1. A method for assigning geographically oriented units of a first hierarchical level of a radio communication system to geographically oriented units of at least one second hierarchical level that is higher than the first hierarchical level, which comprises: setting up functions that specify, as a function of a number of subscribers of a radio communication system, a size of a load, that is selected from the group consisting of a radio load and a switching load, and that is caused by a geographically oriented unit of a first hierarchical level at a node of the radio communication system; setting up a formula which, using the functions, permits a size of a processing load occurring at each node, in a case of a given assignment of geographically oriented units of the first hierarchical level to geographically oriented units of the second hierarchical level, to be calculated for a given number of the subscribers; and using the formula to select an assignment that permits a greatest possible growth in a number of subscribers of the radio communication system without a processing load at a geographically oriented unit of the second hierarchical level exceeding resources of the geographically oriented unit of the second hierarchical level.