POIM-PA v2.1.1 (Parking Availability)

[Arslan90]

Hello,

Although I am already a User of Vanetza, this is my first contribution to the project. In this PR, I am trying to add POIM-PA messages (version 2.1.1 - Release 2) based on ETSI definitions available here. The submodule TS 103916 v2.1.1 PA (Parking Availability) ASN1 files are copied instead from ETSI repository, due to a missing bug fix.

Also, I patched the ASN1 definitions to:

• Import GeoPosition field from CDD 2.2.1, instead of redefining it
• Define locally the EngineCharacteristics (renamed EngineCharacteristicsFromIso) field to avoid generation of all fields from ISO17573-3-1.asn and potential duplicates/naming collision

Moreover, this PR includes a Guide to explain how to update & regenerate ASN1 structs.

Finally, I used mouse07410 version of ASN1C based on the following commit/code version

Thanks :)

[riebl]

Thanks for your PR @Arslan90, looks pretty good! I think there are just a few things left which have already become obsolete since you have started working on it.

[riebl]

I guess this file should not be part of the PR.

[Arslan90]

Thanks for your positive reply :) Regarding this document, I would say Yes & No, meaning it is quite difficult to know how to generate ASN1 structs due to the different version of ASN1C compilers, and I find it convenient to have such details somewhere else in the project (can be also a subsection of the README file)

[riebl]

I agree, that a small "how to" is useful.
I have to admit, that the integration of asn1c into our build system is a little bit tricky. There are plans to bundle the "right" asn1c version as Docker container.

[Arslan90]

That would be great

[riebl]

Please do not add "dead code"

[Arslan90]

I left that since I don't know which option is best:

1. Avoid using ISO definitions and manually patch the POIM-PA => which is my personal choice
2. Use the ISO definitions directly, although if it has an important impact in terms of redefinitions & naming collision => maybe you prefer this solution

[riebl]

From my past experience I can say that it usually gets messy with these ISO definitions, so I like your first option. It may become necessary to switch to the full ISO definitions in the future if the ETSI ASN.1 files make use of it at a larger scale.

[riebl]

According to the added README, this file is no longer required since you have manually imported the EngineCharacteristics.

[Arslan90]

OK, so I can update my PR according to your latest comments. I will also try to add a subsection dedicated to the ASN1C build system instead of adding a new MD file