Wichita Falls new NXDN/DMR system

[nd5y]

The past couple days a bunch of DMR or NXDN signals have appeard on the old Wichita Falls PD and FD repeater frequencies that were used before PD & FD moved to the EDACS system. There are also applications pending for two new repeaters. See the complete list at http://wiki.radioreference.com/index.php/Wichita_County_(TX)#Unidentified.2FUnconfirmed_Frequencies

I don't know exactly what type of system this is except it is 12.5 kHz DMR and Unitrunker shows it as NXDN. I don't know if it is trunked or not.

I have no idea who is using these but my guess is that they are moving streets, parks & rec, traffic engineering, water utilities, animal control, etc. from their VHF simplex frequencies to shiny new digital UHF repeaters instead of narrowbanding the VHF radios. Maybe most of the radios were old and not narrowband capable. I don't know.

If they also convert the transit repeater that would give them 7 UHF repeaters with 14 channels assuming that these are NEXEDGE or MOTOTRBO 2 slot TDMA repeaters.

The sanitation repeater 460.350 appears to be dual mode right now.

 

[nd5y]

The other two repeaters were active this afternoon.
That makes 6 so far:
453.1625
453.9
460.275
460.35
460.6
460.625

Unitrunker still shows them as NXDN and DSD shows them as 9600 baud NXDN which as far as I can tell means it is Kenwood NEXEDGE.
I can't get DSD to decode audio yet.

 

[nd5y]

I was right. This explains it all.
http://weblink-public.wichitafallstx.gov/Weblink8_pub/0/doc/145197/Page37.aspx

 

[mmckenna]

MotoTrbo can do the two slots per frequency. Kenwood NexEdge or Icom IDAS can only do one voice slot per channel. But, going from conventional channels to trunked will make a big difference. I run a 5 channel NexEdge trunked system. One channel is a control channel, and the other 4 carry voice traffic. I've got over 300 radios on that system and traffic shows about 25% utilization average.

One way to see if it is a trunked system on NXDN is that there would be a control channel running continuously on one of the frequencies. It will likely switch to another channel every 24 hours, as that is the default setting and pretty much standard.

 

[nd5y]

It appears to be conventional. There is no control channel and there are no periodic data bursts like I have seen on other systems.

 

[nd5y]

I got DSD to decode audio. So far I have heard no encryption. Water Utilities supervisors got hand held radios today and are on 460.625 which they called "Water". I heard a couple of them testing on 460.275 but did not catch what it was called. They also mentioned a talkaround channel. I don't know if this is on the repeater output or one of the old PD simplex channels.