Synchronization management in lower-layer split radio access networks

A method of synchronizing components in a Radio Access Network (RAN), comprising:

• receiving, by a timing Network Interface Card (NIC) of a first Distributed Unit (DU), first timing information from a Global Navigation Satellite System (GNSS) receiver;
• setting, by the timing NIC, an internal clock of the timing NIC using the first timing information;
• generating and transmitting, by the timing NIC, second timing information to a first Radio Unit (RU), wherein the first RU is managed by the first DU;
• synchronizing, by the first RU, an internal clock of the first RU to the internal clock of the timing NIC using the second timing information;
• generating and transmitting, by the timing NIC, third timing information to a second DU, wherein the second DU is connected to the timing NIC of the first DU;
• and
• synchronizing, by the second DU, an internal clock of the second DU to the internal clock of the timing NIC using the third timing information.

A Radio Access Network (RAN), comprising:

• a first Radio Unit (RU);
• a second RU connected to the first RU;
• a Global Navigation Satellite System (GNSS) receiver that receives time signals from one or more GNSS transmitters and generates first timing information from the time signals;
• a first Distributed Unit (DU) connected to the first RU, wherein the first DU manages the first RU, and the first DU comprises:
• a containerized Cell Site Router (cCSR) that routes user data, control data, or both between the first DU, the first RU, and one or more additional RUs of the RAN;
• and
• a timing Network Interface Card (NIC) connected to the GNSS receiver;
• wherein:
• the timing NIC uses the first timing information from the GNSS receiver to set an internal clock of the timing NIC;
• the timing NIC uses its internal clock to generate and transmit second timing information to the first RU;
• the first RU uses the second timing information to synchronize an internal clock of the first RU to the internal clock of the timing NIC;
• the first RU uses its internal clock to generate and transmit third timing information to the second RU;
• the second RU uses the third timing information to synchronize an internal clock of the second RU to the internal clock of the first RU, the internal clock of the timing NIC, or both.