Is matter actually an open standard? When I last looked into the CSA stuff you had to pay a few thousand dollars a year to become a member to access any specifications
My understanding is that the standard will be open when it's final, but the working draft is not. The reference implementation is open during development: https://github.com/project-chip/connectedhomeip
Disclaimer: not speaking for my employer or CSA/Matter (I have done paid work on the reference implementation).
Setting aside the radio incompatibilities, various web articles says Matter was Zigbee Alliance "Project CHIP" and later rebranded to "Matter". And "CSA Connectivity Standards Alliance" is itself a rebranding of "Zigbee Alliance".
If the pdf reference docs are not relevant, I guess I don't understand why they're hosted at the domain "csa-iot.org".
As I understand it, Matter uses Thread to communicate with low power devices.
Thread uses the IEEE 802.15.4 PHY and MAC.
Zigbee also uses the IEEE 802.15.4 PHY and MAC, using the same frequency bands as Thread as far as I understand it.
Maybe a new radio is needed if you want BLE commissioning (is this required?), but for operation any chip with a IEEE 802.15.4 PHY should support both Thread and Zigbee.
I think it can run on wifi or Thread (possibly zigbee too if I’m reading the wiki right) but I may be wrong. It also uses BLE but I think only for initial setup.