LTR-Analyzer 3.0

[asurnin]

I have gone back to read some LTR threads on here. I found that my UT setup seems to act a bit differently.

I have found an LTR channel that has a constant data stream- and the first time I parked on that channel in tune mode (PRO-106 scanner, btw) and the new system window popped up. The control channel populated with the frequency. It also populated 8 different other LCN slots with 0.000 frequencies. I monitored this system late at night, when it was unlikely to be active. Will the other 8 slots get populated if the system is active? I don't know a whole lot about LTR, but I understand having a dedicated control channel is uncommon.

I found the frequencies off FCC license database, and have not attempted to put them all into order yet. I guess that would be a question for a different forum.

[DSheirer]

Originally Posted by asurnin

I have found an LTR channel that has a constant data stream- and the first time I parked on that channel in tune mode (PRO-106 scanner, btw) and the new system window popped up. The control channel populated with the frequency. It also populated 8 different other LCN slots with 0.000 frequencies. I monitored this system late at night, when it was unlikely to be active. Will the other 8 slots get populated if the system is active? I don't know a whole lot about LTR, but I understand having a dedicated control channel is uncommon.

LTR-Net systems have a Home Status Channel that transmits continuously, but I've never tried UT against any of the systems here in NY to see how it responds.

If it is LTR-Net, LTR-Analyzer v3.0 will decode and tell you all of the LCN frequencies and site info.

[asurnin]

I'll look into the analyzer, thanks guys.

[n4yek]

Originally Posted by DSheirer

LTR-Net systems have a Home Status Channel that transmits continuously, but I've never tried UT against any of the systems here in NY to see how it responds.

If it is LTR-Net, LTR-Analyzer v3.0 will decode and tell you all of the LCN frequencies and site info.

Where do you find LTR Analyzer v3.0? I can only find v1.7.
Thanks

[inigo88]

Wait a minute...

Every conventional LTR standard system has a "home channel", it's the HH LCN in each talkgroup 'A-HH-GGG.' (Where A is the Area bit 0 or 1, HH is the home repeater or home Ch LCN, and GGG is the talkgroup.)

Also as far as I can tell LTR-Net is just an enhanced version of LTR Standard which uses higher LCN numbers than 20 for enhanced signalling features, while remaining backwards compatible with regular LTR radios on the system.

LTR-Multinet is the APCO-16 compliant version that was marketed to public safety users, and to my knowledge the only LTR variant that used a control channel. (I think you guys are confusing -Net and -MultiNet, but correct me if I'm mistaken.)

PassPort doesn't even have LTR in the name, the only thing they have in common with each other is subaudible data bursts. PassPort is totally it's own type of system with radio IDs, I-calls, emergency button functionality, registration/deregistration and multi-site roaming. PassPort is easily distinguishable by the faster idle bursts (every 2 sec), although in practice I usually only see that on the registration channel, with the rest of the voice channels getting the traditional once every 10 sec burst.

Here's the wiki on LTR, for reference: Logic Trunked Radio - The RadioReference Wiki

[inigo88]

Originally Posted by n4yek

Where do you find LTR Analyzer v3.0? I can only find v1.7.
Thanks

I second this. I'd love to play around with it, although I have yet to run across an LTR-Net or LTR-Multinet system on the west coast. We just have a ton of PassPort, MotoTRBO and NEXEDGE/iDAS these days.

[Saint]

Originally Posted by n4yek

Where do you find LTR Analyzer v3.0? I can only find v1.7.
Thanks

Stop looking for V3.0, you have the right one already.
Steve

[Michael-SATX]

Thanks Steve, thats GREat, I'll keep on using v1.7, love it !

Also, high on my list of LTR tools is LTRDUMP.EXE for raw LTR data to examine for many reasons.
I see LTRDUMP report LTR Multi-Net Burst, LTR Passport Burst and LTR Regular here in SATX.

ps ~ In looking to polish up my understanding of LTR Systems: Here goes ...

Q: Is LTR Net and LTR Multi-Net different animals and if so ... how so ... ?

ie ~ Here in SATX, we have a ton of Passport and LTR systems from several vendors to keep busy with.
Q: Is a system a LTR system with multiple sites and TG's that Affiliate and appear accross each site
and they are under 20 LCN's and 400 Mhz ... so what are these systems called ?

[inigo88]

Originally Posted by Michael-SATX

Q: Is LTR Net and LTR Multi-Net different animals and if so ... how so ... ?

Michael, try reading my post #7 in this thread for starters.

Originally Posted by saint

Stop looking for V3.0, you have the right one already.
Steve

Why do you say that? DSheirer just referred to it by name earlier in the thread. There's also reference to it in the comments of this LTR-Net system: Mobiletech Communications Trunking System, Various, New York - Scanner Frequencies

Are you guys hoarding a secret version?

Also, I see now that I was apparently mistaken regarding the home-status channel on LTR-Net systems (sorry DSheirer!). Does anyone have a sound sample of one, or know what they sound like? Is it an actual control channel or just an open carrier sound made up of LTR subaudible data? I haven't run across any LTR-Net (that I know of) here in California and I'm really curious now.

[Saint]

Originally Posted by inigo88

Michael, try reading my post #7 in this thread for starters.



Why do you say that? DSheirer just referred to it by name earlier in the thread. There's also reference to it in the comments of this LTR-Net system: Mobiletech Communications Trunking System, Various, New York - Scanner Frequencies

Are you guys hoarding a secret version?

Can anyone point me to the version V3.0 that can be downloaded ?????
Steve

[Unitrunker]

This is all news to me. I use LTR-Analyzer to ID local systems. I thought it was strictly LTR. Was Passport added at some point?

I'll sit back and wait for Andrew to reply.

[Michael-SATX]

Before Andrew replies, I'll just say that I only use LTR-Analyzer strickly for LTR Regular systems.
For Passport decoding, I use both LTRDUMP and LTRTRUNK programs with my serial DSR Slicer.
Speaking of DataSlicers.com , my pass through Data slicer sure acts squirrely especially
with EDACS systems and trunker ... lots of "?" and spinning decoder indicator wheel jittering, etc. ?
It's tollerable with LTR systems but not with EDACS systems. I swapped dataslicers with a friends
setup and it moved the problem ... my decoding was smooth and clean and his had problems then.
I have different laptops and a handfull of tapped scanners and have narrowed down my woes to
my new dataslicer ... I'm wondering if I just got a bad build and a replacement from Dataslicers.com
would solve my decode problems ? I'm currious as to why he doesn't mention LTR on his website,
He just indicates they are for EDACS and Motorola systems. My inquiry email went un-answered
so I just took a chance and ordered one anyway crossing my fingers that it would do LTR systems ?
Bottom line, who's slicers are known to work well ? I'd be curious to ask you all who's slicers u have ?
I have his 2-level serial pass-through "Super Data Slicer" model ... anybody else use this one also ?
Mine is in a gray plastic DB9 hood and my friends pass through slicer that works great is black in one.
Do you think I should try to see if dataslicers.com would warranty swap with mine to get a good one ?

[DaveNF2G]

According to an email I received a few weeks ago, LTR Analyzer v3 only works for LTR-Regular systems.

PassPort is an LTR offshoot, regardless of what it is called, and often coexists with LTR-Regular on the same repeaters.

[DSheirer]

LTR-Net sites look just like a normal LTR-Standard site, except one of the LCNs is a Home Status Channel (HSC) that is transmitting 24/7. LTR-Net allows mobiles to roam from site to site and voice calls connect across multiple sites. Most scanners will monitor an LTR-Net site, just like normal LTR-Standard, except you'll keep getting a hit on TGID x-xx-253 every time someone turns on their radio and gets assigned a unique-id.

When idle, the HSC transmits LTR-Standard IDLE (255) messages, interleaved with a repeating set of LTR-Net configuration messages. This allows radios roaming onto the site to self-configure. The other LCN's transmit the same message set, but you have to monitor dozens of LTR idle bursts to catch the full message set.

The LTR-Net messages include: site id, neighbor site id's, LCN channel map, LCN transmit frequencies, LCN receive frequencies, and radio unique id assignment/address message.

Here's a snippet of v3.0 running against the MobileTech Fulton site's HSC (LCN 7):

5/06/2012 10:32:21 + OSW: 0 28 00 085 00 32 ACTIVE LCNS LO: 1 3 5 7
5/06/2012 10:32:24 + OSW: 1 07 07 255 05 31 BUSY FREE=5 LCN=7
5/06/2012 10:32:24 + OSW: 0 26 08 161 27 57 NEIGHBOR=59 SEQ=4 RANK=5
5/06/2012 10:32:25 + OSW: 1 07 07 255 01 3C BUSY FREE=1 LCN=7
5/06/2012 10:32:25 + OSW: 0 26 10 193 16 43 NEIGHBOR=48 SEQ=5 RANK=6
5/06/2012 10:32:25 + OSW: 1 07 07 255 07 36 IDLE LCN=7
5/06/2012 10:32:25 + OSW: 0 26 10 193 16 43 NEIGHBOR=48 SEQ=5 RANK=6
5/06/2012 10:32:25 + OSW: 1 07 07 255 03 3B BUSY FREE=3 LCN=7
5/06/2012 10:32:25 + OSW: 1 07 07 255 01 3C BUSY FREE=1 LCN=7
5/06/2012 10:32:25 + OSW: 0 18 24 000 25 49 CURRENT SITE=25
5/06/2012 10:32:26 + OSW: 1 07 07 255 05 31 BUSY FREE=5 LCN=7
5/06/2012 10:32:26 + OSW: 0 24 01 048 04 7B TX FREQ LCN=1 OFFSET LOW=1540
5/06/2012 10:32:26 + OSW: 1 07 07 255 03 3B BUSY FREE=3 LCN=7
5/06/2012 10:32:26 + OSW: 0 24 01 048 04 7B TX FREQ LCN=1 OFFSET LOW=1540
5/06/2012 10:32:26 + OSW: 0 24 01 133 16 1A TX FREQ LCN=1 BAND=VHFHI HIGH=0 FREQ=151.925
5/06/2012 10:32:26 + OSW: 1 07 07 255 05 31 BUSY FREE=5 LCN=7
5/06/2012 10:32:27 + OSW: 0 24 01 133 16 1A TX FREQ LCN=1 BAND=VHFHI HIGH=0 FREQ=151.925
5/06/2012 10:32:27 + OSW: 0 25 01 118 06 45 RX FREQ LCN=1 OFFSET LOW=3782
5/06/2012 10:32:27 + OSW: 1 07 07 255 07 36 IDLE LCN=7
5/06/2012 10:32:27 + OSW: 0 25 01 128 01 50 RX FREQ LCN=1 BAND=VHFHI HIGH=1 FREQ=159.8475
5/06/2012 10:32:27 + OSW: 1 07 07 255 01 3C BUSY FREE=1 LCN=7
5/06/2012 10:32:28 + OSW: 1 07 07 255 03 3B BUSY FREE=3 LCN=7
5/06/2012 10:32:28 + OSW: 0 25 01 128 01 50 RX FREQ LCN=1 BAND=VHFHI HIGH=1 FREQ=159.8475
5/06/2012 10:32:28 + OSW: 0 24 03 089 18 7E TX FREQ LCN=3 OFFSET LOW=2866
5/06/2012 10:32:29 + OSW: 0 24 03 089 18 7E TX FREQ LCN=3 OFFSET LOW=2866
5/06/2012 10:32:29 + OSW: 0 24 03 133 16 27 TX FREQ LCN=3 BAND=VHFHI HIGH=0 FREQ=153.5825
5/06/2012 10:32:29 + OSW: 1 07 07 255 03 3B BUSY FREE=3 LCN=7
5/06/2012 10:32:29 + OSW: 1 07 07 255 01 3C BUSY FREE=1 LCN=7

SlicerWizard modified LTR-Analyzer and released v3.0 to correctly parse the LTR-Net messages, but it's hard-coded with the VHF base frequency 150.0MHz, because that was the only example I had at the time. When I ran it against the Loudoun County, VA school system over the holidays, their system is using a base frequency of 430.0 MHz. You can still figure out the frequency by subtracting 150.0 from the LTR-Analyzer output, and adding it back to 430.0. I haven't seen any 800 MHz systems yet.

LTR-Analyzer v1.7 will decode the LTR-Net message bits/hex, but it will show the LTR-Net messages as Invalid/Unknown.

SlicerWizard said that we can share v3.0 ... PM me with an email address and I'll send a copy.

Denny

[DSheirer]

Originally Posted by Michael-SATX

Q: Is LTR Net and LTR Multi-Net different animals and if so ... how so ... ?

Both systems look identical when you're looking at them on an SDR spectral display. Both have one of their LCN's transmitting 24/7, and the remaining traffic channels transmitting idle bursts every few seconds. The periodicity of the idle bursts is also close ... around 10 seconds a burst. Both use 300-baud sub-audible FSK signalling ( LTR-Net = yes, LTR-Multinet =I think ). LTR-Net uses the same message sync pattern, message size, and CRC checksum as LTR-Standard. LTR-Multinet doesn't.

They shut down our Oswego County 800 MHz LTR-Multinet system a few months ago when they switched to P25, so I didn't get a chance to explore that system.

Originally Posted by Michael-SATX

Q: Is a system a LTR system with multiple sites and TG's that Affiliate and appear accross each site and they are under 20 LCN's and 400 Mhz ... so what are these systems called ?

What you just described matches LTR-Net, and I think it also describes LTR-Multinet. But, I'm not sure if multinet is restricted to only 20 LCNs.

A quick test is to tune your trunking scanner (or LTR-Analyzer) to one of the channels. If the scanner decodes TGIDs during a call, then it may be LTR-Net, since LTR-Net signalling is compatible with LTR-Standard. If you don't see the TGID's decode, then it may be LTR-MultiNet. This also assumes that you know how to id Passport, and don't confuse Passport as one of these systems.

Denny

[DSheirer]

Originally Posted by inigo88

Are you guys hoarding a secret version?

Yes .... ssshhhh ... don't tell anyone :-)

Originally Posted by inigo88

Does anyone have a sound sample of one, or know what they sound like? Is it an actual control channel or just an open carrier sound made up of LTR subaudible data?

It's not a control channel. It serves to continuously transmit the site's configuration, so that roaming mobiles can learn about the site, and self-configure to register and then begin using the site.

The HSC sounds like an open carrier with continuous sub-audible signalling. You'll occasionally get a voice call popup on the HSC, when all of the other traffic channels are busy. You'll also see activity for all of the LCNs on the site show up in the HSC signalling when you run LTR-Analyzer against it.

PM me with an email address and I'll send you a wave file.

[mtindor]

Originally Posted by DSheirer

SlicerWizard said that we can share v3.0 ... PM me with an email address and I'll send a copy.

Denny

If Andrew is looking at this thread: Andrew, is there any chance you can put 3.0 up on your site so that it is available from one trusted place rather than handed down from person to person?

Mike

[DaveNF2G]

LTR-MultiNet's constant subaudible STATUS channel is not designated as a "control" channel, but it performs that function. When using LTRTrunker to follow such a system, it is clear that this channel sends the same kind of instructions to subscriber units as the Motorola control channel - voice channel grants, repeater frequencies, etc.

MultiNet has a HOME channel that keys up whenever any repeater is in use for voice traffic. This channel sends current configuration data, but in my experience does not provide the commands that send my voice scanner to any particular repeater to follow conversations.

LTR-MultiNet also has a system ID like Motorola does.

My setup suddenly became unable to decode Rensselaer County (NY)'s STATUS channel a few months ago. There have been no announcements of system changes (or acquisitions of money to pay for any).

[slicerwizard]

Originally Posted by mtindor

If Andrew is looking at this thread: Andrew, is there any chance you can put 3.0 up on your site so that it is available from one trusted place rather than handed down from person to person?

Mike

You can get the LTR-Net version at Index of /~phoenix/wap/LTR

[Michael-SATX]

Thanks, I just downloaded it and I'm curious when I start LTR-Analyzer it reports v1.8 not v3.0 ?