[Ns-developers] 802.11 10Mhz Channel

[Pei, Guangyu]

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.
> >>
>