tcpdump radioTap header does not print signal level

[Gary Pei]

Hi,

I am wondering whether I missed something. I tried to get signal level
from pcap trace. I run the examples /mixed-wireless.py and mixed-
wireless.cc.

Here is the tcpdump command I used: "tcpdump -tt -ne -y
ieee802_11_radio -r mixed-wireless-9-0.pcap".

Here is the output:

0.024232 DA:Broadcast SA:00:00:00:00:00:08 BSSID:00:00:00:00:00:08
LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03:
oui Ethernet (0x000000), ethertype IPv4 (0x0800) : 192.168.0.8.olsr >
192.168.0.255.olsr: OLSR, seq 0x0000, length 40
0.087669 DA:Broadcast SA:00:00:00:00:00:05 BSSID:00:00:00:00:00:05
LLC, dsap SNAP (0xaa) Individual, ssap SNAP (0xaa) Command, ctrl 0x03:
oui Ethernet (0x000000), ethertype IPv4 (0x0800) : 192.168.0.5.olsr >
192.168.0.255.olsr: OLSR, seq 0x0000, length 40

I can not see the signal level in dBm. Do you know what might be the
problem?

Thanks,

Gary

[Nicola Baldo]

Hi Gary,

> I am wondering whether I missed something. I tried to get signal level
> from pcap trace. I run the examples /mixed-wireless.py and mixed-
> wireless.cc.
>
> Here is the tcpdump command I used: "tcpdump -tt -ne -y
> ieee802_11_radio -r mixed-wireless-9-0.pcap".

[snip]

> I can not see the signal level in dBm. Do you know what might be the
> problem?

Did you tell the YansWifiPhyHelper to use the correct PCAP format?
In C++ it would be something like:
wifiPhy.SetPcapFormat(YansWifiPhyHelper::PCAP_FORMAT_80211_RADIOTAP);
I also recommend to read the doxygen documentation for that method:
http://www.nsnam.org/doxygen/classns3_1_1_yans_wifi_phy_helper.html#26df8359f64cf89da92eaf7b5ef0249c

Regards,

Nicola

[Gary Pei]

Nicola,
Thank you so much, it works great!
Best,
Gary

> I also recommend to read the doxygen documentation for that method:http://www.nsnam.org/doxygen/classns3_1_1_yans_wifi_phy_helper.html#2...
>
> Regards,
>
> Nicola