Hello all,
I need some advice. I'm trying to take UDP datagrams from one port, transport them over an RF link to a receiver, and then send them back over another UDP port. Sounds simple, but I'm having a difficult time with it.
Originally I was doing this to transmit text and image files:
[file source]-->[Packet Encoder]-->[GFSK Mod]-->[UHD USRP Sink (B200)]
[Osmocom SDR Source (BladeRF)]-->[GFSK Demod]-->[Packet Decoder]-->[file sink]
It worked great using files, but once I replaced the File source and sink blocks with UDP source (port 9003) and sink (port 9004), It wouldn't work. I also had to remove the packet encoder and decoder blocks.
[UDP source 9003]-->[gfsk mod]-->[UHD USRP Sink (B200]
[Osmocom SDR Source (BladeRF]-->[gfsk demod]-->[UDP sink 9004]
Troubleshooting: Using Wireshark to sniff the source and sink ports, I could see that the data going to the UDP sink port (9004) was completely different from what was sent on the UDP source port.
When I connect the UDP source/sinks together directly, UDP traffic is passed and the datagrams match.
I removed the radios and connected the GFSK mod/demod blocks directly and the problem persists. Also, unless I decimated the received samples by 8, the datagrams on the UDP sink port were different sizes from those on the UDP source port. The UDP, IP, and Ethernet headers are intact, but the payload on the receive side is just random hex 01 and hex 00.
Has anyone implemented something like this before? What am I doing wrong?
Thank you,