Energy efficient roaming of a mobile device

Abstract

Energy efficient roaming of a mobile device is described. The mobile device can include a sensor for sensing a motion of the mobile device to generate a sensor signal. A radio is capable of communicating with a wireless network. A processor activates the radio in the mobile device. The processor generates an environmental profile of the mobile device based at least on the sensor signal. A memory is coupled to the processor for storing the environmental profile. The processor deactivates the radio when the environmental profile indicates that the rate of motion of the mobile device is above a predetermined threshold for a first period of time. The processor reactivates the deactivated radio when the environmental profile indicates that the rate of motion of the mobile device is below the predetermined threshold for a second period of time.

What is claimed is: 
     
       1. A method comprising:
 activating a radio in a mobile device by a processor of the mobile device, the radio configured to communicate with a wireless network; 
 provisioning the mobile device with at least one pre-determined environment profile, wherein the at least one pre-determined environment profile comprises conditions under which the radio is unable to connect with the wireless network; 
 sensing, by a sensor of the mobile device, an environmental condition of the mobile device to generate a sensor signal; 
 generating, by the processor of the mobile device, an environmental profile of the mobile device based at least on the sensor signal; 
 comparing, by the processor of the mobile device, the environmental profile of the mobile device with the at least one pre-determined environmental profile; 
 deactivating, by the processor of the mobile device, the activated radio when the comparing indicates that the environmental profile is above a threshold of the pre-determined environmental profile for a first period of time; and 
 reactivating, by the processor of the mobile device, the deactivated radio when the comparing indicates that the environmental profile is below a the threshold of the pre-determined environmental profile for a second period of time, 
 wherein the sensor is an altimeter and the wireless network comprises an IEEE 802.11 wireless communication system, and wherein the environmental profile further comprises a rate of change in an altitude of the mobile device, and wherein the threshold comparing indicates that the mobile device is within a building based on the altitude, whereupon the deactivated radio is activated reactivated. 
 
     
     
       2. The method of  claim 1 , wherein the wireless network comprises an IEEE 802.11 wireless communication system, and wherein the environmental condition includes a speed of the mobile device, wherein the threshold comparing further indicates that the mobile device is within a moving vehicle, whereupon the radio is deactivated. 
     
     
       3. The method of  claim 2 , wherein the motion speed is sensed using a motion sensor in the mobile device. 
     
     
       4. The method of  claim 1  further comprising storing the environmental profile in a memory of the mobile device. 
     
     
       5. The method of  claim 1 , wherein the environmental condition is based on at least one of a velocity, acceleration, vibration, rotation, and tilt of the mobile device. 
     
     
       6. The method of  claim 1 , wherein the wireless network comprises an IEEE 802.11 wireless communication system. 
     
     
       7. The method of  claim 1 , further comprising periodically reactivating the radio during the first period of time to attempt to communicate with the wireless network. 
     
     
       8. The method of  claim 1 , wherein the first period of time is different than the second period of time. 
     
     
       9. The method of  claim 1 , further comprising deactivating the radio when the environmental profile indicates that the mobile device is traveling in a vehicle. 
     
     
       10. The method of  claim 1 , further comprising manually overriding the sensor signal to reactivate the radio when the radio is deactivated. 
     
     
       11. A mobile device comprising:
 a sensor sensing an environmental condition of the mobile device to generate a sensor signal; 
 a radio configured to communicate with a wireless network; and 
 a memory coupled to a processor and storing at least one pre-determined environmental profile, wherein the at least one pre-determined environmental profile comprises conditions under which the radio is unable to connect with the wireless network; 
 the processor configured to:
 activate the radio in the mobile device; 
 generate an environmental profile of the mobile device based at least on the sensor signal; 
 compare the environmental profile of the mobile device with the at least one predetermined environmental profile; 
 de-activate the activated radio when the comparing indicates that the environmental profile is above a threshold of the pre-determined environmental profile for a first period of time; and 
 re-activate the deactivated radio when the comparing indicates that the environmental profile is below a the threshold of the pre-determined environmental profile for a second period of time, 
 
 wherein the sensor is an altimeter and the wireless network comprises an IEEE 802.11 wireless communication system, and wherein the environmental profile further comprises a rate of change in an altitude of the mobile device, and wherein the threshold comparing indicates that the mobile device is within a building based on the altitude, whereupon the deactivated radio is activated reactivated. 
 
     
     
       12. The mobile device of  claim 11 , wherein the wireless network comprises an IEEE 802.11 wireless communication system, and wherein the environmental condition includes a speed of the mobile device, wherein the threshold comparing further indicates that the mobile device is within a moving vehicle, whereupon the radio is deactivated. 
     
     
       13. The mobile device of  claim 11 , wherein the environmental condition is based on at least one of a velocity, acceleration, vibration, rotation, and tilt of the mobile device. 
     
     
       14. The mobile device of  claim 11 , wherein the sensor further comprises at least one of an accelerometer and a gyroscopic sensor. 
     
     
       15. The mobile device of  claim 11 , wherein the processor periodically reactivates the radio during the first period of time to attempt to communicate with a wireless network. 
     
     
       16. The mobile device of  claim 11 , wherein the first period of time is different than the second period of time. 
     
     
       17. The mobile device of  claim 11 , wherein the wireless network comprises an IEEE 802.11 wireless communication system. 
     
     
       18. The mobile device of  claim 11 , wherein the radio is deactivated when the environmental profile indicates that the mobile device is traveling in a vehicle. 
     
     
       19. The mobile device of  claim 11 , further comprising a user interface for communicating an instruction to the processor. 
     
     
       20. The mobile device of  claim 19 , wherein the instruction comprises manually overriding the sensor signal to reactivate the radio when the radio is deactivated.