[AAAAaccountAAAA]

RCS in its standard form is to be offered by the carriers. However, because carriers in the most parts of the world refused to offer the service, Google took over that role.

https://www.theverge.com/2019/6/17/18681573/google-rcs-chat-...

Apple has so far been quiet about how, if at all, they are going to deal with carriers that have no native RCS support. Maybe they will run their own servers and federate with Google, maybe they will use Google's servers directly, or maybe it simply won't work at all without carrier support. We have no idea yet.

Edit: IMO the most worrying option would be that Apple and Google will make a some sort of exclusive bilateral deal that will make them, and only them, to be able to offer non-carrier-based RCS support, locking out any other operating system vendors from the platform. That would probably have antitrust implications, but enforcement is often slow.

[asdaq1312512]

Is RCS possible without phone number? Like, Google would just set up an RCS server that accepts GMail addresses, and only falls back to your contact's phone number if they can't route the message? I just find it odd to have carriers involved at all (through the phone number), but sure, it's probably compelling to use an established concept.

[AAAAaccountAAAA]

Not sure if I understood it correctly, but this specification seems to discuss about SIP URI based non-mobile identities: https://www.gsma.com/futurenetworks/wp-content/uploads/2019/...

[asdaq1312512]

Thanks!