Tx/rx turnaround on usrp2/xcvr 2450

Hi All,

I’m trying to verify the transceiver operations on USRP2 w/ XCVR 2450
(raw
ethernet driver) using the OFDM tunneling script (tunnel.py). I see a
strange behavior, which I’m unable to parse.

I tried the ping-pong test between two nodes: the node that transmits
the
data fails to receive the next packet that is sent to it (tx->rx switch)
70% of the time. On the other hand the rx->tx switch seems to work fine,
i.e. a node is able to receive data and then transmit it. I also plotted
the peaks thrown by the pn correlation, and the peaks are very
inconsistent

  • though generally missing, which explains that the packet was not seen.

Moreover, I’ve limited the application rate to send a packet once every
0.5s , to ensure that too many packets are not being sent out. The CPU
utilization also looks fine, its a dual core 2.33 GHz that I’m running
and
I’ve not seen the CPU utilization go above 70% on the combined cores.

If I just enable the node as a sender or receiver only, everything seems
to
work fine. Any thoughts?

Thanks,
Apurv