360 gps updates per minute per channel?!?

[Wile E. Coyote]

I have some XPR4550 radios that I am using in conventional, and we were thinking of upgrading to a digital format so we could take advantage of GPS location updates.

Before V 1.07 firmware, you could only have a max of 30 to 40 updates per minute per channel. This is far too slow for our needs and a fleet of our size (400+ units). With the new firmware, they boast that you can now have up to 360 per minute per channel because it addressed the problem with colissions. If this is true, I will have to rethink going digital again.

Is anyone using the GPS feature on Motorobo? If so, does this new firmware really work? Real-life examples would be great.

Thanks,
WEC

[RFguy]

It is a new feature called "Enhanced GPS" and it uses syncronization to maximize channel loading. Yes, 360 units with one minute updates per channel (2 timeslots) with basic GPS data and low voice traffic (voice would have to be on a second repeater to get the 360 units level).

You can get up to 540 units with one minute updates on 2 repeaters and have one time slot for voice traffic.

The more voice traffic it effects the eficency of GPS updates so the numbers go down.

The new system planner has lots of info on this.

[Wile E. Coyote]

All of the planners I am finding online are from 2009. Where can I find the new one?

[RFguy]

The newest is version "M" on MOL. I'm not sure if there is another location other than MOL.

[Bill_G]

Wow. We set our gps updates to 300 seconds for slightly over 600 fixed route buses and almost 300 paratransit buses, and let the mapping software extrapolate the points in between. We can touch a bus in CAD and get the current actual location if an update is over 30 seconds old. The bus also updates it's location after the operator presses one of the canned messages. The button event is stored as what, where, and when for later retrieval and analysis. While it's true the travel for fixed route buses is planned and predictable, lift buses go everywhere any time of the day depending on the passengers and destinations they are assigned. So, the mapping software predictive portion for fixed route is dead on because it is based on the schedule, and sometimes wrong when tracking a lift bus. All of this is done over a UHF conventional channel using 2400 baud fsk with a quasi-synchronous tdma polling sequence aka scada. Each bus has 40ms to key, transmit, and dekey. That's 30 per second using old fashioned radio augmented with an application. Trbo is catching up.

[Wile E. Coyote]

Thanks RFguy, I eventually found the new planner, but it does not describe how GPS location updates play with voice on MotoTRBO.

For example, can a MotoTRBO mobile have a voice conversation on time slot 1, and still be able to send GPS data using time slot 2 at the same time?

I just need to sit down with a demo and figure some of this stuff out.
WEC