Somebody asked on another forum what the problem was with the MDUs that KHP is using now in the KC Metro. Here's a brief (well, somewhat brief) explanation of why in mostly layman's terms. I though some of you "antenna heads" (ha ha) might like to know.
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Here's why they don't work in the metro:
Troop A uses three radio systems:
#1 - Piggy-backed off of the Johnson County Sheriff's Office analog trunk
#2 - Piggy-backed off of KCKPD's analog trunk
#3 - Digital P-25 system (new and NOT so improved)
The Leavenworth & Miami County troopers use the digital system. The Johnson & Wyandotte County troopers uses the JOCO trunk primarily and the KCK trunk secondary, depending on where they are in WYCO. Dispatch simulcasts across all three systems. If the radio is on one system, you can't hear anybody besides dispatch on the other system. So when on digital, you won't hear JO/WY troopers, just LV & MI.
The MDUs run off of the digital system. Are you beginning to see a problem yet? If not, here it is:
The in-car radio has to be on the digital system in order to run tags, use the MDU for anything other than as a regular computer, etc. The radio is the modem basically and it has to have a connection with the radio.
Problem #1 - If the in-car radio is on digital, you can't hear your partners in JO/WY. You will only hear what dispatch repeats back. So for all you know, somebody could be a mile down the road from you trying to stop a vehicle that is failing to yield, fighting with someone, out checking a drunk driver, needing another car for a search, may have just pulled up on a crash, etc, and you won't know it until dispatch repeats it back IF THEY DO.
Problem #1a - The in-car radio is on digital for the MDU, so you have to keep your portable radio on the analog trunk to monitor your partners.
Problem #1b - Obviously the portable radios don't have as great of coverage as the in-car radio, so if you get further north (say, north of I-70), you can't get out on your portable on the JO trunk and it's hard to hear too, so you have to switch to the KCK system on your portable. Now you're back to problem #1, not being able to hear the majority of your partners on the Johnson trunk.
Problem #2 - The digital system lacks greatly in coverage. Northeast of I-635 on I-35, it's nothing but garbled crap. East of about US-69 on I-435, same thing. You can't hear anything, you can't make out anything anybody is saying and you surely can't transmit. You get a long low, "out of range" tone when you try to transmit and the radio shows, "OUT OF RANGE". There are plenty of places when driving around that the radio will start making that low out of range tone, so obviously if you got into something, you'd be without a radio. The digital system is like digital TV - it's either on or off. At least with analog, you might be able to make out a scratchy transmission or a weak transmission cutting in and out, but with digital, it's pretty much all or nothing.
Problem #3 - KDOT has said it's basically NEVER going to get any better. They need to put a tower on top of KU Med for the northeast part of Troop A, but for some reason that's not possible right now. I don't know if it's funding (probably) or butting heads with KU Med or what the deal is. Speculation on my part, but I assume it's mostly funding among other things.
Problem #3a - This MDU thing was KHP's, not KDOT's. From the looks of it, there was not adequate research put into it (e.g. - contacting the local agencies in KC to see what has worked and not worked for them, contacting MOSHP who has had MDUs for years or KCMOPD for the same reason). Those agencies have since switched from using the radio for the MDU connection to wireless cards, which works much better.
Problem #4 - On the KCK trunk, you can scan KCKPD and switch over to their channels to go direct with them if necessary, which the helicopter does quite frequently. On the JO trunk you can monitor inter-city (a mutual aid type channel for the Johnson County PD's). On the digital, you can't do that. All you get is KHP. You're kind of out of the loop on digital.
Problem #5 - The volume is really weird on the digital. The troopers are very quiet but dispatch will blow you out of the car. It's a constant up/down volume control for almost EVERY transmission. When driving fast with wind noise and sirens in the background, it's very difficult to hear anything, even with the volume on max.
Problem #6 - When using the MDU to run something, VOICE transmissions take prescedence over DATA transmissions. So if you run a tag then somebody talks on the digital, your tag gets pushed to the back burner. Every time somebody talks, your tag keeps getting pushed back down the line until all the voice data is finished. It's annoying and defeats the purpose when you can just pick up the mic, run the tag and get it back within seconds, all the while without trying to type and read a computer screen as you're driving 70 mph down the interstate.
So there you have it. That was a long explanation, but that's pretty much the deal in a nutshell. These problems aren't necessarily in a specific order or order of importance, just as they came to me while I was typing.
Furthermore, the comments contained herein are only my opinions based on my experiences and limited technical knowledge of the radio systems. Do not confuse my opinions for anything besides one "end user's" opinions.
___________________________________________________
Here's why they don't work in the metro:
Troop A uses three radio systems:
#1 - Piggy-backed off of the Johnson County Sheriff's Office analog trunk
#2 - Piggy-backed off of KCKPD's analog trunk
#3 - Digital P-25 system (new and NOT so improved)
The Leavenworth & Miami County troopers use the digital system. The Johnson & Wyandotte County troopers uses the JOCO trunk primarily and the KCK trunk secondary, depending on where they are in WYCO. Dispatch simulcasts across all three systems. If the radio is on one system, you can't hear anybody besides dispatch on the other system. So when on digital, you won't hear JO/WY troopers, just LV & MI.
The MDUs run off of the digital system. Are you beginning to see a problem yet? If not, here it is:
The in-car radio has to be on the digital system in order to run tags, use the MDU for anything other than as a regular computer, etc. The radio is the modem basically and it has to have a connection with the radio.
Problem #1 - If the in-car radio is on digital, you can't hear your partners in JO/WY. You will only hear what dispatch repeats back. So for all you know, somebody could be a mile down the road from you trying to stop a vehicle that is failing to yield, fighting with someone, out checking a drunk driver, needing another car for a search, may have just pulled up on a crash, etc, and you won't know it until dispatch repeats it back IF THEY DO.
Problem #1a - The in-car radio is on digital for the MDU, so you have to keep your portable radio on the analog trunk to monitor your partners.
Problem #1b - Obviously the portable radios don't have as great of coverage as the in-car radio, so if you get further north (say, north of I-70), you can't get out on your portable on the JO trunk and it's hard to hear too, so you have to switch to the KCK system on your portable. Now you're back to problem #1, not being able to hear the majority of your partners on the Johnson trunk.
Problem #2 - The digital system lacks greatly in coverage. Northeast of I-635 on I-35, it's nothing but garbled crap. East of about US-69 on I-435, same thing. You can't hear anything, you can't make out anything anybody is saying and you surely can't transmit. You get a long low, "out of range" tone when you try to transmit and the radio shows, "OUT OF RANGE". There are plenty of places when driving around that the radio will start making that low out of range tone, so obviously if you got into something, you'd be without a radio. The digital system is like digital TV - it's either on or off. At least with analog, you might be able to make out a scratchy transmission or a weak transmission cutting in and out, but with digital, it's pretty much all or nothing.
Problem #3 - KDOT has said it's basically NEVER going to get any better. They need to put a tower on top of KU Med for the northeast part of Troop A, but for some reason that's not possible right now. I don't know if it's funding (probably) or butting heads with KU Med or what the deal is. Speculation on my part, but I assume it's mostly funding among other things.
Problem #3a - This MDU thing was KHP's, not KDOT's. From the looks of it, there was not adequate research put into it (e.g. - contacting the local agencies in KC to see what has worked and not worked for them, contacting MOSHP who has had MDUs for years or KCMOPD for the same reason). Those agencies have since switched from using the radio for the MDU connection to wireless cards, which works much better.
Problem #4 - On the KCK trunk, you can scan KCKPD and switch over to their channels to go direct with them if necessary, which the helicopter does quite frequently. On the JO trunk you can monitor inter-city (a mutual aid type channel for the Johnson County PD's). On the digital, you can't do that. All you get is KHP. You're kind of out of the loop on digital.
Problem #5 - The volume is really weird on the digital. The troopers are very quiet but dispatch will blow you out of the car. It's a constant up/down volume control for almost EVERY transmission. When driving fast with wind noise and sirens in the background, it's very difficult to hear anything, even with the volume on max.
Problem #6 - When using the MDU to run something, VOICE transmissions take prescedence over DATA transmissions. So if you run a tag then somebody talks on the digital, your tag gets pushed to the back burner. Every time somebody talks, your tag keeps getting pushed back down the line until all the voice data is finished. It's annoying and defeats the purpose when you can just pick up the mic, run the tag and get it back within seconds, all the while without trying to type and read a computer screen as you're driving 70 mph down the interstate.
So there you have it. That was a long explanation, but that's pretty much the deal in a nutshell. These problems aren't necessarily in a specific order or order of importance, just as they came to me while I was typing.
Furthermore, the comments contained herein are only my opinions based on my experiences and limited technical knowledge of the radio systems. Do not confuse my opinions for anything besides one "end user's" opinions.
