A method for securing the operation of a base station having a radio coverage area divided into at least two sectors, and a base station having antennas, with combiners and branching units, and at least one channel unit for each sector, which allow the base station to establish a radio connection with active radio transceivers currently located in the base station sectors. In the method, the base station is provided with an additional channel unit the traffic capacity of which is selectably switchable to one of the base station sectors. To secure the operation of the base station when one of the channel units fails, the operation of the channel units of the base station is monitored. When one of the channel units fails, the additional channel unit is connected to the antenna of the sector of the failed channel unit by a switch, which connects the antenna attachments of the additional channel unit to the antenna of one sector at a time.