The Pixel 3A and Pixel 3 are marketed as compatible phones with T-Mobile.
Pixel 3A and Pixel 3 are compatible with the next-generation text message protocol called Universal Profile for RCS (or Rich Communication Services, or Chat).
T-Mobile is compatible with RCS.
But Pixel 3A and Pixel 3 will not have RCS chat in the T-Mobile network. How is it so broken?
When Google first revealed its compatibility plans with RCS Chat on Android in April 2018, I wanted to believe that it could move quickly to replace SMS on Android phones. RCS Chat is not yet an end-to-end encrypted communication service, but at least it would offer better chat features such as higher-order reading receipts, group chats and attachments.
Pixel phones do support RCS in many operators, including Verizon, Sprint and Google's own Fi network (which, in a delicious irony, is an MVNO that theoretically provides access to several cellular networks, but it generally puts me in the towers of T-Mobile). Many Android phones in the T-Mobile network are also compatible with RCS, although full compatibility with Universal Profile is still pending.
I was hoping that this implementation was almost finished at this point because Google itself was in RCS, to the point where it closed or will soon close almost all its consumer-oriented text messaging applications (and yes, Han been many of them). Google is not the company that currently runs RCS (although it will happily sell services to operators to do so), but has acted as a diplomat so that all operators accept and support it through Android.
A year later, progress in the United States has been ridiculously slow. Verizon, Sprint and T-Mobile are compatible with the Universal Profile, which guarantees that you can send text messages to people in different operators. But it seems that only the support of RCS at operator level is not enough to guarantee that you will get it if you are a client. Apparently, operators need to approve support for each phone model one by one as they enter the network. Apparently, T-Mobile has not done that with Pixel phones, as you'll see below.
Maybe. I could be wrong! The technical details are very unclear to me. I am not an expert in RCS, I only play one on TV. I have asked Google and T-Mobile to explain what is happening here, but in the meantime, the best we have are these T-Mobile support tweets that 9to5Google found:
For the category of wireless provider performance. Our advanced messaging RCS capabilities are integrated into the core of the network instead of individual applications or devices, and pixels currently do not support this network-level authentication. ^ MarvaBiggar
– Help from T-Mobile (@TMobileHelp) May 9, 2019
Great question, Joshua. The Galaxy S7, S7 Edge, S8, S8 +, S8 active, Note 8, S9, S9 + and Note 9 are currently compatible with RCS Universal Profile 1.0 and we are planning to enable RCS Universal Profile 1.0 for more Android devices this year. DM us if you have questions. ^ MichaelMarks
– Help from T-Mobile (@TMobileHelp) May 9, 2019
It is very difficult to accurately convey all the technical nuances behind whether, why and how operators support or not the universal profile. for RCS. A carrier could support RCS but not the Universal Profile. An operator could support RCS, but apparently could not be completely connected to the interconnection that makes it work with other operators. Here is a Google spreadsheet collaborated by Reddit that remains the best source of information about what is happening. (Note that AT & T is basically not anywhere in the Universal Profile, for example).
If you're looking for someone to blame, there's also a useful Reddit thread for that. But the answer is simple: blame everyone. Blame Google for fixing such an essential feature in the whims and fantasies of the carriers. It blames operators for being more interested in promoting 5G technologies that are virtually non-existent instead of replacing their outdated SMS systems.
I have a reputation for going to message messages and, well, reputation is confirmed. Last night, during our live Vergecast, I asked Hiroshi Lockheimer, who is in charge of Google's communication products, to talk about the status of RCS. He was not referring to T-Mobile specifically, but he said this about RCS in the United States: "I'll be honest, and I mentioned it to [carriers] I'm a little frustrated by the pace of it.
Internationally, RCS is doing much better, at least, according to the giant Reddit spreadsheet.
One final note: even if all these partners can take a break talking about how wonderful 5G is, it will be some day and start working on real and interoperable RCS, the standard still has a fundamental problem. It is not encrypted end-to-end, so any government can easily quote an operator to get access to their chats. I asked Lockheimer specifically about that and he said "we can address those things … I'm sure we can evolve the standard to handle these cases."
I hope that is true, and I hope it will happen in a cleaner way than the current implementation of RCS in the US. UU Until then, there is nothing to do but wait. I will update this post if I receive a response from T-Mobile or Google about why Pixel phones will not have RCS on that network.