IP Library › Granted Patent US 10,764,900
Granted Patent B1
US 10,764,900 · App. 16/657,754 · Granted Sep 1, 2020

Method and system for opportunistic scheduling of block acknowledgement requests for locating idle clients

Inventors: Guru Gopalakrishnan (Palo Alto, CA); Hongbo Liu (Oranmore, IE)
Assignee: Cisco Technology, Inc.
H04W72/048H04W52/0216H04W64/006H04W72/0446
View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 10,764,900
App. No.
16/657,754
Granted
Sep 1, 2020
Kind
B1
Abstract

The aspects include a method or system that identifies, by an access point (AP), an idle window in a fast locate scan interval. The AP can schedule a Block Acknowledgement Request (BAR) for an idle Station (STA) in the idle window. The AP may then transmit the BAR in the idle window to the idle STA. In response to the BAR, the AP can receive a Block Acknowledgement (BA). The AP may then determine a characteristic about the BA, and, based at least on the characteristic, determine a location of the idle STA.

Claims (41)

1. A method comprising:

identifying, by an access point (AP), an idle window in a fast locate scan interval wherein the idle window is a slot reserved in a beacon interval wherein the slot is a non-Target Wake Time (TWT) slot for transmission to a non-TWT agreement established High Efficiency (HE) Station (STA);

scheduling a Block Acknowledgement Request (BAR) for an idle STA in the idle window wherein the BAR is sent to a non-HE STA in the non-TWT slot wherein two or more BARs are sent during the fast locate scan interval;

transmitting the BAR in the idle window wherein a time interval between BAR transmissions is governed by an equation where a number of non-TWT slots is multiplied by a slot time for each of the non-TWT slots then subtracting a start offset and an end offset, with a result being divided by a number of STAs to be sent a BAR;

receiving a Block Acknowledgement (BA) in response to the BAR;

determining a characteristic about the BA; and

based on the characteristic, determining a location of the idle STA.

2. The method of claim 1 , wherein BARs are transmitted to two or more STAs based on a sleep likelihood factor, and wherein a first STA with a lower sleep likelihood factor receives a first BAR transmission before a second STA with a higher sleep likelihood factor.

3. The method of claim 2 , wherein one or more BARs are burst to one or more STAs and wherein a BAR is sent as a Spatial Reuse (SR) Physical Layer Convergence Procedure (PLCP) Protocol Data Unit (PPDU) (SRP) to initiate an exchange of BAR and BA during a SRP opportunity that may arise within the fast locate scan interval.

4. The method of claim 1 , wherein the characteristic is a Received Signal Strength Indicator (RSSI), and wherein triangulation, based on the RSSI of the BA, between three or more APs determines the location of the idle STA.

5. An access point (AP) comprising:

a radio operable to:

send a Block Acknowledgement Request (BAR); and

receive a Block Acknowledgement (BA) in response to the BAR;

a memory;

a processor in communication with the memory and the radio, the processor operable to:

identify an idle window in a fast locate scan interval;

schedule the BAR for an idle Station (STA) in the idle window;

transmit the BAR in the idle window wherein two or more BARs are sent during the fast locate scan interval, wherein the two or more BARs are distributed during the fast locate scan interval, and wherein a time interval between BAR transmissions is governed by an equation where a number of non-Target Wake Time (TWT) slots is multiplied by a slot time for each of the non-TWT slots then subtracting a start offset and an end offset, with a result being divided by a number of STAs to be sent a BAR;

receive the BA in response to the BAR;

determine a characteristic about the BA; and

based on the characteristic, determining a location of the idle STA.

6. The AP of claim 5 , wherein the idle window is a slot reserved in a beacon interval, wherein the slot is a non-TWT slot for transmission to a non TWT agreement established High Efficiency (HE) STA, and wherein the BAR is sent to a non-HE STA in the non-TWT slot.

7. The AP of claim 5 , wherein BARs are transmitted to two or more STAs based on a sleep likelihood factor, and wherein a first STA with a lower sleep likelihood factor receives a first BAR transmission before a second STA with a higher sleep likelihood factor.

8. The AP of claim 5 , wherein the characteristic is a Received Signal Strength Indicator (RSSI), and wherein triangulation, based on the RSSI of the BA, between three or more APs determines the location of the idle STA.

9. A network comprising:

a first Access Point (AP) operable to:

identify an idle window in a fast locate scan interval;

schedule a Block Acknowledgement Request (BAR) for an idle Station (STA) in the idle window;

transmit the BAR in the idle window wherein two or more BARs are sent during the fast locate scan interval wherein the two or more BARs are distributed during the fast locate scan interval, and wherein a time interval between BAR transmissions is governed by an equation where a number of non-TWT slots is multiplied by a slot time for each of the non-TWT slots then subtracting a start offset and an end offset, with a result being divided by a number of STAs to be sent a BAR;

receive a Block Acknowledgement (BA) in response to the BAR;

determine a first characteristic about the BA;

receive a second characteristic about the BA from a second AP; and

based on the first characteristic and the second characteristic, determining a location of the idle STA;

the second AP operable to:

receive the BA;

determine the second characteristic about the BA; and

send the second characteristic to the first AP.

10. The network of claim 9 , wherein the idle window is a slot reserved in a beacon interval, wherein the slot is a non-TWT slot for transmission to a non TWT agreement established High Efficiency (HE) STA, and wherein the BAR is sent to a non-HE STA in the non-TWT slot.

11. The network of claim 9 , wherein BARs are transmitted to two or more STAs based on a sleep likelihood factor, and wherein a first STA with a lower sleep likelihood factor receives a first BAR transmission before a second STA with a higher sleep likelihood factor.

12. The network of claim 11 , wherein the characteristic is a Received Signal Strength Indicator (RSSI), and wherein triangulation, based on the RSSI of the BA, between three or more APs determines the location of the idle STA.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Oct 18, 2019
From: GOPALAKRISHNAN, GURU; LIU, HONGBO
To: CISCO TECHNOLOGY, INC.
Reel/Frame 050764/0717 →
Cited By (6)
US 12,267,784 US 12,376,042 US 12,471,052 US 12,532,271 US 12,563,506 US 12,701,500