| 摘要 |
<p>DIGITAL CONFERENCE CIRCUIT AND METHOD A digital conference circuit for a digital telephone switching network is provided, connected between a receive TDM (time division multiplex) bus carrying PCM (pulse code modulation) words to the conference circuit and a transmit TDM bus carrying PCM words from the conference circuit. A memory (storage) device stores the PCM words most recently received on the receive TDM bus and decision circuitry determines, for each conferee, which two PCM words, excluding the PCM word originating from that conferee, should be read from the memory device. The two PCM words so read are attenuated in a predetermined fashion, summed, and the resultant PCM sum applied to the transmit TDM bus during an appropriate timeslot. The decision circuit makes its decision based upon the largest average magnitude of each conferee's PCM words, received at the conference circuit, during the previous frames. In other words, for transmission on the transmit TDM bus to a given conferee, two PCM words are chosen from amongst the other conferees based upon the largest average magnitude of those conferee's PCM words.</p> |
