Dual channel dual speed FM subcarrier paging system

摘要

The effective transmission range of a wireless paging system is varied by changing the transmission data rate. The transmission data rate is lowered in regions with sparse transmitter coverage to increase the effective transmission range of the transmitter. The dual transmission data rates are transmitted either on separate subcarriers on the same FM channel, on the same subcarrier of different FM channels or alternatively on different subcarriers of different FM channels. In a region with dense transmission coverage, the receiver decodes transmission messages at the faster transmission data rate. In regions with sparce transmission coverage, the receiver decodes messages at the slower transmission data rate.