Final Thesis


 DVB-Project: The emergence of the standards



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TejedorAlonso Marcos

2.2 DVB-Project: The emergence of the standards 
The DVB Project has used to promote standards and the transport for all systems is the MPEG2 transport 
stream. 
The standards are identify with the initials which identify the area. For example DVB-S is the specification for 
the first generation version of the digital satellite system and DVB-S2 for the second generation version of 
the DVB digital satellite system. 
At the beginning of the 1990s, due to the change that was happening in Europe and market priorities, the 
group decided to develop satellite and cable standards before terrestrial because they could develop more 
rapidly than terrestrial systems. 


TAMK University of Applied Sciences 
Escola Politécnica Superior de Castelldefels 
Marcos Tejedor Alonso 
11 (44) 
The 
DVB-S
(digital satellite broadcasting) was developed in 1993. This system was created using QPSK and 
it introduces channel coding and error protection, that are described at the specification. The first operator 
that offers these broadcast services in Europe was in 1995 by pay operator Canalplus in France. 
The 
DVB-C
standard (system for digital cable networks) was established in 1994. It is centred on the use of 
64 QAM. 
The 
DVB-T
system (digital terrestrial television) was more difficult to develop because of the noise
introduced by the environment and the bandwidth needed and the losses introduced by the multi-path. The 
system required to adapt its decoding depending of the signal. The key element is the use of OFDM. It can 
works in two modes: 

2K carriers + QAM modulation:
adequate when the receiver is in movement (take into account 
Doppler effect) 

8K carriers+ QAM:
this mode allow more multi-path protection. 
The first DVB-T broadcasts started in Sweden and in the UK around 1998. 
Also there are two systems for MMDS (Multi-channel Microwave Distribution Systems). The DVB-MC that 
operates at frequencies below 10 GHz, which is like DVB-C and systems that operates at radio frequencies 
above 10GHz known as DVB-MS (which is like DVB-MS). DVB-MT is also available. 

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