Abstract: The idea of the invention is to allocate channels within a predetermined group of cells with a dynamic channel allocation method and to equalize interference caused to the cell group by connections outside the cell group e.g. through frequency or time slot hopping. Cell groups may be superimposed and they may be formed e.g. by the cells of an office system or a broad-coverage mobile communications system, by the cells of a mobile communications network of two different operators, by the cells of a network according to two different systems or by the cells of a network operated by one operator. If the cell groups are formed of cells in one network, a suitable size may be chosen for the cell group so that the computing and signalling load required by centralized dynamic channel allocation in the cell group will remain easily controllable.

Abstract: In channel allocation, the objective is to allocate channels to desired connections using the available frequency spectrum as effectively as possible so that the connections will not cause excessive interference to each other. This invention presents a method based on time blocking of transmission in connections using different transmission powers, in order further to improve the allocation of channels.

Abstract: Radio frequencies of a base station in a cellular network are chosen adaptively so that when choosing the uplink frequency the base station measure at all frequencies or at some frequencies of the reception band used in the system what is the total power of the signal received at the frequency in question. The frequency at which the lowest power is received is chosen as uplink frequency. When choosing the downlink frequency, a tuning signal is transmitted at all frequencies or at some frequencies of the transmission band. Mobiles located in areas of other cells and operating at the same frequency experience the effect of the tuning signal as an interference. The base station is tuned to use that downlink frequency at which the interference caused by itself to other traffic is sufficiently low.

Abstract: When a dynamic channel allocation method based on monitoring of signal levels is used for channel allocation, the results of signal level measurements must be averaged in order to achieve a sufficient reliability. Averaging causes a delay in measurement results, for which reason such a channel may be allocated the interference level of which has just changed e.g. because another connection has been set up which functions nearby on the same channel. According to the invention, allocation of a channel causing excessive interference with a connection already set up is limited.

Abstract: The present invention relates to a handover method in a mobile communication system having a multilayer radio coverage, the system comprising at least one microcell (1, 2, 3) and at least one macrocell (M). The coverage area of the microcell (1, 2, 3) is at least mainly within the coverage area of the macrocell (M), the microcell layer forming a lower cell layer and the macrocell layer forming a higher cell layer. A cell to be examined and a target cell are located at different cell layers in the mobile communication system. In the method, relative moving speeds of mobile stations (MS) in the service area of a cell at the lower cell layer are determined and a traffic load in a cell at the higher cell layer is monitored.

Abstract: The invention relates to a method of setting a load goal in a radio system. In the method a total signal strength (41) and a load result (44) are first formed, the load result being formed as an interrelationship between signal-to-interference ratio, bandwidth and data transmission rate. Then the total signal strength (41) change is compared with the load result (44) change, and such a load result (22) is searched for, the higher load results (44) of which provide a load result change lower than a predetermined threshold value in relation to the total signal (41) change, and said load result (22) is selected as a load goal.

Abstract: A radio system and a method for controlling transmitting power in the radio system, the radio system being composed of at least one base station communicating with one or more subscriber terminals located within a coverage area. The transmitting power of each subscriber terminal is controlled stepwise by power control commands and the step size of a change in transmitting power is adjusted separately for each connection. In order to achieve an accurate and fast power control, the step size is adjusted on the basis of several received successive power control commands by calculating, from the power control commands, the number of two successive commands in different directions in proportion to the number of commands examined, the calculated proportion is compared to a reference value and the step size is adjusted on the basis of that comparison.