Batboard

Hello,got s customer with all trbo equipment,in analog now,and Mtr 3000 receivets,which we thought of converting to Trbo and use the current SNV12 voting system.Anyone done this? Thanks.

The SNV12 votes the Audio based on the signal to noise ratio of the detected audio which will work fine with FM mode , In Mototrbo digital mode the recovered audio doesn't have the noise component that the voter is making selection based on , therefore SNV12 can not function properly .

Yes, to do voting on a digital system you need to be looking at the parametrics of the bitstream, not the parametrics of the voice - you'd need information from the actual Trbo receiver.

Yes,wowbagger,that is sort of what i was thinking.Plus the more i think about it,i wonder if a person could use a Motorla MIP 5000 Gateway as the link between voter and the Mtr 3000 tac receiver.

There is no voting system for Trbo digital yet. I haven't looked at Trbo analog (yet) to determine if it has the high freq noise content necessary to drive an SNV12 correctly. For now, if the customer really needs voting, and wants to stay single channel, then stay analog with MTR2K or Quantars. OTOH, if they really want to migrate to DMR, then get licensed for additional channels, use Trbo ip site connect, and set the subscribers rcvr threashold to roam to the best local site. The subscriber will do site voting rather than the system doing the voting.

Bill_G wrote:For now, if the customer really needs voting, and wants to stay single channel, then stay analog with MTR2K or Quantars.

Neither of which has been manufactured for at least a year... Those are gone, Bill.

Well I can't speak for the SNV but I can tell you Motorola sanctions the MTR3000 in analog with Digitacs and Spectracs. As the accessory jack has been working for some time on the XPR8400, it stands to reason that model too would be compatible, at least with Motorola product. Just do not think you will ever simulcast from an MTR3000...

Also, I can't seem to find any reference to it, but I could have sworn I read somewhere that Motorola was going to release voting for TRBO TDMA modulation at some point. Don't quote me on that. It's obv being done with Phase 2 so I don't see how TRBO would be much different. You can quote me on the MTR and analog voting, though: http://www.motorolasolutions.com/web/Bu ... 0Sheet.pdf

how wide of an area are they using. could not just go digital and use the IPSC with Multi sites

d119 wrote:

Bill_G wrote:For now, if the customer really needs voting, and wants to stay single channel, then stay analog with MTR2K or Quantars.

Neither of which has been manufactured for at least a year... Those are gone, Bill.

I know, but until I've seen something work well for an application (ie: voting), I can't recommend it. We've done MTR3k stand alone repeaters, and a couple upgrades from MTR2K's, but never placed one into service with a voter. OTOH, we've done lots of IPSC, and that works really well. It's reverse voting, but it does require more licensed channels which can be hard to come by in some markets.

Wowbagger wrote:Yes, to do voting on a digital system you need to be looking at the parametrics of the bitstream, not the parametrics of the voice - you'd need information from the actual Trbo receiver.

Actually no. You just need to recover packets. Signal quality isn't considered. Just uncorrupted packets. All the data streams are shipped to the "voter" via synchronized link so that all the inbound packets are somewhat lined up. Once a good packet is recovered, it's shipped out to the repeater xmit. All the others are dropped in the bit bucket, and the "voter" moves to the next packet. The key is having the inbound arrive within a timing window. Your transport backbone has to be fast, but your bandwidth can be low - usually well under 100kbs - and you buffer the frames on the order of 10ms so they have time to arrive.

Great responses,thank you guys.Like i suspected,Benny from Raytheon daid their voter was not capable brcause of the signal to noise ratio that their voter uses.He said thst hecthought that Motorola was developing something,not sure what,must be some interface or maybe sthird party digitsl voter.He said that he had one fellow in Florida that was using the votet to pass digital audio from a P25 radio back to dispatch,but not a base ststion.I know that Mototrbo works great,but i also knoe i will still have issues with portables,and no voter to help.I was just trying to find a way to utilize their current equipment,to save some money.Instead of ,here try this out at x amount of dollars,while it is still expetimental.


Thanks

Digital Voting for MOTOTRBO (conventional, IPSC, Cap+, and LCP) will be available soon.

John Rayfield, Jr.
W0PM