Subject: [6tisch] PAN ID Compression Field

From: José Ángel Miranda <[email-masked]>
Date: Thu, 21 May 2015 18:51:59 +0200

Hi,

We are implementing 802.15.4e and have some doubts about addressing fields.

Looking at the standard ( IEEE802.15.4e ) we have seen that row three
within table 2a ( 5.2.1.1.6 - "  Destination Addressing mode '00' -->
Destination PAN Identifier present" ) is not congruent with row one within
table 3 ( "Addressing mode '00' --> PAN Identifier and address fields are
not present" ).; which one of those is correct? and what should the PAN ID
Compression value be in that specific case?

Best,
Jose.

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From: Tero Kivinen <[email-masked]>
Date: Fri, 22 May 2015 00:43:30 +0300

> We are implementing 802.15.4e and have some doubts about addressing

Everybody has doubts about them, as the PAN ID compression in 4e
messed up things quite a lot...

Before that everything was simple and easy. After that not so much.
Also people who were involved in the 4e work say there is actually
bugs in the table 2a...

> Looking at the standard ( IEEE802.15.4e ) we have seen that row
> three within table 2a ( 5.2.1.1.6 - "  Destination Addressing mode
> '00' --> Destination PAN Identifier present" ) is not congruent with
> row one within table 3 ( "Addressing mode '00' --> PAN Identifier
> and address fields are not present" ).;

Table 2a overrides the table 3. Table 3 gives you the generic rules,
i.e. when it says that in addressing mode 00 there is no pan
identifier nor the addressing fields present, that means that it is so
only if not said otherwise.

The table 2a on row 3 says that if you want to send frame without
source or destination address fields, but want to include destination
PAN id, you set both addressing modes to 00, and set the PAN ID
compression to 1 with frame version 0b10 for Beacon, Data or
Acknowledgement frames (for multipurpose frames the frame version will
be 0b00 even when it says 0b10 for them too in table, as there is no
frame version 0b10 defined for multipurpose frames even).

This frame version field values for multipurpose frames is one of the
bugs in that table, but also there are other issues in the table, i.e.
some of the rows depends also about the address format (short or
extended), not only whether the source or destination addresses are
present.

There is work in progress to fix this table, check out the latest
version of the 15-15-0130 document from mentor to see the progress.

https://mentor.ieee.org/802.15/documents?is_dcn=130&is_group=0mag

> which one of those is correct? and what should the PAN ID

If you are using row 3, then PAN ID compression will be set to 1... 
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