A system for reducing internal interference in a radio-frequency receiver includes providing a plurality of time slots within a frame where the receiver is configured to receive external RF signals during a receive time slot within the frame. More specifically, methods and systems for allowing individuals to post an invitation to for a meeting on an on-line network and for allowing one or more other individuals to accept such invitation. The data transmission module further includes: a usage status predicting unit that predicts, on the basis of the acquired usage status data of the detection time period, an idle timing at which no communication messages are flowing over the communication bus; and a data transmitting unit that transmits communication messages to the communication bus at the predicted idle timing. The unit arranged between the pulling-off drum and the opening device is formed by a pocket wheel or a pocket chain provided with revolving pockets for receiving the printed sheets which are supplied with their folds facing forwardly, and a conveying member arranged in front of the pockets. Different conditions can be specified for a given data field and each condition can be associated with a particular graphical indicator. The pixel-based representation is stored in a frame buffer and a video signal based on the contents of the frame buffer is provided to a video multiplexor.