| 摘要 |
PROBLEM TO BE SOLVED: To transmit only a prescribed channel to a remote place outside a cell without increasing the size of a base station by arranging repeaters provided with filters which pass only a prescribed channel in the cell of the base station. SOLUTION: Repeaters 201-204 are arranged along the circumference of a cell 206 that the radio wave of a base station 205 forms. The repeaters 201-204 are provided with filters which pass only a prescribed signal in signals received by directional antennas. Only a frequency f1 is made to pass through. The directional antennas on the reception side of the respective repeaters 201-204 are set in the direction of the base station 205. Even if the base station 205 uses frequencies f1, f2 and f3, the repeaters 201-204 pass and amplify only the frequency f1. Thus, only the signal of the frequency f1 is transmitted to a remote place and the radio areas 207-210 of the frequency f1 are formed on the outer side of the cell 206. The radio areas may be formed around the outside of the cell 206 by using an increased number of repeaters. |
