mobile tv testbed software

Use Case Analysis

Simple use cases for configuring the test bed.

Last modified: Cong Ly, 10/07/2008

User wants to add a new Video file to the repository

• Pre-condition: The video file does not belong to the current video repository
• On webpage, user clicks on the "Upload" tab.
• Select video to be uploaded from local computer.
• Select ESG file to be uploaded from local computer.
• Enter assigned PID - Provider ID for the video. Example: 0x777
• Enter assigned multicast IP for the video. Example: 224.0.1.2
• Enter video port. Example: 1209
• Enter an audio port. Example: 1210
• Click Upload
• Web browser can post video file and data to the test bed server.
• Web GUI create a new file folder for each uploaded video file and store the video there.
• Web GUI write the video file path to a config file, (Cong can decide how we implement this part)
• User waits for the browser to finish uploading. There will be a green status indicator showing the uploading.
• The system confirms the video file was uploaded.
• The system transfers the user to the "Video Files" tab
• The user can confirm the new uploaded video file is available in the repository.
• Post-condition: The video file is added to the video repository
• Note: this part is all handled by web GUI

User want to update DVB-H Network Parameters

• Pre-condition: DVB-H broadcast system stopped, since we got status function in webpage, this means DtPlay process must be in "stopped" status
• User clicks on "DVB-H Parameters" tab
• User sets the Carrier Frequency value, for example 538Mhz (possible values are integers between 470 and 750)
• Update dvbhparams.cfg with "Carrier_Frequency=538"
• Backend script will add "-mf 538" to DtPlay
• User sets the Convolutional Rate value, for example 1/2 (possible values are 1/2, 2/3, 3/4, 4/5, 5/6, 6/7 or 7/8)
• Update dvbhparams.cfg with "Convolutional_Rate=1/2"
• Backend script will add "-mc 1/2" to DtPlay
• User sets the Guadr interval value, for example 1/4 (possible values are 1/4, 1/8, 1/16 or 1/32)
• Update dvbhparams.cfg with "Gaurd_Interval=1/4"
• Backend script will add "-mG 1/4" to DtPlay
• User selects the bandwidth, for example 8 (possible values are 5 6 7 or 8)
• Update dvbhparams.cfg with "Bandwidth=8"
• Backend script will add "-mB 8" to DtPlay
• User selects the constellation, for example QPSK (possible values are QPSK QAM16 or QAM64)
• Update dvbhparams.cfg with "Constellation=QPSK"
• Backend script will add "-mC QPSK" to DtPlay
• User selects the transmission mode, for example 8k (possible values are 2k 4k or 8k)
• Update dvbhparams.cfg with "Transmission_Mode=8k"
• Backend script will add "-mT 8k" to DtPlay
• User clicks "Save"
• The system saves the changes to the dvbhparams.cfg configuration file.
• Backend script use the latest configuration from dvbhparams.cfg
• Post-condition: Dtplay parameters got updated.
• Note: Backend script name: updatedtplay.pl

 updatedtplay.pl API
 input: dvbhparams.cfg
 output: rundtplay.sh,  its content is the full command for DtPlay
 

User wants to update Timeslicing Parameters

• Pre-condition: DVB-H broadcast system stopped, since we got status function in webpage, this means timeslicer process must be in "stopped" status
• User clicks on "Time Slicing" tab
• User selects the MPE_FEC Frame value, for example 1024 (possible values are 256, 512, 768, or 1024)
• Update dvbhparams.cfg with "MPE_FEC_Frame=1024"
• Backend script will add "-n 1024" to timeslicer
• User selects the OFDM guard interval value, for example 8 (possible values are 4, 8, 16, or 32)
• Update dvbhparams.cfg with "OFDM_Guard_Interval=8"
• Backend script will add "-g 8" to timeslicer
• User selects the OFDM bandwidth, for example 8 (possible values are 5, 6, 7, or 8)
• Update dvbhparams.cfg with "OFDM_Bandwidth=8"
• Backend script will add "-b 8" to timeslicer
• User selects the Code Rate, for example 3 (possible values are 1, 2, 3, 5 or 7)
• Update dvbhparams.cfg with "Code_Rate=3"
• Backend script will add "-c 3" to timeslicer
• User selects the constellation, for example qpsk (possible values are qpsk, 16qam, or 64qam)
• Update dvbhparams.cfg with "Constellation=qpsk"
• Backend script will add "-o qpsk" to timeslicer
• User sets the Delta_t value, for example 350 (possible values are integers between 100 and 3000)
• Update dvbhparams.cfg with "DeltaT=350"
• Backend script will add "-d 350" to timeslicer
• User selects the algorithm used, for example P2OPT (this is a faked feature though, may remove later)
• Update dvbhparams.cfg with "Time_Slicing_Algorithm=P2OPT"
• Backend script will not do anything for now :-)
• User clicks "Save"
• The system saves the changes to the timeslicing.cfg configuration file.
• Backend script use the latest configuration from timeslicing.cfg
• Post-condition: timeslicer parameters got updated
• Note: Backend script name: updatetimeslicer.pl

 updatetimeslicer.pl API
 input: timeslicing.cfg 
 output: runtimeslicer.sh,  its content is the full command for timeslicer

User selects video to broadcast

• Pre-condition: DVB-H broadcast system stopped, since we got status function in webpage, this means vlc process must be in "stopped" status
• User clicks on the "Video Files" tab.
• The system lists all available video on the server.
• There are 5 tabs for each video file: File name, multicast IP, port used, PID assigned, and its corresponding ESG file name.
• Entries with existing check mark indicates it is currently in use.
• User selects video files that are not marked.
• User selects "Save" to submit the changes to the server.
• The system updates the videoslist.cfg file to reflect the changes.
• Backend script use the latest configuration from videoslist.cfg to update parameters for vlc and dataaggregator
• Post-condition: checkbox of the selected video is checked. vlc and dataaggregator got the correct parameters.
• Note: Backend script name: updatevlc.pl and updateproxy.pl

 updatevlc.pl API
 input: videoslist.cfg 
 output: runvlc.sh,  its content is the full command for vlc

 updateproxy.pl API
 input: videoslist.cfg 
 output: runproxy.sh,  its content is the full command for dataaggregator

User wants to update PSI/SI Configuration Parameters

• Pre-condition1: DVB-H broadcast system stopped, since we got status function in webpage, this means TS Null Shaper process must be in "stopped" status
• Pre-condition2: There exist selected video file in "Video Files" tab
• User clicks on "PSI/SI" tab
• Web GUI knows which video file are selected and grab the corresponding PID and multicast IP of that video file
• Web GUI saves the total number of video files, each video file name, their multicast IP and its PID to psisi.cfg.

 For example:
 video_num=2
 video1=abc.mp4
 pid1=0x777 
 video2=efg.mp4
 pid2=0x888
 video1_ip=224.0.0.1
 video2_ip=224.0.0.10

• User sets service_id value under PMT section, each video file selected needs to have its own service_id value and these values must be different (Web GUI may check the value to make sure they are different) and saves to psisi.cfg
• User sets PMT_id value under PMT section, each video file selected needs to have its own PMT_id value and these values must be different (Web GUI may check the value to make sure they are different) and saves to psisi.cfg

 For example:
 video1_service_id= 0x2B00
 video2_service_id= 0x2B01
 video1_pmt_id=0x31f
 video2_pmt_id=0x320

• User clicks "Save"
• The system saves the changes to the psisi.cfg configuration file.
• Backend script use the latest configuration from psisi.cfg to create PSI/SI python scripts (the sequence of the following matters)
• Backend script create new pmt.py files
• Backend script update pat.py
• Backend script update sdt.py
• Backend script update int.py
• Backend script update psimain.py
• Post-conditon: all the python scripts for PSI/SI table are ready.
• Note: backend script name: updatepsi.pl

 updatepsi.pl API
 input: psisi.cfg 
 output: A group of python scripts.

User wants to update ESG

• TBD
• this part may involve updating Flute FDT table based on ESG file size

User wants to start the DVB-H broadcast system based on current configuration

• Pre-condition: DVB-H broadcast system stopped
• User clicks on "Start DVB-H" button under DVB-H Parameters tab
• The webpage sends HTTP post message to http://cs-nsl-08.cs.surrey.sfu.ca:48000/ This http post message tells the back end script to start the whole system
• The back end script first do a system call to start vlc
• The back end script then do a system call to start flute (TBD, need to wait for flute part design)
• The back end script then do a system call to start dataaggregator
• The back end script then do a system call to start timeslicer
• The back end script then do a system call to start python scrips and TS Null Shaper.
• The back end script then do a system call to start DtPlay
• User open Nokia N96 cell phone, select mobile TV application and search for channel.
• Post-conditon: User can watch the video on their cell phone, all DVB-H broacast system components are up and running.
• Note: backend script name: /etc/init.d/nsl-dvbh start

User wants to stop the DVB-H broadcast system

• Pre-conditon: User can watch the video on their cell phone, DVB-H broadcast system is up and running.
• User clicks on "Stop DVB-H" button under DVB-H Parameters tab
• The webpage sends HTTP post message to http://cs-nsl-08.cs.surrey.sfu.ca:38000/ This http post message tells the back end script to terminate the main PSI/SI handler
• The backend script stops the TS NULL Shaper, vlc, timeslicer, dataaggregator, flute, DtPlay
• Post-condition: DVB-H broadcast system stopped
• Note: backend script name: /etc/init.d/nsl-dvbh stop

User wants to add a new video channel in the current playing DVB-H broadcast system

• Pre-conditon1: DVB-H broadcast system is up and running with some programs
• Pre-conditon2: There exist extra video file in video repository and its corresponding parameters have already been configured properly (see the above configuration user case for more detail)
• User clicks on "Add to DVB-H" button under DVB-H Parameters tab
• The webpage sends HTTP post message to http://cs-nsl-08.cs.surrey.sfu.ca:58000/ This http post message tells the back end script to first stop the DVB-H boradcast system and then start the DVB-H boradcast system
• Post-condition: DVB-H broadcast system is up and running with both previous existing videos and the new added video.
• Note: backend script name: /etc/init.d/nsl-dvbh restart

 /etc/init.d/nsl-dvbh <start|stop|restart|status>
 input: HTTP Post message from web browser
 output: a feed back message to indicate whether the DVB-H broadcast system is running
 main function:  launch  rundtplay.sh, runtimeslicer.sh, runproxy.sh, runvlc.sh, and python scripts to start DVB-H boradcast system,  do system kill call to stop DVB-H boradcast system.

User wants to remove an existing video channel from the current playing DVB-H broadcast system

• Pre-conditon1: DVB-H broadcast system is up and running with some programs (>=2 programs)
• User select the video file he or she wants to remove
• User clicks on "Remove from DVB-H" button under DVB-H Parameters tab
• The webpage sends HTTP post message to http://cs-nsl-08.cs.surrey.sfu.ca:68000/ This http post message tells the back end script to kill the vlc process for that specific video file. Other parts of DVB-H boradcast system are not changed
• Post-condition: DVB-H broadcast system is up and running with the selected video channel removed.
• Note: backend script name: killone.pl

 killone.pl API
 input: video file name, multicast ip and port
 output: a feed back message to indicate whether the vlc session is killed or not.
 main function: do a system call to kill a vlc process