Re: RTS/CTS + CTS-to-self

On Fri, Aug 21, 2009 at 11:55:27PM +0200, Gábor Stefanik wrote:
> 2009/8/21 Johannes Berg <[email protected]>:
> > On Fri, 2009-08-21 at 17:04 +0200, Gábor Stefanik wrote:
> >
> >> I've reworked RTS/CTS since then, just haven't got to sending a new
> >> proposal yet. The current plan is as follows:
> >>
> >> TX_FLAGS & 0x0002: Use CTS
> >> TX_FLAGS & 0x0004: Use RTS
> >> TX_FLAGS & 0x0020: Disable RTS/CTS usage
> >
> > Seems a bit strange, wouldn't setting neither RTS nor CTS have the
> > effect? Seems like 0x20 should rather be "use automatic and ignore the
> > other bits". Anyway, not appropriate here, you should just bring a new
> > proposal.
> 
> The point is that if all bits are 0, auto-setup is used. The problem
> with my original proposal (using two bits) was that an all-zero value
> had different effect than not including the TX flags field (and simply
> swapping "none" and "auto" would result in an illogicality where what
> would logically be "use both" would become "use neither" - just the
> opposite of its logical meaning). Making 0x20 mean "Auto-select
> RTS/CTS", interpreting all-zeros as "Use neither", would have the same
> problem as my proposal - all-zeros is different from a missing field.
> (An empty, zeroed field 15 should have no effect on the process,
> behaving as if field 15 was not present in the header.)

Gábor,

Please explain what is wrong with a two-bit (four-state) field like
this?

00: Let the hardware, firmware, or device driver decide.  (I.e., same as
    omitting Tx flags altogether.)
01: Send RTS/CTS.
10: Send CTS to self.
11: Forbid CTS-to-self and RTS/CTS.

This is just a small modification to one of your previous proposals.

(Note that I have trimmed the lengthy To: line!)

Dave

-- 
David Young             OJC Technologies
[email protected]      Urbana, IL * (217) 278-3933