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Technical Activity
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WWVi's comments on ARIB BML
World Wide Vision Initiative (WWVi) has studied ARIB STD B-24 "Data Coding
and Transmission Specification for Digital Broadcasting", which was developed
and published by the Association of Radio Industries and Businesses (ARIB).
After studying the specification, which is also known as "BML", we concluded
that it has a number of defects as a public specification. Below are the
points that we believe need to be refined:
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Interoperability with the Internet is not taken into account. Consequently,
the BML browser will not be able to display content in HTML.
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If interoperability should be pursued in the future, the current version
of BML, by nature, has difficulties as described below:
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The character repertoire which is defined to be encoded in an EUC-JP based
character encoding scheme is not clearly defined, and there is no conversion table to and from Unicode. In addition, because JIS X 0201, which substitutes "overline" for "tilda" (~), is assigned for the characters under character point 128, URI will not be resolved properly.
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"Gaiji" which are assigned to the Private Use Area of Unicode can never
be interoperable. It is more appropriate to approach these "gaiji"
by a markup based strategy.
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Integration with other markup language modules will not be possible because
BML does not use a namespace.
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The specification includes ambiguous, and sometimes misleading, description.
It does not even make sense in some definitions:
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No substantial definition for B-XML is given. Judging from circumstantial
information, we reached an understanding that "B-XML is an XML document
that can be converted to BML by an XSL stylesheet, which only uses a subset
of the XSLT commands". No constraint is placed on the source document.
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Although BML 'quotes' a considerable amount of W3C technology, such as
XML, it does not conform to W3C technology. On the contrary, as a similar,
but not identical, specification, it prevents interoperability.
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The specification does not contain sufficient description for understanding
BML, which makes it difficult for possible new entrants to enter the market.
It may be true that most of the reasons for the problems decribed above is that XML and relevant technology were not yet made available
at the time of development. However, if interoperability with the Internet
should ever be considered in the future, these problems need to be removed
at an early stage.
[ This text is translated from the original document in Japanese. ] |
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