Multicast already planned in 3G
Standardized mobile communications technologies for multicast transmissions have been around since 2006 when the Multimedia Broadcast Multicast Service (MBMS) subsystem was specified in 3GPP Release 6 (UMTS). With Release 9, it made its way into LTE in the form of evolved MBMS (eMBMS) and in Release 14 (LTE-Advanced Pro), it reached the current development stage dubbed Further evolved MBMS (FeMBMS). 3GPP has incorporated FeMBMS largely unchanged into Release 16 with the designation "LTE based 5G terrestrial broadcast" which is now an official component of 5G.
The technologies for terrestrial broadcasting and mobile communications have been converging for some time. Both are now based on signal feed over IP networks and OFDM at the air interface. The transmitter gets its payload and configuration data via 3GPP-compliant protocols. The signal conditioning of a DVB-T2 transmitter can be adapted to FeMBMS specifications with reasonable effort. The frequencies are already compatible if the signals are transmitted in the original TV bands, which were added to the mobile communications frequencies as a digital dividend during broadcasting digitalization or as a result of spectrum repacking.
Compatible end devices must support receive-only mode without a SIM card (free to air) so that the service can also address devices that are not registered in a mobile network, for instance television receivers.