Subject: [6tisch] Questions about 6tisch tsch draft

From: Ines Robles <[email-masked]>
Date: Thu, 25 Sep 2014 01:06:00 +0300

Hi,

I have some questions:

1- related with draft-ietf-6tisch-tsch-01:

        1.a-  in A.1 Timeslots, states: "The duration of a timeslot is not
defined by the standard". The 802.15.4e standard defines in page 176 the
field:

macTsTimeslotLength

Range:  0x0000– 0xffff

The total length of the timeslot including any  unused time after frame
transmission and Acknowledgment, in μs

default:  10000 = (10 ms)

and it is mentioned as well in the minimal draft.(page 7)

          1.b- In the same section  states: "...with a 10 ms slot (a
typical duration)", would be good maybe if it is added for example the
amount of khz for these 10 ms, like "10 ms is a typical duration for a
quartz crystal of  32.768 kHz"?

             1.c -  In A.11 states: "..EB frames are sent on all
frequencies.  A mote wishing to join the network listens for EBs....",
maybe would be good to add in some way that:

            1.c.1 -  EB are sent on all frequencies if CONFIGURE.eb
(channelOffset) = 0 (pag 25 6top-sublayer draft), right?

            1.c.2 - a mote listens in all the frequencies as well, until
find a EB with the low join priority (of a PAN Coordinator is zero - pag.
90 of 15.4e)

or explain a little this part of the standard: "When a new device wants to
join a network, it uses the MLME SCAN.request primitive in order to
initiate a channel scan over a given list of channels. It searches for all
coordinators transmitting enhanced beacon frames within the maximum BI
period ". pag 48 of the Standard, it is for DSME, but I think it applies as
well for TSCH.  Just to clarify which is the first channel which the mote
listen for EBs.  I think a mote start in channel 11 until channel 26.

2- when a mote join to the network in which slot of the slotframe cames the
EB. In the ietf-minimal draft version 00 states: "The first slot in the
slotframe is used to send Enhanced Beacons announcing the presence of the
network" and in the figure (pag. 4) was used the first slot of the channel
0. It was deleted in the next versions, since it depends of the
configuration that 6top does using CONFIGURE.eb - slotOffset (the
slotOffset where the EBs must be sent. Zero if any Any timeslot can be
used). so, in this case (slotOffset=0 and channelOffset=0 ) a joining node
starts listen in all the channels until find a EB in some slot. right?

3- Related to PHY-FH (page 202/203 of 15.4e) [
http://www.ietf.org/mail-archive/web/6tisch/current/msg01753.html] , in
case that it were not complex,  should be 6top the layer to handle PHY-FH ?

Thank you very much in advance,

Ines.