VIPER vs NCSHP low band

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CCHLLM

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Since there seems to be a huge amount of confusion about VIPER, NCSHP low band, and interops stuff, here's the skinny.

VIPER is not a state radio system, it is an interoperability system for which the state is the trustee and coordinator. It consists of state, local, and federal infrastructures, and all are sharing their portions of the costs.

There is an 800 mHz radio system that belongs to the state being built out, and included in that infrastructure are substantial portions of the infrastructure for VIPER.

Local and other entities may own their own portions of the interoperability infrastructure.

Interoperability protocols affect only the designated mutual aid frequencies, not the individual operating frequencies of the various agencies involved, though the equipment can be made capable of tying any number of systems and frequencies together on an elective basis when necessary.

Some talkgroups will be shared by all agencies, some will be restricted to respective agency proprietary use, and some will be available to particular authorized users from other departments by agreements between the individual departments.

For municipalities and entities not going with 800 mHz radio systems that match the state's 800 mHz system, their mutual aid frequencies will be interconnected to the interops freqs/talkgroups by the methods appropriate to the type of systems.

A VHF or UHF trunked system that has the matching protocols for any of the participating 800 mHz systems can be seamlessly connected simply by patching together the appropriate system respective talkgroups. This can be a permanent patch or an elective patch.

Some sites are state owned and have local and/or federal infrastructure included.

Some sites are state owned and have no local or federal infrastructure included.

Some sites are local and have state and/or federal infrastructure included.

Some sites are local and have no state or federal infrastructure included.

Some sites are federally owned and have local and state infrastructure as tenants.

Shared sites may utilize shared frequencies for various talkgroups that are not shared.

Federal frequencies are not shared by local or state agencies.

Some designated sites have interconnection systems to tie local infrastructure(s) to mutual aid infrastructure(s) for interops capabilities when and where that capability is necessary.

The NCSHP low band system is going to be around for a good while because it will take some time to fully implement the 800 mHz system.

The NCSHP high band system is being phased out and will not be a part of VIPER.

In those counties where the 800 mHz system is online, 800 mHz portables have been issued, and the high band systems in the cars, including the vehicular repeaters, are being removed. When the troopers are out of the vehicle, they will utilize the 800 mHz portables in place of the high band radios and repeaters.

In those counties where the 800 mHz system is online, the troopers will use the low band when in the car, and the 800 mHz portable when out of the car.

In those counties where the 800 mHz system is online, the low band dispatch only is multicast on the 800 mHz system, but the low band mobile-to-base frequency is not repeated over the 800 mHz system.

Hope some of this helps.
 
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KE4ZNR

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Good Post! I think this deserves a sticky! :)
Hopefully this will help answer some questions about NCSHP's involvment with VIPER...
Marshall KE4ZNR
 

CCHLLM

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Thanx! And I left out the part about the SHP comm engineers, state tv microwave group, the C&L (or whatever they're being called this week) microwave group, the CC&PS computer group, and the various Motorola service agencies being the ones actually carrying out the 800 mHz/digital microwave/VIPER thing.
 
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Bote

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wx4cbh said:
...In those counties where the 800 mHz system is online, 800 mHz portables have been issued, and the high band systems in the cars, including the vehicular repeaters, are being removed. [T]he troopers will use the low band when in the car, and the 800 mHz portable when out of the car.
...
[T]he low band dispatch only is multicast on the 800 mHz system, but the low band mobile-to-base frequency is not repeated over the 800 mHz system.

The above is what I consider to be the essential information of interest to most users reading this thread based on the subject line. Will it be this way indefinitely or are there plans to install trunked radios in the NC Highway Patrol vehicles as well as carrying portables?

Thanx!!
 

CCHLLM

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Once the 800 infrastructure is online, the low band radios will be removed and replaced by 800 mobiles. As to the transition period, I can only speculate on the scenario. Either the 800 and low band systems will be temporarily tied together as a full crossband system where appropriate until all the 800 mobiles are in place, or the 800 mobiles will be installed in the vehicles and both systems will continue to operate as now. Once all 800 mobiles are in place, the low bands will be removed from the vehicles. Since crossbanding is a simple site process via microwave interconnection and console switching actions, I'd say that's most likely the scenario we'll see. The time to carry out this set of logistics among the large number of sites and all the vehicles will be the determining factor for the actual time-line.

A factor in the mix is the question as to where in the consoles of the cars will there be room to put that XTL5000 control head? I would wonder since I was involved in outfitting the cars for duty, and some with all the bells and whistles barely have enough room for what's there now.
 

Bartikus

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In Mecklenburg county I seem to observe a blend of the behavior you describe. Sometimes I hear mobile to base traffic on 800, but the trooper makes reference to "Can you copy me on Low Band?", when I was able to hear him calling Monroe on 800, then also again on low band simulcast ( Still on 800) . But it seems to be sporadic whether or not low band is simulcast both ways... Its much more entertaining when I can copy all of the traffic, particularly in chase situations.

Just FYI.
Bart
 

CCHLLM

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If you hear the trooper talking on the 800 talkgroup, then he's talking on the 800 radio. Low band mobile and car-to-car on the dispatch channel is not repeated over 800, though for most sites, it'd be just a matter of punching down a coupla wire pairs and setting levels. That low band copy inquiry is actually quite common in all the areas that have the 800 talkgroups in service because it's really saying, "I've been callin' you on low band and you ain't answerin'!" This is why the 800 system is gonna make all the difference for the SHP comm situation.
 

JerGoTV3

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Here in NHC. They're also simulcasted over their own TG on the 800mhz. They do that so they can talk to people in the county on the county radio's. So I've picked them up on lowband, NHC 800mHz, and Viper.
 

CCHLLM

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That would be the case anywhere in the state where the 800 system is on line. Just because you hear an SHP conversation on a state talkgroup doesn't mean it's coming over a state site. As explained in the first post of this sticky, VIPER is a plan, not an 800 mHz radio system. VIPER is the interoperability coordination system that enables the use of shared infrastructures. Here again is a simlified version of how the plan works.

Who owns the site doesn't determine whether or not it's a VIPER site.

Some local system sites are VIPER sites, and some are not.

Some state system sites are VIPER sites, and some are not, though supposedly that won't be true eventually.

There is a state 800 mHz system being built out and this system is mistakenly called the VIPER system, though it is the control system backbone of the VIPER plan.

There are local 800 systems that share no state infrastructure components, but do have some state talkgroups in their programming.

There are local and state trunking and non-trunking systems, digital and analog, either up or in the works, that will not be 800 mHz.

Some of the infrastructure is shared and some is not.

The site's position in the control and coverage hierarchy of VIPER determines what kind of site it is, so not all sites will have VIPER capabilities.

Some state sites may support only state frequencies and talkgroups while others are fully VIPER capable.

Some local sites may support only local freqs and talkgroups, while others may be VIPER capable, etc.

You'll hear SHP conversations on SHP talkgroups that are entirely on a local system.

You'll hear SHP conversations on SHP talkgroups that are entirely on the state system.

You'll hear SHP conversations on SHP talkgroups that are on shared infrastructures.

You'll hear various agencies on shared talkgroups on local systems.

You'll hear various agencies on shared talkgroups that are on state sites.

You'll hear various agencies on shared talkgroups that are on shared infrastructures.

If you hear SHP conversations on SHP talkgroups on the NHC system, that means the NHC owned site is or will become a full VIPER site, and probably has shared infrastructure.

If you hear SHP conversations on a NHC talkgroup, that means the talkgroup is shared and is part of the designated interops talkgroup plan within VIPER.

Damn, that was long winded.
 
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JerGoTV3

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I just thought they had a talkgroup. The system in our area that's following the VIPER plan is not connected to the existing 800mhz County system.
 

Grog

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All of the new cars I see are using the "short" (if that is ever true for low band :D ) Black Larsen NMOs using L brackits.

They are using more of the Wimpallas. Poor guys don't have a chance to drive a real car :lol:
 

CCHLLM

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Some of the Rockingham County and Person County cars have the 1/4 wave whips because of the lack of low band transmitter and receiver sites in those counties. I know, I installed some of them. :D I understand there are some in the mountain counties, too.

The longer the wavelength, the larger the corresponding ground plane area. You're already compromising the antenna's effectiveness by shortening the rod and adding a matching coil at the bottom to make up for the loss of the 1/4 wave length, so let's add a bracket and compromise the antenna coupling some more so we can save some money. Hey, it only makes the whole thing even more directional and only degrades the performance in some directions by 9db, and we dont have to fix a hole in the side of the car. Besides, who cares how well it works as long as it saves money and makes us decision makers look good at budget time? That leaves more money to spend on promotions and cosmetic bull**** instead of replacing 50 year old radio systems and antique radars and cameras. Right?

Sometime I'll tell ya how I really feel.
 
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russellfd

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shp

Can anyone tell what 800 fregs i need to enter to recive SHP I cant understand how the viper stuff works I have a BC96d Uniden scanner
Thanks
Russell
 

milf

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Firstly, find the sites nearest to where youll monitor.
Second, program in the CC's if they are known.. if not, program in ALL the freqs.
Program them as Motorola.
Program in as many of the TG's as you need.
Scan away.
NOTE: Depending on where you are, you may or may not get anything on the VIPER as its still in buildout. You can stil depend on Low Band in MOST areas of the state.
 

Harlock

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This is such a great thread.

I'm a little new to the area, and don't know what the VIPER system is... What is the VIPER system? If you can point me in the right direction, I'll catch up on the rest.

Seeing as I know my scanner can pick up freqs in the 800MHz range (Radio Shack Pro-29), I'd be interested to know if anything I've scanned is considered VIPER.

Check out my 800MHz scans from 8/3/07 in the NC Scans area

-H-
 
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52to12

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For an explanation of the VIPER system go to the RR database for North Carolina.Scroll down to state of NC VIPER At the end of the site/freq. lists there are several links to check out. The blog by PBOY is very informative.Also,the post by wx4cbh is another good explanation. For info on the conventional system check the Dept. of Crime Control on the NC data base.
 
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