Greensboro\Guilford County, NC MDT's

[ScannerMan929]

Lately, I've noticed that there has been a lack of UHF antennas on the Police cars and several ambulances. These antennas seemed to indicate the precense of MDT's. Although they are gone, the MDT's still remain. Also, the frequency that usually transmitted the MDT data is dead. Has the county\city switched to MDTs via the 800 MHz Trunked System?

 

[CCHLLM]

In a word, yes, but it's not quite that simple. For all practical purposes, they are now on the state/local shared 800 mHz system for the terminals. I wasn't aware that the transfer had been completed since I'm not involved in that part of the ops, but if the old 460.550 freq is dead, then it must be so.

 

[CCHLLM]

In a word, yes, but it's not quite that simple. For all practical purposes, they are now on the state/local shared 800 mHz system for the terminals. I wasn't aware that the transfer had been completed since I'm not involved in that part of the ops, but if the old 460.550 freq is dead, then it must be so.

 

[ScannerMan929]

So there's a state 800 system completely devoted to MDT's?? Wow...I thought NC was in the midst of a budget crunch.

 

[CCHLLM]

That's what the 800 mHz antenna on every SHP and most DMV cars is there for. The trunked data system is statewide now and has been in service in certain areas for a few years. The SHP is and has been 800 voice trunking capable in certain areas where they share their systems with the locals and vice-versa. The state's trunked system is under construction and in two years or so, the entire Dept of Crime Control and Public Safety's fleets will be trunked. It will be mostly analog at first, then all digital within 5 years.

The low band frequencies in use in those with Motorola 800 trunking are on 800 talkgroups in those areas. The troopers carry XTS3000s for that system. Patrol vehicles in those areas with 800 voice capability may not be equipped with the high-to-low crossband vehicular repeater setups in the patrol cars either, though they will likely have a VHF high band radio (Motorola Maxtrac) installed for the VHF statewide repeater system and an MT1000 walkie for same.

And yes, the state is in a budget crunch, but MANDATED communictions upgrades always seem to get funded, especially when the "old" system is so obsolete and difficult to maintain with NO parts availability. This "new" radio system is and has been funded and in the works for some time now. I can't believe so many are completely unaware of its existence, but you aren't by yourself. Check the talkgroups listings for Guilford County and you'll find that there are simulcast talk groups for the SHP. You won't be able to hear the cars talking back unless that unit is actually using the trunked system, but you'll hear the dispatcher.

 

[ScannerMan929]

I know about SHP and only hearing the dispatcher; what frequencies do the police, SHP, EMS, etc. use for the trunked data system? Is it part of the local system with special talkgroups set aside or is it a completely seperate system running parallel to a local voice system?

 

[CCHLLM]

The data channels are all digital data (FSK) on analog channels just as the old 460.550 was, as far as I know. Don't have the info regarding the different services, however it is all talkgroups within the analog system rather than dedicated data channels for each service. I can only assume that as data loads increase, the system will necessarily have to go full digital there, too, as that's the current wave of technology.

 

[ScannerMan929]

You don't have any specifics on frequencies for that system?

 

[CCHLLM]

The freqs would necessarily be the freqs listed in the analog system. The data channels are just data talkgroups among the voice talkgroups within that analog system. There is probably a data traffic control channel in there so that the data units don't "see" the voice side of the system unless there's not enough data traffic to warrant a separate control channel and I doubt that's the case. I can answer that in a short time as I'm expecting a call anytime from one of the state's trunked system gurus.