WPAN as innovation?

Werner Almesberger werner at almesberger.net
Sat Apr 9 19:42:59 EDT 2011


jon at rejon.org wrote:
> I have some questions.

I'll pick a few :-)

> Is there a major page about BEN-WPAN?

I think you've answered that one below :-)

> To call this Zigbee, do we have to pay a fee? It is similar to the
> distinction between MESA and OpenGL?

If we called it ZigBee, maybe. But we shouldn't call it ZigBee,
because it isn't ZigBee, not even ZigBee in disguise :-)

IEEE 802.15.4 is an open standard (specifications can be accessed
without royalties, implementations are free from royalties (*))
for PHY and (bits of) MAC. Then you put the rest of your stack on
top. This could be ZigBee, 6LoWPAN, or something else.

(*) Of course, with patents, where could always be issues. The
    standard explicitly warns that

  | Attention is called to the possibility that implementation of this
  | standard may require use of subject matter covered by patent rights.
  | By publication of this standard, no position is taken with respect
  | to the existence or validity of any patent rights in connection
  | therewith. The IEEE shall not be responsible for identifying
  | patents or patent applications for which a license may be required
  | to implement an IEEE standard or for conducting inquiries into the
  | legal validity or scope of those patents that are brought to its
  | attention.

    I don't know if contributors were asked to disclose any patent
    claims.

ZigBee is only royalty-free if not used for commercial purposes,
which makes it incompatible with the GPL and licenses with similar
intent.

The good news about ZigBee is - as various sources assure me - that
it is gradually being replaced by 6LoWPAN. I.e., of the original
ZigBee stack, only the top is preserved, and 6LoWPAN (and IEEE
802.15.4) is used underneath. This basically means that ZigBee is
becoming or has already become irrelevant except for those who
specifically seek ZigBee compatibility.

6LoWPAN is an open standard, specified in RFC4944 and other documents.
Standardization work is still on-going. For the IETF's process
regarding IPR claims, see http://tools.ietf.org/html/bcp79
For claims disclosed with regard to RFC4944, see
https://datatracker.ietf.org/ipr/search/?option=rfc_search&rfc_search=4944

> Is freedom really innovation? As in we have the freedom to make our own WPAN?

I would say that freedom is an enabler for innovation. Remember the
dark age, when the best universities involved in kernel-level research
could do was to obtain a SunOS academic source license, and distribute
their work in the form of precompiled object files ?

> Better argument, since freedom really only works in our FREE circles
> is if we have some argument that described the WPAN as innovative.

IEEE 802.15.4 and 6LoWPAN are also used outside our little circle :-)

E.g., there's the Contiki project (still under an Open license, i.e.,
3-clause BSD) that can provide a code base for 6LoWPAN and maybe some
bits of IEEE 802.15.4 too.

And then there are vendor-specific stacks, etc. You just don't hear
so much about 6LoWPAN because it mainly targets industrial systems
and integrated solutions and is not advertized as a standard for
consumer products.

> Is there an innovation in the software development connected to the
> linux kernel, mesh networking or some other non-process-based
> innovation?

At the moment, no. We don't even have proper support for the stack
in Linux yet, let along in mainline. So there's still a bit of work
left to be done.

> Or, are we caught just doing the same thing that is happening in
> industry,

Before you can overtake the herd, you have to catch up with it ;-)

Not having to start from zero should be a great benefit for any
research/innovation project.

> but without any money?

That is an unfortunate property of the current situation. Luckily,
it's neither a prerequisite, nor has anyone here taken a vow of
poverty. (Let's hope some sponsor reads this :-)

> I'll make a BEN-WPAN page out of it, aka Ben Slowfi. :)

Excellent, thanks a lot !

- Werner




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