Hi Qin

Yes, the Frame Pending flag is defined as follow:

IEEE 802.15.4-2006 section 7.2.1.1.3
“Frame Pending subfield is 1 bit in length and shall be set to one if the 
device sending the frame has more data for the recipient. This subfield shall 
be set to zero otherwise”

This feature can be especially useful for the upstream traffic in a RPL DODAG. 
In a scenario where a DAG parent have dozens of children, dedicated timeslot 
will be infrequent and share timeslots suffer from contention. If a subset of 
these children have ongoing traffic, the parent can use the Frame Pending flag 
information to schedule temporary soft cells and avoid contention or speedup 
transfer.

[cid:[email protected]]

[cid:[email protected]]

Michel Veillette
System Architecture Director
Trilliant Inc.
Tel: 450-375-0556 ext. 237
[email protected]<mailto:[email protected]>
www.trilliantinc.com<http://www.trilliantinc.com/>



From: Qin Wang [mailto:[email protected]]
Sent: 1 juillet 2015 11:28
To: Nicola Accettura; Michel Veillette
Cc: [email protected]; [email protected]
Subject: Re: [6tisch] draft-dujovne-6tisch-on-the-fly-05

Hi Michel and Nicola,

I think Michel's idea is interesting. But, according to my understanding, the 
Frame Pending setting just means there is frame following, does not mean that 
the current bandwidth provided by TSCH schedule, including hard cells and soft 
cells, is not enough to convey those frames, and then needs more bandwidth 
(e.g. additional soft cells) . Right? Do I miss something?

Thanks
Qin


On Wednesday, July 1, 2015 4:03 AM, Nicola Accettura 
<[email protected]<mailto:[email protected]>> wrote:

Hi Michel,
your proposal is very interesting.

However, OTF does not allocate cells directly: it just computes the estimated 
number of cells to add or delete into the schedule, and then sends this 
information to 6top. 6top is then in charge of negotiating cells among 
neighbors, and meybe perform the scheme you are proposing.

So, your proposal seems fitting more the 6top-to-6top communication.
Am I missing something? What others think about?
Sincerely
Nicola

2015-06-30 8:13 GMT-07:00 Michel Veillette 
<[email protected]<mailto:[email protected]>>:
Hi Diego

It’s my first reading of the “6TiSCH On-the-Fly Scheduling” (and I’m not 
completely done yet) and I wandering if the concept of on the fly, in a single 
exchange, temporary allocation of a soft cell have already been discussed. For 
example, a node can use the Frame Pending subfield (IEEE 802.15.4-2006 section 
7.2.1.1.3) to indicate the presence of packets ready to be transmitted. Based 
on that knowledge, the target may add an IE in an enhanced acknowledgment to 
allocate a temporary soft cell (e.g. single cell). Each subsequent transmission 
may further re-allocate a temporary soft cell. It’s important to note that the 
default delay for a TSCH Acknowledgment is 1ms (macTsTxAckDelay) which seem 
sufficient for the processing of this new IE.



This scheme is very reactive and may help dealing with non-predictable 
communication patterns.
What do you things?


Michel Veillette
System Architecture Director
Trilliant Inc.
Tel: 450-375-0556 ext. 237
[email protected]<mailto:[email protected]>
www.trilliantinc.com<http://www.trilliantinc.com/>




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