Apparatus comprising: at least one processor; and at least one memory including computer program code which, when executed by the at least one processor, causes the apparatus: to generate (S7A-4) a first packet based on user plane data relating to one or more user equipment which is output by a first L1 PHY processing stage, the first packet including a proper subset of the user plane data which is to be transmitted over the air from a remote radio head to the one or more user equipment during a first time-slot symbol; to pass (S7A-5) the first packet to a second L1 PHY processing stage across a split fronthaul interface in a first time period having a duration corresponding to the duration of transmission of the first time-slot symbol; and to pass (S7A-6) one or more subsequent packets including the remainder of the user plane data across the split fronthaul interface in one or more corresponding successive time periods which are immediately subsequent to the first time period, wherein each of the time periods has a duration corresponding to the duration of transmission of a time-slot symbol in which at least one corresponding subsequent packet is to be transmitted over the air from the remote radio head to the one or more user equipment. at least one processor; and at least one memory including computer program code which, when executed by the at least one processor, causes the apparatus: to generate (S7A-4) a first packet based on user plane data relating to one or more user equipment which is output by a first L1 PHY processing stage, the first packet including a proper subset of the user plane data which is to be transmitted over the air from a remote radio head to the one or more user equipment during a first time-slot symbol; to pass (S7A-5) the first packet to a second L1 PHY processing stage across a split fronthaul interface in a first time period having a duration corresponding to the duration of transmission of the first time-slot symbol; and to pass (S7A-6) one or more subsequent packets including the remainder of the user plane data across the split fronthaul interface in one or more corresponding successive time periods which are immediately subsequent to the first time period, wherein each of the time periods has a duration corresponding to the duration of transmission of a time-slot symbol in which at least one corresponding subsequent packet is to be transmitted over the air from the remote radio head to the one or more user equipment. to generate (S7A-4) a first packet based on user plane data relating to one or more user equipment which is output by a first L1 PHY processing stage, the first packet including a proper subset of the user plane data which is to be transmitted over the air from a remote radio head to the one or more user equipment during a first time-slot symbol; to pass (S7A-5) the first packet to a second L1 PHY processing stage across a split fronthaul interface in a first time period having a duration corresponding to the duration of transmission of the first time-slot symbol; and to pass (S7A-6) one or more subsequent packets including the remainder of the user plane data across the split fronthaul interface in one or more corresponding successive time periods which are immediately subsequent to the first time period, wherein each of the time periods has a duration corresponding to the duration of transmission of a time-slot symbol in which at least one corresponding subsequent packet is to be transmitted over the air from the remote radio head to the one or more user equipment.