DMR TIER 1/2

[alwinhb]

I could see that this repository is precisely for TIER 3. I need to check for Tier 1 and Tier 2 level implementation @kantooon

[kantooon]

Well, sure, you can check, but I think the README is pretty clear on the purpose of this code.

[alwinhb]

@kantooon Thanks Adrian for the help can you share some references for Tier 2 DMR source code(s)?

That can be executed.

[kantooon]

MMDVMHost and MMDVM by G4KLX implement Tier 2.
https://github.com/g4klx/

[alwinhb]

@kantooon thanks for the quick response, But MMDVM is quite wide I am only looking for DMR ( Tier 2 ) Specific source code.

[kantooon]

Well, unfortunately MMDVM is the only open source implementation I know about.

[alwinhb]

@kantooon Any references for 32 bit crc for DMR Protocol

[alwinhb]

It isn't there on my Git, I can use the existing code, If you can confirm the usage of functions

crc32_update - To add 32 bit CRC
finalize - To validate the CRC created with crc32_update function.

[kantooon]

Ok, I understand. That's not a problem, but I can't provide free support for a non open-source project. You can hire me as a consultant though, contact me privately if you want to discuss fees and contract details.

[alwinhb]

Can you help me with your email to discuss further?

I just need understanding on the usage of these two functions - crc32_update and finalize

[kantooon]

Ok, fine, to me it looks like you're in over your head if you have to ask that, but here goes.

You're supposed to call crc_init() first to initialize the value, but here that won't actually do anything since there is no initial remainder. crc_update() must be called with blocks of data of known length, maybe in a loop if the data is split into multiple blocks. FInally, call crc_finalize() to compute the final value, including the DMR specific byte rearanging. You can find more details in annex B.3.9 32-bit CRC calculation of TS 102 361-1.

[alwinhb]

@kantooon Thanks for the explanation! Can you help me with your email address as well, Good to hear that you can help as a consultant/support for the tech projects.

[alwinhb]

@kantooon Can you guide me with Golay 8-20. Algorithm. If I provide the input to file. I am not getting 20 bits output as expected. May be I am missing something on it.