Analog OPP question

Status
Not open for further replies.

Wretched

Member
Joined
Aug 26, 2008
Messages
52
Location
Perth County, Ontario
Hi guys, newb here, scanners still on the way....

I just bought a BCT-8 before looking around here much, and I see that almost everything OPP is digital now.

I was just wondering if there is still much analog to listen to, or not really?

For e.g are vehicle repeaters analog still, what about the Sim11 and other channels listed under conventional frequencies and such? where can I expect to find the most action that I can actually listen to (freq's), and what kind of communications would it be? I'm never more then 20 miles from Listowel or Sebringville OPP stations if that matters. I'm mostly interested in knowing if I see a cop driving around my area will I be able to hear anything of his communications? What about heli's/planes?

Thanks!
 
Last edited:

sirsmiley

Member
Joined
Aug 12, 2005
Messages
263
Location
Ontario
i think all the cars also transmit in analog but its short distance...you have to be decently close....ive picked them up on numerous occasions and id say i can even pick them up 5-10 km away on analog..but if theyre down the highway or something you wont pick it up, not like the fleet towers on digital...

also the provincial common one is used quite a bit by ones like west grey etc to talk to opp or other municipalities to talk to opp
 

jellotor

Member
Joined
Jan 6, 2004
Messages
1,077
Location
Hamilton, ON
What you are talking about is called a vehicular repeater. When an OPP officer leaves his vehicle and goes on foot, his UHF portable radio communicates with the VR in his car, which repeats his conversation across the Fleetnet talkgroup and the conversations on the talkgroup back to his portable.

Simplified explanation, but I'm not a genius.
 

Jammin_Jay

Member
Joined
Jul 13, 2004
Messages
718
When there are more then 1 OPP car in an area on a call, sometimes they have 3 or 4 vehicle repeaters all on at the same time, and the comm center tells the officers to turn of their repeaters and have only have 1 in use. This happens quite a bit when listening to a call. I believe, even when an opp officer talks on their portable. The ID that comes up on the dispatch screen, its the ID of the repeater in use, not the portable, but someone can correct me if i am wrong.
 

Muxlow

Super Secret
Joined
Aug 16, 2005
Messages
1,622
Location
Middlesex County
Most of the cars now have "smart repeaters" so when you get a few cars all around each other and they all use their portables, the repeaters will auto shut off or change modes, less work for the officer to do. Not all of them have these.. but i think most do.
 

Forts

Mentor
Database Admin
Joined
Dec 19, 2002
Messages
6,687
Location
Ontario, Canada
Most of the cars now have "smart repeaters" so when you get a few cars all around each other and they all use their portables, the repeaters will auto shut off or change modes, less work for the officer to do. Not all of them have these.. but i think most do.

That's the way it's supposed to work, but most of the time it doesn't seem to. I was listening to them trying to setup with the aircraft a few weeks back and they had nothing but repeater problems. One issue was simply from patrol cars in the area, not involved with the intercept, but had their repeaters on. They eventually got it sorted out, but it took a while.
 

moosexing00

Member
Joined
Nov 20, 2005
Messages
21
Most of the cars now have "smart repeaters" so when you get a few cars all around each other and they all use their portables, the repeaters will auto shut off or change modes, less work for the officer to do. Not all of them have these.. but i think most do.

Not the case....the portable being used "searches" out the cruiser radio with the "lowest serial number" within range and uses that vehicle...regardless of which vehicle the officer is operating
 

mikewazowski

Forums Manager/Global DB Admin
Staff member
Forums Manager
Joined
Jun 26, 2001
Messages
13,447
Location
Oot and Aboot
Not the case....the portable being used "searches" out the cruiser radio with the "lowest serial number" within range and uses that vehicle...regardless of which vehicle the officer is operating

No, the cruiser radio and the vehicular repeater are not linked to such an extent that they pass any information along such as serial numbers. The VR's aren't even that smart to do any sort of handshaking with the portable.

The old PAC-RT's listened for the startup beep of another repeater in range and would shut themselves down. That way there was only one PAC-RT on at a time. They even had a routine that would listen for a non-repeated transmission and then reenable themselves just in case the repeater car drove away. It wasn't a bad system considering the technology in use at the time.

It's probably a good bet the VR's are using something similar.
 

moosexing00

Member
Joined
Nov 20, 2005
Messages
21
No, the cruiser radio and the vehicular repeater are not linked to such an extent that they pass any information along such as serial numbers. The VR's aren't even that smart to do any sort of handshaking with the portable.

The old PAC-RT's listened for the startup beep of another repeater in range and would shut themselves down. That way there was only one PAC-RT on at a time. They even had a routine that would listen for a non-repeated transmission and then reenable themselves just in case the repeater car drove away. It wasn't a bad system considering the technology in use at the time.

It's probably a good bet the VR's are using something similar.

Unfortunately that is how they work. Hit the priority on any portable, it goes to the lowest serial number radio installed in a car first, then the next, next and so on. The VR do NOT shut themselves down, it has to be done manually inside a car.
 

mikewazowski

Forums Manager/Global DB Admin
Staff member
Forums Manager
Joined
Jun 26, 2001
Messages
13,447
Location
Oot and Aboot
moosexing00;888592 The VR do NOT shut themselves down said:
I guess the last bullet regarding a contention algorithm on Page 4 of this document is incorrect?

http://www.ambulance-transition.com/pdf_documents/gmcp_status_features_design_oct01.pdf

Also check out Page 36 of this document:

http://www.ambulance-transition.com/pdf_documents/gmc_project_overview_presentation.pdf

BTW, the priority button on a portable is for signalling emergencies. It's not for finding the VR with the lowest serial number.

I just find it hard to believe what you're saying is technologically possible.

If you're saying that the portable finds the mobile radio with the lowest serial number, does it somehow direct all communications only to that VR and all the other VR's know not to transmit? They must if you say that they can't be shut off remotely.

And how do you keep all the VR's from transmitting the car radio's serial number at the same time? When the portable queries the repeaters for the lowest serial number, they would all respond since they don't know what other cars are onscene.

And if the VR's are capable of sending data to the Tait handhelds regarding serial number, why can't they send back the ID of the portable transmitting?

IIRC, back when FutureCom started working with Bell Mobility Radio, the only way they could come up with shutting the VR's on and off from the mobile radio was to look at the SB9600 bus and read the button presses. I don't think any other information was passed to the VR. I also don't believe that any information is passed between the portable and the VR.

Perhaps one of the other guys with more experience with the actual workings of the VR's will chime in.
 

moosexing00

Member
Joined
Nov 20, 2005
Messages
21
EMS is far different than OPP.

I know what the priority vs regular talking on a portable is all about.

Maybe something is wrong with every single car we have ever received with the radio system.

I know when you priority it goes off which ever car's radio that has the lowest serial number (this is told to us by Kelcom) If we turn on every mobile radio in the parking lot, priority it goes to dispatch by that same car. Turn the car off and next car will be picked every time. Turn the 2nd car off and it will then again grab one car.

When you key the portable with multiple units around, again it will transmit through the lowest serial number mobile, plus the surrounding cars....however......if I am identified as " 6E099" and I transmit and another officer 6E097 there with VR on, his unit happens to be lower serial number.....I will then transmit and show up to dispatch as "6E097", rather than my call sign "6E099". This can happen even sitting in my car and using my portable.

Once one unit starts transmitting to the dispatch no one else can transmit, but the other units do hear the transmission.

this is the extent of my knowledge of how our radios work....but there is definetely no turn off capabilities other than manual for a VR, no automatic turn offs by our dispatch of the VR. Once done transmitting the "VR" symbol still is showing on every car, even when transmitting the "VR" symbol is showing.
 

mikewazowski

Forums Manager/Global DB Admin
Staff member
Forums Manager
Joined
Jun 26, 2001
Messages
13,447
Location
Oot and Aboot
EMS is far different than OPP.

Actually no. Except for the fact that MOH is using MCS2000's instead of the Astro Spectra, the system's are the same. Both of you are using the same vehicular repeater from Futurecom.

I know when you priority it goes off which ever car's radio that has the lowest serial number (this is told to us by Kelcom)

There's your problem. Kelcom has misinformed you.

The VR's do have a contention algorithm built in but it's not based on the mobile's serial number.

Even though your Astro Spectra might show that your VR is on, it might have inhibited it's transmit based on other VR's showing up at the scene. Each VR will wait to see if the portable is being repeated by another VR. If nothing is heard, it will repeat the transmission. If the portable is being repeated by another VR, then it will remain silent.

If you think about what Kelcom has told you, it doesn't make sense. How do the cars know which serial number is the lowest? How do they know what other cars are on the scene and what their serial numbers are? How do they determine that the car with the lowest serial number has driven away and they are now the lowest serial number?

Keep in mind that the VR is a totally separate device from the mobile radio. The VR looks for your VR status button presses on the SB9600 bus and acts accordingly (VR mobile, VR local, VR system). The VR does not communicate back to the mobile radio at all and it doesn't look for anything other then those 3 status button presses. I had heard at one time Futurecom was just looking for the VR led's status on the DEK box to determine whether or not to activate the VR.
 

Wretched

Member
Joined
Aug 26, 2008
Messages
52
Location
Perth County, Ontario
Are the VR's always on, or does the officer turn them on and off when entering/exiting their vehicle? I've heard fleetnet traffic on VR1 that slowly comes in clear, then disapates, as if the VR is on while the vehicle is just driving through town, obviously the officer is not out of the car while it's moving (I hope), but also have been past cruisers that have given no traffic on the VR channels (maybe no action on fleetnet while I was in proximity, or maybe turned off???).
 

mikewazowski

Forums Manager/Global DB Admin
Staff member
Forums Manager
Joined
Jun 26, 2001
Messages
13,447
Location
Oot and Aboot
Are the VR's always on, or does the officer turn them on and off when entering/exiting their vehicle?

The officers turn them on and off. If you've got Trunk88 or some other program which watches the control channel data, you can see the VR's being turned on and off.
 

vabiro

Member
Premium Subscriber
Joined
Jan 6, 2004
Messages
271
Location
Toronto, Ontario
How do the cars know which serial number is the lowest? How do they know what other cars are on the scene and what their serial numbers are? How do they determine that the car with the lowest serial number has driven away and they are now the lowest serial number?

Mike_Oxlong said:
The officers turn them on and off. If you've got Trunk88 or some other program which watches the control channel data, you can see the VR's being turned on and off.

I haven't a clue about the voting or functioning of this system but these two statements got me thinking: Is this a possible answer? The VR is monitoring the control channel data for adjacent VR, and this is where the serial number info is being obtained?

Edit: Another variable, to determine the proximity of the VRs could be the RSSI (http://en.wikipedia.org/wiki/RSSI), which would help identify the closest VR. This might give some indication of the dynamic nature of a scene by identifying the RSSI value for traffic as the cars register on the control channel. This would be similar to the method used by cell sites to identify the phones that are within coverage.

Victor
 
Last edited:

mikewazowski

Forums Manager/Global DB Admin
Staff member
Forums Manager
Joined
Jun 26, 2001
Messages
13,447
Location
Oot and Aboot
The VR is monitoring the control channel data for adjacent VR, and this is where the serial number info is being obtained?

The VR's are pretty dumb units. They watch for the appropriate button press to indicate what mode they should be in and they monitor the VR frequency for other VR's.
 

Wretched

Member
Joined
Aug 26, 2008
Messages
52
Location
Perth County, Ontario
I'm gonna re-phrase my question.... does the officer turn on his VR before getting out of his vehicle for a traffic stop, etc, or does he leave it on constantly, unless he is off duty or such. As I said, I've heard VR's operational from moving vehicles, is this the norm, or just a mistake on the officers part by not turning it off after the last time he was away from his vehicle?
 
Status
Not open for further replies.
Top