Abstract: In a transmitting node (3) in a transmission system, a plurality of source signals are multiplexed by a multiplexer (34) into a multiplex signal. The multiplex signal is transmitted to a receiving node (5) where it is demultiplexed in the source signals. The multiplex signal comprises a plurality of packets having a flag field, a length field, a connection ID field and a data field. The flag field can be present to enable the receiver to find the beginning of the packet or to carry non-urgent control signals. According to the present invention, the length of the flag field is dependent on the aggregate bitrate of the source signals, making it possible that more source signals can be transmitted over the transmission link under heavy traffic conditions.

Abstract: In a communication system the quality of transmission is improvied with an arrangment including a first node having compression processor that derives from a plurality of source signals a plurality of compressed source signals and a multiplexer for multiplexing said plurality of compressed source signals into a multiplex signal, the first node transmits the multiplex signal to a second node, the second node has a demultiplexer for demultiplexing the multiplex signal into the plurality of compressed source signals and decompression processor that derives the source signals from the compressed source signals. The compression processor is arranged for variable compression that compresses the source signals in dependence on an aggregate rate of the source signals that are transmitted and the decompression processor is arranged for variable decompression that decompresses the signals received from the demultiplexer to obtain the source signals.

Abstract: A supply circuit for a two-wire telecommunication line includes a voltage adjusting circuit section coupled between one of the wires and a first reference potential point and further includes a current source coupled between the second wire and a second reference potential point. A transistor in the voltage adjusting circuit section has a first main electrode coupled to the first wire, a second main electrode coupled to the first reference potential point, and a control electrode which is coupled to the first wire by way of a capacitor. In order for the supply circuit to meet strict requirements as to symmetry and demodulation, the control electrode is also coupled to the first reference potential point by way of a threshold voltage diode, which may be a zener diode. A voltage control circuit coupled to the threshold voltage diode forms a feedback loop for maintaining the line voltage at a selected value despite the presence of disturbing signals on the line.