Batboard

We are trying out a automatic vehicle location system this spring and we are just trying to brainstorm some ideas about how to pull this off.

All of the squads are currently using 100W VHF Maratracs. One of the issues that was brought up was using the existing radios in the trucks, but a different frequency with AVL Data....

but...

I dont neccessarily agree with this...is it even feasible to channel steer (if that is even possible) the maratrac to another channel just to squirt data, then revert back to our dispatch voice channel??

I know that 100W of power is probably the best we can ask for in this hilly terrain. I am just worried about the channel steering process, and interference with normal communications.

I am pretty new to this AVL setup, so if anyone could shed some light on some of these issues...or brainstorm with me a little on any other important factors I would greatly appreciate it!

- Thanks,
Nick

P.S. This is an EMS organization.

# 1, you need to have the proper Emission designator on your FCC station license for the data.

I agree using a seperate radio frequency IS a GOOD idea. Keeps the humans from going nuts listing to the data burst transmissions.

Now channel stearing, you may be able to do it on the clamshell head, A5, setup because the channel selector is switch contacts.

Will, thanks for the insight.

Seperate radio frequency will definetly be a MUST, and monday morning I will check into the emissions designations.

So far, the AVL systems I have researched have all used a seperate mobile for the data squirt(which obviously there is a good reason why), which I like that idea, but money will be an issue as always.

I see your idea about channel steering the clamshell heads...
but, I see a major issue arising...

how often does this thing squirt data? It probably is programmable/user selectable correct?

But that means everytime it does send data back you are going to hear beep (channel button up/down) beeeeeeeeeeeeep (Simmaron board giving MDC) beep (channel going back)....and will the MDC data interfere with what the computer at dispatch interprets?

how annoying?

and when an ambulance goes to a fire/rescue scene where they have switched to a operations channel or fireground?

Usually they are on channel 1 and lets say channel 2 is the data channel. Normally this would work, 1 up, TX, 1 down and its done. But if they do switch channels for interoperability and say they are on channel 5, whoever is on channel 6 gets punched with data every so often, and dipatch has an MIA ambulance...

I know it seems like I am thinking of some crazy, not so often scenarios, but heck it could happen....

So do you agree a seperate mobile radio would be the better option in this case, maybe even with 100W TPL amp or similiar to makeup for the loss we would get from switching from a maratrac to lets say a radius mobile?

"But that means everytime it does send data back you are going to hear beep (channel button up/down(channel going back)...."


What I was thinking is to isolate the MODE select switch so it gets switched out for AVL Data TX.

") beeeeeeeeeeeeep (Simmaron board giving MDC) beep
and will the MDC data interfere with what the computer at dispatch interprets? "

Why a Cimmaron MDC board? Maratracs do MDC

"how annoying? "

You have that part correct.

I thought Maratracs did MDC too, but turns out the Radius M400 (very very very similiar to the Maratrac) does it, and not the actual Maratrac...

about 90% of our mobiles are Maratracs and the rest are M400's...

You may want to confirm this, but I remember running into this problem when we decided to go with an ANI system, thats why we installed Cimmarrons...

All my Maratracs do MDC. You could have an earlier one or the wrong RSS.

Simple.

Set up the Maratrac for horn/lights on dispatch channel. Each truck will have its own QCII or MDC code. When the code is received, have the radio steer to the "data" channel for a predetermined time set by an ELK or similar timer. Once steered, have a GPS unit dump its serial data in 2400 baud format into the radio. After 30 seconds or so, the ELK timer drops and steers you back to dispatch.
The drawback is that you are leaving your dispath freq for a while. Maybe use a seperate cheapo radio like a CM200 dedicated for data.

When you need to locate a truck, send the proper code and it will steer to the data channel and send you data that can be referenced by several flavors of mapping software on the market.



or just buy a Nextel phone with GPS.

well, i compiled a list of pro's and con's (more con's than anything) to using the maratrac for AVL and we decide to steer away from that option.

Looks like a cheap under dash radio will be making its way to all of our trucks within the year. The downside is you are not getting the 100 W out. But when we identify problems and can determine some deadspot specifics we can compensate with remote site(s) or mobile amps on the dedicated AVL radio...

BTW..will...I check every codeplug for all of our maratracs...none of them have MDC-1200 option...most of them were bought at the same time, but some not... kinda wierd...but its not an issue now..

Thanks for the insight.

Phase I will begin this summer and I will keep you all posted...if you are interested...


Thanks again,
Nick

I had a VHF and UHF Maratrac at one time, with the latest firmware and the latest version of RSS, there was MDC-1200 available on both of them.

Some of your radios might have OLD firmware. The RSS only makes available what the firmware says the radio can do, so if you have an old version of firmware in the radio you won't have access to the MDC options in the RSS.