Re: [6lowpan] Does the 6lowpan WG want to close?

"Benjamin A. Rolfe" <> Mon, 18 June 2012 18:56 UTC

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Date: Mon, 18 Jun 2012 11:56:30 -0700
From: "Benjamin A. Rolfe" <>
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Subject: Re: [6lowpan] Does the 6lowpan WG want to close?
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I'm not an expert on 802.15.7, although I did read the draft when it was 
It doesn't exactly "re-use" the802.15.4 MAC it seems fair to say it 
borrows substantially ;-).  I'm not really sure what might be going on 
outside of 802.15 with respect to higher layer adaptations, 
implementations, conformance procedures, certification, etc.  A quick 
look at
will give you some idea who contributed which is often a clue as to who 
cares the most ;-).

There has been quite a lot of activity in 802.15 over the last few 
years, with a lot of it focused on 802.15.4.  There are now 3 published 
amendments which add a variety of new PHYs to choose from, and a lot of 
added MAC capabilities (I would think 802.15.4e-2012 would be of 
interest to many on this group).  While no specification or advice is 
given in the standard regarding IP implementations, knowledge that many 
people are and will be running IP layers on top of 15.4 definitely has 
influenced the work of recent task groups.

I too am interested in how visible light can be used to form mesh 
topologies, but haven't done much more than wonder - can't wait to hear 
more informed opinions!

Hope that helps some.


> On Jun 18, 2012, at 20:09, Benjamin A. Rolfe wrote:
>> There are no ongoing projects to amend 802.15.7 at this time.
> Thanks Ben.
> So is there any other activity for getting IP going on top of Li-Fi?
> A quick check seems to indicate:
> -- as this re-uses 802.15.4's MAC, they'd need something like our dispatch scheme.
> -- fragmentation is needed for PHY 1 (PHY frame size limited to 1023 B), not for the higher ones.
> -- HC would probably help with the slower PHY 1, not so much with the faster ones.
> Which of the PHYs is actually real?
> Whether the 6LoWPAN network model (and thus 6LoWPAN-ND) fits is not clear to me -- much of Li-Fi's use will be unidirectional, as a fill-in for some other connectivity, and there will be a lot of star topology usage (see page 6).  Mesh forwarding (route-over/-under) usage appears less obvious to me.
> Of course, the most important question is whether there are people interested in doing the work.
> If there is energy and a clear objective, we will find a way to make this happen (in whatever WG the IETF chooses to do this).
> Grüße, Carsten