Listening to Statewide Systems…Statewide

[msanders1989]

New to scanning and just bought a BCD536HP. I found my local sheriffs office and saved it in my favorites. My understanding is they are on the Louisiana statewide system. If the frequency works statewide, why can’t I listen to them anywhere in the state?

 

[Whiskey3JMC]

Welcome to the RR forums. What specific sheriff's office are you inquiring about? Are you sure they aren't encrypted? Are Law Dispatch, Law Talk & Law Tac service types turned on? Lastly if you're listening on a "simulcast" group of sites you may encounter a phenominon known as simulcast distortion depending on your location relative to two or more simulcasting towers. Can you pick up other talkgroups on the LWIN reliably? if not you'd probably be better off monitoring via an SDS100 or SDS200

 

[msanders1989]

Welcome to the RR forums. What specific sheriff's office are you inquiring about? Are you sure they aren't encrypted? Are Law Dispatch, Law Talk & Law Tac service types turned on?

Thanks. They are not encrypted. I can hear them just fine as long as I would in a couple of miles of the town. Vernon Parish, Louisiana. Under the Louisiana Wireless Information Network. All service types are turned on.

 

[mmckenna]

New to scanning and just bought a BCD536HP. I found my local sheriffs office and saved it in my favorites. My understanding is they are on the Louisiana statewide system. If the frequency works statewide, why can’t I listen to them anywhere in the state?

It has to do with the way these large trunked systems work.
The trunked system is made up of a lot of radio sites, those are needed to get the almost "statewide" coverage. Each trunking site will have many frequencies assigned to it.
There isn't enough frequencies at each site to carry traffic from every single talk group on the system. Just not enough resources and actually no need to do that.
The way the systems work is that the individual radios will "affiliate" with a specific radio site. The radio will tell the system which talk group it wants to listen to. The trunked system controller will route the right talk groups to that site so the radio can hear the traffic.
It's not uncommon to assign talk groups to specific sites only, and not let them be used at every site on the system.
So, what this does is makes the best use of the limited resources (frequencies) at each site. Only the radio traffic that needs to be present on that site is sent there. If no officers/radios from that agency are affiliated at that site, there's no point in routing radio traffic there.
If one of their radios roams onto that site the trunk system controller will see that and route traffic there.
That frees up those limited resources for other users.

Since your scanner cannot affiliate with the trunked radio sites, the trunked system will not route that talk group there.

 

[msanders1989]

It has to do with the way these large trunked systems work.
The trunked system is made up of a lot of radio sites, those are needed to get the almost "statewide" coverage. Each trunking site will have many frequencies assigned to it.
There isn't enough frequencies at each site to carry traffic from every single talk group on the system. Just not enough resources and actually no need to do that.
The way the systems work is that the individual radios will "affiliate" with a specific radio site. The radio will tell the system which talk group it wants to listen to. The trunked system controller will route the right talk groups to that site so the radio can hear the traffic.
It's not uncommon to assign talk groups to specific sites only, and not let them be used at every site on the system.
So, what this does is makes the best use of the limited resources (frequencies) at each site. Only the radio traffic that needs to be present on that site is sent there. If no officers/radios from that agency are affiliated at that site, there's no point in routing radio traffic there.
If one of their radios roams onto that site the trunk system controller will see that and route traffic there.
That frees up those limited resources for other users.

Since your scanner cannot affiliate with the trunked radio sites, the trunked system will not route that talk group there.

Thank you so much. This makes perfect sense.

 

[mmckenna]

Thank you so much. This makes perfect sense.

No problem. It's a good question.

Welcome to the hobby, stick around, pull up a chair, crack open a cold one.

 

[slayer816]

Hello and welcome.

Your radio will do fine in your area. NOLA, St Tammany, and BR have simulcast sites which MAY cause some distortion as stated above. The "statewide" part is for agency radio users who can turn on their radio and it work "statewide" as all sites are linked. Hopefully in the past few weeks you have learned some about your radio and the LWIN system with the good info provided above. If you start hearing things that do not match the database, please submit confirmed changes!

 

[jim202]

The down side to the LWIN system is some of the tower sites only have 2 voice channels. This means it won't take much to fill that tower up and even prevent local users from being able to use it.

I will give you an example of how easy it is to fill up local tower voice channels. Saint Tammany Parish has 8 tower locations with 8 available voice channels set up in a simulcast system. But Saint Tammany Parish is a bedroom community for many people that work outside of the Parish.

Like you have a pile of people that work in New Orleans. Like the fire, police, DPW, plus others. If they each take home a portable and leave it on, they just sucked up at least 3 voice channels if there just happens to be chatter on the talkgroup they are listening to. Now add the State Police, DOT, Corrections workers from multiple locations and you could possibly have another 3 to 5 voice channels sucked up at some point in time.

With the above information, now add a major weather front passing through. It doesn't take long before the normal Saint Tammany Parish LWIN users no longer have the ability to use the trunking system. This is why the Parish Fire Department users have maintained their older VHF radio systems. It allows them to still function when the people outside the Parish clog up the limited radio resources on the LWIN system.

Don't forget the local police and fire department workers in Saint Tammany are going to keep their radios on while at home.

I can understand these people that work outside the Parish want to keep an ear on what is going on at work, but they also need to understand they are causing the local users not to have radio service when an emergency comes up.