1 Introduction
The operation of information industry mainly
depends on the three supported networks which are
telecommunication network, the Cable TV network and
Internet. As far as China is concerned, in fact, it has
two networks which are telecommunication network and
the Cable TV network. At present, the
telecommunications networks and the Cable TV network
are basically independent of each other. We can't
communicate between the two operations systems. But the
United States and Britain in the 1990s allowed
telecommunications operators and cable TV operators to
enter the market of each other. And then they can
communicate between the two operations systems. In
China, the communication between the two operations
systems is one of the most important solutions in the
convergence of three networks. The digital television
multimedia message service system we researched can
achieve the convergence of the three networks in the
application layer.
At present, the main factors restricting the
development of Digital Television are lacking of funds
and there are not the authorized user, and are lacking
of content. The system this paper designed can achieve
interoperability between Cable TV network, the Internet
and telecommunications networks. The abundant contents
on the Internet and telecommunications networks will be
presented on the Television through this system.
According to statistics, there are currently
approximately 20,000 SPs (Service Provider). They
provide a lot of contents for value added services.
Similarly, with the adoption of this system, these
Service Providers can access to the Cable TV networks
and provide abundant contents to the Digital Television
users. Thereby, it promotes the development of the
Digital Television.
Through the Digital Television Multimedia
Message Service System, the user can receive the
multimedia message which sends from Internet and mobile
phone. If there is a return channel, subscribers can
also send message to Internet, mobile phone and
television station. So this will greatly enhance the
level of domestic information. And it contributes to
achieve convergence of three networks in the
application layer.
2 TVMMS Reference Architecture (Note 1)
2.1 TVMMS in MMSE
Figure 1 shows a unified Multimedia Message
Service Environment (MMSE, Multimedia Messaging
Service Environment). It includes Digital Television
Multimedia Message Service TVMMS system; the mobile
communications networks MMS system, the Public
Switched Telephone Network (PSTN), Internet and other
MMS systems. The MMSE provides all the necessary
service elements, e.g. delivery, storage and
notification functionality. These service elements may
be located on one MMS system or be distributed across
several different MMS systems. This MMSE makes these
Multimedia Message systems which distributed across
several different networks interoperability.
2.2 TVMMS Reference Architecture
Figure 2 shows the TVMMS system architecture.
The function entity/module which is composed of the
TVMMS system and the interface between them are listed
below.
2.3 TVMMS Function Entity and
Interfaces
UA (User Agent): User Agent is the application
layer's software which located on the STB. It provides
the function of supporting for the TVMMS service. The
user can receive, watch, write and send Digital
Television Multimedia Message through the user agent.
The TVMMS User Agent shall provide the following
application layer functionalities. (
Note 2)
-
The recipient of the message from TVMMS Relay/Server,
including multimedia message and notification
message;
-
Presentation of the multimedia message to the user;
-
Multimedia Message composition;
-
Submission of the multimedia message to the TVMMS
Relay/Server;
-
Decryption and encryption of a MM;
-
Storing of the message into STB;
-
Management of the message store in STB.
TVMMS Relay/Server: The MMS
Relay/Server is responsible for storage and
notification, reports, and general handling of
messages. The TVMMS Relay/Server is in the core
position in the whole TVMMS system. The TVMMS
Relay/Server element can be integrated together, also
can be separated into two elements. They can
communicate through MM2 interface. The TVMMS
Relay/Server shall provide the following
functionalities:
-
Receiving, sending and forwarding the multimedia
message;
-
Conversion of the message format between the TVMMS
Relay/Server and the External Server (e.g. Email
Server) or between TVMMS Relay/Server and the other
systems;
-
Multimedia Message notification to the TVMMS User
Agent;
-
Routing forward Multimedia Message to the different
TVMMS Relay/Servers;
-
Generating and routing forward the read-reply
reports;
-
Analyzing addresses of messages, and routing forward
the message according to the addresses information;
-
Temporary storage of the TVMMS messages;
-
Ensuring that messages are not lost until
successfully delivered to another MMSE element.
-
Supporting for DRM(Digital Right Management);
-
Generating charging data records (CDR);
-
Filtering the message according to the user
information;
-
Checking the estate of the STB; e.g. opening the STB
and closing the STB. Supporting TVMMS message or not.
If there are returned channel.
External Server: External
Server, for example Email Server etc, can implement
"television mail" function. We can send normal email
to the specified television. External Server didn't
belong to the functional modules which TVMMS need to
have.
Management and Control: The
Equipment of management and control is responsible for
the management and control function of TVMMS System,
such as system parameter configuration, addressing,
routing, charging parameters, the control of user
jurisdiction and the operation and maintenance of the
TVMMS System.
Billing System: The billing
system shall bill the users and VASP according to the
CDR that the TVMMS Relay/Server generates.
Electronic Program Guide(EPG):
EPG is an on-screen guide to scheduled broadcast
television or radio programs, allowing a viewer to
navigate, select, and discover content by time, title,
channel, genre, etc.
TVMMS Message
Storage Center: TVMMS is a storing
and forwarding system. Upon the TVMMS Relay/Server has
received the message, it caches the message and checks
the address information. If the recipient User Agent
located on its range, the TVMMS Relay/Server will send
this message to the TVMMS message storage center. Then
the TVMMS message storage center returned a URI of
this message to the TVMMS Relay/Server. The TVMMS
Relay/Server notified recipient User Agent there are
new messages arrived (this notification include how to
fetch the information of this TVMMS message).The TVMMS
message storage center deleted this information (or
deleted after a certain period of time), if the users
receive this message successfully. If the users didn't
download this message during a period of time, the
TVMMS storage center also deleted the message. If the
recipient User Agent didn't locate on its range, it
needs forward the message to the recipient User Agent
which located on the TVMMS Relay/Server according to
the routing information. After received the correct
response information, the TVMMS Relay/Server will
delete the massage.
TVMMS user databases: The
TVMMS user database shall provide:
-
Management of the TVMMS user subscription
information;
-
Management of the user access control information;
-
Set of rules how to handle incoming messages and
their delivery;
TVMMS VASP: The TVMMS Value
Added Services Provider shall provide value added
services to the TVMMS users, such as music, TV cards
etc. The TVMMS VASP connected with the TVMMS
Relay/Server through the MM9 interface.
The interfaces in the TVMMS reference architecture
are:
MM1: the reference point between the TVMMS User Agent
and the TVMMS Relay/Server;
MM2: the reference point between TVMMS Relay and TVMMS
Server. In specific implementation, Relay can be
integrated with Server into a same physical device;
MM3: reference point between TVMMS Relay/Server and
External Servers;
MM4: reference point between TVMMS Relay/Server and
management control Server;
MM5: reference point between TVMMS Relay/Server and a
billing system;
MM6: reference point between TVMMS Relay/Server and
message store center;
MM7: reference point between TVMMS Relay/Server and
user databases;
MM8: reference point between TVMMS Relay/Server and
another TVMMS Relay/Server;
MM9: the reference point between TVMMS Relay/Server
and VASP (Value Added Services Provider).
MM10: reference point between TVMMS Relay/Server and
?Electronic Program Guide(EPG);
3 Conclusion
The development of digital television and
alteration of the transmission network is the
important revolution of the Radio and Television
system. It will change the people's live style in a
way. The commercial success of digital television
multimedia message service system discussed in this
paper will greatly enhance the information level of
the family and societies, reach the service
application of digital television. And it is conducive
to the development of digital TV terminals as a family
information center. In China, the Cable TV network,
Internet and telephone network are independent each
other. It contributes to achieve convergence of three
networks in the application of services.
4 References
3GPP TS 23.140v6.11.1: Technical Specification
Group Core Network and Terminals, Multimedia Messaging
Service, www.3gpp.org.
3GPP TS 22.140v6.7.0: Technical Specification Group
Services and System Aspects, Multimedia Messaging
Service, www.3gpp.org
ISO/IEC JTC 1/SC 29 11172-3 Coding of Moving pictures
and Associated Audio for Digital Storage Media at up
to about 1.5 Mbit/s. 1993
ISO/IEC 14496-1 Coding of audio-visual objects-Part1:
Systems
ISO/IEC 14496-1 Coding of audio-visual objects-Part4:
Conformance Testing
ETS300429:Digital broadcasting Systems for television,
Sound and data services; Framing structure, Channel
Coding and modulation for Cable system(DVB-C spec)；
ARCIDIACONO, A.: 'Multimedia services and data
broadcasting via satellite', ibid., pp. 33-37
DRURY, G. M.: 'DVB channel coding standards for
broadcasting compressed video services',
Electvon. &
Commun. Eng.J., February 1997,9,
(I), pp.11-20
WAP-205-MMSArchOverview-20010425-a,
http://www.wapforum.org
|
