MPSCS Discussion 2012 (CLOSED)

[rdale]

Dimondale. Fairly intermittent so must be when they are on the east side of the county.

 

[SCPD]

A couple of questions

... All of the simulcast systems on the MPSCS, have the ability to use the "Dynamic Sharing Arrangement" (Hereafter: DSA) feature ...For instance, the Washtenaw County Simulcast System is fully loaded and a public safety unit keys up at a major fire scene in Northfield Twp. on one of the Interop talkgroups, but all of the frequency pairs are in use. The site controller will check with all of its neighboring sites, and take a pair that is not in use. In this case one pair from the nearby Northville site so the transmission would be relayed to the other units on the Washtenaw County Simulcast System. If the heavy traffic continues, one of the next transmissions could take place on a frequency pair normally assigned to the Adrian, Howell, or Munith towers thanks to the DSA programming ....

I didn't quote your whole post. I don't know a whole lot about how the sites are programmed, so bear with me if these questions seem silly:

So I'm under the impression that there is a set of frequencies programmed into the Washtenaw (or any other) simulcast system.
When the system goes and borrows a pair from a neighboring site, is the system programming itself with the new pair?
Or are all the neigboring pairs already in there?
I think you kind of know what I'm asking. Are sites software programmable on the fly for whatever freqs they may need?

 

[sdomin]

Mason county has had new talkgroups for a while now, but i am not able to find them at all they are fire ground 1, 2, and 3, and also each fire department has their own proprietary talkgroup. does anyone know how long it takes for these to post on RR? there is one department that got their own talkgroup about 9 months before the county decided to get all departments their own talkgroup. any ideas or help would be great.

 

[ffexpCP]

As long as it takes for someone to identify it it and send it to us.

 

[sdomin]

Ok, thanks

 

[Thunderbolt]

So I'm under the impression that there is a set of frequencies programmed into the Washtenaw (or any other) simulcast system.
When the system goes and borrows a pair from a neighboring site, is the system programming itself with the new pair?
Or are all the neigboring pairs already in there?

There are a few frequency pairs that are programmed into each simulcast system from neighboring counties. Every single site on the MPSCS can handle up to 28 frequency pairs, 30 at simulcast sites. All of these sites are interconnected via a high-speed digital microwave backbone. When all of the assigned frequency pairs on a simulcast system are in use, and public safety subscriber radio keys up, the site-controllers will borrow a frequency pair from a neighboring tower site if needed. Since all of the mobile and portable radios follow the control channel, they will automatically switch to the channel assigned for that radio transmission.

73s

Ron

 

[SCPD]

Thanks

There are a few frequency pairs that are programmed into each simulcast system from neighboring counties. Every single site on the MPSCS can handle up to 28 frequency pairs, 30 at simulcast sites. All of these sites are interconnected via a high-speed digital microwave backbone. When all of the assigned frequency pairs on a simulcast system are in use, and public safety subscriber radio keys up, the site-controllers will borrow a frequency pair from a neighboring tower site if needed. Since all of the mobile and portable radios follow the control channel, they will automatically switch to the channel assigned for that radio transmission.

73s

Ron

Thank you, kind sir.

 

[Thunderbolt]

Thank you, kind sir.

You're welcome, and Merry Christmas to you and yours!


73s

Ron

 

[OCO]

Merry Christmas, Ron

Thank you for all your work with the database and all the information you pass along!

 

[fireresq2825]

... All of the simulcast systems on the MPSCS, have the ability to use the "Dynamic Sharing Arrangement" (Hereafter: DSA) feature ...For instance, the Washtenaw County Simulcast System is fully loaded and a public safety unit keys up at a major fire scene in Northfield Twp. on one of the Interop talkgroups, but all of the frequency pairs are in use. The site controller will check with all of its neighboring sites, and take a pair that is not in use. In this case one pair from the nearby Northville site so the transmission would be relayed to the other units on the Washtenaw County Simulcast System. If the heavy traffic continues, one of the next transmissions could take place on a frequency pair normally assigned to the Adrian, Howell, or Munith towers thanks to the DSA programming ....

I didn't quote your whole post. I don't know a whole lot about how the sites are programmed, so bear with me if these questions seem silly:

So I'm under the impression that there is a set of frequencies programmed into the Washtenaw (or any other) simulcast system.
When the system goes and borrows a pair from a neighboring site, is the system programming itself with the new pair?
Or are all the neigboring pairs already in there?
I think you kind of know what I'm asking. Are sites software programmable on the fly for whatever freqs they may need?

It doesn't work like that. Not possible. You can't change TX frequencies at a site without optimizing the RF hardware. That being said I think what is being referred to here is there are a few sites that use Dynamic Frequency Blocking "DFB". What that does is allow the sharing of a limited amount of frequencies between sites. This is something set up where that RF hardware is all ready tuned to that specific frequency. Those channels that are DFB are held back by the system unless needed for a voice channel and for obvious reasons will only be assigned at one site at a time. It is nothing that is changed on the fly and you will find those pairs licensed at both sites.

Flat Rock (2502 - Z2 S05) shares one (867.4??) with adjacent Monroe County simulcast (Z2 S18), and Lakeport (2102 - Z2 S02) share at least one with the adjacent Macomb County simulcast (Z2 S??). There may be more, but I don't remember right off. This is something that is not preferred and only done out of a lack of available pairs for licensing. There are several sites that have more RF hardware there than were able to be licensed. With any luck some of that might change with rebanding, but nobody is holding their breath.

If there are no questions class will be in recess...

 

[SCPD]

Chit chat

... All of the simulcast systems on the MPSCS, have the ability to use the "Dynamic Sharing Arrangement" (Hereafter: DSA) feature ...For instance, the Washtenaw County Simulcast System is fully loaded and a public safety unit keys up at a major fire scene in Northfield Twp. on one of the Interop talkgroups, but all of the frequency pairs are in use. The site controller will check with all of its neighboring sites, and take a pair that is not in use. In this case one pair from the nearby Northville site so the transmission would be relayed to the other units on the Washtenaw County Simulcast System. If the heavy traffic continues, one of the next transmissions could take place on a frequency pair normally assigned to the Adrian, Howell, or Munith towers thanks to the DSA programming ....

It doesn't work like that. Not possible. You can't change TX frequencies at a site without optimizing the RF hardware. That being said I think what is being referred to here is there are a few sites that use Dynamic Frequency Blocking "DFB". What that does is allow the sharing of a limited amount of frequencies between sites. This is something set up where that RF hardware is all ready tuned to that specific frequency. Those channels that are DFB are held back by the system unless needed for a voice channel and for obvious reasons will only be assigned at one site at a time. It is nothing that is changed on the fly and you will find those pairs licensed at both sites.

Flat Rock (2502 - Z2 S05) shares one (867.4??) with adjacent Monroe County simulcast (Z2 S18), and Lakeport (2102 - Z2 S02) share at least one with the adjacent Macomb County simulcast (Z2 S??). There may be more, but I don't remember right off. This is something that is not preferred and only done out of a lack of available pairs for licensing. There are several sites that have more RF hardware there than were able to be licensed. With any luck some of that might change with rebanding, but nobody is holding their breath.

If there are no questions class will be in recess...

All right, recess over.
Thanks for the info, FireSquad. When I originally posted the question, I left out, but didn't forget, about the mobiles. So what are the mobiles and portables doing? Are these DFB freqs in the mobiles also? Are there a lot more frequencies programmed into a mobile? (I'm using mobile to mean a mobile or portable here). I know a while back some Allen Park officers went to the UP for something, and they were heard talking back and forth to their base thru the state system. Did that have anything to do with set of DFB freqs being in their mobiles? Or is that an entirely different thing? I realize what you are saying about the base stations need their cans tuned to their freqs, and it would be impractical to have them change freqs on the flly But is it possible for a mobile to be software programmable over the air for either DFB or roaming far from home, like AP did?

 

[rdale]

Portable radios don't need to be licensed for individual frequencies. They transmit wherever the control channel tells them to basically.

Talking across the state is made possible because MPSCS is a statewide system. It has nothing to do with DFB -- it's just roaming.

 

[fireresq2825]

All right, recess over.
Thanks for the info, FireSquad. When I originally posted the question, I left out, but didn't forget, about the mobiles. So what are the mobiles and portables doing? Are these DFB freqs in the mobiles also? Are there a lot more frequencies programmed into a mobile? (I'm using mobile to mean a mobile or portable here). I know a while back some Allen Park officers went to the UP for something, and they were heard talking back and forth to their base thru the state system. Did that have anything to do with set of DFB freqs being in their mobiles? Or is that an entirely different thing? I realize what you are saying about the base stations need their cans tuned to their freqs, and it would be impractical to have them change freqs on the flly But is it possible for a mobile to be software programmable over the air for either DFB or roaming far from home, like AP did?

There is no different programming in the subscriber units since the DFB channels are really just another trunked channel at the site that happens to be a frequency shared with another site. That is strictly at the system level coordinating that frequencies usage.

As far as officers being able to communicate back from out of their area remember, it's just another trunked talkgroup that is usable in that area. The actual RF frequency is unimportant since it's a trunking system. The only frequencies programmed (aside from conventionals) in the subscriber units are a list of control channels to help it find a site faster. It will still eventually find a site even if there are no frequencies in the control channel list since it will band scan if it cant find anything in the list.

 

[rdale]

TG1428 RID 1331740 Heard testing first and discussion about keeping the radio for the weekend, then about 30 minutes later heard "FIRE 4 to central control"

 

[Skud]

Mercy Ambulance Service, covers Barry and Clinton Counties. They are apparently moving their communications onto the MPSCS. I suspect more talkgroups will pop-up in the coming months.

73s

Ron

Lansing mercy out of Barry County is based in Hastings. So you will hear Barry County Central Dispatch call them Hastings Ambulance when they dispatch them. As of now they are still dispatched by the County on 151.355. They do also have 151.280 which I never listened to so going with what I am hearing on TG 13071 which would be the same traffic that was or maybe still is on on 151.280 which is Lansing Mercy's home base(I assume in Lansing, someone in the Lansing area should be hearing this talkgroup) as I hear the unit( Alpha 140 and Alpha 141) checking back at Hastings base, on route to a hospital, or to a call.
I have not hear any other units so far so the Clinton County Units might be on a different TG if they are also moving over as well.

 

[Skud]

Looking at my scanner I have had TG 1515 for Barry County MDOT, but looking in the database I see that 1515 is showing as Van Buren County. Since I only have one scanner right now, if anyone listens to MDOT in the surrounding areas, let me know if you hear MDOT doing snow plowing in the Barry County area and which TG they are on.

 

[Thunderbolt]

Finally, both of the pending licenses for the Wayne County Simulcast System have been approved by the FCC. Hopefully, the system will be online shortly. Here are the licenses:

WQOQ923

WQOQ807

73s

Ron

 

[rdale]

TG1428 RID 1331740 Heard testing first and discussion about keeping the radio for the weekend, then about 30 minutes later heard "FIRE 4 to central control"

1428: Talking about "lottery key" and sending a state car down with it. RID 1331738.

 

[jimsokol]

Looking at my scanner I have had TG 1515 for Barry County MDOT, but looking in the database I see that 1515 is showing as Van Buren County. Since I only have one scanner right now, if anyone listens to MDOT in the surrounding areas, let me know if you hear MDOT doing snow plowing in the Barry County area and which TG they are on.

I am not located in Barry County, but have occasionally in my travels heard several Barry county area references on this talkgroup.

I am more often in areas near Van Buren County and have NOT heard this talkgroup used there

 

[SCPD]

Magic wall

There is no different programming in the subscriber units since the DFB channels are really just another trunked channel at the site that happens to be a frequency shared with another site. That is strictly at the system level coordinating that frequencies usage.

As far as officers being able to communicate back from out of their area remember, it's just another trunked talkgroup that is usable in that area. The actual RF frequency is unimportant since it's a trunking system. The only frequencies programmed (aside from conventionals) in the subscriber units are a list of control channels to help it find a site faster. It will still eventually find a site even if there are no frequencies in the control channel list since it will band scan if it cant find anything in the list.

OK, thanks Fireresq, I didn't quite realize that the mobiles can basically be told to transmit and recieve (within the radio's bandsplit) on any freq the control channel tells it to. I was still stuck on the concept of the radio needed to be programmed for every channel/personality/mode/whatever you want to call them, the radio is going to use.