between Purism and the Pinephone community that this is a solvable (but lengthy) issue.

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Calling and SMS works without proprietary software already. The ubPorts people already did it:

https://twitter.com/thepine64/status/1202162774186582017

Is it on 3g or LTE?

I wouldn't be surprised if both work over 3g, but I would be very surprised if it works over LTE.

While the baseband runs Linux (IIRC PinePhone uses a Quectel modem), it probably runs proprietary software for the full LTE/3G/2G stack.

https://osmocom.org/projects/quectel-modems/

Is that really where the goalpost is though? I thought everyone accepted that the modem itself would always be proprietary, and that was OK as long as it had a killswitch and no ability to directly interfere with the main processor or RAM. (The mostly-userland stack to drive the modem to send SMS etc. would be open.)

It seems right to me that the FCC et al shouldn't allow uncertified amateur radio firmwares.

Depends on the human defining where the goalpost is, what their threat model is and their philosophy etc. There are certainly folks who want open basebands enough to work on them, for example there are folks working on porting the Osmocom baseband codebase to Mediatek based phones.

https://osmocom.org/projects/baseband https://media.ccc.de/v/osmodevcon2019-109-osmocombb-layer1-o...

Want and need are different. If you don't have a phone now, you might wait for an open baseband. If you have a a closed phone now, it's silly to wait.

"Is that really where the goalpost is though? I thought everyone accepted that the modem itself would always be proprietary, and that was OK as long as it had a killswitch and no ability to directly interfere with the main processor or RAM."

Most of the time when we speak about the baseband, we are talking about the telco network interface between your handset and the carrier ... and so it's tempting to think of the baseband as just some black-box modem that you can firewall yourself from.

However, the baseband processor also performs a number of real-time voice quality / noise cancelling / audio functions that really have nothing to do with the network interface, but are very important depending on how sensitive you are to call quality and things like echo, etc.

This is unfortunate because, like you, I would like to just wall of the baseband and use it as a modem and forget about it, but that perceptible difference in call-quality between "actual carrier" calls and VOIP calls is due to the baseband.

I believe that is all still true in the 2019 LTE era ...

Could you just bypass that and use VOIP?

VOIP over 3g is terrible, and over LTE it's only slightly better. Latency and jitter are both very high, which makes it somewhat hostile to VOIP.

VOIP over LTE has been rock solid in my experience with T-Mobile on the east coast. I regularly get on (hands-free) VOIP Zoom calls during my 20 mile commute and almost never have any latency or packet loss issues.

I'm on Tingb(mvno using the T-Mobile networj) and on the West coast. Both zoom and Skype are completely unusable for me.

FWIW, I've been using VOIP for over a year now. I don't make a massive number of calls, but it's perfectly usable over LTE in Western Canada.

Same experience here, using https://voip.ms with Fido.

LTE latency is more than adequate for VoIP, with RTT latency to the tower being around 25ms. Adding another 40, 60, whatever, internet latency for VoIP is still well within the realm of good call quality.

Fair enough. I must have a shitty network. I see 150-200ms pings through LTE with occasional spikes up to 500ms, and any VOIP is both poor quality and we end up talking over each other because of the latency.

Don't all messaging apps like Viber, Whatsapp, telegram etc technically use VOIP, or at least the same type of technology as VOIP? The quality is quite good, for a lot of people.

T-Mobile USA's system is bog-standard IMS with RCS extensions. There are a few open source client stacks that support this, notably Doubango's. The trick is writing a frontend that uses regular Linux GUI libraries. As far as I know, nobody has done that yet...

It could probably be implemented aa a plugin for Telepathy, which already has mobile-focused UI for multiple platforms.

Telepathy seems to be dying on desktop GNU/Linux, the existing clients in GNOME/etc are being replaced by protocol-specific applications. New protocol plugins seem to happen more in Pidgin/libpurple these days.

Any idea if Doubango has IMS/RCS libraries that could be used for implementing a Linux frontend?

This seems to be their GitHub:

https://github.com/DoubangoTelecom/doubango

It looks like it could be. They have client-side proof of concepts.

Well screw T-Mobile then honestly. This in addition to their (from what I understand) abuse of the FCC TV white space database kind of undoes any goodwill they had in my mind.

I don't know if it's just T-Mobile doing that. I've never tried using AT&T, Verizon, or Sprint with a purely AOSP (only compiled using the instructions on Android's website, not also including other proprietary blobls) or with my Librem 5, so I don't know if this is a T-Mobile only thing, or if it's industry wide.

Could I get more details on T-Mobile's abuse of the FCC's TV Whitespace database? I know they currently do spectrum hijacking with License Assisted Access in the 5Ghz band, I'm curious what their other abuses are tho.

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