| 摘要 |
A telecommunications data transmission system (1) for communicating between a client's PC (2) and a server (3) of an internet service provider comprises transmission between a PCM codec modem (5) of the server (3) and a liner codec modem (6) of the PC (2). Data received by the PCM modem (5) for the server (3) is passed through a first receive data buffern (10) to the server (3), while a second receive data buffer (11) passes data from the linear modem (6) to the PC (2). First and second transmit data buffers (8, 9) hold data to be transmitted by the PCM modem (5) and the linear modem (6), respectively. First and second microprocessors (14, 15) control the data transmission rates of the modems (5, 6), respectively. During handshaking first and second data transmission rates are selected by the microprocessor (14, 15) for the PCM modem (5) and for the linear modem (6) for minimising echo in the transmission. The modem (5, 6) having to transmit the highest volume of data is selectively operated at its respective high data transmission rates, while the other of two modems (5, 6) is operated at its low data transmission rate. The microprocessors (14, 15) control the modems (5, 6) to avoid the two modems (5, 6) operating simultaneously at their respective high data transmission rates. |
