Patent ID: 7103105

Claim:
In an image communication apparatus for compressing video and audio data of an image and transmitting them, a packet data transmission protocol, in which one packet data frame comprises: header data containing information for separating video data and audio data and for synchronizing between a transmitter side and a receiver side; transmission and reception data size information based on a communication speed that varies based on a compression ratio of the video data; compressed audio data and video data; a control index representing information for indicating an additional operation from the group consisting of an image quality selection, an image retransmission, a privacy mode and a change in the size of video data and designation of conversion of image size data; and control data for notifying the receiver side of data relating to the additional operation, for representing information for requesting the compression ratio of the video data to be transmitted when the control index is controlled to select the quality of the transmitted image, and for representing a sequence number for requesting the image retransmission when the retransmission of the image data is requested in the control index.