| 摘要 |
PROBLEM TO BE SOLVED: To provide a PHS telephone system in which the decoder side can quickly establish synchronization tandem with the encoder side in the case of recovery from a transmission path error generated during a telephone call.SOLUTION: For example, when an error occurs in a downlink transmission path from a cell station to a PHS terminal ("Yes" in step S2) in an information channel (TCH) communication state in which voice data is transmitted/received using a TCH in communication physical slots (step S1), the cell station on the transmission side of the downlink transmission path having the error shifts to a second information channel (TCH2) communication state in which transmission operation using recovery processing communication physical slots as communication physical slots for performing transmission to the PHS terminal is performed (step S4) until recovery from the error in the downlink transmission path is implemented, where the recovery processing communication physical slots include a quantization differential signal region for setting a current quantization differential signal in an encoder and a TCH2 for setting an ADPCM signal obtained by encoding voice data, instead of the TCH. |
