Subject: [lp-wan] Outline, SCHC Design Team meeting, December 28th

From: Alexander Pelov <[email-masked]>
Date: Thu, 29 Dec 2016 09:33:55 +0200

Dear all,

At the end of this mail you’ll find the outline of the SCHC Design Team meeting which took place yesterday (December, 28th).

Best,
Alexander

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-- Meeting on December, 28th
  -- Participants: Ana, Laurent, Carsten, Carles, Alexander

- - - - - - - - - -

-- Presentation of the SCHC CoAP draft
  -- Scenarios for the compression
    -- CoAP is complex compared to IP/UDP, we need to determine some of the scenarios for which we want to have most efficient compression
  -- Specifics of LPWANs
    -- Downlink can be triggered by the uplink
    -- The answers may be delayed for huge amounts of time

-- Presentation of the Compression/Decompression functions currently in the draft
  -- Static-mapping (client/server)
  -- Bi-directional mapping between two values
  -- Remapping (server)
  -- Entropy-reduction (server)
  -- Compute-token-length (client/server)

-- Examples
  -- Compression of CoAP return codes to 5 bits (instead of 2 bytes)
  -- Remapping of Message ID 
  -- Entropy reduction 

-- Note: part of the CoAP SCHC functions could be done by a CoAP proxy
  -- May be a useful analogy when explaining the concept

-- Question on context negotiation
  -- Static contexts configured on both sides
  -- See further how this would behave with CoMI

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-- Roadmap for the next calls
  -- Specify scenarios to cover in the CoAP compression
  -- Specify uncompressed CoAP exchanges (covering the scenario)
  -- Specify the rules that we would like to use with these
  -- Show how these rules lead to the compressed exchanges
  -- Show the COMI exchanges that install these rules

-- January, 4th
  -- IPv6/UDP SCHC compression and fragmentation
-- January, 11th
  -- CoAP SCHC compression 
-- January, 18th - SCHC IP/UDP/fragmentation 
-- January, 25th - SCHC CoAP