A method for terrestrial data transmission between aircrafts and external networks, the method comprising: establishing a first broadband over power line "BPL" communication channel and a second BPL communication channel through an electrical power cable connected to an aircraft and a gate, the power cable comprising a first conductor and a second conductor, the first BPL communication channel established through the first conductor, the second BPL communication channel established through the second conductor; generating a first transmission packet from a first data domain and a second transmission packet from a second data domain using a channel management unit; sending the first transmission packet for transmission through the first BPL communication channel; and sending the second transmission packet for transmission through the second BPL communication channel, characterised in that the channel management unit generates the first transmission packet and the second transmission packet based on one or more factors selected from the group consisting of: duration of the power cable connection, security status of each of the first data domain and the second data domain, security of each of the first BPL communication channel and the second BPL communication channel, transmission priority of each of the first data domain and the second data domain, transmission rate of each of the first BPL communication channel and the second BPL communication channel, and data amount in each of the first data domain and the second data domain. establishing a first broadband over power line "BPL" communication channel and a second BPL communication channel through an electrical power cable connected to an aircraft and a gate, the power cable comprising a first conductor and a second conductor, the first BPL communication channel established through the first conductor, the second BPL communication channel established through the second conductor; generating a first transmission packet from a first data domain and a second transmission packet from a second data domain using a channel management unit; sending the first transmission packet for transmission through the first BPL communication channel; and sending the second transmission packet for transmission through the second BPL communication channel, characterised in that the channel management unit generates the first transmission packet and the second transmission packet based on one or more factors selected from the group consisting of: duration of the power cable connection, security status of each of the first data domain and the second data domain, security of each of the first BPL communication channel and the second BPL communication channel, transmission priority of each of the first data domain and the second data domain, transmission rate of each of the first BPL communication channel and the second BPL communication channel, and data amount in each of the first data domain and the second data domain. duration of the power cable connection, security status of each of the first data domain and the second data domain, security of each of the first BPL communication channel and the second BPL communication channel, transmission priority of each of the first data domain and the second data domain, transmission rate of each of the first BPL communication channel and the second BPL communication channel, and