Figure 16.4 AMPS reverse communication band FDMA 30 kHz 3kHz 30 kHz 薄 Voice FM Analog 3kHz 30 kHz FM Voice Analog 3kHz 30 kHz FM .1 Voice Analog 10 kbps 30 kHz FSK control Analog 10 kbps 30 kHz FSK . control Analog 25-MHz band 16.12 16.12 Figure 16.4 AMPS reverse communication band