Understanding NexEdge Trunking

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EricCottrell

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Hello,

One thing I noticed is:
"Site 4 - 452.7375 (control channel; RAN=4); voice channel 451.45 (RAN=9)"

On NexEdge Trunked systems, all voice channels have the same RAN value as the control channel. The field used for the RAN on a conventional system is the Site Id modulus 64 for a trunked system. A RAN of zero does not mean monitor all RAN values, but rather the RAN for Sites 64, 128, etc.

451.000 would be a voice channel for site 9, 73, etc.

Talkgroups could likely be on multiple sites, so there can be some confusion when receiving multiple sites.

73 Eric
 

rbrtklamp2

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alot of what is on the radio reference data base is wrong for this system is wrong. I went and pulled every license for the owner of the system off of the FCC website and had a lot of luck finding channels. Unfortunetly not all of them, well at least not yet. I have ordered some better SDR dongles and new usb hub so hopefully sonn I will be able to better decode this system. Now onto the questions, Can a site have more than one base freq? As you can see from the site I posted below its pretty much all over the spectrum so I am thinking this is a random bandplan but I could be wrong. Does anybody see a pattern in the frequencies I am missing? at this point I just want to get the last two freqs for this site out of the way and move onto the next site. Eric if you could help me with this I would greatly appreciate any advice you may have. Here is what i have so far and all frequencies for this site have been confirmed except for the two I am missing.

NEXEDGE48, 14, 6, 21, 452.02500, 0.0, 0
NEXEDGE48, 14, 6, 38, 452.42500, 0.0, 0
NEXEDGE48, 14, 6, 238, 463.48750, 0.0, 0
NEXEDGE48, 14, 6, 275, 463.93750, 0.0, 0
NEXEDGE48, 14, 6, 351, 0.0, 0.0, 0
NEXEDGE48, 14, 6, 424, 471.85000, 0.0, 0
NEXEDGE48, 14, 6, 468, 472.08750, 0.0, 0
NEXEDGE48, 14, 6, 513, 472.31250, 0.0, 0
NEXEDGE48, 14, 6, 537, 472.42500, 0.0, 0
NEXEDGE48, 14, 6, 544, 472.45000, 0.0, 0
NEXEDGE48, 14, 6, 563, 472.55000, 0.0, 0
NEXEDGE48, 14, 6, 593, 472.7125,0.0, 0
NEXEDGE48, 14, 6, 734, 0.0, 0.0, 0
NEXEDGE48, 14, 6, 755, 463.31250, 0.0, 0
NEXEDGE48, 14, 6, 824, 472.00000, 0.0, 0, CC
 

EricCottrell

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alot of what is on the radio reference data base is wrong for this system is wrong. I went and pulled every license for the owner of the system off of the FCC website and had a lot of luck finding channels. Unfortunetly not all of them, well at least not yet. I have ordered some better SDR dongles and new usb hub so hopefully sonn I will be able to better decode this system. Now onto the questions, Can a site have more than one base freq? As you can see from the site I posted below its pretty much all over the spectrum so I am thinking this is a random bandplan but I could be wrong. Does anybody see a pattern in the frequencies I am missing? at this point I just want to get the last two freqs for this site out of the way and move onto the next site. Eric if you could help me with this I would greatly appreciate any advice you may have. Here is what i have so far and all frequencies for this site have been confirmed except for the two I am missing.

NEXEDGE48, 14, 6, 21, 452.02500, 0.0, 0
NEXEDGE48, 14, 6, 38, 452.42500, 0.0, 0
NEXEDGE48, 14, 6, 238, 463.48750, 0.0, 0
NEXEDGE48, 14, 6, 275, 463.93750, 0.0, 0
NEXEDGE48, 14, 6, 351, 0.0, 0.0, 0
NEXEDGE48, 14, 6, 424, 471.85000, 0.0, 0
NEXEDGE48, 14, 6, 468, 472.08750, 0.0, 0
NEXEDGE48, 14, 6, 513, 472.31250, 0.0, 0
NEXEDGE48, 14, 6, 537, 472.42500, 0.0, 0
NEXEDGE48, 14, 6, 544, 472.45000, 0.0, 0
NEXEDGE48, 14, 6, 563, 472.55000, 0.0, 0
NEXEDGE48, 14, 6, 593, 472.7125,0.0, 0
NEXEDGE48, 14, 6, 734, 0.0, 0.0, 0
NEXEDGE48, 14, 6, 755, 463.31250, 0.0, 0
NEXEDGE48, 14, 6, 824, 472.00000, 0.0, 0, CC
Hello,

Unfortunately it appears this system is using a completely customized map with the original system frequencies in ascending order. 351 is likely between 463.9375 and 471.8500. I would guess a 464 or 470 MHz frequency. 734 appears to be a late addition so it could be anywhere.

73 Eric
 

rbrtklamp2

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Thanks Eric I appreciate the quick response. The answer unfortunately is what I was afraid you would say. But you know what they say half of the fun of this hobby is the hunt :lol:. Thank you so much for your help I will be posting some other sites that will hopefully be a little easier to decipher in the near future.

Thanks again,
Bob
 

natedawg1604

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Greetings and Happy new year.

Well, I'm having some difficulty finding a frequency assigned to a small VHF Nexedge9600 Trunked System. So, I've got a few questions:

1. Once you find the Control Channel, does DSD+ 1.101 automatically display the active channel numbers for your system in the event log window (i.e. before you've added any entries to the frequency file)? I'm assuming it does, I just want to be absolutely certain.

2. Do Nexedge 9600 systems typically use 1 channel per frequency (i.e. as opposed to DMR)?

As noted above, I've found a small VHF NXDN 9600 system; in DSD+ the CC shows Channels 1,2 and 3. So far I've found two frequencies (152 Mhz area, from a block of paging freqs in ULS), one is the control channel and a second is a voice channel, Channel 2. When running DSD+ 1.101 in trunked mode with FMP and so forth, I can hear voice grants from channel 2, and the CC window shows voice grants for Channel 3. But, I'm beating my head against the wall finding the third frequency, for Channel 3.

The 2 frequencies I found so far have a very strong signal; I initially found them with my hardware scanner randomly searching through 150-162 Mhz (I highly suspect the system is operating in 150-155 Mhz, so I also run a separate custom search in this narrower range).

In any event, it seems like I should fairly easily find that third frequency by searching the VHF band with my hardware scanner, while Channel 3 is active in DSD+.

The system in question is not terribly active, but it should be active enough to find the remaining voice channel without this much difficulty.

Any ideas on what I might be missing here?
 
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natedawg1604

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Greetings and Happy new year.

Well, I'm having some difficulty finding a frequency assigned to a small VHF Nexedge9600 Trunked System. So, I've got a few questions:

1. Once you find the Control Channel, does DSD+ 1.101 automatically display the active channel numbers for your system in the event log window (i.e. before you've added any entries to the frequency file)? I'm assuming it does, I just want to be absolutely certain.

2. Do Nexedge 9600 systems typically use 1 channel per frequency (i.e. as opposed to DMR)?

As noted above, I've found a small VHF NXDN 9600 system; in DSD+ the CC shows Channels 1,2 and 3. So far I've found two frequencies (152 Mhz area, from a block of paging freqs in ULS), one is the control channel and a second is a voice channel, Channel 2. When running DSD+ 1.101 in trunked mode with FMP and so forth, I can hear voice grants from channel 2, and the CC window shows voice grants for Channel 3. But, I'm beating my head against the wall finding the third frequency, for Channel 3.

The 2 frequencies I found so far have a very strong signal; I initially found them with my hardware scanner randomly searching through 150-162 Mhz (I highly suspect the system is operating in 150-155 Mhz, so I also run a separate custom search in this narrower range).

In any event, it seems like I should fairly easily find that third frequency by searching the VHF band with my hardware scanner, while Channel 3 is active in DSD+.

The system in question is not terribly active, but it should be active enough to find the remaining voice channel without this much difficulty.

Any ideas on what I might be missing here?
Cancel that last post. I finally found the missing frequency, it was 7.5 kHz away from another VERY strong data or paging channel on another system, AND 7.5 Khz away in the other direction from yet another DMR frequency (my hardware scanner wasn't sensitive enough to find it, but I finally caught it with SDR#; not many systems in my area operate on directly adjacent channels, so I figured my hardware scanner would find it).

Although the frequency decodes fine with SDR#, I'm having trouble getting FMP to recognize it in trunked mode (for some reason in manual mode it works, not sure why exactly) Hopefully I can mess with the step size, bandpass filter and/or other settings in FMP and somehow get it working.
 

LimaZulu

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Ok, I need some help because I'm completely lost. I have multisite NXDN48 network here. It has 5 sites. I can see all of them except site 3 which seems to be inactive or it's just way too far from me or maybe very weak signal. All sites has 5 channels including one control channel - so 1 control channel and 4 voice channels. Site 1,2 and 4 are mostly active during day time and not so active during the night. Site 5 by now is pretty quiet and "lonely" :) At first I was monitoring site 1 and found all frequencies. At day one I had voice on channels 1, 2, 4 and 5. Channel 3 was control channel. The next day I had voice on channel 1,2,3 and 5. Channel 4 was control channel. By now all seems to be ok. We have control channel rolling - that's ok except that channel 4 was on a different frequency from the one I found yesterday. And then there was.....something strange. I saw that there is activity on some channels but there was no audio. I saw that the receiver is jumping right on the frequency that I did found on day one but there was nothing. Did some manual tuning here and there and found the frequency. It started to be more and more odd on the next day when the story repeated itself - again there was different frequency for the controll channel and different frequencies for some other channels, but not all of them. All in all, channel 1 over site 1 is the one that never changed it's frequency Since then i have one question that bothers me - how many frequencies can be attached to a channel and is this possible at all? I mean how can channel 3 for example, to be on one frequency, the next day the frequency is different and so on, and so on.... Then I realized something. Site 1, 2 and 4 seems to cover each one. I mean, whenever there is activity on site 1, channel 4 for example, you can hear exactly the same on site 4 channel 18. At first I tought that I accidentally clicked over some channel from other site and that's why I have so many different frequencies for one channel. By now I had no time to monitor other site's freciencies but the one I have didn't match so there is a little chance for that to be true.
I know that this explanation is pretty messy but that's becuase the mess in my head as I'm trying to figure the things out :) So, please help me by pointing me in some direction or maybe exact explanation (if there is at all) :) If you need some other explanation please ask and I'll try to explain more clearly. Thanks in advance!
 

DSDPlus

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Site 1, 2 and 4 seems to cover each one. I mean, whenever there is activity on site 1, channel 4 for example, you can hear exactly the same on site 4 channel 18.
This is normal. It is why the system has 5 sites. So the same activity can be received at multiple sites.


At first I tought that I accidentally clicked over some channel from other site and that's why I have so many different frequencies for one channel. By now I had no time to monitor other site's freciencies but the one I have didn't match so there is a little chance for that to be true.
I am thinking that you assumed that some voice channels you found belonged to the control channel you were monitoring. So while monitoring site 1's control channel, you found a site 2 or 3 or 4 voice channel, but marked it as belonging to site 1. You need to look at the RAN values on the voice channels, They will match the site number.
 

ve3tuk

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I am looking at a single channel NXDN site on a multi site network.* It behaves as a control channel, but voice traffic is carried on the same channel.* DSDPlus recognizes this as a control channel with neighbors, it reports radio registrations (TG and RID), and it synthesizes voice traffic but does not show any talk group call information in the log. Something a bit different..


Sent from my XT1032 using Tapatalk
 

EricCottrell

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I am looking at a single channel NXDN site on a multi site network.* It behaves as a control channel, but voice traffic is carried on the same channel.* DSDPlus recognizes this as a control channel with neighbors, it reports radio registrations (TG and RID), and it synthesizes voice traffic but does not show any talk group call information in the log. Something a bit different..


Sent from my XT1032 using Tapatalk
Hello,

DSDPlus may have problems handling this since it is not very common. If you can create a DSDPlus raw audio file of some voice traffic, with control channel in between, that would help the DSDPlus developers. Upload the file to your favorite file sharing site and post the link.

73 Eric
 

garys

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If you know all of the frequencies for a particular system, what is the process for figuring out the frequency map. I'm assuming that in this case the RR DB is correct, but there is no other information.

I won't be able to try to figure this system out until the fall, but it would be interesting to work on when I'm able.
 
D

DaveNF2G

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I have a multisite IDAS system in my area (a derivative of NXDN) and it acts more like LTR, having data blips on system channels instead of a constant CC.
 

microx

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Kenwood calls their version of NX trunking (which has the constant Control Channel) Type C.
Icom calls their version of NX trunking (which has no control channel like LTR) Type D.

Since you state IDAS, that indicates it is an Icom system, which should be the Type-D

On some Kenwood radios, (NX-x20 series) you can install different firmware to permit Type-D trunking, but you will lose the Type-C functionality. I may be wrong, but I don't believe they have a model & firmware that will do both versions simultaneously.

I'm not familiar with Icom IDAS models to be able to comment on them.
 

DaveH

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I am looking at a single channel NXDN site on a multi site network.* It behaves as a control channel, but voice traffic is carried on the same channel.* DSDPlus recognizes this as a control channel with neighbors, it reports radio registrations (TG and RID), and it synthesizes voice traffic but does not show any talk group call information in the log. Something a bit different..


Sent from my XT1032 using Tapatalk
I think you are referring to the MRC de Papineau system in Quebec, on 152.300/.435/.555/.9975 etc. I have not seen more than one channel per site. You can tell when it switches from control to voice just by the sound. Once I caught a bit of voice on one site; not sure when their peak usage time is when combined activity is most likely captured.

Dave
 

slicerwizard

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Could also be OnQue. The network has a number of single channel / composite control channel sites. Recent versions of DSD+ are handling the CCC sites properly and synthesizing the voice calls and logging their group and radio IDs.
 

garys

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Is there a formula for calculating channel numbers if you have the frequencies? The DB lists frequencies for the Daphne, AL NXDN trunk, but no channel numbers or other information. I'll be down there soon and hopefully will have some time to try to sort this out.

Thanks.
 
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