SDR Trunk 0.6.0 beta1 - incorrect channel numbers?

[Fredo68]

Hi,

I've recently moved from SDR Trunk 0.6.0 alpha7 to the new beta1 version.

I had a busy local Tier III network set up nicely with all 154 (!) channels manually entered and working fine. The beta1 version gives a different channel number from those I know are broadcast - the real numbers are in the 16xx range but beta1 is giving numbers in the 8xx range. So none of my laboriously typed channels work anymore.

I could work out what the channel numbers translate to and alter the playlist but since it previously all worked, it doesn't seem a great idea and less so when I think of 154 alterations.

Alpha 7 still works fine so I can use that but am also stuck being unable to upgrade.

Any idea why it would do this?

 

[BM82557]

I posted this on the SDRTrunk Google Groups

 

[Fredo68]

Thanks for posting this over in the Google group. I see at least a couple of other people have the same issue.

 

[chrismol1]

Yea I noticed this on DMR I don't often go to recently, same problem, what the heck haha, it is not just you. Kind of funny how that could have happened. whoops

 

[dave3825]

SDR Trunk 0.6.0 Beta 2

WARNING: Breaking Changes. This version changes the DMR decoder channel configuration's channel to frequency mapping format. Previously, the user specified each Logical Slot Number (LSN) and the corresponding frequency and this required duplicate entries, one for each timeslot. This has been updated to use the Logical Channel Number (LCN) and you only have to input one map entry for each repeater LCN. The LCN and Frequency values can be found in the Radio Reference details for the DMR system.

If you wish to continue using versions prior to 0.6.0 Beta 2, please make a backup copy of your playlist before you modify your current playlist to change the DMR channel to frequency maps. That way you can switch between playlists.

 

[Fredo68]

SDR Trunk 0.6.0 Beta 2

I saw that on the Github but thanks for posting it here. I can't think of a way to translate the LSNs to LCNs. I did try to monitor the same channel in DSD+ and DSD-FME as the latter also uses LCNs. There didn't appear to be any logic to the LCNs. If LSN 1605 = LCN842 then why does 1667=833?

And no the LCNs can't be found here so not sure why they say that so confidently.

Transport for London Buses Trunking System, London, England

Transport for London Buses Trunking System Profile

www.radioreference.com

 

[GTR8000]

The channel numbers for that system are all incorrect. Looks like someone put slot #'s instead of the actual channel numbers years ago. Needs a lot of TLC, perhaps you can figure out what the correct LCN or LSN (CH ID) are, and submit them so it can be cleaned up.

 

[Fredo68]

The LSNs are broadcast on the network and advance two slots for every 12.5kHz channel - eg 1607 is 25kHz higher than 1603. It was easy if labourious to work them out. Looking at the LCNs that SDRtrunk and DSD-FME throw up there's no numerical sequence - eg 833 is many kHz LOWER than 820.

I agree the RR entry I linked to is a mess but I'm not seeing any LSNs (in the 1605 to 1757 range) or any LCNs - correct or not. Problem is, it may not be legal to post anything about UK RF networks

ETA the London bus network was previously MPT1327 and I think some remnants of that remain on the page

 

[GTR8000]

The LCN value should be approximately half of the LSN/CH ID. There is a formula for it, because it's not exactly half.

1667/2 = 833.5, which is rounded down to 833

In other words, LCN 833/LSN 1667 = time slot 0 and LCN 833/LSN 1668 = time slot 1

DMR LSNs For Tier-III Systems

There seems to be an inconsistency between the way that DMR Tier III and DMR Cap/Con+ site frequencies are represented in the database. For example, this Con+ system: Syracuse Site Details (SaiaNet) has a site frequency table with LCN, LSN, Frequency and Color Code. But, this Tier-III system...

forums.radioreference.com

LCN to Frequency calculator for DMR TIII

Seems like a few people are interested in this calculator I mentioned in a post a few days ago. Here it is. This is only for calculating LCNs for DMR TIII. It will not work for CAP+,CAP MAX, CON+ or any other system. This 'DMR_TIII_LCN_Freq_calc' is provided 'as is'. - This is just a basic...

forums.radioreference.com

 

[lwvmobile]

In case anybody is wondering why some software/scanners/radios use one format, and why others use the other, I couldn't tell anybody, but I can tell you what the manual for DMR TIII says, and tell you how people figure out the LCN or LSN value (or in terms of the manual, Logical Physical Channel Number, and Logical Channel Number)

DSD-FME, for example, uses only the LPCN (RF 'channel') for tuning but others use the LPCN + LCN (RF Channel + Time Slot) in an appended fashion, but will display both for user convenience. So, only using the LPCN (12-bit value) for a call, you get values, for example, just tossing random values out there. TG on 12-bit LPCN (RF Payload Channel) 123, LCN (TS TDMA Channe) 0. By shifting the value 123 to the left one (multiply by 2) and appending the timeslot value, this will become 246. If it were LPCN (RF) 123, LCN (TSl) 1, then it would be 247. To further complicate things, in order to prevent a 'channel 0 LSN 0' bias (which should be invalid anyways) some software will further add an additional 1 to that 13-bit value, so instead of 246 and 247, its 247 and 248 if enumerated as TS1 and TS2 and not as TS 0 and TS1.



So, in short, some people only use the LPCN (12-bit value), others use the LPCN + LCN bit appended (13-bit value). It doesn't help that the official ETSI manuals use different terminology than what most people use to mean the LCN and LSN, respectively.

SDRTrunk just switched from one to the other, so that's why your channels aren't lining up anymore.

 

[Fredo68]

The LCN value should be approximately half of the LSN/CH ID. There is a formula for it, because it's not exactly half.

1667/2 = 833.5, which is rounded down to 833

In other words, LCN 833/LSN 1667 = time slot 0 and LCN 833/LSN 1668 = time slot 1

DMR LSNs For Tier-III Systems

There seems to be an inconsistency between the way that DMR Tier III and DMR Cap/Con+ site frequencies are represented in the database. For example, this Con+ system: Syracuse Site Details (SaiaNet) has a site frequency table with LCN, LSN, Frequency and Color Code. But, this Tier-III system...

forums.radioreference.com

LCN to Frequency calculator for DMR TIII

Seems like a few people are interested in this calculator I mentioned in a post a few days ago. Here it is. This is only for calculating LCNs for DMR TIII. It will not work for CAP+,CAP MAX, CON+ or any other system. This 'DMR_TIII_LCN_Freq_calc' is provided 'as is'. - This is just a basic...

forums.radioreference.com

That calculator was very useful so many thanks for the tip. I retyped 152 LCNs and it works! Whatever I was trying to with DSD-FME clearly was way off course.

How do I submit my data for inclusion in the database?

 

[BM82557]

That calculator was very useful so many thanks for the tip. I retyped 152 LCNs and it works! Whatever I was trying to with DSD-FME clearly was way off course.

How do I submit my data for inclusion in the database?

In the database page for the system click on the Menu icon at the top right of the page, scroll down and click on Submit Changes --