[Ns-developers] CS mechanism

[Denis Fakhriev]

On Fri, 27 Mar 2009 08:38:06 +0100
  Mathieu Lacage <mathieu.lacage at sophia.inria.fr> wrote:
> On Thu, 2009-03-26 at 16:04 +0300, Denis Fakhriev wrote:
> 
>>   I'm doing research on the implementation of csma/cs 
>> mechanism in ns3 and I have a question about it.
>> According to IEEE 802.11 standard, station can initiate 
>> packet transmission only if Phy
>> State have been detected as IDLE. But what I've found is 
>> just comment
>> > //NS_ASSERT (m_phy->IsStateIdle ());
>> in MacLow::StartTransmission.
>> Has this rule been implemented in ns3 and if it has, 
>> please tell me where.
> 
> See dcf-manager.cc
> 
> Mathieu
> 

Hi, Mathieu.
Thank you for your help.

I've looked thorough dcf-manager.cc and I have two 
questions about it:
1. in DcfManager::IsBusy we assume that medium is busy, if 
station
     receive/transmit packet (PHY busy) or it is NAV busy. 
Does it is means that
     station can transmit not only in IDLE state, but also 
in CcaBusy state?
2. for what reason we declare variable
     accessGrantStart = GetAccessGrantStart ();
     in DcfManager::DoGrantAccess? I can't found where 
this variable is used.

   Regards,
   Denis Fakhriev, IITP RAS