Virginia State Police DVRS

[ka3jjz]

Moved from the wiki - please don't post discussion questions there, per policy...
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From N4JRI;

A few things to ponder:

1 - VR-11 and VR-42 are not operating digital AFAIK. They are repeating conventional freqs and doing so in analog mode using a DCS code of 023. They would also be known as VR-11A and VR-42A in all likelihood.
2 - As anyone confirmed VR-33 as EPU?
3 - Lots of NAC's of 07B and it may be right, but who's ever heard them in action? Are we filling in blanks with guesses here?

73 Mike

 

[c5corvette]

I am surprised no one noticed this or mentioned it as things to ponder...

Why is there no channel 46 ? ;-)

 

[Ghstwolf62]

That's a lot of the reason I didn't submit things to the database at first but put it up here. With so much changing so rapidly the information wasn't certain IMO. I put it up here so others could take a look at what I "Thought" I'd found and either confirm it or not. Look what happened with what I thought was a DVRS freq.

Plus a lot of the site info is changing day to day and no idea how it will pan out in the end. One day 161.850 is the control channel and the next 161.9375 is so which should be submitted? Plus I've noticed at least one freq being assigned to a new site.

IMO it's all well and good to submit confirmed information into the database as quickly as it can be confirmed but to do it at this point is liable to do nothing more than make DB admins a lot of extra work changing stuff before it's all said and done.

Putting it up here and letting others vet it for authenticity and once stabilized and confirmed it can then be consolidated and placed into the DB. Saves headaches that way. Scared now to send in corrections because the next day it might be different yet again which has already happened.

Also have to agree with OP who said DVRS should be under STARS not separate agency listing. These are extenders to VSP STARS system afterall.

 

[c5corvette]

Also have to agree with OP who said DVRS should be under STARS not separate agency listing. These are extenders to VSP STARS system afterall.

Actually, I would disagree with exactly what you say, but I don't disagree that it might be listed wrong.

From a RR db standpoint STARS is a trunked system that lists trunked site frequencies in the RR db. STARS only refers to the trunked sites in the RR db. To further that argument the commonwealth of virginia department of information technology interop website even states that the "STARS system is a multi-site P25 VHF (150/160 MHz) Trunked Integrated Voice and Data (IV&D) communication system." If you follow that logic, I would even go so far as to remove the 800 portable repeater channels that are listed in the RR db as a STARS site, but I am not the db admin!

IMHO, the 800MHz repeater and the 700MHz DVRS channles are simply another system(s) that is part of the equipment that can interconnect users to STARS. There are other links to STARS too like COMLINK and RIOS. DVRS is just another way to connect.

The real issue I see here is that both STARS and the DVRS are not unique to VSP, but they have it listed as if its owned by VSP. Its a statewide system and there are multiple state agencies that use the system! I dont think we as RR.com users can change the way the admins decide to classify things. The admins are likely not from Virginia and don't understand anything more than the info they are given from whoever is submitting it.

Also, I think its okay to be submitting things that may change - we don't know they will change and when its submitted its accurate and may be usefull to the RR.com user. If the admins feel this is a burden, maybe RR.com will find new admins who want to do this thankless job. That said, I do disagree with submitting assumptions and unfortunately at this point I think someone has submitted assumptions!

 

[n4jri]

I can confirm this much:

765.40625 $07B- repeats Div.1 (Zone 1) VSP
765.16875 $07B- repeats Div.5 (Zone 5) VSP
764.45625 d023 - repeats legacy Ch-1's
765.71875 d023 - repeats legacy Ch-2's
764.20625 $07B - repeats DGIF TG's at least in their regions 1 & 5.

764.15625 & 764.40625 appear to have changed usage with Phase III. In Div.1, they repeated TG's 0001 and 0003 respectively. The latter was also heard in Div.5.

73/Allen (N4JRI)

 

[c5corvette]

764.15625 & 764.40625 appear to have changed usage with Phase III. In Div.1, they repeated TG's 0001 and 0003 respectively. The latter was also heard in Div.5.

73/Allen (N4JRI)

I can confirm this much...

The DVRS channels scheme that someone posted is used for more than just DVRS and is way more complicated than one table in this db will ever detail. For example with VSP (not withstanding any discussions of the two channel pairs used with the conventional stuff) each of the 7 divisions uses a freq pair for DVRS communications and uses the same for simplex or direct. Whereas another agency may have only one VR channel pair that does DVRS for them, but they may use a totally different DVRS pair in a simplex mode as a talk around channel or some other tactical communications channel - I have seen this set up in use for another Virginia agency (I will not say which one) so it is not speculation or an assumption.

As far as Allen's post... when not in direct mode if the user doesn't match the VR channel setting on the portable with the same exact VR channel setting on the mobile radio, with someone standing close enough to the car with thier handheld the DVRS can think its hearing the right thing but its not really on freq and can cause the wrong car channels to be repeated out over the wrong frequencies thus the confusion you might have heard on 764.15625 & 764.40625 respectively. (If indeed all the freqs are using the same NAC code, this problem described above could possibly be eliminated by using different nac codes for each pair.)

Speaking of someone standing close enough to the car... it is also a fact that if you are too close to your car sometimes the DVRS won't hear the portable at all like there is a dead zone.

If you need a primer about how the DVRS works or basic functions, see the other related post I responded to in the Virginia forums.

 

[Samuel]

Maybe I am missing something obvious but I was hoping someone could fill me in on why they need 40 something different frequency combinations for the DVRS? I could see a couple of different combinations for special events but they are short range so why does each divison need a different assignment?

 

[freqhopping]

I don't know about being short range. The first time I heard the Div 7 channel used I was hearing a motorist assist unit on the Beltway east of I-95. I was in Leesburg at the time. Today while at Rt29/Rt243 waiting for the Obama motorcade to pass I heard a unit mentioning Rt 50 and Gore, VA.

Speaking of the motorist assist units, they are no longer Car5##. They are DOT###.

 

[GROCKSHD]

Speaking of the motorist assist units, they are no longer Car5##. They are DOT###.

In Division 5 they are M 5##

 

[c5corvette]

Maybe I am missing something obvious but I was hoping someone could fill me in on why they need 40 something different frequency combinations for the DVRS? I could see a couple of different combinations for special events but they are short range so why does each divison need a different assignment?

The primary reason is because with the advent digital radio and talkgroups, there are a multitude of 'channels' available in various 'zones' (or 'banks' if you will) of a radio. Becasue the DVRS system has the ability to allow the portable to essentially change the channel of the mobile radio, each zone in the mobile radio has to have a corresponding frequency assigned (not because it needs a seperate frequency, but because each zone needs to be independent from one another.) Refer back to my primer of how the DVRS works.

As far as short range, some of the DVRS transceiver units have seen output of 10 watts - that much power on 700 MHz can undoubtably travel from Harrisonburg to Staunton or Stafford to Prince William (thus crossing VSP division lines.) So, when freqhopping and everyone else is hearing these signals from afar they are really hearing the DVRS, not the XTS5000.

Hope this helps.

 

[MOTORHEAD3902]

hmm, i get the idea someone doesn't like the capability, so they question the need.

Why pick at the 40 freq pairs? What's it hurting?

 

[Samuel]

BA-
Not a matter of liking or not liking....just curious from a technical standpoint what the rational was. You have to remember most of us locals don't have mobile extenders at all so Im not really that familiar with them. I never listened to the mobile extenders on the old system and I doubt I will on the new one. Trust me I am happy for you all that you finally have a quality radio system. Sorry if the question came across as saying it needed to be justified...that was not my intent. Just pure curiosity.

 

[c5corvette]

...just curious from a technical standpoint what the rational was.

I commend you for asking (and I whack 39o2 on the head for picking on you.)

All I can say is its very complicated and your curiosity is justified. Believe me, even reading the STARS user manual won't help people figure this one out.

While most of the VR channel pairs appear dedicated to an agency or division, they are really dedicated to 'Zones' in a radio codeplug, keeping in mind that many of the zones are common across agencies such as the national interop and state intraop stuff.

 

[MOTORHEAD3902]

Sorry, midnight shift in the swamp got the better of me...I shouldn't be so quick on the key. My apologies...

And thanks for the insight into the mystery boxes in my trunk, C5. Interestingly, and I dont know if this is a facet of design or a byproduct, but when my portable affiliates through the DVRS of a "specialty" unit, it repeats what is coming across THAT guy's mobile unit channel selected. This includes TG's that I do not have access to normally, like SURV and DES. They show up on my portable display identified by TG #, not by name. Weird, huh? I first noted this while assisting a specialty team, and was quite surprised.

 

[c5corvette]

Sorry, midnight shift in the swamp got the better of me...I shouldn't be so quick on the key. My apologies... .

Swamp? Its okay this time! I am sure I too screw up now and then. And, it seems I see you at least once a year, so you can whack me on the head where ever we meet up next (Williamsburg is 2011 I think.)

And thanks for the insight into the mystery boxes in my trunk, C5. Interestingly, and I dont know if this is a facet of design or a byproduct, but when my portable affiliates through the DVRS of a "specialty" unit, it repeats what is coming across THAT guy's mobile unit channel selected. This includes TG's that I do not have access to normally, like SURV and DES. They show up on my portable display identified by TG #, not by name. Weird, huh? I first noted this while assisting a specialty team, and was quite surprised.

That is sort of by design. The intent is that the first DVRS (myster box as you called it) active or on a scene is the only DVRS activated - that is by design. A by product of that is what you describe and that is that only the portable associated with that DVRS will control that DVRS. Being able to control the mobile radio through the portable is a very intelligent process called over the air channel streering. Thus when a second portable shows up and 'affiliates' with the active DVRS the second portable will be talking on what ever TG or channel the mobile rig is set to (and if the mobile is scanning you will inherit those recevied channels as well as if you were a bystander listening with your scanner.) Not sure I would call that 'by design' -- but essentially it is.

 

[MOTORHEAD3902]

Swamp, indeed. A lovely place called "Jones Hole Swamp", smelling of dirty laundry and reefer, but that's neither here nor....dude- WHAT?

...not to give too much away, but the primary user was most...uh...surprised when I could hear the discrete TG on my walkie.

 

[n4jri]

So this discussion now advances our technical knowledge. Let me ask for a couple of clarifications:

1 - I've wondered if P25 simplex TG's might be the mechanism of channel steering--largely based on the idea that the portable TG must match the mobile TG in order for the portable to access the VHF system via the DVRS. Can anything of the mechanics of channel steering be elaborated on?

2 - From the 'primer' and other recent comments, it looks like a portable set to a given zone will hear both the DVRS and other portables on freq no matter which TG (in the mobile's current zone) it's set for. So let's say a Hanover trooper assists a Goochland or Louisa trooper without changing channels. Once he arrives on scene, will his portable interface with their portables (presumably on RICH_1) even if his is on RICH_2? I'm also reading from recent comments that his DVR would not activate if another DVR on Zone1 is already on scene. Just trying to confirm.

3 - Maybe a more bottom-line version. Am I correct in thinking that the portable will hear whatever is on the DVR's 700 freq no matter what TG in that zone it's set to---BUT unable to speak back on VHF through the DVR unless it's TG matches the mobile's?

73/Allen (N4JRI)

 

[c5corvette]

So this discussion now advances our technical knowledge. Let me ask for a couple of clarifications:

1 - I've wondered if P25 simplex TG's might be the mechanism of channel steering--largely based on the idea that the portable TG must match the mobile TG in order for the portable to access the VHF system via the DVRS. Can anything of the mechanics of channel steering be elaborated on?

2 - From the 'primer' and other recent comments, it looks like a portable set to a given zone will hear both the DVRS and other portables on freq no matter which TG (in the mobile's current zone) it's set for. So let's say a Hanover trooper assists a Goochland or Louisa trooper without changing channels. Once he arrives on scene, will his portable interface with their portables (presumably on RICH_1) even if his is on RICH_2? I'm also reading from recent comments that his DVR would not activate if another DVR on Zone1 is already on scene. Just trying to confirm.

3 - Maybe a more bottom-line version. Am I correct in thinking that the portable will hear whatever is on the DVR's 700 freq no matter what TG in that zone it's set to---BUT unable to speak back on VHF through the DVR unless it's TG matches the mobile's?

73/Allen (N4JRI)

I am glad these discussions help the hobbist understand how this works.

Gone are the days of a box in the trunk that has a portable hidden inside to patch the audio back and forth.

Without going into the intelligence in the DVRS, I will say that you just 'elaborated' and you answered your own question in #1.

I believe from what Motorhead described above he may have more information on your other two questions. Unfortunately, your questions would be specific to VSP radios and scenarios (and not necessarily other agencies who usually stick to a single zone and a single corresponding VR designation.)

 

[WA4MJF]

c5corvette, I'm curious who does own the STARS. You say it is not the VSP. Here in NC, the NCSHP owns, installs, operates and maintains the VIPER system, although many Federal, State and local outfits use it.

Thanks

 

[c5corvette]

c5corvette, I'm curious who does own the STARS. You say it is not the VSP. Here in NC, the NCSHP owns, installs, operates and maintains the VIPER system, although many Federal, State and local outfits use it.

Thanks

VSP is like the system manager, but its owned by VITA.

Furthermore its licensed to:
Virginia Information Technology Agency
11751 Meadowville Lane
Chester, VA 23836



For more information on STARS I would suggest you visit Statewide Agencies Radio System (STARS)