15 selected topics for e-learning technologies (dtv)

Timothy K. Shih

Selected Topics for e-Learning Technologies(Digital TV and MHP)

Digital TV technologies

• Outline– Part1: Introduction to DTV– Part2: DTV receivers– Part3: MHP middleware– Part4: Interactive TV

Introduction to DTV

Introduction to DTV

• Outline– DTV overview– Characteristic of DTV industry– DTV standard overview

DTV overview

• What does DTV mean?– Higher Picture Resolution

• High definition program– Multicasting

• More programs at the same channel and bandwidth– Better Picture Quality

• Less noise– New Type of Broadcasting Service

• Interactions

DTV overview

• Digital receivers– STB v.s. iDTV– STB (Set-top box)

• standalone• Two separate remote control• Cheap products

– iDTV (Integrated DTV)• Integrating STB to TV• STB is a part of DTV• Future trend

DTV overview

• Viewing Experience with DTV– Basic Functions

• Channel Scanning• Channel Organization• Channel Change Banner• Now/Next Information• Parental Guidance• PIP/POP• Teletext, ClosedCaption

DTV overview

• Viewing Experience with DTV (cont’d)– – Advanced Functions

• EPG (Electronic Program Guide)• PVR (Personal Video Recording)• SSU (System Software Update)• PayTV(CA/CI)• Interactive TV (MHP)• Mobile TV

DTV overview

• DTV Basic Functions– Channel Scanning

• Different settings for Satellite/Cable/Terrestrial DTV receivers• Automatically/manually scan

– Channel Organization• Channel list• Channel edit• Favorite list• Sort, delete, hide, …• Lock/unlock channels

DTV overview

• DTV Basic Functions– Channel change banner

• Program name, description• Date/time, duration• HD/SD, Dolby, Aspect ratio,• Parental rating, subtitling

– Now/Next information

DTV overview

• DTV Basic Functions– Parental Guidance

• by program rating• by channel• by time

– PIP & POP• Picture in picture• Picture out picture• One tuner v.s. twin tuners

DTV overview

• DTV Basic Functions– Teletext (TT)

• The users can access text information on TV.

– Closed Caption (CC)• The caption is separated with video frames.• MPEG-II allows different caption streams.

DTV overview

• DTV Advanced Functions– EPG (Electronic Program Guide)

• Displaying program information: name, start time/duration, description.

• Present/Following (now/next) v.s. Scheduled (weekly) EPG

• Display one dimensionally or two dimensionally

DTV overview

• DTV Advanced Functions– PVR (Personal Video Recording)

• Recording• Time-based, EPG-based• One time, periodically

– Playback• Normal, FF, FR, Repeat

– Time shifting– Stream Editing

• DVB-SSU (System Software Update)– Over-the-air software update

DTV overview

• DTV Advanced Functions– PayTV

• The access to services inside TS is• allowed only when subscription

– CA (Conditional Access)• Smart card verification system• Middleware porting is needed• Different STB for different CA providers:• Nagravision, Viaccess, Irdeto, etc.• Cheap but not compatible

DTV overview

• DTV Advanced Functions – CI (Common Interface)

• Common PCMCIA interface for different• CA modules• Same STB for different CA smart cards• Expensive but compatible

DTV overview

• DTV Advanced Functions– MHP (Multimedia Home Platform)

• A middleware• More applications than audio/video• Java-like applications

Characteristic of DTV industry

• Characteristics of DTV Industry– A lot of industries are involved.

• Major components of the DTV system– Content/Service Provider

• TV program, Movie industry, Music industry, Game industry,• information industry,etc.• Digital studio, storage, broadcasting equipments.

– Transmission Channel• Satellite, Cable, terrestrial, fixed/mobile network• Communication equipments

– Terminal devices• TV, Set-Top Box, PC/NB, cellular, PDA, vehicle device, etc.• IC(tuner/decoder/display), Panel, Storage, software, OS, etc.


• Huge difference among different DTV markets– 1. Different DTV standards– 2. Different ecological dispersion– 3. Different market demands


• DTV Standards– ATSC: USA, Canada, Mexico, South Korea– DVB: Europe, Australia, New Zealand,

Taiwan, etc.– ISDB: Japan– DMB-TH: China (2006/8)


• Ecological dispersion (Satellite、 Cable、 Terrestrial)– USA

• 85% users watching cable TV.– Taiwan

• over 85% users watching cable TV– India, Indonesia , middle of Asia:

• Satellite TV– In Europe, Japan and China

• urban : Terrestrial TV• Suburban : Satellite TV


• DTV standards in the world wide


• Market Demands– Picture Quality

• HDTV markets • SDTV markets

– TV Size• Large size of TV• TV smaller than 30”

– Functionality• PayTV

– CA, CI• interactive DTV

– (MHP, OpenCable, …)• PVR• Various customization

– Integration• Integrated with other consumer products, like HDD, DVD.• Popular in Japan, Korea.

DTV Standard Overview

• ATSC standard– Video: MPEG-II MP@HL (main profile, high level)– Audio: MPEG-I layer I,II, Dolby AC-3– System layer: MPEG-ll TS + PSIP– Modulation: 8-VSB (terrestrial), 16-VSB(cable)– Interactive middleware: DASE(old) ACAP(new)

• Main Features– HDTV

• ATSC system supports 18 formats with 6 HDTV, 9 EDTV, 3 SDTV.– Dolby AC-3

• ATSC boasts “theater quality" audio because it uses the Dolby Digital AC3 format to provide 5.1-channel surround sound.

– Low transmission power• VSB requires half transmission power compared with COFDM, so ATSC signal coverage is

larger than DVB-T with same power.• Good for N. America where many places are rural with lower population density.


• DVB standard– Video: MPEG-II MP@ML (main profile, main level)– Audio: MPEG-I layer I, II– System layer: MPEG-ll TS + SI– Modulation: COFDM (DVB-T/H), QAM(DVB-C), QPSK(DVB-S)– Channel Bandwidth: 6/7/8MHz (ATSC 6MHz with fixed 19.39bps)– Interactive middleware: MHP (Multimedia Home Platform)

• Main Features (DVB-T)– SFN (Single Frequency Network):

• Since it is better at handling multipath, same channel freq can be used for adjacent areas. The spectrum allocation is efficient.

– Mobile Reception• Due to Guard Band and the better multipath handling in COFDM, it is good for mobile

reception.– Two-way communication support

• DVB has standardized return channels RCS/C/T to provide bidirectional communication which is good for interactive DTV.


• ISDB standard– Include ISDB-T, ISDB-C, ISDB-S– Video: MPEG-II– Audio: MPEG-II AAC (allows 5.1 audio output)– System Layer: MPEG-ll TS + ARIB STD B-10– Modulation: DPSK, QPSK, QAM, OFDM– Channel Bandwidth: 6MHz (3.7 ~23.2Mbps )

• Main Features– ISDB-S is 1.5 times more efficient than DVB-S. (ISDB-S could

transmit at 51 Mbps with a single transponder, while DVB-S allows at about 34 Mbps)

– ISDB-T has the most flexibility and efficiency for mobile and portable reception, compared with DVB-T and ATSC.


• Mobile TV standards– DVB-H (digital video broadcasting-handheld )

• Derived from DVB-T with improvement on low power consumption, mobile reception, IP data casting.

– T-DMB (digital multimedia broadcasting)• Derived from DAB. Used by South Korea.

– MediaFLO (Media Forward Link Only)• Qualcomm’s technology to broadcast data to portable devices.• FLO means transmission path is one-way, from tower to device.• Verizon Wireless (second-largest wireless network in the U.S.) and Cingular

(merged by AT&T Wireless and become the largest wireless carrier in the U.S. ) announced to deploy MediaFLO in US.

– DVB-SH (digital video broadcasting-Satellite handheld Feb. 2007)• to deliver IP based media content and data to handheld terminals like mobile

phones and PDAs via satellite.


• Profile and level

DTV broadcasting applications• DVB: MP@ML (main profile at main level).• ATSC: MP@HL (main profile at high level).

DTV receivers

What does a DTV receiver do?

• Receives digital TV programs from a cable, satellite or terrestrial network

• Decodes transport streams• Outputs signals to television

– More interactions can be done – Ex. Running applications on STB

Block diagram of a typical receiver

Tuner Front-endSmart card /CA Module

MPEG-2 decoder

CPU

Middleware

SDRAM

Flash memory

Graphics processor

Descrambler

MPEG-2 demultiplexer

The Front End

• Receiver – Converting analog signal to digital one.– Including the tuner and the front end

• The tuner– Receives frequency-specified signal – Demodulates the signal– Turns the analog signal into a digital bitstream

• The front-end– Error correction– Removing packetization in the stream– Outputs an MPEG-2 transport stream

The Demultiplexer

• Decoding information in TS for STB– Elements in the current channel

• Audio and video streams• Broadcast data streams• Service information

– Service information for the network• Passing streams to corresponding components

– Service information and data streams to the CPU – Audio and video to the MPEG decoder

The MPEG Decoder

• Decoding audio and video streams and displaying them on the screen

• Supporting graphical overlays– Cursor, graphics– Some receivers support up to five graphics planes

• Background, video, two graphics planes, cursor• Supporting scaling, clipping and repositioning video

– But this may be limited

The CPU

• Deal with other tasks in the system– Decoding and handling service information– Decoding broadcast data streams– User interaction– Running built-in or downloaded applications

• Often integrated with the MPEG-2 decoder and other components• Typical CPUs

– STMicroelectronics 551x family– NEC EMMA2– ATI Xilleon– Broadcom BCM3560

Conditional access (CA)

• Anti-piracy system for pay-TV– Decrypts data from input streams

• Depending what was encrypted by the network operator– Worked on specified devices

• integrating with the receiver• Smart card or similar device

• Each STB usually has one CA system integrated– This is enough for most pay-TV systems– The box is tied with the subscription, so only used on one network

and one CA system

Conditional Access (CA)

• Some CA systems require special hardware support• Some network operators are now using pure software CA systems

– May still use smart cards for authentication• CA systems may do more than just encryption

– Pair a smart card to a single receiver• Smart card can not be moved to other receivers

– Provide a way of uniquely identifying the receiver • Smart card serial number

– Prevent STBs moving to other household• Second STB • Every household must have their own subscription

Conditional Access (CA)

• Integrated CA systems are unsuitable for some markets• May use a pluggable CA module instead

– Entire decryption solution on a PCMCIA card– Smart card plugs in to PCMCIA card– Used on retail systems to allow use with any network

• This has several limitations– More expensive (PCMCIA card)– Few vertical markets will use pluggable CA modules – Less secure, in the case of DVB-CI

• Not all CA systems will support pluggable modules

Return channel

• Communicating with the network operator or service operator– Ordering pay-per-view services, home shopping, home banking

• May be used for general network access– Web browsing, email, chat

• Many types in use– PSTN modem (usually 56K) – Cable modem and ADSL modem – Exotic technologies such as GSM, DVB RCS (return channel via

satellite) – Not every receiver will have a return channel– The cost is relatively high.– It’s not necessary for all services.

Middleware

• A common software platform for application development– Usually in C or Java– Basic features

• Graphics & video manipulation, return channel access, access to service information, etc.

• Provided middleware platforms today – OpenTV (OpenTV Core)– NDS (NDS Core)– Canal+ (MediaHighway)– PowerTV (PowerTV)– Microsoft (Microsoft TV)– Nagravision-Kudelski (Tsunami)

• Open middleware platforms – MHP, OCAP, ACAP, JavaTV, ARIB-B23

Integration

• Cost is a major factor in STB manufacture– Lots of competition– Typical cost is ~100 USD to the network operator for a standard

STB• Retail is more expensive

• Many components get integrated to save cost– Tuner and front end– Demultiplexer/MPEG decoder/CPU/graphics processor

• Most current STBs are one- or two-chip solutions– Depends on features needed

Block diagram of a typical receiver

TunerSmart card /CA Module

MPEG-2 decoder

CPU

Middleware

SDRAM

Flash memory

Graphics processor

Descrambler


Front-end

Standard STB with pay-TV support (integrated)BOM Cost: ~80 USD

Integrated into front-end

Integrated into CPU

Block diagram of a basic receiver

μController

SDRAM

ROM

Free-to-Air ‘zapper’ boxBOM Cost: ~30-40 USD

MPEG-2 decoder

SDRAM


Tuner / Front-end

MHP middleware

What Is MHP?

• An open standard for interactive digital television• Defined by DVB • Related open standards

– DVB, MPEG, JavaTV

• Providing interactive functionality to develop application

What Is MHP?

• MHP is:– A platform definition– A set of Java APIs– A set of HTML document type definitions– A set of compatibility tests

• It is also:– Compatible with current DVB-based solutions– Freely available (specification available on the web)

• MHP has been adopted in many countries– Germany, Finland, Singapore, Korea, Australia and others– Included in the US OpenCable standard

• Many other broadcasters & content developers working with MHP

What Is MHP?

• Three main standards are related to MHP– MHP 1.0.x (1.0.0 – 1.0.3)

• The original MHP specification plus updates• The most commonly deployed version of MHP

– MHP 1.1.x • Adds some new elements • HTML support, stored applications, Internet client APIs, smart

card APIs• Still a work in progress

– Globally Executable MHP (GEM)• A subset of MHP 1.0.2 • Designed to form the basis of other DTV middleware standards• Currently used by OCAP, ACAP and ARIB B23

Types of MHP Application

• Information services– super teletext, etc.

• Show-related interactivity– online quiz show, online voting, etc.

• Games• T-commerce and banking• Internet access

Building MHP Services

• Applications are built in Java or HTML– Most of products use Java only

• Transported in a DVB transport stream– Transport stream with DVB tables

• Transported in IP connection

What Can An Application Do?

• MHP application can be supported by follow APIs– Most of standard Java APIs – Extensions for TV-specific functionality– APIs for accessing return channel – APIs for controlling and communicating applications

• HTML application support for latest internet standards– XHTML, CSS 2.0, ECMAScript

MHP deployment

• MHP 1.0.2 deployed in:– Finland– Germany– Italy– South Korea

• Other countries will follow soon– Australia, USA (through OCAP)

• MHP 1.1 is not currently deployed– Too many problems remaining– Not enough need for the additional features

• Usually other ways to get what you need

Interactive TV

outline

• Research about interactive TV• The requirements• The proposed system or model• The evaluation or results• conclusion

Research about interactive TV

• Four papers are presented here– Interactive TV: VoD meets the Internet– MiTV: rethinking interactive TV– An integrated live interactive content insertion

system for digital TV commerce– Open graphical framework for interactive TV

The introduction

• Interactive TV: VoD meets the Internet– Shim, S.S.Y.; Yen-Jen Lee;– Computer , Volume: 35 , Issue: 7 , July 2002 – Pages:108 - 109

What is interactive TV?

• Television commerce combines the interactive power of the internet with traditional TV programming.

• Two ways to deliver VoD services:– Focus on TV– Focus on PC

Generic architecture for interactive VoD

• Back-end-service– Video server platform

• Support unicast or multicast at broadband rates.• Consist of a streaming server engine , real-time

streaming file system , etc.

– Security manager• User profiles and usage histories

– Program scheduler• Responding to user interaction

Generic architecture for interactive VoD (cont’d)

• Database– To store metadata and are used on video retrieval.

• Service applications– E-commerce transaction– Messaging platform


• Client platform– There are various device to present multimedia

stream to client side.– Web-based management and rendering

applications can reside in an STB , a PC or a PDA.

– The details will be discussed in the next section.


The generic interactive architecture

Combining other devices to interactive TV

• MiTV: rethinking interactive TV– Bing, J.; Dubreuil, J.; Espanol, J.; Julia, L.; Lee,

M.; Loyer, M.; Serghine, M.;– Virtual Systems and Multimedia, 2001.

Proceedings. Seventh International Conference on , 25-27 Oct. 2001

– Pages:365 - 369

Traditional interface for iTV

• The shortage of traditional iTV– When Interactive event happened , the audience

can not carry on browsing the original program.– Co-watchers– Feedback

• Answering questions

– Entering data• No suitable devices

A new interaction paradigm

• A natural device that comes with the TV is its remote.

• The switch mode is efficient for TV with 100+ channel (change channels by forward and back ).

• Using mobile devices like PDA or tablet to replace remote control may be a better way.

The foundations

• The CAB (Collaobrative Architecture of BravoBrava! )infrastructure.

• It’s used for established communications between the mobile devices and interactive TV.

• Based on Microsoft’s DCOM architectures.

Applications of MiTV

• TV guide on pocket PC

Applications of MiTV (cont’d)

• TV guide on a tablet

The pop-up information

• Showing logos on mobile devices instead of on screen can keep the completeness of view area.

Some examples of interactive TV games

• The audience can join a interactive TV game by receiving information and sending their answers by tablet or PDA.

Some examples of interactive TV games (cont’d)

• Using hand-writing to answer quiz.

Example of an interactive game meant for kids

Example of TV shopping

The third part

• An integrated live interactive content insertion system for digital TV commerce– Liang-Jie Zhang; Jen-Yao Chung; Lurng-Kuo

Liu; Lipscomb, J.S.; Qun Zhou;– Multimedia Software Engineering, 2002.

Proceedings. Fourth International Symposium on , 11-13 Dec. 2002

– Pages:286 - 293

introduction

• MPEG-2 is the video format used in digital TV. there are three types of digital TV formats:– ATSC

• Advanced television systems committee scheme – DVB

• Digital video broadcast– ARIB

• Association of radio industries an business

Introduction (cont’d)

• The problem of effectively organize the interactive content and deliver its data in a timely fashion to an mpeg-2 data injector.

• This paper proposed an improved method for inserting interactive content into a live TV.

Digital TV commerce solution

• Interactive solution

System architecture of the integrated system for live data insertion

• System architecture

Software based implementation flow

• Dataflow diagram

The HotMedia TV Live

Interactive content creation engine (ICCE)

• The authors provide an ICCE engine to convert the online product list on the e-commerce server.

• And combine some control (java script) to the web part in interactive TV.

Interactive content creation engine (cont’d)

• A sample of the converted HTML

Scheduling

• Time-action mapping list– 10/10/2000, 10:21:30, 3– 10/10/2000, 10:40:30, 5

• Event-action mapping list– PROGRAM_START, 5– PROGRAM_END, 4– COMMERCIAL_END, 3– COMMERCIAL_START, 4

The final part

• Open graphical framework for interactive TV– Cesar, P.; Vierinen, J.; Vuorimaa, P.;– Multimedia Software Engineering, 2003.

Proceedings. Fifth International Symposium on , 10-12 Dec. 2003

– Pages:21 - 28

introduction

• This paper focus on development of framework and emphasize on cross platform

• So they choose JAVA for implementation and Linux platform for performance.

System architecture requirements

• User experience

• Developer experience

• Core architecture

• Adaptability

Classic architecture

• User Interface software components

Evaluation themes

• Here are some interesting terms they defined to evaluate UI software tools.– Focus – threshold– Ceiling– Path of least resistance

The digital television standard

• Various DVB , they are popular in Europe– DVB-S (satellite)– DVB-T (terrestrial)– DVB-C (cable)– DVB-MHP (multimedia home platform )

The architecture models

• Graphical architecture model and MHP setup

The proposed system

• Navigator application

The proposed system (cont’d)

• Teletext application

The proposed system (cont’d)

• SMIL television application

Summary

15 selected topics for e-learning technologies (dtv)

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