Trunking System Aliasing

unleashedff248 · #1 (**permalink**) 11-04-2007, 08:44 PM

I went to go reprogram my XTS3000 and was playing around with a trunking system already in the radio. Seems I can't get rid of it without the system key. I'd like to delete it without getting rid of the other info, any way to do this?

The other thing I noticed is the system ID aliasing function. From what I understand, this allows someone with a system key of ABCD to monitor any system of ID ABxx. The limitation is that you CANNOT transmit on this system, no matter what you do.
SO, if I understand correctly, my home system, BD01 (Motorola Smartnet type II), can be monitored by setting up a system with a system key of say BD99, programming all the right info in for the BD01 system, and checking Alias on the general tab for the system. This way, my people would be able to receive on the system, but not transmit. Transmitting would still be done on the apparatus radios.

A little background: The system is a FIRE/EMS ONLY system, no police, no secure/sensitive information. The entire county is moving over to this from a single low band channel. It is important for units in the field to be able to hear apparatus responding and other general comms on the system. However, the county has only issued departments limited radios due to budgetary restrictions right now. For example, we have only 2 portables.
I would like to have our firefighters and EMT's to be able to listen, but not transmit. The portables are currently used for conventional fireground channels, and scanners would be expensive and a little ridiculous to carry on a fireground.

Is this a reasonable idea? The problem is I would need to find a system key with BDxx, I don't want to use the actual key since this would enable transmitting. I tried the Batlabs creation primer and the CPS doesn't like the homemade keys. TX inhibiting would be bad since other trunking systems are programmed in some radios that need transmitting left intact. So what does everyone think??? Just to clarify, nobody's transmitting on a system which they are not authorized. In this case everyone's authorized, but we just don't need people playing, you know?

Thanks!

KS4VT · #2 (**permalink**) 11-04-2007, 09:21 PM

Ask your system admin. to create a single ID that has the transmit funtion turned off in the controller then create another system in the radio that uses this ID and tie those talk-groups that you don't want TX capabilities on to that system. Doing this will allow for you to monitor whatever TG's you put into it and should the radio get lost or stolen it can still be inhibited.

Don't play with puttin in obscure ID's and system's. It's not worth putting the system or it's users at risk.

ElroyJetson · #3 (**permalink**) 11-04-2007, 09:32 PM

Batlabs has directions on how to home-brew a system key, too. If you did that, you'd have the key you need to delete the system data. But you can't delete the LAST system from the radio. One trunked personality has to be left in the radio.

However, it can be a system that doesn't exist.

OR...you don't have to connect that system data to any personalities in the radio.

Alternatively, the radio shop that handles the system in question will be happy to delete
that system info from your radio. For security's sake, I'm sure they'd gladly do that, and
no trouble would come of it.

Elroy

unleashedff248 · #4 (**permalink**) 11-04-2007, 10:02 PM

Quote:

Originally Posted by KS4VT

Don't play with puttin in obscure ID's and system's. It's not worth putting the system or it's users at risk.

I already read plenty on putting in console ID's and the such. I'm not planning on doing that. It seems that Motorola designed this function for monitor only use when dealing with trunking systems. As for getting the ID set up, I can try that, I'm just not sure what they'll think of the idea. The system is new, and I'm not sure that they'll go for changing things anytime soon. I just figured this would be much much easier.

As for creating homebrew keys, I can't seem to get the Batlabs info to work with the Astro CPS. I can make the keys but the CPS won't load them. Has anyone gotten this to work? I'd like to try it out before I go and bring it to the county.
People listening isn't an issue. We've been told what scanners to buy and how to put them on the system. I just want to make sure these radios don't transmit on the system at all but can monitor, and I figured this would be a decent and safe way to do that.

KS4VT · #5 (**permalink**) 11-05-2007, 06:06 AM

Being your a legal user IMO it's really not worth all the effort. I fit the definition of the "county radio admin." and would have no problem with setting up such an ID that I described earlier if someone like yourself asked officially, but hey it's your decision and time.

As for homebrew keys, the only thing that I can think of is that maybe the radio was programmed with the "advance system key" the last time and this makes a radio ignore the older style key from that point forward and I've never heard of the "system monitor feature". If it was available I'm sure it would of been published somewhere to include Batlabs. Things like that don't remain secure for very long.

unleashedff248 · #6 (**permalink**) 11-05-2007, 09:06 AM

Maybe I'm misinterpreting it...

Type II/IIi Alias

(Trunking System, General)
DEFINITION:
Enables the radio to ignore the last two (of four) System ID digits, therefore the radio is able to listen to other systems having the same first two System ID digits as the first two digits of the currently selected System ID. This feature applies while operating on the current Trunking System.

WayneH · #7 (**permalink**) 11-05-2007, 06:36 PM

Creating system keys from scratch only works with real old software (Maxtracs, etc). The newer stuff knows better.

KS4VT has the best idea. Messing with Sys ID alias isn't really meant for the application you want to use it for.

GEMOTO · #8 (**permalink**) 11-06-2007, 07:05 PM

Quote:

Originally Posted by unleashedff248

Maybe I'm misinterpreting it...

Type II/IIi Alias

(Trunking System, General)
DEFINITION:
Enables the radio to ignore the last two (of four) System ID digits, therefore the radio is able to listen to other systems having the same first two System ID digits as the first two digits of the currently selected System ID. This feature applies while operating on the current Trunking System.

What system is this? I live in Quincy and know of no Fire/EMS trunking system in the area?

unleashedff248 · #9 (**permalink**) 11-06-2007, 07:15 PM

It's not in Massachusetts, it's in New York. I have two homes right now, one in Weymouth MA, the other in New York.

Turns out that we're gonna try it out first on a spare channel just in case anything goes wrong. Admin seems to like the idea. He's a little aversive to the talkgroup idea, but said he realizes the importance and it's always an option. Thanks for the help everyone.

Now if I could only get my hands on a MCS2000 UHF high Model 3 codeplug...anyone???

Thanks,
Dave