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 Posted:  Mon Jul 16 2018, 10:28am | | | Posted by: Darkstar350 | Posts: 811
| | | | | Location: Central Nassau
| | Joined: Mon Aug 18 2014, 10:57pm
| It looks like the county is adding P25 emissions to what appears to be the freqs from the EDACS system
[link]
[ Edited Mon Jul 16 2018, 10:30am ]
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| | Posted: Mon Jul 16 2018, 05:08pm | | | Posted by: ipfd320 | Posts: 1864
| |  | | | Location: Martin County Florida
| Account terminated as requested
| Joined: Sat Mar 31 2007, 02:05am
| HERE is the *****RPC8 APPROVAL LETTER_3984-3983------*(Hmmmmmm----I Wonder How they are Going to Seperate the Users for the P-25 Side)*
July 3, 2018
Ms. Elizabeth Bella
Police Communications Supervisor
Nassau County Police Department
1194 Prospect Avenue
Westbury, NY 11593
Re: Region 8 Approval - 800 MHz Applications – Nassau County, NY
Dear Ms. Bella:
Region 8 received two 800 MHz applications from the Nassau County Police Department in June of 2018, via
CAPRADAP for two new base station locations, with sixteen (16) 800 MHz NPSPAC channels. The new base
station locations are in Elmont and Bayville, New York. Further the County is seeking to add the P25 emission
designators to all frequencies and locations.
.
Base Transmit (MHz)
851.1875 (Ch. 14)
851.3375 (Ch. 26)
851.5875 (Ch. 44)
851.6250 (Ch. 47)
851.7375 (Ch. 56)
851.8375 (Ch. 64)
851.9000 (Ch. 69)
852.1125 (Ch. 84)
852.1500 (Ch. 87)
852.1750 (Ch. 59)
852.9000 (Ch. 145)
853.1750 (Ch. 165)
853.4250 (Ch. 185)
853.5750 (Ch. 197)
853.6500 (Ch. 203)
853.7250 (Ch. 209)
The Region has completed its review of the application and based on the technical parameters included in the
applicant’s FCC forms and supplemental documentation, the application is a minor application as it fits within the
existing licensed service area under FCC Call Sign WNNM884, and the Region approves application
CAP18060411003983 and CAP18060412003984 as submitted. | | Back to top | | |
| | Posted: Mon Jul 16 2018, 09:06pm | | | Posted by: Darkstar350 | Posts: 811
| | | | | Location: Central Nassau
| | Joined: Mon Aug 18 2014, 10:57pm
| Intresting stuff
I suppose now its looking more like the county may "convert" the 800mhz system to P25 for the users of that system and maybe either keep the 500mhz system dedicated mainly for police or build the 700mhz system for that purpose
Its understandable why they would want to keep the 800mhz freqs
From what i gather 800mhz freqs are hard to come by and many times these days if one lets them go they would most likely be taken by some cell company...
[ Edited Mon Jul 16 2018, 09:08pm ] | | Back to top | | |
| | Posted: Wed Jul 18 2018, 04:07pm | |
| Posted by: w2lie | Posts: 2824
| | | | Old Display Name: w2lie
| Location: Long Island, NY
| Your Admin
 Premium Member | Joined: Fri Nov 04 2005, 03:28am
| I heard a rumor that is now several years old that Nassau was going to swap the EDACS system for P25 because they could use the same back end controller, and that it would allow for easier interop between the two systems.
While that may or may not be true, what is true is that EDACS is yesterday's technology and that if anyone wants a new system, it is going to be P25. I'm curious if Nassau also has any filings for 700MHz frequencies as well. | | Back to top |       | |
| | Posted: Thu Jul 19 2018, 12:45pm | | | Posted by: ipfd320 | Posts: 1864
| | | | | Location: Martin County Florida
| Account terminated as requested
| Joined: Sat Mar 31 2007, 02:05am
| There was a Thread on Nassau having 700 Freqs Allowcated to them and it was a Whole Lot of them--Ill Have to Start Searching Also----Hmmmmm
I Found the Thread---- *(Nassau County 700MHz Trunk System (Official Rumor Thread)*---- [link]
I Tried Searching the FCC Database and Nothing would Come Up for Frequencies Just Microwave Path Locations---Hmmmmm
[ Edited Thu Jul 19 2018, 12:59pm ] | | Back to top | | |
| | Posted: Sun Jul 22 2018, 01:34am | | | Posted by: GTR8000 | Posts: 190
| | | | | | | Joined: Fri Nov 25 2016, 07:07am
| Nassau already has two 700 MHz licenses, WQUM833 and WQUT752. They are licensed for 18 total frequencies at 8 sites, configured in two simulcast cells like the T-Band system (9 frequencies each).
Keep a few things in mind:
1) For practical purposes, 700 and 800 MHz are considered a single band. It is quite common for P25 systems to feature a mixture of frequencies from both slices of spectrum, not only on the same system, but at the same site. The subscriber radios don't really care if they're switching between 772.01825 for one transmission, then 854.5875 for the next transmission. It's all seamless.
2) The county already has a Motorola ASTRO 25 core and zone controller for the T-Band system, so adding 700/800 sites and repeaters is a walk in the park. The two 700/800 simulcast cells will simply become sites 3 and 4 of the 1AE system.
3) Referring back to point #1, the county can build out the new sites using the 700 MHz frequencies, transitions all of the EDACS users to that system, then once the EDACS system is off the air, they can continue to build out the new sites by adding the now-vacated 800 MHz frequencies. The EDACS system has a control channel and 15 voice frequencies, which is the same capacity as they have with 700 MHz frequencies. Two cells of 1 control channel plus 8 voice frequencies, with TDMA that gives you the same 1+16 that EDACS currently has. So absolutely no loss of capacity during that transition.
4) Once the 800 MHz frequencies are combined with the 700 MHz frequencies at each site, you wind up with 2 simulcast cells of 26 frequencies each, which equates to 50 voice paths for each cell with TDMA. That is more than the current T-Band system and EDACS system combined, and by quite a margin. So ultimately, they could transition all of the T-Band users to the 700/800 sites and wind up with everyone on the same page.
There are other options, such as converting the EDACS system to P25 gradually, basically a few repeaters at a time, until everyone is cut over to P25. The wildcard in all of this is the fact that the county deals with Motorola for the T-Band ASTRO 25 system, and with Harris for the 800 EDACS system. It makes the most logical sense for them to get everything on the 1AE Motorola core, since as Phil mentioned once everything is on the same system, it's very easy to setup talkgroups that can be used on T-Band, 700, or 800 seamlessly.
Should be interesting to see how they go about it as it unfolds.
Edited to add: I should clarify that the maximum concurrent voice calls an ASTRO 25 simulcast can handle is 36. So while they could in theory combine all of the 700 and 800 MHz frequencies, for practical purposes there's little point in having more than 18 voice repeaters, as that would constitute the limit with TDMA operation.
[ Edited Sun Jul 22 2018, 07:35am ] | | Back to top | | |
| | Posted: Mon Jul 23 2018, 04:20pm | | | Posted by: Darkstar350 | Posts: 811
| | | | | Location: Central Nassau
| | Joined: Mon Aug 18 2014, 10:57pm
| There would definitely be a need for 2 systems such as for example the 700mhz system dedicated mostly for police use, and 800mhz for the other county services because the PD has alot of traffic alone, add the hospital , DPW , OEM and whether the NICE buses will want talk groups on the new system or not that is much traffic for both systems
But perhaps having both a 700 and 800mhz system will make way for better interop capability , dealing with the same company for both systems, etc..
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| | Posted: Mon Jul 23 2018, 05:32pm | | | Posted by: GTR8000 | Posts: 190
| | | | | | | Joined: Fri Nov 25 2016, 07:07am
| Darkstar350 wrote ...
There would definitely be a need for 2 systems such as for example the 700mhz system dedicated mostly for police use, and 800mhz for the other county services because the PD has alot of traffic alone, add the hospital , DPW , OEM and whether the NICE buses will want talk groups on the new system or not that is much traffic for both systems
But perhaps having both a 700 and 800mhz system will make way for better interop capability , dealing with the same company for both systems, etc..
There is really no need for two separate systems. A P25 system can handle an enormous amount of traffic, it simply depends on how many repeaters each simulcast cell has. TDMA doubles the voice capacity per repeater, and a single simulcast cell can handle up to 36 simultaneous transmissions. That is quite a lot of capacity.
Even if they did keep the 700 and 800 simulcast cells separate, they would still likely share the same 1AE core and zone controller, and thus would be a single system. | | Back to top | | |
| | Posted: Mon Jul 23 2018, 09:04pm | | | Posted by: Darkstar350 | Posts: 811
| | | | | Location: Central Nassau
| | Joined: Mon Aug 18 2014, 10:57pm
| GTR8000 wrote ... Darkstar350 wrote ...
There would definitely be a need for 2 systems such as for example the 700mhz system dedicated mostly for police use, and 800mhz for the other county services because the PD has alot of traffic alone, add the hospital , DPW , OEM and whether the NICE buses will want talk groups on the new system or not that is much traffic for both systems
But perhaps having both a 700 and 800mhz system will make way for better interop capability , dealing with the same company for both systems, etc.. There is really no need for two separate systems. A P25 system can handle an enormous amount of traffic, it simply depends on how many repeaters each simulcast cell has. TDMA doubles the voice capacity per repeater, and a single simulcast cell can handle up to 36 simultaneous transmissions. That is quite a lot of capacity. Even if they did keep the 700 and 800 simulcast cells separate, they would still likely share the same 1AE core and zone controller, and thus would be a single system.
True there is no *absolute* need for separate systems as you described 7 and 800mhz are almost the same band so another option would be to build out one big system with both the 700 and 800mhz freqs or such as for example the new Suffolk P25 system having some 800mhz sites, some 700
Also not sure if anyone else has noticed this but for whatever reason in the Nassau 500mhz bandplan my 996xt picks up a 700mhz freq?
I will try and screenshot to make sure im not imagining something  ...
[ Edited Mon Jul 23 2018, 09:07pm ] | | Back to top | | |
| | Posted: Tue Jul 24 2018, 03:03am | | | Posted by: GTR8000 | Posts: 190
| | | | | | | Joined: Fri Nov 25 2016, 07:07am
| Yes, Suffolk's P25 system features a mixture of 700 and 800, but an even better example of how there is really no difference between 700 and 800 with these systems is the Union County simulcast cell of the NJICS system, which features frequencies from both spectrum on the same site.
[link]
And the Somerset County system is a good example of how you can mix bands on the same system with no problem, their system having a T-Band simulcast cell alongside a 700 simulcast cell. Talkgroups on that system can be setup to operate on either band, or both bands at the same time, without the users knowing any different. You can talk to me on TG 645 with your T-Band radio and I'll talk back to you with my 700 MHz radio, no problem. The system doesn't care, it all goes through the same zone controller and core.
[link]
It's not surprising that the 1AE system is broadcasting 700/800 bandplan entries. Here's is what the NYC DoITT 3A8's system bandplan looks like. Note the first four 700/800 mixed bandplan entries, which is the default Motorola bandplan for an ASTRO 25 system operating on 700 MHz, followed by two T-Band entries, presumably for future conversion of the T-Band SmartZone system C820 to P25.
Bandplan 0: Base=851.00625 Offset=-45 Spacing=6.25 BW=12.5
Bandplan 1: Base=762.00625 Offset=+30 Spacing=6.25 BW=12.5
Bandplan 2: Base=851.0125 Offset=-45 Spacing=12.5 BW=12.5 Slots=2
Bandplan 3: Base=762.00625 Offset=+30 Spacing=12.5 BW=12.5 Slots=2
Bandplan 4: Base=480.00625 Offset=+3 Spacing=6.25 BW=12.5
Bandplan 5: Base=480.00625 Offset=+3 Spacing=12.5 BW=12.5 Slots=2 | | Back to top | | |
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