Overview of B-XML/BML draft specification developed by ARIB


October 1999

Association of Radio Industiries and Bisinesses (ARIB)

1 Background

- it satisfies the requirements for digital broadcasting and its data broadcasting which have been discussed in the Digital Broadcasting System Committee of the Telecommunications Technology Council.

- it ensures high extensibility which is a feature of the XML based coding scheme and international exchangeability.

- it can also be introduced with the minimum influence on receiver costs from the start of BS digital broadcasting in the year 2000.


The first phase of this standardization which is aiming at the start of BS digital broadcasting will be finalized this October. The second phase of which scope is under consideration will be finalized in March, 2000.



2 Scheme of the draft specification

2.1 B-XML and BML

Figure 1

BML (XML based multimedia application language) and
XML-like application using B-XML scheme


2.2 Scope of XML based coding scheme

Figure 2 depicts protocol stacks of data broadcasting(extraction of the main part)and placement of the draft specification.


Figure 2

Protocol stacks of data broadcasting (extraction) and
placement of this draft specification

Multimedia services which are described using the XML based coding scheme consist of monomedia representation data, such as bitmap, audio, character and graphics, and multimedia representation data which integrate and control the monomedia data. Multimedia documents are described with the format using BML or B-XML. In the case of broadcasting, the contents should be transmitted according to the DSM-CC carousel or the additionally specified transmission scheme by the future extension. Also, it is assumed that the contents may also be provided from the interaction path when they are additional services for broadcasting. Telecommunication control via interaction path is assumed to serve not only the acquisition of the contents but also simple transmission control for sending order and questionnaire from receiver to the computer center.



2.3 Overview of the specification

As shown in table 1, the draft specification developed by ARIB is highly consistent with that of ATSC/DASE.

Table 1

Overview of the draft specification



Application description format

Not fixed. To be considered with JAVA and so on in the future(e.g. phase 2).


Base format


Procedure description language



Presentation control


Extensions for broadcasting use

  • Synchronization with progress of broadcast program
  • Automatic update of presented information
  • Control of video and audio
  • Operational control via remote controller
  • Communication control for interaction path

Application dependent contents description


3 Summary of the BML extensions for broadcast use

3.1 Additional elements and attributes

The following specifications being developed by ARIB take into account the compatibility and consistencies with ATSC/DASE specifications.

3.1.1 Addition to the XHTML extension module

1) Elements and attributes for broadcast event handling

2) Extensions for monomedia presentation(attributes of object element)

3) Special effect can be set when a transition between two documents occurrs (attribute of anchor element).

4) Menu screens which is designed for the use of remote controller operation (both bitmaps and characters can be used for each element).

3.1.2 Addition to the CSS

1) Color space

· YCbCr + α(half transparent) Color space

· Addition of designation of index-color

2) Remote controller operation

· Focus shift control with the operation of the keys such as "up", "down", "left", "right" and "select". (liaison with ATSC/DASE)

3.1.3 Group of ECMAScript functions

· Reservation of a program or serial programs

· Write, read and management of NVRAM

· Telecommunication control for interaction path

· Registration of DRCS (Dynamically Re-definable Character Sets: since the fonts of the characters which are rarely used are not located in the receivers, they should be downloaded for the document where they used.)