Direct digital signal processor control of multi-channel scan for re-establishing connections in a wirelessly networked device

Patent metadata

Field	Value
Publication number	US-9232552-B2
Application number	US-201414320292-A
Country	US
Kind code	B2
Filing date	Jun 30, 2014
Priority date	May 1, 2001
Publication date	Jan 5, 2016
Grant date	Jan 5, 2016

Abstract

A method and system for establishing a wireless connection between a portable computer system and a wireless network, particularly when the portable computer system goes out of coverage and a wireless connection needs to be re-established. The portable computer system has a main processor and a digital signal processor (DSP). The main processor is placed in a low power mode, conserving battery power. When the portable computer system goes out of coverage, broadcast channels used by the wireless network are scanned by the DSP instead of the main processor to identify channels that have sufficient signal strength for the wireless connection. Thus, the main processor remains in the low power mode. When the DSP identifies acceptable channels, it wakes up the main processor and identifies the channels having sufficient signal strength. The main processor then establishes a wireless connection using one of the channels identified by the DSP.

First claim

What is claimed is:

1. In a portable computer system including at least a first processor and a second processor, a method of establishing a wireless connection between the portable computer system and a wireless network, the method performed by the portable computer system and comprising:
scanning a plurality of broadcast channels using the second processor while the first processor is in a sleep mode;
determining which of the broadcast channels are acceptable for the wireless connection using the second processor while the first processor is in the sleep mode;
ranking the acceptable broadcast channels according to signal strengths using the second processor;
waking the first processor from the sleep mode;
selecting, using the first processor, one of the acceptable broadcast channels from the ranking; and
establishing the wireless connection with the selected broadcast channel using the first processor.

2. The method of claim 1 , wherein the determining comprises:
comparing a signal strength of each of the broadcast channels with a threshold indicating a minimum acceptable signal strength.

3. The method of claim 1 , further comprising:
returning the first processor to the sleep mode after the wireless connection is established.

4. The method of claim 1 , further comprising:
providing information indicating the ranking of the acceptable broadcast channels to the first processor.

5. The method of claim 4 , wherein the first processor is awakened from the sleep mode in response to receiving the information.

6. The method of claim 1 , wherein the scanning comprises:
disregarding one or more of the broadcast channels based, at least in part, on noise levels of the broadcast channels.

7. The method of claim 1 , wherein the scanning is initiated when a previously established wireless connection between the portable computer system and the wireless network is lost.

8. The method of claim 1 , further comprising:
continuing the scanning of the plurality of broadcast channels when none of the broadcast channels are determined to be acceptable.

9. The method of claim 1 , wherein the second processor comprises a digital signal processor.

10. A portable computer system to establish a wireless connection with a wireless network, the portable computer system comprising:
a first processor;
a second processor coupled to the first processor;
a memory storing instructions that, when executed by the second processor, cause the second processor to perform operations comprising:
placing the first processor in a sleep mode;
scanning a plurality of broadcast channels;
determining which of the broadcast channels are acceptable for the wireless connection;
waking the first processor from the sleep mode; and
providing a list of the acceptable broadcast channels to the first processor.

11. The portable computer system of claim 10 , wherein execution of the instructions to perform the determining causes the second processor to:
compare a signal strength of each of the broadcast channels with a threshold indicating a minimum acceptable signal strength.

12. The portable computer system of claim 10 , further comprising instructions stored in the memory that, when executed by the first processor, cause the first processor to perform operations comprising:
selecting, from the list of acceptable broadcast channels, the broadcast channel having a highest signal strength; and
establishing the wireless connection with the selected broadcast channel.

13. The portable computer system of claim 12 , wherein execution of the instructions causes the second processor to perform steps further comprising:
returning the first processor to the sleep mode after the wireless connection is established.

14. The portable computer system of claim 10 , wherein execution of the instructions causes the second processor to perform steps further comprising:
ranking the acceptable broadcast channels according to signal strengths.

15. The portable computer system of claim 10 , wherein the first processor is awakened from the sleep mode in response to receiving the list.

16. The portable computer system of claim 10 , wherein execution of the instructions to perform the scanning causes the second processor to:
disregard one or more of the broadcast channels based, at least in part, on noise levels of the broadcast channels.

17. The portable computer system of claim 10 , wherein the scanning is initiated when a previously established wireless connection between the portable computer system and the wireless network is lost.

18. The portable computer system of claim 10 , wherein execution of the instructions causes the second processor to perform steps further comprising:
continuing the scanning of the plurality of broadcast channels when none of the broadcast channels are determined to be acceptable.

19. The portable computer system of claim 10 , wherein the second processor comprises a digital signal processor.

20. A non-transitory computer-readable medium containing program instructions that, when executed by a portable computer system including at least a first processor and a second processor, cause the portable computer system to establish a wireless connection with a wireless network by performing operations comprising:
scanning a plurality of broadcast channels using the second processor while the first processor is in a sleep mode;
determining which of the broadcast channels are acceptable for the wireless connection using the second processor while the first processor is in the sleep mode;
ranking the acceptable broadcast channels according to signal strengths using the second processor;
waking the first processor from the sleep mode;
selecting, using the first processor, one of the acceptable broadcast channels from the ranking; and
establishing the wireless connection with the selected broadcast channel using the first processor.

21. The non-transitory computer-readable medium of claim 20 , wherein execution of the instructions perform the determining by:
comparing a signal strength of each of the broadcast channels with a threshold indicating a minimum acceptable signal strength.

22. The non-transitory computer-readable medium of claim 20 , wherein execution of the instructions causes the portable computer system to perform steps further comprising:
returning the first processor to the sleep mode after the wireless connection is established.

23. The non-transitory computer-readable medium of claim 20 , wherein execution of the instructions causes the portable computer system to perform steps further comprising:
providing information indicating the ranking of the acceptable broadcast channels to the first processor.

24. The non-transitory computer-readable medium of claim 23 , wherein the first processor is awakened from the sleep mode in response to receiving the information.

25. The non-transitory computer-readable medium of claim 20 , wherein execution of the instructions to perform the scanning causes the second processor to:
disregard one or more of the broadcast channels based, at least in part, on noise levels of the broadcast channels.

26. The non-transitory computer-readable medium of claim 20 , wherein the scanning is initiated when a previously established wireless connection between the portable computer system and the wireless network is lost.

27. The no

Assignees

• Qualcomm Inc

Inventors

• Skinner Craig S
• Brown John
• Wong William

Classifications

• H04W72/30

  Resource management for broadcast services · CPC title

• H04W52/0209 Primary

  in terminal devices · CPC title

• H04W52/0245

  according to signal strength · CPC title

• Y02B60/50

  Cross-Sectional Technologies · mapped topic

• H04W76/028 Primary

  Electricity · mapped topic