| 摘要 |
A video telephone system for performing video telephony over a network (N) having at least one transmission channel (7) with associated network resources (TBW) and at least one control channel (10) is described. The video telephone system comprises a transmitter terminal (1) for transmitting at least one video data stream (s3) and first control data (ctrl msg) corresponding to the at least one video data stream (s3) over the at least one transmission channel (7), and a receiver terminal (2) for receiving at least one video stream (s4) and first control data (ctrl msg) transmitted over the transmission channel (7) and for transmitting second control data (ACK) relating to video characteristics of the transmission channel (7) to the transmitter terminal (1) in accordance with the received at least one video stream (s4) and/or first control data (ctrl msg). Furthermore, a video characteristic-adapting unit (6, 5) is provided for adapting the video characteristics of at least one video data stream and the first control data (ctrl msg) in the transmitter (1) in accordance with the second control data (ACK) received by the transmitter terminal (1) over the control channel (10), and for providing a bandwidth margin (BWM) by adapting the video characteristics of at least one video data stream and the first control data (ctrl msg) in such a way that the bandwidth (VD) of the at least one video data stream (s3), the bandwidth (TC) for the first control data (ctrl msg) and the bandwidth margin (BWM) correspond to the associated network resource (TBW) of the transmission channel (7). |
