Using Two PlutoSDR’s for Full Duplex Packet Radio Communications

Over on his channel SignalsEverywhere, Corrosive has uploaded a video showing us how we can create a full duplex packet radio communications system using two PlutoSDRs. Full duplex is the ability to transmit and receive at the same time. A single PlutoSDR is only half-duplex/simplex because it can only either receive or transmit at any one time. The PlutoSDR is a low cost (typically $99 - $149) RX/TX capable SDR with up to 56 MHz of bandwidth and 70 MHz to 6 GHz frequency range. 

On his video Corrosive explains how full duplex operation is desirable for amateur packet radio communications as it allows for faster and more continuous exchanges.  Demonstrations are performed with his PlutoSDR, SoundModem, EasyTerm, and SDRAngel. Later in the video he also speculates how it might be possible to do things like IP networks via the amateur radio bands with full duplex SDRs.

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FlexMe

> PlutoSDR is a low cost (typically $99 – $149)

I’ve seen this line over and over each time this device comes up….

So some one point me to the $99 (+tax+s/h) site! Please. Digikey and others its quite a bit more to the point its just about outside the $149 listed to START, before, tax, s/h.

At $99 it might interesting, above that, it becomes less so…

I am interest in this device to maybe be the test rig to test out Flex paging reception with SDR’s and multimon-ng….

Any one got a good Flex encoder for all the formats for the Pluto? Oh.. LINUX Only please.

Am

I’ve been doing amateur full-duplex TCP/IP and UDP networking with Pluto devices since last summer. Transfer speeds over the air usually between 150 and 180 kbits/sec.

Corrosive of SignalsEverywhere

Can you provide some detail on how you’re making the network connection with the computer and pluto sdrs?
Those speeds are amazing compared to traditional 1200 and even 9600 baud can do. It’s exactly what i’ve been wanting to do for some time now.

LamaBleu

Hi Corrosive, have a look to charon for data transfer : https://github.com/tvelliott/charon (with mesh support using BATMAN)

Corrosive of SignalsEverywhere

Thar looks awesome! Thanks I’ll look into this.

Mehdi

You say “A single PlutoSDR is only half-duplex/simplex because it can only either receive or transmit at any one time” which is wrong. PlutoSDR can operate full-duplex as well (refer to its official wiki)

Corrosive of SignalsEverywhere

I didn’t say a single PlutoSDR is half duplex, but you need two if you’re going to run full duplex between them and the software I was using was only half duplex.

I’m very well aware the Pluto is full duplex, it’s the only reason I made the above video.
If somehow I did say that, I misspoke

Mehdi

Thanks for the video and clarification

Corrosive of SignalsEverywhere

No problem, thank you!

I wouldn’t make these videos if you guys didn’t watch them.

superkuh

>RX/TX capable SDR with up to 56 MHz of bandwidth

Uh, if you’re using the vanilla pluto software the max bandwidth you’ll get to host over USB is about 4 MHz. It’s really badly implemented using the generic Libiio interface. Using the RX only firmware written by Hoernchen (of osmocom) you can *maybe* get 10 (but usually less).

The AD9363 specs are not the full story and pretending so is approaching fraud, imo. Additionally, the frequency range of the plutosdr is also vastly more limited than 70 MHz to 6 GHz with the default firmware. It’s 325 to 3800 MHz till you hack it.

It’s a really cool device for the price even with these real world lesser specifications. Lets not confuse people with disingenuous statements about the on-board performance (ie, not over USB).

Huzzaher

Huzzah

Hoyeher

Hoy-eh!