Over-the-air timing alignment compensation in a distributed radio access network

A distributed radio access network (RAN), comprising:

• a plurality of remote units (RUs), each being configured to exchange radio frequency (RF) signals with at least one user equipment (UE);
• and
• a centralized unit communicatively coupled to the plurality of RUs via a fronthaul network;
• wherein, during each of at least one measurement iteration:
• one of the plurality of RUs is selected as a transmit-mode RU and all other of the plurality of RUs are in receive-mode;
• the transmit mode-RU transmits a known pattern signal to the receive-mode RUs;
• and
• a frame or symbol boundary difference is determined between when the transmit-mode RU transmitted the known pattern signal according to its clock and when the respective receive-mode RU received the known pattern signal according to its clock;
• and
• wherein, following the at least one measurement iteration:
• the centralized unit determines a respective timing offset, indicating a timing difference between two of the plurality of RUs, based on each frame or symbol boundary difference.