SDS100/SDS200: LCN Finder SDS1000 Limited to 5 LCN?

[Hit_Factor]

I have a low powered NEX4 network that I've been scanning for several weeks now with my Icom IC-r30 and then I added the SDS-100 about 2 weeks ago. I work at this site and have been a user on this network for quite a few years. It's a rural setting and I rarely see any NXDN activity that does not belong to this network. I have access to list of talkgroups and radio IDs, so it's easy to spot out of network activity.

Using license data I started with about 70 frequencies. I'm down to about 26 now that have appropriate talkgroup and radio IDs. The R30 provides a very useful RxLog with this information. However, it doesn't know anything about LCNs. RAN is usually a 1 and sometimes a 2.

When I run analyze/status it gives me a System ID/Site Id/Freqs/RAN. I never get more than 5 freqs, but it doesn't really matter - none of this info is used in a FL for a NXDN trunk system. I have run LCN finder for 6-8 hours without finding more than 5.

When I run LCN finder on the 26 freqs, it stops at 5 LCNs found. The scanner finds them before I can finish a cup of coffee. It's pretty busy.

So I trimmed out the 5 freqs with LCNs and ran the finder again. Again, just 5 LCNs are found on the 22 freqs now in the list. Funny thing is I didn't expect to see an LCN of 7 on more than one freq. This happens with a couple of other freq/LCN combos only. I expected each LCN to be unique to the freq, I don't know why I expected that but I did. Is this normal? Can two freqs have the same LCN?

Trimming out another 4 freqs, because I think LCN 1 is the control freq, I run LCN finder again. It takes a little longer this time, but it eventually gets to 5 found LCNs.

To wrap this up I now have a site with 12 freqs in it. At some point each freq was identified to have a LCN. When I run LCN finder on this set of 12 freqs, it stops at 5. When I say stops, it appears as though it is still searching, it just never produces any more results. The LCNs found are 1, 4, 5 ,6 ,7. I think 1 goes with the control freq, as that freq seems to be active all of the time. I have never seen a LCN of 2 found for this system.

Should the LCN finder find more than 5 at a time?

Is there another technique to snooping out this system? I have a HP-2 and several amature radio HTs, but I'm not sure those will help with NXDN.

 

[jonwienke]

LCN Finder should find all frequencies for the site, whether 2 or 25.

The site with 12 frequencies, are they all showing the same system and site IDs?

 

[mtindor]

Please provide an RRDB link to the low powered trunk system you are monitoring.

Mike

 

[Hit_Factor]

LCN Finder should find all frequencies for the site, whether 2 or 25.

The site with 12 frequencies, are they all showing the same system and site IDs?

Yes, remember it stopped at 5.

 

[Hit_Factor]

Please provide an RRDB link to the low powered trunk system you are monitoring.

Mike

It's not in RR. That's one reason why I started with license information.

 

[mtindor]

It's not in RR. That's one reason why I started with license information.

Would you provide some license information? Ya know, an indication of what company's licenses you are scanning for active frequencies? How about data -- actual verified RANs / channel numbers / anything you got.

I realize you might not want to share it because you are enjoying discovering the system and then perhaps planning to submit it to RR. But it's pretty difficult for anyone else to give you suggestions without knowing more.

It's very common for businesses with multiple licenses to not use all frequencies on a given licenses, or to use a few off of each one.

They might be using some frequencies as conventional frequencies (for which there would be different RANs and there would be no channel numbers or sys/site IDs).

Timken in Canton Ohio has 3 locations, four NXDN trunked sites in those locations, and a huge slew of conventional NXDN in use. In some cases trunked license frequencies are used on conventional NXDN repeaters.

For NXDN trunked systems with control channels, all frequencies for a particular site are going to share the same RAN, and the RAN will be the same as the site number (unless they have more than 63/64 sites). So if the site ID is Site 1 or 2, and if there is a dedicated control channel, the only frequencies that will apply to that particular site are those frequencies which show a RAN of 1 or 2.

It should not be surprising at all that the LCN finder stopped at 5. It could be a flaw in the LCN Finder for sure. But it could be simply the case where the site actually only has 5 active frequencies.

Also keep in mind that LCN Finder ONLY works if the channels are active when you are running LCN Finder. If the system is set up to only use certain frequencies if the loading becomes greater, you may never see activity on those other freqencies and thus may never get an LCN out of them. You will want to determine the busiest time of day/week on the system and then use LCN Finder at that time to monitor the frequencies.

I wish I could provide more ideas for you, but you simply aren't including enough information to go on.

Mike

 

[Hit_Factor]

Would you provide some license information? Ya know, an indication of what company's licenses you are scanning for active frequencies? How about data -- actual verified RANs / channel numbers / anything you got.
Mike

This kind of data Mike? The only time I see RAN 2 is communication between radios 2000 and 2001

Frequency Mode Caller Called Call Type D.SQL Code Received date
464.1625 NXDN-VN 2001 1001 GRP 2 6/21/2018 05:40
462.0125 NXDN-VN 924 1001 GRP 1 6/21/2018 05:42
464.1625 NXDN-VN 2000 1001 GRP 2 6/21/2018 05:49
463.6125 NXDN-VN 917 1001 GRP 1 6/21/2018 05:50
463.6125 NXDN-VN 2000 1001 GRP 1 6/21/2018 05:50
463.6125 NXDN-VN 2000 1001 GRP 1 6/21/2018 05:54
463.83125 NXDN-VN 921 1001 GRP 1 6/21/2018 05:59
453 NXDN-VN 2000 1001 GRP 2 6/21/2018 06:00
463.31875 NXDN-VN 2000 1001 GRP 1 6/21/2018 06:00
463.6125 NXDN-VN 827 1001 GRP 1 6/21/2018 06:00
463.6125 NXDN-VN 837 1001 GRP 1 6/21/2018 06:01
463.83125 NXDN-VN 2000 1001 GRP 1 6/21/2018 06:01
463.83125 NXDN-VN 2000 1001 GRP 1 6/21/2018 06:01
463.83125 NXDN-VN 2000 1001 GRP 1 6/21/2018 06:02
463.61875 NXDN-VN 2000 1001 GRP 1 6/21/2018 06:03

I have 10s of thousands of lines of the above data.

These are absolutely used freqs in the system with the results of the last LCN session, I left them in search mode for RAN. Each of these freqs were identified by LCN finder for this system.
451.918700 1 Search
452.875000 0 Search
462.012500 4 Search
463.318700 5 Search
463.612500 6 Search
463.831200 7 Search
468.318700 0 Search
468.831200 0 Search
452.475000 0 Search
453.000000 0 Search
463.300000 0 Search
463.906200 0 Search

These are verified by the R30. I took 60-80 hours of data and consolidated the freqs to those that used proper TG and radio IDs. Very high probability.
451.906200 0 Search
451.918700 1 Search
452.300000 0 Search
452.331200 0 Search
452.475000 0 Search
452.875000 3 Search
453.000000 0 Search
462.012500 4 Search
462.068700 0 Search
462.275000 0 Search
463.300000 0 Search
463.318700 5 Search
463.456200 0 Search
463.612500 6 Search
463.693700 0 Search
463.762500 0 Search
463.831200 7 Search
463.906200 0 Search
464.162500 0 Search
466.406200 0 Search
467.012500 0 Search
468.300000 0 Search
468.318700 0 Search
468.612500 0 Search
468.831200 0 Search
469.162500 0 Search

It's very common for businesses with multiple licenses to not use all frequencies on a given licenses, or to use a few off of each one.

They might be using some frequencies as conventional frequencies (for which there would be different RANs and there would be no channel numbers or sys/site IDs).

This company is definitely using conventional radios in the same 450-470 range. I mentioned in my original post that I'm using the R30 for data. The R30 gives me the mode, thats the first data snippet in this message. That's how I got down to 26 freqs. I work at this site - I know that there isn't any non-trunked NXDN in use.

It should not be surprising at all that the LCN finder stopped at 5. It could be a flaw in the LCN Finder for sure. But it could be simply the case where the site actually only has 5 active frequencies.

LCN Finder stopped at 5 even when 12 freqs in this system were isolated into 1 site and scanned. Each of the 12 were previously identified by LCN Finder. I think there might be a problem with LCN Finder.

Do you have any thoughts on LCN finder claiming two different freqs have the same LCN of 7?

Also keep in mind that LCN Finder ONLY works if the channels are active when you are running LCN Finder. If the system is set up to only use certain frequencies if the loading becomes greater, you may never see activity on those other freqencies and thus may never get an LCN out of them. You will want to determine the busiest time of day/week on the system and then use LCN Finder at that time to monitor the frequencies.

I think I covered this, the short list of 12 freqs only takes minutes for LCN finder to claim a LCN for each of these. It is a very busy site, 20ish talkgroups and several hundred radios.

I wish I could provide more ideas for you, but you simply aren't including enough information to go on.

I'm trying Mike

 

[scan-pa]

What is the fcc license for this system?

Sent from my SM-G935V using Tapatalk

 

[scan-pa]

The only trunked system that matches to most of the freqs you have provided on here is WQQF221 and WQQD296 with the site located in Berrien County Mi....

https://www.radioreference.com/apps/db/?fccCallsign=WQQF221

and

https://www.radioreference.com/apps/db/?fccCallsign=WQQD296

Are these it?

If it is the site, it looks like there is only 7 Rptr. pairs in use for the first Licence and 9 Rptrs for the 2nd. one.