2016-Starcom21 Thread Sites/Talkgroups
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Probably. That would make the most sense anyway.
I haven't been inside the actual floor of NWCD since around the time they first combined assets with site 115 and the system was still fairly new then to them, so no one really knew much about it. I had raised concerns with running FDMA along with TDMA on a site that large-dispatch was still all TDMA at the time-and they didn't really seem too concerned about capacity. I still have my doubts, especially with how much FDMA they run on that site now. I've seen what happens to 149 when it just snows 5 inches, it's going to be really interesting if something big were to happen.
Which is exactly as I said above. It takes only one affiliated radio in FDMA mode to make it all FDMA. If the dispatch radio, be it a console or automated dispatcher, is FDMA the rest go into FDMA mode.
I have also heard from inside NWCD that they did not like the way TDMA sounded so programmed their radios to FDMA. I heard varying stories, some were because of the air-pack masks and some were just the sound of the radios in general. Take all these with a grain of salt, they said the same thing when the original digital radios were introduced years ago.
As a former BGFD Fire/Medic we had issues with intelligibility even in the old analog/pre-narrowband VHF days when masked, it only gets worse with narrower bandwidths and with digital, I suspect it was worse yet with TDMA.
I suspect that there are a variety of reasons they system has not totally transitioned to TDMA yet but that eventually all these will be worked out and the transition will be completed. They need the added capacity as more and more agencies use the system. There are a dozen more suburban agencies coming on board soon and no new freqs coming with so SC21 will not let FDMA remain on Site 149 for long.
Which is why I'm surprised the state allowed them to combine the sites. Sites 149 and 115 separately probably could've handled all the additional traffic, just needing 115 to be upgraded to TDMA. Was there ever any official word on why that consolidation took place?
Here are SC21 talkgroup names mentioned for Barrington Countryside Fire Protection District in NWCD's Executive Committee on 9/19/2013:
Barrington FD, Barrington PD, Barrington FD/PD, BCFPD FD, BCFPD TAC1 & TAC2
There are 333xx-series talkgroups listed for Barrington PD in the "new" Lake County SC21 plan, but it would appear that the talkgroups mentioned above would have existed (and have been active?) in 2013. Can anyone provide talkgroup numbers to go with the above talkgroup names??? Nothing else found on Radio Reference.
I don't think it would have made a lot of difference if they had used a separate Site for NWCD, in fact it actually would have had less capacity since there would have been another control channel. They just added the NWCD freqs to the existing site, that allows one more voice freq, or 2 talk paths when TDMA is used.
They did the same thing for DuPage, added more channels to the existing site. I think the same is going to happen for Lake County (108) as well.
McHenry County however was a different story. The infrastructure is separate, owned by McHenry County. Only McHenry County activity occurs on it and McHenry County units do not normally affiliate on the parallel SC21 Site and other users do not normally affiliate on the County site. I suppose there could be a setting where if one site or the other fails then the remaining site will take over but don't know that for a fact.
Had NWCD, DuPage or Lake purchased their own infrastructure they would have likely had a separate parallel Site ID like McHenry County.
By clogging (for lack of a better term) up the TDMA talkpaths that - at least at the time - were exclusive to 149 with FDMA from 115 you eliminate that advantage though. If everyone across the board was using TDMA, then it would make more sense to me. But by combining both phases onto one site you limit the capacity. Now obviously NWCD is using FDMA so it's a moot point, but it just doesn't make much sense. Hopefully it doesn't, but if some kind of terrorist or major event were to happen in the city, the system would be jammed with traffic related to that since SC21 is the official interoperability platform for the state. Since everyone is using FDMA, there's going to be significantly less TDMA talkpaths available for NWCD than there would be if the sites were separate.
When ISPERN is being broadcasted. Most agencies will broadcast ISPERN over a main dispatch channel. Or dispatch will say please stand by for simulcast unless you have an emergency. Now on starcom 21 there is a channel set to ISPERN. My question is if my department is on starcom 21 and my dispatch dosen't simulcast ISPERN. Does the radio automatically play the ISPERN talk group?
VASCAR2
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Prior to the consolidation of the ISP dispatch centers ISPERN was patched directly into SC 21 TG. To my knowledge this has not changed. Theoretically a car on VHF could transmit on 155.475 and talk to another unit on the SC21 ISPERN TG without a Telecommunicator doing any patching on the console. There are specific SC 21 ISPERN TG's for each District which requires a SC21 user to be scanning the specific ISPERN TG or select the ISPERN TG. When working outside your assigned District, Troopers are advised to use the Dispatch/District for where they are physically located. The example would be a District 11 Trooper being assigned to work in District 9 patrol. The District 11 Trooper should utilize TG 9A and scan District 9 ISPERN TG.
The intention of the ISP was to cease using VHF High and Low band radios with the adoption of SC21. There was pressure from rural areas for ISP to maintain mobile radios on VHF High band so Troopers could communicate with local agencies. I heard ISP had no funding set aside to purchase new VHF Highband mobiles due to narrow banding making existing mobiles obsolete. Supposedly homeland security kicked in some money and ISP purchased Icom VHF Highband mobiles for rural District Troopers. When a Trooper still has a VHF mobile which scans ISPERN it is not necessary to scan the SC21 ISPERN TG.
Prior to consolidation Telecommunicators could patch IREACH VHF into SC21. There are only two active TG's in a District that do not require affliation, the District primary Dispatch channel for Example 9A and District 9 ISPERN. The only way a Trooper can hear another Trooper on the District Car to Car SC 21 TG is if they both are physically voting on the same tower or both have their car to car TG selected to transmit on the Car to Car TG. You can be looking at the other Trooper and try and talk to the other Trooper on Car to Car but unless you both are voting the same tower the other Trooper will never hear you calling him even though he is scanning the Car to Car TG. This and the lag time it takes to switch TG's is very aggravating for anyone who has used conventional simplex or duplex radio systems.
I would assume in a local agency there are only the primary dispatch channel(s) that always transmit on SC21 regardless of a unit being affiliated and ISPERN. Any other TG to transmit on a tower requres affiliation. This is done to keep from over loading any trunked radio system and to lesson the need for frequencies required for the trunk system. The key to be able to hear SC 21 ISPERN TG is to have the mobile or portable radio on scan and to be scanning the ISPERN TG. Unfortunately many users of mobile radios are not concerned with knowing how to use the features on various radios. A very high percentage of users only know how to turn the radio on, know where the volume knob is and how to use the microphone.
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It doesn't actually work that way. It usually doesn't matter what tower you are affiliated with as long as you are affiliated with the talkgroup.
The only time it matters is when your agency or that particular talkgroup is restricted to a certain set of towers. SC21's pricing levels are different when you choose a statewide, regional or local plan and (if SC21 actually has it set up) you have a local or regional plan your radio will only affiliate on the towers you are authorized on. This is how they are able to segregate the McHenry County users for example.
If 2 ISP cars are on the same C-C talkgroup but affiliated to different towers then they should still be able to communicate.
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I think the original plan was for the entire site to go TDMA and have NWCD act as a guinea pig to make sure it worked sufficiently well. When issues came around they did not force other users into TDMA, at least not yet.
Even if the system was only FDMA, by adding the NWCD channels to the mix you still save an additional voice path with the same number of freqs by not having the additional data channel.
Also remember that for every TDMA conversation there is one less voice channel being used so even a mix of FDMA and TDMA saves resources and adds voice paths.
Right. But when the site uses probably 70% FDMA, the actual spectrum saved is minimal, even when considering the 3 extra voice paths gained by eliminating a control channel. Just by technological limitations you're cutting total capacity by up to 2/3 by having both modes on the same site. Of course this is theoretical, since it's unlikely every frequency would have FDMA traffic on them simultaneously and so that loss would be realistically less than 2/3.
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. 73, n9zasI had a chance to run Pro96Com against T149 a couple of times last week. It seems like most, if not all, of the NWCD dispatch talkgroups, both fire and PD, are in FDMA mode. The only TDMA stuff I logged were some local PD "Patrol" channels and public works and whatnot.
Speaking of TDMA I ran Proi96Com for awhile on T502 (Cook County South). I found one TDMA talkgroup in use - 25042 (Fugitive Search South)
Speaking of TDMA I ran Proi96Com for awhile on T502 (Cook County South). I found one TDMA talkgroup in use - 25042 (Fugitive Search South)
jpm
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MTPR eng 13 mutual aid to GLVW this am and on the TDMA mode. Shows up as PT1 on the 996p2. So that tells me the FDMA mode is because of Robotic Robin terrible sound. I did listen to PALT fireground during a fire ground operation house fire and was able to understand communications from the SCBA masks.
Got a hit on TG 26017 earlier today off site 224. Assuming this is a Muscatine IA TG. Didn't catch a RID or voice traffic, and it was only a single hit, but it was new to my log.
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