I was speaking P25 VHF to P25 7/800 and there are plenty of systems that run analog to P25 just fine, you just need a radio tech experienced enough to do so.
Regards,
-Frank C.
California Radio Interoperable System (CRIS)
- Thread starter mcjones2013
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Regards,
-Frank C.
Nice blip this morning as I was watching the system...Confirms my suspicions about TDMA.
Regards,
-Frank C.
Regards,
-Frank C.
kj6psg
Member
So far, all the activity I have observed has been TDMA.
I've seen some, RID11044, as FDMA at times or not marked as TDMA in DSD+.
Regards,
-Frank C.
From my understanding (limited), the system is TDMA with FDMA fallback if an older subscriber connects to the TGID. So theoretically, a 6 radio site would have 10 voice channels, (with the control being FDMA? (internal voice) or can a control be TDMA and a P1 subscriber still see the TDMA control? Probably not.) If a P1 subscriber comes on, that bonks a radio with 2 timeslots down to 1 FDMA channel. And that drop to FDMA is site/radio specific right? If it's a linked TGID with other sites down the state, and a P2 subscriber comes on a different site, it's getting the traffic across TDMA I believe.
With that assumption, we're only seeing TDMA because PSCO techs are all simply using P2 capable radios for their testing and service work.
I know a few system managers lurking here are laughing, but I also know most of them probably left after the 3rd page. (waves hi)
With that assumption, we're only seeing TDMA because PSCO techs are all simply using P2 capable radios for their testing and service work.
I know a few system managers lurking here are laughing, but I also know most of them probably left after the 3rd page. (waves hi)
Yes you are mostly correct. FDMA will force the local machine to all FDMA and P2 subscriber radios will follow/track traffic fine on the same machine. The rest of the state tuned to that TG will receive it on whatever setup they have there...
Regards,
-Frank C.
Reality is that the state won't be able to come up with enough VHF-High frequencies that would have exclusive statewide authorization. The CRIS system information posted on the OES website states that VHF cross patching with any other frequency band will be built into the system. This is the primary objective of building this system. It will be a patch and crossband system. The CHP has about 6-8 SUV's with that capability, but it takes time to get those rigs to incidents. CRIS is going to be permanent and available on a full time basis, at least in areas that can be covered by 700/800 MHz frequencies. I'm going to watch with great interest if the rural northern and Sierra Nevada counties end up with sites. A vehicle mounted system makes much more sense in those areas.
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Why would they need statewide authorization? The VHF frequencies would only be used in the area the site(s) cover. Just as an example, if they transitioned all of the existing Santa Cruz County VHF frequencies to P25 trunking they would have plenty of frequencies to use in a simulcast "Santa Cruz County" VHF CRIS site (not saying they are or should do this). Also, this site wouldn't necessarily be owned by the state, it would/could be owned by the municipalities in Santa Cruz County but would be connected to the state core.
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mmckenna
I ♥ Ø
True, but they only have two county wide VHF fire channels. Put one aside for a control channel, you now have a one channel trunking system. Awesome...
They do have other VHF channels for fire, but those are tactical/fire ground simplex channels.
Take the 2 county wide VHF sheriff channels, and now you have a 3 channel system, or 6 TDMA slots. But now you have to share that with Sheriff, Fire and all the other agencies that utilize SO red.
I just went through the process of trying to secure 2 VHF pairs in that county, and was unsuccessful. The agencies in Santa Clara County and Monterey County are running 700MHz trunked systems, yet still have all their VHF pairs and won't release them.
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Where should those of us interested in operational updates to the CRIS system post if we are not interested in receiving notifications on and reading about and wading through general system design, engineering, the CHP, and the virtues of frequency bands in various topologies?
It's easy to say "don't read it" but when these off-topic dick measuring contests clog the thread it really sucks when looking for information specific to CRIS as it continues to evolve. Can we keep it on topic? When CRIS advertises VHF in the band plan, I will be the first to let you all know.
It's easy to say "don't read it" but when these off-topic dick measuring contests clog the thread it really sucks when looking for information specific to CRIS as it continues to evolve. Can we keep it on topic? When CRIS advertises VHF in the band plan, I will be the first to let you all know.
mmckenna
I ♥ Ø
It is. And it works.
I agree. I made a point about the article that was posted based on real facts and discussions with the County radio shop. Usually that sort of info is welcome. Not sure why there had to be so much philosophizing about ways to make it work when it's not likely to happen.
That aside, we're likely going forward with the Harris XL-200's and will be researching putting them on CRIS for the 'free' interop/mutual aid talk groups.
More activity on 4501 Loma at 0935 this morning. Seems that Felton Fire was running a training exercise using this talk group. Heard ref to E2336 and Utility 2397, which belong to Felton. Radio IDs: 94417 94418 94434 94436 All phase 2. Ended quickly.
mmckenna
I ♥ Ø
That should be interesting to watch. There's a lot of shadowing of Loma in the Felton area, so coverage should be interesting. I'm not aware of Netcom having CRIS capability, so unsure how they are going to dispatch for them.
I know CRIS had loaner radios for agencies to try out, might be worth watching those 944xx series radios to see where they pop up again, might mean someone is trying them out.
ScannerDude244
Member
I remember this facebook post about Felton fire getting APX because of the CRIS system. Are local govs allowed to program the CRIS into their radios?
mmckenna
I ♥ Ø
Didn't know Felton FPD had gone with APX-8000's. For a small cash strapped agency, that's a lot of radio. So that probably suggests they may not be borrowing loaner radios to try this out.
The post about about the FEL talkgroup would suggest they do have their own talkgroup on the system. Dispatch is still handled by NETCOM via Fire Red, and when I was at NETCOM a few weeks back, I didn't see any CRIS radios.
Going with a multiband radio makes some sense, even though all the fire agencies in the county are on VHF. If they do go to CRIS, and it works well enough for the area, then good for them. Glad to see they'll maintain VHF capability.
My understanding, so far, is that agencies will program their own radios. CRIS supplies the radio ID, system key, and necessary info. No doubt the state is providing templates to assist setup.
Will be interesting to see how this plays out. 700MHz is still a poor choice for that area. I know what 800 will do up there, and it's not good. Loma Prieta is not in the best location for coverage in that area, but if it works, it works.
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I think it may be important for people to stop thinking of CRIS as just a 700 MHz P25 trunking system and more for what it is, a Motorola ASTRO 25 M Core. The 700 MHz P25 trunking system is just one sub system (RFSS) of the total M Core. I have attached a PDF detailing the capabilities of the ASTRO 25 Core.
On a somewhat related note, I have also attached a document for a Budget Change Proposal for the replacement of portable radios for the CHP. In the proposal they outline the requirements for new radios/radio systems under the CAPSCOM Strategic Plan. Some takeaways that were interesting to me;
"Standardized voice and data solutions must be deployed across agencies to the extent possible. The new enforcement vehicle modular land-mobile radio systems available today can be integrated with other digital voice communications systems, such as Voice over IP and Radio over IP technologies currently used by the CHP and other local, state, and federal agencies." - I was not aware CHP was using this, this can also be a sub system of the ASTRO 25 M Core.
"The CAPSCOM Strategic Plan provided a vision where California would establish a “System of Systems” architecture and infrastructure. The plan specified the state would prepare to procure shared systems in the next five to ten years (from 2010). This project is strongly aligned with the CAPSCOM Strategic Plan and serves to continue the state's vision of a “System of Systems,” which is currently being installed by the Governor’s Office of Emergency Services, Public Safety Communications." - This would be the ASTRO 25 M Core we now know as the CRIS.
On a somewhat related note, I have also attached a document for a Budget Change Proposal for the replacement of portable radios for the CHP. In the proposal they outline the requirements for new radios/radio systems under the CAPSCOM Strategic Plan. Some takeaways that were interesting to me;
"Standardized voice and data solutions must be deployed across agencies to the extent possible. The new enforcement vehicle modular land-mobile radio systems available today can be integrated with other digital voice communications systems, such as Voice over IP and Radio over IP technologies currently used by the CHP and other local, state, and federal agencies." - I was not aware CHP was using this, this can also be a sub system of the ASTRO 25 M Core.
"The CAPSCOM Strategic Plan provided a vision where California would establish a “System of Systems” architecture and infrastructure. The plan specified the state would prepare to procure shared systems in the next five to ten years (from 2010). This project is strongly aligned with the CAPSCOM Strategic Plan and serves to continue the state's vision of a “System of Systems,” which is currently being installed by the Governor’s Office of Emergency Services, Public Safety Communications." - This would be the ASTRO 25 M Core we now know as the CRIS.
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To better explain this with something that was heard on the system, it's POSSIBLE that Felton was talking on an analog (or P25) conventional channel that has been tied in to a talk group on the 700 MHz P25 trunking system via the CRIS M Core.
"you are on the wrong channel, you should be on FEL TAC DIR which is not on the repeater, but direct and should be the next channel over" makes a lot more sense now being that radios on trunking systems usually don't have 'direct' channels programmed as the next channel over. I would be interested in knowing if the second FD repeater that was mentioned in the news article as being back on the air soon is now on the air and has P25 capability and if that may be what they are using. It's also POSSIBLE that they are talking directly on the 700 MHz RFSS.
As for the way this thread is going, if people would rather keep it about what has been heard/seen on the 700 MHz P25 trunking RFSS of the CRIS and not talk about the larger aspects of what may (or may not) be tied into it that's okay with me but if we weren't talking about that stuff we likely wouldn't figure that stuff out.
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phipac
Radio & Scanner Enthusiast
Most voice channel grants I have seen are on 774.81875. And it is definitely Santiago!
de Phil, AD6NH
mmckenna
I ♥ Ø
The 'second repeater' would be the VHF County Fire Yellow secondary dispatch channel. I have a that channel at a few of my sites, and it hasn't been changed to P25 as far as I know. I'd be involved in bringing in the IP network for that, and that hasn't happened.
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