Methods, systems, and devices for wireless communications for determining a minimum time gap between an received downlink message and transmission of an uplink message in response to the received downlink message. In some cases, a user equipment (UE) may receive a downlink message to perform a random access procedure. The UE may determine a minimum time gap based on an uplink transmission preparation time. The UE may transmit a random access preamble based on the minimum time gap. In some examples, the UE may receive a timing advance (TA) command and may determine a minimum time gap between receipt of the TA command and transmission of a time-adjusted uplink message.