DVB standard detailed introduction

DVB standard detailed introduction

1. Development principles and processes
The DVB standard is published by the European Telecommunications Standards Association (ETSI, European TelecommunicaTIons Standards), and there is almost daily collaboration between the two organizations. ETSI, CENELEC (Centre for Electrotechnical Standards) and EBU (European BroadcasTIng Union) have established a joint technical committee (JTC) to deal with the DVB standard family.

(1) Development of DVB standard

The Commercial Module compiles a series of User Requirements for each specification. They are constraints on the norm. User demand outlines market parameters (price range, user functions, etc.) for a DVB system. The technical module (Technical Module) then develops specifications according to these user needs. The approval process within DVB requires the commercial module to be able to support the specification before it is finally approved by the Steering Board. After being approved by the steering committee, the DVB specification shall be provided to relevant international standard entities (ETSI or CENELEC), ITU-R, ITU-T and digital audio through the EBU / ETSI / CENELEC JTC (Joint Technical Committee). The Video Committee (DAVIC) standardizes.

(2) DVB standardization principles

The following principles are the characteristics of the standardization efforts of the DVB project:

l Openness

The DVB system was developed with the unanimous consent of the Technical Module Working Group. The members of the working group are elected through the engineering committee meeting. Once the standards are published on ETSI (http: //), they are nominally available to everyone. Open standards allow manufacturing and broadcast companies to implement innovative and value-added services. The application of DVB technology has spread to the world.

l Interoperability

Because the DVB standard is open, all manufacturers who produce systems consistent with this standard can ensure that their DVB equipment and DVB equipment of other manufacturers work together, which increases the intrinsic value of CE equipment for consumers. In addition, due to the utmost consideration of versatility when designing standards, and based on the universal MPEG-2 encoding system, they can be transmitted from one medium to another without difficulty, which has a complex distribution today. It is a common thing in a global environment. DVB signal can be easily transmitted from satellite to cable, cable to land and consumer equipment, and it does not cost much.

l Flexibility

Because MPEG-2 packets are used as "data containers" and key DVB service information is used to encapsulate and identify these packets, DVB can be delivered to almost everything that can be digitized at home, whether it is high-resolution TV, multi-channel standard resolution TV (PAL, NTSC or SECAM), or even new exciting broadband multimedia data and interactive services provided by the DVB multimedia home platform.

l Motivation to lead the market

Compared with the earlier motives in Europe and America, the DVB project was carried out in accordance with strict business requirements, which were established by organizations dedicated to meeting this demand every day. It is not a motive (top-down) driven by managers or governments. Acting on strict time standards and strict market demand means that a considerable economic scale can be achieved, which will ensure that in the process of industrial to digital transformation, radio stations, manufacturers and the public will benefit from it.

2. Main contents of DVB standard (1) Standard classification

According to the scope of facilities involved, it can be divided into two parts: infrastructure and information structure.

1. Infrastructure / Transmission

(1) Broadcast transmission (satellite, cable, land, ...);

(2) Service Information (SI, Service InformaTIon);

(3) The return path of interactive services.

2. Information structure / middleware

Mainly a multimedia home platform, including API (application programming interface).

According to the processing object, it can be divided into:

l Audio (audio

)

l Conditional access (CA, condiTIonal access

)

l Operation guide (cookbook

)

l Interaction

l Interface technology (interfacing

)

l Measurement standard

)

l Multimedia home platform (mhp)

l Multiplexing

l Sub-titling

l Transmission

(2) Standard description

Audio

DVB is basically based on the MPEG-2 system. Therefore, audio inherits the recommended standards for stereo and surround sound in MPEG-2. However, MPEG-2 audio is specified in ISO / IEC13818-3, and TR 101 154 specifies the minimum requirements for baseline receiver interoperability. Sometimes, radio stations may prefer to use Solby AC-3 audio for surround sound. The choice of this implementation is described in TR 101 154, TR 101 211, and EN 300 468.

2. Conditional access

Conditional access is not completely formulated in DVB, but a series of tools enable DVB users to propose the most practical and efficient mechanism for their market. For the entire "DVB CA package", the key is the DVB Common Scrambling Algorithm (CSA, Common Scrambling Algorithm), which is available for ETSI.

In DVB, there are two CA interoperability schemes:

lSimulCrypt. In this mechanism, a single transport stream can contain several CA systems, which will help different CA decoding programs (possibly install different CA systems) to receive and correctly decode the same video and audio streams.

lMulticrypt. Around the parsing of the public interface specification, this public interface allows users to manually exchange between CA systems when installed in a set-top box or TV. Therefore, when the viewer is faced with a CA system that is not installed in his box, he simply exchanges cards.

About DVB standard

:

DVB-CS

DVB-SIM

3. Operation guide

For such a set of complex specifications and standards covering all digital TV fields, from pure video and audio transmission on a large number of transmission media to complex interactive media applications, it is necessary to give a comprehensive guide. DVB's "Operation Guide" is such a guide.

DVB-Guide

4. Interaction

Since the birth of DVB, interactive applications have been considered the cornerstone of a new generation of digital TV. DVB has divided its interactive service package into a set of network independent protocols and a series of specific media return channel specifications.

For example, DVB-Return Channel Through Cable Specification (DVB-RCC) is the product of a long-term cooperation between DVB and Digital Audio Video Interactive Council (DAVIC, Digital Audio Video Interactive Council). It provides a method in which Interactive services can be achieved on a cable network with a bidirectional bit rate of 3 Mbit / s. Traditional telephone interactive functions and more complex satellite interactive systems also have corresponding specifications.

About DVB standard

:

DVB-NIP

DVB-RCC

DVB-RCCS

DVB-RCD

DVB-RCG

DVB-RCL

DVB-RCP

DVB-RCS

5. Interface technology

The key to any TV system is interoperability, which is especially important in the digital age. Interface technology is the key to this field. DVB provides a range of interface options for professionals, IRDs, and conditional access applications. DVB professional interface (EN 50083-9) can be divided into parallel and asynchronous serial interfaces. The IRD interface (EN 50221) includes a set of standard interfaces, which are used on DVB set-top boxes (such as RS-232), video connections, SCART, etc. Finally, the DVB universal interface (EN 50201), based on a PCMCIA connector, is the key to the Multicrypt conditional access scheme.

About DVB standard

:

DVB-ATM

DVB-CI

DVB-HAN

DVB-HLN

DVB-IRDI

DVB-PDH

DVB-PI

DVB-SDH

6. Measurement

ETR 290 is one of the most important DVB specifications. It outlines the measurement technology outline and is compatible with DVB / MPEG transport streams and satellite, cable and terrestrial transmission systems. It is the foundation of many measurement equipment and one of the keys to the successful realization of DVB's inclusion of multi-vendor equipment.

A set of documents exists, and DVB often monitors their implementation and the generation of new standards to ensure the existence and implementation of appropriate measurement guidelines.

DVB standards include:

DVB-M

7. Multimedia home platform

Multimedia Home Platform (MHP, Multimedia Home Platform) is a series of measures designed to achieve a harmonious transition from analog TV to digital interactive multimedia in the future. MHP is based on a series of Java Application Programming Interfaces (APIs, Application Programming Interfaces) for DVB set-top boxes, allowing a home platform to facilitate integration.

There are more than 100 pages of MHP that define application lifetime, security, and data download mechanisms for enhanced broadcasting, interaction, and truly complete Internet applications.

DVB standards include:

DVB-MHP

8. Multiplexing

MPEG-2 is the foundation of DVB video, audio and transmission. However, the MPEG-2 specification does not provide all the information needed to ensure interoperability, data broadcasting, and true dispatch delivery in a television system. Therefore, DVB defines a set of guidelines for implementing MPEG-2 in DVB (TR 101 154), covering the minimum requirements for interoperability of baseline SDTV, HDTV and professional DVB IRD.

In addition, DVB has extended the MPEG-2 system specification (ISO / IEC 13818-1) to become a complete Service Information specification (DVB-SI).

Data broadcasting is a key application of digital TV. DVB uses the elements of MPEG-2 Digital Storage Media-Command and Control (DSM-CC, Digital Storage Media-Command and Control) and has produced specifications and guidelines. These are now the world ’s The basis of most data broadcasting applications.

DVB standards include:

DVB-DATA

DVB-MPEG

DVB-SI

DVB-TXT

DVB-VBI

9. Subtitling

The DVB subtitle specification is a bit-mapped subtitle system that can carry much more complex information than analog systems, such as bitmapped logos. It supports all widely used languages ​​and is the cornerstone of many digital TV applications in the world.

DVB standards include:

DVB-SUB

10. Transmission

The core of the DVB system is its series of transmission specifications. The first specification is DVB-S, the DVB satellite transmission standard, based on QPSK, which is now the de facto digital TV application world satellite transmission standard. DVB-C, the cable delivery mechanism (cable delivery), is closely related to DVB-S, is based on 64-QAM, and of course supports higher-order modulation schemes.

DVB-T (terrestrial transmission) is the youngest of the three core systems of DVB. It is based on COFDM (Coded Orthogonal Frequency Division Multiplexing) and QPSK, 16 QAM and 64 QAM, and is the most complex and flexible digital terrestrial transmission system available today. DVB-T allows service providers to match or even improve the coverage of analog TV without much effort. It extends the scope of digital terrestrial television to the mobile field (which was previously considered impossible!), Or to integrate with other digital systems.

Associated with these three core standards is a set of implementation guidelines and document plans designed for microwave digital TV submission.

DVB standards include:

DVB-C

DVB-DSNG

DVB-MC