Is RCS an open standard?

https://lemm.ee/post/24137479

Is RCS an open standard? - lemm.ee

Is RCS an open standard? I’ve seen some people say it is and others it isn’t and now I’m very confused. Can you please give me a definitive answer?

Yes it is, it’s been developed by the GSM Association, but Google does have de facto monopoly in the market right now by their Jio virtual carrier. RCS can be freely implemented by carriers and device manufacturers independently of that, but so far only Samsung, T-Mobile USA and Verizon did so — everyone else uses Google’s Messages. Importantly, different RCS implementations can talk to each other, just like email servers of Lemmy instances.
What’s that about Jio? I use Jio and Airtel and both support RCS so… I’m confused…
They said Google has a monopoly using their own Jio virtual carrier. They never said Jio doesn’t support RCS.

I might need to read up on what a virtual carrier means…

Any suggestions?

I really wouldn’t know. In this context I assume it means it is not deployed like traditional mobile networks are. The missing components being the hardware side like putting up towers etc.
I see… Well, thanks anyway 🫡