Linking P25 to DMR

[hoser]

Anybody have some experience or ideas for linking 2 systems together...preferably without mobile gateway radios

 

[ka5yth]

I would also be interested. For a pile of money, I hear a Wave Server will do it.

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[Astro Spectra]

For another pile of money the Harris Vida:

https://www.harris.com/solution/vida-transcoder

Without a pile of money you'll have to build it yourself. Without DIY skills you can go with the Rayfield cBridge coupled to a DIU 3000.

 

[aloha]

I've used an Acom Console system to do this too. Which is probably only marginally better than two radios wired back to back. The donor radio setup, is probably the best available without a pile of money.

 

[zap]

You could use two Barix Annucicom gateways to bridge them over a stream.

You could also bridge over SIP if both systems support it.

ESChat has the ability to bridge at the network level but I do not know the cost of it.

 

[shag]

I was thinking about doing exactly that with Cisco IPICS + ISSI GW and SmartPTT on the DMR side. Project's on hold for now, but it should be doable.


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[hoser]

I have a WAVE server and a c-bridge.....

I'd better steer clear of the WAVE server...

I will try the c-bridge route

 

[Astro Spectra]

Be aware that with the cBridge you'll have to shell out for the DVSI $299 USB3000 Standard device and the sub $100 DMK URI audio interface. Plus a DIU 3000. The negative with this approach vs DIY is that the RID is not carried across.

 

[aloha]

Be aware that with the cBridge you'll have to shell out for the DVSI $299 USB3000 Standard device and the sub $100 DMK URI audio interface. Plus a DIU 3000. The negative with this approach vs DIY is that the RID is not carried across.

Is there a solution that would pass Radio ID?

 

[Astro Spectra]

Sure, you can build one yourself. All the necessary bits are available: DMRlink, the DVSI USB3000 Standard for AMBE+ to/from linear PCM $299, and the USB3000 P25 for IMBE to/from to IMBE $499. Drivers for the DVSI USB sticks are available from the company and as part for rtpDir add on for Asterisk. Some assembly required, using Python the batteries are included.

The audio is not going to be as good as a true MBE transcoder but it will be substantially better than back-to-back radios. The cost will be less than 1% of an entry level Cisco IPICS license with the frills needed to do the same job.

 

[hoser]

What of the DVSI Net-2000 unit?

Would this enable it?

 

[Astro Spectra]

No. To link two system together there is more than just audio transcoding involved. To connect to Mototrbo (arguably the most popular DMR system) you need something to emulate Motorola's IPSC IP protocol. That what the cBridge or DMRlink software is for. If your using Hytera networking there is also software out there that does a similar job. Next you need to separate out the audio packets and transcode them between the different forms of MBE coding and that's where the DVSI devices come in but they don't work themselves. They're USB devices and you need glue software to shuttle the audio samples in and out of them. Some of that support is in the rtpDir add on I mentioned in a previous post. Glue software would also need to do the talkgroup and ID mapping task as required, that something the cBridge can't carry between systems. So the cBridge only does half of this for you, just recovering the DMR AMBE+ audio if fitted with a DVSI USB dongle. Finally you need to connect to the P25 system and that means using more software or using the DIU 3000 as I suggested if it's a Motorola network. The DIU will accept 4-wire audio so could be hooked to the cBridge. Another much more expensive option is the Motorola GGM 8000 gateway. If it's not a Moto P25 network, then you'll need an appropriate analog console interface box.

Now I've assumed you mean to interconnect these systems as networked. If you just want to do something cheap and cheerful then back-to-back radios is the off-the-shelf solution. If you are thinking of going this way be aware that you probably want to introduce a programmable audio delay in both directions to allow for the key-up talk permit latency so you don't loose audio (something like the NHRC DAD board). You might want to think of some logic to deal with the busy channel issue when one timeslot on the DMR radio (or P25 if trunked) is on a talkgroup the radio is not set for.

 

[zap]

No. To link two system together there is more than just audio transcoding involved...

And if using Simoco you bridge it over the SIP client which works well with asterisk. Haven't tried on an asterisk app_rpt system.


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[Astro Spectra]

And if using Simoco ...

Using Simoco what?

 

[motorola_otaku]

Probably not what OP is looking for or capable of doing... but a P25 conventional radio, TRBO radio, and P25 trunked talkgroup will all play nice when patched through a MCC console on Astro25 7.x architecture, with remarkably good audio.

 

[hoser]

Maybe I should've stated my end-goal first....but I love what Astro Spectra has been offering up!

I have a ASTRO 7.x P25 system....

I'd love to create a sub-layer TRBO (or even say a Tait or Simoco or ??? DMR III) system that I can inter-connect with the ASTRO system.

Even APX1000 are crazy $$$ for low-tier users on P25

Not sure what the cheapest entry level P25 sub is....but it ain't sub $500-$700 range ....that fo shoe! ;-)

 

[zap]

Using Simoco what?

Infrastructure. Their P25 solution and DMR solutions feature SIP routing to talk groups. Haven't seen it used much on the P25 side but it is there on DMR to support full-duplex calling (or it can be utilized for half-duplex).