| 摘要 |
In a mobile radio communication system, a plurality of sector antennas (32d) are used whose half-power beam widths are different from (smaller than) the basically-used normal sector antennas (32a,31c) so as to cover the same areas (42d,42a,41c) in an overlapping manner. A radio base station (11;12) covers a plurality of cells using the respective sector antennas. Some of the radio base stations (12) cover a partial area overlapping a normal sector cell with a narrow sector cell using one of the sector antennae with small half-power width. Each radio base station has a predetermined constant according to the half-power beam width. When a radio terminal (21,22) requests a call origination, the corresponding radio base station selects the antenna for which the sum of the received level of a signal sent from the radio terminal and the constant is the largest. <IMAGE> |
