One disclosure of the present specification provides a telematics communication unit (TCU) mounted in a vehicle. The TCU may comprise: a memory; a plurality of transmission/reception units including one or more antennas; and a processor for controlling the plurality of transmission/reception units. The processor may perform the steps of: collecting service requirements for one or more electronic devices in the vehicle, and then transmitting the collected service requirements to a server via a base station; receiving downlink data from the server through the base station; determining whether a data transmission rate according to the service requirements for one or more electronic devices in the vehicle can be supported at a transmission rate through available frequency channels of an antenna beam; and transferring the downlink data received from the server to the one or more electronic devices in the vehicle through the antenna beam according to the determination.