PATENT DOCUMENT

Publication Number: US-10042035-B2
Application Number: US-201213609830-A
Country: US
Kind Code: B2

Title: System and method for tile-based reduction of access point location information

Abstract:
Embodiments of a system and method for tile-based reduction of access point location information are described. Embodiments may reduce a set of network access points and respective locations to generate a reduced set. For instance, embodiments may include parsing a representation of a geographic region into multiple tiles. Embodiments may also include, for each sub-area or “bucket” of multiple buckets that make up a given tile, evaluating the set of network access points and respective locations to identify network access points residing in that bucket, and based on a ranking of the network access points in that bucket, eliminating at least some network access points of that sub-area from the reduced set. Embodiments may also include, for each sub-tile of multiple sub-tiles of the given tile, assigning within the reduced set a common location to multiple access points residing within different locations of that sub-tile.

Claims:
What is claimed is: 
     
       1. A method comprising:
 receiving network access point information for a plurality of network access points located in a region, wherein the network access point information comprises location information for each network access point of the plurality of network access points; 
 parsing the region into multiple tiles and for at least one of the multiple tiles into a plurality of sub-tiles; 
 assigning respective sub-sets of the network access points to respective buckets, wherein each of the respective buckets corresponds to one or more sub-tiles of a respective one of the multiple tiles; 
 decimating at least a portion of the network access point information assigned to the respective buckets, wherein decimating the at least a portion of the network access point information comprises:
 for each bucket:
 ranking the network access points assigned to that bucket, and 
 eliminating network access point information for some network access points assigned to that bucket, based at least in part on the ranking, to generate reduced network access point information for that bucket; and 
 
 
 quantizing the reduced network access point information for each bucket, wherein quantizing the reduced network access point information comprises:
 designating a common location for a sub-tile corresponding to a respective bucket; 
 reassigning multiple network access points residing within different locations of the sub-tile to the common location; and 
 further reducing the reduced network access point information for the respective bucket by including the common location for the multiple network access points instead of different location information for the multiple network access points. 
 
 
     
     
       2. The method of  claim 1 , wherein the method comprises, subsequent to decimating at least some access point information from the respective buckets and quantitating access point information of the respective buckets, evaluating the access point information of the respective buckets to determine a location of an access point having a specific identifier. 
     
     
       3. The method of  claim 1 , wherein
 said reassigning comprises reassigning all access points that corresponds with the sub-tile to the common location. 
 
     
     
       4. The method of  claim 1 , wherein network access points that are accessed by client devices more frequently are ranked higher than network access points that are accessed by client devices less frequently. 
     
     
       5. The method of  claim 1 , wherein the method comprises generating multiple files each associated with different tiles of said multiple tiles, wherein each file comprises an index for locating location information for specific network access points within the file. 
     
     
       6. The method of  claim 1 , wherein one or more of the network access points are Wi-Fi access points. 
     
     
       7. A mobile device, comprising:
 a memory; and 
 one or more processors coupled to the memory, wherein the memory comprises program instructions executable by the one or more processors to implement a location component configured to:
 detect a plurality of network access points including at least a first network access point in a first geographic location and a second network access point in a second geographic location; 
 generate a request for one or more tiles including access point information specifying geographic locations of the detected network access points; 
 receive information specifying the one or more tiles, wherein access point information for the one or more tiles has been reduced via decimation and further reduced via quantization, wherein the quantized access point information for the one or more tiles includes a common location for multiple network access points instead of different location information for the multiple network access points; and 
 utilize the first detected network access point or the second detected network access point and the access point information of the one or more tiles to determine a geographic location of the mobile device 
 wherein the location component determines a same geographic location of the mobile device when either the first detected network access point or the second detected network access point is utilized to determine the geographic location of the mobile device, wherein the first network access point and the second network access point are physically located in different geographic locations. 
 
 
     
     
       8. The mobile device of  claim 7 , wherein the information specifying the one or more tiles includes one or more tile files, wherein the location component is configured to generate a database of tiles within the memory based on the files. 
     
     
       9. The mobile device of  claim 8 , wherein the location component is configured to locate within the generated database an entry for the first or second detected network access point. 
     
     
       10. The mobile device of  claim 7 , wherein the location component is configured to generate the request in response to determining that a tile containing location information for the first or second detected network access point does not already reside within said memory. 
     
     
       11. A system, comprising:
 one or more memories; and 
 one or more processors coupled to the one or more memories, wherein the one or more memories comprise program instructions executable by the one or more processors to implement a tile generator configured to reduce information describing a set of network access points and respective locations to generate a reduced information set, wherein the access points are located in a region, wherein to perform the reduction the tile generator is configured to:
 parse the region into multiple tiles and for at least one of the multiple tiles into a plurality of sub-tiles; 
 assign respective sub-sets of the network access points to respective buckets, wherein each of the respective buckets corresponds to one or more sub-tiles of one of the multiple tiles; and 
 decimate at least a portion of the network access point information assigned to the respective buckets, wherein to decimate the at least a portion of the network access point information the tile generator is configured to:
 for each bucket:
 based on a ranking of the network access points in that bucket, eliminate network access point information for some network access points assigned to that bucket to generate the reduced network access point information for that bucket; and 
 store the reduced network access point information for that bucket; and 
 
 
 quantize the reduced network access point information for the respective buckets, wherein to quantize the reduced network access point information the tile generator is configured to:
 designate a common location for a sub-tile corresponding to a respective bucket; 
 reassign multiple network access points residing within different locations of the sub-tile to the common location; and 
 further reduce the reduced network access point information for the respective bucket by including the common location for the multiple network access points instead of different location information for the multiple network access points. 
 
 
 
     
     
       12. The system of  claim 11 , wherein the tile generator is configured to generate a file for each tile, wherein each file comprises an index for expedited searching of multiple location entries for network access points. 
     
     
       13. The system of  claim 11 , wherein network access points that are accessed by client devices more frequently are ranked higher than network access points that are accessed by client devices less frequently. 
     
     
       14. The system of  claim 13 , wherein the tile generator is configured to generate said ranking based on historical access point location information received from multiple client devices. 
     
     
       15. A method, comprising:
 detecting, by a mobile device, an identifier of a first network access point in a first geographic location and an identifier of a second network access point in a second geographic location; 
 generating a request for one or more tiles including information specifying the identifier of the first network access point and a corresponding geographic location and the identifier of the second network access point and a corresponding geographic location; 
 receiving information specifying the one or more tiles, wherein access point information for the one or more tiles has been reduced via decimation and further reduced via quantization, wherein the quantized access point information for the one or more tiles includes a common location for multiple network access points instead of different location information for the multiple network access points; and 
 utilizing the first detected network access point identifier or the second detected network access point identifier and the access point information of the one or more tiles to determine a geographic location of the mobile device, 
 wherein a same geographic location of the mobile device is determined when either the first detected network access point or the second detected network access point is utilized to determine the geographic location of the mobile device, wherein the first network access point and the second network access point are physically located in different geographic locations. 
 
     
     
       16. The method of  claim 15 , wherein the method comprises storing the one or more tiles in a local cache. 
     
     
       17. The method of  claim 15 , wherein the method comprises:
 detecting an identifier of an additional network access point; and 
 in response to determining that an entry for the additional network access point is not in the cache, generating a request to obtain a tile comprising location information for the additional network access point. 
 
     
     
       18. The method of  claim 15 , wherein the method comprises:
 detecting an identifier of an additional network access point; and 
 in response to determining that the cache contains a location entry for the additional network access point, determine the location of the additional network access point based on that location entry. 
 
     
     
       19. The method of  claim 15 , wherein the information specifying the one or more tiles includes an index into a list of location entries for multiple access points, wherein the method further comprises evaluating the index to locate a sub-portion of the list that contains an entry for the first network access point. 
     
     
       20. A non-transitory computer-readable storage medium, storing program instructions computer-executable on a computer to implement a tile generator configured to generate a reduced information set, wherein to perform the reduction the tile generator is configured to:
 receive network access point information for a plurality of network access points located in a region, wherein the network access point information comprises location information for each network access point of the plurality of network access points; 
 parse the region into multiple tiles and for at least one of the multiple tiles into a plurality of sub-tiles; 
 assign respective sub-sets of the network access points to respective buckets, wherein each of the respective buckets corresponds to one or more sub-tiles of one of the multiple tiles; 
 decimate at least a portion of the network access point information assigned to the respective buckets, wherein to decimate the at least a portion of the network access point information the tile generator is configured to:
 for each bucket:
 based on a ranking of the network access points assigned to that bucket, eliminate network access point information for some network access points assigned to that bucket to generate the reduced network access point information for that bucket; and 
 
 
 quantize the reduced network access point information for the respective buckets, wherein to quantize the reduced network access point information the tile generator is configured to:
 for each bucket:
 designate a common location for a sub-tile corresponding to that bucket; 
 reassign multiple network access points residing within different locations of the sub-tile to the common location; and 
 further reduce the reduced network access point information for that bucket by including the common location for the multiple network access points instead of different location information for the multiple network access points in the further reduced network access point information for that bucket. 
 
 
 
     
     
       21. The non-transitory medium of  claim 20 , wherein the tile generator is configured to generate a file for each tile, wherein each file comprises an index for expedited searching of multiple location entries for network access points. 
     
     
       22. The non-transitory medium of  claim 20 , wherein network access points that are accessed by client devices more frequently are ranked higher than network access points that are accessed by client devices less frequently. 
     
     
       23. The non-transitory medium of  claim 22 , wherein the tile generator is configured to generate said ranking based on historical access point location information received from multiple client devices.

Description:
BACKGROUND 
     This application claims benefit of priority to U.S. Provisional Application Ser. No. 61/657,545, entitled “System And Method For Tile-Based Reduction Of Access Point Location Information,” filed Jun. 8, 2012. 
    
    
     TECHNICAL FIELD 
     This disclosure relates generally to reducing a data set, and, more specifically, to reducing a data set that is used for determining the location of a multifunction device or a user of the multifunction device. 
     DESCRIPTION OF THE RELATED ART 
     The capability to determine a user&#39;s location can be found in a number of electronic devices including handheld Global Positioning System (GPS) Devices, as well as mobile phones that have GPS functionality. One common use for such devices includes determining a user&#39;s position for use within an application, such as a mapping or weather application. For instance, within a mapping application, a GPS position may be used to create a graphical indication of the user on a map. This graphical indication may also indicate the user&#39;s proximity to various points-of-interest, such as restaurants, public transit stations, hospitals, fuel stations, convenience stores or other commercial and non-commercial points of interest. In another example, a weather application may use a user&#39;s position to determine which weather forecast should be provided to the user. 
     SUMMARY OF EMBODIMENTS 
     Various embodiments of a system and method for tile-based reduction of access point location information are described. Embodiments may utilize a positioning technique that leverages known locations of network access points to identify the location of a positioning device, even in cases where the positioning device does not include other positioning functionality (e.g., GPS). Embodiments described herein may utilize quantization and decimation techniques to reduce the data footprint of access point location data and also make the data set more nimble to work with (e.g., by providing indexed based searching of the reduced data set). 
     For instance, embodiments may be configured to, based on an aggregate list of access points and associated locations (e.g., latitude and longitude coordinates), generate searchable tiles containing multiple access point identifiers associated with quantized locations which may be shared with other access point identifiers. For a given area referred to as a tile, embodiments may parse the tile into buckets and eliminate at least some access points from the data set based on a bucket-by-bucket analysis. For instance, for each bucket, the data set of access points may be decimated by ranking the access points in that bucket and removing poorly ranked access points from the data set. To quantize the data set, the tile may also be parsed into sub-tiles. Each sub-tile may be designated a geographic location, and multiple (e.g., all) access points within that sub-tile may be assigned that same location. 
     Once the aggregated list of access points and associated locations have been decimated and quantized, the resultant data set may include fewer overall access points for a given region (e.g., the data set may now be focused on the most popular or visible access points for that region), and many of these access points may share the same location due to quantization. These characteristics along with the principles of packing and compression may enable more useable access point location information to be stored in a given memory footprint (on both client side and server side). 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a block diagram including a collection service for collecting access point location information in accordance with some embodiments. 
         FIG. 2  illustrates a block diagram including a tile generator for creating tiles of access point location information in accordance with some embodiments. 
         FIG. 3  illustrates a block of a tile service configured to provide tile files to multifunction devices in accordance with some embodiments. 
         FIG. 4  illustrates an example tile for decimating a data set in accordance with some embodiments. 
         FIG. 5  illustrates a flowchart of example method decimating a data set in accordance with some embodiments. 
         FIG. 6  illustrates an example tile for quantizing a data set in accordance with some embodiments. 
         FIG. 7  illustrates a flowchart of example method quantizing a data set in accordance with some embodiments. 
         FIG. 8  illustrates an example of the structure of a tile file in accordance with some embodiments. 
         FIG. 9  illustrates a block diagram of a location component configured to use tiles for determining a location in accordance with some embodiments. 
         FIGS. 10A-B  illustrate an example multifunction device in accordance with some embodiments. 
         FIG. 11  illustrate an example multifunction device in accordance with some embodiments. 
         FIG. 12  illustrates an example computer system configured to implement aspects of the system and method for tile-based reduction of access point location information. 
         FIG. 13  illustrates example host systems configured to implement a collection service, tile generator and tile service in accordance with some embodiments. 
     
    
    
     This specification includes references to “one embodiment” or “an embodiment.” The appearances of the phrases “in one embodiment” or “in an embodiment” do not necessarily refer to the same embodiment. Particular features, structures, or characteristics may be combined in any suitable manner consistent with this disclosure. 
     “Comprising.” This term is open-ended. As used in the appended claims, this term does not foreclose additional structure or steps. Consider a claim that recites: “An apparatus comprising one or more processor units . . . . ” Such a claim does not foreclose the apparatus from including additional components (e.g., a network interface unit, graphics circuitry, etc.). 
     “Configured To.” Various units, circuits, or other components may be described or claimed as “configured to” perform a task or tasks. In such contexts, “configured to” is used to connote structure by indicating that the units/circuits/components include structure (e.g., circuitry) that performs those task or tasks during operation. As such, the unit/circuit/component can be said to be configured to perform the task even when the specified unit/circuit/component is not currently operational (e.g., is not on). The units/circuits/components used with the “configured to” language include hardware—for example, circuits, memory storing program instructions executable to implement the operation, etc. Reciting that a unit/circuit/component is “configured to” perform one or more tasks is expressly intended not to invoke 35 U.S.C. § 112, sixth paragraph, for that unit/circuit/component. Additionally, “configured to” can include generic structure (e.g., generic circuitry) that is manipulated by software and/or firmware (e.g., an FPGA or a general-purpose processor executing software) to operate in manner that is capable of performing the task(s) at issue. “Configure to” may also include adapting a manufacturing process (e.g., a semiconductor fabrication facility) to fabricate devices (e.g., integrated circuits) that are adapted to implement or perform one or more tasks. 
     “First,” “Second,” etc. As used herein, these terms are used as labels for nouns that they precede, and do not imply any type of ordering (e.g., spatial, temporal, logical, etc.). For example, a buffer circuit may be described herein as performing write operations for “first” and “second” values. The terms “first” and “second” do not necessarily imply that the first value must be written before the second value. 
     “Based On.” As used herein, this term is used to describe one or more factors that affect a determination. This term does not foreclose additional factors that may affect a determination. That is, a determination may be solely based on those factors or based, at least in part, on those factors. Consider the phrase “determine A based on B.” While in this case, B is a factor that affects the determination of A, such a phrase does not foreclose the determination of A from also being based on C. In other instances, A may be determined based solely on B. 
     DETAILED DESCRIPTION 
     Introduction 
     Various embodiments of a system and method for tile-based reduction of access point location information are described. Embodiments may utilize a positioning technique that leverages known locations of network access points (e.g., Wi-Fi and/or other types of data network access points) to identify the location of a positioning device, even in cases where the positioning device does not include other positioning functionality (e.g., GPS). Note that embodiments are not limited to Wi-Fi access points and may include access points adhering to other wireless communication standards. Given an access point identifier, embodiments may return a location associated with that access point identifier. Some positioning techniques based on known locations of access points may employ a one-to-one mapping between access point identifiers (e.g., MAC addresses) and location coordinates (e.g., latitude and longitude). Various embodiments described herein may utilize quantization and decimation techniques to reduce the data footprint of access point location data and also make the data set more nimble to work with (e.g., by providing indexed based searching of the quantized and decimated data set). 
     For instance, embodiments may be configured to, based on an aggregate list of access points and associated locations (e.g., latitude and longitude coordinates), generate searchable tiles containing multiple access point identifiers associated with quantized locations which may be shared with other access point identifiers. For a given area (e.g., a 0.05° latitude by 0.05° longitude area of the Earth) referred to as a tile, embodiments may parse the tile into n “buckets.” Each bucket may correspond to a specific sub-area of the tile; embodiments may determine which access points map to that bucket based on the aforesaid aggregate list of access points and associated locations. For each bucket, embodiments may decimate the access points within that bucket using various criteria. In one non-limiting example, embodiments may keep the top 50% of access points in terms of a determined popularity score or ranking and discard the lower 50% (other techniques are described in more detail below). This process may be repeated for each bucket of a given tile. In various embodiments, the access points that remain in each tile&#39;s data set after decimation may be quantized. For instance, for a given tile, the tile may be parsed into m sub-tiles. Generally, this parsing process may result in more sub-tiles than the corresponding number of buckets used for decimation as described above (that is, generally m&gt;n); as such, the area corresponding of each sub-tile will generally be smaller than the area corresponding to a given bucket. (Although in some cases the sub-tiles used for quantization may be the same as the buckets used for decimation.) To quantize all of the access points remaining after decimation, embodiments may, for each sub-tile, designate a location to that sub-tile and assign that location to multiple (e.g., all) access points residing within that sub-tile. In this way, in some embodiments, all access points within a given sub-tile may be assigned the same location (e.g., coordinates) even though such access points may not share the exact same location in reality. 
     Once the aggregated list of access points and associated locations have been decimated and quantized, the resultant data set may include fewer overall access points for a given region (e.g., the data set may now be focused on the most popular or visible access points for that region) and of these access points many may now share the same location due to quantization. These characteristics along with the principles of packing and compression may enable more useable access point location information to be stored in a given memory footprint, which may conserve memory space on client devices (e.g., smartphones) and server-side (e.g., on one or more servers implementing a service providing access point location data). By enabling more useable access point location information to be stored in a given memory footprint, embodiments may improve availability (e.g., instances in which a fix is acquired, even when no cellular data access is available on a client device) and decrease cellular data use (e.g., a client device will need to request less information from the server-side for a given geographical area). In general, the reduced data set described herein may cover a larger geographical area with a smaller memory footprint relative to the unreduced data set (e.g., a list of access points and respective locations). 
     By utilizing a data set reduced according to the decimation and quantization techniques described herein, client devices (such as the multifunction devices described herein) may pre-cache larger geographical areas in order to support off network access point (e.g., Wi-Fi) locations. This caching may also reduce the amount of server queries while the client device determines access point locations on the move. Having a larger geographical area cached may also reduce the time to first fix (e.g., the time a first location is determined on the device), which represents a convenience for the user. 
     Various embodiments described herein may include a multifunction device operated by a user. For example, a multifunction device may be a smartphone utilized by an individual to make phone calls, send text messages, browse the internet, etc. As use of multifunction device by an individual generally implies the individual is proximate to the multifunction device (e.g., the user may be holding the device in his or her hand), references herein to the location of the device and the location of the user may be considered to be synonymous. However, it should be understood that in some cases the actual position of the multifunction device and the user of that device may differ by some distance. For instance, the user may place his or her multifunction device on a table of an outdoor café while sitting in a nearby chair. In this case, the position of the device and the position of the user may differ by some small amount. In another example, a multifunction device may be mounted on a car dashboard (e.g., for use as a navigation device) while the user of the device sits nearby (e.g., in the driver seat of the car). In this case as well, the position of the device and the position of the user may differ by some small amount. Despite these small differences in position, generally the position of the multifunction device and the position of the multifunction device user may be considered to coincide. 
     Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present embodiments. However, it will be apparent to one of ordinary skill in the art that the present embodiments may be practiced without these specific details. In other instances, well-known methods, procedures, components, circuits, and networks have not been described in detail so as not to unnecessarily obscure aspects of various embodiments. 
     Tile-Based Reduction of Access Point Location Information 
     Various embodiments of the system and method for tile-based reduction of access point location information may perform data set reduction on access point location information reported by client devices, such as any of the portable multifunction devices described above.  FIG. 1  illustrates one example of the collection of access point location information. In the illustrated embodiment, one or more multifunction devices  100  may report access point location information  102  to a collection service  110 . In various embodiments, each client device may generate its own access point location information  102 . For instance, when a multifunction device detects an access point, such as access point  1310  described below, the multifunction device may record the location at which the access point was detected. In various embodiments, the multifunction device may record coordinates (e.g., latitude and longitude values) specifying the device location when the access point was detected, such as coordinates determined with GPS module  1035  or orientations sensors  1068  described below with respect to the example multifunction device. The multifunction device may also record an identifier for the detected access point, such as a media access control (MAC) address. The multifunction device may also record altitude, such as a determined or estimated altitude as described above with respect to orientation sensors  1068 . The multifunction device may also record a measure of signal strength for the detected access point (e.g., generally the stronger the signal, the closer the multifunction device is to the access point). Any of the aforesaid information may be included as part of access point location information  102  and sent to collection service  110 . Collection service may aggregate access point location information  102  into a data store of access point location information  112 . In various embodiments, access point location information  112  may, for each access point of multiple access points across one or more regions, specify a corresponding location for that access point. In one non-limiting example, the records of access point location information may associate access point identifiers (e.g., MAC addresses) and specific locations (e.g., coordinates). 
     In various embodiments, collection service  452  may utilize crowd-sourcing techniques to curate access point location information for many different access points in a database of access point location information. For instance, some multifunction devices may have capabilities (e.g., GPS positioning) that other multifunction devices do not necessarily have. In one non-limiting example, a smartphone might contain GPS positioning functionality while a tablet device may not include GPS positioning functionality. In various embodiments, the group of multifunction devices  100  may be devices capable of independently verifying device location (e.g., via a GPS module). As described in more detail below, the access point location information collected from these devices may be used to assist less capable devices (e.g., devices without GPS positioning functionality) with determining position. For instance, embodiments may enable such devices to determine position based on one or more access point tiles as described in more detail below. 
     In some embodiments, access point location information  112  may be stored in structured or unstructured formats, such as a file of comma separated values (CSV) specifying different access points, respective locations (e.g., latitude and longitude coordinates), and/or other information. In some cases, access point location information  112  may be referred to herein as unreduced access point location information. 
       FIG. 2  illustrates a tile generator configured to create tiles (e.g., the files  210 ) for multiple regions based on the access point location information  112 . The techniques utilized by the tile generator are described in more detail below. Generally, tile generator  200  may be configured to utilize the decimation and quantization techniques described in more detail below in order to generate tile files  210  representing various regions. These files may be requested by client devices and used to identify the location of the device. 
       FIG. 3  illustrates an example of a multifunction device  300  sending a service request  310  to a tile service  320 . The service request  310  may specify one or more identifiers of access points detected by multifunction device  300  including but not limited to MAC addresses of access points. In one non-limiting example, multifunction device  300  may detect one or more nearby access points and send respective identifiers of the access point(s) in request  310 . Tile service  320  may be configured to return one or more tile files indicating access points in the geographic region in which the specified access point resides and the surrounding areas, as illustrated by tile files  312 . Multifunction device  300  may use the tile files to determine or infer the current location of the device, as described in more detail below. 
       FIG. 4  illustrates a graphical representation of a tile  400  used to decimate the access point location information for a region. This region may be defined by a tile width  410  and a tile height  420 . In the illustrated embodiment, tile width  410  is illustrated as being 0.05° longitude; tile height  420  is illustrated as being 0.05° latitude. These values are merely non-limiting examples. In other cases, other tiles sizes may be utilized. In the illustrated embodiment, tile generator  200  may generate tile  400  by parsing a region (e.g., a geographical region, city, state, country, and/or world, etc.) into multiple tiles. Each tile may also be parsed or divided into multiple sub-areas referred to herein as “buckets”. In the illustrated embodiment, each bucket measures approximately 50 meters by 50 meters. These values are merely non-limiting examples. For each region having a corresponding tile, tile generator  200  may utilize a tile similar to tile  400  in order to perform decimation, which is described in more detail below with respect to  FIG. 5 . Generally, for a given tile, decimation may be performed as a bucket-by-bucket analysis that eliminates one or more access points from each bucket. In various embodiments, decimation may include exception cases in which access points are not removed from a bucket, such as when a bucket contains only one access point or a few access points. 
     In various embodiments, tile generator  200  may generate a stored representation of each tile (e.g., the  400 ). Furthermore, for each tile, tile generator  200  may also indicate within that stored representation which access points are located within each bucket of the tile. Generally, buckets may contain none, one, or multiple access points. In one non-limiting example, buckets representing locations that include urban areas may generally include more access points than buckets representing locations within rural areas. For at least some buckets of a tile, the decimation process described below may remove one or more access points from the data set. Various techniques for determining which access points should be removed from consideration are described in more detail below with respect to  FIG. 5 . In one non-limiting example, access points that are less popular or less visible to client devices in the field may be removed from the data set. 
       FIG. 5  illustrates a flowchart of a decimation process. In various embodiments, tile generator  200  may be configured to perform decimation according to a method that is the same as or similar to the illustrated method. In various embodiments, the illustrated method may be performed by one or more computers, such as the computer illustrated in  FIG. 12  below. In various embodiments, the illustrated method may be performed for a specific tile (e.g., the  400 ) and repeated for multiple other tiles. 
     As illustrated at block  500 , the method may include selecting an un-decimated bucket of access points from the data set (e.g., a bucket of access points that has not yet been processed according to the illustrated method). In some cases, multiple buckets may be selected and processed in parallel. As illustrated at block  502 , the method may include ranking the access points of the selected bucket based on one or more ranking criteria. In various embodiments, access points of a bucket may be ranked in order of descending visibility, which may be measured in different ways in different embodiments. In one example, the access points that are statistically “seen” the most may be ranked the highest. For instance, access points that have been reported the most by client devices (see e.g.,  FIG. 1 ) may be considered to be more visible than less frequently reported access points. In other cases, access points that have strong signal strength may be ranked higher than access points with weaker signal strength. In other cases, some combination of these ranking techniques may be utilized. Generally, it may be preferred to remove low visibility access points before higher visibility access points. For instance, when using the reduced data set to determine a device&#39;s location, the most visible access points may be the most likely to be detected by a client device in the field. 
     As illustrated by blocks  504  to  512 , the method may utilize multiple tiers of thresholds to “thin” or decimate the data set. In block  504 , the method may include determining whether the quantity of access point in the bucket exceeds a first threshold. In the illustrated embodiment, this first threshold is specified as 15 access points but need not be 15 in all cases; the illustrated thresholds are merely examples and different thresholds (and/or different quantities of thresholds) may be utilized in various embodiments. As illustrated by the positive output of block  504 , the method may include selecting the top W ranked access points (block  506 ). In the illustrated embodiment, the value of W is specified as 10 access points but need not be 10 in all cases; the illustrated value for W is merely an example. As illustrated at block  518 , access points that were not selected at block  506  are removed from the data set, which leaves the top W ranked access points remaining in the data set for the current bucket. As illustrated by the negative output of block  504 , the method may proceed to block  508  if the quantity of access points in the bucket does not meet or exceed the first threshold. 
     In block  508 , the method may include determining whether the quantity of access point in the bucket exceeds a second threshold. In the illustrated embodiment, this second threshold is specified as 10 access points but need not be 10 in all cases; the illustrated thresholds are merely examples and different thresholds may be utilized in various embodiments. As illustrated by the positive output of block  508 , the method may include selecting the top X ranked access points (block  510 ). In the illustrated embodiment, the value of X is specified as seven access points but need not be seven in all cases; the illustrated value for X is merely an example. As illustrated at block  518 , access points that were not selected at block  510  are removed from the data set, which leaves the top X ranked access points remaining in the data set for the current bucket. As illustrated by the negative output of block  508 , the method may proceed to block  512  if the quantity of access points in the bucket does not meet or exceed the second threshold. 
     In block  512 , the method may include determining whether the quantity of access point in the bucket exceeds a third threshold. In the illustrated embodiment, this third threshold is specified as five access points but need not be five in all cases; the illustrated thresholds are merely examples and different thresholds may be utilized in various embodiments. As illustrated by the positive output of block  512 , the method may include selecting the top Y ranked access points (block  514 ). In the illustrated embodiment, the value of Y is specified as five access points but need not be five in all cases; the illustrated value for Y is merely an example. As illustrated at block  518 , access points that were not selected at block  510  are removed from the data set, which leaves the top Y ranked access points remaining in the data set for the current bucket. As illustrated by the negative output of block  512 , the method may proceed to block  516  if the quantity of access points in the bucket does not meet or exceed the third threshold. 
     At block  516 , the method may select the top Z ranked access. In the illustrated embodiment, the value of Z is specified as five access points but need not be five in all cases; the illustrated value for Z is merely an example. Generally, some or all of the access points not eliminated by the thresholds of block  504 ,  508  and  512  may be selected at block  518 . As illustrated at block  518 , access points that were not selected at block  516  are removed from the data set, which leaves the top Z ranked access points remaining in the data set for the current bucket. 
     At block  520 , the method may include determining whether any more unprocessed buckets remain for the access point tile. If it is determine that additional buckets remain unprocessed, the method may proceed to block  500  at which point the method is performed for another bucket. If it is determine that no additional buckets remain, the method may end. 
     After tile generator  200  performs decimation (e.g., in accordance with the method of  FIG. 5 ), the access point location information for a given region may be reduced as less significant access points (e.g., low visibility access points) are culled from the data set. As described in more detail below, the reduced data footprint of the reduced access point location information may enable access point location information covering a larger geographical region to be stored for a given cache size on client devices. Generally caching a large geographical area of access point location information may enable client devices that do not have dedicated positioning hardware (e.g., a GPS component) and/or cellular data connectivity to determine device location more consistently. 
     While decimation may cull less significant access points from the data set, embodiments may also utilize quantization and indices to further reduce the data size of the decimated data set. An example of the quantization process utilized by tile generator  200  is described in more detail with respect to  FIGS. 6 and 7 .  FIG. 6  illustrates a tile  600 , which may be the same as or similar to tile  400  described above. This region may be defined by a tile width  610  and a tile height  620 . In the illustrated embodiment, tile width  610  is illustrated as being 0.05° longitude; tile height  620  is illustrated as being 0.05° latitude. These values are merely non-limiting examples. In other cases, other tiles sizes may be utilized. In the illustrated embodiment, tile generator  200  may generate tile  600  by parsing a region (e.g., a geographical region, city, state, country, and/or world, etc.) into multiple tiles. Generally the tiles used for decimation and the tiles used for quantization will be of the same size and cover the same area. For quantization, each tile may also be parsed or divided into multiple sub-areas referred to herein as “sub-tiles”. In the illustrated embodiment, each sub-tile measures approximately 21 meters by 21 meters. These values are merely non-limiting examples. In the illustrated embodiment, the sub-tile size chosen is based on an indexed addressing scheme. For instance, one byte may address up to 256 different positions. By using two bytes, embodiments may reference up to 65,536 unique sub-tiles within a tile (e.g., 256 rows and 256 columns). In the illustrated embodiment, the sub-tiles may be approximately 21 meters square as 0.05° longitude or latitude divided by 256 equates to 0.0015°, which is approximately 21 meters on Earth. For each region having a corresponding tile, tile generator  200  may utilize a tile similar to tile  600  in order to perform quantization, which is described in more detail below with respect to  FIG. 7 . Generally, for a given tile, quantization may be performed as a sub-tile by sub-tile analysis that designates a geographical location to the sub-tile and assigns that geographical location to multiple (e.g., all) access points within the sub-tile. This may reduce the accuracy of the access point locations by an acceptable amount while enabling an indexing scheme that reduces the memory footprint of the access point location information. 
       FIG. 7  illustrates a flowchart of a quantization process. In various embodiments, tile generator  200  may be configured to perform decimation according to a method that is the same as or similar to the illustrated method. In various embodiments, the illustrated method may be performed by one or more computers, such as the computer illustrated in  FIG. 12  below. In various embodiments, the illustrated method may be performed for a specific tile (e.g., the  600 ) and repeated for multiple other tiles. 
     As illustrated at block  700 , the method may include selecting an un-quantized sub-tile of access points from the data set (e.g., a sub-tile of access points that has not yet been processed according to the illustrated method). In some cases, multiple sub-tiles may be selected and processed in parallel. As illustrated at block  702 , the method may include designating a location to the sub-tile. The specific location may be configurable, but in various embodiments will be consistent across sub-tiles. For instance, if a tile is referenced by the geographic location of that tile&#39;s northwest corner, each sub-tile&#39;s location may be designated as the northwest corner of that sub-tile. 
     As illustrated at block  704 , the method may include assigning the designated location of the sub-tile to all access points residing in the geographic region represented by that sub-tile. In this way, multiple access points having different locations within a sub-tile may be reassigned to a common location. This may reduce the accuracy of the access point locations by an acceptable amount while enabling an indexing scheme that reduces the memory footprint of the access point location information. The indexing scheme is described in more detail below with respect to the file structure of  FIG. 8 . As illustrated, the method may include determining whether there are more sub-tiles for the tile being evaluated. If there are, the method may return to block  700 . If there are not more sub-tiles to be evaluated, the method may end. 
       FIG. 8  illustrates the structure of a tile file according to some embodiments. In various embodiments, the illustrated tile file may represent one or more of tiles files  210  described above. As illustrated, the tile file may include a tile header  802 , which may include but is not limited to header information, an x-y coordinate of the tile, a geographic location of the tile (e.g., latitude and longitude coordinates specifying a geographic location of a corner of the tile), and/or altitude information. The file may also include a MAC address index  804  into a table of sorted access points  806 . In various embodiments, each access points may be referenced by its MAC address and x-y coordinates that are based on the sub-tile grid created during quantization (as described above). The associated geographic location may be inferred from these x-y coordinates and the known location of the overall tile (e.g., as specified by the tile header). In various embodiments, use of a MAC index into the table of access points may reduce the overall time to locate the entry for a specific access point. For instance, instead of performing a search of the entire access point table, the index may scope the search to a much smaller section of the table. In one non-limiting example, use of an index may reduce the search space from 100% of the access point table down to approximately 5% of the access point table. Generally, to determine a location for the device based on an observed access point, the location component (described below) may read the tile index and search (e.g., binary search) the index to identify the relevant portion of the access point table. The tile manager may then read the relevant section from the access point table and search (e.g., binary search) that section for the observed access point. Tiles that are not already stored locally may be added to the acquisition list (described below) and downloaded when connectivity becomes available. 
       FIG. 9  illustrates a location component of a multifunction device. In the illustrated embodiment, other components that may be included as part of a multifunction device are described below with respect to  FIGS. 10-11  but are absent from  FIG. 9  for clarity of illustration. In the illustrated embodiment, a location component  910  of multifunction device  900  may be configured to determine a past or present location of the multifunction device based on tile files  952   a - n  of file system  950 . In various embodiments, these files may be similar to or the same as tile files  210  described above and may have a structure that is similar to or the same as tile file  800  described above. Tile manager  920  may be configured to manage the acquisition of tile files and request needed tiles from a tile service, such as illustrated in  FIG. 3 . In the illustrated embodiment, tile manager  920  may maintain caches for the most recently used known and unknown access points, which are illustrated as caches  940  and  942 . In various embodiments, the location component may collect visible access points periodically or aperiodically (e.g., throughout the day). For instance, such collection may be performed through opportunistic Wi-Fi scans on the multifunction device; those access points may be queried when connectivity is available. Furthermore, when those access points become known, the multifunction device may download tiles for those access points as well as surrounding tiles. In various embodiments, the MAC addresses of access points corresponding to desired tiles may be added to acquisition list  970  and opportunistically downloaded when connectivity is available. The corresponding tiles (e.g., tiles  952   a - n ) may be received and tile manager  920  may generate a tile database  980  that may be used to identify device location based on access point identifiers (e.g., a MAC address) at runtime. This location may be used in a variety of location-aware applications on the multifunction devices including but not limited to mapping applications, navigation application, weather applications, and/or social networking applications. 
     In various embodiments, one or more security measures may be implemented by the location component. For instance, a clean up timer  960  may be utilized to trigger the removal of tiles not used for a certain time period (e.g., 7 days). In some embodiments, the tile files may be encrypted on file system  950 . Furthermore, when location services are switched off on the multifunction device, the tile manager may delete all cached tiles. In some embodiments, file names of tile files may be scrambled (e.g., through use of random filenames). Generally, a tile file may contain all the information needed in order to use the tile without relying on the filename. 
     Example Multifunction Device 
     Embodiments of electronic devices, user interfaces for such devices, and associated processes for using such devices are described. In some embodiments, the device is a portable communications device, such as a mobile telephone, that also contains other functions, such as PDA and/or music player functions. Exemplary embodiments of portable multifunction devices include, without limitation, the iPhone®, iPod Touch®, and iPad® devices from Apple Inc. of Cupertino, Calif. Other portable electronic devices, such as laptops or tablet computers with touch-sensitive surfaces (e.g., touch screen displays and/or touch pads), may also be used. It should also be understood that, in some embodiments, the device is not a portable communications device, but is a desktop computer with a touch-sensitive surface (e.g., a touch screen display and/or a touch pad). In some embodiments, the device is a gaming computer with orientation sensors (e.g., orientation sensors in a gaming controller). 
     In the discussion that follows, an electronic device that includes a display and a touch-sensitive surface is described. It should be understood, however, that the electronic device may include one or more other physical user-interface devices, such as a physical keyboard, a mouse and/or a joystick. 
     The device typically supports a variety of applications, such as one or more of the following: a drawing application, a presentation application, a word processing application, a website creation application, a disk authoring application, a spreadsheet application, a gaming application, a telephone application, a video conferencing application, an e-mail application, an instant messaging application, a workout support application, a photo management application, a digital camera application, a digital video camera application, a web browsing application, a digital music player application, and/or a digital video player application. 
     The various applications that may be executed on the device may use at least one common physical user-interface device, such as the touch-sensitive surface. One or more functions of the touch-sensitive surface as well as corresponding information displayed on the device may be adjusted and/or varied from one application to the next and/or within a respective application. In this way, a common physical architecture (such as the touch-sensitive surface) of the device may support the variety of applications with user interfaces that are intuitive and transparent to the user. 
     Attention is now directed toward embodiments of portable devices with touch-sensitive displays.  FIG. 10A  is a block diagram illustrating portable multifunction device  1000  with touch-sensitive displays  1012  in accordance with some embodiments. Touch-sensitive display  1012  is sometimes called a “touch screen” for convenience, and may also be known as or called a touch-sensitive display system. Device  1000  may include memory  1002  (which may include one or more computer readable storage mediums), memory controller  1022 , one or more processing units (CPU&#39;s)  1020 , peripherals interface  1018 , RF circuitry  1008 , audio circuitry  1010 , speaker  1011 , microphone  1013 , input/output (I/O) subsystem  1006 , other input or control devices  1016 , and external port  1024 . Device  1000  may include one or more optical sensors  1064 . These components may communicate over one or more communication buses or signal lines  1003 . 
     It should be appreciated that device  1000  is only one example of a portable multifunction device, and that device  1000  may have more or fewer components than shown, may combine two or more components, or may have a different configuration or arrangement of the components. The various components shown in  FIG. 10A  may be implemented in hardware, software, or a combination of both hardware and software, including one or more signal processing and/or application specific integrated circuits. 
     Memory  1002  may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state memory devices. Access to memory  1002  by other components of device  1000 , such as CPU  1020  and the peripherals interface  1018 , may be controlled by memory controller  1022 . 
     Peripherals interface  1018  can be used to couple input and output peripherals of the device to CPU  1020  and memory  1002 . The one or more processors  1020  run or execute various software programs and/or sets of instructions stored in memory  1002  to perform various functions for device  1000  and to process data. 
     In some embodiments, peripherals interface  1018 , CPU  1020 , and memory controller  1022  may be implemented on a single chip, such as chip  1004 . In some other embodiments, they may be implemented on separate chips. 
     RF (radio frequency) circuitry  1008  receives and sends RF signals, also called electromagnetic signals. RF circuitry  1008  converts electrical signals to/from electromagnetic signals and communicates with communications networks and other communications devices via the electromagnetic signals. RF circuitry  1008  may include well-known circuitry for performing these functions, including but not limited to an antenna system, an RF transceiver, one or more amplifiers, a tuner, one or more oscillators, a digital signal processor, a CODEC chipset, a subscriber identity module (SIM) card, memory, and so forth. RF circuitry  1008  may communicate with networks, such as the Internet, also referred to as the World Wide Web (WWW), an intranet and/or a wireless network, such as a cellular telephone network, a wireless local area network (LAN) and/or a metropolitan area network (MAN), and other devices by wireless communication. The wireless communication may use any of multiple communications standards, protocols and technologies, including but not limited to Global System for Mobile Communications (GSM), Enhanced Data GSM Environment (EDGE), high-speed downlink packet access (HSDPA), high-speed uplink packet access (HSUPA), wideband code division multiple access (W-CDMA), code division multiple access (CDMA), time division multiple access (TDMA), Bluetooth, Wireless Fidelity (Wi-Fi) (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g and/or IEEE 802.11n), voice over Internet Protocol (VoIP), Wi-MAX, a protocol for e-mail (e.g., Internet message access protocol (IMAP) and/or post office protocol (POP)), instant messaging (e.g., extensible messaging and presence protocol (XMPP), Session Initiation Protocol for Instant Messaging and Presence Leveraging Extensions (SIMPLE), Instant Messaging and Presence Service (IMPS)), and/or Short Message Service (SMS), or any other suitable communication protocol, including communication protocols not yet developed as of the filing date of this document. 
     Audio circuitry  1010 , speaker  1011 , and microphone  1013  provide an audio interface between a user and device  100 . Audio circuitry  1010  receives audio data from peripherals interface  1018 , converts the audio data to an electrical signal, and transmits the electrical signal to speaker  1011 . Speaker  1011  converts the electrical signal to human-audible sound waves. Audio circuitry  1010  also receives electrical signals converted by microphone  1013  from sound waves. Audio circuitry  1010  converts the electrical signal to audio data and transmits the audio data to peripherals interface  1018  for processing. Audio data may be retrieved from and/or transmitted to memory  1002  and/or RF circuitry  1008  by peripherals interface  1018 . In some embodiments, audio circuitry  1010  also includes a headset jack (e.g.,  1112 ,  FIG. 11 ). The headset jack provides an interface between audio circuitry  1010  and removable audio input/output peripherals, such as output-only headphones or a headset with both output (e.g., a headphone for one or both ears) and input (e.g., a microphone). 
     I/O subsystem  1006  couples input/output peripherals on device  1000 , such as touch screen  1012  and other input control devices  1016 , to peripherals interface  1018 . I/O subsystem  1006  may include display controller  1056  and one or more input controllers  1060  for other input or control devices. The one or more input controllers  1060  receive/send electrical signals from/to other input or control devices  116 . The other input control devices  1016  may include physical buttons (e.g., push buttons, rocker buttons, etc.), dials, slider switches, joysticks, click wheels, and so forth. In some alternate embodiments, input controller(s)  1060  may be coupled to any (or none) of the following: a keyboard, infrared port, USB port, and a pointer device such as a mouse. The one or more buttons (e.g.,  1108 ,  FIG. 11 ) may include an up/down button for volume control of speaker  1011  and/or microphone  1013 . The one or more buttons may include a push button (e.g.,  1106 ,  FIG. 11 ). 
     Touch-sensitive display  1012  provides an input interface and an output interface between the device and a user. Display controller  1056  receives and/or sends electrical signals from/to touch screen  1012 . Touch screen  1012  displays visual output to the user. The visual output may include graphics, text, icons, video, and any combination thereof (collectively termed “graphics”). In some embodiments, some or all of the visual output may correspond to user-interface objects. 
     Touch screen  1012  has a touch-sensitive surface, sensor or set of sensors that accepts input from the user based on haptic and/or tactile contact. Touch screen  1012  and display controller  1056  (along with any associated modules and/or sets of instructions in memory  1002 ) detect contact (and any movement or breaking of the contact) on touch screen  1012  and converts the detected contact into interaction with user-interface objects (e.g., one or more soft keys, icons, web pages or images) that are displayed on touch screen  1012 . In an exemplary embodiment, a point of contact between touch screen  1012  and the user corresponds to a finger of the user. 
     Touch screen  1012  may use LCD (liquid crystal display) technology, LPD (light emitting polymer display) technology, or LED (light emitting diode) technology, although other display technologies may be used in other embodiments. Touch screen  1012  and display controller  1056  may detect contact and any movement or breaking thereof using any of multiple touch sensing technologies now known or later developed, including but not limited to capacitive, resistive, infrared, and surface acoustic wave technologies, as well as other proximity sensor arrays or other elements for determining one or more points of contact with touch screen  1012 . In an exemplary embodiment, projected mutual capacitance sensing technology is used, such as that found in the iPhone®, iPod Touch®, and iPad® from Apple Inc. of Cupertino, Calif. 
     Touch screen  1012  may have a video resolution in excess of 100 dpi. In some embodiments, the touch screen has a video resolution of approximately 300 dpi. The user may make contact with touch screen  1012  using any suitable object or appendage, such as a stylus, a finger, and so forth. In some embodiments, the user interface is designed to work primarily with finger-based contacts and gestures, which can be less precise than stylus-based input due to the larger area of contact of a finger on the touch screen. In some embodiments, the device translates the rough finger-based input into a precise pointer/cursor position or command for performing the actions desired by the user. 
     In some embodiments, in addition to the touch screen, device  1000  may include a touchpad (not shown) for activating or deactivating particular functions. In some embodiments, the touchpad is a touch-sensitive area of the device that, unlike the touch screen, does not display visual output. The touchpad may be a touch-sensitive surface that is separate from touch screen  1012  or an extension of the touch-sensitive surface formed by the touch screen. 
     Device  1000  also includes power system  1062  for powering the various components. Power system  1062  may include a power management system, one or more power sources (e.g., battery, alternating current (AC)), a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator (e.g., a light-emitting diode (LED)) and any other components associated with the generation, management and distribution of power in portable devices. 
     Device  1000  may also include one or more optical sensors  1064 .  FIG. 10A  shows an optical sensor coupled to optical sensor controller  1058  in I/O subsystem  1006 . Optical sensor  1064  may include charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) phototransistors. Optical sensor  1064  receives light from the environment, projected through one or more lens, and converts the light to data representing an image. In conjunction with imaging module  1043  (also called a camera module), optical sensor  1064  may capture still images or video. In some embodiments, an optical sensor is located on the back of device  1000 , opposite touch screen display  1012  on the front of the device, so that the touch screen display may be used as a viewfinder for still and/or video image acquisition. In some embodiments, another optical sensor is located on the front of the device so that the user&#39;s image may be obtained for videoconferencing while the user views the other video conference participants on the touch screen display. 
     Device  1000  may also include one or more proximity sensors  1066 .  FIG. 10A  shows proximity sensor  1066  coupled to peripherals interface  1018 . Alternately, proximity sensor  166  may be coupled to input controller  1060  in I/O subsystem  1006 . In some embodiments, the proximity sensor turns off and disables touch screen  1012  when the multifunction device is placed near the user&#39;s ear (e.g., when the user is making a phone call). 
     Device  1000  includes one or more orientation sensors  1068 . In some embodiments, the one or more orientation sensors include one or more accelerometers (e.g., one or more linear accelerometers and/or one or more rotational accelerometers). In some embodiments, the one or more orientation sensors include one or more gyroscopes. In some embodiments, the one or more orientation sensors include one or more magnetometers. In some embodiments, the one or more orientation sensors include one or more altimeters configured to determine or estimate the altitude of the multifunction device. In some embodiments, the one or more orientation sensors include one or more of global positioning system (GPS), Global Navigation Satellite System (GLONASS), and/or other global navigation system receivers. The GPS, GLONASS, and/or other global navigation system receivers may be used for obtaining information concerning the location and orientation (e.g., portrait or landscape) of device  1000 . In some embodiments, the one or more orientation sensors include any combination of orientation/rotation sensors.  FIG. 10A  shows the one or more orientation sensors  1068  coupled to peripherals interface  1018 . Alternately, the one or more orientation sensors  1068  may be coupled to an input controller  1060  in I/O subsystem  1006 . In some embodiments, information is displayed on the touch screen display in a portrait view or a landscape view based on an analysis of data received from the one or more orientation sensors. 
     In some embodiments, the software components stored in memory  1002  include operating system  1026 , communication module (or set of instructions)  1028 , contact/motion module (or set of instructions)  1030 , graphics module (or set of instructions)  1032 , text input module (or set of instructions)  1034 , Global Positioning System (GPS) module (or set of instructions)  1035 , and applications (or sets of instructions)  1036 . Furthermore, in some embodiments memory  1002  stores device/global internal state  1057 , as shown in  FIGS. 10A . Device/global internal state  1057  includes one or more of: active application state, indicating which applications, if any, are currently active; display state, indicating what applications, views or other information occupy various regions of touch screen display  1012 ; sensor state, including information obtained from the device&#39;s various sensors and input control devices  1016 ; and location information concerning the device&#39;s location and/or attitude. 
     Operating system  1026  (e.g., Darwin, RTXC, LINUX, UNIX, OS X, WINDOWS, or an embedded operating system such as VxWorks) includes various software components and/or drivers for controlling and managing general system tasks (e.g., memory management, storage device control, power management, etc.) and facilitates communication between various hardware and software components. 
     Communication module  1028  facilitates communication with other devices over one or more external ports  1024  and also includes various software components for handling data received by RF circuitry  1008  and/or external port  1024 . External port  1024  (e.g., Universal Serial Bus (USB), FIREWIRE, etc.) is adapted for coupling directly to other devices or indirectly over a network (e.g., the Internet, wireless LAN, etc.). In some embodiments, the external port is a multi-pin (e.g., 30-pin) connector that is the same as, or similar to and/or compatible with the 30-pin connector used on iPod (trademark of Apple Inc.) devices. 
     Contact/motion module  1030  may detect contact with touch screen  1012  (in conjunction with display controller  1056 ) and other touch sensitive devices (e.g., a touchpad or physical click wheel). Contact/motion module  1030  includes various software components for performing various operations related to detection of contact, such as determining if contact has occurred (e.g., detecting a finger-down event), determining if there is movement of the contact and tracking the movement across the touch-sensitive surface (e.g., detecting one or more finger-dragging events), and determining if the contact has ceased (e.g., detecting a finger-up event or a break in contact). Contact/motion module  1030  receives contact data from the touch-sensitive surface. Determining movement of the point of contact, which is represented by a series of contact data, may include determining speed (magnitude), velocity (magnitude and direction), and/or an acceleration (a change in magnitude and/or direction) of the point of contact. These operations may be applied to single contacts (e.g., one finger contacts) or to multiple simultaneous contacts (e.g., “multitouch”/multiple finger contacts). In some embodiments, contact/motion module  1030  and display controller  1056  detect contact on a touchpad. 
     Contact/motion module  1030  may detect a gesture input by a user. Different gestures on the touch-sensitive surface have different contact patterns. Thus, a gesture may be detected by detecting a particular contact pattern. For example, detecting a finger tap gesture includes detecting a finger-down event followed by detecting a finger-up (lift off) event at the same position (or substantially the same position) as the finger-down event (e.g., at the position of an icon). As another example, detecting a finger swipe gesture on the touch-sensitive surface includes detecting a finger-down event followed by detecting one or more finger-dragging events, and subsequently followed by detecting a finger-up (lift off) event. 
     Graphics module  1032  includes various known software components for rendering and displaying graphics on touch screen  1012  or other display, including components for changing the intensity of graphics that are displayed. As used herein, the term “graphics” includes any object that can be displayed to a user, including without limitation text, web pages, icons (such as user-interface objects including soft keys), digital images, videos, animations and the like. 
     In some embodiments, graphics module  1032  stores data representing graphics to be used. Each graphic may be assigned a corresponding code. Graphics module  1032  receives, from applications etc., one or more codes specifying graphics to be displayed along with, if necessary, coordinate data and other graphic property data, and then generates screen image data to output to display controller  1056 . 
     Text input module  134 , which may be a component of graphics module  1032 , provides soft keyboards for entering text in various applications (e.g., contacts  1037 , e-mail  1040 , IM  1041 , browser  1047 , and any other application that needs text input). 
     GPS module  1035  determines the location of the device and provides this information for use in various applications (e.g., to telephone  1038  for use in location-based dialing, to camera  1043  as picture/video metadata, and to applications that provide location-based services such as weather widgets, local yellow page widgets, and map/navigation widgets). 
     Applications  1036  may include the following modules (or sets of instructions), or a subset or superset thereof:
         contacts module  1037  (sometimes called an address book or contact list);   telephone module  1038 ;   video conferencing module  1039 ;   e-mail client module  1040 ;   instant messaging (IM) module  1041 ;   workout support module  1042 ;   camera module  1043  for still and/or video images;   image management module  1044 ;   browser module  1047 ;   calendar module  1048 ;   widget modules  1049 , which may include one or more of: weather widget  1049 - 1 , stocks widget  1049 - 2 , calculator widget  1049 - 3 , alarm clock widget  1049 - 4 , dictionary widget  1049 - 5 , and other widgets obtained by the user, as well as user-created widgets  1049 - 6 ;   widget creator module  1050  for making user-created widgets  1049 - 6 ;   search module  1051 ;   video and music player module  1052 , which may be made up of a video player   module and a music player module;   notes module  1053 ;   map module  1054 ; and/or   online video module  1505 .       

     Examples of other applications  1036  that may be stored in memory  1002  include other word processing applications, other image editing applications, drawing applications, presentation applications, JAVA-enabled applications, encryption, digital rights management, voice recognition, and voice replication. 
     In conjunction with touch screen  1012 , display controller  1056 , contact module  1030 , graphics module  1032 , and text input module  1034 , contacts module  1037  may be used to manage an address book or contact list (e.g., stored in application internal state  1092  of contacts module  1037  in memory  1002 ), including: adding name(s) to the address book; deleting name(s) from the address book; associating telephone number(s), e-mail address(es), physical address(es) or other information with a name; associating an image with a name; categorizing and sorting names; providing telephone numbers or e-mail addresses to initiate and/or facilitate communications by telephone  1038 , video conference  1039 , e-mail  1040 , or IM  1041 ; and so forth. 
     In conjunction with RF circuitry  1008 , audio circuitry  1010 , speaker  1011 , microphone  1013 , touch screen  1012 , display controller  1056 , contact module  1030 , graphics module  1032 , and text input module  1034 , telephone module  1038  may be used to enter a sequence of characters corresponding to a telephone number, access one or more telephone numbers in address book  1037 , modify a telephone number that has been entered, dial a respective telephone number, conduct a conversation and disconnect or hang up when the conversation is completed. As noted above, the wireless communication may use any of multiple communications standards, protocols and technologies. 
     In conjunction with RF circuitry  1008 , audio circuitry  1010 , speaker  1011 , microphone  1013 , touch screen  1012 , display controller  1056 , optical sensor  1064 , optical sensor controller  1058 , contact module  1030 , graphics module  1032 , text input module  1034 , contact list  1037 , and telephone module  1038 , videoconferencing module  1039  includes executable instructions to initiate, conduct, and terminate a video conference between a user and one or more other participants in accordance with user instructions. 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display controller  1056 , contact module  1030 , graphics module  1032 , and text input module  1034 , e-mail client module  1040  includes executable instructions to create, send, receive, and manage e-mail in response to user instructions. In conjunction with image management module  1044 , e-mail client module  1040  makes it very easy to create and send e-mails with still or video images taken with camera module  1043 . 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display controller  1056 , contact module  1030 , graphics module  1032 , and text input module  1034 , the instant messaging module  1041  includes executable instructions to enter a sequence of characters corresponding to an instant message, to modify previously entered characters, to transmit a respective instant message (for example, using a Short Message Service (SMS) or Multimedia Message Service (MMS) protocol for telephony-based instant messages or using XMPP, SIMPLE, or IMPS for Internet-based instant messages), to receive instant messages and to view received instant messages. In some embodiments, transmitted and/or received instant messages may include graphics, photos, audio files, video files and/or other attachments as are supported in a MMS and/or an Enhanced Messaging Service (EMS). As used herein, “instant messaging” refers to both telephony-based messages (e.g., messages sent using SMS or MMS) and Internet-based messages (e.g., messages sent using XMPP, SIMPLE, or IMPS). 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display controller  1056 , contact module  1030 , graphics module  1032 , text input module  1034 , GPS module  1035 , map module  1054 , and music player module  1046 , workout support module  1042  includes executable instructions to create workouts (e.g., with time, distance, and/or calorie burning goals); communicate with workout sensors (sports devices); receive workout sensor data; calibrate sensors used to monitor a workout; select and play music for a workout; and display, store and transmit workout data. 
     In conjunction with touch screen  1012 , display controller  1056 , optical sensor(s)  1064 , optical sensor controller  1058 , contact module  1030 , graphics module  1032 , and image management module  1044 , camera module  1043  includes executable instructions to capture still images or video (including a video stream) and store them into memory  1002 , modify characteristics of a still image or video, or delete a still image or video from memory  1002 . 
     In conjunction with touch screen  1012 , display controller  1056 , contact module  1030 , graphics module  1032 , text input module  1034 , and camera module  1043 , image management module  1044  includes executable instructions to arrange, modify (e.g., edit), or otherwise manipulate, label, delete, present (e.g., in a digital slide show or album), and store still and/or video images. 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  1032 , and text input module  1034 , browser module  1047  includes executable instructions to browse the Internet in accordance with user instructions, including searching, linking to, receiving, and displaying web pages or portions thereof, as well as attachments and other files linked to web pages. 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  1032 , text input module  1034 , e-mail client module  1040 , and browser module  1047 , calendar module  1048  includes executable instructions to create, display, modify, and store calendars and data associated with calendars (e.g., calendar entries, to do lists, etc.) in accordance with user instructions. 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  1032 , text input module  1034 , and browser module  1047 , widget modules  1049  are mini-applications that may be downloaded and used by a user (e.g., weather widget  1049 - 1 , stocks widget  1049 - 2 , calculator widget  10493 , alarm clock widget  1049 - 4 , and dictionary widget  1049 - 5 ) or created by the user (e.g., user-created widget  1049 - 6 ). In some embodiments, a widget includes an HTML (Hypertext Markup Language) file, a CSS (Cascading Style Sheets) file, and a JavaScript file. In some embodiments, a widget includes an XML (Extensible Markup Language) file and a JavaScript file (e.g., Yahoo! Widgets). 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  102 , text input module  1034 , and browser module  1047 , the widget creator module  1050  may be used by a user to create widgets (e.g., turning a user-specified portion of a web page into a widget). 
     In conjunction with touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  1032 , and text input module  1034 , search module  1051  includes executable instructions to search for text, music, sound, image, video, and/or other files in memory  1002  that match one or more search criteria (e.g., one or more user-specified search terms) in accordance with user instructions. 
     In conjunction with touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  1032 , audio circuitry  1010 , speaker  1011 , RF circuitry  1008 , and browser module  1047 , video and music player module  1052  includes executable instructions that allow the user to download and play back recorded music and other sound files stored in one or more file formats, such as MP3 or AAC files, and executable instructions to display, present or otherwise play back videos (e.g., on touch screen  1012  or on an external, connected display via external port  1024 ). In some embodiments, device  1000  may include the functionality of an MP3 player, such as an iPod (trademark of Apple Inc.). 
     In conjunction with touch screen  1012 , display controller  1056 , contact module  1030 , graphics module  1032 , and text input module  1034 , notes module  1053  includes executable instructions to create and manage notes, to do lists, and the like in accordance with user instructions. 
     In conjunction with RF circuitry  1008 , touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  1032 , text input module  1034 , GPS module  1035 , and browser module  1047 , map module  1054  may be used to receive, display, modify, and store maps and data associated with maps (e.g., driving directions; data on stores and other points of interest at or near a particular location; and other location-based data) in accordance with user instructions. 
     In conjunction with touch screen  1012 , display system controller  1056 , contact module  1030 , graphics module  1032 , audio circuitry  1010 , speaker  1011 , RF circuitry  1008 , text input module  1034 , e-mail client module  1040 , and browser module  1047 , online video module  1055  includes instructions that allow the user to access, browse, receive (e.g., by streaming and/or download), play back (e.g., on the touch screen or on an external, connected display via external port  1024 ), send an e-mail with a link to a particular online video, and otherwise manage online videos in one or more file formats, such as H.264. In some embodiments, instant messaging module  1041 , rather than e-mail client module  1040 , is used to send a link to a particular online video. 
     Each of the above identified modules and applications correspond to a set of executable instructions for performing one or more functions described above and the methods described in this application (e.g., the computer-implemented methods and other information processing methods described herein). These modules (i.e., sets of instructions) need not be implemented as separate software programs, procedures or modules, and thus various subsets of these modules may be combined or otherwise re-arranged in various embodiments. In some embodiments, memory  1002  may store a subset of the modules and data structures identified above. Furthermore, memory  1002  may store additional modules and data structures not described above. 
     In some embodiments, device  1000  is a device where operation of a predefined set of functions on the device is performed exclusively through a touch screen and/or a touchpad. By using a touch screen and/or a touchpad as the primary input control device for operation of device  1000 , the number of physical input control devices (such as push buttons, dials, and the like) on device  1000  may be reduced. 
     The predefined set of functions that may be performed exclusively through a touch screen and/or a touchpad include navigation between user interfaces. In some embodiments, the touchpad, when touched by the user, navigates device  1000  to a main, home, or root menu from any user interface that may be displayed on device  1000 . In such embodiments, the touchpad may be referred to as a “menu button.” In some other embodiments, the menu button may be a physical push button or other physical input control device instead of a touchpad. 
       FIG. 10B  is a block diagram illustrating exemplary components for event handling in accordance with some embodiments. In some embodiments, memory  1002  (in  FIG. 10A ) includes event sorter  1070  (e.g., in operating system  1026 ) and a respective application  1036 - 1  (e.g., any of the aforementioned applications  1037 - 1051 ,  1055 ). 
     Event sorter  1070  receives event information and determines the application  1036 - 1  and application view  1091  of application  1036 - 1  to which to deliver the event information. Event sorter  1070  includes event monitor  1071  and event dispatcher module  1074 . In some embodiments, application  1036 - 1  includes application internal state  1092 , which indicates the current application view(s) displayed on touch sensitive display  1012  when the application is active or executing. In some embodiments, device/global internal state  1057  is used by event sorter  1070  to determine which application(s) is (are) currently active, and application internal state  1092  is used by event sorter  1070  to determine application views  1091  to which to deliver event information. 
     In some embodiments, application internal state  1092  includes additional information, such as one or more of: resume information to be used when application  1036 - 1  resumes execution, user interface state information that indicates information being displayed or that is ready for display by application  1036 - 1 , a state queue for enabling the user to go back to a prior state or view of application  1036 - 1 , and a redo/undo queue of previous actions taken by the user. 
     Event monitor  1071  receives event information from peripherals interface  1018 . Event information includes information about a sub-event (e.g., a user touch on touch sensitive display  1012 , as part of a multi-touch gesture). Peripherals interface  1018  transmits information it receives from I/O subsystem  1006  or a sensor, such as proximity sensor  1066 , orientation sensor(s)  1068 , and/or microphone  1013  (through audio circuitry  1010 ). Information that peripherals interface  1018  receives from I/O subsystem  1006  includes information from touch-sensitive display  1012  or a touch-sensitive surface. 
     In some embodiments, event monitor  1071  sends requests to the peripherals interface  1018  at predetermined intervals. In response, peripherals interface  1018  transmits event information. In other embodiments, peripheral interface  1018  transmits event information only when there is a significant event (e.g., receiving an input above a predetermined noise threshold and/or for more than a predetermined duration). 
     In some embodiments, event sorter  1070  also includes a hit view determination module  1072  and/or an active event recognizer determination module  1073 . 
     Hit view determination module  1072  provides software procedures for determining where a sub-event has taken place within one or more views, when touch sensitive display  1012  displays more than one view. Views are made up of controls and other elements that a user can see on the display. 
     Another aspect of the user interface associated with an application is a set of views, sometimes herein called application views or user interface windows, in which information is displayed and touch-based gestures occur. The application views (of a respective application) in which a touch is detected may correspond to programmatic levels within a programmatic or view hierarchy of the application. For example, the lowest level view in which a touch is detected may be called the hit view, and the set of events that are recognized as proper inputs may be determined based, at least in part, on the hit view of the initial touch that begins a touch-based gesture. 
     Hit view determination module  1072  receives information related to sub-events of a touch-based gesture. When an application has multiple views organized in a hierarchy, hit view determination module  1072  identifies a hit view as the lowest view in the hierarchy which should handle the sub-event. In most circumstances, the hit view is the lowest level view in which an initiating sub-event occurs (i.e., the first sub-event in the sequence of sub-events that form an event or potential event). Once the hit view is identified by the hit view determination module, the hit view typically receives all sub-events related to the same touch or input source for which it was identified as the hit view. 
     Active event recognizer determination module  1073  determines which view or views within a view hierarchy should receive a particular sequence of sub-events. In some embodiments, active event recognizer determination module  1073  determines that only the hit view should receive a particular sequence of sub-events. In other embodiments, active event recognizer determination module  1073  determines that all views that include the physical location of a sub-event are actively involved views, and therefore determines that all actively involved views should receive a particular sequence of sub-events. In other embodiments, even if touch sub-events were entirely confined to the area associated with one particular view, views higher in the hierarchy would still remain as actively involved views. 
     Event dispatcher module  1074  dispatches the event information to an event recognizer (e.g., event recognizer  1080 ). In embodiments including active event recognizer determination module  1073 , event dispatcher module  1074  delivers the event information to an event recognizer determined by active event recognizer determination module  1073 . In some embodiments, event dispatcher module  1074  stores in an event queue the event information, which is retrieved by a respective event receiver module  1082 . 
     In some embodiments, operating system  1026  includes event sorter  1070 . Alternatively, application  1036 - 1  includes event sorter  1070 . In yet other embodiments, event sorter  1070  is a stand-alone module, or a part of another module stored in memory  1002 , such as contact/motion module  1030 . 
     In some embodiments, application  1036 - 1  includes multiple event handlers  1090  and one or more application views  1091 , each of which includes instructions for handling touch events that occur within a respective view of the application&#39;s user interface. Each application view  1091  of the application  1036 - 1  includes one or more event recognizers  1080 . Typically, a respective application view  1091  includes multiple event recognizers  1080 . In other embodiments, one or more of event recognizers  1080  are part of a separate module, such as a user interface kit (not shown) or a higher level object from which application  1036 - 1  inherits methods and other properties. In some embodiments, a respective event handler  1090  includes one or more of: data updater  1076 , object updater  1077 , GUI updater  1078 , and/or event data  1079  received from event sorter  1070 . Event handler  1090  may utilize or call data updater  1076 , object updater  1077  or GUI updater  1078  to update the application internal state  1092 . Alternatively, one or more of the application views  1091  includes one or more respective event handlers  1090 . Also, in some embodiments, one or more of data updater  1076 , object updater  1077 , and GUI updater  1078  are included in a respective application view  1091 . 
     A respective event recognizer  1080  receives event information (e.g., event data  1079 ) from event sorter  1070 , and identifies an event from the event information. Event recognizer  1080  includes event receiver  1082  and event comparator  1084 . In some embodiments, event recognizer  1080  also includes at least a subset of: metadata  1083 , and event delivery instructions  1088  (which may include sub-event delivery instructions). 
     Event receiver  1082  receives event information from event sorter  1070 . The event information includes information about a sub-event, for example, a touch or a touch movement. Depending on the sub-event, the event information also includes additional information, such as location of the sub-event. When the sub-event concerns motion of a touch the event information may also include speed and direction of the sub-event. In some embodiments, events include rotation of the device from one orientation to another (e.g., from a portrait orientation to a landscape orientation, or vice versa), and the event information includes corresponding information about the current orientation (also called device attitude) of the device. 
     Event comparator  1084  compares the event information to predefined event or sub-event definitions and, based on the comparison, determines an event or sub-event, or determines or updates the state of an event or sub-event. In some embodiments, event comparator  1084  includes event definitions  1086 . Event definitions  1086  contain definitions of events (e.g., predefined sequences of sub-events), for example, event  1  ( 1087 - 1 ), event  2  ( 1087 - 2 ), and others. In some embodiments, sub-events in an event  1087  include, for example, touch begin, touch end, touch movement, touch cancellation, and multiple touching. In one example, the definition for event  1  ( 1087 - 1 ) is a double tap on a displayed object. The double tap, for example, includes a first touch (touch begin) on the displayed object for a predetermined phase, a first lift-off (touch end) for a predetermined phase, a second touch (touch begin) on the displayed object for a predetermined phase, and a second lift-off (touch end) for a predetermined phase. In another example, the definition for event  2  ( 1087 - 2 ) is a dragging on a displayed object. The dragging, for example, includes a touch (or contact) on the displayed object for a predetermined phase, a movement of the touch across touch-sensitive display  1012 , and lift-off of the touch (touch end). In some embodiments, the event also includes information for one or more associated event handlers  1090 . 
     In some embodiments, event definition  1087  includes a definition of an event for a respective user-interface object. In some embodiments, event comparator  1084  performs a hit test to determine which user-interface object is associated with a sub-event. For example, in an application view in which three user-interface objects are displayed on touch-sensitive display  1012 , when a touch is detected on touch-sensitive display  1012 , event comparator  1084  performs a hit test to determine which of the three user-interface objects is associated with the touch (sub-event). If each displayed object is associated with a respective event handler  1090 , the event comparator uses the result of the hit test to determine which event handler  1090  should be activated. For example, event comparator  1084  selects an event handler associated with the sub-event and the object triggering the hit test. 
     In some embodiments, the definition for a respective event  1087  also includes delayed actions that delay delivery of the event information until after it has been determined whether the sequence of sub-events does or does not correspond to the event recognizer&#39;s event type. 
     When a respective event recognizer  1080  determines that the series of sub-events do not match any of the events in event definitions  1086 , the respective event recognizer  1080  enters an event impossible, event failed, or event ended state, after which it disregards subsequent sub-events of the touch-based gesture. In this situation, other event recognizers, if any, that remain active for the hit view continue to track and process sub-events of an ongoing touch-based gesture. 
     In some embodiments, a respective event recognizer  1080  includes metadata  1083  with configurable properties, flags, and/or lists that indicate how the event delivery system should perform sub-event delivery to actively involved event recognizers. In some embodiments, metadata  1083  includes configurable properties, flags, and/or lists that indicate how event recognizers may interact with one another. In some embodiments, metadata  1083  includes configurable properties, flags, and/or lists that indicate whether sub-events are delivered to varying levels in the view or programmatic hierarchy. 
     In some embodiments, a respective event recognizer  1080  activates event handler  1090  associated with an event when one or more particular sub-events of an event are recognized. In some embodiments, a respective event recognizer  1080  delivers event information associated with the event to event handler  190 . Activating an event handler  1090  is distinct from sending (and deferred sending) sub-events to a respective hit view. In some embodiments, event recognizer  1080  throws a flag associated with the recognized event, and event handler  1090  associated with the flag catches the flag and performs a predefined process. 
     In some embodiments, event delivery instructions  1088  include sub-event delivery instructions that deliver event information about a sub-event without activating an event handler. Instead, the sub-event delivery instructions deliver event information to event handlers associated with the series of sub-events or to actively involved views. Event handlers associated with the series of sub-events or with actively involved views receive the event information and perform a predetermined process. 
     In some embodiments, data updater  1076  creates and updates data used in application  1036 - 1 . For example, data updater  1076  updates the telephone number used in contacts module  1037 , or stores a video file used in video player module  1045 . In some embodiments, object updater  1077  creates and updates objects used in application  1036 - 1 . For example, object updater  1076  creates a new user-interface object or updates the position of a user-interface object. GUI updater  1078  updates the GUI. For example, GUI updater  1078  prepares display information and sends it to graphics module  1032  for display on a touch-sensitive display. 
     In some embodiments, event handler(s)  1090  includes or has access to data updater  1076 , object updater  1077 , and GUI updater  1078 . In some embodiments, data updater  1076 , object updater  1077 , and GUI updater  1078  are included in a single module of a respective application  1036 - 1  or application view  1091 . In other embodiments, they are included in two or more software modules. 
     It shall be understood that the foregoing discussion regarding event handling of user touches on touch-sensitive displays also applies to other forms of user inputs to operate multifunction devices  1000  with input-devices, not all of which are initiated on touch screens, e.g., coordinating mouse movement and mouse button presses with or without single or multiple keyboard presses or holds, user movements taps, drags, scrolls, etc., on touch-pads, pen stylus inputs, movement of the device, oral instructions, detected eye movements, biometric inputs, and/or any combination thereof, which may be utilized as inputs corresponding to sub-events which define an event to be recognized. 
       FIG. 11  illustrates a portable multifunction device  1000  having a touch screen  1012  in accordance with some embodiments. The touch screen may display one or more graphics within user interface (UI)  1100 . In this embodiment, as well as others described below, a user may select one or more of the graphics by making a gesture on the graphics, for example, with one or more fingers  1102  (not drawn to scale in the figure) or one or more styluses  1103  (not drawn to scale in the figure). In some embodiments, selection of one or more graphics occurs when the user breaks contact with the one or more graphics. In some embodiments, the gesture may include one or more taps, one or more swipes (from left to right, right to left, upward and/or downward) and/or a rolling of a finger (from right to left, left to right, upward and/or downward) that has made contact with device  1000 . In some embodiments, inadvertent contact with a graphic may not select the graphic. For example, a swipe gesture that sweeps over an application icon may not select the corresponding application when the gesture corresponding to selection is a tap. 
     Device  1000  may also include one or more physical buttons, such as “home” or menu button  1104 . As described previously, menu button  1104  may be used to navigate to any application  1036  in a set of applications that may be executed on device  1000 . Alternatively, in some embodiments, the menu button is implemented as a soft key in a GUI displayed on touch screen  1012 . 
     In one embodiment, device  1000  includes touch screen  1112 , menu button  1104 , push button  1106  for powering the device on/off and locking the device, volume adjustment button(s)  1108 , Subscriber Identity Module (SIM) card slot  1110 , head set jack  1112 , and docking/charging external port  1024 . Push button  1106  may be used to turn the power on/off on the device by depressing the button and holding the button in the depressed state for a predefined time interval; to lock the device by depressing the button and releasing the button before the predefined time interval has elapsed; and/or to unlock the device or initiate an unlock process. In an alternative embodiment, device  1000  also may accept verbal input for activation or deactivation of some functions through microphone  1013 . 
     It should be noted that, although many of the following examples will be given with reference to inputs on touch screen  1012  (where the touch sensitive surface and the display are combined), a touch-sensitive surface that is separate from the display may be used instead of touch screen  1012 . 
     Example Computer System 
     Various embodiments of the system and method for tile-based reduction of access point location information, as described herein, may be executed on one or more computer systems, which may interact with various other devices. Note that any component, action, or functionality described above with respect to  FIGS. 1-11 and 13  (described below) may be implemented on one or more computers configured as computer system  1200  of  FIG. 12 , according to various embodiments. In the illustrated embodiment, computer system  1200  includes one or more processors  1210  coupled to a system memory  1220  via an input/output (I/O) interface  1230 . Computer system  1200  further includes a network interface  1240  coupled to I/O interface  1230 , and one or more input/output devices  1250 , such as cursor control device  1260 , keyboard  1270 , and display(s)  1280 . In some cases, it is contemplated that embodiments may be implemented using a single instance of computer system  1200 , while in other embodiments multiple such systems, or multiple nodes making up computer system  1200 , may be configured to host different portions or instances of embodiments. For example, in one embodiment some elements may be implemented via one or more nodes of computer system  1200  that are distinct from those nodes implementing other elements. 
     In various embodiments, computer system  1200  may be a uniprocessor system including one processor  1210 , or a multiprocessor system including several processors  1210  (e.g., two, four, eight, or another suitable number). Processors  1210  may be any suitable processor capable of executing instructions. For example, in various embodiments processors  1210  may be general-purpose or embedded processors implementing any of a variety of instruction set architectures (ISAs), such as the x86, PowerPC, SPARC, or MIPS ISAs, or any other suitable ISA. In multiprocessor systems, each of processors  1210  may commonly, but not necessarily, implement the same ISA. 
     System memory  1220  may be configured to store program instructions  1222  and/or data  1232  accessible by processor  1210 . In various embodiments, system memory  1220  may be implemented using any suitable memory technology, such as static random access memory (SRAM), synchronous dynamic RAM (SDRAM), nonvolatile/Flash-type memory, or any other type of memory. In the illustrated embodiment, program instructions  1222  may be configured to implement a mapping application  1224  incorporating any of the functionality described above. Additionally, data  1232  of memory  1220  may include mapping information  1234  including any of the information or data structures described above, including but not limited to mapping information for rendering map instances, position information indicating past or current positions of the user, and/or route information for navigating from an origination to a destination. In some embodiments, program instructions and/or data may be received, sent or stored upon different types of computer-accessible media or on similar media separate from system memory  1220  or computer system  1200 . While computer system  1200  is described as implementing the functionality of functional blocks of previous Figures, any of the functionality described herein may be implemented via such a computer system. 
     In one embodiment, I/O interface  1230  may be configured to coordinate I/O traffic between processor  1210 , system memory  1220 , and any peripheral devices in the device, including network interface  1240  or other peripheral interfaces, such as input/output devices  1250 . In some embodiments, I/O interface  1230  may perform any necessary protocol, timing or other data transformations to convert data signals from one component (e.g., system memory  1220 ) into a format suitable for use by another component (e.g., processor  1210 ). In some embodiments, I/O interface  1230  may include support for devices attached through various types of peripheral buses, such as a variant of the Peripheral Component Interconnect (PCI) bus standard or the Universal Serial Bus (USB) standard, for example. In some embodiments, the function of I/O interface  1230  may be split into two or more separate components, such as a north bridge and a south bridge, for example. Also, in some embodiments some or all of the functionality of I/O interface  1230 , such as an interface to system memory  1220 , may be incorporated directly into processor  1210 . 
     Network interface  1240  may be configured to allow data to be exchanged between computer system  1200  and other devices attached to a network  1285  (e.g., carrier or agent devices) or between nodes of computer system  1200 . Network  1285  may in various embodiments include one or more networks including but not limited to Local Area Networks (LANs) (e.g., an Ethernet or corporate network), Wide Area Networks (WANs) (e.g., the Internet), wireless data networks, some other electronic data network, or some combination thereof. In various embodiments, network interface  1240  may support communication via wired or wireless general data networks, such as any suitable type of Ethernet network, for example; via telecommunications/telephony networks such as analog voice networks or digital fiber communications networks; via storage area networks such as Fibre Channel SANs, or via any other suitable type of network and/or protocol. 
     Input/output devices  1250  may, in some embodiments, include one or more display terminals, keyboards, keypads, touchpads, scanning devices, voice or optical recognition devices, or any other devices suitable for entering or accessing data by one or more computer systems  1200 . Multiple input/output devices  1250  may be present in computer system  1200  or may be distributed on various nodes of computer system  1200 . In some embodiments, similar input/output devices may be separate from computer system  1200  and may interact with one or more nodes of computer system  1200  through a wired or wireless connection, such as over network interface  1240 . 
     As shown in  FIG. 12 , memory  1220  may include program instructions  1222 , which may be processor-executable to implement any element or action described above. In one embodiment, the program instructions may implement the methods described above. In other embodiments, different elements and data may be included. Note that data  1232  may include any data or information described above. 
     Those skilled in the art will appreciate that computer system  1200  is merely illustrative and is not intended to limit the scope of embodiments. In particular, the computer system and devices may include any combination of hardware or software that can perform the indicated functions, including computers, network devices, Internet appliances, PDAs, wireless phones, pagers, etc. Computer system  1200  may also be connected to other devices that are not illustrated, or instead may operate as a stand-alone system. In addition, the functionality provided by the illustrated components may in some embodiments be combined in fewer components or distributed in additional components. Similarly, in some embodiments, the functionality of some of the illustrated components may not be provided and/or other additional functionality may be available. 
     Those skilled in the art will also appreciate that, while various items are illustrated as being stored in memory or on storage while being used, these items or portions of them may be transferred between memory and other storage devices for purposes of memory management and data integrity. Alternatively, in other embodiments some or all of the software components may execute in memory on another device and communicate with the illustrated computer system via inter-computer communication. Some or all of the system components or data structures may also be stored (e.g., as instructions or structured data) on a computer-accessible medium or a portable article to be read by an appropriate drive, various examples of which are described above. In some embodiments, instructions stored on a computer-accessible medium separate from computer system  1200  may be transmitted to computer system  1200  via transmission media or signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as a network and/or a wireless link. Various embodiments may further include receiving, sending or storing instructions and/or data implemented in accordance with the foregoing description upon a computer-accessible medium. Generally speaking, a computer-accessible medium may include a computer-readable storage medium or memory medium such as magnetic or optical media, e.g., disk or DVD/CD-ROM, volatile or non-volatile media such as RAM (e.g. SDRAM, DDR, RDRAM, SRAM, etc.), ROM, etc. In some embodiments, a computer-accessible medium may include transmission media or signals such as electrical, electromagnetic, or digital signals, conveyed via a communication medium such as network and/or a wireless link. 
     As illustrated in  FIG. 13 , one or more computers (e.g., computer system  1200 ) may be configured to implement the functional components described herein including but not limited to collection service  110 , tile generator  200 , and tile service  320 . For instance, one or more host systems  1330  may each represent one or more computer systems  1200 . One or more multifunction devices  1300  may be configured to communicate with host systems  1330  via one or more electronic networks  1320 , such as the Internet or any other network described above with respect to network  1285 . In various embodiments, multifunction devices may access a network through one or more access points, illustrated as AP  1310 . In various embodiments, AP  1310  (e.g., an IEEE 802.11g wireless access point) can provide communication access to one or more of networks  1320 . In some embodiments, data communications can be established over network  1320  and access point  1310 . For example, multifunction device  1300  can send and receive e-mail messages (e.g., using Simple Mail Transfer Protocol (SMTP) or Post Office Protocol 3 (POP3)), and retrieve electronic documents and/or streams, such as web pages, photographs, and videos, over network  1320  and AP  1310  (e.g., using Transmission Control Protocol/Internet Protocol (TCP/IP) or User Datagram Protocol (UDP)). In various embodiments, any of the multifunction devices may communicate with the services hosted by host systems  1330  using a persistent connection established in accordance with one or more security protocols, such as the Secure Sockets Layer (SSL) protocol or the Transport Layer Security (TLS) protocol. 
     Various modifications and changes may be made as would be obvious to a person skilled in the art having the benefit of this disclosure. The various embodiments described herein are meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances may be provided for components described herein as a single instance. Boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of claims that follow. Finally, structures and functionality presented as discrete components in the exemplary configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of embodiments as defined in the claims that follow.

Metadata:
Filing Date: 20120911
Publication Date: 20180807
Grant Date: 20180807
Priority Date: 20120608
Inventors: Grosman, Yefim
MAYOR, ROBERT W.
HUANG, RONALD K.
KONSTANTINOV, ANDREW
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W24/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01S5/0242", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/10", "inventive": false, "first": false, "tree": "[]"}, {"code": "G01S5/0242", "inventive": true, "first": true, "tree": "[]"}, {"code": "G01S5/0242", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 49715703