Method and apparatus for managing power in network interface modules

• US 20040153676A1
• Filed: 01/31/2003
• Published: 08/05/2004
• Est. Priority Date: 01/31/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Moore, Timothy M., Abhishek, Abhishek, Ruan, Jiandong, Krantz, Anton W., Ayyagari, Arun, Barkley, Warren V., Geiger, Avi R.
• Granted Patent: US 7,340,615 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3209 Monitoring remote activity, e.g. over telephone lines or network connections
• CPC Class Codes: G06F 1/325 Power saving in peripheral device
• CPC Class Codes: H04M 2250/06 including a wireless LAN interface
• CPC Class Codes: H04W 52/0216 using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/0225 using monitoring of external events, e.g. the presence of a signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and system for managing power consumption in a portable computing device having a network interface module is presented. A power management module receives inputs from other modules and determines when the network interface module is to be put in a doze state for a predetermined number of beacon intervals to conserve power consumption in the network interface module. The network interface module in a device that is associated with a network is put in the doze state after an event has occurred including when a scan has been performed, after a delayed sleep timer has expired, and after a beacon transmission has been completed and no traffic is buffered for the device. The delayed sleep-time is set based on the estimated round trip time of a packet.

Claims

1. A method for managing power in a network interface module in a mobile device, the method comprising the steps of:

determining if the mobile device is being powered from a limited energy power source;

if the mobile device is being powered from the limited energy power source;

determining if the mobile device is associated with an access point;

operating the network interface module in one of a fast power save mode and a maximum power saving mode if the mobile device is associated with an access point;

if the mobile device is not associated with an access point;

determining if the network interface module is scanning;

operating the network interface module in a constant awake mode if the network interface module is scanning; and

setting the network interface module to a doze mode if the network interface module is not scanning.

2. The method of claim 1 further comprising the step of setting the network interface module to a constant awake mode if the mobile device is being powered from a power line source.

3. The method of claim 1 further comprising the step of setting the network interface module to one of the constant awake mode, the fast power save mode and the maximum power save mode in accordance with a user preference.

4. The method of claim 1 further comprising the step of setting the network interface module to the constant awake mode if one of the mobile device is associated and the scan has been requested.

5. The method of claim 1 further comprising the step of operating the network interface module in the fast power save mode if one of a packet has a high priority and an application tags a packet to indicate a fast response is required.

6. The method of claim 1 wherein the step of operating the network interface module in one of a fast power save mode and a maximum power saving mode if the mobile device is associated with a network comprises operating the network interface module in a fast power save mode.

7. The method of claim 6 wherein the step of operating the network interface module in a fast power save mode comprises the steps of:

a) determining when the network interface module can enter a doze state;

b) sending a notification to an access point that the network interface module is being set to the doze state;

c) setting the network interface module to the doze state after the notification has been sent;

d) setting the network interface module to an on state to receive a beacon for each beacon interval;

e) repeating steps b-f if the beacon indicates that no packets are queued for the mobile device; and

f) repeating steps a-f if the beacon indicates that at least one packet is queued for the mobile device.

8. The method of claim 7 further comprising the step of repeating steps a-f until one of the mobile device is disassociated with the access point and operation of the network interface module has been changed to one of the constant awake mode and the maximum power saving mode.

9. The method of claim 7 wherein the step of determining when the network interface module can enter a doze state comprises determining that a delayed sleep timer has expired.

10. The method of claim 7 wherein the step of determining when the network interface module can enter a doze state comprises determining that one of a delayed sleep timer has expired, a scan has been completed, a beacon indicates that no traffic is queued for the mobile device, and a power source switches from a limited energy power source to a power line source.

11. The method of claim 1 wherein the step of sending a notification to an access point that the network interface module is being set to the doze state comprises the step of sending the notification after all pending packets have been transmitted.

12. The method of claim 1 wherein the step of setting the network interface module to the doze state after the notification has been sent comprises setting a transmit path of the network interface module to a doze state and keeping a receive path of the network interface module powered.

13. The method of claim 1 wherein the step of operating the network interface module in one of a fast power save mode and a maximum power saving mode if the mobile device is associated with a network comprises operating the network interface module in a maximum power save mode.

14. The method of claim 13 wherein the step of operating the network interface module in a maximum power save mode comprises the steps of:

a) determining when the network interface module can enter a doze state;

b) sending a notification to an access point that the network interface module is being set to a doze state;

c) setting the network interface module to the doze state after the notification has been sent;

d) setting the network interface module to an on state to receive a beacon after a listening interval has passed;

e) repeating steps b-f if the beacon indicates that no packets are queued for the mobile device; and

f) repeating steps a-f if the beacon indicates that at least one packet is queued for the mobile device.

15. The method of claim 14 further comprising the step of repeating steps a-f until one of the mobile device is disassociated with the access point and operation of the network inter-face module has been changed to one of the constant awake mode and the fast power saving mode.

16. The method of claim 14 wherein the step of determining when the network interface module can enter a doze state comprises determining that a delayed sleep timer has expired.

17. The method of claim 14 wherein the step of determining when the network interface module can enter a doze state comprises determining that one of a delayed sleep timer has expired, a scan has been completed, a beacon indicates that no traffic is queued for the mobile device, and a power source switches from a limited energy power source to a power line source.

31. A computer readable medium having computer executable instructions for performing the steps of claim 1.

32. The computer readable medium of claim 31 having further computer executable instructions for performing the step of setting the network interface module to a constant awake mode if the mobile device is being powered from a power line source.

33. The computer readable medium of claim 31 having further computer executable instructions for performing the step of setting the network interface module to one of the constant awake mode, the fast power save mode and the maximum power save mode in accordance with a user preference.

34. The computer readable medium of claim 31 having further computer executable instructions for performing the step of setting the network interface module to the constant awake mode if one of the mobile device is associated and the scan has been requested.

35. The computer readable medium of claim 31 having further computer executable instructions for performing the step of operating the network interface module in the fast power save mode if an application tags a packet to indicate a fast response is required.

36. The computer readable medium of claim 31 wherein the step of sending a notification to an access point that the network interface module is being set to the doze state comprises the step of sending the notification after all pending packets have been transmitted.

37. The computer readable medium of claim 31 wherein the step of setting the network interface module to the doze state after the notification has been sent comprises setting a transmit path of the network interface module to a doze state and keeping a receive path of the network interface module powered.

38. The computer readable medium of claim 31 wherein the step of operating the network interface module in one of a fast power save mode and a maximum power saving mode if the mobile device is associated with a network comprises operating the network interface module in a fast power save mode, the step of operating the network interface module in a fast power save mode comprising the steps of:

a) determining when the network interface module can enter a doze state;

b) determining a delayed sleep time;

c) sending a notification to an access point that the network interface module is being set to the doze state;

d) setting the network interface module to the doze state after the notification has been sent;

e) setting the network interface module to an on state to receive a beacon for each beacon interval;

f) repeating steps c-g if the beacon indicates that no packets are queued for the mobile device; and

g) repeating steps a-g if the beacon indicates that at least one packet is queued for the mobile device.

39. The computer readable medium of claim 38 having further computer executable instructions for performing the step of repeating steps a-g until one of the mobile device is disassociated with the access point and operation of the network interface module has been changed to one of the constant awake mode and the maximum power saving mode.

40. The computer readable medium of claim 38 wherein the step of determining when the network interface module can enter a doze state comprises determining that a delayed sleep timer has expired.

41. The computer readable medium of claim 38 wherein the step of determining when the network interface module can enter a doze state comprises determining that one of a delayed sleep timer has expired, a scan has been completed, a beacon indicates that no traffic is queued for the mobile device, and a power source switches from a limited energy power source to a power line source

42. The computer readable medium of claim 31 wherein the step of operating the network interface module in one of a fast power save mode and a maximum power saving mode if the mobile device is associated with a network comprises operating the network interface module in a maximum power save mode, the step of operating the network interface module in a maximum power save mode comprises the steps of:

a) determining when the network interface module can enter a doze state;

b) determining a delayed sleep time;

c) sending a notification to an access point that the network interface module is being set to a doze state;

d) setting the network interface module to the doze state after the notification has been sent;

e) setting the network interface module to an on state to receive a beacon after a listening interval has passed;

f) repeating steps c-g if the beacon indicates that no packets are queued for the mobile device; and

g) repeating steps a-g if the beacon indicates that at least one packet is queued for the mobile device.

43. The computer readable medium of claim 42 having further computer executable instructions for performing the step of repeating steps a-g until one of the mobile device is disassociated with the access point and operation of the network interface module has been changed to one of the constant awake mode and the fast power saving mode.

44. The computer readable medium of claim 42 wherein the step of determining when the network interface module can enter a doze state comprises determining that one of a delayed sleep timer has expired, a scan has been completed, a beacon indicates that no traffic is queued for the mobile device, and a power source switches from a limited energy power source to a power line source.

18. A power management system for use in a mobile device having a network interface module comprising:

a power management module for controlling a power state of the network interface module to operate in one of a constant awake mode, a maximum power saving mode, and a fast power saving mode, the power management module comprising;

a power management backend module to determine when the network interface module is to be set to one of an on state and a doze state;

a system state module in communication with the power management backend module to provide system state information to the power management backend module; and

an interface list module in communication with the power management backend module to provide interface state information of the network interface module to the power management backend module.

19. The system of claim 18 further comprising a packet analyzer in communication with the power management module, the packet analyzer determining when the mobile device is not sending traffic.

20. The system of claim 18 further comprising a power supply indicator in communication with the power management module, the power supply indicator providing the power management module an indication if the mobile device is operating off a limited energy power source.

21. The system of claim 18 further comprising an application programming interface in communication with the power management module, the application programming interface providing an interface for an application to indicate that one of a packet requires a fast response and a packet has a high priority.

22. The system of claim 18 further comprising a power setting module in communication with the power management module, the power setting module providing an indication of a user preference of the power state.

23. The system of claim 18 further comprising a scanning engine in communication with the power management module, the scanning engine providing an indication to the program management module when the network interface module should be put in the on state for a scan.

24. The system of claim 18 wherein the power management backend module determines when the network interface module is to be set to one of an on state and a doze state using a state machine.

25. The system of claim 24 wherein the power management module determines that the network interface module is to be set to the doze state after one of a delayed sleep timer has expired, a scan has been completed, and a beacon indicates that no traffic is queued for the mobile device.

26. The system of claim 25 wherein the one of a delayed sleep timer has expired, a scan has been completed, and a beacon indicates that no traffic is queued for the mobile device comprises one of a delayed sleep timer has expired, a scan has been completed, a beacon indicates that no traffic is queued for the mobile device, and a power source switches from a limited energy power source to a power line source.

27. The system of claim 24 wherein the power management module determines that the network interface module is to be set to the on state after one of a notification that the mobile device has a packet to transmit is received, a notification that the network interface module needs to scan for available networks is received, a timer expires to indicate that the network interface module needs to receive a beacon, and a notification that the mobile device switches from a limited energy power source to a power line source is received.

28. The system of claim 18 wherein the power management module communicates with the network interface module using object identifiers, the object identifiers comprising:

a power state object identifier to perform one of setting the power state of the network interface module and querying the network interface module to determine the power state of the network interface module; and

a delayed sleep object identifier to perform one of setting a delayed sleep time and querying the network interface module to determine a present delayed sleep time.

29. The system of claim 28 wherein the power state object identifier has a plurality of settings comprising an on setting to switch the network interface module to the on state, a doze setting to switch the network interface module to the doze state, and an off setting to switch the network interface module to an off state.

30. The system of claim 28 wherein the delayed sleep time object identifier has a parameter setting to set the delay sleep time setting in milliseconds.

45. A method to send packets in a device having a network interface module operating in a power saving mode, the method comprising the steps of:

sending a packet to an access point for distribution;

setting a delay sleep timer to time out after a delay sleep time;

sending a message to the access point after the delay sleep timer has timed out to indicate the network interface module is entering a doze state; and

setting the network interface module to the doze state.

46. The method of claim 45 further comprising the step of resetting the delay sleep timer if at least one other packet is being sent to the access point while the delay sleep timer is counting.

47. The method of claim 45 further comprising the step of determining a delay sleep time for each of the packet and the at least one other packet.

48. The method of claim 45 further comprising the step of determining the delay sleep time for the packet.

49. The method of claim 48 wherein the step of determining the delay sleep time includes determining an estimated round trip time.

50. The method of claim 49 wherein the step of determining the delay sleep time includes setting the delay sleep time to the estimated round trip time if the estimated round trip time is lower than a beacon interval time.

51. The method of claim 48 wherein the step of determining the delay sleep time includes setting the delay sleep time to a time less than a beacon interval time if the estimated round trip time is at least a beacon interval time.

52. The method of claim 45 wherein the network interface module is transmitting packets from a plurality of sessions, the method further comprising the steps of:

determining a maximum round trip transmission time for the plurality of sessions; and

setting the delay sleep time to the maximum round trip time.

53. The method of claim 52 wherein the step of setting the delay sleep time to the maximum round trip time comprises the steps of:

setting the delay sleep time to the maximum round trip time if the estimated round trip time is lower than a beacon interval time; and

setting the delay sleep time to a time less than a beacon interval time if the maximum round trip time is at least a beacon interval time

54. A power management translator for providing power setting commands to a plurality of network interface modules in a mobile device comprising:

a system state module for receiving power settings from power setting components; and

an interface module for communicating a power setting to each network interface module.

55. The power management translator of claim 54 wherein the power setting components comprises at least one of a power supply indicator component, an API component, an user power setting component, a base power setting component, and a roaming component.

56. The power management translator of claim 54 wherein the interface module provides one of a high power setting, a medium power setting, and a low power setting to each network interface module.

57. The power management translator of claim 54 wherein the power management translator ignores a user power setting if the mobile device is being powered from an ac source.

58. The power management translator of claim 54 wherein the power management translator overrides a user power setting if a real-time application is engaged in a call.

59. The power management translator of claim 54 wherein the power management translator translates power settings from the power setting components to a single power setting for each network interface module.