MontCo upgrades

[cavmedic]

I'm still trying to figure out thier new SOPs.

So are the End Users......................................

 

[kh11]

Here's what my solution for listening to the new Montco system has evolved into: Raspberry Pi 4B with Rafael Micro R820T USB SDR dongle, running OP25, VNC server and Soundwire server, tucked out of the way on a shelf. Then I'm using VNC Viewer and the Soundwire app on a Fire Android tablet to control it and listen anywhere in my wifi coverage (probably anywhere on the Internet as well if I wanted to go that route). The great thing is that I already had all of the hardware. Total cost was $3.99 to buy the Soundwire Android app (though I could have just used the free version and put up with the announcment every 45 minutes).

 

[cavmedic]

Here's what my solution for listening to the new Montco system has evolved into: Raspberry Pi 4B with Rafael Micro R820T USB SDR dongle, running OP25, VNC server and Soundwire server, tucked out of the way on a shelf. Then I'm using VNC Viewer and the Soundwire app on a Fire Android tablet to control it and listen anywhere in my wifi coverage (probably anywhere on the Internet as well if I wanted to go that route). The great thing is that I already had all of the hardware. Total cost was $3.99 to buy the Soundwire Android app (though I could have just used the free version and put up with the announcment every 45 minutes).View attachment 95333

Have you tried the IP address:8080 of your pi to see if you get the web interface?

 

[kh11]

Have you tried the IP address:8080 of your pi to see if you get the web interface?

Nice - I hadn't tried that yet, but it works like a champ. Clearly I need to dig more into the docs.

 

[cavmedic]

I have found that the black list button only works as a temp lockout and
As soon as you reboot , it comes back. So you have to add the enc talk groups to the black list manually. When you do that , make sure you stop the player first.

I spent about two weeks trying to figure all that out , and thank god I burned images every time I made an upgrade that worked as there was a lot of restarts 😂😂😂

 

[buckyswider]

I started an OP25/Pi thread over on the SDR forum. Maybe I should've kept it here!

kh11, i gotta look into that soundwire thing. Could come in handy. And yep, the web server is cool! over on an sds thread boatbod said it's on his wishlist to code sticky config file changes into the gui. i.e., if you blacklist (or whitelist) something from the web interface, it goes into the config file for the next reboot. A volume control on the web gui is on my wishlist! Could then package a little "scanner" with a small touchscreen and a Pi, speaker, and dongle. Wouldn't be nearly as versatile as a h/w scanner, of course, but the price point is much preferable.

Anyhow, now that OP25 gives me more visibility into the underbelly of the system, I see that the East system has 12 "System Frequencies". I assume this is the number of concurrent conversations that can happen on the system. Does anybody know what capacity of the prior Smartnet system was? Can only recall getting bonked during storms- hopefully this is a much greater capacity than the prior.

 

[maus92]

I started an OP25/Pi thread over on the SDR forum. Maybe I should've kept it here!

kh11, i gotta look into that soundwire thing. Could come in handy. And yep, the web server is cool! over on an sds thread boatbod said it's on his wishlist to code sticky config file changes into the gui. i.e., if you blacklist (or whitelist) something from the web interface, it goes into the config file for the next reboot. A volume control on the web gui is on my wishlist! Could then package a little "scanner" with a small touchscreen and a Pi, speaker, and dongle. Wouldn't be nearly as versatile as a h/w scanner, of course, but the price point is much preferable.

Anyhow, now that OP25 gives me more visibility into the underbelly of the system, I see that the East system has 12 "System Frequencies". I assume this is the number of concurrent conversations that can happen on the system. Does anybody know what capacity of the prior Smartnet system was? Can only recall getting bonked during storms- hopefully this is a much greater capacity than the prior.

If the East Simulcast now has 12 system frequencies, then the RRDB needs to be updated. It's not uncommon that freqs from an old system get moved over to a new system once it is taken offline. Theoretically, if a Phase 2 system has 12 channels, it can support 22 talkpaths. It can be fewer in practice if FDMA subscribers are allowed on the system. The old East simulcast had 10 channels, or 9 talkpaths; the West Simulcast had 7 channels, or 6 talkpaths according to the deprecated SmartZone page. The old cells *may* have had more channels at some point (before the construction of the new system.)

 

[Whiskey3JMC]

If the East Simulcast now has 12 system frequencies, then the RRDB needs to be updated. It's not uncommon that freqs from an old system get moved over to a new system once it is taken offline.

Could this be why they designated the new east simulcast as "Site 3" and west as "Site 4?" Perhaps the old east and west will be sites 1 & 2 if utilized?

 

[buckyswider]

If the East Simulcast now has 12 system frequencies, then the RRDB needs to be updated. It's not uncommon that freqs from an old system get moved over to a new system once it is taken offline. Theoretically, if a Phase 2 system has 12 channels, it can support 22 talkpaths. It can be fewer in practice if FDMA subscribers are allowed on the system. The old East simulcast had 10 channels, or 9 talkpaths; the West Simulcast had 7 channels, or 6 talkpaths according to the deprecated SmartZone page. The old cells *may* have had more channels at some point (before the construction of the new system.)

Aha, cool, thanks, I was wondering why there were two columns for talkgroups on each System Frequency. Why is the formula for Phase II ((freqs-1)*2)? None of the four control channels are listed in the "System Frequencies" table...

I guess I gotta read up on how this Phase II shizzle works!

 

[maus92]

Could this be why they designated the new east simulcast as "Site 3" and west as "Site 4?" Perhaps the old east and west will be sites 1 & 2 if utilized?

In Maryland, SmartX Site Converters were added to support transition from SmartZone to Astro P25. Current SmartZone systems in Montgomery and Howard counties have their new P25 systems labeled as Site 002, where the legacy SmartZone systems are labeled 001.

 

[buckyswider]

Yep, it appears to be the case that all of the smartnet freqs are now included in the P25II system. 6 of the system frequencies are from the smartnet, as well as, interestingly, all 4 control channels are the same four control channels from the smartnet.

 

[maus92]

Aha, cool, thanks, I was wondering why there were two columns for talkgroups on each System Frequency. Why is the formula for Phase II ((freqs-1)*2)? None of the four control channels are listed in the "System Frequencies" table...

I guess I gotta read up on how this Phase II shizzle works!

Can you post a screenshot of what you see?

Each freq is divided into two time slots, meaning for each second, half the time (slot 1) it is transmitting voice (actually data) for tg A, while the other half second (slot 2) is transmitting voice for tg B. In effect, you are doubling capacity of a single frequency - similar to how mobile phones work.

The formula works out this way: (12 system frequencies aka channels) - (1 active control channel) = (11 traffic channels.) If this was a Phase 1 (FDMA) system, that would equate to 11 talkpaths. This is a Phase 2 (TDMA) system, so the 11 traffic channels allow for 22 talkpaths - if no FDMA subscribers affiliate with the system and access a tg. If the system is using IV&D, then a traffic channel can be used for data and is not divided by time thus reducing theoretical talkpath capacity occasionally. IMO, FirstNet / broadband is a better way to deliver data.

As for the control channels not being in the system frequencies table, you may not see the alternates unless they get used as a traffic channel. Depending how the system is programmed, sometimes they are used only as a last resort; in other systems they are in regular rotation. The channel used for BSI is usually fixed, and reserved for that function unless needed for voice. There seems to be lots of variation in the field.

 

[buckyswider]

Can you post a screenshot of what you see?

Each freq is divided into two time slots, meaning for each second, half the time (slot 1) it is transmitting voice (actually data) for tg A, while the other half second (slot 2) is transmitting voice for tg B. In effect, you are doubling capacity of a single frequency - similar to how mobile phones work.

The formula works out this way: (12 system frequencies aka channels) - (1 active control channel) = (11 traffic channels.) If this was a Phase 1 (FDMA) system, that would equate to 11 talkpaths. This is a Phase 2 (TDMA) system, so the 11 traffic channels allow for 22 talkpaths - if no FDMA subscribers affiliate with the system and access a tg. If the system is using IV&D, then a traffic channel can be used for data and is not divided by time thus reducing theoretical talkpath capacity occasionally. IMO, FirstNet / broadband is a better way to deliver data.

 

[buckyswider]

(and yup, i had a brain-o, i meant to name the system "East Simulcast" but typed "East Simplex".... )

 

[maus92]

(and yup, i had a brain-o, i meant to name the system "East Simulcast" but typed "East Simplex".... )

Easily fixed

Yup, the RRDB needs to be updated with the frequencies that migrated over from the SmartZone system. I cannot do it since I am not in a position to verify them off-the-air, but you can... Since this view indicates a 16 channel site (01-004 East Simulcast,) it has 30 possible talkpaths.

 

[phillydjdan]

Could this be why they designated the new east simulcast as "Site 3" and west as "Site 4?" Perhaps the old east and west will be sites 1 & 2 if utilized?

The designation of Zones 3 and 4 don't mean Zones 1 and 2 will be utilized again. They program the system that way in order to program both the old and new systems into all the radios simultaneously. They dont like duplicating Zone numbers. Philly did the same thing when they upgraded from SmartZone to P25 Phase 1.

 

[buckyswider]

Easily fixed

Yup, the RRDB needs to be updated with the frequencies that migrated over from the SmartZone system. I cannot do it since I am not in a position to verify them off-the-air, but you can... Since this view indicates a 16 channel site (01-004 East Simulcast,) it has 30 possible talkpaths.

Yep, I fixed it. I didn't even realize it until I posted the screenshot here!

I submitted a 'ticket' to update the freq list.

So the 30 possible talkpaths implies the secondary control channels can be used for voice traffic, but they're not doing that currently. I guess that's a conscious choice, and if needed they could flip them to voice almost instantly??

 

[phillydjdan]

The alt CCs could be setup to revert to voice if all others are busy. That would make sense

 

[buckyswider]

Aha, cool. I trust the systems were sized to meet expected max traffic. Although if the old system was running on 9 talkpaths, 24 should really be a huge uplift and more than enough so we'd never have to deploy the additional 8 from the CCs. I wonder if there is/was a way to measure latent demand on the smartnet system? Probably not, as the bonks would preclude from a full conversation happening...

 

[cavmedic]

View attachment 95437

Sudo Reboot .......... There was a CC change on the west zone and thats why you see two sites adjacent there. One is the old one and the 853.450 is the one it switched to ... It will refresh with a reboot and go back to one.