Hi all,

I'm experiencing a poor WLAN performance with the DM3730 Torpedo module if using it in ad-hoc mode. Especially, the uplink speed (sending from the Torpedo module) is very low. The module is used in the development kit and an antenna is connected to it. Both sides are running iperf version 2.0.5.

My measurement results are the following:

# iperf -i 5 -t 30 -c 192.168.254.101 -r -w 128K
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size:  256 KByte (WARNING: requested  128 KByte)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.254.101, TCP port 5001
TCP window size:  256 KByte (WARNING: requested  128 KByte)
------------------------------------------------------------
[  5] local 192.168.254.123 port 37057 connected with 192.168.254.101 port 5001
[ ID] Interval       Transfer     Bandwidth
[  5]  0.0- 5.0 sec  5.00 MBytes  8.39 Mbits/sec
[  5]  5.0-10.0 sec  5.00 MBytes  8.39 Mbits/sec
[  5] 10.0-15.0 sec  4.88 MBytes  8.18 Mbits/sec
[  5] 15.0-20.0 sec  5.00 MBytes  8.39 Mbits/sec
[  5] 20.0-25.0 sec  4.88 MBytes  8.18 Mbits/sec
[  5] 25.0-30.0 sec  4.88 MBytes  8.18 Mbits/sec
[  5]  0.0-30.1 sec  29.8 MBytes  8.28 Mbits/sec
[  4] local 192.168.254.123 port 5001 connected with 192.168.254.101 port 41971
[  4]  0.0- 5.0 sec   390 KBytes   639 Kbits/sec
[  4]  5.0-10.0 sec   389 KBytes   637 Kbits/sec
[  4] 10.0-15.0 sec   383 KBytes   628 Kbits/sec
[  4] 15.0-20.0 sec   397 KBytes   650 Kbits/sec
[  4] 20.0-25.0 sec   380 KBytes   622 Kbits/sec
[  4] 25.0-30.0 sec   396 KBytes   649 Kbits/sec
[  4]  0.0-32.8 sec  2.50 MBytes   638 Kbits/sec

I've also tested the Torpedo module as a WLAN station connected to an access point. Then the measurement results look better. The uplink speed is even higher now than the downlink.

$ iperf -i 5 -t 30 -c 192.168.254.101 -r -w 128K
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size:  256 KByte (WARNING: requested  128 KByte)
------------------------------------------------------------
------------------------------------------------------------
Client connecting to 192.168.254.101, TCP port 5001
TCP window size:  256 KByte (WARNING: requested  128 KByte)
------------------------------------------------------------
[  3] local 192.168.254.100 port 57472 connected with 192.168.254.101 port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0- 5.0 sec  7.50 MBytes  12.6 Mbits/sec
[  3]  5.0-10.0 sec  7.00 MBytes  11.7 Mbits/sec
[  3] 10.0-15.0 sec  7.00 MBytes  11.7 Mbits/sec
[  3] 15.0-20.0 sec  7.25 MBytes  12.2 Mbits/sec
[  3] 20.0-25.0 sec  7.38 MBytes  12.4 Mbits/sec
[  3] 25.0-30.0 sec  7.38 MBytes  12.4 Mbits/sec
[  3]  0.0-30.1 sec  43.6 MBytes  12.2 Mbits/sec
[  5] local 192.168.254.100 port 5001 connected with 192.168.254.101 port 60365
[  5]  0.0- 5.0 sec  10.4 MBytes  17.5 Mbits/sec
[  5]  5.0-10.0 sec  10.3 MBytes  17.2 Mbits/sec
[  5] 10.0-15.0 sec  10.3 MBytes  17.3 Mbits/sec
[  5] 15.0-20.0 sec  10.3 MBytes  17.4 Mbits/sec
[  5] 20.0-25.0 sec  10.3 MBytes  17.2 Mbits/sec
[  5] 25.0-30.0 sec  10.2 MBytes  17.1 Mbits/sec
[  5]  0.0-30.0 sec  61.9 MBytes  17.3 Mbits/sec

What I also recognized is that the CPU usage of the torpedo is high when it is in station mode (both when sending and when receiving). This means that the CPU is around 10% idle and 60-70% irq/312-wl12xx. However, the CPU usage is low when the module is in ad-hoc mode and it is sending (around 87% idle, 8% irq/312-wl12xx).

Any ideas how to improve the WLAN performance in ad-hoc mode? Has anyone experienced the same issue?

Thanks