Question About Site Types on Ohio MARCS-IP

[JethrowJohnson]

So the Washington County site uses cell towers and mobile repeater extenders and I thought that was true for the entire MARCS system, but it seems like some counties aren't simulcast which would mean they don't use cellular towers. So does MARCS use cell towers or is that only the Washington County site?

 

[mtindor]

I think you are misconstruing terms. There are standalone sites (the majority) -- single sites (which Motorola refers to as ASRs) with a set of different frequencies per each site. Then there are simulcast "cells" like Washington County that are made up of multiple physical sites in various locations within the intended coverage area, all of which use the same single set of frequencies and that are time synced to transmit at precisely the same time on the same frequency(s). If you look at the attached picture (forget about the fact that one site is outside of the circle). The "cell" here is a coverage cell. The individual sites within a simulcast cell are located in certain geographic locations to ensure proper coverage within that cell.

So if you are using a scanner and it stops on a particular talkgroup being transmitted on the Washington Co Simulcast, and your scanner shows that the active frequency transmitting that talkgroup is 773.38125, then in reality there are numerous sites within the county transmitting at the same time on 773.38125 to deliver that audio countywide.

The Washington Co simulcast consists of 11 separate sites that are within a single "cell", sharing all of the same frequencies and transmitting all information at the same time on whatever frequencies are active.

It has nothing to do with using cell[ular] towers. Some tower locations within the simulcast cell might actually have cellular company equipment on them, but if they do it's just a coincidence because the system doesn't rely upon the existence of cellular telephone equipment to function.

Designing simulcast networks

Simulcast is an abbreviation for simultaneous broadcast, and in the context of land mobile radio, it means simultaneous transmission from two or more repeater sites on the same radio frequency and with the same modulation.

urgentcomm.com

 

[JethrowJohnson]

I think you are misconstruing terms. There are standalone sites (the majority) -- single sites (which Motorola refers to as ASRs) with a set of different frequencies per each site. Then there are simulcast "cells" like Washington County that are made up of multiple physical sites in various locations within the intended coverage area, all of which use the same single set of frequencies and that are time synced to transmit at precisely the same time on the same frequency(s). If you look at the attached picture (forget about the fact that one site is outside of the circle). The "cell" here is a coverage cell. The individual sites within a simulcast cell are located in certain geographic locations to ensure proper coverage within that cell.

So if you are using a scanner and it stops on a particular talkgroup being transmitted on the Washington Co Simulcast, and your scanner shows that the active frequency transmitting that talkgroup is 773.38125, then in reality there are numerous sites within the county transmitting at the same time on 773.38125 to deliver that audio countywide.

The Washington Co simulcast consists of 11 separate sites that are within a single "cell", sharing all of the same frequencies and transmitting all information at the same time on whatever frequencies are active.

It has nothing to do with using cell[ular] towers. Some tower locations within the simulcast cell might actually have cellular company equipment on them, but if they do it's just a coincidence because the system doesn't rely upon the existence of cellular telephone equipment to function.

Designing simulcast networks

Simulcast is an abbreviation for simultaneous broadcast, and in the context of land mobile radio, it means simultaneous transmission from two or more repeater sites on the same radio frequency and with the same modulation.

urgentcomm.com

I understood the difference between single repeaters and simulcast, although I thought they were both referred to as sites, but I guess the tower is called the site and if there's more than one the sites make up the cell. But the Devola Volunteer Fire Company said that it uses cell towers and so did a Marietta Police officer when I was on a ride-along, so maybe they just meant regular sites and they were calling them cells because our county uses a cell? Because I thought they meant phone towers?

 

[mtindor]

I understood the difference between single repeaters and simulcast, although I thought they were both referred to as sites, but I guess the tower is called the site and if there's more than one the sites make up the cell. But the Devola Volunteer Fire Company said that it uses cell towers and so did a Marietta Police officer when I was on a ride-along, so maybe they just meant regular sites and they were calling them cells because our county uses a cell? Because I thought they meant phone towers?

Even though most MARCS sites are on state-owned towers, that isn't true for all towers. Some of the physical sites within the WashCo simulcast cell certainly could be on towers owned by cellular companies, American Tower, etc, etc. And some are likely owned by the State.

Mike

 

[JethrowJohnson]

Even though most MARCS sites are on state-owned towers, that isn't true for all towers. Some of the physical sites within the WashCo simulcast cell certainly could be on towers owned by cellular companies, American Tower, etc, etc. And some are likely owned by the State.

Mike

Okay. That makes sense, because then they would probably have better coverage that way. Thanks Mike. 🙂

 

[mtindor]

Okay. That makes sense, because then they would probably have better coverage that way. Thanks Mike. 🙂

All but one of the 11 towers is owned by the State of Ohio. The one in Constitution is owned by Gray Media Group, Inc. They could all have cellular equipment on them, or some could, or perhaps none do. I don't know. But none of the towers are owned by cellular companies or third party tower-leasing companies.

WQRI435    1243452    Chesterhill (21555 State Route 550)
WQRI439    1237014    Matamoras (Salem Hall Rd)
WQRI440    1237011    Marietta (Milltown hill Rd)
WQRI441    1237428    Marietta (Eddy Rd)
WQRI442    1245965    Marietta (1143 Cisler Dr)
WQRI443    1239800    Constitution (Doles Knob)
WQRI444    1241343    Coolville (4520 Two Mile Run Rd)
WQRI445    1243464    Beverly (Township Road 511)
WQRI547    1239479    Antioch (47979 Ketzel Hill Rd)
WQRI549    1241345    Coolville (179 Cornes Rd)
WQRJ249    1237423    Lower Salem (Township Road 309)

 

[JethrowJohnson]

All but one of the 11 towers is owned by the State of Ohio. The one in Constitution is owned by Gray Media Group, Inc. They could all have cellular equipment on them, or some could, or perhaps none do. I don't know. But none of the towers are owned by cellular companies or third party tower-leasing companies.

WQRI435    1243452    Chesterhill (21555 State Route 550)
WQRI439    1237014    Matamoras (Salem Hall Rd)
WQRI440    1237011    Marietta (Milltown hill Rd)
WQRI441    1237428    Marietta (Eddy Rd)
WQRI442    1245965    Marietta (1143 Cisler Dr)
WQRI443    1239800    Constitution (Doles Knob)
WQRI444    1241343    Coolville (4520 Two Mile Run Rd)
WQRI445    1243464    Beverly (Township Road 511)
WQRI547    1239479    Antioch (47979 Ketzel Hill Rd)
WQRI549    1241345    Coolville (179 Cornes Rd)
WQRJ249    1237423    Lower Salem (Township Road 309)

Thank you. And a few weeks ago when I submitted the encryption status on Wood County Sheriff's Office, WV you replied and said something about watching for new sites and TGIDs and I've been seeing conversations on here about WV SIRN getting new sites, so is there anything I can help you with there?

 

[mtindor]

Thank you. And a few weeks ago when I submitted the encryption status on Wood County Sheriff's Office, WV you replied and said something about watching for new sites and TGIDs and I've been seeing conversations on here about WV SIRN getting new sites, so is there anything I can help you with there?

Thank you for asking. I'll attempt to PM you via the forums, so that I don't hijack this thread.

Mike

 

[wa8pyr]

I understood the difference between single repeaters and simulcast, although I thought they were both referred to as cites, but I guess the tower is called the site and if there's more than one the sites make up the cell. But the Devola Volunteer Fire Company said that it uses cell towers and so did a Marietta Police officer when I was on a ride-along, so maybe they just meant regular sites and they were calling them cells because our county uses a cell? Because I thought they meant phone towers?

Actually, in trunking system lingo, they're all referred to as "sites." A site can be a single standalone physical site, or it can be a simulcast cell comprised of multiple physical towers (known as subsites), but in either case it's an entity that falls under a single site number in the system.

A site could certainly be sharing space on cellular towers; it's often easier to rent space on an existing tower that's in the right place at $2000-$3000 per month than to build one's own tower at a cost of $1,000,000.

All but one of the 11 towers is owned by the State of Ohio. The one in Constitution is owned by Gray Media Group, Inc.

Many of the state-owned sites in Washington County are repurposed former standalone MARCS sites. The Gray Media location is the WTAP-TV tower.