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: 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: This invention relates to a method and system of transmitting video data and multimedia data to a plurality of client radio receivers over an air interface using an adaptive encoding/transcoding scheme and updating the adaptive encoding/transcoding scheme in dependence upon received feedback data. A system and method is also described that includes estimating channel states and distortion levels for a plurality of transmission modes, then selecting that transmission mode for subsequent data transmission that has the lowest distortion level. Control data items can also be extracted from the first data stream to produce a multimedia data stream and a control data stream and the multimedia data stream is transmitted over a first channel; and the control data stream is transmitted over a second channel.