Method and apparatus for managing scanning in wireless computing devices to reduce power consumption

• US 8,102,798 B2
• Filed: 08/07/2007
• Issued: 01/24/2012
• Est. Priority Date: 12/18/2002
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Krantz, Anton W., Abhishek, Abhishek, Ayyagari, Arun, Ruan, Jiandong
• Primary Examiner(s): Corsaro, Nick
• Assistant Examiner(s): Johnson, Gerald
• Application Number:
  US11/834,793
• Publication Number:
  US 20080081618A1
• Time in Patent Office: 1,631 Days
• Field of Search: 455/434, 370/337, 709/229, 709/240
• US Class Current: 370/328
• CPC Class Codes: H04W 40/246 Connectivity information discovery
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A method and system for scanning in a wireless device having a wireless network interface card (NIC) is presented. The system has a scanning history table for storing scanning results and a scanning engine that adjusts the scanning period based upon a history of scanning results and commands the NIC to scan for available networks after the period has expired. The engine receives scan results from the NIC, stores the scan results in the scanning history table, determines a scanning period based upon a history of scan results, sets the scanning period, and commands the NIC to scan for available networks after the scanning period has expired. The engine is programmed to set the scanning period using an exponential function and to reset the scanning period to a default period if the scan results are different from a prior scan result or if a triggering event is received.

Claims

1. A method for managing scanning in a wireless device having a network interface module, the method comprising:

a) receiving results of a current scan from the network interface module, wherein the current scan is a scan for one or more other wireless devices within range of the wireless device;

b) storing the results of the current scan in a scanning history table;

c) determining a scanning period based at least in part upon a comparison of the results of the current scan with results of at least one prior scan;

d) setting the scanning period;

e) commanding the network interface module to scan for one or more other wireless devices within range of the wireless device after the scanning period has expired and after any traffic being sent or received when the scanning period expires is completely sent or received; and

f) repeating steps a-e.

2. The method of claim 1, wherein the current scan comprises a scan for available networks.

3. The method of claim 1, wherein determining the scanning period includes:

increasing the scanning period if the results of the current scan have not changed from the results of the at least one prior scan.

4. The method of claim 3, wherein increasing the scanning period comprises increasing the scanning period in accordance with a user preference.

11. The method of claim 1 wherein the network interface module is integrated with a processor.

5. A scanning system for use in a wireless device having a network interface module, the scanning system comprising:

a scanning history table for storing scanning results; and

a scanning engine for adjusting a scanning period based upon a history of scanning results and commanding the network interface module to scan for one or more other wireless devices within range of the wireless device after the scanning period has expired, wherein the scanning engine is programmed to;

a) receive results of a current scan from the network interface module, wherein the current scan is a scan for one or more other wireless devices within range of the wireless device;

b) store the results of the current scan in the scanning history table;

c) determine a scanning period based at least in part upon a comparison of the results of the current scan with results of a prior scan;

d) set the scanning period;

e) command the network interface module to scan for one or more other wireless devices within range of the wireless device after the scanning period has expired and after any traffic being sent or received when the scanning period expires is completely sent or received; and

f) repeat steps a-e.

6. The scanning system of claim 5, wherein the scanning engine is further programmed to reset the scanning period to a default period if the results of the current scan are different from the results of the prior scan.

12. The scanning system of claim 5 wherein the network interface module is integrated with a processor.

7. A computer-readable storage medium having computer-executable instructions for performing a method for managing scanning in a wireless device having a network interface module, the method comprising:

a) receiving results of a current scan from the network interface module, wherein the current scan is a scan for one or more other wireless devices within range of the wireless device;

b) storing the results of the current scan in a scanning history table;

c) setting a scanning period based at least in part upon a comparison of the results of the current scan with results of at least one prior scan;

d) commanding the network interface module to scan for one or more other wireless devices within range of the wireless device after the scanning period has expired and after any traffic being sent or received when the scanning period expires is completely sent or received; and

e) repeating steps a-d.

8. The computer readable storage medium of claim 7, wherein the current scan comprises a scan for available networks.

9. The computer readable storage medium of claim 7, wherein determining the scanning period includes:

increasing the scanning period if the results of the current scan have not changed from the results of the at least one prior scan.

10. The computer readable storage medium of claim 9, wherein increasing the scanning period comprises increasing the scanning period in accordance with a user preference.