Telephone conference system - adds samples of selected subscriber channels and retransmits and distributes sum to subscribers as second order digital signal

摘要

The conference telephone system connected to a connection network through multiplexed bidirectional digital channels sums the amplitudes of samples of the subscriber digital channels, which are to be included in a conference, as a function of an address of a read-write memory which authorises only the selected subscribers. The sum is retransmitted in the form of a second order digital signal to the connection network which distributes the signal to the selected subscribers. The word binary elements, previously parallel, are arranged in a memory and the amplitudes of the words are extracted during a set time interval for summing. The result is stored in a buffer memory if authorised by the exploitation memory.