Re: [EXI LC comment] tiny profile specification

>EXI specification has a lot of features that can reduce document size.
>However it seems too complex for small embedded devices and I will have
>to implement partial implementation. Of course it will lose
>interoperability. I think additional conformance level or tiny profile
>is useful for small devices and interoperability. Is there plan to
>define like it?

Hello Wataru, thanks for your comments.


The importance of a small footprint has been kept in mind while
developing the EXI format.  The working group has considered the
number and complexity of mandatory features (affecting code size) and
the initial data that must be available to support the format
(affecting initialized data segment size).  Additionally, some of our
members have successful EXI implementation experience in
resource-constrained environments.

We concluded, however, that we should not define different levels of
conformance to accommodate subsets of EXI capability. Defining
the right profiles depends very much upon the use case(s) in mind.
The decision as to what capabilities/features could be omitted
and which should be retained was best left to the user/implementer.
We have tried, though, to make sure that terminology defined in
the specification is rigorous enough to discuss EXI features.  This
should help in discussing what EXI functionality is critical in
a given environment and which are not.

But we still maintain that a conformant EXI processor must implement the EXI
specification in its entirety.  We do understand, however, that there may
be partial implementations of the EXI specification in use.  We want to strongly
caution that any restricted profiles for EXI functionality be used sparingly,
and in closed environments in which all participants are aware of the supported
and unsupported EXI capabilities.  It is also critically important that any
profiles be compatible with an implementation conformant to the EXI spec.
In other words, a standard EXI processor should be able to handle any encoded
document that a given EXI profile implementation generates.

Thanks again,

--mike (on behalf of the EXI WG)


Mike Cokus
The MITRE Corporation
757-896-8553; 757-826-8316 (fax)
903 Enterprise Parkway
Hampton, VA 23666

Received on Wednesday, 8 April 2009 15:01:49 UTC