802.11 power mode question

Posted on 2006-04-08
Last Modified: 2013-12-09
Hi all,
Every body can explain me or redirect for information about power mode behavior?
Specifically, what happens between the NIC and Access Point(AP) when I change the power mode to Ndis802_11PowerModeMAX_PSP.

Really, I am want to notify AP that the NIC is sleeping, so the AP will not send nothig to NIC before it notified that NIC is wake. But I need that NIC is not sleeping this time.

Also, any information about which hardware independent "commands" I can ask the NIC to do that is not NDIS requests is interesting also.
Question by:Aviram_Sobol
    LVL 4

    Expert Comment


    "Ndis802_11PowerModeMAX_PSP specifies the maximum power saving for the 802.11 NIC radio. OID_802_11_POWER_MODE requests that the miniport driver set the power mode of the 802.11 NIC to this value."

    Don't understand the question. Could you be a bit more precise?
    LVL 1

    Author Comment

    Thanks, it is not what I need yet, but I will try to explain myself again.
    I try to find an information about behavior between STAtion to Access Point.
    After you assign Ndis802_11PowerModeMAX_PSP to NIC, what happen after such assignation?
    The STA notify AP immidiatelly after assignation about this mode and from this point AP send packets to STA only on demand?
    Or the NIC go sleep in some period and notify AP each time about going to sleep?
    LVL 4

    Accepted Solution

    Ok. Here is a link you may find of interest. It refers to an 802.11g rt2570 USB driver source code:

    After reading through the code I found a possible answer for your question. In the PeerBeacon function (executed when a beacon is received from peer) it looks like it performs a number of steps to act when the Infrastructure mode is on and then PowerMode flag is set to PWR_SAVE. This is what they do:

    1. AP has backlogged unicast-to-me frame, stay AWAKE, send PSPOLL
    2. AP has backlogged broadcast/multicast frame and we want those frames, stay AWAKE
    3. we have outgoing frames in TxRing or PrioRing, better stay AWAKE
    4. Psm change to PWR_SAVE, but AP not been informed yet, we better stay AWAKE
    5. otherwise, put PHY back to sleep to save battery.

    It seems to keep connected to the AP until all outstanding frames has been sent out and the AP is informed that we go to sleep. Then it turns the power down to save battery.
    LVL 1

    Author Comment

    Thanks, opanza.

    Moderators\Administrators, please don't close this topic yet, I will back later to this question. (This time I haven't time to continue deal with it)

    Featured Post

    What Is Threat Intelligence?

    Threat intelligence is often discussed, but rarely understood. Starting with a precise definition, along with clear business goals, is essential.

    Join & Write a Comment

    With Windows Embedded Handheld, called Windows Mobile, Microsoft re-designed the user interface. The Start Icon moved down to the bottom, inside the menu bar area.   If you need to hide the Start Icon and/or the SIP (soft input panel, softwar…
    In this article we will discuss all things related to StageFright bug, the most vulnerable bug of android devices.
    Sending a Secure fax is easy with eFax Corporate ( First, Just open a new email message.  In the To field, type your recipient's fax number You can even send a secure international fax — just include t…
    Internet Business Fax to Email Made Easy - With eFax Corporate (, you'll receive a dedicated online fax number, which is used the same way as a typical analog fax number. You'll receive secure faxes in your email, fr…

    728 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    21 Experts available now in Live!

    Get 1:1 Help Now