Wireless device battery conservation method and system

• US 7,313,419 B2
• Filed: 03/06/2003
• Issued: 12/25/2007
• Est. Priority Date: 11/04/2002
• Status: Expired due to Fees

• Current Assignee: Malikie Innovations Limited (Key Patent Innovations Limited)
• Original Assignee: Blackberry Limited
• Inventors: Islam, Khaledul M., Hossain, Asif
• Primary Examiner(s): Ly, Nghi H.
• Application Number:
  US10/533,958
• Publication Number:
  US 20060068832A1
• Time in Patent Office: 1,755 Days
• Field of Search: 455/574, 455/343.1, 455/434, 455/342.1, 340/539.3, 340/7.32
• US Class Current: 455/574
• CPC Class Codes: H04W 52/0245 according to signal strength
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Generally, the present invention provides a method for detecting poor RF conditions, and entering different sleep mode levels or phases in accordance with the RF conditions to save battery power. Mobile device battery life can be conserved when the mobile device detects poor RF conditions and enters a deep sleep mode of operation. In this deep sleep mode of operation the mobile device periodically samples the RF conditions and gradually increases the period between samples when the RF conditions do not improve. Because mobility can change the RF condition for wireless devices even in areas of good RF coverage, the mobile device operating in the deep sleep mode can detect this mobility and thus enhance the probability of entering an idle state, or alternatively, entering a longer power save mode. When the RF condition improves, the mobile device exits from the deep sleep mode and returns to the idle state.

Claims

1. A method for switching a mobile device to a deep sleep mode comprising:

a) monitoring a system channel and resetting both a channel lost counter and a channel lost start time value;

b) counting a number of times the system channel is lost within a timeout period by incrementing the channel lost counter for each time the system channel is lost and setting the channel lost start time value to a first current Global Positioning System time when the channel lost counter value is one; and

,

c) entering the deep sleep mode when the system channel count equals a predetermined number.

2. The method of claim 1, wherein the step of monitoring includes monitoring one of a pilot channel and a paging channel of the system channel.

3. The method of claim 1, wherein the step of incrementing includes setting a channel lost end time value to a second current Global Positioning System time when the channel lost counter value has reached the predetermined number.

4. The method of claim 3, wherein the mobile device enters the deep sleep mode when the difference between the channel lost end time value and the channel lost start time value is at least the timeout period.

5. The method of claim 4, wherein the step of entering includes resetting the channel lost counter and the channel lost start time value after the mobile device enters the deep sleep mode.

6. A method for saving battery power in a mobile device switched to a deep sleep mode, the method comprising:

a) monitoring a system channel to determine;

a number of times the system channel is lost within a timeout period;

b) when the number of times the system channel is lost exceeds a predetermined number, entering a deep sleep mode level of the deep sleep mode, the deep sleep mode having first, second, and third deep sleep mode levels, each of the deep sleep mode levels having associated therewith a respective system acquisition list and a respective sleep time interval;

c) waking up from the deep sleep mode after elapse of the respective sleep time interval associated with the current deer sleep mode level;

d) iteratively sampling RF signal strength of systems in the respective system acquisition list associated with the current deer sleep mode level; and

,

e) if the sampled RF signal strength of the systems in the respective system acquisition list associated with the current deep sleep mode level is less than a predetermined level, re-entering the deep sleep mode at the subsequent deep sleep mode level.

7. The method of claim 6, wherein the step of re-entering the deep sleep mode includes comparing the signal to noise ratio of the RF condition to a predetermined value.

8. The method of claim 6, wherein the step of re-entering the deep sleep mode includes switching the mobile device to the second deep sleep mode level when the mobile device is in the first deep sleep mode level.

9. The method of claim 6, wherein the step of re-entering the deep sleep mode includes switching the mobile device to the third deep sleep mode level when the mobile device is in the second deep sleep mode level.

10. The method of claim 6, wherein the step of re-entering the deep sleep mode includes setting a maximum timeout period to a predetermined timeout value associated with one of the first, second and third level deep sleep modes.

11. The method of claim 10, wherein the step of re-entering the deep sleep mode includes switching the mobile device to one of the second and third deep sleep mode levels when the maximum timeout period expires.

12. The method of claim 6, wherein the system acquisition list associated with the first deep sleep mode level is a subset of the system acquisition list associated with the second deep sleep mode level and the system acquisition list associated with the third deer sleep mode level, and the system acquisition list associated with the second deer sleep mode level is a subset of the system acquisition list associated with the third deer sleep mode level.

13. The method of claim 12, wherein the system acquisition list associated with the first deep sleep mode level is a Most Recently Used (MRU) Table list.

14. The method of claim 12, wherein the system acquisition list associated with the second deep sleep mode level is a Most Recently Used (MRU) Table list and a Geographical Region (Idle GEO) list.

15. The method of claim 12, wherein the system acquisition list associated with the third deep sleep mode level is a Most Recently Used (MRU) Table list, a Geographical Region (Idle GEO) list and a Preferred Roaming List (PRL).

16. The method of claim 6, wherein the step of re-entering the deer sleep mode includes setting a maximum loop counter value to a predetermined counter value associated with one of the first, second and third deep sleep mode levels.

17. The method of claim 16, wherein the step of re-entering the deep sleep mode includes setting a mobility flag to true or if the mobile device is moving.

18. The method of claim 16, wherein the step of re-entering the deep sleep mode includes setting the time interval to a predetermined time value associated with one of the first, second and third deep sleep mode levels.

19. The method of claim 18, wherein the predetermined time value associated with the second deep sleep mode level is greater than the predetermined time value associated with the first deep sleep mode level.

20. The method of claim 19, wherein the predetermined time value associated with the third deep sleep mode level is greater than the predetermined time value associated with the second deep sleep mode level.

21. The method of claim 16, wherein the step of re-entering the deep sleep mode includes setting a mobility flag to true if a Pseudo Noise of the system is unknown.

22. The method of claim 21, wherein a phase of the Pseudo Noise is monitored for determining mobility of the mobile device.

23. The method of claim 21, wherein the mobile device returns to one of an idle state and the first deep sleep mode level when the mobility flag is true.

24. The method of claim 23, wherein the step of re-entering the deep sleep mode includes

(i) incrementing a loop counter when the mobility flag is false;

(ii) comparing the loop counter value to the maximum loop counter value; and

,

(iii) switching the mobile device to one of the second and third deep sleep mode levels when the loop counter value equals the maximum loop counter value.

25. The method of claim 24, wherein step of switching includes switching the mobile device to the second deep sleep mode level when the mobile device is in the first deep sleep mode level.

26. The method of claim 24, wherein step of switching includes switching the mobile device to the third deep sleep mode level when the mobile device is in the second deep sleep mode level.

27. A mobile device battery power saving system, comprising:

a) a channel processor for providing a flag signal indicating loss of a system channel;

b) a deep sleep controller for receiving the flag signal, counting a number of times the system channel is lost within a timeout period, and providing a system lost exit flag for entering a deep sleep mode level of the deep sleep mode, the deep sleep mode having first, second, and third deep sleep mode levels, each of the deep sleep mode levels having associated therewith a respective system acquisition list and a respective sleep time interval, when the system channel count equals a predetermined number;

c) a variable setting controller for setting deep sleep mode level variables in response to the system lost exit flag and for adjusting the deep sleep mode variables in response to control signals; and

,

d) a low power controller for iteratively sampling an RF condition parameter at a time interval defined by the deep sleep mode variables and for providing the control signals to the variable setting controller when the RF condition fails to improve.

28. The mobile device battery power saving system of claim 27, wherein the system channel includes one of a pilot channel and a paging channel.

29. The mobile device battery power saving system of claim 27, wherein the deep sleep mode level variables include a timer value for setting the time interval and a loop count value for setting a number of iterations.

30. The mobile device battery power saving system of claim 27, wherein the RF condition parameter includes a signal to noise strength ratio.