IEEE

1. Second Screen Prototype for Broadcasted Digital TV
Users in ISDB-Tb Standard
Cláudio Henrique Albuquerque Rodrigues
Eliel de Lima Reis
Faculdade FUCAPI
Manaus, Brasil
claudio.albuquerque@fucapi.br / eliel.lima@fucapi.br
Vicente Ferreira de Lucena Jr.
PPGEE - Programa de Pós Graduação Engenharia Elétrica
UFAM - Universidade Federal do Amazonas
Manaus, Brasil
vicente@ufam.edu.br
Abstract — This paper describes a proposal for a Second
Screen solution designed for the Brazilian Digital Television
System - SBTVD. Our solution allows users to access and to
interact with additional content related to the broadcasted
program through the internet (synchronously with the content
displayed on digital TV screen). The proposed architecture
makes use of a specific protocol, the Transmission Transport
Stream. It will carry the information needed to allow receivers of
digital TV to communicate with multiple Second Screen devices
relying nearby (such as smartphones, tablets, and PDAs). These
devices must be running a dedicated software application in
order to connect to the World Wide Web accessing the desired
additional information. The motivation for this work is to bring
to users with limited resources, the ones watching broadcasted
over the air programs, the opportunity to benefit from the
Second Screen technology. These users, in possession of our
Second Screen mobile application will be able to access additional
information synchronized with the programs live broadcasted,
opening new opportunities for broadcaster and users.
Keywords – Second Screen; Digital TV; Mobile device.
INTRODUCTION
Along with the evolution of mobile devices and the change
from analogue to digital TV system, many new challenges
emerged. In addition to interactivity, that directly reflects the
availability of flexible content, came the perception that what is
going to be watched depends more than ever on TV viewer
decision. The Second Screen is one of these new technologies
created to offer the viewers the opportunity to interact with the
content displayed on their TV screens. It makes use of
dedicated software applications, designed for individual
devices, to connect the users to additional information about
the actual TV program content [1].
Among the advantages provided by the Second Screen,
there is a possibility for the viewers to interact with the
broadcasted content in a very particular way. With the
computational power of modern consumer electronics
products, small private devices, like cell phones or other
mobile devices, are capable to carry on such tasks without
disturbing the privacy of others viewers sharing one TV set on
a same room. Allowing the interaction of one or more viewers
watching the same content simultaneously, displaying
additional information in a very private way through different
mobile devices, offers new possibilities of interaction,
improving the users’ experience.
This paper proposes a second screen approach for broadcast
content providers, in a suitable setting for SBTVD, also known
as ISDB-Tb (Integrated Services Digital Broadcasting
Terrestrial Brazil) [2]. The changes in the signal generated by
the content providers to include Second Screen options in the
BTS will be described. A scenario that enables its detection,
synchronization, and use of this technology will be explained
by the end user point of view. This mechanism should work
automatically for end viewers at home.
SECOND SCREEN FOR ISDB-TB
In order to validate the proposal, and evaluate the results of
the Second Screen system between mobile devices and ISDB-
Tb digital signal receivers, a working prototype of the proposed
system was developed. The prototype consists of two parts. 1 -
The simulation of a digital TV receiver embedded in the form
of a computer application, which receives, decodes, and
displays content generated by broadcasters (containing
information on the availability, as well as, the identification of
the Second Screen information source). 2 - An application for
mobile devices, developed for smartphones and tablets, capable
to identify the embedded Second Screen information and
present the interactive content synchronized with the content
displayed on the first screen.
The proposed solution provides interaction with digital
television content through its three main categories [3]: Local
Interactivity (the reception and consumption of information in
Second Screen); Interactivity without dedicated return channel
(interaction with the information arranged in Second Screen via
internet connection); and Interaction with dedicated return
channel (using the Second Screen as an extension of digital
television content already present on the target device
functionality).
Through the interconnection of multiple different devices
on a local network, it becomes possible to add new features to
digital signal receivers. For example, the ability to acquire
characteristics of ubiquitous and pervasive computing [3]. This
characteristic may be acquired by the understanding of specific
information by the mobile devices housing the Second Screen
application. These new functionalities may respect the notions
of context awareness, i.e. they should start running without
requiring users’ intervention or the manual addition of new
components in the target devices.
This research was supported by SAMSUNG, CAPES, FAPEAM, and
CNPq.
2014 IEEE 3rd Global Conference on Consumer Electronics (GCCE)
978-1-4799-05145-1/14/$31.00 ©2014 IEEE 266

2. The scenario for implementing this proposal made use of
the architecture shown in Fig. 1.
Fig. 1. Scenario for the proposed Second Screen system.
Main components involved in the system are: the
broadcasters transmitting audio/video and data information;
one or multiple Second Screen content providers, one or
multiple Second Screen content consumers, represented by the
digital TV set, the applications running on the mobile devices,
and a wireless local network that interconnect these devices
through TCP / IP protocol.
On the signal content generation side, the encoder will
encapsulate audio and video data into the TS packets
multiplexed by ISDB-Tb MUX. The headers of these TS
packets contain information about data decoding, packet
identification - PID (Packet ID - Packet IDentifier), and
synchronization. All these fields are standardized by ISO/IEC
13818-1 [4]. There is also information that is unique in each
country or even for each content generator. This information is
transmitted in structured tables as shown in Fig. 2, which in
turn is also carried as payload of the TS packet.
Fig. 2. ISO/IEC 13818-1 and ITU-T Recommendation H.222.0.
In the proposed Second Screen approach it is necessary to
include information about the content provider in the AIT
table. It’s identification in the TS, the PID, is informed by the
PMT (Program Map Table), i.e., defined by the table_id field.
The other fields should be configured with values set by the
standard ABNT NBR 15603 [5], except for the private data
field, also called descriptor, which will be used by the Second
Screen application developed for mobile devices. This
descriptor, called IBB Application, must obey the syntax
specified by ITU-T Recommendations J.205 and ITU-T J206,
as shown in Fig. 3.
Fig. 3. Syntax standardized by ITU-T Recommendations J.205 and J206.
Code field is a binary code to execute the descriptor.
Resources is the field of information on the application, in
accordance with ISO/IEC 8859-15. Meta-data field consists of
information associated with the application. Control is a field
used to provide the controls of the available application.
Finally, User settings field contains some other configuration
parameters provided by the broadcast stations.
The digital signal receiver is responsible for decoding the
signal through the BTS and signalizing the network about the
existence of interactive content available in passive mode. The
ISDB-Tb Receiver has extension libraries, capable to
communicate, through TCP and UDP. The LuaSocket [6]
library is used to implement the communication interface and
can be easily adapted and included in the player.
Communication interface is part of the proposal for the
Second Screen system. It was implemented through an
application running in the digital TV receivers that is able to
understand and inform the associated mobile devices about the
existence of such options. Another application on the mobile
devices side is able to decode the information coming from the
TV receivers into a meaningful internet address.
CONCLUSION
This proposal was created aiming at ease of use of the end
customer, i.e., without the need of specific knowledge to
configure the involved devices. The only action required is to
install the developed application on the mobile device and on
the digital TV receiver. Broadcasters are required to change the
BTS, including information about the Second Screen source,
and to create a content provider to be accessed by the mobile
device through the internet. It can be used in any standard, as
long as it allows the signalization of the availability of Second
Screen through the BTS.
REFERENCES
[1] P. Cesar, D.C.A Bulterman, and A. J. Jansen, "Usages of the secondary
screen in an interactive television environment: Control, enrich, share,
and transfer television content." Changing television environments.
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[2] L.C.P. Costa, "A technical analysis of digital television broadcasting in
Brazil." Broadband Multimedia Systems and Broadcasting (BMSB),
2013 IEEE Int. Symposium on. IEEE, 2013.
[3] W. K. Edwards, "Discovery systems in ubiquitous computing."
Pervasive Computing, IEEE 5.2 (2006): 70-77.
[4] Recommendation ITU-T. "H. 222.0| ISO/IEC 13818-1." Information
Technology—Generic Coding of Moving Pictures and Associated Audio
Information: Systems, ITU-T/ISO/IEC (2007).
[5] NBR 15603-1, ABNT. "ABNT NBR 15603-1, Multiplexação e serviços
de informação (SI) Parte 1: SI do sistema de radiodifusão." ABNT, 1.
ed. (2007).
[6] D, Tuler, “Lua Socket". Available in: http://luasocket.luaforge.net.
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