Re: [802.21] [Mipshop] Re: Architectural Considerations for Handover InformationServices (was: Re: CARD Discussion Query Discussion)
On Mon, Oct 17, 2005 at 08:14:10AM +0200, Hong-Yon Lach wrote:
> >
> > I am claiming that if Solution 1 that provides less semantic query
> > (one may call it simple query) needs to carry x1 bytes of actual
> > information with its encoding overhead o1 bytes, while Solution 2 that
> > provides more semantic query (one may call it complex query) needs to
> > carry x2 (<x1) bytes of actual information with its encoding overhead
> > o2 (> o1) bytes, to make the same handover decision, then what we need
> > to compare in terms of information volume is [x1+o1 vs. x2+o2],
> > instead of [x1 vs. x2] or [o1 vs. o2]. And when we are discussing
> > information encoding, we are just discussing [o1 vs. o2], and choosing
> > a solution based only on this factor is wrong.
> >
> > If we view Solution 1 as TLV-based and Solution 2 as XML-based, then I
> > think [x1 > x2] && [o1 < o2], and depending on how we encode XML,
> > diffence between o1 and o2 can be small.
> >
>
> [hong-yon] I think your analysis is misleading. First of all, why semantic
> query cannot be carried out with TLV encoding? TLV has been used to convey
> flexible payloads, which can be of different combination of information
> elements. One example is the optional fields; another is that different
> information elements have their identifiers to allow them to be flexibly
> selected for exchange on a per-need (semantic) basis. Thus, there is no
> reason that x1 and x2 are different! Besides, in the overheads, there is
> more than just information encoding, there is also the information
> structure.
I think if someone comes up with a complete solution that uses
TLV-encoding and also supports semantic query, that could be the best
solution. In fact I have been thinking about such a solution, but it
is just hard for me to come up (probably it is as hard as writing an
application program in assembly language). Just having information
element identifiers is not sufficient for semantic query.
Relationship among information elements also needs to be defined and
utilized for semantic query, and that is why schema is defined in
802.21.
Regards,
Yoshihiro Ohba