Abstract: A circuit arrangement is disclosed for individual subscribers in a telecommunication set up. The circuit arrangement converts analog signals into digital signals and digital signals into analog signals. When operated in a conference connection, summation signals are received by a subscriber which contain the subscriber's own share. Output digital signals from the subscriber are stored and converted into an analog value and are then subtracted from the received summation signal converted into an analog value.

Abstract: A circuit arrangement is disclosed for converting digital signals into analog signals and analog signals into digital signals. The circuit arrangement is used as a conference set for use by individual subscribers on a multiplex line. Digital signals of all subscribers are consecutively converted into analog signals and an analog summation signal is formed therefrom. This summation signal is again converted back into a digital signal and can be multiply transmitted as such. Alternatively, a number n of circuit arrangements are provided for a maximum number n of subscribers. Each of the circuit arrangements converts digital signals of n-1 conference subscribers (excluding an allocated subscriber) into analog signals and forms an analog summation signal therefrom. This analog summation signal is converted back into a digital signal which is transmitted in a time slot allocated to the allocated conference subscriber to which the circuit arrangement is allocated.