Important  The Native 802.11 Wireless LAN interface is deprecated in Windows 10 and later. Please use the WLAN Device Driver Interface (WDI) instead. For more information about WDI, see WLAN Universal Windows driver model.
The DOT11_EXTSTA_SEND_CONTEXT structure defines the Native 802.11 attributes of a packet to be sent by the miniport driver operating in Extensible Station (ExtSTA) mode. For more information about this operation mode, see Extensible Station Operation Mode.


typedef struct DOT11_EXTSTA_SEND_CONTEXT {
  USHORT             usExemptionActionType;
  ULONG              uPhyId;
  ULONG              uDelayedSleepValue;
  PVOID              pvMediaSpecificInfo;
  ULONG              uSendFlags;



The type, revision, and size of the DOT11_EXTSTA_SEND_CONTEXT structure. This member is formatted as an NDIS_OBJECT_HEADER structure.

The miniport driver must set the members of Header to the following values:


This member must be set to NDIS_OBJECT_TYPE_DEFAULT.


This member must be set to DOT11_EXTSTA_SEND_CONTEXT_REVISION_1.


This member must be set to sizeof(DOT11_EXTSTA_SEND_CONTEXT).

For more information about these members, see NDIS_OBJECT_HEADER.


The type of encryption exemption for the packet. The following exemption types are defined:


The packet is not exempt from any cipher operations performed by the 802.11 station.


The packet is exempt from any cipher operations performed by the 802.11 station. The 802.11 station must transmit the packet unencrypted.


The packet is exempt from any cipher operations performed by the 802.11 station only if the station does not have a key-mapping key for the packet's destination media access control (MAC) address. For more information about key-mapping keys, see 802.11 Cipher Key Types.


The identifier (ID) of a PHY type on the 802.11 station. The 802.11 station must use the specified PHY to transmit the packet.

The value of uPhyId must be one of the following:

  • The value of an entry in the list of active PHY types defined by the msDot11ActivePhyList MIB object. The miniport driver sets this MIB object to the list of PHYs that have been activated for use over the current basic service set (BSS) network connection. For more information about the msDot11ActivePhyList MIB object, see OID_DOT11_ACTIVE_PHY_LIST.
  • The value of DOT11_PHY_ID_ANY, in which case the 802.11 station can use any PHY from the list of active PHYs defined by the msDot11ActivePhyList MIB object.
The miniport driver must fail the send request if the PHY specified by uPhyId is either not supported or has been disabled through a proprietary mechanism implemented by the independent hardware vendor (IHV). In this situation, the miniport driver sets the Status member of the NET_BUFFER_LIST structure to NDIS_STATUS_UNSUPPORTED_MEDIA and calls NdisMSendNetBufferListsComplete to complete the send request.


The time, in microseconds, before a response to the packet is expected. The uDelayedSleepValue member is only valid when all of the following are true:

  • The packet is a media access control (MAC) service data unit (MSDU) packet.
  • The 802.11 station is operating in a power save (PS) mode. In this situation, the Extensible Station (ExtSTA) msDot11PowerSavingLevel management information base (MIB) object has any value except DOT11_POWER_SAVING_NO_POWER_SAVING. For more information about the msDot11PowerSavingLevel MIB value, see OID_DOT11_POWER_MGMT_REQUEST.
The 802.11 station uses the value of uDelayedSleepValue to optimize network performance while operating in a PS mode. For example, depending upon the PS mode, the 802.11 station might keep the radio turned on after the transmission of the packet if uDelayedSleepValue is small. By doing so, the network latency will be reduced for receiving the response.


A pointer to a buffer that contains media-specific information. This member should be NULL when the 802.11 NET_BUFFER_LIST structure that this structure is associated with comes from the native 802.11 framework itself (including any NET_BUFFER_LIST structures that come from an IHV extension).

Otherwise, pvMediaSpecificInfo points to the out-of-band (OOB) data that is associated with the MediaSpecificInformation entry at the NetBufferListInfo member of the original 802.3 NET_BUFFER_LIST structure. pvMediaSpecificInfo allows the miniport driver to access the media-specific information from an IHV-specific 802.3 protocol driver.


A set of flags that define send attributes. Currently, there are no flags defined. This member should be zero.


The miniport driver performs a send operation when its MiniportSendNetBufferLists is called. Each packet passed to the driver through this function is defined by a NET_BUFFER_LIST structure, which contains Native 802.11 out-of-band (OOB) data. The OOB data contains media-specific parameters that the 802.11 station uses when transmitting the packet.

The miniport driver accesses the Native 802.11 OOB data through the NET_BUFFER_LIST_INFO macro with the following parameters:

  • The _NBL parameter, which is passed the pointer to the NET_BUFFER_LIST structure used for the received 802.11 packet.
  • The _ id parameter, which is passed the identifier (ID) value of MediaSpecificInformation.
For more information about Native 802.11 send operations, see Native 802.11 Send Operations.


Minimum supported client Available in Windows Vista and later versions of the Windows operating systems.
Header windot11.h (include Ndis.h)

See Also