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 Post subject: LTR Analyzer
PostPosted: Thu Jul 09, 2009 7:52 pm 
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Joined: Mon Jan 03, 2005 1:17 am
Posts: 2645
Location: Bellevue, WA
Anyone try this with their d-tapped scanner?

I'm testing out "LTR Analyzer" on the Bellevue Place system. So far, the program works pretty good. Still trying to understand how LTR works but I think I understand the basics.
It's not as fancy as PDW.

Here's a typical stats output from a few minutes of monitoring.

LCNs seen: -- 02 -- -- -- 06 -- -- -- 10 -- -- -- 14 -- -- 17 18 -- --
Monitored: -- 02 -- -- -- -- -- -- -- -- -- -- -- -- -- -- 17 -- -- --

Groups seen: 02-055 02-102 02-125 02-139

| Avg sampling rate: 22050 Hz Modulation: 71% LTR Modulation: 17%


EDIT: Here's the link: http://home.ica.net/~phoenix/wap/LTR/


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 Post subject: Re: LTR Analyzer
PostPosted: Fri Jul 10, 2009 12:36 am 
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Joined: Thu Oct 04, 2007 1:58 pm
Posts: 3429
Location: Not in Alaska
Here's what I got from a day or so of listening. I'm not within range, otherwise I'd be monitoring it.

Image

The "part" column means that I've confirmed it to be part of the Bellevue Place LTR system. At least one of those belongs to the Waste Management system.


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 Post subject: Re: LTR Analyzer
PostPosted: Fri Jul 10, 2009 1:13 am 
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Joined: Mon Jan 03, 2005 1:17 am
Posts: 2645
Location: Bellevue, WA
Yup, looks good except for LCN08. I'm pretty sure LCN 08 doesn't exist. It's actually LCN 09 @ 463.575mhz

My decoding from home initially told me it was LCN 08 but after after letting the software sit on that freq for a while, it seem to conclude it was LCN 09. I'm wondering if the lack of a "perfect" signal could cause slight decoding errors.

BTW, I think Microsoft uses a LTR system. It has symptoms of a LTR set up. I can hear traffic over the freqs but I think I need to be on campus to decode the LCNs.


Last edited by nickcarr on Fri Jul 10, 2009 1:14 am, edited 1 time in total.

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 Post subject: Re: LTR Analyzer
PostPosted: Fri Jul 10, 2009 1:14 am 
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Joined: Thu Oct 04, 2007 1:58 pm
Posts: 3429
Location: Not in Alaska
I think it's LTR Passport.


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 Post subject: Re: LTR Analyzer
PostPosted: Fri Jul 10, 2009 1:14 am 
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Joined: Mon Jan 03, 2005 1:17 am
Posts: 2645
Location: Bellevue, WA
Damn, so we can't decode it using our scanners?


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 Post subject: Re: LTR Analyzer
PostPosted: Fri Jul 10, 2009 5:56 am 
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Joined: Wed Jun 09, 2004 4:15 pm
Posts: 1654
Location: Destination Unknown
Nope. I doubt we will ever see a scanner for Passport.

It's not really called "LTR Passport", rather it is simply "Passport".

Trident Micro Systems made (and still makes) LTR controllers, and along the way they developed a proprietary protocol that functions similar to LTR in the sense that it uses a subaudible control word, however they completely re-wrote the word to provide enhanced features over LTR.

The only way you will "scan" it is with an Aeroflex service monitor with Passport option, and even then you are not really scanning, you are listening to one channel at a time.

It is a pretty cool protocol feature wise, and the switch (site controller) is designed to work with a digital RF layer, which I also understand is in the making. Currently, audio is digitized as soon as it enters the switch (any switch in the network) and remains digital as it passes through the network, only being converted back to analog when it exits a switch and enters a transmitter. Once the digital RF layer is complete, that will go away.


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