Power saving method and related communication device

• US 8,725,220 B2
• Filed: 09/11/2012
• Issued: 05/13/2014
• Est. Priority Date: 01/05/2012
• Status: Active Grant

• Current Assignee: HTC Corporation
• Original Assignee: HTC Corporation
• Inventors: Chueh, Hsin-Ti, Gong, Win-Chyi, Hsieh, Wen-Jui, Lin, Chien-Nan, Fan, Chen-Huang, Tai, Chun, Su, Chang-Hsin, Shih, Chen-Han, Lee, Ching-Hao, Wang, Chi-Leng, Chen, Chia-Wei, Lai, Yu-Chuan, Kai, Chi-Sheng
• Primary Examiner(s): Ajibade Akonai, Olumide T
• Application Number:
  US13/609,311
• Publication Number:
  US 20130005333A1
• Time in Patent Office: 609 Days
• Field of Search: 455/432.1, 455/434, 455436-444, 455/448, 455/67.13, 455/522, 455/553.1, 455/574, 455/343.1, 370/311, 370/318, 370/328, 370/329, 370/330, 370/331, 370/332, 370/333
• US Class Current: 455/574
• CPC Class Codes: H04W 36/24 Reselection being triggered by specific parameters
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: H04W 52/0245 according to signal strength
• CPC Class Codes: H04W 52/0261 managing power supply demand, e.g. depending on battery level
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A power saving method for a mobile device in a wireless communication system is disclosed. The power saving method comprises obtaining a first parameter according to a first signal transmitted between the mobile device and a first network; estimating a first power consumption of the mobile device in the first network according to the first parameter and a first radio access technology (RAT) employed in the first network; determining whether the first network is suitable according to at least a comparison of the first power consumption with a second power consumption of the mobile device in a second network, wherein the second network employs a second RAT different from the first RAT; and switching to a the second network when the first network is not suitable.

Claims

1. A power saving method for a mobile device in a wireless communication system, the power saving method comprising:

obtaining a first parameter according to a first signal transmitted between the mobile device and a first network;

estimating a first power consumption of the mobile device in the first network according to the first parameter and a first radio access technology (RAT) employed in the first network;

determining whether the first network is suitable according to at least a comparison of the first power consumption with a second power consumption of the mobile device in a second network, wherein the second network employs a second RAT different from the first RAT; and

switching to the second network when the first network is not suitable;

wherein the estimating step comprises estimating a first average current of the mobile device in the first network by using a lookup table stored in the mobile device, and the lookup table is preset in the mobile device and indicates a correspondence among the first average current, the first parameter and the first RAT employed in the first network.

2. The power saving method of claim 1, wherein the step of determining whether the first network is suitable comprises:

determining the first network is not suitable when the first power consumption is greater than the second power consumption.

3. The power saving method of claim 1, wherein the mobile device is in a standby mode and before the step of determining whether the first network is suitable, the power saving method further comprising:

obtaining a second parameter according to a second signal transmitted between the mobile device and the second network; and

estimating the second power consumption according to the second parameter and the second RAT.

4. The power saving method of claim 1, wherein the mobile device is during a call with the first network, and the second power consumption is estimated according to a second parameter, which is previously obtained according to a second signal transmitted between the mobile device and the second network when the mobile device is in a standby mode.

5. The power saving method of claim 1, wherein the first parameter comprises at least one of a transmission (TX) level, a Timing Advance (TA) value and a received signal strength level;

the first and second power consumptions are average power consumptions of the mobile device during a call.

6. The power saving method of claim 5, wherein the step of switching to the second network is executed before the mobile device makes a call with the first network or during the call.

7. The power saving method of claim 1, wherein the first parameter comprises at least one of a received signal strength level and a discontinuous reception (DRX) cycle length;

the first and second power consumptions are average power consumptions when the mobile device is in a standby mode.

8. The power saving method of claim 7, wherein the step of switching to the second network is executed when the mobile device is in the standby mode.

9. A power saving method for a mobile device in a wireless communication system, the power saving method comprising:

connecting to a wireless local area network (WLAN);

checking which network the mobile device is camping on;

determining the WLAN stays connected for a first predetermined time when the mobile device is camping on a first network; and

handing off to a second network which employs a different radio access technology (RAT) from the first network.

10. The method of claim 9, wherein a first power consumption of the mobile device in the first network is higher than a second power consumption of the mobile device in the second network.

11. The method of claim 9, wherein the first network is a fourth or third generation wireless network and the second network is a second generation wireless network.

12. The method of claim 9 further comprising switching back to the first network when the WLAN is disconnected when the mobile device is camping on the second network.

13. The method of claim 12, wherein switching back to the first network when the WLAN is disconnected comprises:

switching back to the first network immediately when the WLAN is disconnected in a screen-on status of the mobile device.

14. The method of claim 12, wherein switching back to the first network when the WLAN is disconnected comprises:

determining the WLAN stays disconnected for a second predetermined time; and

switching back to the first network.

15. The method of claim 9, wherein connecting to the WLAN comprises connecting to the WLAN with the same service set identifier (SSID).

16. The method of claim 9 further comprising making a voice call via the second network and transferring data via the WLAN when the mobile device hands off to the second network.