SMS uses servers, those servers just happen to be your telco’s servers. RCS was designed to work the same way, exchanging messages via servers hosted by carriers.
Nobody cared about RCS so Google took it upon themselves to host their own RCS server. Now most people who use RCS, use Google’s servers.
Assuming spec compliancy, anyone can make an app that communicates with a carrier’s servers, or with Google’s servers for that matter. In practice, the standard is obscure and the lack of system integration will have RCS apps fighting over who gets to do the RCS registration for your phone number.
Custom ROMs and such will probably get RCS support outside of Google Messages at some point in the future, and perhaps rooted phones will be able to use those same apps as well when that eventually happens. However, as it stands, RCS on Android would allow you to use one single app for rich messaging, and all other apps (including the Android system APIs) would have to fall back to SMS.
Furthermore, the RCS Google supports actually uses an E2EE scheme that isn’t publicly documented. That means your custom RCS app will likely need to reverse engineer Google’s encryption code (I believe it’s based on Signal for one on one, and MLS for groups?) or you won’t be able to read half of the messages.
SMS only transits the telco infrastructure, it doesn’t need servers in the client-servers sense, RCS does. Not only that but RCS needs them because it includes hosting for things like images and videos that are sent in messages.
I don’t think Google will allow anybody to partake in “their” RCS, the least of all custom ROMS. They will make it another thing like SafetyNet, designed to maintain their own control.
SMS very much needs servers. SMS messages go from your device to the SMSC which will store the message and try to transmit it to your phone in case your phone isn’t on or connected. In theory you could set up direct SMS messaging, but in practice there’s a layer of indirection because messages would get lost.
Since SMS can’t do anything but text, MMS is required to send images and videos, and those too travel through an MMSC so messages are available when your phone is offline (or if it doesn’t support MMS, which was something MMS had to be designed for). MMS can’t work directly between clients, it had to go through a server.
Like everything designed for carriers, MMS is a mess of moving parts and optional services that only a committee could’ve designed:
SMSCs and MMSCs may not be available over the internet, but they are very much a client-server architecture. The store-and-forward server approach is also what Signal and supposedly WhatsApp use.
SMS uses servers, those servers just happen to be your telco’s servers. RCS was designed to work the same way, exchanging messages via servers hosted by carriers.
Nobody cared about RCS so Google took it upon themselves to host their own RCS server. Now most people who use RCS, use Google’s servers.
Assuming spec compliancy, anyone can make an app that communicates with a carrier’s servers, or with Google’s servers for that matter. In practice, the standard is obscure and the lack of system integration will have RCS apps fighting over who gets to do the RCS registration for your phone number.
Custom ROMs and such will probably get RCS support outside of Google Messages at some point in the future, and perhaps rooted phones will be able to use those same apps as well when that eventually happens. However, as it stands, RCS on Android would allow you to use one single app for rich messaging, and all other apps (including the Android system APIs) would have to fall back to SMS.
Furthermore, the RCS Google supports actually uses an E2EE scheme that isn’t publicly documented. That means your custom RCS app will likely need to reverse engineer Google’s encryption code (I believe it’s based on Signal for one on one, and MLS for groups?) or you won’t be able to read half of the messages.
SMS only transits the telco infrastructure, it doesn’t need servers in the client-servers sense, RCS does. Not only that but RCS needs them because it includes hosting for things like images and videos that are sent in messages.
I don’t think Google will allow anybody to partake in “their” RCS, the least of all custom ROMS. They will make it another thing like SafetyNet, designed to maintain their own control.
SMS very much needs servers. SMS messages go from your device to the SMSC which will store the message and try to transmit it to your phone in case your phone isn’t on or connected. In theory you could set up direct SMS messaging, but in practice there’s a layer of indirection because messages would get lost.
Since SMS can’t do anything but text, MMS is required to send images and videos, and those too travel through an MMSC so messages are available when your phone is offline (or if it doesn’t support MMS, which was something MMS had to be designed for). MMS can’t work directly between clients, it had to go through a server.
Like everything designed for carriers, MMS is a mess of moving parts and optional services that only a committee could’ve designed:
SMSCs and MMSCs may not be available over the internet, but they are very much a client-server architecture. The store-and-forward server approach is also what Signal and supposedly WhatsApp use.