[Ns-developers] WifiMode and WifiModulation

[Timo Bingmann]

Hello Mathieu,

following up on our irc discussion about WifiMode yesterday,
I have made a test repo and applied following changes:
https://idlebox.net/2008/ns-3-wifi/code/ns-3-wifimode/

Renamed WifiMode to WifiModulation and cloned WifiMode, so that both WifiMode and WifiModulation have that singleton design.
A WifiMode consists of two WifiModulations: one for header(+preamble) and one for payload. Furthermore a WifiMode can be mandatory and has long or short preamble.

All code handling WifiModes was adapted, that consisted of
- minor changes in the MAC: basicly just removing WifiPreamble occurances,
- clarity improvements in YansWifiPhy and esp. InterferenceHelper.
- YansErrorRateModel operates on WifiModulations.

I know it's bad to just change semantics of WifiMode, but these really are the right names. Other names would lead to confusion.
And WifiMode is already used by the MAC layers in the right way.

There are a few open issues: one is where to put the preamble length (in us), does it belong into the WifiMode or into YansWifiPhy? Same goes then for SIFStime, etc.

All in all I think the WifiMode changes increase clarity by distinguishing from a modulation; but at the same time decreases the degree that WifiMode is PHY-independent. On the other hand isn't a mode always highly PHY-dependent?

Awaiting your thoughts.
Greetings
Timo