[Ns-developers] Traced callbacks in WifiPhy

[Mathieu Lacage]

On Fri, 2009-01-09 at 13:10 +0100, Timo Bingmann wrote:
> Hallo Mathieu,
> i'm running into some ugly problems debugging while the WifiPhy.
> 
> It started out that I wanted to add another parameter to the
> WifiPhyStateHelper::m_rxOkTrace(), i believe it was rxPowerDbm or
> txDuration that i required.
> That didn't work so good, because TracedCallbacks can have only 4
> template parameters.
> 
> So I tried to extend the number of template parameters, but that code
> was too ...erm extraordinary.

Maybe the patch in bug 412 would help ? I had forgot about it and am in
the process of merging it.

> 
> My next plan was to make a WifiPhyTag class and tag the packet with
> lots of useful information collected as it travels through the wifi
> layers. However tags can only have 16 bytes and cannot be updated, and
> the tag must be updated in at least two phases: send and receive (e.g.
> txPower and rxPower).

Tags can contain any amount of information now.

> 
> So the final plan is to group all wifi info, that is "WifiMode txMode,
> WifiPreamble preamble, uint8_t txPower, double snr, ...", into a class
> (proposal: WifiPhyInfo) that is passed through the functions and also
> exported to the trace callback. That also fixes the problem of the
> wifi callback's signature, which throws strange runtime-error if you
> don't get it right.
> 
> Good idea or bad idea?

I think you will be happy with bug 412.

> 
> Also can I rename the WifiPhy::State SYNC -> RX please? SYNC always
> makes me think of preamble synchronizing.

SYNC stands for "synchronized" :)

If you both with a patch to do so, yes. It would also be nice to extend
the state machine with a real SYNChronizing state, even if it is not
used in the current codebase.

regards,
Mathieu