Cellular mobile communication system

摘要

The present invention relates to a cellular mobile communication system comprising a number of radio base stations (BS) and a number of mobile stations (MS) wherein the system comprises a number of cells which are arranged in at least two different layers of preference. Connections carried on the communications system can be handed over from one cell to another and at least one signal parameter is measured or monitored. At least one threshold is given at least for each cell in the lower layers or at least one signal parameter. The system furthermore comprises means for deciding on and controlling handover decisions comprising a priority ranking arrangement based on a number of criteria of which one is based on a comparison between a monitored value (Io) of a signal parameter with the threshold value (Io) of the serving cell and a second one is based on a comparison of the monitored value of a signal parameter (Ii) with the corresponding threshold value (Ii) for a neighbour cell wherein handovers are governed by the priority ranking arrangement so that a systematic passing also up as well as down between layers is obtained.