Say a procedural exchange involves transmitting 6 one-way messages back and forth in the MO scenario with 1 additional message (paging) in the MT case. The delay in LEO is 2-30 ms and 120 ms in the GOS case. That is a total propagation delay of 12-180 ms for LEO and 720 ms for GEO. Additionally the time required for the transmissions – the time on air (TOA) – will depend on the size of the messages and the SNR conditions during the exchange. A quick estimate would be 6 ms ToA in a perfect scenario and 6 msgs x4 RUs x16 reps x32 RU duration (3.75kHz) = 12288 ms in a worst-case scenario. An additional overhead would stem from the transmission of the random access preamble (RAP) and any paging.