Tool to Calculate WACN & System ID or Call Sign

[W6IFA]

I found a great tool to calculate WACN and System ID based on Call Signs.
I had found Eric's tool but it only went one way - WACN and System to Call.
I was looking for a simple way to put in a Call and generate the WACN and System; the spec is a bit confusing to say the least.. I finally found a single tool that converts to and from and includes a tool for SNE based setup too. It is on the right side of this page marked "P25 Calculator".
Cisco IP Interoperability and Collaboration System (IPICS) - Cisco Systems
A Project 25 tool from, of all places, Cisco.

 

[greenthumb]

Good find - Harris uses this methodology to compute unique WACN IDs. They don't use that for system IDs though. The output of this tool is a decimal ID.

 

[GTR8000]

Nice tool, it will even show you the system manufacturer.

The trick is that you have to convert between DEC and HEX. The Cisco tool uses DEC for both the SysID and WACN, whereas we use HEX notation on these systems.

 

[Jay911]

I made a quick little spreadsheet to do this ages ago when I first discovered Eric's calculation webpage. It's relatively simple to go in either direction. Unfortunately I saved it in OpenDocument format back when I was using OpenOffice for all my spreadsheets, and in Microsoft's brilliance, they convert all calculations to values when Excel opens an ODS file.

I'm trying to use an online service to convert it, but it may take until I get home tonight (roughly 8 hours from now) before I can post it. EDIT: Should be attached to this message. Don't forget to unzip it.

If only one could understand the rationale behind what the vendor chooses for the "callsign" when they don't use an actual callsign. For example, one system near me uses A?COEL, which is close enough to the system owner, ATCO Electric, for it to make sense (I suspect they screwed up trying to make ATCOEL, or perhaps 09635-E94 is unavailable or invalid). A different vendor's (Harris) system, however, has PMDL4K, which is not even remotely close to a callsign nor a meaningful acronym or abbreviation relating to the system.

The US federal systems and a number of others have at least partially relevant "callsigns" - the WACN part is involved in making an acronym, but the SID is not. One such example is National Capital Region - WACN 580A0 equates to "NCR" as the first three characters of the "callsign", and the various SIDs make random nonsense characters for the last three.

I never explored, or perhaps I ignored (glazed over?), the SNE portion of the encoding/decoding. Let me see if I can't incorporate that into the spreadsheet now.

 

[Jay911]

Here's a new version that calculates Callsign to WACN/SID (and SNE if valid); SNE to WACN/SID (and Callsign); and WACN/SID to Callsign (and SNE if valid).

I put all the P25 systems in the RRDB in the WACN/SID to callsign page, to demonstrate it.

I question the correctness of the calculation that derives manufacturer code (SNE) from the WACN. As you can see, BEE00 invariably comes up as mfr code D0 (ADI) when it should be 90 (Mot). The reciprocal calculation converts 90 into BEE00; D0 should be C0600. I think the calculation for SNE in the below code snippet (from "WACNguide010406.doc") is wrong, but my brain is too fried to figure out how to correct it right now:

IF INT(N1/1600) = 30
THEN
SNE   = MOD(INT(N1/6),256)
SNESD = MOD(N1,6)
ELSE
The first triplet is a call sign and the process given in clause 4.5.2 will yield the call sign characters.

 

[W6IFA]

P25 Calculator to be improved

I made contact with the guy who wrote the tool on the Cisco site.
He appreciated the feedback and said he would add HEX and DEC to the next version so you would not have to convert.
He also said he knows exactly where the Excel sheet is failing.
Jim911, he said something about the spec not saying it but you need to (subtract?) 4096 before you calculate the number. He also was wondering where you got the additional mfgr. ID's since they are not in the TIA spec. If your numbers are authoritative, he would like to use them.

 

[Jay911]

I presume you mean me there..

Another poster indicated subtracting 64 from the result would achieve the proper mfid, which is what I came up with as well - just don't have any data to test it on anything but Motorola systems (no other WACN I've come across gives SNE data, except BEExx).

The TIA spec does list the other MFIDs but it's kind of roundabout to get to them. TIA-102-AABC-C (the main spec for P25 trunking) refers the reader to TIA-102-BAAC-A, which is now TIA-102-BAAC-C. That document, in turn, says "00 and 01 are 'standard P25', see 'MFID Manufacturers Identifier Number Assignment Guide and Procedures (July 2008)' for others". Despite searches on the TIA web site, I can't come up with the July 2008 version, but a January 1999 version is available at http://ftp.tiaonline.org/tr-8/TR-8.15/Public/_Superseded_Versions/mfid0119a.pdf ... and an October 2007 version at http://ftp.tiaonline.org/tr-8/TR-8.15/Public/MFID_Assignments_080723.doc.

 

[Jay911]

Here's version 3 of my spreadsheet based decoder. MFID calculation fixed and added a couple of MFIDs found in that Oct 2007 version mentioned above; also, made it look a little nicer by masking the #N/A on empty rows.

 

[cvv]

Calculating MFID

Jay911:

I'm the guy W6IFA mentioned.

First, thanks for the pointers to the publications of assigned MFID's.

As for calculating the MFID, the earlier posting wasn't correct. I suggested subtracting 48,000, but that was from N1 and prior to dividing by 6. The suggestion the other poster also works because you're subtracting it at the end of all the other calculations and MOD(INT(48000/6), 256) = 64. Does that make sense?

Anyway, thanks again for the other MFID's and I'll get a new version up that supports hexadecimal shortly.

I presume you mean me there..

Another poster indicated subtracting 64 from the result would achieve the proper mfid, which is what I came up with as well - just don't have any data to test it on anything but Motorola systems (no other WACN I've come across gives SNE data, except BEExx).

The TIA spec does list the other MFIDs but it's kind of roundabout to get to them. TIA-102-AABC-C (the main spec for P25 trunking) refers the reader to TIA-102-BAAC-A, which is now TIA-102-BAAC-C. That document, in turn, says "00 and 01 are 'standard P25', see 'MFID Manufacturers Identifier Number Assignment Guide and Procedures (July 2008)' for others". Despite searches on the TIA web site, I can't come up with the July 2008 version, but a January 1999 version is available at http://ftp.tiaonline.org/tr-8/TR-8.15/Public/_Superseded_Versions/mfid0119a.pdf ... and an October 2007 version at http://ftp.tiaonline.org/tr-8/TR-8.15/Public/MFID_Assignments_080723.doc.

 

[GTR8000]

I'm going to "bump" this thread so Jay and everyone else subscribed see cvv's post right above mine. Approved posts from new members don't cause a new post to show up, so they might miss it.

 

[Jay911]

Thanks to both of you for your contributions. I am in an area with sporadic net access, so I haven't been checking the forums every day. But I am getting to do some monitoring of a P25 system that continues to expand and build out so that's all good.

 

[cvv]

New Version is Up!

Just wanted to let you know that the new version that supports both hexadecimal and decimal was posted earlier this week.

Also added a bunch of MFID's that I didn't have for the first version (<= thanks again Jay911).

If you have any other suggestions, please feel free to post them here and I'll monitor this thread,

Best,
Clay

 

[pawsrock]

Help to Understand

Can someone tell me how this helps with scanning?
Thanks
Ron Fone