Ongoing Changes: Marion Co. MECA System

[tbhausen]

OK, I'm taking a risk starting this thread. I know Lou closed its predecessor, and I know why (and for the record I think he did the right thing). However, ongoing changes to the MECA system are a very important subject to a lot of monitoring hobbyists and professionals alike here in central Indiana.

There was actually good and interesting info to be gleaned from the previous morass of a thread. Can we try again to keep this one one topic as the new system is rolled out and we learn about it together?

Todd/Indy

[khthomas1008]

Well said Todd. I think the previous thread had three or four people in a pissing match on who had the most current information. Just post the information you have and we will all find out together whether it's accurate or not. After all, half the fun of this hobby is testing new information. Let's keep the posts positive and get back to enjoying the hobby we all love.

[DiGiTaLD]

I saw it posted on the database page for MECA System 1 that the upgraded system will in fact be a true P25 system using the 9600 bps P25 control channel. If so, that would make it only the second of it's kind in Indiana, after the Mishawaka Public Safety system. It will be very interesting to see how the cut-over is done. I understand that it will not be until after the first of the year. Many agencies still do not have their new radios deployed yet. We do not yet have them, and there are still many, many STX 821s and MTS2000s in service that will have to be replaced with XTS series radios before the cutover to the upgraded system can actually happen.

I am in agreement with both of you guys. This is something that needs to be discussed, because many folks are interested in how the system is going to be changed by the transition to the upgraded configuration. However, it needs to be done without all the BS, fighting, and arguing that was accomplishing nothing. I quit reading the old thread weeks ago because of it. Please, let's not do it again here.

[scannerfreak]

Originally Posted by tbhausen

OK, I'm taking a risk starting this thread. I know Lou closed its predecessor, and I know why (and for the record I think he did the right thing). However, ongoing changes to the MECA system are a very important subject to a lot of monitoring hobbyists and professionals alike here in central Indiana.

There was actually good and interesting info to be gleaned from the previous morass of a thread. Can we try again to keep this one one topic as the new system is rolled out and we learn about it together?

Todd/Indy

No, no risk I asked Lou to close the last thread. I can assure you this one will not suffer the same fate as the other. I tried to help by correcting incorrect statements, as did others, hoping maybe someone would learn something, but was duped in the end.

[w8fcc]

There apperars so be more active talk groups today on Meca if any one wants to listen and log them some that have showen up are
4733
40400
32688
Does any one have INFO on these

[tbhausen]

Time to leave the 396 on at night with ARC396PRO doing the logging and recording (I just can't leave my PSR-500 alone at night). Gonna take me a couple days to figure out how it all works together.

Todd/Indy

[W9NES]

Scanner Freak,I understand that you took my posting off for no reason.Please explain why?

[loumaag]

Originally Posted by W9NES

Scanner Freak,I understand that you took my posting off for no reason.Please explain why?

I am guessing that he took it off for the reason that it had nothing to do with the topic at hand; just as this quoted post is not on topic. You have a problem, take it to PM.

Discuss the changes to the MECA system or the possible start up of the UCON system, but stay on topic.

[loumaag]

Originally Posted by tbhausen

Time to leave the 396 on at night with ARC396PRO doing the logging and recording (I just can't leave my PSR-500 alone at night). Gonna take me a couple days to figure out how it all works together.

Todd/Indy

This is an excellent way to discover new TG's; however, might I suggest you look at IDTrackerII (freeware) instead of using the ARC396PRO logging ability. IDTracker has the ability to only record and/or log the unknowns, saving both your time and hard drive space by ignoring (indeed skipping if so set) the TG's that you have already identified.

[remod]

In doing a comparison of old [MECA] and new [UCONN] frewquencies I come up with about 10 frequencies [used currently by MECA system 1] that are not listed in the new set of frequencies[see old CLOSED posting] These frequencies are as follows:

855.4875
856.7625
857.2125
857.2625
866.100
866.125
866.5375
867.1375
867.5375
868.175

Again all of these are currently in use by MECA and are NOT listed in the new frequency set for UCONN.

I am wondering if these will be used in the new system?

Also, in looking at some other 800 P-25 systems I have noticed that there are many sites listed with each site having anywhere from 4-5 frequencies for use or maybe even 10 or more frequencies. I have seen a map or two showing the new UCONN coverage area and how and or where different sites might be located. I am wondering what the breakdown of frequencies will be for each site and if those frequencies might come from the list of UCONN frequencies that were posted in the old post that is now closed?

Thank You for the help.

[w8fcc]

This MIGHT be the list they will use if they chose to reband if they choose not to they will keep it the same being public saftey they have the option to opt out and keep things the same we will not know till the Application shows up with the FCC. They are using those freqs you listed right now except 855.4875 866.100 866.1250 867.5375 and 868.1750 is now Boone county Safe T Simocast.
This is a POSIBLE LIST not a fact just possible list if they reband This list also shows what UniTrunker has shown over the last few months as well


851.8375
851.8875
852.1125
852.5125
853.6000
853.6500
856.2125
856.9125
856.9375
857.2625
857.7625
857.9375
858.2125
858.2625
858.7625
858.9375
859.2625
859.7625
859.9125
859.9375
860.2625
860.7375
860.7625
860.9375
860.9875
861.9125
861.9625
863.4375
863.6375
864.8375
865.2375
865.4125
865.6625
865.7125

[tbhausen]

Thanks guys. Lou, I'll look into that.

Todd/Indy

[DiGiTaLD]

Originally Posted by remod

Also, in looking at some other 800 P-25 systems I have noticed that there are many sites listed with each site having anywhere from 4-5 frequencies for use or maybe even 10 or more frequencies. I have seen a map or two showing the new UCONN coverage area and how and or where different sites might be located. I am wondering what the breakdown of frequencies will be for each site and if those frequencies might come from the list of UCONN frequencies that were posted in the old post that is now closed?

MECA is currently a simulcast system, meaning that all of the transmit sites transmit the exact same traffic on the exact same frequencies at the exact same time. Transmitters are precisely time synchronized so that they do not mix destructively in receivers and interfere with one another. All of the receivers in the system (both at receive only and receive-transmit sites) receive signals from subscriber radios, and send their respective audio signals to a comparator. The comparator decides which signal has the best signal-to-noise ratio and sends it on to the system controller and then the transmitters to be sent out on the proper talkgroup. I'm sure there are a bunch of minute details I've left out, but that's basically how it works.

To a subscriber radio on MECA, (and to our scanners) it looks as if there is only one site on the system. That's why with the current MECA database information, there is only information for one site, when, in reality, there are actually several sites set up in SmartNet simulcast fashion. Thus, we don't see any of the stuff we do in a SmartZone system, such as multiple site numbers, different frequencies for different sites, and so on.

I don't think there is any reason to believe that the upgraded system will be any different. Based on the information published in the database that the upgraded system will in fact be a real P25 system using the 9600 bps control channel (whereas a proprietary Motorola SmartZone system uses their 3600 bps control channel), I think it will probably be a P25 system set up in a simulcast fashion. Having the system utilize different frequencies for each site would dramatically increase the number of frequencies required to support the system. Subscriber radios would have to constantly roam between sites. In a system with multiple networked sites not set up in simulcast configuration, you'd also have the issue of which frequencies you want your receive-only sites to be receiving. Receive-only sites work much better in a simulcast system because there is only one set of system input frequencies to receive, no matter how many transmit sites you have, because everything is on the same frequencies systemwide, all at the same time.

I think all of this points to an upgraded system that will be P25 simulcast.

[tbhausen]

Thanks for taking the time to write that--very good info.

Todd/Indy

[loumaag]

And, if the new (P25) system does in fact maintain the simulcast; you may want to research a bit in the IL forum (and some others) reference the difficulty in monitoring simulcast digital signals.

[DiGiTaLD]

Originally Posted by loumaag

And, if the new (P25) system does in fact maintain the simulcast; you may want to research a bit in the IL forum (and some others) reference the difficulty in monitoring simulcast digital signals.

There are several areas in Indiana where several Project Hoosier SAFE-T sites are tied together in a simulcast fashion (effectively functioning as one site). I've had no trouble monitoring P25 digital modulation on those thus far. Hopefully such will be the case with the MECA upgrade.

[kadetklapp]

Well, DiGiTaL must be doing all the right things. I have a tremendous amount of problems monitoring the Boone County Simulcast system. All the sites are tied together. I can't pick ANYTHING up on the Boone County tower freq at all. The only traffic I hear, when it does trickle thru, is off the Crawfordsville tower. And even then it seems it's usually medical. I rarely will pick up Boone County Sheriff Dispatch. Even with the scanner in the town of Thorntown, I hear nothing, unlesss it comes over Crawfordsville's tower.

[GTO_04]

Originally Posted by loumaag

And, if the new (P25) system does in fact maintain the simulcast; you may want to research a bit in the IL forum (and some others) reference the difficulty in monitoring simulcast digital signals.

THAT'S what I was afraid of! There were also issues monitoring the Michigan State System (MPSCS), more specifically in the Detroit area.

GTO_04

[scannerfreak]

Originally Posted by DiGiTaLD

There are several areas in Indiana where several Project Hoosier SAFE-T sites are tied together in a simulcast fashion (effectively functioning as one site). I've had no trouble monitoring P25 digital modulation on those thus far. Hopefully such will be the case with the MECA upgrade.

Two completely different set-up's. Motorola P25 simulcast systems use Linear Simulcast Modulation, CQPSK, which is very difficult for the current scanners to decode. Granted, reception is best when inside the coverage "foot print" so those in that area will be better off than those not. But from someone who monitors a P25 CQPSK simulcast system every day, don't get your hopes up

[tbhausen]

Anybody try monitoring the Boone Co. SAFE-T simulcast with a GRE 500 yet? Guess I oughta do that. I'll program it up and have a listen today.

Todd/Indy