Hi, > On 1 Feb 2017, at 20:07, Qurat-Ul-Ann Akbar > <quratulannakbar2...@u.northwestern.edu> wrote: > > Hi, > > I have been working with the ieee 802.11 module for GNU Radio. I have GNU > Radio v 3.7.10.1 and I am using USRP N210 with a cbx daughterboard. > > Right now I am just testing if the wifi_rx(the receiver) works. I am using a > wifi card to send beacon frames and trying to detect the frames through the > USRP. I get a lot of messages saying frame too short to parse length(<20). > And there's wireshark connector which is supposed to copy received packets > information into a pcap file and that pcap file shows nothing and the message > that the pacp is possibly corrupted pops up. > > I tried to debug using the data flow. I see the that the frame is detected > properly and the symbols are copied in order to decode and the flow is fine > but after the data is decoded in the WiFi Decode MAC Block, the frame gets > dropped with the checksum wrong message. And it happens for most of the > packets and that's why the pcap file isn't showing anything. > > I tried to play with the gain but that's not changing anything. I am using > 11g beacon frames and the sampling rate on the receiver is 20MHz. Did anyone > encounter the same problem? And why are almost all checksums wrong? It would > be very helpful if someone could guide me on this.
Maybe you can find something useful here: https://www.wime-project.net/installation/ In addition to that, I would recommend to - make sure that there are no Overruns (i.e., that the receiver can catch up with the same stream) - check the constellation plot (it should give you a good idea if decoding works) - try different LO offsets to tune the oscillator out of the band of interest - make sure that frame detection works (i.e., that decoding is only triggered if a frame is sent) Also note that the frame too short message is from the parser. I didn’t implement a complete parser that knows about all sorts of WiFi frames. However, decoding is completely independent from that. If there is a valid WiFi frame it will show up in the PCAP file, even if it’s not parsed and printed to the console. Best, Bastian _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
