Method for maintaining wireless network response time while saving wireless adapter power

• US 7,877,117 B2
• Filed: 12/14/2006
• Issued: 01/25/2011
• Est. Priority Date: 04/30/2004
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Kostic, Igor A., Abhishek, Abhishek, Krantz, Anton W., Siddiqui, Adeel
• Primary Examiner(s): Nguyen; Tu X
• Application Number:
  US11/638,927
• Publication Number:
  US 20070093231A1
• Time in Patent Office: 1,503 Days
• Field of Search: 455/574, 455/127.5, 455/405, 455/414, 455/456.1, 455/453, 455/343.4
• US Class Current: 455/574
• 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

To reduce the power consumption of a wireless communication hardware device, power conservation scheduling algorithms can be implemented. Reoccurring events, including DTIM intervals and listen intervals can be scheduled as awake times. Similarly expected response intervals can be scheduled as awake times based on information, such as round trip time, that can be passed together with data to be transmitted. The wireless communication hardware device can be placed into a doze state unless it is transmitting data, or unless it is expecting a transmission during one of the scheduled awake times.

Claims

1. A method for conserving power consumed by wireless communication hardware of a computing device executing a communication application, the method comprising the steps of:

receiving a packet for transmission from higher level software comprising the communication application;

receiving, along with the data for transmission, through the driver scheduling related information from a plurality of sources, wherein the plurality of sources comprise the communication application and the wireless communication hardware, wherein the scheduling related information can be used to determine an expected response time for receiving an expected response related to the received packet for transmission, and wherein the driver comprises a data structure;

receiving information on at least one reoccurring event through interaction with at least one other wireless computing device;

transmitting the packet for transmission using the wireless communication hardware;

scheduling an awake state of the wireless communication hardware at a plurality of times by entering into the data structure a time value for each of the plurality of times, the plurality of time values comprising a time value based on the at least one reoccurring event and a time value based on the expected response time;

placing the wireless communication hardware into a doze state; and

in the doze state, processing entries of the data structure at a plurality of times, wherein the processing comprises;

determining whether an entry in the data structure indicates a time of a scheduled awake state matching a current time,

when a processed entry in the data structure indicates a time of a scheduled awake state matching a current time, placing the wireless communication hardware into the awake state at the scheduled time, and

when the processed entry in the data structure does not indicate a time matching a current time, causing the wireless communication hardware to remain in the doze state.

2. The method of claim 1, wherein the data structure comprises a timer array and wherein scheduling the awake state at a time of the plurality of times comprises:

entering scheduling information comprising an awake indicator into the timer array at a distance from a beginning of the time array corresponding to the scheduled time.

3. The method of claim 2, further comprising:

when a processed entry in the data structure includes the time value indicative of the awake state based on the reoccurring event, scheduling the awake state of the wireless communication hardware based on the reoccurring event.

4. The method of claim 2, further comprising:

placing the wireless communication hardware into a doze state if a transmission expected to be received during the awake state was received.

5. The method of claim 1, wherein the time value based on the expected response time comprises a time value based on the expected response time and a safety margin.

6. The method of claim 2, wherein the scheduling information comprises:

a wireless communication hardware state, indicating whether the wireless communication hardware is to be in the doze state or in the awake state; and

a wake up type, indicating a type of transmission expected to be received during the awake state.

7. The method of claim 1, wherein the at least one software layer above the driver comprises a transport driver.

8. A computer readable medium having computer executable instructions for, when executed by a processor, performing a method of conserving power consumed by wireless communication hardware, the method comprising:

receiving a packet for transmission from higher level software comprising a software layer above the interface and the wireless communication hardware;

receiving scheduling related information through an interface for the wireless communication hardware from a plurality of sources comprising the software layer above the interface and the wireless communication hardware along with the packet for transmission, wherein the scheduling related information can be used to determine an expected response time for receiving an expected response related to the packet for transmission, and wherein the driver comprises a data structure;

receiving information on at least one reoccurring event through interaction with at least one other wireless computing device;

transmitting the packet for transmission using the wireless communication hardware;

scheduling an awake state of the wireless communication hardware at a plurality of times by entering into the data structure a time value for each of the plurality of times, the plurality of time values comprising a time value based on the at least one reoccurring event and a time value based on the expected response time;

placing the wireless communication hardware into a doze state; and

during the doze state, processing entries of the data structure at predetermined time intervals, wherein the processing comprises;

determining whether an entry in the data structure indicates a time of a scheduled awake state matching a current time, and

when the processed entry in the data structure indicates a time of a scheduled awake state matching a current time, placing the wireless communication hardware into the awake state at the scheduled time.

9. The computer readable medium of claim 8, wherein the data structure comprises a timer array and wherein scheduling the awake state at a time of the plurality of times comprises:

entering scheduling information on the awake state comprising an awake indicator into the timer array at a distance from a beginning of the time array corresponding to the scheduled time.

10. The computer readable medium of claim 8, wherein the time value for scheduling the awake state based on the expected response time comprises a time value based on the expected response time and a safety margin.

11. The computer readable medium of claim 9, wherein the scheduling information comprises:

a wireless communication hardware state, indicating whether the wireless communication hardware is to be in the doze state or in the awake state; and

a wake up type, indicating a type of transmission expected to be received during the awake state.

12. The computer readable medium of claim 9, wherein the method further comprises:

maintaining the timer array;

processing an entry of the timer array; and

placing the wireless communication hardware into the awake state if the processed entry of the timer array indicated that the wireless communication hardware was to be in the awake state.

13. The computer readable medium of claim 8, wherein software layer above the interface comprises a transport driver.

14. The computer readable medium of claim 12, further comprising computer executable instructions for:

placing the wireless communication hardware into a doze state if a transmission expected to be received during the awake state was received.

15. A timer mechanism in a driver for wireless communication hardware for implementing, when processed by a processor, a power conservation schedule for the wireless communication hardware, the timer mechanism comprising:

a series of sequentially processed entries, wherein an entry of the series of sequentially processed entries comprises a state field for indicating an expected state of the wireless communication hardware and, when the expected state is an awake state, a wake up type field for indicating a type of transmission expected to be received during the awake state of the wireless communication hardware, and wherein further the series of sequentially processed entries are used to schedule the awake state of the wireless communication hardware using scheduling related information comprising information received by the driver from a plurality of sources comprising at least one software layer above the driver and the wireless communication hardware and information received by the driver through interaction with at least one other wireless communication device, wherein;

the information from the plurality of sources comprising the at least one software layer above the driver and the wireless communication hardware comprises an expected response time related to a packet for transmission received along with the scheduling related information,

the information received by the driver through interaction with the at least one other wireless communication device comprises at least one reoccurring event,

the awake state is scheduled, at a plurality of times, based on the expected response time and a reoccurring event time of the reoccurring event, and

during a doze state of the wireless communication hardware, entries of the series of sequentially processed entries are processed to determine whether an entry in the series of sequentially processed entries indicates a time value matching a current time, and, when the processed entry indicates a time value matching a current time, the wireless communication hardware is placed into the awake state.

16. The timer mechanism of claim 15, wherein the scheduling related information comprises information received with a packet for transmission and used to determine the expected response time.

17. The timer mechanism of claim 15, wherein processing an entry of the sequentially processed entries comprises:

placing the wireless communication hardware into the awake state if the state field of the processed entry indicated that the expected state of the wireless communication hardware was the awake state.

18. The timer mechanism of claim 15, wherein processing an entry of the sequentially processed entries comprises:

setting the state field of a later entry of the sequentially processed entries to indicate that the expected state of the wireless communication hardware is the awake state and setting the wake up type field of the later entry to indicate that transmission is associated with a reoccurring event, the setting the state field and the setting the wake up type field being performed if the wake up type field of the processed entry indicated that the transmission is associated with the reoccurring event, and wherein the later entry is selected based on an interval of the reoccurring event.

19. The timer mechanism of claim 15, wherein the wireless communication hardware is in a doze state unless the wireless communication hardware is transmitting data or is indicated to be in the awake state by the state field of a currently processed entry of the series of sequentially processed entries.

20. The timer mechanism of claim 15, wherein the timer mechanism is a timer array.