re 4.5.12 shows the steps of the scheduling procedure (ORAN-WG4.CUS.0) The downlink transmission procedure (Figure 4.5.12) is performed as follows: For given time slot "n," one or more control messages are sent by the O-DU to the O-RU. The O-RU makes preparation for receiving IQ data based on received control message(s). The O-DU sends the IQ data to the O-RU in multiple messages. The RU receives the IQ data, assembles the data in the right sequence, and puts I/Q data at allocated buffers. The above steps are repeated for the next subframe. The uplink transmitting procedure is similar and is therefore not shown here. C-Plane and DL U-Plane C-Plane and UL U-Plane (@ FH interface) (@ FH interface) (@ antenna) @ FH interface) control messages for U-Plane data for slot #n* control messages for U-Plane data for slot #n** network delay network delay tadv_cp_dl U-Plane IQ data for slot #n, OFDM symbol #0 #1 t2a_min_cp_u air Interface signals for slot #n. Initial symbol arrivos at the antenna U-Plane10 data-for slot#n OFDM symbol ta3_min min. time the RU U-Plane IQ data for slot #n, OFDM symbol #N-1 has prepare to U-Plane IQ data for slot #n. OFDM symbol #0 process DL data from the Ils-CU min. time the RU U-Plane IQ data for slot #n. OFDM symbol #1 has prepare to control messages for U-Plane.data for slot#n+1* process UL signals U-Plane IQ data for slot #n, OFDM symbol #N-1 at the antenna network delay control messages for U-Plane data for slot #n+ 1** tadv_cp_dl U-Plane IQ data for slot #n+1, OFDM symbol #0 #1 network delay -Plane TQ data for slot #p+1, OFDM symbol U-Plane IQ data for slot #n+1, OFDM symbol #N-1 t2a_min_cp_u air Interface signals for slot #n*1 Initial symbol arrivos at the antenna ta3_min *for multi-symbol C-Plane message, the message must be received Time flow U-Plane TQ data for slot #n+1, OFDM symbol by the RU *tadv_ cp dl* before the receipt by the RU of the U-Plane's U-Plane IQ data for slot #n+1, OFDM symbol #0 #1 lowest-numbered symbol in the C-Plane message U-Plane IQ data for slot #n+1, OFDM sy