[Ns-developers] 802.11 10Mhz Channel

[Basim Javed]

hi all

CwMin parameter has to do nothing with DcaTxop. In QoS enabled MAC, each
queue handles its own DcaTxop independently.

regards
B

On Thu, Jul 16, 2009 at 11:23 PM, Pei, Guangyu <Guangyu.Pei at boeing.com>wrote:

> It seems to me that CwMin parameter is controlled by DcaTxop. Each MAC
> handles its own DcaTxop.  Should we add a virtual function SetCwMin may
> be added in WifiMac class? For non-QoS MACs, it seems that each mac has
> only one DcaTxop and it is straightforward to add one. For QoS  MAC, it
> seems that only beacon Dca needs to be set. Does this sound ok?
>
> Gary
>
>
> > -----Original Message-----
> > From: Nicola Baldo [mailto:nbaldo at cttc.es]
> > Sent: Thursday, July 16, 2009 9:03 AM
> > To: ns-developers
> > Subject: Re: [Ns-developers] 802.11 10Mhz Channel
> >
> > Also CwMin should be set to 31 (instead of 15) when using 802.11b.
> > See IEEE Std. 802.11-2007, section 15.3.3 "DS PHY characteristics".
> >
> > Nicola
> >
> > Pei, Guangyu wrote:
> > > Hi,
> > >
> > > I double-checked the standard. I believe the following
> > settings are correct.
> > >
> > > +WifiMac::Configure80211b (void)
> > > +{
> > > +  SetSifs(MicroSeconds(10));
> > > +  SetSlot(MicroSeconds(20));
> > > +  SetEifsNoDifs(MicroSeconds(10+304));
> > > +  SetPifs(MicroSeconds(10+20));
> > > +
> > >
> > +SetCtsTimeout(MicroSeconds(10+304+20+GetDefaultMaxPropagationDelay().
> > > +GetMicroSeconds ()*2));
> > > +
> > >
> > +SetAckTimeout(MicroSeconds(10+304+20+GetDefaultMaxPropagationDelay().
> > > +GetMicroSeconds ()*2)); }
> > >
> > > In particular, I believe 304 is the Ack Tx time = AckSize + PLCP
> > > Preamble + PCLP Header = 8*14 + 144 + 48 = 304
> > >
> > > Thanks,
> > >
> > > Gary
> > >
> > >> -----Original Message-----
> > >> From: Ramon Bauza [mailto:monbauza at gmail.com]
> > >> Sent: Monday, July 13, 2009 3:22 AM
> > >> To: Mathieu Lacage
> > >> Cc: ns-developers at ISI.EDU
> > >> Subject: Re: [Ns-developers] 802.11 10Mhz Channel
> > >>
> > >> Hi,
> > >>
> > >> Thank you for your comments. Please find the new patch modified
> > >> accordingly to your suggestions. Now, WifiMacHelpers
> > remain the same
> > >> way as in ns-3-dev.
> > >> I have also added the Configure80211b method to configure MAC
> > >> parameters.
> > >> However, I would like someone to review the parameters, since I am
> > >> not very familiar with the 802.11b specification.  As Std
> > 802.11-2007
> > >> states (page 654), I have considered:
> > >>
> > >> - SlotTime = 20us
> > >> - SIFS = 10us
> > >>
> > >> Ramon.
> > >>
> >
>
>