Handling wrong WEP key and related battery drain and communication exchange failures

• US 20110085447A1
• Filed: 04/13/2010
• Published: 04/14/2011
• Est. Priority Date: 10/11/2009
• Status: Active Grant

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Research In Motion Limited (Blackberry Limited)
• Inventors: Mendahawi, Nayef Fawaz, Barbu, Ion, Kholaif, Ahmad Mohammad, Bakthavathsalu, Krishna Kumar
• Granted Patent: US 8,427,991 B2
• Time in Patent Office: Days
• US Class Current: 370/242
• CPC Class Codes: H04W 12/0433 Key management protocols
• CPC Class Codes: H04W 12/069 using certificates or pre-shared keys
• CPC Class Codes: H04W 12/125 Protection against power exhaustion attacks
• 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 power reduction mechanism in a mobile communications device detects the use of a wrong WEP encryption key in the establishment of a WLAN connection between the mobile device and an access point for both static and dynamic IP WLAN profiles. The power reduction mechanism detects an incorrect WEP key; authentication failure; failure to acquire an IP address for dynamic IP WLAN profiles; decryption errors; and broadcast/multicast frames from the handset not being redirected back to the BSS by the AP. Upon such detection, the mobile device takes one or more power conserving actions, e.g., adding the AP/profile to a ban list; attempting WLAN association for a banned AP/profile at longer intervals than for a non-banned AP/profile; skipping an AP/profile on the ban list for a time duration defined by a timer to conserve power; and flagging the banned AP/profile with a special mark to indicate it is banned.

Claims

1. A method of reducing power consumption in a wireless communications device, said method comprising:

attempting to establish a connection between said wireless communication device and an access point (AP) utilizing a profile;

monitoring communications exchange between said wireless communications device and said AP;

as a result of said monitoring, detecting use of an incorrect wired equivalent privacy (WEP) key; and

in response to said detecting use of an incorrect WEP key, disabling said corresponding profile and related active scanning and association thereby reducing power consumption of said wireless communication device.

2. The method according to claim 1, wherein said communications exchange comprises authentication frames.

3. The method according to claim 1, wherein said communications exchange comprises data frames.

4. The method according to claim 1, wherein said attempting comprises authentication and association processes.

5. The method according to claim 1, wherein said use of a wrong WEP key is detected in response to an authentication failure.

6. The method according to claim 1, wherein said use of a wrong WEP key is detected in response to receipt of one or more decryption errors in downlink packets.

7. The method according to claim 1, wherein said use of a wrong WEP key is detected after a plurality of transmitted packets remains unacknowledged.

8. The method according to claim 1, wherein said detecting a wrong WEP key comprises broadcasting or multicasting packets and failing to receive said packets on said wireless communication device.

9. The method according to claim 1, wherein said use of a wrong WEP key is detected after continuous dynamic host control protocol (DHCP) failures including an inability to obtain an Internet Protocol (IP) address.

10. The method according to claim 1, further comprising disassociating from said AP in response to said detecting use of an incorrect WEP key.

11. The method according to claim 1, further comprising notifying a user via a user interface (UI) in response to said detecting use of an incorrect WEP key.

12. The method according to claim 1, further comprising, in response to said detecting use of an incorrect WEP key, excluding said AP from said profile and related active scanning and association on a temporary basis until said profile is modified by a user.

13. The method according to claim 1, further comprising, in response to said detecting use of an incorrect WEP key, adding said AP to a ban list whereby the time said AP is on said list dynamically increases with repeated detection of use of an incorrect WEP key.

14. The method according to claim 1, further comprising, in response to said detecting use of an incorrect WEP key, disabling said profile on a basic service set identifier/service set identifier (BSSID/SSID) basis thereby allowing said mobile communication device to connect with other APs belonging to the same profile.

15. The method according to claim 1, further comprising, in response to an authentication failure, disabling said corresponding profile and related active scanning and association thereby reducing power consumption of said wireless communication device.

16. A method of reducing power consumption in a wireless communications device, said method comprising:

attempting to establish a connection between said wireless communication device and an access point (AP) utilizing a profile;

monitoring a communications exchange process between said wireless communications device and said AP;

as a result of said monitoring, detecting a failure to obtain an Internet Protocol (IP) address during a dynamic host control protocol (DHCP) process; and

in response to said detecting said failure to obtain an IP address, disabling said corresponding profile and related active scanning and association thereby reducing power consumption of said wireless communication device.

17. The method according to claim 16, further comprising, in response to said failure to obtain an IP address, excluding said AP from said profile and related active scanning and association on a temporary basis until said profile is modified by a user.

18. The method according to claim 16, further comprising, in response to said failure to obtain an IP address, adding said AP to a ban list whereby the time said AP is on said list dynamically increases with repeated failure to obtain an IP address.

19. The method according to claim 16, further comprising, in response to said failure to obtain an IP address, disabling said profile on a basic service set identifier/service set identifier (BSSID/SSID) basis thereby allowing said mobile communication device to connect with other APs belonging to the same profile.

20. A mobile communications device, comprising:

one or more radio circuits;

a memory;

a processor coupled to said one or more radio circuits and said memory, said processor operative to

monitor a communications exchange between said mobile communications device and an access point (AP) during an attempt to establish a connection therebetween using a profile;

as a result of said monitoring, detect use of an incorrect wired equivalence privacy (WEP) key; and

in response to detecting use of an incorrect WEP key, disable said corresponding profile and related active scanning and association thereby reducing power consumption of said wireless communication device.

21. The mobile communications device according to claim 20, said processor operative to, in response to said detecting use of an incorrect WEP key, add said AP to a ban list whereby the time said AP is on said list dynamically increases with repeated detection of use of an incorrect WEP key.

22. The mobile communications device according to claim 20, said processor operative to, in response to said detecting use of an incorrect WEP key, disable said profile on a basic service set identifier/service set identifier (BSSID/SSID) basis thereby allowing said mobile communication device to connect with other APs belonging to the same profile.

23. A mobile communications device, comprising:

one or more radio circuits;

a memory;

a processor coupled to said one or more radio circuits and said memory, said processor operative to

monitor a communications exchange between said mobile communications device and an access point (AP) during an attempt to establish a connection therebetween using a profile;

as a result of monitoring, detect a failure to obtain an Internet Protocol (IP) address during a dynamic host control protocol (DHCP) process; and

in response to detecting a failure to obtain an IP address, disabling said corresponding profile and related active scanning and association thereby reducing power consumption of said wireless communication device.

24. The mobile communications device according to claim 23, said processor operative to, in response to said failure to obtain an IP address, add said AP to a ban list whereby the time said AP is on said list dynamically increases with repeated failure to obtain an IP address.

25. The mobile communications device according to claim 23, said processor operative to, in response to said failure to obtain an IP address, disable said profile on a basic service set identifier/service set identifier (BSSID/SSID) basis thereby allowing said mobile communication device to connect with other APs belonging to the same profile.

26. A computer program product for reducing power consumption in a wireless communications device, the computer program product comprising:

a computer usable medium having computer usable code embodied therewith, the computer usable program code comprising;

computer usable code configured for attempting to establish a connection between said wireless communication device and an access point (AP) utilizing a profile;

computer usable code configured for monitoring a communications exchange process between said wireless communications device and said AP;

computer usable code configured for detecting use of an incorrect wired equivalent privacy (WEP) key, as a result of said monitoring; and

computer usable code configured for disabling, in response to detecting use of an incorrect WEP key, said corresponding profile and related active scanning and association thereby reducing power consumption of said wireless communication device.