Method for operating a mobile radio telephone system, mobile radio telephone system, mobile station and device for determining a sub-group of adjacent radio cells in a mobile radio telephone system

A method for operating a mobile radio system with a first group of adjacent radio cells and a second group of adjacent radio cells, the first and second groups of radio cells being overlaid on each other, comprising:

• measuring signal quality from a mobile station, which is operating at a current position in a first radio cell of the first group, to other radio cells of the first group that are adjacent to the first cell;
• determining which of other radio cells of the first group has the best signal quality for the current position of the mobile station;
• identifying a sub-group of radio cells from the second group based on which radio cell of the first group has the best signal quality;
• and
• measuring signal quality from the mobile station to the sub-group of radio cells from the second group but not to other radio cells of the second group that are not included in the subgroup.

A device to determine a sub-group of adjacent radio cells in a mobile radio system with a first group of adjacent radio cells and a second group of adjacent radio cells, the first and second groups of radio cells being overlaid on each other, comprising:

• a first measurement unit to measure signal quality from a mobile station, which is operating at a current position in a first radio cell of the first group, to other radio cells of the first group that are adjacent to the first cell;
• a determination unit to determine which of other radio cells of the first group has the best signal quality for the current position of the mobile station;
• an identification unit to identify a sub-group of radio cells from the second group based on which radio cell of the first group has the best signal quality;
• and
• a second measurement unit to measure signal quality from the mobile station to the sub-group of radio cells from the second group but not to other radio cells of the second group that are not included in the subgroup.