State of Delaware - P25 Phase 1 System (2024)
- Thread starter trailhiker73
- Start date
Very interesting
Checked for new control channels in the 7-8 band this morning from Frederica, Crickets...
hey
Member
Look for a NAC:3A7h
last evening I did create a search on my sds100 for 3A7 from 850-858mhz. I did receive many tkgps transmitting on some frequencies with the specific P25 Nac. The most active frequencies transiting voice where 852.6000, 853.08750, 852.3500, and 852.8375. The information that did not display was the Site number or Sys ID. The Tkgps I could figure out are listed below. There were a few 3 digit tkgps all Encrypted. I assuming they are law enforcement. At 8pm there was a lot of talk over tgkp 145 so I'm assuming its DSP Suscom doing a roll call. I saw no activity over 700mhz matching the Nac 3A7.
It appears that: Sussex Fire Dispatch - 277 and 1877
Fire 2- 223, Fire 3- 225,
Ems 3- 791 Ems 2- 281
Med Patch - 283
Unknown if training or fire company tkgp- 769 ( heard Mayday drills over it )
CMLF tkgp- 381
It appears that: Sussex Fire Dispatch - 277 and 1877
Fire 2- 223, Fire 3- 225,
Ems 3- 791 Ems 2- 281
Med Patch - 283
Unknown if training or fire company tkgp- 769 ( heard Mayday drills over it )
CMLF tkgp- 381
Hmm, what control channel was used for these? All those voice channels are currently used and active in the SmartZone system. While it seems theoretically *possible* that the new and old cores are coordinating their use on both systems, I sort of doubt it because it would be using vital / limited channel resources by transmitting the same info on two tgs and frequencies (one Smartzone and one P25) simultaneously.
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I have received Data burst only on 853.58750 and 852.5875mhz ( no Nac on data burst only )
I received Data burst and voice over 852.08750, 852.6000, 855.9625 mhz.
I received voice only over 852.3500, 853.08750, 851.8500, 851.3625
On 856.3875, 855.8375, 854.5625 no voice or burst, just stops on those frequencies and flashes the Nac 3A7
lastly no Nac displayed and only static noise over 850.03750, 854.0125mhz.
855.8375mhz just displayed Nac 3A7 and site 3 , still no Sys ID.
still working on getting more information.
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I'm doing a channel analysis rn and I don't see any DE licensed frequency in use other than those being assigned by the SmartZone system. I have a video processing on YouTube rn, and I'll post a link when available.
Yeah I surely don't have all the answers , but I do know that Sussex fire Disp simultaneously transmitting on the smartzone tkgp 4432, and on 800mhz Nac 3A7 under both tkgps 277 and 1877. Also Fire 2 and 3 , Ems 2 and Ems 3 on both the smartzone and under the Nac 3A7. I would love to figure it out so I could program my G5.
OK, define what you mean by NAC 3A7. Is this a site NAC, or a sysid? You would need the control channel to program it into your G5. I suppose you could try what's current on the system. I'm curious why the site number is exactly the same (3) as as what is used by the SmartZone system. P25 systems use a different format.
I tired to post a picture of my screen but radio reference says it’s big for the server. I also tried to send you a private message and the same thing happen. I think a picture would explain.
Yes it would. If you pm me, I'll send you a email address.
Ok, the video is up:
The window on the right side is the channel activity for range of frequencies licensed for and used by the Sussex site 3. The steady spike on the right side of the window is centered on the current control channel for the site: 853.5875. The top pane in the left window shows the control channel in red, the alternates in yellow, and the voice channels assigned to the site and defined by data carried on the control channel. As talk group become active, they show in the top pane what frequency / voice channel that they have been assigned. On the right window, you see the corresponding RF energy spike at the frequency that the talk group was assigned. Note that only the SmartZone system is controlling RF energy on those frequencies.
The window on the right side is the channel activity for range of frequencies licensed for and used by the Sussex site 3. The steady spike on the right side of the window is centered on the current control channel for the site: 853.5875. The top pane in the left window shows the control channel in red, the alternates in yellow, and the voice channels assigned to the site and defined by data carried on the control channel. As talk group become active, they show in the top pane what frequency / voice channel that they have been assigned. On the right window, you see the corresponding RF energy spike at the frequency that the talk group was assigned. Note that only the SmartZone system is controlling RF energy on those frequencies.
853.5875 is the smartzone control channel for site 3 Sussex
852.5875 is not licensed in DE, but is used in Carroll County MD
852.0875 is a site 3 smartzone voice channel
852.600 is a site 3 smartzone voice channel
855.9625 is a Worcester County MD channel
852.350 is a site 3 smartzone voice channel
853.0875 is a site 3 smartzone voice channel
851.850 is not licensed in DE, but used in Baltimore City
851.3625 is a site 3 smartzone voice channel
856.3875 is a DelMarVa Power channel at the Millsboro site
855.8375 is a DelMarva Power channel at the Whaleysville site
854.5625 is a DelMarVa Power channel at the Millsboro site
850.0375 is not a valid public safety frequency
854.0125 is not licensed in DE but used in Baltimore County
Some of these frequencies not licensed in DE may be used in New Jersey; I sometime receive NJ traffic when in the Lewes / Rehoboth area.
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OK, I am able to reproduce what @fireboat61 is seeing wrt NAC 3A7. My working theory is that a new base station radio is being selected to transmit when the source RID is 65520 which is a system reserved RID judging by its 655xx range. Sometimes that source RID will alternate with a legacy console RID but not always, but the channel grant is being directed by the SmartZone control channel / system. The source RID 65520 doesn't seem to care from what console it originally came from, whether a state police, local police, or Sussex County dispatch position. There are TGIDs being carried on the subchannel as is typical with P25 system as well as a NAC; unclear if this is a channel NAC or a site NAC since the frequeny range is being scanned conventionally (not via a control channel.) 859.4125 is Excelon / DMV Power freq hosted on the Whaleysville site. Interestingly, the NAC alternates bewteen 3A7 and 1C3, 1C3 being the site NAC for the Whaleysville site. Very interesting find as the system transitions.
EDIT: My XTS and the SDS100 were receiving the exact same transmission simultaneously. I see in the system's wiki page notes a P25 NAC of 3A7 for the SmartZone system, so I'm guessing that this is simply a channel NAC, and not a site NAC or sysid.
EDIT: My XTS and the SDS100 were receiving the exact same transmission simultaneously. I see in the system's wiki page notes a P25 NAC of 3A7 for the SmartZone system, so I'm guessing that this is simply a channel NAC, and not a site NAC or sysid.
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Looking at other SmartZone systems across the country with P25 voice, it is not uncommon to see a P25 NAC in their wiki data. This leads me to conclude that seeing a P25 NAC associated with a Delaware system voice channel does not indicate that the new P25 system is on the air. More likely that the NAC has always been there, but the data was suppressed when a scanner is programmed to track a SmartZone system - I'll be looking into this hopefully later today. The interesting thing is the display of TGIDs when doing a range search using an SDS scanner. I'm not sure if this is a bug or real data. People might want to start logging this data and compare it to what actually happens when the P25 system comes online for real. Below is a pic provided by @fireboat61. Note thae "P25 800 Sys" is a user created label for a Custom Search.
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I sent up a conventional scan list of all the LCNs / channels being used by the Sussex SmartZone site, and have been watching the tgids. I *suggest* that anyone who has the time or inclination to begin logging these tgids and mapping them to existing tgids on the SmartZone system. If I have time, I'll set up a wiki page where they can be recorded and cross-verified by the community. There is no guarantee that these tgids will actually become the operational tgids on the new P25 system, but it is possible - and and at this point I think probable. Not a promise to set it up, but I'll try.
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Adding to all of this, what you do NOT see when monitoring the frequencies are the sysid, rfssid, or wacn. Also, the RIDs seem to be the same ones used in the SmartZone system. I need to set up a test of montoring a P25 system and scan it conventionaly to see if that info is displayed by the SDS.
EDIT: trying the same technique with a P25P2 system does not work, likely because of the 2-slot TDMA schema.
EDIT: trying the same technique with a P25P2 system does not work, likely because of the 2-slot TDMA schema.
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One last observation before I need to get back to work - 6 of the 10 channels on the Sussex site seem to display the NAC and the tgid. They may or may not be the "favored" channels for the system (possibly to mitigate interference), or they may be the site base stations that have been upgraded so far, not sure - It's a mystery. Still waiting for a 9600 P25 control channel to come up - doubtful they would risk flipping a switch one day to migrate over without a period of testing.
The six channels are: 852.600; 853.0875; 851.3625; 852.350; 852.8375 and 852.0875.
The six channels are: 852.600; 853.0875; 851.3625; 852.350; 852.8375 and 852.0875.