Trunked system question

[Volfirefighter]

RE: https://www.radioreference.com/apps/db/?sid=10207

What is a DMR Conventional Networked system? How does it work with only one channel per site? I want to try and scan this when I get my SDS100.

 

[mtindor]

Not every "DMR Conventional Networked" system in the DB is set up accurately. But for those that are, basically its a case where they are typical standalone repeaters in diverse areas that are connected over IP and carry the same traffic / talkgroups simultaneously. Although each site on a networked DMR system could have talkgroups that are only carried locally on that site as well as talkgroups that are rebroadcast over all sites.

So they are just your typical DMR repeater (like hams often set up), but networked over IP to extend the coverage.

Look at Jackson Co Ohio for the Conventional DMR Networked system down there. They have quite a few repeater locations, each on a different frequency and each covering a specific area of the county. Specific talkgroups can serve only a particular local site, and other talkgroups may be broadcast over all sites simultaneously. Not sure how Jackson is specifically set up in that regard though.

 

[GTR8000]

Also known as Motorola MOTOTRBO IP Site Connect

MOTOTRBO IP Site Connect - Motorola Solutions

As Mike said, it's basically just individual repeaters linked via IP to create a wide area network of sorts. It's not a trunked system, however.

 

[Volfirefighter]

Thanks. I would have guessed that was how they worked. I was confused because it is listed in the DB under trunked systems and I could not imagine how it could function as a trunked system without at least two channels, one control and one voice.

 

[GTR8000]

It's considered a pseudo-trunked system for RRDB purposes, since the talkgroups are usually common/shared among all repeaters that are networked. For the ham DMR systems especially, where you can have dozens of talkgroups available at dozens of sites, it would be a nightmare trying to maintain them all as separate conventional listings within each county where there's a site active.

It's worth noting, though, that you can actually have a "trunked" site on a single frequency. Harris P25 offers VDOC or "Voice/Data on Control", where when idle the single-frequency repeater acts as a control channel, until an affiliated radio transmits, at which point it becomes a voice channel. At the end of the transmission, it reverts to control. There are similar solutions from other manufactures, although they are intended only for extremely limited traffic fill-in sites.