TETRA OVER DVB-T/DTTV NETWORK
Digital Video Broadcasting—Terrestrial (DVB-T) is the DVB European-based con-
sortium standard for the broadcast transmission of digital terrestrial television that
was first published in 1997 and the first DVB-T broadcast was in the UK in 1998.
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CHAPTER 18
Evolution of TETRA
The DVB-T system transmits compressed digital audio, digital video and other data
in an MPEG transport stream, using coded orthogonal frequency-division multi-
plexing (COFDM or OFDM) modulation (ETSI, 2004-2006). Recently, there are
many efforts toward the use of the DVB-T infrastructure for emergency warning and
alert of the public in the view of disastrous events, as part of integrated Emergency
Warning Broadcast Systems (EWBS) (Azmi, 2011). EWBS usually use TV and ra-
dio broadcasting networks to alert people about impending disasters and enable them
to prepare for emergencies. The EWBS uses special warning or alert signals embed-
ded in TV and radio broadcasting signals to automatically switch on the receiver
equipment (if so equipped) in the home, and issue an emergency bulletin, alerting
people to an impending disaster such as a tsunami or an earthquake. Besides, at least
one special disaster emergency warning system standard for DVB-T which involves
a specific message flow architecture and transmitter and receiver standard have been
proposed (
Shogen, 2009
).
However, there are no available implementations of DVB-T-based systems that
are especially suited for Public Protection and Disaster Relief (PPDR) environments,
essentially being part of an integrated Emergency Response Broadcast System
(ERBS). Since TV broadcasting systems, including Digital TV (DTV) systems, are
widely available across rural and urban areas, and their operation and RF coverage
are not affected by the land type, the terrain morphology or the weather conditions,
the use of DVB-T based systems in terms of emerging ERBS systems would be
highly beneficial, especially considering: The higher video and audio transmission
rate of the DVB-T-based systems compared to their analog counterparts or previ-
ous digital TV implementations; The higher spectral efficiency compared to their
analogue counterparts; The advanced Forward Error Detection (FEC) capabilities,
which also provide a major capacity enhancement; and The improved signal robust-
ness against external influences such as the impact(s) caused by geography, weather
conditions and buildings/technical obstacles.
CONCLUSION
In general, it is important to provide a framework which will exploit additional net-
works (Mobile IP, Ad-Hoc Mobile Networks, and DVB-T) to support emergency
relief communications (which at this point and the foreseeable future is going to be
TETRA) and resource management during disasters in two aspects:
(i)
guaranteed communication
capabilities and services
among the response teams
and units
regardless of the location and level of crisis,
(ii)
communication
opportunities
between responders and general public, affected
people and their families
Involvement of families, citizens and social groups in rescue operations (millions of
eyes/agents over the Internet providing unstructured time critical information such
as possible locations of trapped people) has already illustrated its benefits during the
rescue operations after the recent major earthquake in Van, Turkey.
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