Network synchronization for MBS SFN

A method of wireless communication at a distributed unit (DU), comprising:

• receiving, from a central unit (CU) of a plurality of CUs, a downlink user plane (UP) container based on an F1-U UP protocol, wherein the downlink UP container includes:
• downlink user data for a multicast broadcast service (MBS) single frequency network (SFN) data transmission,
• a sequence number for packet loss detection, and
• a synchronization information element (IE) that indicates synchronization timing information for the MBS SFN data transmission in a synchronous manner with at least one additional DU, wherein the synchronization IE includes:
• a timestamp of a synchronization protocol added to the downlink user data, and
• a packet number associated with the timestamp, wherein the packet number is regenerated based on another packet number in a core network-radio access network (CN-RAN) synchronization protocol between the plurality of CUs and the core network;
• and
• sending the MBS SFN data transmission with a timing based on the synchronization timing information received from the CU.

An apparatus for wireless communication at a central unit (CU) of a plurality of CUs, comprising:

• memory;
• and
• at least one processor coupled to the memory, the at least one processor configured to:
• send a downlink user plane (UP) container based on an F1-U UP protocol, wherein the downlink UP container includes:
• downlink user data for a multicast broadcast service (MBS) single frequency network (SFN) data transmission,
• a sequence number for packet loss detection, and
• a synchronization information element (IE) that indicates synchronization timing information for the MBS SFN data transmission in a synchronous manner to multiple distributed units (DUs), wherein the synchronization IE includes:
• a timestamp of a synchronization protocol added to the downlink user data, and
• a packet number associated with the timestamp, wherein the packet number is regenerated based on another packet number in a core network-radio access network (CN-RAN) synchronization protocol between the plurality of CUs and the core network;
• and
• send the MBS SFN data transmission to the multiple DUs for synchronous transmission to one or more user equipments (UEs).

A method of wireless communication at a central unit (CU) of a plurality of CUs, comprising:

• sending a downlink user plane (UP) container based on an F1-U UP protocol, wherein the downlink UP container includes:
• downlink user data for a multicast broadcast service (MBS) single frequency network (SFN) data transmission,
• a sequence number for packet loss detection, and
• a synchronization information element (IE) that indicates synchronization timing information for the MBS SFN data transmission in a synchronous manner to multiple distributed units (DUs), wherein the synchronization IE includes:
• a timestamp of a synchronization protocol added to the downlink user data, and
• a packet number associated with the timestamp, wherein the packet number is regenerated based on another packet number in a core network-radio access network (CN-RAN) synchronization protocol between the plurality of CUs and the core network;
• and
• sending the MBS SFN data transmission to the multiple DUs for synchronous transmission to one or more user equipments (UEs).