[orbit-user] Radiotap header parsing

[Akash Baid]

Hi Guillaume,
Thanks for the diagnosis. Clearly, as you said, your table schema and mine
is different so we don't have the same version. But I installed every packet
related to this application but still I dont get the same schema as yours
(One immediate difference is that you have oml_ts_client & oml_ts_server
while I have just a single oml_ts). Just to confirm, what I did is:

added deb http://pkg.mytestbed.net/ubuntu hardy/ in the
/etc/apt/sources.list
apt-get update
apt-get install the following : libpcap0.8, libpcap0.8-dev, libtrace3 (
libtrace3.0.6) ,libtrace3-dev, liboml, liboml-dev, oml-client.

I also checked with Ivan to confirm that the console on the sandbox has the
latest version of oml-server. I think I am missing some simple point
somewhere. Would really appreciate your suggestion as at to what I should
try out.

Thanks
Akash

On Mon, Aug 24, 2009 at 8:08 PM, Guillaume Jourjon <
guillaume.jourjon at nicta.com.au> wrote:

> Hi,
>
> I think you are not using the latest version of both the trace_oml2 and
> oml2-server during your experiment. Indeed, when I'm running the same
> experiment using the latest debian packages (oml-client and oml-server) from
> http://pkg.mytestbed.net/ubuntu I obtain the following results:
>
> CREATE TABLE trace_oml2_radiotap (oml_sender_id INTEGER, oml_seq INTEGER,
> oml_ts_client REAL, oml_ts_server REAL, tsft INTEGER, rate INTEGER, freq
> INTEGER, sig_strength_dBm INTEGER, noise_strength_dBm INTEGER, sig_strength
> INTEGER, noise_strength INTEGER, attenuation INTEGER, attenuation_dB
> INTEGER, power INTEGER, antenna INTEGER, sourceMAC TEXT, dstMAC TEXT);
> INSERT INTO "trace_oml2_radiotap" VALUES(1, 1, 30.6524909995496, 0.565649,
> 1375296379, 2, 2412, -87, -98, 11, 4, 47111, 42447, -125,
> 1,'00:22:55:ee:b2:90','ff:ff:ff:ff:ff:ff');
>
> In this example let me explain everything:
> - oml_sender id = 1 means that this is the first client using oml that
> connect to the server;
> - oml_seq = 1 means that this is the first measurement for this table;
> - oml_ts_client is the timestamp made by the client but re-interpreted by
> the server that's why you can have some negative values sometimes;
> - oml_ts_server is the timestamp representing the server time when the
> server received this measure;
> - tsft is the Time Synchronization Function timer from the wireless frame
> in microseconds, it is supposed to be an unsigned 64 bits int but we are
> supporting this type yet. It will be fixed soon;
> - rate is Tx/RX data rate and the unit is 500Kbps. In this example
> therefore I have a rate of 1Mbps;
> - freq is the frequency in MHz, in our example we have a frequency of 2.412
> GHz (I'm using 802.11g);
> - sig_strength_dBm and noise_strength_dBm are the signal and noise strength
> in dBm;
> - sig_strength and noise_strength are the signal and noise strength in dB;
> - attenuation is the wireless transmit attenuation;
> - attenuation_dB is the wireless transmit attenuation in dB;
> - power is the transmit power expressed as dBm;
> - antenna is the unitless indication of the Rx/Tx antenna for this packet.
>
> I hope that helps you a bit.
>
> Best Regards,
>
> Guillaume
>
>
>
>
> Akash Baid wrote:
>
>> Hi,
>>
>> I am using the trace_oml2 application of OML2 for libpcap sniffing. I was
>> wondering if someone can help me out with understanding (parsing) the
>> received radiotap data. The schema and an example row entry from the
>> database is :
>>
>> /oml_sender_id INTEGER, oml_seq INTEGER, oml_ts REAL, tsft INTEGER, rate
>> INTEGER, freq INTEGER, sig_strength_dBm INTEGER, noise_strength_dBm INTEGER,
>> sig_strength INTEGER, noise_strength INTEGER, attenuation INTEGER,
>> attenuation_dB INTEGER, power INTEGER, antenna INTEGER, sourceMAC INTEGER,
>> dstMAC INTEGER/
>> /
>> /
>> /"1"// //"16777216"// //"99.76406667032279"// //"-2113757635"//
>> //"369098752"// //"1812529152"// //"-1426063361"// //"-1627389953"//
>> //"201326592"// //"0"// //"0"// //"0"// //"0"// //"33554432"//
>> //"1957724087"// //"1857060791"/
>>
>> So I am trying to guess for example how the freq = 1812529152 corresponds
>> to channel 1 and so on. Also I am getting some negative numbers for oml_ts,
>> tsft; what is the significance of that? Would really help if someone can
>> point me to the appropriate documentation.
>>
>> Thanks
>> Akash
>>
>>
>
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