METHOD AND APPARATUS FOR COMMUNICATING WITH EXTENDED RANGE IN A WIRELESS NETWORK

• US 20130208607A1
• Filed: 08/17/2012
• Published: 08/15/2013
• Est. Priority Date: 08/20/2011
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Abraham, Santosh Paul, Merlin, Simone, Wentink, Maarten Menzo, Van Nee, Didier Johannes Richard
• Granted Patent: US 9,326,158 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 24/08 Testing, supervising or monitoring using real traffic
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

Techniques for supporting communication over an extended range in a wireless network are disclosed. In one aspect, a station sends multiple messages of a given type for different operating modes. These messages can be detected by stations with different capabilities, which may avoid collisions between stations. In one design, a first station receives a Request-to-Send (RTS) message from a second station having data to send. The first station sends a first Clear-to-Send (CTS) message and also a second CTS message in response to the RTS message. The second CTS message has an extended range as compared to the first CTS message. The first station thereafter (i) receives data sent by the second station in response to the second CTS message and (ii) sends an acknowledgement having an extended range.

Claims

1. A method for wireless communication, comprising:

receiving a Request-to-Send (RTS) message;

sending a first Clear-to-Send (CTS) message in response to the RTS message;

sending a second CTS message following the first CTS message, the second CTS message having an extended range as compared to the first CTS message;

receiving data sent in response to the second CTS message; and

sending acknowledgement (ACK) having an extended range for the received data.

2. The method of claim 1, wherein the first CTS message is intended for stations not supporting an extended range mode, and wherein the second CTS message is intended for a station sending the RTS message and stations supporting the extended range mode.

3. The method of claim 2, wherein the RTS message is for the extended range mode.

4. The method of claim 1, wherein the first CTS message comprises a first preamble of a first length, and wherein the second CTS message comprises a second preamble of a second length longer than the first length.

5. The method of claim 4, wherein the second preamble comprises multiple repetitions of at least one training field in the first preamble.

6. An apparatus for wireless communication, comprising:

at least one processor configured to;

receive a Request-to-Send (RTS) message;

send a first Clear-to-Send (CTS) message in response to the RTS message;

send a second CTS message following the first CTS message, the second CTS message having an extended range as compared to the first CTS message;

receive data sent in response to the second CTS message; and

send acknowledgement (ACK) having an extended range for the received data.

7. The apparatus of claim 6, wherein the first CTS message comprises a first preamble of a first length, and wherein the second CTS message comprises a second preamble of a second length longer than the first length.

8. The apparatus of claim 7, wherein the second preamble comprises multiple repetitions of at least one training field in the first preamble.

9. An apparatus for wireless communication, comprising:

means for receiving a Request-to-Send (RTS) message;

means for sending a first Clear-to-Send (CTS) message in response to the RTS message;

means for sending a second CTS message following the first CTS message, the second CTS message having an extended range as compared to the first CTS message;

means for receiving data sent in response to the second CTS message; and

means for sending acknowledgement (ACK) having an extended range for the received data.

10. The apparatus of claim 9, wherein the first CTS message comprises a first preamble of a first length, and wherein the second CTS message comprises a second preamble of a second length longer than the first length.

11. The apparatus of claim 10, wherein the second preamble comprises multiple repetitions of at least one training field in the first preamble.

12. A computer program product, comprising:

a non-transitory computer-readable medium comprising;

code for causing at least one computer receive a Request-to-Send (RTS) message;

code for causing the at least one computer send a first Clear-to-Send (CTS) message in response to the RTS message;

code for causing the at least one computer send a second CTS message following the first CTS message, the second CTS message having an extended range as compared to the first CTS message;

code for causing the at least one computer to receive data sent in response to the second CTS message; and

code for causing the at least one computer to send acknowledgement (ACK) having an extended range for the received data.

13. A method for wireless communication, comprising:

receiving a Request-to-Send (RTS) message having an extended range;

sending a Clear-to-Send (CTS) message in response to the RTS message;

receiving data sent in response to the CTS message; and

sending acknowledgement (ACK) having an extended range for the received data.

14. The method of claim 13, wherein the RTS message comprises a preamble including multiple repetitions of at least one training field to obtain the extended range.

15. The method of claim 13, wherein the CTS message has an extended range.

16. An apparatus for wireless communication, comprising:

at least one processor configured to;

receive a Request-to-Send (RTS) message having an extended range;

send a Clear-to-Send (CTS) message in response to the RTS message;

receive data sent in response to the CTS message, and

send acknowledgement (ACK) having an extended range for the received data.

17. The apparatus of claim 16, wherein the RTS message comprises a preamble including multiple repetitions of at least one training field to obtain the extended range.

18. A method for wireless communication, comprising:

making energy measurements of a wireless medium during a backoff procedure, each energy measurement being made over a measurement period covering multiple time slots; and

determining whether the wireless medium is clear or busy in each measurement period during the backoff procedure based on an energy measurement for the measurement period.

19. The method of claim 18, further comprising:

determine whether to continue or suspend the backoff procedure in each measurement period based on a determination of whether the wireless medium is clear of busy during the measurement period.

20. The method of claim 18, further comprising:

detecting the wireless medium to be busy in a measurement period;

suspending the backoff procedure in response to detecting the wireless medium to be busy in the measurement period; and

resuming the backoff procedure after detecting the wireless medium to be clear for an extended distributed coordination function (DCF) interframe space (DIFS), the extended DIFS being for an extended range mode and being longer than a DIFS for a non-extended range mode.

21. The method of claim 18, further comprising:

determining the wireless medium to be clear for an extended distributed coordination function (DCF) interframe space (DIFS) prior to performing the backoff procedure, the extended DIFS being for an extended range mode and being longer than a DIFS for a non-extended range mode.

22. The method of claim 20, wherein the extended DIFS has a duration determined based on a length of a preamble of a message in the extended range mode.

23. The method of claim 18, further comprising:

detecting a message transmitted via the wireless medium; and

waiting for the wireless medium to be clear for an extended interframe space (EIFS) for an extended range mode prior to performing the backoff procedure, the EIFS for the extended range mode being longer than an EIFS for a non-extended range mode.

24. An apparatus for wireless communication, comprising:

at least one processor configured to;

make energy measurements of a wireless medium during a backoff procedure, each energy measurement being made over a measurement period covering multiple time slots; and

determine whether the wireless medium is clear or busy in each measurement period during the backoff procedure based on an energy measurement for the measurement period.

25. The apparatus of claim 24, wherein the at least one processor is configured to determine whether to continue or suspend the backoff procedure in each measurement period based on a determination of whether the wireless medium is clear of busy during the measurement period.

26. The apparatus of claim 24, wherein the at least one processor is configured to:

detect the wireless medium to be busy in a measurement period;

suspend the backoff procedure in response to detecting the wireless medium to be busy in the measurement period; and

resume the backoff procedure after detecting the wireless medium to be clear for an extended distributed coordination function (DCF) interframe space (DIFS), the extended DIFS being for an extended range mode and being longer than a DIFS for a non-extended range mode.

27. The apparatus of claim 24, wherein the at least one processor is configured to determine the wireless medium to be clear for an extended distributed coordination function (DCF) interframe space (DIFS) prior to performing the backoff procedure, the extended DIFS being for an extended range mode and being longer than a DIFS for a non-extended range mode.

28. The apparatus of claim 26, wherein the extended DIFS has a duration determined based on a length of a preamble of a message in the extended range mode.

29. The apparatus of claim 24, wherein the at least one processor is configured to:

detect a message transmitted via the wireless medium; and

wait for the wireless medium to be clear for an extended interframe space (EIFS) for an extended range mode prior to performing the backoff procedure, the EIFS for the extended range mode being longer than an EIFS for a non-extended range mode.