Patent Publication Number: US-11385061-B2

Title: Navigation using short-range transmissions

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/798,007, filed Oct. 30, 2017, which is herein incorporated in its entirety by reference. 
    
    
     BACKGROUND 
     1. Field 
     This disclosure generally relates to providing navigation to geographic locations for a network system, and more specifically to using signatures of short-range transmissions for navigating to pickup locations for services provided via the network system. 
     2. Description of the Related Art 
     In a network system, providers provide geographic location-based services to users, for example, a provider uses a vehicle to transport a user. Users can manually search for a pickup location, that is, the location at which they want the provider to pick them up to start a trip. However, searching for pickup locations may be difficult when users are located somewhere that does not have reception of global positioning system (GPS) signals, such as inside a building that may block out GPS signals. Further, in situations where a user is located at a large venue or building such as a shopping mall with multiple possible pickup locations within vicinity of each other, a conventional system may not reliably resolve the user&#39;s desired pickup location. For example, there are exits on both a north and south side of the shopping mall, but the system does not receive GPS signal data with enough granularity to determine which of the two locations is the user&#39;s desired pickup location. Moreover, the user may not know directions to the pickup location, or for instance, the user arrives at the north exit of the mall believing that it is actually the south exit, causing a delay in pickup by the provider. Providing inaccurate pickup locations, or inaccurate navigation to pickup locations, results in a poor user experience, which may cause users to stop using services of the system. 
     SUMMARY 
     A network system uses Wi-Fi signals or other types of short-range transmissions to determine navigation to pickup locations for users receiving services provided via the network system. For example, a particular user inside a building requests transportation service and wants a provider to pick up the particular user for the transportation service at a certain exit of the building. Thus, even if the particular user&#39;s client device does not have reliable GPS signal reception (e.g., inside the building or underground), the network system can still determine where the particular user is located and a route from the particular user&#39;s current location to a pickup location. 
     The network system includes a database of reference signatures of short-range transmission previously detected by other client devices of users when the other client devices were located at various locations within or nearby a geographical region such as the building. In some embodiments, the networks system maps the reference signatures to the corresponding locations of the geographical region. Accordingly, by leveraging the database, the network system may determine a current location of the particular user by checking for similarities between signatures detected by the client device of the particular user and the reference signatures. In addition, the network system may determine a route from the current location to the pickup location using the signatures and without necessarily using other sensor data such as GPS signals. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a diagram of a system environment for a network system according to one embodiment. 
         FIG. 2  is a block diagram illustrating the architecture of the network system according to one embodiment. 
         FIG. 3  is a diagram of broadcasters in a building according to one embodiment. 
         FIG. 4  is a set of diagrams showing signatures of short-range transmissions detected from the broadcasters shown in  FIG. 3  according to one embodiment. 
         FIG. 5  is a flowchart illustrating a process for determining a route to a pickup location according to one embodiment. 
         FIG. 6  is a high-level block diagram illustrating physical components of a computer used as part or all of the components from  FIG. 1 , according to one embodiment. 
     
    
    
     The figures depict embodiments of the present invention for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the invention described herein. 
     DETAILED DESCRIPTION 
     I. System Overview 
       FIG. 1  is a diagram of a system environment for a network system  100  according to one embodiment. Users of the network system  100  may include providers that provide service to other users. In an example use case, a provider operates a vehicle to transport a user from a first location, referred to herein as a “pickup location,” to a second location, referred to herein as a “destination location.” The network system  100  may determine pickup locations and coordinate providers to pick up users at the pickup locations. In some use cases, there may be multiple pickup locations nearby a geographical region (e.g., within a threshold radius or a predetermined boundary). For instance, a user may be picked up one of multiple exits of a building (e.g., on the north, east, south, or west side), which may also be located at different floors of the building. The network system  100  may provide navigation for the user to travel from a current location in the building to a pickup location at a particular exit. Other types of services provided via the network system  100  include, for example, delivery of goods such as mail, packages, or consumable items. 
     The system environment includes the network system  100  and one or more client devices  110  of users of the network system  100 , for example, client device  110 A of a user and client device  110 B of a provider providing service to the user, which may collectively be referred to herein as a “client device  110 ” or “client devices  110 .” The network system  100  and client devices  110  are connected to each other via a network  130 . Additionally, the system environment includes one or more broadcasters  120  that transmit short-range transmissions such as Wi-Fi, BLUETOOTH®, or infrared (IR) signals. A broadcaster  120  may be a Wi-Fi router, a BLUETOOTH® beacon, an infrared beacon, or any other suitable device that transmits short-range transmissions. In some embodiments, a broadcaster  120  is optionally connected to one or more of the other components shown in  FIG. 1  via the network  130 . In other embodiments, different or additional entities can be included in the system environment. The functions performed by the various entities of  FIG. 1  may vary in different embodiments. 
     A user can interact with the network system  100  through the client device  110 , e.g., to request service or to receive requests to provide service. A client device  110  can be a personal or mobile computing device, such as a smartphone, a tablet, or a notebook computer. In some embodiments, the client device  110  executes a client application that uses an application programming interface (API) to communicate with the network system  100  through the network  130 . The client application of the client device  110  can present information received from the network system  100  on a user interface, such as a geographic map (e.g., within a building or outdoors), current location of the client device  110 , or route to a pickup location. In some embodiments, the client application running on the client device  110  can determine the current location using one or more sensors of the client device  110 , such as a global positioning system (GPS) receiver, and provide the current location to the network system  100 . 
     In addition, or alternatively, to a GPS receiver, the client device  110  may include other sensors such as a Wi-Fi radio (or receiver), a BLUETOOTH® radio, a camera (e.g., capable of detecting IR signals), or a motion sensor. The Wi-Fi and BLUETOOTH® radios detect short-range transmissions such as Wi-Fi and BLUETOOTH® signals, respectively. Motion sensors include, e.g., accelerometers, gyroscopes, magnetic sensors, inertial measurement units (IMUs), and the like. The motion sensors can capture telematics data describing motion or bearing of the user or a vehicle in which the user traveling. The client device  110  can provide detected signatures of the short-range transmissions along with the telematics data to the network system  100  for further processing. 
     In one embodiment, through operation of the client device  110 , a user makes a trip request to the network system  100 . The trip request provided by the client application to the network system  100  includes, for example, user identification information, the number of passengers for the trip, a requested type of the service provider (e.g., a vehicle type or service option identifier), a signature of short-range transmission detected by the client device  110 , telematics data, a current location of the client device  110 , or a pickup location or destination location for the trip. The user may input data for the trip request via a user interface of the client device  110 . For example, the user inputs text describing the pickup or destination location for a trip using a touchscreen keyboard of the client device  110 . 
     In some embodiments, a provider uses a client device  110  to interact with the network system  100  and receive invitations to provide service for users. For example, the provider is a person operating a vehicle capable of transporting users. In some embodiments, the provider is an autonomous vehicle that receives routing instructions from the network system  100 . For convenience, this disclosure generally uses a car as the vehicle, which is operated by a driver as an example provider. However, the embodiments described herein may be adapted for a provider operating alternative vehicles (e.g., boat, airplane, helicopter, VTOL, etc.) or vehicles that do not necessarily need to be operated by a person. 
     In some embodiments, a provider can receive invitations or assignment requests through a client device  110 . An assignment request identifies a user who submitted a trip request to the network system  100  and determines the pickup location or the destination location of the user for a trip. For example, the network system  100  can receive a trip request from a client device  110  of a user, select a service provider from a pool of available (or “open”) providers to provide the trip, e.g., based on the vehicle type, determined pickup location, a signature of short-range transmission, or the destination location. The network system  100  transmits an assignment request to the selected provider&#39;s client device  110 . 
     Client devices  110  can communicate with the network system  100  via the network  130 , which may comprise any combination of local area and wide area networks employing wired or wireless communication links. In one embodiment, the network  130  uses standard communications technologies and Internet protocols. For example, the network  130  includes communication links using technologies such as the Internet, 3G, 4G, BLUETOOTH®, or Wi-Fi. In some embodiments, all or some of the communication links of the network  130  may be encrypted. 
     II. Example System Architecture 
       FIG. 2  is a block diagram illustrating the architecture of a network system  100  according to one embodiment. The network system  100  includes a matching engine  200 , map data store  205 , user data store  210 , navigation engine  220 , signature data store  225 , and signal processing engine  230 . In other embodiments, the network system  100  may include additional, fewer, or different components for various applications. 
     In some embodiments, users and providers use their client devices  110  to register with the network system  100 , for example, by creating accounts and providing user information (e.g., contact information, or a home or office address) to the network system  100 . The network system  100  stores the user information in the user data store  210 . The network system  100  can associate feedback received from a user or data from trips (e.g., pickup or destination locations, signatures of short-range transmission detected by a client device  110  as a user navigates to a pickup location, or other sensor data) taken by the user with the registered account of the user. 
     The map data store  205  stores map information of geographic regions in which the network system  100  offers services such as transportation for users. The map information may include map properties of a geographical region such as road properties that describe characteristics of the road segments, such as speed limits, road directionality (e.g., one-way or two-way), traffic history, traffic conditions, addresses on the road segment, length of the road segment, and type of the road segment (e.g., surface street, residential, highway, toll). Moreover, the map information may include map properties of venues and buildings such as floor plans (or layout) of a shopping mall, airport, business complex, fairgrounds, etc. The floor plans may indicate the location of stairs, escalators, or elevators, bathrooms, exits/entrances, points of interest, commercial or residential addresses and related information (e.g., name, type, multimedia, or hours of operation of a shopping mall), loading zones at a curb, and the like. The network system  100  may use the map data store  205  to determine navigation information, pickup locations, or destination locations for users. 
     The matching engine  200  coordinates services provided by the providers to users. In particular, the matching engine  200  selects providers to service the requests of users. For example, the matching engine  200  receives a trip request from a user and determines a set of candidate providers that are online, open (e.g., are available to transport a user), and near the requested pickup location for the user. The matching engine  200  selects a provider from the set of candidate providers to which it transmits an assignment request. Specifically, the matching engine  200  may select a provider based on, e.g., a signature of short-range transmission, the provider&#39;s location, the pickup or destination location, the type of the provider, the amount of time the provider has been waiting for an assignment request, among other factors. 
     The navigation engine  220  provides navigation information for users to travel to pickup locations, in response to receiving requests for service from the users. A client device  110  of a user may present the navigation information as routing instructions using graphical elements (e.g., an arrow or highlighted path on a map), text (e.g., “walk toward the elevators,” “take the stairs to the ground floor,” or “head toward the lobby”), audio instructions, any combination thereof, or other suitable methods to convey the routing instructions. Additionally, the client device  110  may detect one or more signatures of short-range transmission as the user navigates from a current location to a pickup location. The client device  110  provides the detected signatures of short-range transmission to the network system  100 , which stores the detected signatures as reference signatures in the signature data store  225 . In particular, the navigation engine  220  may associate a reference signature with a corresponding location of a floor plan of a building (e.g., from the map data store  205 ). For instance, a reference signature is detected by a client device  110  when the user navigated to (and was located at) the elevators of the building. Thus, the navigation engine  220  may map the reference signature to the given location of the elevators, e.g., by tagging the reference signature with the given location or storing the data in a look-up table (LUT). 
     In some embodiments, the network system  100  tasks a user or provider (not necessarily requesting a service) to navigate around a geographical region, such as a building or venue, to collect reference signatures detected by a client device  110  at various locations within or nearby the geographical region. In contrast to passively detecting signatures by client devices  110  of users requesting services (as described above), tasking users or providers is a more active method for the network system  100  to generate or update a map of reference signatures for the geographical region. The navigation engine  220  may aggregate reference signatures received from both the passive and active methods in the signature data store  225 . Further, the navigation engine  220  may periodically update reference signatures in the signature data store  225  to account for changes of a geographical region over time, e.g., previous broadcasters  120  are removed or re-located, new broadcasters  120  are added, or a portion of a building undergoes construction/remodeling. 
     The navigation engine  220  determines navigation information by analyzing signatures short-range transmission using the signal processing engine  230 . In particular, responsive to the network system  100  receiving a request for service from a client device  110  of a given user, the signal processing engine  230  receives a signature detected by the client device  110 . The signal processing engine  230  checks for similarities between the signature and reference signatures of the signature data store  225 . Responsive to determining that a level of similarity between the signature and a given reference signature is greater than a threshold value, the signal processing engine  230  identifies a location associated with the given reference signature in the signature data store  235 . The navigation engine  220  determines that the identified location is the current location of the client device  110 . Using map information from the map data store  205 , the navigation engine  220  determines a route for travel for the user from the current location to the pickup location. Further, the navigation engine  220  may store the route for travel, or an actual route traveled by the client device  110  (e.g., if the user took a detour or otherwise deviated from the route) in the user data store  210 . 
     In an embodiment, the navigation engine  220  determines “hotspot locations” that were previously selected a threshold number of times for services provided via the network system  100  (e.g., popular pickup locations selected by other users). For example, the hotspot locations (e.g., stored in the map data store  205 ) are located at or nearby transit stations, entrances/exits of buildings, or other points-of-interest such as tourist attractions or public spaces. The navigation engine  220  may determine to use one of the hotspot locations as the pickup location and determine the route for travel by the user based on the hotspot location. For instance, the navigation engine  220  receives a point address input by the user using the client device  110 . The navigation engine  220  performs lookups from the map data store  205  to identify a hotspot that is located within a threshold distance from the point address. Thus, the navigation engine  220  may predict that the user intended to select the identified hotspot location, but inputted the point address instead as an approximate location, e.g., because the user did not know the exact address of the hotspot location. In some embodiments, the navigation engine  220  may retrieve, from the user data store  210 , previous routes provided to other users or traveled by other users to hotspot locations (e.g., used as pickup locations) for services provided via the network system  100 . The navigation engine  220  may determine a route for travel by the user to the hotspot location based on the previous routes. For instance, by aggregating the previously traveled routes, the navigation engine  220  may optimize for duration of travel time when determining the route from a current location of the user to the hotspot location, e.g., determining to travel through one section of a mall that is less crowded on average than another section of the mall. 
     In some embodiments, the signal processing engine  230  processes telematics data captured by sensors of client devices  110  to determine commute information describing navigation of client devices  110  to pickup locations. For example, the telematics data indicates a speed at which the client device  110  is moving. Thus, the signal processing engine  230  can determine whether a user of the client device  110  is walking or on a vehicle, e.g., moving faster on average than an estimated walking speed. The signal processing engine  230  may store the commute information, telematics data, and/or associated information (e.g., which may be mapped to a request for service) in the signature data store  235 . Additionally, the signal processing engine  230  may use the commute information to determine a current location of a client device  110 , and the navigation engine  220  may determine navigation information further using the commute information. The navigation engine  220  and the signal processing engine  230  are further described below in the example described with reference to  FIGS. 3-4 . 
     III. Example Broadcasters and Signatures of Short-Range Transmissions 
       FIG. 3  is a diagram of broadcasters in a building  300  according to one embodiment. For example, the building  300  shown in  FIG. 3  is a mall (e.g., a multi-floor shopping mall) that includes broadcasters  120  transmitting short-range transmissions. In the embodiment shown in  FIG. 3 , broadcasters  120 A and  120 B are Wi-Fi transmitters positioned at the third and first floors of the mall, respectively. The first floor may be a ground floor, e.g., with entrances/exits to a curb or road for pickup by a vehicle. In other embodiments, there may be pickup locations available on a different floor or multiple floors, including underground floors. The map data store  205  of the network system  100  includes reference signatures (e.g., of detected short-range transmissions from broadcasters  120 A and  120 B) previously collected from various locations within the mall.  FIG. 4  is a set of diagrams showing signatures of short-range transmissions detected from the broadcasters  120 A and  120 B shown in  FIG. 3  according to one embodiment. 
     In an example use case, the network system  100  receives a request for service from a client device  110  of a user at an initially unknown location. Additionally, the navigation engine  220  determines that the user wants to start the service at “pickup location A” on the south side of the mall. The client device  110  detects and provides a first signature of short-range transmission to the network system  100 . Graph  410  in  FIG. 4  illustrates a “reference signature A” previously detected by another client device at location A. The amplitude, frequency, or other characteristics of the reference signature A may be based on the short-range transmissions emitted by the broadcaster  120 A located nearby on the third floor. By performing a lookup in the signature data store  225 , the signal processing engine  230  determines that a level of similarity between the first signature and the reference signature A is less than a threshold value. For instance, the signal processing engine  230  compares the amplitude or frequency of the first signature and the reference signature A to determine the level of similarity. Other similarity criterion may be based on, e.g., a detected Wi-Fi network name (SSID), received signal strength indicator (RSSI), Basic Service Set Identifier (BSSID) based on a media access control (MAC) address of an access point, an average frequency of the signatures, or a frequency response of the signatures. In some embodiments, the signal processing engine  230  uses machine learning techniques to refine criterion for determining levels of similarity. Responsive to determining that the level of similarity between the first signature and the reference signature A is less than the threshold value, the navigation engine  220  determines that the client device  110 , and the user by extension, is located at location A. 
     The navigation engine  220  determines a route for the user to travel from location A to the pickup location A. In some embodiments, the navigation engine  220  determines a route having one or more intermediate locations, e.g., to serve as checkpoints to track whether the user is correctly following the provided route. In the example shown in  FIG. 3 , the dotted arrow lines indicate the route and route directionality. Further, the route includes two intermediate locations, “location B” on the second floor and “location C” on the first floor. When the user is at location A, the navigation engine  220  provides navigation information to the client device  110  to present routing instructions for the user to travel to location B by taking the escalator down from the third floor. The routing instructions may also indicate other information describing location B to assist the user in finding location B, e.g., “walk toward the north side of the mall until you reach the escalators,” or “you should pass by a café along the way.” As the user travels from location A to location B, the client device  110  may periodically (e.g., once every few seconds or minutes) detect and provide additional signatures to the network system  100 . Moreover, the signal processing engine  230  continues to search the signature data store  225  for a match to the additional signatures. Responsive to the signal processing engine  230  determining that a level of similarity between one of the additional signatures and the reference signature B (as illustrated in graph  420  in  FIG. 4 ) is less than a threshold value, the navigation engine  220  determines that the client device  110  and user are located at location B on the second floor. 
     After the navigation engine  220  determines that the client device  110  is at location B, the navigation engine  220  provides additional navigation information, for the next part of the route, to the client device  110 . The client device  110  presents updated routing instructions for the user to travel from location B to pickup location A, e.g., by taking the escalator down to the first floor and walking out of an exit on the south side of the mall. As the user travels from location B, the client device  110  continues to periodically detect and provide signatures to the network system  100 . The signal processing engine  230  may determine that another detected signature matches reference signature C (as illustrated in graph  430  in  FIG. 4 ). Responsive to this determination, the navigation engine  220  determines that the user is again correctly following the provided route to pickup location A. Additionally, the navigation engine  220  may provide navigation information to the client device  110  indicating that the user has arrived at the pickup location A, responsive to determining a match with a reference signature associated with pickup location A (not shown in  FIG. 4 ). 
     In some situations, the user may take a wrong turn or detour from the provided route. For instance, the user became confused as to which side of the mall is south. Consequently, the user instead walks toward pickup location B on the north side of the mall. In this case, the signal processing engine  230  does not determine that any signature detected as the user travels from location B to pickup location B matches reference signature C. After waiting a threshold duration of time (e.g., a timeout) without a match to reference signature C, the navigation engine  220  determines that the user arrived at a deviated location and may provide an indication that the client device  110  has deviated from the provided route. The client device  110  may present the indication to the user as well as routing instructions to return to the correct direction, e.g., “turn back and go to the opposite side of the mall.” 
     In the above example described with respect to  FIGS. 3-4 , broadcasters  120 A and  120 B transmit short-range transmissions having different frequencies. Thus, the reference signatures A and B shown in graphs  410  and  420  have a first frequency, while the reference signature C shown in graph  430  has a second frequency, which is greater than the first frequency. Further, the strength of a detected short-range transmission may decrease as a client device  110  is located further from the originating broadcaster  120 . Accordingly, the peak-to-peak amplitude of the reference signature shown in graph  420  is less than that of the reference signature shown in graph  410  because location B is further away (and separated by a floor of the building) from broadcaster  120 A than is location A, as shown in  FIG. 3 . Based on these variations in frequency and amplitude, the signal processing engine  230  may determine levels of similarity between detected signatures and reference signatures with sufficient granularity to determine locations of the client device  110  within different floors and sections of the mall. 
     In some embodiments, the navigation engine  220  and signal processing engine  230  determine navigation information without needing to use GPS data from client devices  110 . In other embodiments, the navigation engine  220  and signal processing engine  230  may use both GPS data and signatures of short-range transmission to determine navigation information. For example, the signal processing engine  230  uses a latitude and longitude of a client device  110  determined based on GPS data to verify matches between detected signatures and reference signatures. In particular, the signal processing engine  230  may use the GPS data to determine a confidence score for signature matches, or may adjust a threshold value for comparing a level of similarity between a detected signature and a reference signature. 
     It should be noted that the graphs shown in  FIG. 4  are for illustrative purposes. That is, client devices  110  and the network system  100  do not necessarily graph detected signatures or reference signatures of short-range transmission. Further, the graphs of  FIG. 4  show reference signatures each originating from one broadcaster  120 , though in practice, client devices may simultaneously detect short-range transmissions from multiple broadcasters  120 . Thus, in some embodiments, the detected signature is a superposition of multiple short-range transmissions, each of which may have different parameters (e.g., frequency, amplitude, or SSID). The signal processing engine  230  may filter out noise from detected signatures based on one or more parameters, such as an pre-determined list of target SSIDs of Wi-Fi signals, e.g., based on known information about broadcasters  120  in a venue or building retrieved from the map data store  205 . 
     IV. Example Process Flow 
       FIG. 5  is a flowchart illustrating a process for determining a route to a pickup location according to one embodiment. In some embodiments, the network system  100  uses the process  500  within the system environment in  FIG. 1 . The process  500  may include different or additional steps than those described in conjunction with  FIG. 5  in some embodiments or perform steps in different orders than the order described in conjunction with  FIG. 5 . 
     In one embodiment, the signal processing engine  230  retrieves  510  a signature of short-range transmission detected by a particular client device  110  of a particular user of the network system  100 . The signal processing engine  230  determines  520 , using one or more processors, a current location of the particular client device  110  by comparing the retrieved signature to reference signatures of short-range transmissions received from client devices of a plurality of users of the network system  100  (stored in the signature data store  225 ), where each reference signature associated with a location (e.g., a store or floor within a mall building). The navigation engine  220  determines  530 , using the one or more processors, a route for travel by the particular user from the current location to a pickup location via an intermediate location for a start of a service provided via the network system  100 . At least one of the reference signatures stored in the signature data store  225  is associated with the intermediate location. The navigation engine  220  provides  540  at least part of the route to the particular client device  120  for presentation to the particular user. 
     In some embodiments, the signal processing engine  230  receives a subsequent signature of short-range transmission detected by the particular client device  110  after providing the at least part of the route to the particular client device  110  for presentation. Responsive to determining that the particular user arrived at the intermediate location by comparing the subsequent signature to the reference signature associated with the intermediate location, the navigation engine  220  may provide an updated part of the route to the particular client device  110  for presentation to the particular user. The signal processing engine  230  may determine that the particular user arrived at the intermediate location responsive to determining that the particular client device  110  is located within threshold distance from the intermediate location based on the comparison. 
     In some embodiments, the signal processing engine  230  may also analyze signatures of short-range transmission detected by another client device  110  of a provider. In an example use case, the provider is a driver selected by the matching engine  200  to provide transportation service to the user starting at a determined pickup location. Responsive to the signal processing engine  230  determining a match between a signature detected by the provider&#39;s client device  110  and a reference signature associated with the pickup location (e.g., pickup location A shown in  FIG. 3 ), the navigation engine  220  may provide navigation information to the providers&#39; client device  110 . Based on the navigation information, the client device  110  presents an indication that the driver has arrived at the determined pickup location and should rendezvous shortly with the user to begin the transportation service. 
     V. Example Physical Components of a Computer 
       FIG. 6  is a high-level block diagram illustrating physical components of a computer  600  used as part or all of the components from  FIG. 1  (e.g., the network system  100  or client devices  110 ), according to one embodiment. Illustrated are at least one processor  602  coupled to a chipset  604 . Also coupled to the chipset  604  are a memory  606 , a storage device  608 , a graphics adapter  612 , and a network adapter  616 . A display  618  is coupled to the graphics adapter  612 . In one embodiment, the functionality of the chipset  604  is provided by a memory controller hub  620  and an I/O controller hub  622 . In another embodiment, the memory  606  is coupled directly to the processor  602  instead of the chipset  604 . 
     The storage device  608  is any non-transitory computer-readable storage medium, such as a hard drive, compact disk read-only memory (CD-ROM), DVD, or a solid-state memory device. The memory  606  holds instructions and data used by the processor  602 . The graphics adapter  612  displays images and other information on the display  618 . The network adapter  616  couples the computer  600  to a local or wide area network. 
     As is known in the art, a computer  600  can have different and/or other components than those shown in  FIG. 6 . In addition, the computer  600  can lack certain illustrated components. In one embodiment, a computer  600  such as a server or smartphone may lack a graphics adapter  612 , and/or display  618 , as well as a keyboard or pointing device. Moreover, the storage device  608  can be local and/or remote from the computer  600 , e.g., embodied within a storage area network (SAN). 
     As is known in the art, the computer  600  is adapted to execute computer program modules or engines for providing functionality described herein. As used herein, the terms “module” or “engine” refer to computer program logic utilized to provide the specified functionality. Thus, a module and/or engine can be implemented in hardware, firmware, and/or software. In one embodiment, program modules and/or engines are stored on the storage device  608 , loaded into the memory  606 , and executed by the processor  602 . 
     VI. Additional Configurations 
     The foregoing description of the embodiments of the invention has been presented for the purpose of illustration; it is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Persons skilled in the relevant art can appreciate that many modifications and variations are possible in light of the above disclosure. 
     Some portions of this description describe the embodiments of the invention in terms of algorithms and symbolic representations of operations on information. These algorithmic descriptions and representations are commonly used by those skilled in the data processing arts to convey the substance of their work effectively to others skilled in the art. These operations, while described functionally, computationally, or logically, are understood to be implemented by computer programs or equivalent electrical circuits, microcode, or the like. Furthermore, it has also proven convenient at times, to refer to these arrangements of operations as modules, without loss of generality. The described operations and their associated modules may be embodied in software, firmware, hardware, or any combinations thereof. 
     Any of the steps, operations, or processes described herein may be performed or implemented with one or more hardware or software modules, alone or in combination with other devices. In one embodiment, a software module is implemented with a computer program product including a computer-readable non-transitory medium containing computer program code, which can be executed by a computer processor for performing any or all of the steps, operations, or processes described. 
     Embodiments of the invention may also relate to a product that is produced by a computing process described herein. Such a product may include information resulting from a computing process, where the information is stored on a non-transitory, tangible computer readable storage medium and may include any embodiment of a computer program product or other data combination described herein. 
     Finally, the language used in the specification has been principally selected for readability and instructional purposes, and it may not have been selected to delineate or circumscribe the inventive subject matter. It is therefore intended that the scope of the invention be limited not by this detailed description, but rather by any claims that issue on an application based hereon. Accordingly, the disclosure of the embodiments of the invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims.