AGENT BASED INTERACTIVE TELEVISION SERVICE FOR AN
EXPERIMENTAL MULTIMEDIA SYSTEM
Markosz Maliosz
1, Károly Farkas
1, István Cselényi
21
High Speed Networks Laboratory, Dept. of Telecom. and Telematics, TU Budapest
Stoczek u. 2., H-1111 Budapest, Hungary,
Phone: +36 1 4633110, E-mail: [email protected]
2
Broadband Team, Dept. of Network Research, Telia Research AB
Vitsandsgatan 9, S-123 86 Farsta, Sweden,
Phone: +46 8 7138173, E-mail: [email protected]
Abstract
The EMMA/SIGNE [1] experimental system is designed for supporting any kind of telecommunication services. The implementation of the first prototype service, called Teleconference [2], was finished in 1997. However, the general validity of the EMMA/SIGNE concept has to be checked for several multimedia services. Therefore new teleservices have to be built up which have both unique parts and common components in each supported service. The system should be validated for the service specific and the general parts separately. This paper introduces a new teleservice called Interactive Television and summarizes the service specific and general system components to be taken into consideration during the adaptation of the system.
Key words: Multimedia, Telecommunication Service, Interactive Television
1. Introduction
In spite of the current video and/or audio streaming systems, [3,4,5] we use a general service platform, which has advantages compared to dedicated systems. With our abstract level resource management we can handle every kind of applications with their requirements. Moreover, the current systems do not care much about the network management. They concentrate on to take the most of the available network resources. These systems assume adaptive applications using scaleable coding and transmitting mechanisms [6,7,8,9]. In our system, the user applications are built up from reusable building blocks controlled by the system, assuring re-negotiation with the application.
The goals of implementing this experimental system are: create an universal system for arbitrary multimedia service and demonstrate its flexibility. The Interactive Television service
is introduced in the followings as an example to prove this. Since the first EMMA teleservice is a persto-person, on-line distributed multimedia application, Radio and TV (i.e., machine-to-person, on-line, broadcast), Juke Box, Movie on Demand, Multimedia Library (i.e., machine-to-person, off-line) and wrapped IP applications were selected as future services.
The main structural parts of the EMMA/SIGNE experimental system and their relationship are shown in Figure 1. The components are playing an important role in the service management and are introduced in the followings.
There are three main entities in the experimental system: · Network Operator
· Service Provider · End User
Session Set-Up
Naive users can join to the system by surfing with their WWW Browser onto the homepage provided by SIGNE. After registration and selection of the service (and eventually the service provider), they can order a new session or modify the ongoing session by a Java-based Service Control interface. They can give their quality requirements in user-friendly terms (like high, medium or low resolution; big, medium or small picture size; etc.), which will be mapped to specific resource parameters by the system. SIGNE Core collects the quality requirements of each party, allocates the network resources through the Network Control unit according to the commonly accepted quality level. After that it starts the session by sending a confirmed state message to the terminals’ Network Access Program (NAP) which uses the Application Launcher Daemon (AppLD) to start the Application Building Blocks (ABB) (e.g. audio, video) [2].
SIGNE EMMA Terminal WWW Browser WWW server Network CTRL Video Text Audio Network Access Program Local View of Service Instance Application CTRL Consumer Service CTRL Native ATM API Application Launcher Daemon Data Bases EMMA Terminal WWW Browser Video Text Audio Application CTRL Service CTRL Program Provider Native ATM API Application Launcher Daemon Network Access Program Local View of Service Instance SIGNE Core Service Instance ATM ATM IP IP
Figure 1. The Interactive TV Based on the EMMA/SIGNE Experimental System
The EMMA Terminal
EMMA is realized on a general-purpose workstation. The main structural parts of the terminal are:
· Network Access Program for service consumer and provider in order to make the easy use of the User Applications possible.
· User Applications (UA) containing the Application Building Blocks that provide the multimedia services to the users. The ABBs can access the ATM network through the specially developed EMMA component: the Native ATM Programming Interface.
The term ABB must be explained: the idea is to make a program which can be recycled for all the multimedia applications which use the same representation media (for example a video conference service and a video on demand service can use the same video-ABB). Since there are two main parts that have to communicate, we also need a possible high-level protocol between NAP and the UAs.
2. The Interactive Television Service
Basic Idea
Interactive TV is one of the services that are based on EMMA system. The basic idea of the application is to give television service to several clients just like any other TV-s we know today, however not only the usual television services like moving-pictures, teletext channels but also the possibility of interactions when watching the program [10]. So the user will be able to play interactive TV-games, forward his opinion or talk to the moderator. This is possible because of the system's duplex "interactive channels". The greatest benefit of this system: it provides enhanced functions, on-line
information, statistics that cannot be found in current television systems. Further advantages are: high quality – the program is transmitted on the network in digital format with the required bandwidth (thanks to the ATM), so there is no quality loss like noise over the open air broadcast; coping with the distance – the network can reach even certain points, to where normal radio waves cannot get. The user-friendliness is provided by easy-to-understand metaphors on a JAVA-based Graphical User Interface, which helps the naive user to use all the benefits of this multimedia service.
Features
With the Program Selection function the user can get information about every television station which is currently working, and also the actual program on each station, so he can choose easily the perfect station for himself. This function is similar to the TV Program Newspaper. With the help of Content Selection the user can choose the desired program with the support of the program-agent, so he has only to give the content of the program and the agent draws up a list with the suitable TV stations. Content Classification means that each television program is described by rates (violence, sex, slang, age limit) and can be forbidden at a certain level so parents can protect their children from any harmful programs. The service gives Instant Statistics too, so each station knows exactly how many users it has and this way it can optimize its program. The users can send their votes to make up a Hit List from the best music songs. They can also call up and talk to the presenter or the invited guests on-line. The user can use the data line also to ask questions. The presenter can address and interview the users from the whole world. In the Request Hours users can send their requests (e.g., favorite music songs…) to the TV Station.
TV
Agent
TV
Station
#1
TV
Station
#2
Watcher
Program Statistics Program Statistics TV C hann el (P ictur e, S ou nd , T ele text) M essag es, R eq ue sts Program Selection TV Cha nnel (Pic ture , Sou nd, T elet ext) Mes sage s, R eque sts Filter Filter TV Program Database Teletext Database TV ProgramDatabase DatabaseTeletext
Figure 2. The Structure of Interactive TV
Structural Overview
The picture (see Figure 2) shows the basic components of the service and the relations between them. The Agent node contains the information and statistic data about all TV Stations. If a new Station appears, then it must contact the Agent, send the actual program information (e.g., program titles, duration of programs, filter values, recommended age limit, etc.). These items are stored in the Agent’s databases. If the user would like to watch a program first of all the Watcher node has to contact the Agent. After contacting the user can select the desired TV Station and the Agent forwards this request toward the suitable Station. So these are the steps of the operation:
1. Visiting the Service Provider’s homepage 2. Registration
3. Selection of the Interactive TV service
Thenceforward the user can look at the offer and select the adequate station. After this point the Watcher node closes the connection with the Agent node and opens the connection with the Station node, which starts transmitting the program and the attached data (teletext, subtitling) towards the Watcher node. The submitted information pass through a filter to eschew undesirable programs.
MAGIC model [3]. TCSD is an object structure that contains the whole description of the service used.
The Interactive TV service has 3 Party types: TV Agent, Watcher and TV Station. These parties can communicate with each other over USMs (User Service Modul) (e.g., the Agent and the Watcher can communicate over the USM TV Control, the Watcher and the Station can communicate over USM TV Channel and USM Interactive, etc.). USM is the basic building block of a service. It provides a grouping function, combining one or more information types (e.g., audio, video) used in a service into a single group. An USM consists of ASMs (Abstract Service Module) which represent basic information types that may be used in a multimedia service (e.g., audio and video information types). ASM essentially encapsulates the attributes of the application layer of the service. (E.g., in this service the USM Interactive is built up by Voice and Vote ASMs, etc.) An ASM consists of SMs/ACEs (Service Module/Access Connection Element). SM represents the protocols used to implement a basic information type of a multimedia service. SM is unidirectional which means that one Service Module can only send or receive data. ACE defines the characteristics of the bearer connection. (E.g., the ASM Voice has two SM/ACE because it is bi-directional.) PE/PAE (Party Edge/Party ASM Edge) is used to define the relationship between the objects.
metaphors of the user into service control primitives (e.g., Add/Drop element) which are understandable by NAP. There are three Service Controls for all the three Parties (Watcher, Station, Agent). Only a new Service Control module has to be developed to provide a new multimedia application based on a certain telecommunication service
User Applications
The Interactive TV service uses nine kinds of ABBs for presenting video, audio and any other information to the user. The audio-ABB and video-ABB are reused from the first multimedia service of the EMMA/SIGNE system (teleconference service). The new ABBs are: subtitle, teletext, voice, vote, selection, program, statistic. These ABBs are the service specific ABBs for the interaction and enhanced features of the service and they have to be developed.
4. Conclusion
The EMMA/SIGNE experimental system has many benefits from the service management’s point of view. In spite of the dynamic routing paradigm, where unlimited network resources are assumed and the quality demands supposed to be fulfilled
in a dynamic and flexible manner, our system utilizes the central view of the service for full control of network and terminal resources. The main advantages of this system that the basic components can be reused and only the service specific components (Service Control, special ABBs) have to be developed for a new multimedia application; it provides a JAVA written platform independent user interface that can be accessed with a WWW browser.
Only a flexible experimental system can cope with the diversity of multimedia services. If the EMMA/SIGNE system is able to manage such a complex service like the Interactive Television then we can say without hesitation that this system can be adopted easily to new telecommunication services so it fulfills this requirement.
Acknowledgement
The reported research activities are made in the joint research program between the CARAT Laboratory of Telia Research in Sweden and the High Speed Networks Laboratory of the Department of Telecommunication and Telematics, Technical University of Budapest in Hungary. We would like to thank our colleagues in Sweden and in Hungary for the help during the design and implementation of this system.
Party TV Agent PE TV Cont. USM Inter-active USM TV Chan. USM TV Cont. PAE
Prg. PAEStat. PAESel. VoiceASM ASM
Vote ASMVideo ASMAudio ASMS.title ASMT.Txt ASMPrg. ASMSel. ASMStat.
SM SM SM SM SM SM
ACE ACE ACE ACE ACE ACE
Party
Watcher PartyTV Station
PE Inter-active PE TV Chan. PE TV Cont. PE Inter-active PE TV Chan. PE TV Cont. PAE Voice PAE Vote PAE Video PAE Audio PAE S.title PAE T.Txt PAE Sel. PAE Voice PAE Vote PAE Video PAE Audio PAE S.title PAE T.Txt PAE Prg. PAE Stat. SM SM SM SM SM SM SM SM SM SM SM SM SM SM SM SM SM
ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE ACE
References
[1] I. Cselényi, I. Szabó, P. Haraszti, N. Björkman, C. Gisgård, A Versatile Multimedia Platform, IASTED Int' Conf. on Applied Informatics, Innsbruck, Austria, February 17-20, 1997
[2] I. Cselényi, I. Szabó, G. Záruba, EMMA Teleconference Version 1.0, High Speed Networks Laboratory, Formal Meeting, Budapest, December 1996
[3] N. Björkman, I. Cselényi, A. Latour-Henner, G. Záruba, The EMMA Multimedia Conference Service, First International Conference on Information, Communications & Signal Processing, Singapore, September 1997
[4] Richard V. Ducey, Multimedia Broadcasting and the Internet, http://www.iif.hu/inet_96/b3/b3_2.htm [5] Ilija Lazarov, Kari Salkunen, Interactive
Television - ITV - Scenario, http://www.cet.hut.fi/Texts/Itv.html
[6] N. Davies, S. Pink, G.S. Blair, Services to Support Distributed Applications in a Mobile Network, in Proc. of 1st Int. Workshop on Services in Distributed and Networked Environments, Prague, Czech Republic, June 1994
[7] Y.I. Manolessos, M.E. Theologou, Dynamic application scaling as a means for QoS management, Computer Communications 20 (1997) pp. 393-405
[8] C. Diot, Adaptive Applications and QoS Guarantees, in Proc. of IEEE Multimedia Networking, Aizu Japan, September 1995
[9] M.I. Smirnov, Object-Oriented Framework for Scalable Multicast Call Modelling, 2nd International COST 237 Workshop, Copenhagen, Denmark, November 1995, pp. 19-39
[10] K. Farkas, M. Maliosz, Interactive Television Service based on ATM, Poster Presentation on the High Speed Networks Laboratory - Ericcson Traffic Lab. Formal Meeting '97, Budapest, Hungary, 1-2 Dec. 1997
