PATENT DOCUMENT

Publication Number: US-9936343-B2
Application Number: US-201615159306-A
Country: US
Kind Code: B2

Title: Wi-Fi process

Abstract:
A method and apparatus for a wireless device that can adapt a rate of related wireless network unit scans for adjacent networks is disclosed. In one embodiment, the wireless device can include a wireless network unit and a co-located geo-location signal receiver, and a processor. The processor can determine the position and speed of the wireless device from data received from the geo-location signal receiver. The processor can configure the wireless network unit to adapt the rate of related wireless network scans based upon determined speed and position. In one embodiment, the wireless network unit scans can be wireless scans for other nearby networks for roaming or location based services.

Claims:
What is claimed is: 
     
       1. A method, comprising:
 by a wireless device, performing operations for:
 receiving location signals that indicate positions of the wireless device; 
 determining a speed of the wireless device based at least in part on the location signals; 
 altering a period of time between wireless network scans made by the wireless device based at least in part on the speed of the wireless device, wherein the period of time between wireless network scans is increased in response to the speed of the wireless device being greater than a first speed; and 
 maintaining the period of time between wireless network scans in response to the speed of the wireless device being less than the first speed. 
 
 
     
     
       2. The method of  claim 1 , wherein the period of time between wireless network scans is increased in response to the speed being less than a second speed. 
     
     
       3. The method of  claim 1 , wherein the period of time between wireless network scans is decreased in response to the speed being greater than a second speed and less than the first speed. 
     
     
       4. The method of  claim 1 , wherein receiving the location signals comprises receiving the location signals in a geo-location signal receiver in the wireless device. 
     
     
       5. The method of  claim 1 , wherein the wireless network scans comprise location scans. 
     
     
       6. The method of  claim 1 , wherein the wireless network scans comprise roam scans. 
     
     
       7. The method of  claim 1 , wherein the wireless network scans comprise scans based at least in part on an IEEE 802.11 specification. 
     
     
       8. A wireless device, comprising:
 a network unit configured to perform operations for wireless network scans; 
 a geo-location signal receiver configured to:
 receive location signals that indicate a position of the wireless device; and 
 determine a change of the position of the wireless device based at least in part on the location signals; and 
 
 a processor configured to:
 decrease a period of time between network scans performed by the network unit in response to the change of position being greater than a first threshold; and 
 increase the period of time between wireless network scans in response to the change of position being less than a second threshold. 
 
 
     
     
       9. The wireless device of  claim 8 , wherein the period of time between wireless network scans remains unchanged in response to the change of position being less than the first threshold and greater than the second threshold. 
     
     
       10. The wireless device of  claim 9 , wherein the wireless network scans comprise scans based at least in part on an IEEE 802.11 wireless specification. 
     
     
       11. The wireless device of  claim 8 , further comprising:
 a motion sensor configured to detect motion of the wireless device, wherein the processor is further configured to adapt the period of time between the network scans based at least in part on the detected motion. 
 
     
     
       12. The wireless device of  claim 8 , wherein the wireless network scans comprise location scans. 
     
     
       13. The wireless device of  claim 8 , wherein the wireless network scans comprise roam scans. 
     
     
       14. A method comprising:
 receiving location signals at a mobile wireless device; 
 determining a change of position of the mobile wireless device based at least in part on the location signals; 
 decreasing a period of time between network scans in response to the change of position being greater than a first threshold; and 
 increasing the period of time between the network scans in response to the change of position being less than a second threshold. 
 
     
     
       15. The method of  claim 14 , wherein receiving the location signals comprises receiving the location signals at a geo-location signal receiver in the mobile wireless device. 
     
     
       16. The method of  claim 14 , wherein the network scans comprise roam scans. 
     
     
       17. The method of  claim 14 , wherein the network scans comprise location scans. 
     
     
       18. The method of  claim 14 , wherein the period of time between the network scans remains unchanged in response to the change of position being less than the first threshold and being greater than the second threshold. 
     
     
       19. The method of  claim 14 , wherein the change of position indicates a displacement of the mobile wireless device in relation to a predetermined distance. 
     
     
       20. The method of  claim 14 , further comprising:
 receiving motion data from a motion sensor of the mobile wireless device; and 
 increasing the period of time between the network scans in response to the motion data of the mobile wireless device indicating no motion.

Description:
RELATED APPLICATIONS 
     The instant application is a continuation of and hereby claims priority to U.S. application Ser. No. 14/449,972, titled “Wi-Fi Process,” filed Aug. 1, 2014, now U.S. Pat. No. 9,357,478, which is a continuation of U.S. application Ser. No. 13/396,226, titled “Wi-Fi Process,” filed on Feb. 14, 2012, now U.S. Pat. No. 8,805,360, all of which are incorporated by reference herein in their entireties. 
    
    
     BACKGROUND 
     Field of the Described Embodiments 
     The described embodiments relate generally to saving power in wireless devices. In particular, methods to adapt wireless network scans are described. 
     Related Art 
     Wireless devices have increased in complexity and capability since they have become first established. Early wireless devices were only able to handle voice communication though a cell phone network. Wireless device designs now include circuitry to enable access to alternative data networks such as networks governed by one of the many versions of the IEEE 802.11 specification. The wireless device user now can access internet data through either the cell phone network or the alternative data network. Data access through the alternative data network may be less costly compared to the cell phone network. Also, depending on cellular signal quality metrics at the users&#39; location, data throughput may be enhanced on the alternative network. 
     IEEE 802.11 networks are often serviced by access points (APs). A typical AP may only cover a range of roughly 2,000 square feet. When more coverage is required, multiple APs can be deployed. A wireless device currently connected to an AP can continually scan for other wireless channels so that as the user moves about, the wireless device can establish a connection to other APs if and when the current connection degrades. Such continual scans, however, can be a drain on the battery of the wireless device. 
     While simply increasing the period between scans can save power, the less frequent scans can make the wireless device less responsive and degrade the user experience. 
     Therefore, what is desired is a way to adapt the scanning rates for wireless networks to reduce power consumption and enhance the user experience. 
     SUMMARY OF THE DESCRIBED EMBODIMENTS 
     This paper describes various embodiments that relate to a wireless device, in particular methods and apparatus to adapt scanning periods of the wireless device. 
     In one embodiment, a method for adapting scanning periods of a wireless device can include the steps of receiving location signals with a location signal receiver, determining a change in position of the wireless device and altering a period of time between network scans in accordance with the change of position of the wireless device. In one embodiment, the location receiver can be a geo-location receiver that can be co-located with the wireless device. The network scanning periods can be adapted when the change of position indicates a displacement is greater than or less than a predetermined distance. In one embodiment, the network scans can be roaming scans that can identify other wireless networks that may be available for use and location scans that can be used to provide location based services. 
     A wireless device than can adapt network scanning periods is described. The wireless device can include a wireless network unit for transferring data, a co-located geo-location signal receiver unit for receiving geo-location signals and determining the position of the wireless device and a processor configured to adapt network scanning periods when the position of the wireless device changes. 
     A method for saving power in a mobile wireless device can include the steps of receiving a location signal at the wireless device, determining a change of position of the mobile wireless device from the location signals, determining a speed of the mobile wireless device when a change of position is detected and adapting the scanning periods based upon the determined speed. In one embodiment, the scanning periods can be adapted when the determined speed is greater than a first predetermined speed. 
     Other aspects and advantages of this disclosure will become apparent from the following detailed description taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the described embodiments. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The described embodiments and the advantages thereof may best be understood by reference to the, following description taken in conjunction with the accompanying drawings. These drawings in no way limit any changes in form and detail that may be made to the described embodiments by one skilled in the art without departing from the spirit and scope of the described embodiments. 
    
    
     
       DETAILED DESCRIPTION 
         FIG. 1  is a diagram showing one example of a wireless system. 
         FIG. 2  is a block diagram of one embodiment of a wireless device in accordance with the specification. 
         FIG. 3  is a diagram showing one embodiment of an adaptive scanning wireless system. 
         FIG. 4  is a flowchart of method steps for adapting network scanning rates, according to one embodiment of the specification. 
         FIG. 5  is a flowchart of method steps for adapting network scanning rates, according to one embodiment of the specification. 
         FIG. 6  is a diagram showing another embodiment of an adaptive scanning wireless system. 
         FIG. 7  is a flowchart of method, steps for adapting network scanning rates, according to one embodiment of the specification. 
         FIG. 8  is a flowchart of method steps for adapting network scanning rates, according to one embodiment of the specification. 
         FIG. 9  is a diagram showing another embodiment of an adaptive scanning wireless system. 
         FIG. 10  is a flowchart of method steps for adapting network scanning rates, according to one embodiment of the specification. 
         FIG. 11  is a diagram showing another embodiment of an adaptive scanning wireless system. 
         FIG. 12  is a flowchart of method steps for adapting network scanning rates, according to one embodiment of the specification. 
         FIG. 13  is a flowchart of method steps for adapting network scanning rates, according to another embodiment of the specification. 
         FIG. 14  is another block diagram of a wireless device, according to one embodiment of the specification. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Representative applications of methods and apparatus according to the present application are described in this section. These examples are being provided solely to add context and aid in the understanding of the described embodiments. It will thus be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the described embodiments. Other applications are possible, such that the following examples should not be taken as limiting. 
     In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting; such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments. 
     Wireless devices can include a cell phone modem, a wireless network unit and a geo-location signal receiver. Geo-location signal receivers can often be referred to as Global Navigation Satellite System (GNSS) receiver and can receive and decode the geo-location signals from one or more geo-location systems. The cell phone modem can be used for voice and data. The wireless network unit can be used to connect to a wireless network and the geo-location signal receiver can be used to receive, recover and decode geo-location (i.e., GNSS satellite) signals and provide location data. 
     Wireless devices, especially when they are mobile wireless devices, can perform roam scans and location scans. Roam scans can be used to determine presence and operating characteristics of wireless networks, particularly those wireless networks that may not be currently used by the wireless device. These roam scans can be used to create a list of alternative wireless networks that can be used should signal metrics of a currently used wireless network degrade. 
     Location scans, in contrast, can be used to support location based services for the user. A location scan can be made to determine signal characteristics of access points (APs) within signal range of the wireless device. Often, using a location server, the signal characteristics can be used to locate the wireless device and provide location based services such as location based advertisements or messages. 
     Roam scans and location scans can occur with a regular period. One drawback of these periodic scans is that they can present an increased power drain on a battery of the wireless device. However, by adaptively changing the roam scan and location scan periods, the power drain can be reduced. 
     By advantageously using geo-location signal derived position data, the period between roam scans and/or location scans can be adapted to, in one embodiment, reduce power consumption. In another embodiment, the period between roam scans and/or location scans can be adapted to improve the user experience. 
       FIG. 1  is a diagram showing one example of a wireless system  100 . The system  100  can include a wireless device  102 , access points  104 ,  106  and  108 , a network  110 , a location server  112  and a cell tower  120 . The wireless device  102  can include circuitry to enable a connection between the wireless device  102  and the cell tower  120  and between the wireless device  102  and the access points  104 ,  106  and  108 . Examples of wireless devices  102  can include smartphones, personal digital assistants and laptops. 
     The wireless device  102  can connect to the cell tower  120  to transfer data to and from a cell phone network (not shown). The wireless device  102  can also connect to at least one of the APs within the wireless system  100 . In the example of  FIG. 1 , the wireless device  102  is connected to AP  108 . The coverage area of an AP is schematically represented by a circle drawn around the AP. In this example, AP  104  has coverage  105 , AP  106  has coverage  107  and AP  108  has coverage  109 . 
     The wireless device  102  can move beyond the coverage area  109  of the AP  108 . The wireless device  102  can maintain a list of alternate APs that may be used if, for example, signal strength should fall below a predefined level. In order to maintain the list of alternate APs the wireless device  102  can perform periodic roam scans to determine the presence and signal characteristics of other APs that are relatively near the wireless device  102 . In one embodiment, a roam scan can include probe request and probe response frames that can be sent on wireless channels in accordance with IEEE 802.11 standards. 
     The wireless device  102  can also perform location scans to enable location based services. In one embodiment, location scans can determine the presence, and to some extent the proximity of nearby APs. Similar to a roam scan, in one embodiment, a location scan can include probe request and probe response frames that can be sent on wireless channels in accordance with IEEE 802.11 standards. The results of the probe responses, including signal characteristics such as signal strength can be sent to the location server  112 . The location server  112  can examine the results of the locations scan and determine the presence of any services for the user such as location based advertisements or messages. In one embodiment, the location server  112  can provide this data through the network  110  and the AP  108  to the wireless device  102 . 
     Both the roam scans and the location scans can occur periodically. The periods of the roam and location scans need not match. Also, some scans can be context sensitive. For example, location scans can be suspended altogether depending on other activities from the user on the wireless device  102 . For example, a user can choose to block location based advertisements eliminating the need for location scans. 
       FIG. 2  is a block diagram of one embodiment of a wireless device  200  in accordance with the specification. The wireless device  200  can include a wireless network engine  202 , a geo-location signal receiver  204 , a motion sensor  220 , and a processor  206 . The wireless network engine  202  can be coupled to the processor  206  and can be configured to transmit and receive wireless data according to a wireless protocol. In one embodiment, the wireless network engine  202  can be configured to transfer data to and from APs according to an IEEE 802.11 standard through antenna  210 . 
     The geo-location signal receiver  204  can receive geo-location signals, such as satellite positioning signals through antenna  212 . In one embodiment, the geo-location signal receiver  204  can be co-located with the wireless network engine  202 . In another embodiment, the geo-location signal receiver  204  may be realized separately, but co-located with the wireless device  200 . The geo-location signals can be geo-location signals such as Global Positioning System (GPS) signals broadcast from the U.S. based navigation satellite system, GLObal NAvigational Satellite System a (GLONASS) signals broadcast from the Russian based navigation satellite system or other similar systems. The geo-location signal receiver  204  can be coupled to the processor  206  and provide location data derived from the received satellite signals. 
     In one embodiment, the processor  206  can include a location engine  208 . The location engine  208  can examine the location data from the geo-location signal receiver  204  and determine movement dynamics (speed and direction) of the wireless device  200 . The location data from the geo-location signal receiver  204  can include position information of the wireless device  200 . In one embodiment, the location data can include latitude and longitude information. In another embodiment, the location data can include a relative position of the wireless device  200 . The location engine  208  can also monitor the geo-location signal receiver  204  and determine whether navigation satellites have been acquired and whether the geo-location signal receiver  204  can continue to track navigation satellites. If the geo-location signal receiver  204  can track the navigation satellites, then the geo-location signal receiver  204  is said to have be in a locked condition. Additionally, the motion sensor  220  can be coupled to the processor  206  and can provide motion information related to the wireless device  200  to the processor  206 . 
       FIG. 3  is a diagram showing one embodiment of an adaptive scanning wireless system  300 . The system  300  can include a wireless device  200 , access points  310  and  312  and geo-location satellites  320   a ,  320   b ,  320   c , and  320   c . The wireless device  200  can be similar to the wireless device  200  of  FIG. 2  and include both a wireless network engine and a geo-location signal receiver. AP  310  can have a coverage area shown by circle  311  and AP  312  can, have a coverage area shown by circle  314 . 
     The wireless device  200  can receive geo-location satellite signals from the geo-location satellites  320   a - 320   d , and the geo-location signal, receiver  204  included within the wireless device  301  can determine the position of the wireless device  200 . Although four geo-location satellites are shown here, persons skilled in the art can appreciate that the position of wireless device  200  can be determined with fewer than or more than four geo-location satellites. Using the determined position, the wireless device  200  can determine if the wireless device  200  has been or is moving, and moreover, if the wireless device  200  has moved less than a predetermined distance. If the wireless device  200  has moved less than a predetermined distance, then the wireless device  200  can be assumed to be stationary or moving a such a slow rate that the wireless device  200  is substantially stationary. For example, wireless device can begin in position  301  (shown with dashed lines in  FIG. 3 ) and move to position  303 . In the example, the wireless device  200  has little or no motion detected and remains within coverage area  311 . 
     When the wireless device  200  is stationary or substantially stationary, the period of the roam scans can be increased (roam scans can be performed less frequently). As described above, roam scans can be used to determine the presence and availability of alternate wireless networks that can be used as the wireless device  200  moves out of a service area of a currently used wireless network. Since the wireless device  200  is effectively still, or moving very slowly, roam scans can be unnecessary, given that switching to an alternate wireless network is relatively unlikely. 
     In a similar manner, when the wireless device  200  is stationary or substantially stationary, the period of the location scans can advantageously be increased (location scans can be performed less frequently). Provided that an earlier location scan has completed, more recent location scans will not provide any new or useful information. 
     The wireless device  200  can also determine motion through, the motion sensor  220  within the wireless device  200 . If the wireless device  200  determines that no or substantially no motion has occurred, then the roam and location scans can be adapted as described earlier (roam and location scans can be performed less frequently). 
       FIG. 4  is a flowchart  400  of method steps for adapting network scanning rates, according to one embodiment of the specification. Persons skilled in the art will understand that any system configured to perform the method steps in any order is within the scope of this description. 
     As shown in  FIG. 4 , the method begins in step  402  where the scanning periods for roam scans and location scans are set to an initial period. In one embodiment the initial scan periods can be 45 seconds. In another embodiment, the scan period can be a telescopic period. For example, the initial period may start out at 1 second, then may increase to a maximum. One telescopic sequence can be 1, 3, 5, 10 and 30 seconds. The initial scan periods can be any period, in particular the selected period times can provide an acceptable rate of determining the presence of new networks and reacting to them. In another embodiment, the initial scan periods can be inherited as the method begins. That is, the scan period that was previously determined or used when the method began, can be used as the initial scan period. 
     In step  404 , the wireless device  200  can receive geo-location signals. In one embodiment the geo-location signals can be geo-location satellite signals. In step  405 , the geo-location signal receiver  204  can determine a position of the wireless device  200  from the received geo-location signals. In step  406 , the wireless device  200  determines if the position of the wireless device  200  has changed. If the position of the wireless device  200  has not changed then the method returns to step  404 . The sequence of steps  404 ,  405  and  406  can be referred to as tracking, geo-location signals. Tracking, can be a continual or periodic reception and processing of geo-location signals to update a determined position. Returning to step  406 , if the position of the wireless device  200  has changed, then the method proceeds to step  422 . 
     In step  422 , the wireless device  200  determines if the wireless device  200  has moved (been displaced) less than a first predetermined distance. In one embodiment, the first predetermined distance can be a user adjustable amount. In another embodiment, the first predetermined distance can be 1 meter. If the wireless device  200  has moved less than the first predetermined distance, then in step  424  the period for roam scans and location scans can be increased (roam and location scans can be performed less frequently then as set forth in step  402 ) and the method ends. In one embodiment, the method of  FIG. 4  can be modified such than instead of terminating, the method can, instead, loop back, to step  402 . The addition of such a loop can advantageously allow for continuous rate adaptation. 
     Since the determined movement of the wireless device  200  is less than a movement threshold determined by the first predetermined distance, the wireless device  200  has not likely moved beyond the coverage range of a currently connected AP. In this case, the period of the roam and location scans can be increased. Increasing the roam and location scan periods can advantageously reduce power consumption of the wireless device  200 . 
     Many wireless devices include a motion sensor that may be advantageously be used to adapt wireless network scans.  FIG. 5  is a flowchart  500  of method steps for adapting network scanning rates, according to one embodiment of the specification. The method being in step  502  where the scanning periods for roam scans and location scans are set to an initial period. In step  504 , motion is monitored by the, motion sensor  220 . If motion is detected, then the method ends. If on the other hand, no motion is detected, then in step  506  the period is increased for roam and location scans (roam and location scans are performed less frequently then as set forth in step  502 ) and the method ends. In one embodiment, the method of  FIG. 5  can be modified such than instead of terminating, the method can, instead, loop back to step  502 . The addition of such a loop can advantageously allow for continuous rate adaptation. Although the method  500  describes a motion sensor, other sensors can be used. For example, an accelerometer or shock sensor may be used in lieu of or with the motion sensor  220 . 
       FIG. 6  is a diagram showing another embodiment of an adaptive scanning wireless system  600 . The system  600  can include a wireless device  200 , access points  610  and  612  and geo-location satellites  320   a ,  320   b ,  320   c , and  320   c.    
     As shown in  FIG. 6 , AP  610  can have a coverage area  611  as shown. AP  612  can be a second AP with a coverage area  613 . As shown, the coverage areas  611  and  613  do not overlap. Wireless device  200  can be moved from a first position to a second position. The first position is shown as  650  (the wireless device is  200  shown with dashed lines) and, the second position is shown as  651  (the wireless device  200  is shown with solid lines). A shown, the amount of displacement can be greater than the coverage area of an AP, such as coverage area  611 . When the wireless device  200  is displaced a distance greater than the coverage area of an AP, the wireless device  200  can advantageously reduce the period of roam scans to enable a faster discovery of other APs that can connect to the wireless device  200 . Reducing roam scan periods (performing more frequent roam scans) can allow an adaptation of the scan rate, particularly if the scan rate was previously reduced as was described above in  FIG. 4 or 5  enhancing responsiveness of wireless device  200 . 
       FIG. 7  is a flowchart  700  of method steps for adapting network scanning rates, according to one embodiment of the specification. The method begins in step  702  where the scanning periods for roam scans and location scans are set to an initial period. In one embodiment the initial scan periods can be 45 seconds. In another embodiment the scan period can be a telescopic period as described above in  FIG. 4 . In yet another embodiment, the initial scan period can be inherited as the method begins. That is, the scan period that was previously determined when the method began, can be used as the initial scan period. That is, the scan period that was previously determined or used when the method began, can be used as the initial scan period. 
     In step  704 , the wireless device  200  can receive geo-location signals. In one embodiment the geo-location signals can be geo-location satellite signals. In step  705 , the geo-location signal receiver  204  can determine a position of the wireless device  200  from the received geo-location signals. In step  706 , the wireless device  200  determines if the position of the wireless device  200  has changed. If the position of the wireless device  200  has not changed then the method returns to step  704 . The sequence of steps  704 ,  705  and  706  can be referred to as tracking geo-location signals. Tracking can be a continual or periodic reception and processing of geo-location signals to update a determined position. Returning to step  706 , if the position of the wireless device  200  has changed, then the method proceeds to step  722 . 
     In step  722 , the wireless device  200  determines if the wireless device  200  has moved (been displaced) more than a second predetermined distance. In one embodiment, the second predetermined distance can be related to the coverage area of an AP. In another embodiment, the second predetermined distance can be user selectable. A user selectable distance can be useful as an adjustment to compensate for an operating environment. For example, some environments can be relatively open and free from wireless signal blockers. Such environments can have larger AP coverage areas. On the other hand, if some environments have relatively more signal blockers or lower power APs, then the user selectable distance can be decreased. 
     If in step  722  the wireless device  200  has moved, more than a second predetermined distance, then in step  724  the period of the roam scans is decreased (roam scans can be performed more frequently then as set forth in step  702 ). If, on the other hand, the wireless device  200  has not moved more than a second predetermined distance, then the method ends. In one embodiment, the method of  FIG. 7  can be modified such than instead of terminating, the method can, instead, loop back to step  702 . The addition of such a loop can advantageously allow for continuous rate adaptation. 
       FIG. 8  is a flowchart  800  of method steps for adapting network scanning rates, according to one embodiment of the specification. This method can advantageously combine the methods set forth by  FIGS. 4 and 7 . The method begins in step  802  where the scanning periods for roam scans and location scans are set to an initial period. In one embodiment the initial scan periods can be 45 seconds. In another embodiment the scan, period can be a telescopic period as described above in  FIG. 4 . 
     In step  804 , the wireless device  200  can receive geo-location signals. In one embodiment the geo-location signals can be geo-location satellite signals. In step  805 , the geo-location signal receiver  204  can determine a position of the wireless device  200  from the received geo-location signals. In step  806 , the wireless device  200  determines if the position of the wireless device  200  has changed. If the position of the wireless device  200  has not changed then the method returns to step  804 . The sequence of steps  804 ,  805  and  806  can be referred to as tracking geo-location signals. Tracking can be a continual or periodic reception and processing of geo-location signals to update a determined position. Returning to step  806 , if the position of the wireless device  200  has changed, then the method proceeds to step  820 . 
     In step  820 , the wireless device  200  determines if the wireless device  200  has moved more than a first predetermined distance. In one embodiment, the first predetermined distance is similar to the predetermined distance as described in  FIG. 7 . If the distance between the first and second position is greater than the first predetermined distance, then in step  822  the period between roam scans can be decreased (roam scans can be performed more frequently then as set forth in step  802 ) and the method ends. 
     If, on the other hand, the wireless device  200  has moved less than the first predetermined distance, then in step  824  the wireless device  200  determines if the wireless device  200  has moved less that a second predetermined distance. In one embodiment, the second predetermined distance can be similar to the predetermined distance described in  FIG. 4 . If the wireless device  200  has moved less than the second predetermined distance, then in step  826  the period between both roam and location scans can be increased (roam and location scans can be performed less frequently then as set forth in step  806 ) and the method ends. If, in step  824 , the distance between the first and second positions is not less than the second predetermined distance, then the method ends. In one embodiment, the method of  FIG. 8  can be modified such than instead of terminating, the method can, instead, loop back to step  802 . The addition of such a loop can advantageously allow for continuous rate adaptation. 
       FIG. 9  is a diagram showing another embodiment of an adaptive scanning wireless system  900 . The system  900  can include a wireless device  200 , access point regions  910 ,  912  and  914  and geo-location signal  320   a - 320   d . Access point coverage regions  910 ,  912  and  914  illustrate a coverage area that can be serviced by an associated access point (APs are not shown for clarity). 
     Wireless device  200  is shown in a first position  920  and moves to a second position  922 . To help illustrate this motion, the wireless device  200  is drawn with dashed lines at the first position  920  and solid lines at the second position  922 . 
     As described above, the periodicity of roam scans can be adapted to help enhance the user experience in the wireless device  200 . The exemplary scenario illustrated in  FIG. 9  shows the wireless device  200  in motion. In this case, the wireless device  200  can move at a rate that is greater than a walking speed. In one embodiment, this speed is 8 miles per hour. In another embodiment, the speed can a user set parameter. Since the wireless device  200  moves faster than a walking speed, the wireless device  200  does not linger in an AP coverage area for an extended period of time. The wireless device  200  can be more responsive by becoming aware of the presence of other APs while the wireless device  200  is in motion. Thus, the user experience can be improved by performing roam scans more often. 
       FIG. 10  is a flowchart  1000  of method steps for adapting network scanning rates, according to one embodiment of the specification. The method begins in step  1002  where the scanning periods for roam scans and location scans are set to an initial period. In one embodiment the initial scan periods can be 45 seconds. In another embodiment the scan period can be a telescopic period as described above in  FIG. 4 . 
     In, step  1004 , the wireless device  200  can receive geo-location signals. In one embodiment the geo-location signals can be geo-location satellite signals. In step  1005 , the geo-location signal receiver  204  can determine a position of the wireless device  200  from the received geo-location signals. In step  1006 , the wireless device  200  determines if the position of the wireless device  200  has clanged. If the position of the wireless device  200  has not changed then the method returns to step  1004 , The sequence of steps  1004 ,  1005  and  1006  can be referred to as tracking geo-location signals. Tracking can be a continual or periodic reception and processing of geo-location signals to update a determined position. Returning to step  1006 , if the position of the wireless device  200  has changed, then the method proceeds to step  1016 . 
     In step  1016 , the speed of the wireless device  200  is determined with location data from the geo-location signal receiver  204 . 
     in step  1018 , a speed of the wireless device  200  is compared to a predetermined speed. In one embodiment, this predetermined speed is faster than a walking speed. In another embodiment, the predetermined speed is 8 miles per hour. In yet another embodiment, the predetermined speed can be set by the user. If the speed of the wireless device  200  is greater than the predetermined speed, then in step  1020  the period of the roam scans is decreased (i.e., roam scans are performed more frequently than as set forth in step  1002 ) and the method ends. 
     If, on the other hand, in step  1018  the speed of the wireless device  200  is not greater than the predetermined speed, then the method proceeds to step  1024  and the periods of the roam and location scans are not changed and the method ends. In one embodiment, the method of  FIG. 10  can be modified such than instead of terminating, the method can, instead, loop back to step  1010 . The addition of such a loop can advantageously allow for continuous rate adaptation. 
       FIG. 11  is a diagram showing another embodiment of an adaptive scanning wireless system  1100 . The system  1100  can include a wireless device  200 , access point coverage regions  1110 ,  1112 ,  1114  and  1116  and geo-location satellites  320   a - 320   d . Access point coverage regions  1110 ,  1112 ,  1114  and  1116  illustrate a coverage area that can be serviced by an associated access point (APs are not shown for clarity). 
     Wireless device  200  is shown in a first position  1120  and moving to a second position  1122 . To help illustrate this motion, the wireless device  200  is drawn with dashed lines at the first position  1120  and solid lines at the second position  1122 . 
     Similar to  FIG. 9 ,  FIG. 11  illustrates a scenario when the wireless device  200  is moving, but in this exemplary example, the speed of the wireless device  200  is much greater than walking speed. In one embodiment, the speed of the wireless device  200  can be similar to the speed of a train or plane in motion. In another embodiment, the speed of the wireless device  200  can be greater than or equal to 50 miles per hour. When the wireless device  200  travels at such a speed, the wireless device  200  typically cannot completely receive wireless signals from nearby APs without error. At such rates of speed, the wireless device  200  travels quickly through AP regions (illustrated by the arrow in  FIG. 11 ). Since the probability is low that the wireless device  200  can correctly receive and decode wireless signals from the APs, the period of roam scans can advantageously be increased to reduce power consumption (roam and location scans can be performed less frequently). 
       FIG. 12  is a flowchart  1200  of, method steps for adapting network scanning rates, according to one embodiment of the specification. The method begins in step  1202  where the scanning periods for roam scans and location scans are set to an initial period. In one embodiment the initial scan periods, can be 45 seconds. In, another embodiment the scan period can be a telescopic period as described above in  FIG. 4 . 
     In step  1204 , the wireless device  200  can receive geo-location signals. In one embodiment the geo-location signals can be geo-location satellite signals. In step  1205 , the geo-location signal receiver  204  can determine a position of the wireless device  200  from the received geo-location signals. In step  1206 , the wireless device  200  determines if the position of the wireless device  200  has changed. If the position of the wireless device  200  has not changed then the method returns to step  1204 . The sequence of steps  1204 ,  1205  and  1206  can be referred to as tracking geo-location signals. Tracking can be a continual or periodic reception and processing of geo-location signals to update a determined position. Returning to step  1206 , if the position of the wireless device  200  has changed, then the method proceeds to step  1216 . 
     In step  1216 , a speed is determined of the wireless device  200  using location data from the, geo-location signal receiver  204 . 
     In step  1218 , the speed of the wireless device  200  is compared to a predetermined speed. In one embodiment, this predetermined speed is similar to a typical speed of travel for a train. In another embodiment, the predetermined speed can be 50 miles per hour. In yet another embodiment, the predetermined speed can be set by the user. If the speed of the wireless device  200  is greater than the predetermined speed, then in step  1220  the period of the roam scans is increased (roam scans are performed less frequently than as set forth in step  1202 ) and the method ends. If the speed of the wireless device  200  is less than the predetermined speed, then in step  1222  the periods of the roam and location scans are not changed and the method ends. 
     The methods described in the flowcharts of  FIG. 10  and  FIG. 12  can be combined to ease implementation. Since each individual method targets a distinct speed threshold, two different predetermined speeds can be used to implement the combined method. In one embodiment, the method of  FIG. 12  can be modified such than instead of terminating, the method can, instead, loop back to step  1210 . The addition of such a loop can advantageously allow for continuous rate adaptation. 
       FIG. 13  is a flowchart  1300  of method steps for adapting network scanning rates, according to another embodiment of the specification. The method begins in step  1302  where the scanning periods for roam scans and location scans are set to an initial period. In one embodiment the initial scan periods can be 45 seconds. In another embodiment the scan period can be a telescopic period as described above in  FIG. 4 . 
     In step  1304 , the wireless device  200  can receive geo-location signals. In one embodiment the geo-location signals can be geo-location satellite signals. In step  1305 , the geo-location signal receiver  204  can determine a position of the wireless device  200  from the received geo-location signals. In step  1306 , the wireless device  200  determines if the position of the wireless device  200  has changed. If the position of the wireless device  200  has not changed then the method returns to step  1304 . The sequence of steps  1304 ,  1305  and  1306  can be referred to as tracking geo-location signals. Tracking can be a continual or periodic reception and processing of geo-location signals to update a determined position. Returning to step  1306 , if the position of the wireless device  200  has changed, then the method proceeds to step  1316 . 
     In step  1316 , the speed is determined of the wireless device  200  using location data from the geo-location signal receiver  204 . In step  1318 , the speed of the wireless device  200  is compared to a first predetermined speed. In one embodiment, the first predetermined speed is similar to the predetermined speed described in step  1218  in flowchart  1200 . In another embodiment, the first predetermined speed is 55 miles per hour. If the speed of the wireless device  200  is greater than the first predetermined speed, then in step  1320 , the period of the roan scans are decreased (scans cat be performed more frequently than as set forth in step  1302 ) and the method ends. 
     On the other hand, if the speed of the wireless device  200  is not greater than the first predetermined speed, in step  1324 , the speed of the wireless device  200  is compared to a second predetermined speed. In one embodiment, the second predetermined speed, can be similar to the speed described in step  1018  in flowchart  1000 . In another embodiment, the second predetermined speed is 8 miles an hour. In yet another embodiment, the second predetermined speed is less than the first predetermined speed. If the speed of the wireless device  200  is greater than the second predetermined speed, then in step  1326  the period between roam scans is increased (the roam scans are performed less frequently) and the method ends. On the other hand, if in step  1324 , the speed of the wireless device  200  is not greater than the second predetermined speed, then in step  1328  the scan periods of the roam and location scans remain unchanged and the method ends. In one embodiment, the method of  FIG. 13  can be modified such than instead of terminating, the method can, instead, loop back to step  1310 . The addition of such a loop can advantageously allow for continuous rate adaptation. 
       FIG. 14  is another block diagram of a wireless device  1400 , according to one embodiment of the specification. The wireless device  1400  can include, without limitation, a processor  1410 , a battery  1412 , a display unit  1414 , a memory  1416 , a wireless network unit  1418 , a geo-location signal receiver  1420 , a motion sensor  1422  and an acceleration sensor  1424 . 
     The processor  1410  can be used to execute computer code stored in the memory device  1416 . The memory device  1416  can be random access memory (RAM), read only memory (ROM), a disc drive (HDD), a CD-ROM, a DVD or any other technically feasible data storage device. The battery  1412  cab be coupled to the processor  1410  and can provide power to the processor  1410  and other units within the wireless device  1400 . The display unit  1414  can be coupled to the processor  1410 . The processor  1410  can display user information and data on the display unit  1414 . 
     The wireless network unit  1418  can be coupled to the processor  1410 . The wireless network unit  1418  can transfer wireless network data with other wireless nodes such as wireless APs. In one embodiment, data received by the wireless unit  1418  can be processed by the processor  1410  and displayed on the display unit  1414 . The geo-location signal receiver  1420  can be coupled to the processor  1410  and can receive geo-location signals (such as GNSS satellite signals) and process the received signals. In one embodiment, the geo-location signal receiver  1420  can provide location data. The motion sensor  1422  and the acceleration sensor  1424  can be coupled to the processor  1410  and can provide motion and acceleration data. 
     The processor  1410  can configure the wireless network unit  1418  to increase or decrease the period of wireless network scans relative to an initial period setting of wireless network scans. The processor  1410  can increase and decrease the period of wireless network scans based upon location and tracking data from the geo-location signal receiver  1420 , motion data from the motion sensor  1422  and/or acceleration data from the acceleration sensor  1424 . 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the, computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in, a distributed fashion. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of specific embodiments are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the described embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.

Metadata:
Filing Date: 20160519
Publication Date: 20180403
Grant Date: 20180403
Priority Date: 20120214
Inventors: NAGARAJ SURESH
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W52/0229", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0254", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W64/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0229", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/3805", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/3805", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W52/0245", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W4/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0245", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W52/0254", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W84/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W4/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W52/0245", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W64/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0229", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04B1/3805", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W52/0254", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02B60/50", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W48/16", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W84/12", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W88/08", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W4/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y02D30/70", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 47747843