IEEE P802.11
Wireless LANs

802.11 [Ranging Availability Window Negotiation] (relative to IEEE 802.11 REVmd D1.0 and 802.11az D0.3)
Date: 2018-07-12
Author(s):
Name	Company	Address	Phone	Email
Dibakar Das	Intel	Dibakar.das@intel.com
Chittabrata Ghosh	Intel	Chittabrata.Ghosh@intel.com
Segev, Jonathan	Intel	Jonathan.segev@intel.com
Ganesh Venkatesan	Intel Corporation	2111 NE 25th Ave, Hillsboro, OR 97124	503 334 6720	ganesh.venkatesan@intel.com

Abstract This submission is amendment text corresponding to the Ranging Availability Window Negotiation described in document 18-1138r1. History: R0: Initial Version

TGaz Editor: Insert the following new rows into Table 9-77 (Element IDs) (header row shown for convenience):

Table 9-77 -- Element IDs

Element	Element ID	Element ID Extension	Extensible	Fragmentable
Ranging Availability Window	255	<ANA>	Yes	No
Ranging Unavailability	255	<ANA>	Yes	No

TGaz Editor: Insert the following new clauses to Cl. 9.4.2 (Elements):

9.4.2.x Ranging Availability Window

The Ranging Availability Window element describes a time window during which the RSTA is expected to execute the HEz Range Measurement exchange with a set of ISTAs (See 11.22.6.4.2 (Measurement Exchange in HEz Mode)). The format of the Ranging Availability Window element is shown in Figure 9-x (Ranging Availability Window element format).

Element ID (255)	Length (4n+2)	Extended Element ID	Count	Availability Window-1	…	Availability Window-n
Octets	1	1	1	1	4	…	4

Figure 9-x Ranging Availabiltiy Window element format

The Element ID, Length and Extended Element ID fields are defined in 9.4.2.1 (General)

The count field indicates the number of Availability Window fields.

The Availability Window field describes an availability window. The format of the Availability Window field is shown in Figure 9-y Availability Window field format.

Partial TSF Timer	Duration	Reserved	Periodicity
Bits	16	6	2	8

Figure 9-y Availability Window field format

The Partial TSF Timer subfield is the same as defined in 9.4.2.166 (Fine Timing Measurement Parameters element).

The Duration subfield describes the duration of the availability window in 100 usec units. The valid range for Duration subfield is 1 through 64 (100 usec to 6.4 msec).

The Periodicity subfield describes the period for the occurrence of the availability window in units of 100 msec. The valid range for the Periodicity subfield is 1 through 255 (100 msec to 25.5 seconds).

9.4.2.y Ranging Unavailability

The Ranging Unavailability element describes the unavailability or availability of an ISTA in order to execute the HEz Range Measurement Exchange (See 11.22.6.4.3 Measurement Exchange in HEz Mode). The format of the Ranging Unavailability element is shown in Figure 9-z (Ranging Unavailability element format).

Element ID	Length	Extended Element ID	Count	Reserved	Unavailability	…	Unavailability
Bits	8	8	8	9	7	1	…	1

Figure 9-z Ranging Unavailability element format

The Element ID, Length and Extended Element ID fields are defined in 9.4.2.1 (General)

The count field is 9 bits wide and indicates the number of UnAvailability fields. The valid range of values for the count field is 1 through 512.

The Unavailability fields are each 1 bit wide. The Unavailability field when set to 1 indicates that the STA is unavailable and when set to 0 indicates that the STA is available, for executing the HEz range measurement exchange.

TGaz Editor: Note that the HEz Specific subelement description below is new and is part of submission 18-788r5. Modify the description of the HEz Specific Parameters subelement in Cl. 9.4.2.246 (Ranging Parameters) as follows:

9.4.2.246 Ranging Parameters

The format of the HEz Specific subelement is as shown in Figure 9-610d (HEz Specific subelement format)

Subelement ID (1)	Length	Ranging ID	Response	Reserved	MaxToAAvailableExp (#Ed)	BSS Color	Ranging Availability Window/Ranging Unavailability
Octets	8	8	16	1	3	4	8	Variable

Figure 9-610d HEz Specific subelement format

The Element ID and Length fields are defined in 9.4.3 (Subelements).

The Ranging ID is the same as the AID if the initiator is associated with the responder; and is similar to AID and is assigned by the responder to identify the unassociated initiator. The Ranging ID and the AID are derived the same space and are non-conflicting. This field is reserved when the corresponding HEz Specific subelement is contained in the Ranging Parameters element within an initial Fine Timing Measurement Request frame.

The Response field is either set to 0 or 1, indicating Immediate or Delayed response. If the Response field is set to Immediate then the ToD andToA values included in the corresponding Location Measurement Report (LMR) frame are from the current range measurement; and if the Response field is set to Delayed then the ToD and ToA values in the corresponding LMR frame are from the previous range measurement. This field is reserved when the corresponding HEz Specific subelement is contained in the Ranging Parameters element within an initial Fine Timing Measurement Request frame.

The MaxToAAvailableExp field is the same as described under VHTz Specific subelement. This field is reserved when the corresponding HEz Specific subelement is contained in the Ranging Parameters element within an initial Fine Timing Measurement Request frame.

The BSS Color field is an unsigned integer in the range 1 to 63 whose value is set to the same BSS Color value contained in the HE Operation element that an RSTA transmit.

The Ranging Availability Window/Ranging Unavailability field is a Ranging Unavailability element (9.4.2.y Ranging Unavailability element) in a HEz Specific element when the corresponding HEz Specific subelement is contained in the Ranging Parameters element within an initial Fine Timing Measurement Request frame. The Ranging Availability Window/Ranging Unavailability field is a Ranging Availability Window element (9.4.2.x Ranging Availability element) in a HEz Specific element when the corresponding HEz Specific subelement is contained in the Ranging Parameters element within an initial Fine Timing Measurement frame.

11.22.6.3 Fine timing measurement procedure negotiation

Insert a new subsection heading as follows:

11.22.6.3.1 Range Measurement Negotiation

Change the 3rd and 4th paragraphs as follows:

The initial Fine Timing Measurement Request frame shall have:

— the Trigger field set to 1,

— a set of scheduling parameters in a Fine Timing Measurement Parameters element or a set of range measurement parameters in a Ranging Parameters element that describe the initiating STA’s availability for measurement exchange.

The first Fine Timing Measurement frame in the FTM session is called the initial Fine Timing Measurement frame. The responding STA should transmit an initial Fine Timing Measurement frame within 10 ms in response to the initial Fine Timing Measurement Request frame. This initial Fine Timing Measurement frame shall include the Fine Timing Measurement Parameters element or a Ranging Parameters element. If a Ranging Parameters element is included in the initial Fine Timing Measurement frame, it shall contain one of the VHTz Specific subelement or the HEz Specific subelement.

Insert a new paragraph before the start of the 8th paragraph as follows:

If the initial Fine Timing Measurement Request includes a Ranging Parameters element in which a HEz Specific subelement is included then the initiating STA shall indicate its availability/unavailability to execute the HEz ranging procedure (11.24.6.2 Measurement Exchange in HEz Mode) by including the Ranging Unavailability element in the HEz Specific subelement.

If the request was successful

Insert the following before the last paragraph of Cl. 11.22.6.3.1

If the Request was successful and the responding STA includes a Ranging Parameters element with a HEz Specific subelement in the corresponding initial Fine Timing Measurement frame, it shall include a Ranging Availability Window that describes the ranging availability window assigned to the initiating STA by the responding STA in order to execute the HEz ranging procedure (11.24.6.2 Measurement Exchange in HEz Mode).