How does it all
work?
The system was originally planned as a Metro Area regional radio system.
In the years following the September 11th attacks, Federal money was designated
for interoperability and the radio system has been funded for the entire state.
Phase 1 (Complete) — Regional coverage in the seven county Metro area
Phase 2 — Ongoing local coverage in the seven-county Metro area
Phase 3 — Coverage in 23 counties in the Rochester and St. Cloud regions (Funded June 2005)
Phase 4 — Coverage in 13 counties in the Duluth and Brainerd regions
Phase 5 — Coverage in 31 counties in the Mankato, Marshall and Detroit Lakes regions
Phase 6 — Coverage in 11 counties in the Virginia
The Metro Area coverage area (Phase 1) was implemented with three system owners
with the State of Minnesota being the primary administrators. Minneapolis
and Hennepin County funded their own sub-systems to provide capacity for their
use.
#1 MN State backbone & Carver County subsystem.
#2 Hennepin Co subsystem
#3 Minneapolis subsystem
It may be helpful to take a look at the system maps, see System Tower Map.
Because of the geographic size of the MN State system and the Hennepin Co system, they have their areas divided into regions, very similar to how cellular phones operate. Hennepin Co is divided into 2 regions, the MN system has 8 regions. Within each region are between 4 and 6 actual radio towers spread out in different cities. In areas where the system is being built (primarily in the east metro) there are single, standalone sites (WCAL & King Stack). The main system for the Metro area (within the 494/694 belt) is the Mpls-St Paul sites (WPER943).
Each of these regions should have it's own control channel signal. All of the towers within the region should all be simulcasting the same data. The City of Mpls has only one region, but has two towers transmitting (one north, one south).
Now, there are a couple of very important things regarding what radios get broadcasted in what regions. The user's radios constantly sample the various control channel signal strengths (just like a cellular phone).
#1 The system administrators set the profiles for EVERY talkgroup & every radio in use. This profile determines whether the talkgroup can/should be repeated in different regions and different systems (and subsystems). For example: the State Patrol dispatch channels may get repeated across all of the MN State regions/towers. But a car-to-car channel may not. So anywhere in the Metro, regardless of which MN State region you are listening to, you should hear patrol dispatch. However if you're in the SE metro you may not hear a c2c channel for the NW metro because it's not being repeated in that cell.
#2 The various radios on the system are programmed for their preferred system, (MN State, Hennepin Co, or Mpls). They will first try and affiliate within their own system. However, if a State Trooper is inside a building in Downtown Mpls and his radio can only pick up the Mpls system control channel, then his radio will affiliate with Mpls and (assuming his radio profile gives him permission) he can transmit on the Mpls system frequency and it will be re-simulcast back onto the State system. All seamlessly to the user. Also, the trunking controller computer keeps track of the fact that this particular Trooper's radio is affiliated onto Mpls's system - so if any radio traffic gets broadcast on the Trooper's main channel (MN State system) that broadcast will be SIMULCAST onto the Mpls system. This will continue until that Trooper re-affiliates back to the State system. This is why you will sometimes hear State Patrol traffic on the Mpls system, Mpls PD on the Hennepin Co system, etc. This is similar to roaming on cellular phone networks.
There is a fair amount of back-and-forth between the various cells and the various systems. What this also means is that you should not hear Carver County traffic except if you are within range of the Carver county system. The exception would be if a Carver County deputy comes into Mpls, then the Mpls (or Hennepin Co or State MN) system may kick on to simulcast the Carver County radio traffic until the deputy turns off his radio or goes home. This is a fairly big deal and is discussed in the Met Radio board protocols under "scanning" because it has the potential to tie up the smaller cells.
Basically, if you want to hear Mpls - program the Mpls system. If you want Hennepin Co, program the Hennepin Co system. If you want State, program the State system. You will still end up hearing main channels from all agencies spread around though. Find where you are on the system maps to find out what region(s) you are in. Then program in the freq's for that cell to find the control channel.
Technical Background
A regional 800mhz digital radio system has been planned since 1990. Motorola is the primary contractor, with EF Johnson and Harris Microwave picked as sub contractor when the system was first built.
The system is a Motorola 800mhz ASTRO-25 SmartZone digital trunked system. It is fully APCO Project 25 standard compliant (TIA/EIA-102) using 12.5kHz narrow-band and simulcast fully digital radio. All sites have a 9.6kbs data stream.
The Metro Radio board is assigned as Region 22 in the NPSPAC National Public Safety radio plan.
What do I need to listen?
These scanners are 100% compatible with the MN digital system:
Uniden
BC396 (portable)
BC996 (mobile - release date spring 2006)
BC296 (portable - no longer being manufactured, replaced by BC396)
BC796 (mobile - will be replaced by BC996)
Radio Shack
Pro 96 (portable)
Pro 2096 (mobile)
GRE (available online or at some Radio Shacks)
PSR 500 (portable)
PSR 600 (mobile)
The older Uniden BC250d & 750d will properly decode the digital audio - however they will not follow the 9600baud control channel.
The option to encrypt data in the APCO format exists and is currently used for special units (narcotics, detectives, etc). This encrypted is impossible (and illegal) to decode.
Agencies Currently on 800mhz digital system
MnDOT (Metro Area)
Minnesota State Patrol (Metro District)
Minnesota state agencies (BCA, Fire Marshal, PCA, DNR, Capital Security)
Metro Transit (LRT & Buses)
Ambulance Services: HCMC, North, Allina, HealthEast
Hennepin County (incl: Richfield, Edina, Brooklyn Center, Hopkins, Minnetonka, Bloomington, Golden Valley, Saint Louis Park,
Eden Prairie)
Carver County
Anoka County
Minneapolis
University of MN Mpls-St Paul Campus
Mpls-St Paul Airport (MAC)
Rochester & Olmstead County
St Cloud & Stearns County
Saint Paul & Ramsey County
Dakota County
Agencies in planning stages
Scott County (switching in late 2008)
Washington County (likely in 2009)
Other Links
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