Television and the Web
Convergence in the HomeNet Environment
Position Paper for the W3C Workshop in Sophia Antipolis, France, 29/30
June 1998
Klaus Hofrichter, GMD FOKUS (hofrichter@fokus.gmd.de)
Hans Werner Bitzer, Deutsche Telekom Berkom GmbH (bitzer@berkom.de)
Keywords: HomeNet, Home Automation, WWW, DVB, DAVIC
Abstract
The HomeNet environment is a natural place to develop applications which
take advantage of the various communication technologies. HomeNet applications
comprise access networks such as analog and digital TV, ISDN and possible
inhouse networks such as IEEE 1394 FireWire or home-automation busses (EIB,
LON). This article describes the integration of various networks, distribution
methods and presentation technologies following a HomeNet scenario. The
scenario covers under a single user interface access to broadcast MPEG-2
video, DVB-SI, DVB Object Caroussel, VideoPhone, WWW, and other data
services. This paper is based on a prototype developed by Deutsche Telekom
Berkom.
Introduction
"Convergence" is one of the typically vague buzz-words of the current time.
Nevertheless, the word is best suited to describe the approach taken by
the prototype presented here, which aims to develop an integrated solution
to access a variety of services, networks and technologies under a single
user interface. This prototype is part of ongoing development work on a
single navigation concept for SmartHomes, that adapts to a variety of end
systems. However, the TV set plays a prominent role. It is not the primary
aim to develop new technologies. Instead, the combination of existing tools,
approaches and applications allows to exploit already installed devices
and networks and to create new and sometimes suprising applications. The
developments presented here are closely linked to the discussions on Home
Networks (physical layers an well as application aspects) and APIs within
DAVIC and DVB (DVB-MHP, -IHDN).
A HomeNet can be seen as a unified access framework for all kinds
of devices, services and applications in a residential environment, including
the SOHO (Small Office, Home Office) components. The HomeNet comprises
devices such as a telephone, a TV set, a PC, in-house cameras, heating
control, home automation, and various consumer electronics (CD-Player,
VCR, DVD, ...). The components are connected via various networks, and
receive data from external sources, e.g. analogue and digital TV, DVB data
caroussel, or WWW/Internet via ISDN. Due to the variety of devices and
services a plethora of application and content formats is to be handled.
This includes TV-oriented formats and Internet formats (including VRML),
but also future formats such as MPEG-4.
The prototype of a SmartHome Navigator for the media-rich graphical
user interface utilises in the scenario described below the TV screen
to watch a digital TV program, to access the WWW to load on-line
information about the movies, in order to take advantage of DVB-SI to display
an electronic program guide (EPG) and to use an ISDN videophone system
to communicate. The Internet based online services and Digital Video Broadcast
services are seamless integrated under this umbrella. Hence, "Convergence"
of broadcast services, interactive services (e.g. Internet) and communicative
and inhouse services is already under way.
A SmartHome Scenario
The scenario descibed here is build around a talkshow in the television.
The user has several opportunities to watch or even to take part in the
talkshow. The SmartHome Navigator provides the user interface to access
the required services. This scenario covers not all implemented functionality
of the Prototype. For example, a DVB-SI Electronic Program Guide or home
automation functionalities are not used.
The SmartHome Navigator is activated on the TV, which is the main device
in this scenario. The navigator is operated by a pointing device or cursor
keys. The navigator application data may stored residently on the clients
device or can be downloaded. In this scenario the WWW access will be used
to learn about the current TV program. The menu item "TV Program" is selected.
The SmartHome Navigator Home Page
The selection activates an embedded WWW browser with a pre-configured URL.
The access to the WWW browser connects the HomeNet via ISDN to an Internet
provider, and the selected WWW site is displayed in the browser. The WWW
site delivers a HTML document with embedded code, which can be used to
control the tuner of the TV. This results in a direct switching from the
Navigator to TV watching.
The integrated SmartHome WWW browser
In this case however, the SmartHome Navigator will be used to access another
application which was transmitted to the client via DVB data-broadcast
in advance (e.g. over night), or on-demand from a DVB object caroussel.
Both methods are specified by DVB to transmit via Digital Video Broadcast
content and application data to the client via "push". This can be done
for free of following a prior subscription for specific content. The SmartHome
Navigator provides in this case two applications in the MHEG application
format. The MHEG format is a multimedia application format suitable for
Set Top Boxes and broadcast distribution.
Interactive Application selection
The activation of one of the applications ("Das Labor" - german for "The
Laboratory" - realised together with Ponton European Media Art Lab) moves
the SmartHome Navigator to the background and the MHEG application is visible.
The MHEG application consists of a number of pages describing a talkshow:
the guests, the topic and additional information. The MHEG application
controls the TV tumer and displays a small Picture-in-Picture style video
in the upper left corner. The video is delivered via digital video broadcast.
It is possible to select one out of three related broadcast channels of
the same talkshow, or to enlarge the video for "classical" TV full screen
mode.
Complementary Information for the Talkshow: Das Labor
It is now possible to join a preconfigured Internet chat channel and
to contribute via ISDN to the on-going discussion about the topic of the
talkshow. The Internet chat is therefore used to enable a active role of
the user in the scenario. Moreover, via an integrated ISDN-based video
phone it is possible to call the talkshow production site and to take visually
part in the talkshow. The images of the video phone can be feed to the
broadcast.
Conclusion
The scenario makes use of different technologies. Moreover, it enables
to combine the different technologies to offer new services. The capabilities
of the home network and the preferences of the user determines the functionality:
none of the technologies described above are essential for the scenario
(except for the TV part), even a subset of the scenario may build a
valuable application. The scenario can be scaled according to available
technology.
The role of the internet technology in the scenario is two-fold: On
the one hand the WWW provides additional information about the broadcast
TV streams, including TV tuner control via browser-extensions, on the other
hand the Internet Chat services enable to take part in the ongoing broadcast
service. DVB databroadcast is used to compliment the capabilites of online
network media to address specific user groups.
The approach described above does not primarily target the introduction
of new technology. Instead, existing features of the WWW technology and
other communcation are combined. The combination requires on the one hand
well prepared content provision and on the other hand an integrated multiformat
receiver and decoder. The approach takes advantage of the capabilities
of DVB for video and content transmission and of the on-line capabilities
of Internet technology.
References
This section covers links to partners who have contributed to the scenario
and to sites with more information about a specific technology.