Hi all,
I'm trying to use the gr-ieee802_11 module with bladeRFs to receive/send Wifi packets. However, I am not able to receive anything. Might I add, I am not sure if it is transmitting anything valid either. Here are the things that I have done:
1. Replaced the USRP source/sink modules with osmocom source and sinks respectively.
2. Generated the hierarchical block.
3. Run the wifi_loopback flowgraph and it seems to work. (I am not sure what am I supposed to look at? It shows me the constellation plots for various encodings when I change them, and not all of them are distinct. For example, the 64 QAM 3/4 is very noisy and I believe the estimators are having a hard time decoding it). Console shows packets of the form:
new mac frame (length 524)
=========================================
duration: 00 00
frame control: 00 08 (DATA)
Subtype: Data
seq nr: 9
mac 1: 42:42:42:42:42:42
mac 2: 23:23:23:23:23:23
mac 3: ff:ff:ff:ff:ff:ff
instantaneous fer: 0
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WiFi Tx:
1. Using wifi_tx.grc to transmit. I have not changed the s-mac, d-mac and other parameters (does it matter?). The antenna is a Wideband BowTie Dipole antenna. RF gain values tried are 3dB and 6dB.
2. Put my Wifi card (Netgear WNA1100 N150) into monitor mode and capturing packets using Wireshark. Directly assigning a channel number did not work reliably, so I first configured my Wifi AP and BladeRf Tx to use the same channel before putting the device into monitor mode.
Using this setup, the bladeRF seems to be in use (the Tx LED blinks). Wireshark seems to receive some malformed packets from time to time. Like, I've set the PDU length to 200, but I seldom receive a malformed packet with a length greater than 61. The packet is not decoded properly.
Another scenario:
1. Using wifi_tx.grc to transmit and wifi_rx.grc to receive.
Here, I've tried even a direct line between the Rx and Tx (Tx of the first bladeRF connected to Rx of second with a -20dB attenuator in between). No success here either.
Out of curiosity, I've tried to watch the FFT plot at the Rx bladeRF to see if I can see power levels rise if some transmissions occur. The FFT plot is at 4k FFT with a refresh rate of 20. It is totally silent. For comparison, I tried to see the FFT plot of the Wifi band over the air also. It does show some spiking activity from time to time (which begs the question, what am I supposed to be looking at, but I'll ask that as a separate question).
WiFi Rx:
1. using wifi_rx.grc to receive.
2. Put Wifi card into monitor mode and used the packetspammer utility to inject packets into it. Wireshark capture at the transmitting machine shows packets being put on the interface. I also put my router into 802.11g mode to see if that would work, but I am not sure if it is in pure g-mode or in 802.11b compatibility mode.
No output. What I see at Rx is a fairly continuous value of about 1 unit.
Tried these with all 5,10 and 20msps settings.
Could someone explain what I might be doing wrong?
Regards,
Anshul Thakur