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Minutes Webex 15 February 2013, 6TSCH group

Note: timestamps in PST.

Present (alphabetically)

  1. Alfredo Grieco
  2. Gennaro Boggia
  3. Marc Blanchet
  4. Normann Finn
  5. Pascal Thubert
  6. Qin Wang
  7. Raghuram Sudhaakar
  8. Robert Assimiti
  9. Sateesh Addepalli
  10. Thomas Watteyne
  11. Tina Tsou
  12. Tom Phinney
  13. Xavier Vilajosana


  1. [10min] Status/Discussion on draft-watteyne-6tsch-tsch-lln-context
  2. [10min] Other potential early drafts, examples:
    • the 'sublayer' specification (Qin, Xavi, others?)
    • overall architecture document (Pascal, others?)
  3. [30min] Preparing for the bar BOF;
    • [5min] agree on date (Tuesday or Wednesday noon). 5min
    • [10min] bar BOF goals (sponsor?).
    • [15min] List goals, scope, dependencies (liaisons) for a 6TSCH group
  4. [time permitting] misc topics based on ML discussions.


Meeting starts at 09.05 PST

  1. Status/Discussion on draft-watteyne-6tsch-tsch-lln-context
    • [Pascal] asks for status and update
    • [Thomas] 3 open issues on draft:
      • stressing requirements on security in section 3.1 (joining)
      • adding text on deterministic networks
      • extract gotcha: two ways of synchronizing
  2. Other potential early drafts
    • [Pascal] Pascal to start architecture draft
    • [Pascal] second draft about sublayer, started by Qin and Xavi
    • [Normann] Offers to give a quick overview of work on deterministic Ethernet in 802.1 IEEE group.
      • Topology is not spanning tree, but rather IS-IS used to run the network
      • BW reservation scheme
      • time sync scheme based on 1588
      • already work with the 802.11 group to have 802.11 appear as "just another medium", possibly to be used with wireless meshes of APs.
      • Time scheduled transmission
      • Preempting transmission with higher priority frame (not applicable to wireless).
      • working group used to be called Audio Vdeo Group (AVG), name changed to Time Sensitive Networks (TSN)
      • Interested in QoS, especially l3/l2 interaction.
  3. Preparing for the bar BOF
    • [Pascal] We have a draw between Tuesday and Wednesday noon for bar-Bof.
    • [Pascal] Let's hold it on Tuesday, so we can have an extra session of Wednesday noon if needed.
    • [Thomas] Allows us to be right after ROLL.
    • Pascal to e-mail ADs (in particular Ralph) to ask for room
    • [Pascal] Would Marc agree to helf 6tsch group out to run the bar BoF and prepare for a successful BoF?
      • [Marc] Yes.
    • [Pascal] We have 1.5h during bar-BoF. We should try not to dwell too much on technical issues, but rather discuss:
      • goals.
      • scope.
      • dependencies.
    • [Thomas] Let's publicize in ROLL
    • [Marc] we should use same room as ROLL, since meeting right after
    • [Thomas] We can use draft-watteyne-6tsch-tsch-lln-context to list goals.
  4. misc topics based on ML discussions
    • [Thomas] Synchronization:
      • [Thomas] There are two mechanisms: EB and KA messages.
      • [Robert] EB can be used exclusively. Using EBs consumes less power than KA.
      • [Thomas] Let's discuss this on ML.
    • [Thomas] Using time rather than ASN:
      • [Tom] Don't want per se to discuss this in 6tsch context, we can carry on using ASN.
      • [Robert] It's an important discussion to have. Problems comes up in 802.15.4g where multiple modulation/datarate settings cause packet to be very different. If deriving slot length from worst case packet length, this results in lots of bandwidth waste.
      • [Robert] Can be done with extra IE.
      • [Thomas] Let's "keep an eye open" for cases where switching between ASN and time poses a problem, and maybe write up a document which explains how to do so later.
      • [Robert] Agreed.
      • [Tom] Agreed.
    • [Pascal] new "shim" layer draft.
      • [Pascal] this draft needs to contain:
        • the API towards IP
        • the API towards the existing TSCH
        • some text about the data flows
      • [Qin] Have started working on it. Will take those changes into account.
      • [Xavi] Agreed. Will work on the draft in the coming week.

Meeting ends at 10.05 PST