PSR 500/600 setup for large multi-site P25 system

[BenFranske]

I've recently upgraded from a Pro-2096 to a PSR-600 for my main scanner and I'm interested in having a discussion here with other PSR-500/600 users about programming organization specifically as it relates to large, multi-site P25 systems. I did post something about this in the Minnesota forum, but there are very few other PSR-500/600 users so far in Minnesota so we're all sort of stumbling in the dark. Hopefully someone from another part of the country has some insight on this.

In Minnesota we have a statewide P25 digital trunking system which is comprised of several sub-systems some of which overlap geographically. In one example a state trooper from one part of the state may drive to another part of the state and pull their talkgroup with them meaning that in theory almost any of the talkgroups could be heard on any of the systems though there are some exceptions where certain users are not allowed to affiliate with certain sub-systems.

The tricky part about this is in the Minneapolis/St. Paul area which is covered by multiple sub-systems (Minneapolis, St. Paul, Hennepin County East, Ramsey County and MN State Metro Area). Users on these sub-systems frequently affiliate with a system other than their home system (for example a state patrol officer driving in Minneapolis could be on the Minneapolis, Hennepin County East or MN State Metro Area system) and would pull their talkgroup with them.

Thus, my question is should I treat the entire statewide system as one large system (eg. one TSYS object with lots of control channel frequencies) or divide it into sub-systems (separate TSYS objects for Hennepin East, Minneapolis, Ramsey, State, etc.)? What are the advantages and disadvantages?

For the time being I'm treating it as one large system but obviously I can't put all the control channels in (just the ones I'm most likely to hear from my location).

Also, any thoughts so far on MultiSiteMode (Off/Roam/Stationary)? I'm assuming this also might be impacted by whether you treat it as one system or as several.

I can see advantages in treating it as a single system (when units roam onto another system and pull the talkgroup you won't miss them if you have a stronger signal from that system, no need to duplicate interop talkgroups, possibly faster scanning).

On the other hand I can see advantages in treating it as multiple systems because I think if you treat it as one system depending on the MultiSiteMode you could potentially lock on to a single control channel (eg. the Minneapolis system) and miss traffic on another system (like HennepinE).

 

[fmon]

Thus, my question is should I treat the entire statewide system as one large system (eg. one TSYS object with lots of control channel frequencies) or divide it into sub-systems (separate TSYS objects for Hennepin East, Minneapolis, Ramsey, State, etc.)? What are the advantages and disadvantages?

I downloaded your file from the MN forum and would use the file as you have it. Turn the Scanlist on/off as needed.

Also, any thoughts so far on MultiSiteMode (Off/Roam/Stationary)? I'm assuming this also might be impacted by whether you treat it as one system or as several.

My Virginia P25 is set to ROAM, however, while setting at this PC, uses the nearest control even though sampling through the others. If traveling through the area, it will still use mostly the closest control.

 

[BenFranske]

Thanks for your reply. I thought the GRE documentation was a bit unclear on how the MultiSite operation works. My concern is that the scanner will lock on to one control frequency and not check all of the control frequencies for the talkgroups. Because not all the talkgroups are active on all of the control channels at any given time I imagine that it could be the case that the scanner might sample all of the control channels and then select only ONE to check for talkgroup activity. I don't want this to happen because I want to hear (for instance) activity on both the Minneapolis and Hennepin County East subsystems. If the scanner is only "listening" to the Hennepin County East control channel it would only pick up Minneapolis traffic when a user from that system happened to affiliate with the Hennepin County East system.

On the other hand I don't want to have to duplicate my talkgroup list four times over so all of the talkgroups are monitored on all four sub-systems the scanner might hear.

 

[fmon]

If you keep STAT selected the normal control used may be the closest tower and affiliation will occur if in range of the tower. With a single TSYS this can't be helped short of TG lockout when it occurs. Remember, soft LO resets with scanner turnoff.

 

[mikey60]

Thanks for your reply. I thought the GRE documentation was a bit unclear on how the MultiSite operation works. My concern is that the scanner will lock on to one control frequency and not check all of the control frequencies for the talkgroups. Because not all the talkgroups are active on all of the control channels at any given time I imagine that it could be the case that the scanner might sample all of the control channels and then select only ONE to check for talkgroup activity. I don't want this to happen because I want to hear (for instance) activity on both the Minneapolis and Hennepin County East subsystems. If the scanner is only "listening" to the Hennepin County East control channel it would only pick up Minneapolis traffic when a user from that system happened to affiliate with the Hennepin County East system.

To get what you're looking for, put the scanner in STAT mode. This will cause the scanner to check each control channel it finds. There are two modifiers to the STAT mode that change how those control channels are checked.

If the Check All option is turned on, all control channels that can be heard will be checked every time the TSYS object's talkgroups come up in the scanning cycle. Depending on how many active control channels are in the TSYS, it may take a second or two to get through the TSYS object.

If the Check all option is turned off, one control channel will be checked on each pass through the TSYS object. This will start with the first control channel the radio can hear. On the next pass, the next control channel in the list will be checked, and so on until all have been checked at which point, the first one will be checked again.

Mike

 

[BenFranske]

That's the explanation I was hoping to find in the manual! I think that STAT with Check All enabled is exactly what I'm looking for.

Out of curiosity...could you or someone else give a similar description of the "Off" and "Roam" modes with and without "Check All" enabled?

 

[RKG]

That's the explanation I was hoping to find in the manual! I think that STAT with Check All enabled is exactly what I'm looking for.

Out of curiosity...could you or someone else give a similar description of the "Off" and "Roam" modes with and without "Check All" enabled?

I believe the following is approximately correct:

"Off" will stop on the first control channel with usable data and stay there so long as it is usable. The "Check All" option is not applicable (or visible) in this mode.

"Roam" will sample all control channels, pick the one with the strongest signal, and stay there until the signal falls below the level set in the "low threshhold." The "Check All" option is not applicable (or visible) in this mode.

Stat with "Check All" is functionally the same as programming each "zone" in the system as a separate TSYS and then scanning all of the TSYSs sequentially. I'm not sure what STAT is with "Check All" not checked.

ROAM attempts to simulate Motorola SmartZone functionality. However: (a) it is far cruder in its criteria for searching for a better control channel, (b) it apparently does not make use of the data stream's statement of the control channels for adjacent zones, and (c) it does not mask a control channel found to have SmartNet data for SysID. This last is an issue if one of your target system's control channels is also used by some other system that is within your listening range.

Bear in mind that, however configured, your radio can listen to only one control channel at a time. If a given Talkgroup is not active on the zone associated with that control channel at that time, you won't hear any traffic on that Talkgroup. This is a limitation inherent in the SmartZone construct whenever zones are grossly overlapping in geographic coverage. This limitation is mitigated (somewhat) if you can affiliate and it is exacerbated (somewhat) if you cannot.

 

[thewenk]

Here is an additional explanation from GRE:
http://www.greamerica.com/support/index.php?_m=knowledgebase&_a=viewarticle&kbarticleid=9

Dave

 

[ocguard]

I'm using the Multisite Roam setting for York County, PA's multi-site 500mhz P25 system. The quality of the scanner's ability to effectively roam is, in many cases, equal or superior to my system portable performing the same task.

The only problem is that, in a Harris P25 system, ANY system frequency can be used as the control channel. I have noticed no specific pattern as to if any frequency is used as the CC more often than another. So that's 3 sites with 10 freqs each and 1 with 14 freqs. This, obviously, far exceeds the scanner's capacity for control channels for one TSYS. Any ideas on how to overcome this? I currently have 3 TSYS's. One for each combination of roaming I'm likely to encounter. I have to manually enable the correct system as I move north, south, or west from the center of the county.

 

[tglendye]

...
If the Check All option is turned on, all control channels that can be heard will be checked every time the TSYS object's talkgroups come up in the scanning cycle...

Sorry to ask a stupid question, but I am having problems locating the "check all" option, at this moment. I'd like to know how I have mine set up.

Thanks,
Todd

 

[W6KRU]

Sorry to ask a stupid question, but I am having problems locating the "check all" option, at this moment. I'd like to know how I have mine set up.

Thanks,
Todd

You have to set multi-site to Stat.

 

[tglendye]

Thanks. I knew that before, but couldn't remember. I have mine set to Roam at this time.

Todd

 

[MaximumVerbosity]

I'm in the Twin Cities (NW suburb) as well with a PSR-500.

I'm still experimenting with the best way to set it up. I currently have a TSYS for the metro sites and have TG's for HCSO South, North, East, EMS, MNSP, and other Henn Co cities (Richfield, Bloomington, GV, SLP, Edina, etc). Also had MPD/MFD talkgroups, but that's hit or miss. MPD ch 2 gets into the tower near me, but not 1 or 3, unless a unit is out west somewhere. And it didn't seem to switch control channels to the other site, so I'd miss activity on MPD 1 & 3.

Then decided to put MPD's TG's into their own TSYS with just their site downtown (1-009). Even though the signal is a little weaker, but now I get all of the TG's reliably.

Had the scanner for the metro TG's in roam mode, but it worked mediocre. Then left it in stat, but seemed like I'd still miss a bunch. On the way home today, was bored, so turned that off. Now it seems to work much better, and the audio breaks up less during transmissions.

Been thinking that I should redo some of these so for HCSO S, E & N, it uses the tower near me. For MNSP… oh who knows. They go all over the place, so would miss stuff. Maybe three TSYS's (nearby tower, Mpls tower, and a TSYS for the rest of the metro). Of course, that makes searching for wildcard TG's impractical, unless just searching in the TSYS that covers the whole metro. However, for me, I don't scan much for new TG's, so not a big deal.