Why macAckWaitDuration @unit(s) = 0.00056 s in the CSMA802154.ned

[Norberto - IT]

Why the:

macAckWaitDuration @unit(s) = 0.00056 s;  // 1+12+10+12 symbols

 

Instead of macAckWaitDuration @unit(s) = 0.000864 s;  // 20+12+10+12 symbols, as defined in the standard

 

 

 

[LuisTH]

Hi,

I did not design the module, but I agree with you: the value should be 864us. I would set this default in my implementation.
I would be helpful also to add the MiXiM version you refer to, which I assume is v2.1.  In v2.2.1 the  macAckWaitDuration is set only in the base ned file "csma.ned".

BR,
Luis.

[Daniel Pfefferkorn]

Please do not as it would not be consistent with the standard.

Please see the full discussion on this toppic:
http://groups.google.com/group/omnetpp/browse_thread/thread/ab4860b2756f2742/5a283c167558dd84?lnk=gst&q=macackwaitduration#5a283c167558dd84

To cite Laura:

"

Am 07.02.2012 20:08, schrieb Laura Marie Feeney:
> Hi Daniel and Noberto,
>
> Thanks for the careful discussion!
>
> However, this analysis is not correct for the CSMA802154Narrow, which
> models the nonbeacon-enabled PAN.
>
> Your formula, from section 7.4.2 of the specification, applies to
> beacon-enabled PAN -- in that case, the receiver must wait until the
> next slot boundary (ie up to aUnitBackoff) before transmitting the ACK.
>
> In the non-beacon-enabled case, the receiver responds at aTurnaroundTime
> (i.e. the time for the sender and receiver to both be guaranteed to have
> switched from Tx to Rx and vice verse). This gives the value 192us +
> 352us = 544us (there's been some discussion about the "extra" 1 symbol
> == 16us). Note also that in practice, the comparison should take into
> account timing inaccuracy in the simulation.
>
> This also is made clear in section 7.5.6.4.2 of the specification. You
> may also want to look at the analysis and experiment in e.g. Latre et al
> 2006.
>
> Laura
"

> --
> Sent from the OMNeT++ mailing list. To configure your membership,
> visit http://groups.google.com/group/omnetpp

--
M.Sc. Daniel Pfefferkorn

Institute of Microelectronic Systems

Leibniz University Hannover phone: +49 (511) 762 - 19609
Appelstr. 4 fax: +49 (511) 762 - 19601
30167 Hannover e-mail: pfef...@ims.uni-hannover.de
Germany

[LuisTH]

Thanks, I will follow the discussion on the link you gave.

BR,
Luis