POWER SAVING WI-FI TETHERING

• US 20140126391A1
• Filed: 11/06/2012
• Published: 05/08/2014
• Est. Priority Date: 11/06/2012
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Liu, Yunxin, Shen, Guobin, Zhang, Yongguang, Han, Hao
• Granted Patent: US 9,247,495 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04W 52/0206 in access points, e.g. base stations access point devices per se H04W88/08
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The techniques discussed herein reduce the power consumption of a Wi-Fi tethering device by switching the Wi-Fi functionality of the Wi-Fi tethering device from a normal operational mode to a sleep mode during idle intervals. The techniques implement a sleep protocol where a Wi-Fi tethering device and the Wi-Fi client device coordinate and establish a sleep schedule. Moreover, the techniques describe a sleep interval adaptation algorithm to establish sleep duration intervals based on data packet exchange patterns associated with different applications executing on the Wi-Fi client device and/or different operations being performed by the Wi-Fi client device.

Claims

1. A method comprising:

monitoring, during a normal operational mode, communications by a Wi-Fi network interface of a Wi-Fi tethering device to identify an idle interval where no data packets are exchanged between the Wi-Fi tethering device and a Wi-Fi client device using the Wi-Fi network interface;

determining, at the Wi-Fi tethering device, that the idle interval has reached or exceeded a pre-defined amount of time;

determining, at the Wi-Fi tethering device, a sleep duration interval that is an amount of time that the Wi-Fi network interface remains inactive in a sleep mode;

generating a sleep request to send from the Wi-Fi tethering device to the Wi-Fi client device, the sleep request including the sleep duration interval;

receiving a sleep response at the Wi-Fi tethering device from the Wi-Fi client device, the sleep response accepting the sleep request; and

switching the Wi-Fi network interface from the normal operational mode to the sleep mode, the Wi-Fi tethering device using less power while operating in the sleep mode than when operating in the normal operational mode.

2. The method recited in claim 1, further comprising:

receiving one or more data packets after the Wi-Fi network interface has switched to the sleep mode;

storing the one or more data packets in a buffer;

switching the Wi-Fi network interface from the sleep mode to the normal operational mode in response to expiration or passage of the sleep duration interval; and

sending the one or more data packets stored in the buffer to the Wi-Fi client device.

3. The method recited in claim 2, wherein the one or more data packets are received via a network connection to a content server.

4. The method recited in claim 1, wherein the sleep duration interval is between a minimum threshold time and a maximum threshold time, the minimum threshold time selected to cause a reduction in power consumption during the operation of the Wi-Fi tethering device, and the maximum value selected to avoid excessive latency.

5. The method recited in claim 4, wherein the minimum threshold time is at least 100 milliseconds (ms) and the maximum threshold time is at least 500 ms.

6. The method recited in claim 1, wherein the sleep duration interval is determined based at least in part on a length of a previous idle interval for the Wi-Fi network interface.

7. The method recited in claim 1, further comprising:

determining, at the Wi-Fi tethering device, a subsequent sleep duration interval after the sleep duration interval expires;

generating a second sleep request to send from the Wi-Fi tethering device to the Wi-Fi client device, the second sleep request including the subsequent sleep duration interval;

receiving a second sleep response at the Wi-Fi tethering device from the Wi-Fi client device, the second sleep response accepting the second sleep request; and

maintaining the Wi-Fi network interface in the sleep mode based at least in part on the second sleep response.

8. The method recited in claim 7, wherein the sleep duration interval is determined based on a short sleep stage associated with a content fetching phase of interaction between the Wi-Fi tethering device and the Wi-Fi client device and the subsequent sleep duration interval is determined based on a long sleep stage associated with a content consuming phase of interaction between the Wi-Fi tethering device and the Wi-Fi client device.

9. The method recited in claim 1, wherein the sleep duration interval is determined based at least in part on a frequency of receipt, by the Wi-Fi tethering device, of data packets associated with one or more applications executing on the Wi-Fi client device.

10. One or more computer storage media storing computer executable instructions that, when executed, perform operations comprising:

identifying, during a normal mode of operation, an idle time for a Wi-Fi network interface where no data packets are being exchanged between a Wi-Fi tethering device and a Wi-Fi client device using the Wi-Fi network interface;

coordinating a sleep schedule for the Wi-Fi network interface during the idle time, the coordinating including an agreement between a Wi-Fi tethering device and a Wi-Fi client device to switch the Wi-Fi network interface from the normal mode of operation to a sleep mode for one or more lengths of time;

switching the Wi-Fi network interface to the sleep mode for a total amount of time associated with the one or more lengths of time; and

waking up the Wi-Fi network interface from the sleep mode and switching to the normal mode of operation in response to expiration or passage of the total amount of time.

11. The one or more computer storage media recited in claim 10, wherein the coordinating operation is performed when the idle time passes a pre-defined threshold amount of time.

12. The one or more computer storage media recited in claim 11, wherein the pre-defined threshold amount of time is less than three hundred milliseconds.

13. The one or more computer storage media recited in claim 10, wherein the coordinating operation is performed in accordance with a sleep request and sleep response protocol that communicates the agreement.

14. The one or more computer storage media recited in claim 10, wherein at least one of the one or more lengths of time is determined using an adaptive algorithm that uses an idle interval history for the Wi-Fi network interface.

15. The one or more computer storage media recited in claim 10, wherein at least one of the one or more lengths of time is based on a short sleep stage associated with a content fetching phase where data packets are being requested or downloaded through the Wi-Fi network interface.

16. The one or more computer storage media recited in claim 10, wherein at least one of the one or more lengths of time is based on a long sleep stage associated with a content consuming phase where data packet communication is suspended while content is being consumed on the Wi-Fi client device.

17. The one or more computer storage media recited in claim 10, further comprising computer executable instructions that perform operations comprising:

storing one or more data packets received by the Wi-Fi network interface in a buffer while the Wi-Fi network interface is in sleep mode; and

sending the one or more data packets stored in the buffer to the Wi-Fi client device after the Wi-Fi network interface wakes up and is switched to the normal mode of operation in response to expiration or passage of the total amount of time.

18. A system comprising:

one or more processors;

a Wi-Fi network interface; and

one or more computer memories, coupled to the one or more processors and storing;

a sleep interval determination module, operable by the one or more processors, that determines one or more sleep duration intervals for the Wi-Fi network interface during an idle time of the Wi-Fi network interface where no data packets are being exchanged between the system and a Wi-Fi client device using the Wi-Fi network interface; and

a sleep scheduling module, operable by the one or more processors, that;

sends one or more sleep requests to a Wi-Fi client device, the one or more sleep requests communicating the one or more sleep duration intervals;

receives one or more sleep responses from the Wi-Fi client device that indicate an agreement for the Wi-Fi network interface to sleep for a period of time based at least in part on the one or more sleep duration intervals; and

switches the Wi-Fi network interface from a normal mode of Wi-Fi communication to a sleep mode, the system consuming less power while operating in the sleep mode than when operating in the normal mode.

19. The system as recited in claim 18, wherein the sleep interval determination module determines at least one sleep duration interval based at least in part on a previous idle interval.

20. The system as recited in claim 18, wherein the sleep scheduling module further receives data packets during the sleep mode of the Wi-Fi network interface and stores the data packets in a packet buffer for future communication to the Wi-Fi client device.