| 摘要 |
A global radio paging system is disclosed in which a plurality of radio frequency carriers having the same frequency are synchronously modulated in a plurality of base stations corresponding in number to the radio frequency carriers with the same digital paging signal and transmitted, respectively. A paging controller which receives paging calls through a public switched telephone network stores (PSTN) preliminarily the maximum value of a sum of a paging request signal transmission time in a transmission line and a time required to process the paging request signal in each of the base stations and a high precision time signal is produced on the basis of a reference signal from a GPS (Global Positioning System) satellite. In this paging controller, a transmission time assigning code is attached to the paging request signal. The transmission assigning code assigns a time instance which is delayed from a current time determined by the high precision time signal by the maximum value of the sum of the transmission time and the processing time as a transmission start time. On the other hand, in each of the base stations, a high precision time signal is produced on the basis of the reference time signal from the GPS satellite and the paging request signal supplied through the transmission line is processed on the basis of the high precision time signal to convert a format into the digital paging signal to thereby realize a synchronous modulation of the carriers. <IMAGE> |
