Re: [Tm-rid] 1st steps - time lines and drafts

[Michael Richardson <[e-mail]>]

Card, Stu <[e-mail]> wrote:
    > I like the generality & extensibility of CBOR, CDDL, COSE, COID, etc.,
    > esp.  as an attempt at future-proofing tm-rid.

So, to be clear: CDDL is a documentation tool. It never travels on the wire.
Some people may be able to generate code from CDDL.  Some people have also
considered how to encode CDDL in... CDDL, which is a meta-meta situation, and
double so, not something to worry about.

COSE, COID are implemented on top of CBOR.
IPv4 and IPv6, DHCP, OSPF, Radius, etc... all include variously (and
differently) encoded "extensions" usually in the form of Type-Length-Value
structures.

    > I wonder, though, whether all their self-describing headers are too
    > much overhead for the severely constrained Bluetooth frames of ASTM's
    > proposed Broadcast Remote ID format.

My experience with CBOR is that unless you want a flat non-extendable
C-struct, and you will ALWAYS need *ALL* of the fields,  odds are that CBOR
is smaller. CBOR probably does better at encoding than many of the TLV
structures mentioned above, but probably the VLSI guys 20 years ago would
have been annoyed with it's non-32-bit alignment.

    > IETF, as latecomers to the aviation community's party, should look
    > closely at what ASTM, FAA, ICAO, et al have already concluded or
    > proposed, rather than regard this as an entirely clean slate; although
    > a truly compelling solution might get them to change some of their
    > thinking, as it has not yet been issued as a standard or implemented by
    > UAS makers (beyond experimentally).

Sure.  Can you point at the documents?

--
]               Never tell me the odds!                 | ipv6 mesh networks [
]   Michael Richardson, Sandelman Software Works        |    IoT architect   [
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Michael Richardson <[e-mail]>, Sandelman Software Works
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