1609.3 WAVE Codec

Codec for IEEE 1609.3 and 1609.2

1609.3:

• Root PDU is ShortMsgNpdu
• UPER encoded

1609.2:

• Root PDU is Ieee1609Dot2Data or Ieee1609Dot2EncapsulatedWsa
• OER encoded

Quickstart

The converter CLI tool compiled and examples are in the examples folder.

cd examples

The CLI tool was compiled with Clang in WSL Ubuntu.

To decode from a PCAP frame (802.11/radiotap), extract everything after the 0x86DD marker into file ShortMsgData.bin.

To extract UDP from PCAP: Remove the initial byte 01 from the UDP payload, then decode ShortMsgNpdu

To Decode 1609.3 to XML:

./converter-example -p ShortMsgNpdu -iuper -oxer -1 ShortMsgNpdu.bin > ShortMsgNpdu.xml

or to JSON:

./converter-example -p ShortMsgNpdu -iuper -ojer -1 ShortMsgNpdu.bin > ShortMsgNpdu.json

Extract the hex from the body element and convert to bin

jq -r '.body' ShortMsgNpdu.json > ShortMsgNpdu.hex
xxd -r -p ShortMsgNpdu.hex ShortMsgNpdu.bin

Decode 1609.2 via:

./converter-example -p Ieee1609Dot2Data -ioer -ojer ShortMsgData.bin > ShortMsgData.json

or

./converter-example -p Ieee1609Dot2EncapsulatedWsa -ioer -ojer ShortMsgData.bin

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Notes

To compile the converter:

Change the choice field named "NULL" to "NULL_" to avoid conflict with the built-in NULL C macro in:

• Extensions.h
• Extensions.c
• Ieee1609Dot3Wsa_ExtendedChannelInfo.h
• Ieee1609Dot3Wsa_ExtendedChannelInfo.c

Edit the 'protocol.asn' file

Use the workaround from this project: vanetza ETSI C-ITS implementation

to deal with the parameterized "WITH COMPONENTS":

https://github.com/riebl/vanetza/blob/6eb42c644d367a7871705b4e3d27c9f71c435d9d/vanetza/asn1/patches/ieee/Ieeedot2dot1Protocol.patch

Patch file:

asn/1609.3-2020/protocol.patch

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Compile

asn1c -fno-include-deps -fcompound-names-all -gen-OER -fincludes-quoted -pdu=all ../../asn/1609.3-2020/*.asn

or

asn1c -fno-include-deps -fcompound-names-all -gen-OER -fincludes-quoted -pdu=auto ../../asn/1609.3-2020/*.asn

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Build converter with clang

cd generated
export CC=/usr/bin/clang
make -f converter-example.mk

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Logical Link Control EtherType = 0x88DC

EtherTypes: https://standards-oui.ieee.org/ethertype/eth.txt

0x88DC = (WAVE) Short Message Protocol (WSM)

see comment in Wireshark dissector in packet-llc.c:

/* IEEE 1609.3 Ch 5.2.1
 * The LLC sublayer header consists solely of a 2-octet field
* that contains an EtherType that identifies the higher layer protocol...
* Check for 0x86DD too?
*/

0x86DD = Internet Protocol Version 6 (IPV6)

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The 1609.3 specification is from 2020. It depends on and older version of 1609.2 (it doesn't work with the 1609.2-2022 OID)

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E-EUTRA Subset:

The specifications require a subset of definitions from the EUTRA-RRC and EUTRA-Sidelink 3GPP specifications. A script to extract the necessary subset from these specs is provided, which greatly reduces the number of generated files in the codec and the size of the codec executable.