Handover in a mobile communication system having a multilayer radio coverage

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. The handover method of the invention is characterized in that in the method the service times are determined in the service area of the cell at the lower cell layer, a percentage P of the number of the service times restricted by a specific pre-set threshold service time R in a selected service time material is determined, a percentage of all the mobile stations (MS) within the service area of the cell to be examined is handed over to the target cell in the order of the relative moving speed, and the pre-set threshold service time R is adjusted to attain a desired traffic load level in the cell at the upper cell layer.

Dependencies are inferred from the claim text.