power save (802.11) (PS)

Power Save(PS) is an idle state ofWLANs according to IEEE 802.11 in contrast to Active Mode( AM), the active state. The idle state of the mobile device is marked in the control frame of the MAC layer.

During this idle state, the access points( AP) temporarily store incoming messages until the mobile device retrieves them. The PS poll frame allows the mobile station( MS) to retrieve the information cached in the access point. The access point can respond immediately to a PS request or respond to the request with an acknowledgement and defer the action until later.