| 摘要 |
Speech signals and data signals are transmitted between a mobile phone 1 and a base station 4 on the same channel, with the speech signals and data signals each being transmitted at half the full bit rate of the channel. The half bit rate speech and half bit rate data signals may be interlaced in a half time slot, the time slot being divided into two half slots by a learning sequence (see fig. 3). The data may be transmitted in packet mode, with the packets being stored in a buffer memory 34 prior to transmission. The mobile phone may include a speech encoder-decoder 10 which is operable at half bit rate, and transmission of the speech signals may be downgraded from full bit rate to half bit rate. The base station may include means 18 for synchronising the speech and data signals. The method allows a mobile telephone to operate simultaneously in circuit mode and packet mode. |
