7.9 Simulcast of single-layer media

In some transmission scenarios (such as YouTube), a source can store several copies of the same media, althought variying the temporal resolution, spatial resolution and/or quality. In this situation, each media can be simultaneously broadcasted but in different channels. Thus, peers can switch between teams depending on the variations of the transmission bit-rate, the resolution requested by the user, etc. Notice that, time to perform a switch between channels depends on the buffering time, which depends on the buffer size, the transmission bit-rate and the GOP-rate, that depends on the GOP size and the picture-rate. In a switch, the end of the reception of the old channel should coincide with the beginning of the reception of the new channel, i.e, the buffering time should be predictable. Otherwise, the reception of both channels must be overlapped.