Abstract: A method of controlling data transfer in a data transmission system which includes a plurality of video and/or audio data sources, a single transmitter operable to transmit data from the data sources over at least one transmission channel, a plurality of client receivers operable to receive transmitted data, the method comprising estimating available channel capacity for each client receiver, using parameters relating to the at least one transmission channel, and using information from the transmitter and receiver, and using information relating to queuing of data between the data sources and the transmitter; determining a target bit transmit rate for each client receiver in dependence upon the estimated channel capacity, a quality parameter, and an activity parameter for the client receiver concerned; and controlling the data sources and transmitter in dependence upon the determined bit transmit rate.

Abstract: The invention relates to apparatus and method which can be used to receive broadcast digital data. The apparatus and method are provided at one or more receiving locations and is connected to one or more broadcast data receivers at each location. The apparatus is capable of receiving and processing data in linear and/or circular polarity formats and the operating condition of the same can be altered in response to a command signal broadcast to the receiving locations prior to the transmission of data in a new format such as to the change in the operating condition of the apparatus to receive and process linear as well as the previously broadcast circular polarity format data.

Abstract: The invention relates to a system, apparatus and method for the distribution of digital data signals, which are received at a receiving means, to be sent to a plurality of locations downstream therefrom, in an efficient manner. The received data is received in a first format such as an RF format with a plurality of different components and is then changed in format, in one embodiment to an optical format. The data path is also split to allow a plurality of data paths to be defined which allow the data to be transmitted along the plurality of data paths to each of the downstream locations.