The master thesis overviews the hybrid TV systems that enable combining linear television
content and data via broadcast and broadband Internet channels using the HbbTV standard.
The signaling and transmission of hybrid applications are analyzed. New possibilities for
interactions are explored which are established through an interactive receiver after
launching the app. Approaches to using the interactive channel are shown, for the purpose
of providing accessibility to viewers with disabilities, for example the deaf. The system's
hybrid mode of operation opens up new possibilities for simpler and equitable access to
content and, consequently, greater e-inclusion.
First, the description of the hybrid television ecosystem's reference model is provided,
which enables full interactivity. The reference model's building blocks are explained. The
communication channels between the interactive service provider and the user are
described. Identified are the individual components of the interactive receiver, as well as
their functions for enabling of interactivity. In addition, three incomplete system
architectures are evaluated. Furthermore, the mechanisms for multiplexing of interactive
application data with other A/V components are described. An explanation is provided of the
data transmission over MPEG-2 system transport layer. This is followed by the description of
the receiver's processes at the transport stream reception. The description includes a step
by step explanation of synchronization from line over packet to data structure. Based on
PSI/SI tables, mechanisms are explained for checking and recognizing of hybrid content
signalization. A real case of HbbTV signaling is analyzed using the capture from the digital
terrestrial transmission network. Thereafter, different multiplexing methods are overviewed
for assuring additional free capacity for hybrid application transport in the existing networks.
In order to explore the possibilities for starting interactive services on the Slovene DVB
networks for assuring accessibility for persons with special needs, as for example the deaf,
an overview of the current situation of multiplexes MUXA and MUXC is provided. The
proposed multiplexing philosophy is evaluated. Chapter 6 includes an overview of the
problems and challenges related to the inclusion of the disabled persons. The importance of
Zagotavljanje dostopnosti do prilagojenih vsebin na TV za uporabnike s senzorno oviranostjo
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ICT in accessibility is emphasised, especially taking into account new technologies such as
HbbTV, bringing new accessibility possibilities and better e-inclusion.
The last part of the thesis includes a description of the real demonstrational system,
providing a possibility of automated usage of the interactive channel for dynamic triggering
of the linear A/V streams, through which the accessibility is provided to the selected group
of users with special needs. The system is easy to control. After the first setup the
automated mechanism works by itself, but under the user' control, that is, by a simple click
on a remote control's button.
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