Can someone explain the StarCom21 System?

[drksky]

Or point me to a site that does so succinctly?

I've using ARC396 for and getting the frequencies from RR (I'm in Bloomington), but I'm confused about the apparent disconnect between frequencies and talkgroups. I can get lots of traffic on the B/N frequencies, but if I have ID search on, I'm seeing a lot of TGs for ISP Dist. 6, 8 and 9. Is this simulcast traffic? However if I put in the frequencies that are listed for Pontiac (assuming those are for Dist 6), and the TGs for Dist 6, I get no traffic.

From the RR database, how do I know what frequency sets I match to what talkgroup sets?

Any help would be greatly appreciated.

Thanks

 

[seberry]

Unfortunately, I am not from your area nor am I familiar with your system. I do know, however, that with many multi-site systems, there must be a radio affiliated with a site for the talkgroup to be broadcast on that site.

For example, there are sites A and B let's say. The county jail is located really close to site A. You are probably never going to hear the jail's talkgroup on site B unless someone from the jail is traveling and their radio affiliates with B.

I hope this helps a little bit. Geography plays a huge role with this stuff.

 

[Awesomeman92]

Yes the ISP talkgroups you're getting are simulcasts of the area districts. I'm assuming since you're getting Bloomington and Normal traffic you're listening to site 229 (Normal). I'd be surprised if you got anything on the D6 Pontiac HF-2 channel, but TG 13000 (D6 Dispatch A) is very active from that site. To explain it as simply as it can get, it an interconnected P25 trunked system, but not all the users are on more than one tower, it just depends on the user. I wouldn't even bother plugging in the VHF/UHF frequencies for B/N or ISP, they're all on Starcom except for the County (METCOM) Fire and Bloomington Fire.

 

[drksky]

Yes, I am using the Normal frequencies and the talkgroups for the B/N PD & fire, but I was confused when using ID Search and seeing TGs 13000, 13002 and 13004, which are the A dispatches for ISP 6,8, and 9.

So you're saying that from where I am I probably won't even hear the frequencies for the actual ISP districts? Is there a listing somewhere of these sites (like 229) with a cross-reference of the freqs and talkgroups? That's the biggest problem I'm having with the RR database is there's a total disconnect between the frequency and TG lists.

I know Normal fire is on StarCom, but I think that Blm fire is still using their HF radios.

 

[drksky]

Ok, I think I see in the DB where the site names come from. Normal is 2-029, right?

So how do I know what site freqs go with what talkgroups?

 

[Awesomeman92]

If I understand your question right, you're asking if you can get the D6 HF-2 old dispatch channel (154.695). The answer is no, ISP has been on Starcom exclusively and basically dead on HF for about 5 years now, the only non-trunked channels I've ever heard used are D8 Peoria's HF-2 channel for occasional announcements, ISPERN, I-REACH, and a couple simplex car-to-car channels up around Chicago. They do however still have the HF radios, during an outage of SC21 they revert to the HF channels, and if they do, Normal is a transmitter location for D6, you would be able to get it. Nowhere I know of has a list of all talkgroups on the sites (it would be really nice, though) but the list of sites and frequncies is here StarCom21 Statewide Illinois P25 Trunking System, Statewide, Illinois - Scanner Frequencies. And yes, Bloomington FD is still on VHF. Also, a good general guide to the SC21 system is here http://www.carmachicago.com/profiles/StarCom21.pdf

 

[Awesomeman92]

Ok, I think I see in the DB where the site names come from. Normal is 2-029, right?

So how do I know what site freqs go with what talkgroups?

Right. And any talkgroup can be on any frequency on the site at any time. They don't have a specific frequency just for themselves.

 

[drksky]

No, no, I'm not trying to hear any of HF stuff, I'm trying to figure how to cross reference the StarCom sites to what talkgroups are on that site. Sure, I guess I could just put the whole damned system into my scanner and have it pick up whatever it picks up depending on where I am.

 

[drksky]

Right. And any talkgroup can be on any frequency on the site at any time. They don't have a specific frequency just for themselves.

That I understand, but what talkgroups go with what site (well, other than just listening to the sites, which isn't always possible)? Some of them are obvious, like the Normal site and the McLean Co talkgroups, but others, like the ISP districts, not so much.

 

[Awesomeman92]

All you have to do is just program in the Normal site. All the talkgroups you'd need around B/N will be on that site.

 

[n5ims]

Ok, I think I see in the DB where the site names come from. Normal is 2-029, right?

So how do I know what site freqs go with what talkgroups?

The only way to know what site freqs go with what talkgroups is to know (in real time) what radios on those talkgroups are affiliated with what sites (which in reality only the system controller knows). For example, say you're in Springfield and are listening to the local site there. You'll mostly hear the talkgroups that are from the Springfield area and very little from other areas around the state, although they're part of the overall system.

Let's say that there's an emergency meeting in Springfield and folks from Chicago, Rockford, Moline, Peoria, and East St. Louis drive their police cars down for that meeting. You may start hearing traffic from talkgroups in one or more of those areas as those folks arrive and check in with their local folks using their radios. You'll hear that traffic even if the folks that drove to Springfield never transmit, but have their radio on and tuned into their local talkgroup in question. If they turn off their radio or tune it to another talkgroup, you'll stop hearing that traffic.

 

[WayneH]

Moved to the IL forum. drksky, please review the Stickied threads at the top of a forum before creating a thread. They instruct you on what and where to post if applicable. That way you get a better answer when your question is in the right place.

GenScan Sticky: http://forums.radioreference.com/general-scanning-forum/61006-please-read-before-posting-forum.html

 

[drksky]

The only way to know what site freqs go with what talkgroups is to know (in real time) what radios on those talkgroups are affiliated with what sites (which in reality only the system controller knows). For example, say you're in Springfield and are listening to the local site there. You'll mostly hear the talkgroups that are from the Springfield area and very little from other areas around the state, although they're part of the overall system.

Let's say that there's an emergency meeting in Springfield and folks from Chicago, Rockford, Moline, Peoria, and East St. Louis drive their police cars down for that meeting. You may start hearing traffic from talkgroups in one or more of those areas as those folks arrive and check in with their local folks using their radios. You'll hear that traffic even if the folks that drove to Springfield never transmit, but have their radio on and tuned into their local talkgroup in question. If they turn off their radio or tune it to another talkgroup, you'll stop hearing that traffic.

Ok, so let me ask it this way. How do others program their scanners? Do they mostly just program the site freqs and not worry about identifying what talkgroup numbers are what actual groups?

 

[Awesomeman92]

Ok, so let me ask it this way. How do others program their scanners? Do they mostly just program the site freqs and not worry about identifying what talkgroup numbers are what actual groups?

How mine is set up is I programmed in the site channels for the Normal site, then I programmed in the talkgroups I wanted to hear, and then made a separate group that would show me any other talkgroups I didn't have programmed in. It's the best way I've found to do it on my Pro-197. As far as talkgroups, I'd go with all the B/N TG's, McLean County, and ISP D6, D8, and D9. Those consistently come in.

 

[Awesomeman92]

That I understand, but what talkgroups go with what site (well, other than just listening to the sites, which isn't always possible)? Some of them are obvious, like the Normal site and the McLean Co talkgroups, but others, like the ISP districts, not so much.

It really just depends, the sites inside a district will always have it (like Normal always has D6 on it). The rest really just matters what radios are in range of what towers. From Normal just off the top of my head I've gotten DChicago, D2, D5, D6, D8, D9, D10, D15, D17, and the Air units. Then there's also all the statewide emergency talkgroups, which aren't really worth programming in unless there's a major event going on. It really just depends on the day you're listening and who's around you, there's no real way to tell which talkgroups (other than the immediate area districts like 6, 8, and 9 and local users) will be on the site on a given day.

 

[n5ims]

While I can't say specifically for the StarCom21 system, here's how I have similar systems programmed. Program in the site nearest to you along with all talkgroups you're interested in (or simply use a wildcard, open system, or however your scanner has you select all talkgroups if you simply want to hear everything going on).

You could also program in additional sites that are nearby or along your normal travel route, if that's appropriate for you, but be aware that your scanner may lock onto that site, not your local one depending on how your scanner works. If this happens, you may miss some local traffic and hear what's happening on that site. If your scanner has a roam selection this may help as would connecting a GPS to your scanner if that is available as well (some scanners have this option and will select the appropriate site based on your GPS location).

Programming all sites on a system isn't always the best policy since your scanner will search through them all (even if they're way too far away to pick up any signal) when looking for the control channel. It's also possible that a large system may have a frequency used on multiple sites or have enough frequencies to exceed the limit on your scanner. Normally this isn't an issue since you rarely have a need to program every frequency in a system (you generally only need those nearby or close to your travel route and will have no need to program those in areas you rarely or never travel through).

 

[drksky]

Thanks for all the replies. For the time being, I've just added the B/N site (229) and the talkgroups assiciated with that are, as well as added the 6, 8, and 9 dispatch A TGs. Also added the Dist 6 site (I'm assuming the Pontiac site) and it's talkgroups since I don't really do a lot of traveling around.

 

[Awesomeman92]

Thanks for all the replies. For the time being, I've just added the B/N site (229) and the talkgroups assiciated with that are, as well as added the 6, 8, and 9 dispatch A TGs. Also added the Dist 6 site (I'm assuming the Pontiac site) and it's talkgroups since I don't really do a lot of traveling around.

I'd put in all the talkgroups for districts 6, 8, and 9, they all (normally) come in on Normal. I wouldn't use the ISPERN patches though, they usually don't use them. 99% of the time they're on the regular dispatch channels with ISPERN traffic around here. The I-REACH patch isn't active either.

 

[gewecke]

Yes, I am using the Normal frequencies and the talkgroups for the B/N PD & fire, but I was confused when using ID Search and seeing TGs 13000, 13002 and 13004, which are the A dispatches for ISP 6,8, and 9.

So you're saying that from where I am I probably won't even hear the frequencies for the actual ISP districts? Is there a listing somewhere of these sites (like 229) with a cross-reference of the freqs and talkgroups? That's the biggest problem I'm having with the RR database is there's a total disconnect between the frequency and TG lists.

I know Normal fire is on StarCom, but I think that Blm fire is still using their HF radios.

This is correct, Blm fire is still on vhf. You may also want to program in the conventional MABAS and ITAC and UTAC channels,as they are in the new B/N area radios. The old UHF BPD repeaters are still online, but it seems to be for a contingency.
Enjoy!

73
n9zas

 

[N9JIG]

Or point me to a site that does so succinctly?

I've using ARC396 for and getting the frequencies from RR (I'm in Bloomington), but I'm confused about the apparent disconnect between frequencies and talkgroups. I can get lots of traffic on the B/N frequencies, but if I have ID search on, I'm seeing a lot of TGs for ISP Dist. 6, 8 and 9. Is this simulcast traffic? However if I put in the frequencies that are listed for Pontiac (assuming those are for Dist 6), and the TGs for Dist 6, I get no traffic.

From the RR database, how do I know what frequency sets I match to what talkgroup sets?

Any help would be greatly appreciated.

Thanks

To understand StarCom21 you need to understand the basics of trunking as it relates to scanners.

Trunking systems take a set of frequencies and shares them among all users. While in the past you may have had a couple police freqs, a fire channel and a channel for the road department and another for the dog catcher, a trunked system puts these all in one pool of available channels.

When a user wants to talk he presses the talk button and speaks. The radio, in a fraction of a second, sends the radio identifier to the system's controller (a computer) and assigns the user's radio and any other radios that are members of his talkgroup to a channel on the system.

StarCom21 and other wide area networked trunked systems takes this a step further. Since the State of Illinois is much too large to cover with a single site, they built hundreds of them all over the state and connected them with microwave links and phone lines. This allows a user in one town to talk to a user in another town miles (or hundreds of miles) away.

For you and your BCD396T you would look at the resources here on RadioReference or in the CARMA profile at http://www.carmachicago.com/profiles/StarCom21.pdf and select the towers that cover the area you are in. For Bloomington I would select Towers 229 and 231, and maybe 202 as well. Put each in a System and then monitor each of these 3 Systems.

Since the BCD396T does not support trunking 'Sites' like the BCD996T, BCD396XT or BCD996XT do, I would suggest that you create a Group in one trunking system that has the talkgroup labels for your area (McLean, Normal, Bloomington and District 6), then copy and paste the entire System and change the System Name to the other Towers and then edit the freqs to match the second (then third etc.) tower you want to monitor. (FYI, the BCD996T and both the XT digital scanners support something called Site trunking. This would allow you to program the talkgroup lists once and enter in multiple Sites that share the Groups.)

Remember that with the Uniden scanners that if you SCAN a trunked system you will only hear the Talkgroups that you have programmed into Groups. If you SEARCH a trunked system you will hear all activity, but only the ones in your Groups will have labels attached. So if you have 13000 programmed as District 6 State Police it will show up as that when there is activity, but if you do not have that labeled it will just show up as 13000.