METHOD AND APPARATUS FOR ADAPTIVE BLUETOOTH LOW POWER DISCOVERY AND WAKE UP

• US 20100153762A1
• Filed: 11/17/2009
• Published: 06/17/2010
• Est. Priority Date: 11/19/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Rauber, Peter H., Radulescu, Andrei
• Granted Patent: US 8,307,231 B2
• Time in Patent Office: Days
• US Class Current: 713/323
• CPC Class Codes: H04M 1/72412 using two-way short-range wireless interfaces
• CPC Class Codes: H04W 52/0274 by switching on or off the equipment or parts thereof
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method of low power discovery (LPD) that extends the battery life of a portable Wi Fi device or portable media player (PMP) using IEEE 802.11 interface by ensuring that PMP host processor is only on when in designated 802.11 coverage or when needed by a user, by employing probabilistic channel scanning-comprising:

• • A) bringing an AT host equipped with an 802.11 interface to an advanced configuration and power interface (ACPI) state S3 or equivalent sleep state, and prior to said device or media player going to sleep; and
  • B) programming the 802.11 WLAN to wake up based on a predetermined trigger logic.

Claims

1. A method of low power discovery (LPD) that extends the battery life of a portable Wi Fi device or portable media player (PMP) using IEEE 802.11 interface by ensuring that PMP host processor is only on when in designated 802.11 coverage or when needed by a user, by employing probabilistic channel scanning-comprising:

A) bringing an AT host equipped with an 802.11 interface to an advanced configuration and power interface (ACPI) state S3 or equivalent sleep state, and prior to said device or media player going to sleep; and

B) programming the 802.11 WLAN to wake up based on a predetermined trigger logic.

3. The method of claim 1, wherein said predetermined trigger logic is a desired services set identifier (SSID).

4. The method of claim 1, wherein said predetermined trigger logic is a desired encryption.

5. The method of claim 1, wherein said predetermined trigger logic is a predetermined packet format from an AP.

6. The method of claim 1, wherein said predetermined trigger logic is a wakeup necessity through synchronization token.

7. The method of claim 6, wherein said synchronization token is unencrypted to accommodate limited media access control (MAC) processor.

8. The method of claim 7, wherein said synchronization token is sent by the AT to the AP when desired 802.11 coverage is found.

9. The method of claim 7, wherein the MAC address allows the AP to wake-up only specific ATS, on the basis of the need for wake-up, as determined after analyzing the AT'"'"'s synchronization token.

10. The method of claim 1, wherein the channels are scanned probabilistically based upon one or more of the following:

a) history of found channels or trigger;

b) pre-programmed trigger information downloaded from a server;

or

c) information from a sensor of the likelihood of an 802.11 channel.

11. The method of claim 10, wherein said sensor is a GPS.

12. The method of claim 10, wherein said sensor is a Bluetooth.

13. The method of claim 10, wherein said sensor is a gyroscope.

14. The method of claim 10, wherein said sensor is an odometer.

15. The method of claim 10, wherein said sensor is a cellular signal.

16. The method of claim 6, wherein during LPD, and prior to the host going into standby, the host updates the synchronization token and downloads it to the MAC processor.

17. The method of claim 16, wherein the token marks a level of download that has been reached.

18. The method of claim 16, wherein the token marks changes in some download list.

19. The method of claim 16, wherein the token marks the latest retrieved e-mail.

20. The method of claim 7, wherein trigger logic is implemented in MAC processor firmware.

2. A method of low power discovery (LPD) that intending the battery life of a portable Wi Fi device or portable media player (PMP) using IEEE 802.11 interface by ensuring that the PMP host processor is only on when in designated 802.11 coverage or when needed by a user, by employing probabilistic channel scanning comprising:

A) bringing an AT host equipped with an 802.11 interface to an advanced configuration and power interface (ACPI) state S3 or equivalent sleep state, and prior to said device or media player going to sleep;

B) programming a Bluetooth (BT) device at the AT to look for a certain IAC (inquiring access code), whereupon finding said IAC, the AT sends a BT inquiring reply directing an AP to wake-up said PMP via a wake-up packet.

21. The method of claim 2, wherein said wake-up packet is a magic packet-ready motherboard.

22. The method of claim 2, wherein said BT inquiry is sent to advertise the availability of the 802.11 AP.

23. The method of claim 22, wherein said inquiry is sent as a dedicated inquiry access code (DIAC), with its lower access portion (LAP) corresponding to an unusual device.

24. The method claim 2, wherein said IAC is sent by using a most significant bits (MSB) field.

25. The method of claim 2, wherein the 802.11 channel is sent in a BT data packet.

26. The method of claim 25, wherein PMP firmware tunes the 802.11 interface to the advertised AP channel.

27. The method of claim 26, wherein if no 802.11 channel information is sent by the AP, the PMP firmware has the option of:

i) waking up the host processor and handing 802.11 channel scanning to it, or

ii) using a BT packet to send a synchronization token to the AP, along with the AT'"'"'s 802.11 channel number.

28. The method of claim 27, wherein, if the AP'"'"'s initial inquiry included a packet number, or the PMP firmware follows option ii), and the firmware on the PMP (AT) sends either:

iii) a BT inquiry reply, informing the AP of the PMP'"'"'s vicinity, followed by an optional synchronization token packet through a regular BT packet or

iv) an 802.11 packet on the specified channel in the form of an association request, with the synchronization token.

29. The method of claim 28, wherein after step iv) the AP targets a wakeup packet to the PMP'"'"'s 802.11 interface.

30. The method of claim 29, wherein, to target the wakeup packet, the AP uses the PMP'"'"'s MAC address.

31. The method of claim 30, wherein a 48-bit MAC address for the wakeup packet has been sent by this time, either:

a) through the BT inquiry reply in the LAP+UAP+NAP fields, or

b) through the MAC address of the standard 802.11 association request frame.