[Bloat] emulating non-duplex media in linux qdiscs

erik.taraldsen at telenor.com erik.taraldsen at telenor.com
Tue Oct 10 04:38:49 EDT 2017


> wifi is not p2p, all data is broadcast to many potential recievers,
> only one can transmit at one time.

On the radio level that is true for the time being.  That may change with 802.11ax, as MU-MIMO is set up to get an multiple sender version.  OFDMA I believe.


> Saying that is half duplex, doesn't work for me. In their example of
> "half duplex", (using push to talk), it still means that everybody on
> that channel hears who is talking. "half duplex" to me, given the
> definition of duplex, means more that there is a *p2p* channel (a wire),
> that you can ping pong data across.

Well, as Mikael stated as well, half duplex has been used on shared medium in the ethernet world since it's inception.  As you state it does not match 100% with the wikipedia definition, but the tradition is there.
 

> This conflation of ideas has always bugged me and I've longed to find
> another word that more accurately describes what happens, therefore
> I've been saying "non-duplex".

Given your distaste for the term half duplex, and the coming advances in .11ax which further confuses the issue, there may be a real need for a better term.  How about starting with a description of the transmission properties and making a set of terms?  Shared medium, single sender, multiple recivers. (current mu-mimo wifi).  Shared medium multiple sender, multiple receivers. (OFDMA 802.11ax if they get it working).  Shared medium entails coordinated action.  Sender/receiver description also encapsulates that there is different behavior in the different direction in the air. 


> > Simplex is one way communication like traditional AM radio.
>
> wifi/lte are not very similar similar to AM radio.

Which was my point. :)   Simplex seems to be a non applicable term here.



-Erik


More information about the Bloat mailing list