Dynamic thermal control for wireless transceivers

• US 20100091691A1
• Filed: 10/15/2008
• Published: 04/15/2010
• Est. Priority Date: 10/15/2008
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Athas, William C., Dorsey, John G.
• Granted Patent: US 8,244,296 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04B 1/036 Cooling arrangements
• CPC Class Codes: H04W 52/0251 using monitoring of local events, e.g. events related to user activity
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Methods and apparatus for dynamic thermal management and control within, e.g., small form-factor wireless devices such as laptop computers or cellular “smartphones”. In one embodiment, a thermal management system monitors the temperature (or other relevant criteria) for one or more components, and implements different operating states within the wireless transceiver (e.g., Wi-Fi™ or WiMAX transceiver) so as to both reduce thermal output and minimize disruption to the wireless link and/or user experience. In another embodiment, a wireless client may communicate with other clients, and/or access points, so as to cooperatively provide more options for thermal management. In addition, methods and apparatus employing “high performance” (e.g., high power output or high data rate) radios within aggressively small industrial designs are also disclosed.

Claims

1. A portable device, comprising:

a processing device coupled to at least one memory;

a wireless transceiver for communicating with other portable devices according to a specified wireless protocol; and

a plurality of heat generating components;

wherein said at least one memory comprises a plurality of instructions that when executed by said processing device;

determine when said wireless transceiver and at least a portion of said plurality of heat generating components, when operating in their respective operating states, cause a thermal threshold value to be exceeded; and

adjust one or more operating parameters for said wireless transceiver based at least in part on said determination.

2. The portable device of claim 1, wherein said plurality of instructions further comprises one or more instructions that when executed by said processing device, cause said adjustment of said one or more operating parameters until said thermal threshold value is no longer exceeded.

3. The portable device of claim 2, wherein said one or more operating parameters for said wireless transceiver are selected from the group consisting of:

a spatial multiplexing power save (SM PS) parameter, a channel bandwidth parameter, and a modulation and coding scheme (MCS) parameter.

4. The portable device of claim 2, wherein said operating parameters are adjusted in a predetermined order, said predetermined order based at least in part on the degree of disruption of communications on said wireless transceiver caused by each said parameter adjustment.

5. The portable device of claim 4, wherein said predetermined order comprises first adjusting a spatial multiplexing parameter.

6. The portable device of claim 4, wherein said predetermined order comprises first adjusting at least one of modulation type and channel coding.

7. The portable device of claim 1, wherein said plurality of instructions further comprises one or more instructions that when executed by said processing device, determine whether a modulation and coding scheme (MCS) index exceeds a threshold index value.

8. The portable device of claim 7, wherein said plurality of instructions further comprises one or more instructions that when executed by said processing device, reduces said MCS index when said threshold index value and said thermal threshold value are both exceeded.

9. The portable device of claim 8, wherein said plurality of instructions further comprises one or more instructions that when executed by said processing device, adjust one or more of said operating parameters until:

(i) said thermal threshold value is no longer exceeded and (ii) said MCS index is below said index threshold value.

10. The portable device of claim 9, wherein said operating parameters are adjusted in a predetermined order, said predetermined order based at least in part on a parameter relating to the level of disruption for communications on said wireless transceiver.

11. The portable device of claim 1, wherein said operating parameters are adjusted in a predetermined order, said predetermined order comprising adjusting a channel bandwidth parameter after adjusting a spatial multiplexing parameter.

12. The portable device of claim 1, wherein said processing device comprises a microcontroller, and said wireless transceiver comprises a transceiver compliant with IEEE Std. 802.11n.

13. A portable computerized device, comprising:

a digital processor;

a wireless transceiver having a power amplifier having a first state, said first state comprising a first power output, and one or more second states having respective power outputs that are each less than said first output; and

a thermal management system in operative communication with said wireless transceiver, said thermal management system adapted to operate said wireless transceiver;

(i) within said first state for at least bursts; and

(ii) within one or more of said second states when said thermal management system indicates that a thermal condition exists within said device that has exceeded a prescribed threshold.

14. The portable device of claim 13, wherein said power amplifier of said wireless transceiver is disposed within an enclosure of said device such that if operated in said first state continuously in conjunction with operation of said device, at least one component of said wireless device or transceiver would overheat.

15. The portable device of claim 14, wherein said first state comprises an output power of at least approximately 22 dBm.

16. The portable device of claim 14, wherein said thermal management system operates said wireless transceiver within said one or more of said second states according to at least one prescribed hierarchy of operational modes.

17. The portable device of claim 16, wherein said at least one prescribed hierarchy of operational modes comprises:

a first hierarchy organized substantially based on disruptive effect on a communication channel of said transceiver; and

a second hierarchy organized substantially based on accelerated reduction of temperature as compared to that of said first hierarchy.

18. A portable computerized device, comprising:

a digital processor;

a wireless transceiver having a power amplifier and a plurality of operating states, each of said states having a different combination of output power from said amplifier and data rate over a wireless channel; and

a thermal management system in operative communication with said wireless transceiver, said thermal management system adapted to operate said wireless transceiver in one of said plurality of states based on;

(i) a control input, and (ii) obeying at least one thermal criteria of said device.

19. The portable device of claim 18, wherein said control input comprises a user input received via a user interface, said user input specifying at least the desired relative importance of range capability to data rate.

20. The portable device of claim 19, wherein said user interface comprises a user interface that permits said user to input said desired relative importance graphically.

21. The portable device of claim 18, wherein said control input comprises an input received from logic within said device which automatically determines a desired relationship between range capability and data rate.

22. The portable device of claim 18, wherein said thermal management system further comprises a plurality of hierarchies of operational modes, said plurality comprises:

a first hierarchy organized substantially based on disruptive effect on a communication channel of said transceiver; and

a second hierarchy organized substantially based on accelerated reduction of temperature as compared to that of said first hierarchy;

wherein one or more of said hierarchies are implemented by said thermal management system if said at least one thermal criterion is exceeded.

23. The portable device of claim 18, wherein said thermal management system is further adapted to select a different one of said plurality of states if said at least one thermal criteria is exceeded, said different one of said states being selected so as to reduce heat generation within at least said power amplifier.