UNIFIED ARCHITECTURE FOR TELE
Contents
1. Time Interval 10 min z Reserved Time Intervals 30 min Booking uh Delete Reservation Back to Instruments Back to ExperimentOnline Back to ExperimentOffline Fig 2 1 Scheduler 3 3 Appendix Models of UTEA 3 1 Function Related Model according to Rumbaugh 1 User Client f 1 TAN NON N VN i Audio Transmitter M Audio data AudioCard MRawdata Microphone oN UserProfiie Data 2 N N Audio stream UDP IP go a Video Capture ExperimentiGroupProtilo NN Vie stream Video Transmitter j Video data gt Card Raw data Video Camera update ra UDP IP A Status parameter Output parameter TCP IP s EN Input parameter Raw data ES EL Y y i CNN i Access Control Eaparimont Instrument cess Control lnisrace Hn TCP IP Input parameter E E _Userdata input parameter Output parameter Experiment Groupdata Input parameter SS Sa Time settings Connection settings Archive data Archive media TCP IP Database Data telegramms TCP IP gt HTTP Server a im CaGlSripts los HTTP x i in Status OK CN b I UName Password TCP IP s HTML Documents Fig 3 1 Functional Model of UTEA 32. ExperimentOnline is chosen if the user wants to have streaming media besides the device control Therefore an Audio VideoReceiver 8 and a Control Applet for the experiment are downloaded Now the user has the possibility to watch a regular experiment of others or to initiate an experiment for his own with corresponding access rights The appropriate experiment parameters are entered in the Control Applet and the file names for saving in output parameters for the later analysis are specified here The parameters can only be sent if the status is active experiment time has started After sending the suitable experiment parameters from the Control Applet the Access control Fig 3 2 Simplified Object Model checks the input parameters on their legitimacy ParameterRange in order to prevent a damage of the machine Subsequently the parameters are sent simultaneously both to the data base for later analysis and to the Experiment Interface After the experiment has started current output parameters in the Controller are shown and the corresponding experiment parameters are saved in a file specified by the user ExperimentOffline is selected if the user does not want to have any streaming media Only a Control Applet corresponding to the instrument is downloaded which accepts input data and stores it in the data base From there in a free time slot the parameters are selected again and sent to the Experiment Interface All in output parameters are also
3. 3 2 E Dependent on Experiment BH Independent on Experiment Simplified Object Model according to Rumbaugh 1 ome na has a S ExperimentOnline a Audio Vi Recei p hasa Instrumentshas a Main udio Video Receiver pans A has a JN ExperimentOffline has a has a receive Settings send receive has a lt gt GroupProfile has a g has a ete Registration OnlineControl OfflineControl senareceive has has a UserProfile receive Scheduler has send receive receive send receive end receive Send feceive send receive Analyser ta send receive onu receive receive send has a send receive receive send receive send ml sendireceivel HTTP Server raseivelsend GraphicAnalyse send i has a Video Transmiter Access Control send receive has a s nd receive send has a LP m MediaPlayer i send send receive yr receive send i send receive Audio Transmitter HTTP Documents send ra send receive hasa send send receive ll ar Video Capture receive iv n a receive send Audio Card Experiment Interface receive receive send receive sendireceive receive send spnd send receive send ndsend send receive send
4. streaming media After that the client derives the best audio and video format and informs the server about it Furthermore audio video can optionally be turned on off b Scheduler Only one person at the same time has active access to the respective experiment however other persons have the possibility to watch the experiment passively There are two possibilities to book an experiment Reservation in a definite time interval Fig 2 1 above In the graphical user interface a timetable is offered to the user showing which times are booked by an experiment Here a green joist means the Own User Time and a red joist Booked by other Users At first the user has the possibility to select a particular week and a particular day In the second step he chooses the experiment time e g 12 00 18 00 subsequently the experiment duration of 6 hours is reported to him After being sent to the data base the selected times are represented graphically in the Scheduler the Timetable Beyond this the booked time can be cancelled by selection of the interval and activating of the button Delete Reservation The system also guarantees that an instrument always is reset into its starting point before a new test starts Therefore the user reservation always represents the actual 4 c beginning and end of an experiment If the user has booked until 18 00 and it takes two minutes to reset the machine then parameter can be sent to the machine un
5. Camera Micropho receive send receive send p Device ur receive receive send Fig 3 2 Simplified Object Model of UTEA 3 3 3 Entity Relationship Model according to Chen 2 4 fe Ty yf N FK NS fn ON A ON ut ES Pa TN a ON P x di TAE fe TN PE EN ES F AN y NC Firstname Lastname f UName Password Stret Zip Cade y Location Country Jl mme eval Pos nm m een f i k sas pare Vu LS ON eke RT a eae Fo E S py lt Y Y did Grop UserProfile f E Rights JUNI Sb N Tl i UD GroupProfle 7 Ne VN UD Pd IS A gt Se a PES po a ISA s p Settings n 4 EE EN CN P NE Sees SS seeds gt c pet et rdi z di fe N has access Analyser Audio us X es m n om Jl am N Videorama ON Password pz i d X f P AucioForma ks Wey J E du uM i UID N M E N id PA UName N d ans gt m fo 2 N f Mou A NE a 1 eso ji OunerPat b Seed cesa LA a b ZTN Administrator ria Data base 3 A V n p 1 Ed A es Data 1 ExplD X lt books gt SS xd Mu A M N ee E See sae M ae a N See gt d Y y D Tien Mee E S ExpTypID BenpD d Seo Se NS a an bd N UD fon e rstName y JC Sca ph SE z V J ExpTyp MN E
6. saved for the analysis in a user defined file d Analyser g In output data can be loaded in an analysis tool with graphical interpretation in an extra window Moreover archive multi media files corresponding to the experiment can also be chosen The analyser offers the user the possibility to interpret input output data of the chosen experiment corresponding to the user s access rights Not only the user but also the members of his accompanying group if they have got reading rights from the group leader may have access to the archive data This should promote group learning Data In Output data are listed in an Excel table which can be downloaded in order to analyse it offline Back to the Main Menu Here the user navigates back to the main menu again to take up corresponding services 2 2 Example of a GUI Fig 2 1 shows an example of a GUI the scheduler in UTEA It illustrates both the reservation of a definite Time Interval and the reservation of an indefinite Time Interval Scheduler 04 06 2001 10 06 2001 Ica x Scheduler Select Week Help Reservation of a definite Time Interval Instrument Robot Experiment Time 12 00 Availlable Time 6 Hours Time Critical Nein 18 00 Booking C Mo Tu Delete Reservation C We Back to Instruments C Th Back to ExperimentOnline C Sa Back to ExperimentOffline C Su Reservation of a undefinite Time Interval Queue
7. uses UTEA for the first time must set up his user profile This ensures that the user must identify himself explicitly by a chosen Username and Password Due to the fact that the operation of UTEA is combined with costs a billing system is required In order to authenticate a user a digital signature has to be used You can get it in a national administration centre for digital signature by sending personal authentication data like first name last name address passport identity card number driver s license number If your personal data has been checked successfully you will obtain your private digital signature With that you can pay on the internet After sending a registration form for the UTEA to the user which contains the user profile it has to be confirmed with the private digital signature On the server side a decoder checks the digital signature and if the authentication holds the user can operate with UTEA The amount of the charges depends on the type of instrument the duration of reservation and the type of reservation reservation in a definite time interval reservation in a queue Change User If a user wants to change his profile for any reason then a registration in the data base is required After activation of the button Change User his user profile appears in a window of its own and he only needs to modify the fields New Instrument GroupProfile To be able to carry out definite experiments the user must set up a New I
8. NE DRE oon me Ps m Access a N m ai N Em po Ter has B See d N f e p n Me m cil ExTyplD m lt has access Scheduler PN M ome J Beiter la sue duds E ee EN X ES P JE AccID 9 io d E E sie Lo session UD N general N KC N P IN a Descripton NN a p uc SEX N A uw l Critical y N EM NT y F a r4 x N Me P Descripton Reservation Queuing JC ys J cc free Lo S AS eee x Range Se ye 1 E A resa ESN p i AS Ne edu OS ER e Ru QE de freeWeek Ji freeDay Timestot m f i a v E ExpBegin ExpEnd Timeout Day Week resTimeslot NC N J j Er E See Ne Uses 2f SNP SE M dh Sf Fig 3 3 Entity Relationship Model of UTEA 3 References 1 J Rumbaugh Objektorientiertes Modellieren und Entwerfen Hanser M nchen 1993 2 G Vossen Datenmodelle Datenbanksprachen und Datenbank Management Systeme Addison Wesley Bonn second edition 1994 3 H Pommer Software Design f r Tele Experimenting Diploma University of Salzburg 2001 4 P Chen A preliminary framework for entity relationship models North Holland Amsterdam 1983 5 A Tanenbaum Computernetzwerke Prentice Hall M nchen 1997 6 C R hrig A Jochheim Remote Control of Laboratory Experiments Proc of the 19 ICDE World Conference on Open Learning and Distance Education Vienna June 1999 7 Project Page Re
9. UNIFIED ARCHITECTURE FOR TELE EXPERIMENTING Hermann POMMER Armin VEICHTLBAUER University of Salzburg University of Salzburg Institute for Computer Science Institute for Computer Science Software Quality Lab Software Quality Lab hotspot utanet at aveichtl cosy sbg ac at Eberhard MULLER University of Salzburg Institute for Computer Science Software Quality Lab emueller newmedia at Keywords Unified Tele Experimenting Architecture UTEA Application Programming Interface API Graphical User Interface GUI Object Model Functional Model Entity Relationship Model ER Model Abstract The paper provides a proposal for the design of UTEA It basically consists of simple client server architecture with device drivers on the server side and a GUI on the client side as a front end Streaming media is used to supervise the execution of the experiments The UTEA is visualised with according graphics and the process structure gives a short overview of how to work with the system The chapter general description and functionality of UTEA provides the user manual in which also the GUI with the Scheduler is illustrated The final part of the paper contains several models which are useful to describe the Tele Experimenting system The simplified object model demonstrates the structure of UTEA the function related model shows transformations of data and its interdependence and the entity relationship model illustrates a conceptional datab
10. ale Systeme im virtuellen Labor http rsvl fernuni hagen de 8 Sun Microsystems Java Media Framework http java sun com products java media jmf 2 1 1 index html April 2001 9 H Schulzrinne S Casner R Frederick and V Jacobson RFC 1889 RTP A Transport Protocol for Real Time Applications http www normos org rfc rfc1889 txt January 1996 10 H Schulzrinne RFC 1890 RTP Profile for Audio and Video Conferences with Minimal Control http www normos org rfc rfc1890 txt January 1996
11. ase design In conclusion UTEA is usable for every experimental environment due to the design of generic components allowing easy adaptation for special purpose Additionally a new User and Instrument Administration has been developed supporting group management and giving special access rights In order to give our Tele Experimenting system full functionality a scheduling system reservation in a definite timeslot reservation in a queue and a billing system have been worked out 1 User interfaces of UTEA 1 1 Client Server Architecture Fig 1 1 shows the Client Server Architecture of UTEA It illustrates general objects Dependent on Experiment Independent on Experiment and their correlation Dependent on Experiment EE Independent on Experiment Server on Control Room Internet Interface Client Server Filetransfer via TCP IP Mediatransfer via UDP IP further Operating Systems Fig 1 1 Client Server Architecture of UTEA 3 1 2 Application Programming Interface API The UTEA has two API s Fig 1 2 Device API User API The Client GUI is a Webbrowser with HTML Documents and Java Applets therefore the UTEA can be executed on every operating system The user can select different functions and set the corresponding parameters All data are transferred via TCP IP 5 streaming media 8 via UDP IP 5 On the server side the Experiment Control uses multimedia settings to create an Audio Video Stream 9 10 and T
12. be multi media capable for audio visual streaming media 7 In user specified files media data audio and video and parameter data experiment dependent can be stored and later interpreted with analyse tools 6 This is realised by a data base to which also other colleagues or group members shall have worldwide access with corresponding authorities reading writing In a second construction phase asynchronous like eMail FAQ Board and synchronous communication modules like Live Chat Whiteboard Videoconferencing tools shall be integrated to allow teamwork with other colleagues or to obtain help from teachers 2 1 Functionality of UTEA Via internet HTML Documents are transferred by using Hypertext Transfer Protocol HTTP A Webbrowser offers the user interface After loading the main page from the server a general description about UTEA and its instruments is displayed At the bottom of the main page the service buttons Registration Disconnect New User Change User New Instrument GroupProfile Change Instrument GroupProfile Selection of Instrument s and Close UTEA are offered The services associated to the buttons are following 1 Registration A user must register at the system with Username and Password If this is successfully carried out then the status is Connected otherwise the status is not Connected 2 Disconnect At any time the user has the possibility to disconnect from UTEA again 3 New User A user who
13. f UTEA which makes it possible to control remote laboratory instruments via the internet A data base serves for the initialisation and provides specific information 6 like user profile type specific instrument parameters experiment dependent in output parameters reservation information specific system settings The experiment can be operated both Online 7 supervised controlled by audio and video feedback on the screen and also Offline In both cases there are different reservation possibilities The following table shows the correlation between a Type of Experiment and Scheduling Table 2 1 Correlation between Type of Experiment and Scheduling Type of Experiment Online Offline Scheduling Reservation in a Fixed predefined times Fixed predefined times definite time interval Reservation in a Predefined time interval without Predefined time interval without queue definite times definite times Begin of the experiment is selected Begin of the experiment is selected with the first fit method with the first fit method The experiment beginning is signalised via SMS eMail etc In order to finance the project a charging system is introduced Reservation in a definite time interval will be combined with higher costs for the user than reservation in a queue The experiment can be prepared executed and evaluated in offline mode by means of a local PC and operating system with a Webbrowser In online mode the computer also must
14. ime Instrument Settings control the experiment Experiment Control Device Audio Begin d Output Video End arameter or Media User Group Administ of Multimedia Scheduler Instrument Analyser Data Administ Instruments Settings Settings Administ Server Registration Internet Filetransfer via TCP IP Mediatransfer via UDP IP i Interface Client Server Client PC Client PC Client PC User API f f f Client GUI Client GUI Client GUI Fig 1 2 API of UTEA 3 1 3 Process Structure Fig 1 3 shows the Process Structure in order to operate with UTEA The ordinal numbers demonstrate the typical usage of UTEA 5a Send controlled parameter to instrument and save it in the data base 5b Receive topic parameter and save it in the data base Instrument Server Interface Client Server 2 Status Connected not Connected 1 Login Username Passwort or set up UserProfile 4 Confirm access rights via eMail 3 Select instrument and define group 6 Receive aaitent tput parametet 5 Book time for instrument and set 3 i 7 Load analysis tool or data sheet input parameter for experiment Client PC Webbrowser and GUI Fig 1 3 Process structure of UTEA 3 2 General Description of UTEA This chapter provides a general description of the system architecture o
15. nstrument GroupProfile At this point the user has to decide himself whether he is a group leader default or only a member of a defined group for a definite instrument If the group leader wants to supervise several persons he can assign a unique group name which has to be used by the group members If a user is a group leader then he also has reading access rights on his members and therefore he can analyse their results Beyond this there is the possibility that the group leader also assigns read authorities which permit the single members to examine her results mutually Change Instrument GroupProfile If a user wants to change Instrument GroupProfile then first a registration in the data base is required After activation of the button Change Instrument GroupProfile the fields of the profile can be modified in an extra window Close REX UTEA is ended and the Browser Window is closed Selection of Instrument s If the user of the system has definite access rights to execute experiments then he can select an instrument from the drop down menu in which a description of the chosen instrument and its functionality are offered simultaneously At the bottom of this side the buttons Settings Scheduler Experiment Online Experiment Offline Analyser Data Back to the Main are offered The services associated to the buttons are the following a Settings With the help of Settings the user can select his best connection to the WWW regarding to
16. til 17 58 The remaining two minutes are reserved as time buffer which is different for every instrument in order to reset into its original position An instrument at which the experiment end isn t foreseeable represents an exception This is signalled to the user as time critical device by the database If an experiment at such an instrument lasts longer than the reservation time is foreseen then the following reserved experiments are cancelled in order to avoid an appointment collision In this case high safety is more important than guaranteed execution Reservation in an queue Fig 2 1 below Such reservations can only be performed with not time critical instruments A predefined time interval e g 10 min 30 min 1 h can be selected and sent to the data base by pressing the button Booking After that the reserved interval s is are shown in the scheduler in the listbox and they can be cancelled by pressing Cancel while they are selected The experiments in the queue are executed in free timeslots according to the first fit principle To make such experiments online executable the beginning time s must be signalled to the user via eMail or SMS The fees in a definite timeslot must be more expensive then in an indefinite queue because in the latter free time slots in the scheduler are filled up For this reason a better system performance can be reached through intelligent scheduling ExperimentOnline and ExperimentOffline
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