Abstract: A communications network configuration for delivery of multimedia services comprises a packet network to which a plurality of terminal devices are connected, a service provider network for providing multimedia services to the terminal devices, a virtual circuit switched network intermediate the packet and service provider networks, and a gateway distributed over the circuit switched network. The distributed gateway comprises a client application unit interfacing the circuit switched network to said packet network and a virtual channel interface unit interfacing the circuit switched network to the service provider network. The client application unit binds logical channels for a multimedia call to association tags for respective virtual channels of the circuit switched network and forwards said association tags to the virtual interfacing unit.

Abstract: A data sequence is transmitted from a transmitter to a receiver, being scrambled at the transmitter by adding a pseudo random sequence (PRS) thereto. At the receiver the received data is unscrambled by subtraction of the same PRS. The receiver PRS generator is synchronised to the transmitter PRS generator by means of samples conveyed from the transmitter to the receiver. The transmitter includes a PRS sample mapping block, the receiver includes a functionally complementary sample mapping block and the time of transmission of the conveyed samples is decoupled from the points in the PRS for which they were selected, the conveyed samples being skewed with respect to the PRS.

Abstract: A first (receiver), for example, pseudo random binary sequence (PRBS) generator (6) is synchronized with a second identical PRBS generator (2) at a tramsitter by adding a PRBS (u(x)) to a data stream (w(x)). The data stream includes a known value at periodic intervals. The received data is framed (5) and thus the position of the known data values determined. The received data is sampled at these positions to produce a sequence of samples (s(x)) comprising a sampled version of the transmitter PRBS. The phase of the transmitter generator (2) is determined for the samples and the phase of the receiver generator (6) adjusted to correspond. (FIG. 1). Implementation with sequence generators other than binary sequence generators are also discussed.