A discontinuous transmission bit processing method for a multirate modulation scheme is provided. The hosts store for each multicast group an included source record and an excluded source record, and the network interfaces of the hosts send to the router a message containing information about the included source record and information about the excluded source record. Visual representations from the set of visual representations of captions are sent with the video information over a network to the user device where text for the captions has been pre-rendered in the sent visual representations before sending of the visual representations to the user device. The detector is oriented, in relation to the incident radiation, so that the radiation preferably enters sideways between a first and a second essentially parallel plate, between which the electrical field is created.