First deals with handoff measurements
and execution. In the time slicing aspect this is a period of time denoted in the DVB-H standard
as OFF time. However, note the receiver is not completely turned off. The receiver must decode the
3G AND BEYOND DISCUSSION 487
SFN
@f1
SFN
@f2
SFN
@f3
MPEG-2 Data
MPEG-2 Data
MPEG-2 Data
(MPE-FEC)
MUX
Encapsulation
IP
Backbone
FIGURE 9.10 DVB-T and DVB-H network scenario.
data received over the DVB-H air interface and deliver the content to the specific media player. Certain
sections of the terminal can be powered down for a reduction in power consumption, but the user must
see a continuous data stream at the application end. Moreover, if neighboring cells need to be monitored
to access the need for a handoff, then this power down benefit is lost during those periods of time. For
this case, in addition to decoding the burst of data previously received the terminal must switch the
frequency band to make certain measurements. Lastly, if a handoff must occur and the base stations are
not reasonably time aligned then a disruption in service can occur. This disruption is somewhat dependent
on the terminal capability (receiver architecture, size of memory, processor speed, and so on) and
should be minimized in order to deliver a gratifying experience to the end user [28].
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