ENHANCED RTS/CTS ENABLEMENT AND DETECTION

• US 20160081106A1
• Filed: 09/11/2015
• Published: 03/17/2016
• Est. Priority Date: 09/15/2014
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Merlin, Simone, Cherian, George, Zhou, Yan, Barriac, Gwendolyn Denise
• Granted Patent: US 9,838,900 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 28/26 Resource reservation
• CPC Class Codes: H04W 74/00 Wireless channel access
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be an AP that requests a plurality of STAs to jointly enable and disable an MRP based on at least one of that each STA of the STAs has uplink traffic with the AP or that each STA of a subset of the STAs has a hidden node. The AP receives, from the STAs, information indicating a communication metric while jointly enabling or disabling the MRP. The AP determines, based on the received information indicating the communication metric, whether the joint enablement of the medium reserving procedure improves communication for the plurality of STAs. The AP requests the STAs to jointly enable the medium reserving procedure for subsequent communication when the joint enablement of the medium reserving procedure improves communication for the plurality of STAs.

Claims

1. A method of wireless communication of an access point (AP), comprising:

requesting a plurality of stations (STAs) to jointly enable and disable a medium reserving procedure based on at least one of that each STA of the plurality of STAs has uplink traffic with the AP or that each STA of a subset of STAs of the plurality of STAs has a hidden node that transmits data to the AP and disrupts a communication between the AP and the each STA, the medium reserving procedure reserving a medium for data transmission;

receiving, from the plurality of STAs, information indicating a communication metric while jointly enabling or disabling the medium reserving procedure;

determining, based on the received information indicating the communication metric, whether the joint enablement of the medium reserving procedure improves communication for the plurality of STAs; and

requesting the plurality of STAs to jointly enable the medium reserving procedure for subsequent communication when the joint enablement of the medium reserving procedure improves communication for the plurality of STAs.

2. The method of claim 1, further comprising determining that each of the plurality of STAs has a hidden node, wherein the plurality of STAs are requested to jointly enable and disable the medium reserving procedure based on the AP receiving interference from the hidden node in association with the plurality of STAs.

3. The method of claim 1, further comprising determining that each STA of the subset of STAs has a hidden node that causes interference to the AP, wherein the plurality of STAs are requested to jointly enable and disable the medium reserving procedure based on that the plurality of STAs each have uplink traffic and that a ratio of the subset of STAs with respect to the plurality of STAs meets a threshold.

4. The method of claim 1, wherein the medium reserving procedure employs a Request-to-Send (RTS)/Clear-to-Send (CTS) procedure.

5. The method of claim 1, wherein the communication metric includes at least one of an actual throughput, an equivalent full buffer throughput, a retry rate, a packet error rate (PER), a modulation coding scheme (MCS), or an access delay.

6. The method of claim 1, wherein the requesting the plurality of STAs to jointly enable and disable the medium reserving procedure includes:

requesting the plurality of STAs to jointly enable the medium reserving procedure in a first time period and to jointly disable the medium reserving procedure in a second time period; and

wherein the determining whether the joint enablement of the medium reserving procedure improves communication includes;

determining the communication metric of the plurality of STAs in the first time period and the communication metric of the plurality of STAs in the second time period; and

determining an improvement of the communication metric in the first time period comparing with the communication metric in the second time period, and wherein the communication for the plurality of STAs is determined to be improved when the improvement of the communication metric meets a first threshold.

7. The method of claim 6, wherein the determining the communication metric of the plurality of STAs in the first time period and the communication metric of the plurality of STAs in the second time period includes:

receiving data from each STA of the plurality of STAs with joint enablement of the medium reserving procedure in the first time period;

determining a respective first value of the communication metric for each STA of the plurality of STAs based on the data received from the each STA in the first time period;

receiving data from each STA of the plurality of STAs with joint disablement of the medium reserving procedure in the second time period; and

determining a respective second value of the communication metric for each STA of the plurality of STAs based on the data received from the each STA in the second time period, wherein the improvement of the communication metric is determined based on the first values and the second values.

8. The method of claim 6, wherein the requesting the plurality of STAs to jointly enable the medium reserving procedure in the first time period and to jointly disable the medium reserving procedure in the second time period comprising:

transmitting, to the plurality of STAs, a first time indicator indicating the first time period; and

transmitting, to the plurality of STAs, a second time indicator indicating the second time period.

9. The method of claim 6, wherein the requesting the plurality of STAs to jointly enable the medium reserving procedure in the first time period and to jointly disable the medium reserving procedure in the second time period comprising:

transmitting, to the plurality of STAs, a STA indicator identifying the each STA of the plurality of STAs.

10. The method of claim 9, wherein the STA indicator is included in an information element (IE) of a frame or is an information bit in a frame.

11. The method of claim 1, further comprising determining that a first STA of the subset of STAs has a hidden node when the AP detects a change of a signal metric during reception a data packet received from the first STA.

12. The method of claim 11, further comprising:

receiving the data packet from the first STA;

determining a first value of the signal metric at a first position of the data packet; and

determining a second value of the signal metric at a second position of the data packet, wherein the change of the signal metric is detected based on the first value and the second value.

13. The method of claim 11, wherein the signal metric includes at least one of a received signal strength indication (RSSI), an estimated channel coefficient, an estimated phase offset, an estimated frequency offset, or a measured pilot error vector magnitude.

14. The method of claim 1, further comprising determining that a first STA of the subset of STAs has a hidden node when the AP detects that one or more data units in a data packet from the first STA have not been correctly received at the AP.

15. The method of claim 1, further comprising determining that a first STA of the subset of STAs has a hidden node when the AP detects a difference between an estimated packet error rate (PER) and a measured PER for packets received from the first STA.

16. The method of claim 1, further comprising determining that a first STA of the subset of STAs has a hidden node when the AP receives a report from the first STA, wherein the report includes an identification of the hidden node of the first STA.

17. An apparatus for wireless communication, the apparatus being an access point (AP), comprising:

a memory; and

at least one processor coupled to the memory and configured to;

request a plurality of stations (STAs) to jointly enable and disable a medium reserving procedure based on at least one of that each STA of the plurality of STAs has uplink traffic with the AP or that each STA of a subset of STAs of the plurality of STAs has a hidden node that transmits data to the AP and disrupts a communication between the AP and the each STA, the medium reserving procedure reserving a medium for data transmission;

receive, from the plurality of STAs, information indicating a communication metric while jointly enabling or disabling the medium reserving procedure;

determine, based on the received information indicating the communication metric, whether the joint enablement of the medium reserving procedure improves communication for the plurality of STAs; and

request the plurality of STAs to jointly enable the medium reserving procedure for subsequent communication when the joint enablement of the medium reserving procedure improves communication for the plurality of STAs.

18. The apparatus of claim 17, wherein the at least one processor is further configured to determine that each of the plurality of STAs has a hidden node, wherein the plurality of STAs are requested to jointly enable and disable the medium reserving procedure based on the AP receiving interference from the hidden node in association with the plurality of STAs.

19. The apparatus of claim 17, wherein the at least one processor is further configured to determine that each STA of the subset of STAs has a hidden node that causes interference to the AP, wherein the plurality of STAs are requested to jointly enable and disable the medium reserving procedure based on that the plurality of STAs each have uplink traffic and that a ratio of the subset of STAs with respect to the plurality of STAs meets a threshold.

20. The apparatus of claim 17, wherein the medium reserving procedure employs a Request-to-Send (RTS)/Clear-to-Send (CTS) procedure.

21. The apparatus of claim 17, wherein the communication metric includes at least one of an actual throughput, an equivalent full buffer throughput, a retry rate, a packet error rate (PER), a modulation coding scheme (MCS), or an access delay.

22. The apparatus of claim 17, wherein to request the plurality of STAs to jointly enable and disable the medium reserving procedure, the at least one processor is further configured to:

request the plurality of STAs to jointly enable the medium reserving procedure in a first time period and to jointly disable the medium reserving procedure in a second time period; and

wherein to determine whether the joint enablement of the medium reserving procedure improves communication, the at least one processor is further configured to;

determine the communication metric of the plurality of STAs in the first time period and the communication metric of the plurality of STAs in the second time period; and

determine an improvement of the communication metric in the first time period comparing with the communication metric in the second time period, and wherein the communication for the plurality of STAs is determined to be improved when the improvement of the communication metric meets a first threshold.

23. The apparatus of claim 22, wherein to determine the communication metric of the plurality of STAs in the first time period and the communication metric of the plurality of STAs in the second time period, the at least one processor is further configured to:

receive data from each STA of the plurality of STAs with joint enablement of the medium reserving procedure in the first time period;

determine a respective first value of the communication metric for each STA of the plurality of STAs based on the data received from the each STA in the first time period;

receive data from each STA of the plurality of STAs with joint disablement of the medium reserving procedure in the second time period; and

determine a respective second value of the communication metric for each STA of the plurality of STAs based on the data received from the each STA in the second time period, wherein the improvement of the communication metric is determined based on the first values and the second values.

24. A method of wireless communication of a first station (STA), comprising:

sending, in accordance with a Request-to-Send (RTS)/Clear-to-Send (CTS) procedure, one or more RTS messages to a second STA;

receiving zero or more CTS messages in response to the RTS messages from the second STA;

determining a response rate based on the RTS messages and the CTS messages; and

sending a first request to the second STA when the response rate meets a first threshold, the first request requesting the second STA to announce receiver availability for receiving data transmission.

25. The method of claim 24, wherein the first request includes a channel load at the first STA.

26. The method of claim 24, wherein the one or more RTS messages include a first number of RTS messages, wherein the zero or more CTS messages include a second number of CTS messages, and wherein the response rate is determined based on the first number and the second number.

27. The method of claim 24, further comprising:

receiving, from the second STA, a first confirmation indicating that the second STA implements a polling procedure;

receiving a polling message in accordance with the polling procedure, wherein the polling message indicates that the second STA is available for data transmission; and

transmitting data to the second STA in response to the polling message.

28. The method of claim 27, further comprising:

receiving, from the second STA, a second request requesting the first STA to implement the RTS/CTS procedure, wherein the second request includes a channel load at the second STA;

determining that a difference between the channel load at the second STA and a channel load at the first STA meets a second threshold; and

transmitting, to the second STA, a second confirmation indicating that the first STA implements the RTS/CTS procedure.

29. An apparatus for wireless communication, the apparatus being a first station (STA), comprising:

a memory; and

at least one processor coupled to the memory and configured to;

send, in accordance with a Request-to-Send (RTS)/Clear-to-Send (CTS) procedure, one or more RTS messages to a second STA;

receive zero or more CTS messages in response to the RTS messages from the second STA;

determine a response rate based on the RTS messages and the CTS messages; and

send a first request to the second STA when the response rate meets a first threshold, the first request requesting the second STA to announce receiver availability for receiving data transmission.

30. The apparatus of claim 29, wherein the at least one processor is further configured to:

receive, from the second STA, a first confirmation indicating that the second STA implements a polling procedure;

receive a polling message in accordance with the polling procedure, wherein the polling message indicates that the second STA is available for data transmission; and

transmit data to the second STA in response to the polling message.