Wifi Phy State during Virtual Carrier Sense

[Varun Reddy]

In the current implementation of Wifi on ns3, it seems that stations continue to listen to the channel even when the NAV counter > 0 (They remain in IDLE mode). Is this typically the case with 802.11, or should the stations actually be in sleep mode (or power save mode, where the transceiver is switched off) ?

Varun

[Rediet]

Hello Varun,

I had understood that in the normal case (that is when not in presence of power save stations that can enter in doze state when not concerned by the TXOP), STAs should continue to listen and decode incoming PPDUs. This way they can update the NAV with new PPDUs (like CTSs, or even better CF-Ends). Another argument that goes in this sense; carrier sense and reception functions are PHY level, whereas NAV is MAC level (with CS state is notified to MAC layer).

BR,

Rediet

[Varun Reddy]

Hi Rediet,

I see, your arguments are very much sensible. Could you also point me to a good reference, where I could more about such finer details in 802.11? Thanks!

Varun

[Rediet]

Eldad Perahia and Robert Stacey's book entitled "Next Generation Wireless LANs. 802.11n and 802.11ac" 2nd Edition is a very good reference.