Central New York Interoperable Communications Consortium (CNYICC) Simulcasting

[w2vgp]

Please forgive me if this has been discussed in another thread and point me to it. I am trying to understand the simulcasting within the CNYICC. I have an SDS100 and have been listening to Law/Fire/EMS in Oswego, Onondaga, and Cauyga Counties (I live in Oswego County). When home in Oswego County and listening from an Oswego County tower, I am hearing all the dispatch and local fire etc. From the surrounding counties I am primarily hearing just the dispatch and not the more localized talkgroups. When I travel into Onondaga County, listening from an Onondaga County tower, I then begin to hear the localized talkgroups within Onondaga County. How does the simulcasting work county to county? Are just the main dispatch talkgroups simulcast outside of each county and you need to be listening to a county tower for talkgroups within the county you are in? I am trying to come up to speed on how the P25 systems work since getting a BDC996P2 last Christmas and an SDS100 a week ago. I love listening to everything and then just specific talkgroups when specific events are occurring.

 

[flagship2023]

With large systems like that areas are broken into sites/cells. Usually each individual radio connects to a tower in the cell and affiliates (basically says I’m here and on talk group X). Then talkgroup X is broadcast to every tower within that simulcast site. The talkgroup is only broadcast if a radio is listening for it so you usually will only hear talk groups on the sites for the geographical areas they are used even though they can be used wherever the system has coverage.

A radio from Onondaga may connect to the Oswego site so you might hear Onondaga on Oswego but usually it will connect to the Onondaga site.

 

[sallen07]

I am trying to understand the simulcasting within the CNYICC.

@flagship2023 gives a good explanation of why you only hear "local" traffic in the county you are in: there needs to be a radio on that talk group affiliated with a particular cell in order for that TG to be active in that cell. That rule also applies for the dispatch traffic but the affiliated radio could be at the dispatch center. It's also possible for the system admin to "nail up" a talkgroup so it's *always* active on a cell, whether there is a radio affiliated or not.

But I'm not certain that "simulcast" means what you think it means, at least as the term is commonly used on RR. Simulcast is when there are multiple towers (within one "site") that all transmit the same information on the same frequencies at the same time. For example, Oswego county has a single simulcast site with 15 towers throughout the county, if I counted right on the map.

Central New York Interoperable Communications Consortium (CNYICC) Site: Oswego Simulcast

Central New York Interoperable Communications Consortium (CNYICC) Site: Oswego Simulcast Details

www.radioreference.com

So when you hear talk of "simulcast systems" or "simulcast distortion" *that* is what is being discussed, not the carrying of traffic for one county on another county's site or sites.

Hopefully that helps.

 

[studgeman]

To add on to others...

A "Site" is best described as a transmitting site or sites on the same frequency with the same system address. This can include upwards of 20+ towers to create one "site" This is how the counties create seamless coverage with RF simulcast. By system address that means the WACN, SysID RFSS and Site numbers all together. See any P25 trunked system in the DB.

A system can be configured in many different ways with varying permissions, so there is no one rule here. Radios have permissions, talkgroups have permissions. Not every radio and talkgroup is required to be allowed at every site. Talkgroups that are allowed at multiple sites can be pushed full time to those sites, (Onondaga Fire Control) or the talkgroup can follow an authorized radio as it travels from one site to the next. Some talkgoups may not be allowed at other sites, the user would receive an out of coverage bonk/access denied when roaming.

For CNYICC several main talkgroups are pushed full time to other counties. That is what you are hearing. Onondaga Fire and Onondaga EMS are pushed almost everywhere. Certain "local" talkgoups will only become active on a neighboring system if there is a radio affiliated to that talkgoup. Most "local" talkgroups are only allowed on their "home" site.

 

[w2vgp]

Thanks for the replies on what I'm hearing across the various sites. I've also noticed that when listening to the Onondaga County site I hear the Madison County Fire Dispatch where I do not hear that from the Oswego County sites. I guess if I wanted to hear more from Onondaga County from my home I'll need to have an outdoor antenna. Its only a few miles south to where I begin to pick up the Onondaga County site from my handheld scanner, so an outdoor antenna (especially a directional antenna) should work. I'm quickly coming up to speed on the trunked systems since it's been years since I've last had a scanner and those were the former conventional analog scanners.