TWT Setup Command and Flow Type description

The TWT Setup Command which is part of the TWT parameter set field as shown below can take the below command values

FIG Courtesy: 802.11ax Standard
TWT Setup Command ValueTWT Setup Command NameCommand Description
0Request TWTA TWT requesting or TWT scheduled STA requests to join a TWT without specifying a target wake time.

This command is valid if the TWT Request field is equal to 1; otherwise, the command is not applicable.
1Suggest TWTA TWT requesting or TWT scheduled STA requests to join a TWT and specifies a suggested set of TWT parameters with the possibility that if the requested target wake time and/or other TWT parameters cannot be accommodated, then the TWT setup might still be accepted by the TWT requesting or TWT scheduled STA.

This command is valid if the TWT Request field is equal to 1; otherwise, it is not applicable.
2Demand TWTA TWT requesting or TWT scheduled STA requests to join a TWT and specifies a demanded set of TWT parameters. If the demanded set of TWT parameters is not accommodated by the responding STA or TWT scheduling AP, then the TWT requesting STA or TWT scheduled STA will reject the TWT setup.

This command is valid if the TWT Request field is equal to 1; otherwise, it is not applicable.
3TWT GroupingThe TWT responding STA suggests TWT group parameters that are different from the suggested or demanded TWT parameters of the TWT requesting STA

This command is valid if the TWT Request field is 0 and the Negotiation Type subfield is 0 and sent by an S1G STA; otherwise, it is not applicable.
4Accept TWTA TWT responding STA or TWT scheduling AP accepts the TWT request with the TWT parameters (see NOTE) indicated in the TWT element transmitted by the TWT requesting STA or TWT scheduled STA. This value is also used in unsolicited TWT responses.

This command is valid if the TWT Request field is 0; otherwise, it is not applicable.
5Alternate TWTA TWT responding STA or TWT scheduling AP suggests TWT parameters that are different from those suggested by the TWT requesting STA or TWT scheduled STA.

This command is valid if the TWT Request field is 0; otherwise, it is not applicable.
6Dictate TWTA TWT responding STA or TWT scheduling AP indicates TWT parameters that are different from those suggested by the TWT requesting STA or TWT scheduled STA.

This command is valid if the TWT Request field is 0; otherwise, it is not applicable.
7Reject TWTA TWT responding STA or TWT scheduling AP rejects setup, or a TWT scheduling AP terminates an existing broadcast TWT, or a TWT scheduled STA terminates its membership in a broadcast TWT.

The Flow Type subfield shown below determines whether a TWT Service Period will be an “Announced TWT” or an “UnAnnounced TWT“.

Fig Courtesy: 802.11ax Standard
Flow Type ValueDescription
0Announced TWT and Announced TWT SP.

TWT requesting STA or TWT scheduled STA will send a PS-Poll or an APSD trigger frame to signal its awake state to the TWT responding STA or TWT scheduling AP before a frame that is not a Trigger frame is sent from the TWT responding STA or TWT scheduling AP to the TWT requesting STA or TWT scheduled STA
1Unannounced TWT and Unannounced TWT SP

TWT responding STA or TWT scheduling AP will send a frame to the TWT requesting STA or TWT scheduled STA at TWT without waiting to receive a PS-Poll or an APSD trigger frame from the TWT requesting STA or TWT scheduled STA

The TWT Flow Identifier subfield contains a 3-bit value that :

  1. identifies the specific information for this TWT request uniquely from other requests made between the same TWT requesting STA and TWT
    responding STA pair

Example operation for Individual TWT and Broadcast TWT

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