obile TV standard DVB-H addresses all of these issues with some ingenious techniques. More- over, DVB-H is based on the digital television standard DVB-T which has capabilities for robust signal transmission. Therefore DVB-H is downward compatible with DVB-T and provides additional elements for enhancing the system robustness. The enhancements include several aspects: signal modulation, error protection and time slicing. Signal modulation in DVB-T transmission is based on COFDM (coded orthogonal frequency division multiplex) and uses about 2000 or 8000 carrier frequencies on which transmitted streams are overlaid. This provides robust reception in vehicles and in environments with radio wave reflections. The DVB-H standard foresees, in addition to these two types of modulation, the so-called 4k modulation mode, which uses about 4000 carriers in order to provide a good compromise between the 2k mode, which can support fast moving terminals but smaller transmitter coverage, and the 8k mode, which maximises cell size but can not support fast moving terminals, showing higher sensitivity to Doppler effects. Mobile environment reception with small antennas is exceedingly prone to packet loss. To deal with this problem, packet error correction has been introduced in DVB-H as an option, in order to guarantee improved performances in difficult reception conditions. The final challenge is a limited battery power supply, precluding the use of TV over prolonged time periods. This is a serious problem since both the TV tuner part and the demodulator consume substantial amounts of power. To deal with this, the DVB standard uses so-called time slicing. The TV streams are sent to a receiver at higher speeds than normal and are buffered at the terminal. It is then possible to load the receiver buffer and switch the tuner and demodulator off until it is empty. For example, sending data four times faster than the nominal speed allows the receiving part to be kept switched off for 75 % of the time, extending the batter of life by th