The Digitac Voter reconstructs received data in the Securenet digital voice mode only. On mixed mode systems, the analog audio is processed in same way the SpectraTac worked, it is an analog VF channel. The Astro-Tac processes same way but is for ASTRO or P25 digital modes. In the analog world, if you want to go over the IP and you know the exact time at each site and at the voter (via GPS), the voter can buffer several hundred of milliseconds and wait for all the straggling audio "bits" to arrive. In theory, if later than the buffer depth, those late sites might be ignored. On 3/30/2016 4:53 PM, KM4NRJ FLORIDA wrote:
Maybe I am way off here and there are plans to use voting for digital down the road like Digitac Motorola does. They go further and actually reconstruct packets that fail from a site using data from all sites.
Having said that, in the analog world using Moto SpectraTac comparators for many years it wasn't that noticeable because all was analog from every field receiver in a 1247 square mile County.
With the ADC to DAC process, I shudder at thinking of a timed referencing synchronization of various source sites using public Internet transport. I mean even in the "fire and forget" world of UDP protocol, the network cannot cope.
Unless you are talking private links using microwave unlicensed spectrum technology, I think it may be a hair puller.
Interesting project though.
On Mar 30, 2016 12:30, <app_rpt-users-request@ohnosec.org <mailto:app_rpt-users-request@ohnosec.org>> wrote:
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Today's Topics:
1. Re: Non-RTCM voter, where? (Jeff Ackerman) 2. Re: Non-RTCM voter, where? (Bryan Fields)
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Message: 1 Date: Wed, 30 Mar 2016 09:28:32 -0700 From: Jeff Ackerman <kg6uyz@gmail.com <mailto:kg6uyz@gmail.com>> To: Joe Leikhim <rhyolite@leikhim.com <mailto:rhyolite@leikhim.com>> Cc: info@meshnetworks.co.nz <mailto:info@meshnetworks.co.nz>, app_rpt mailing list <app_rpt-users@ohnosec.org <mailto:app_rpt-users@ohnosec.org>> Subject: Re: [App_rpt-users] Non-RTCM voter, where? Message-ID:
<CAKmcLtJRAnL_-rPHYQHs6cq-eyXY3FmxC-FkNU9rbWUU9+NkYQ@mail.gmail.com <mailto:CAKmcLtJRAnL_-rPHYQHs6cq-eyXY3FmxC-FkNU9rbWUU9%2BNkYQ@mail.gmail.com>> Content-Type: text/plain; charset="utf-8"
XIPAR does not do GPS timing of the audio so there will be no timing of audio. Its called "simple voter", no frills. XIPAR simply selects the best receiver based on DSP signal strength measurements.
On Wed, Mar 30, 2016 at 9:01 AM, Joe Leikhim <rhyolite@leikhim.com <mailto:rhyolite@leikhim.com>> wrote:
> Without GPS, how does XIPAR deal with jitter and network latency? > > > On 3/30/2016 11:25 AM, Jeff Ackerman wrote: > > If you looking for the alternative IP voting of the varuious app_rpt > flavors you can try XIPAR: <http://www.xelatec.com/xipar/simplevoter> > http://www.xelatec.com/xipar/simplevoter > > It wont be as seamless of voting as a RTCM, but its much simpler, doesnt > require anything more then PC's, the IP backhaul and usb radio interfaces > with radios capable of giving discriminator audio. > > Conventional hardware voting comparators could work but require the > backhaul, which in most commercial applications is 4 wire e&m voice > circuits using either tone signaling or e&m signaling. (This method of > voting is done outside of allstar/app_rpt.) > > On Wed, Mar 30, 2016 at 8:09 AM, Joe Leikhim <rhyolite@leikhim.com <mailto:rhyolite@leikhim.com>> wrote: > >> Here are some products to start with; >> >> There is the Raven M4x >> >> http://www.ravencomm.com/documents/products_doc3_23.pdf >> >> Raytheon JPS SNV-12 (Though the future of this product is up in the air, >> it was the defacto standard. Uses 600 ohm VF circuits, IP connectivity >> needs to be overlaid) >> http://www.simulcastsolutions.com/userfiles/file/appnotes/vSnv12App.pdf >> >> Motorola Spectra Tac (Obsolete Now Motorola has pretty much abandoned >> analog FM technology. Uses 600 ohm VF circuits,) >> http://www.repeater-builder.com/motorola/spectra-tac/spectratac-index.html >> >> The above voters all use some method of signal/noise voting. The JPS >> SNV-12 and the Raven M4X use DSP to make decision, while the Spectra Tac >> was pretty much an analog noise measurement vs a status tone/audio AGC >> level. The SpectraTac does not support non-Motorola receivers unless you >> know the "secret sauce" which I am privy to. >> >> This site has some practical examples of projects that are simulcast, but >> by design incorporate the SNV-12 voters. >> >> www.simulcastsolutions.com <http://www.simulcastsolutions.com> >> >> Are you looking for some more in depth RF design aspects of receiver >> voting? I can help perhaps. >> >> Joe >> >> www.leikhim.com <http://www.leikhim.com> >> >> >> On 3/8/2016 5:20 AM, Steve Wright wrote: >> >>> On 05/03/16 06:00, mike@midnighteng.com <mailto:mike@midnighteng.com> wrote: >>> >>>> FYI There are RTCM /voter systems for app_rpt if you want to do it >>>> right. >>>> >>>> >>> Is there an example voting-RX project somewhere I can read about? >>> >>> Non-RTCM please. I know about the RTCM and I'm looking at alternatives. >>> >>> >>> Many thanks, >>> Steve >>> >>> _______________________________________________ >>> App_rpt-users mailing list >>> App_rpt-users@ohnosec.org <mailto:App_rpt-users@ohnosec.org> >>> http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users >>> >>> To unsubscribe from this list please visit >>> <http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users> >>> http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users and scroll >>> down to the bottom of the page. Enter your email address and press the >>> "Unsubscribe or edit options button" >>> You do not need a password to unsubscribe, you can do it via email >>> confirmation. If you have trouble unsubscribing, please send a message to >>> the list detailing the problem. >>> >> >> -- >> Joe Leikhim >> >> >> Leikhim and Associates >> >> Communications Consultants >> >> Oviedo, Florida >> >> JLeikhim@Leikhim.com >> >> 407-982-0446 <tel:407-982-0446> >> >> WWW.LEIKHIM.COM <http://WWW.LEIKHIM.COM> >> >> >> _______________________________________________ >> App_rpt-users mailing list >> App_rpt-users@ohnosec.org <mailto:App_rpt-users@ohnosec.org> >> http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users >> >> To unsubscribe from this list please visit >> <http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users> >> http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users and scroll >> down to the bottom of the page. Enter your email address and press the >> "Unsubscribe or edit options button" >> You do not need a password to unsubscribe, you can do it via email >> confirmation. If you have trouble unsubscribing, please send a message to >> the list detailing the problem. >> > > > > -- > Jeff Ackerman > kg6uyz@gmail.com <mailto:kg6uyz@gmail.com> > > > -- > Joe Leikhim > > > Leikhim and Associates > > Communications Consultants > > Oviedo, Florida > JLeikhim@Leikhim.com > 407-982-0446 <tel:407-982-0446> > WWW.LEIKHIM.COM <http://WWW.LEIKHIM.COM> > >
-- Jeff Ackerman kg6uyz@gmail.com <mailto:kg6uyz@gmail.com>