Below we present a figure expressing time slicing of three DVB-H terminals with different
data rates and a single DVB-T terminal (see Fig. 9.9). Time slicing is mandatory in DVB-H. The time
duration of data targeted for a user is called a burst. The time between bursts is defined as the OFF
time. This is the time that the terminal doesn??™t need to be listening to the DVB-H downlink and hence
can invoke power saving features.
One time-slicing burst includes one MPE-FEC frame; this creates a maximum size of approximately
2 Mb, generally representing 1??“5 sec of the media content.
One can easily see that if the ratio of the burst time to the OFF time is low, then significant power
saving is possible. In addition to reducing power consumption, time slicing can allow for seamless
handovers. This can be achieved by using the OFF time to monitor/measure neighboring cells on
other frequencies. In the absence of time slicing when a terminal would perform these neighbor cell
measurements, an interruption in service would occur. The combination of time slicing and reasonable
synchronization between DVB base stations can provide a seemingly nondisruptive reception of
data when handing off from one cell to another.
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