Pascal Thubert (pthubert) writes: > IEEE 802.5.4 understood and started addressing those issues in their > protocols years ago, consider for instance how this is done at PHY > layer in 802.15.4K LECIM - LP-WAN (cc'ing Pat). In the light of that > art, the legacy 6LoWPAN technique is shamefully inadequate.
802.15.4k is really only a phy level fragmentation, and the main issue there is that the max packet size in that PHY is extremely small (less than 30 octets). When designing the IEEE std 802.15.9 we checked 4k that and realized that it is not something that can be used in general case, and thats why the MAC level fragmentation in the 802.15.9 is using different method. Fragmentation was needed in the 802.15.9 as KMP payloads do not fit to the small frames of 802.15.4. This fragmentation method (and the multiplexing) from the 802.15.9 will most likely be adopted in the 802.15.12 later... Btw, the 802.15.9 is now available using the get IEEE 802 program, and you can download it from http://standards.ieee.org/getieee802/download/802.15.9-2016.pdf The fragmentation wire formats are described in the section 7, and state matchines are described in section 9. > My suggestion to the group is to take a holistic view of these > issues, and redesign or fragment support. This is what my draft > does. The 802.15.9 is hop by hop fragmentation, so if you want to be able to forward fragments, you need to specify your own way of doing that... -- [email protected] _______________________________________________ 6tisch mailing list [email protected] https://www.ietf.org/mailman/listinfo/6tisch
