Patent Publication Number: US-8989763-B2

Title: Updating position assist data on a mobile computing device

Description:
RELATED APPLICATION DATA 
     The present application is related to U.S. patent application Ser. No. 11/729,966 titled “UPDATING POSITION ASSIST DATA ON A MOBILE COMPUTING DEVICE,” and filed Mar. 29, 2007, the disclosure of which is hereby incorporated by reference in its entirety. 
     BACKGROUND 
     Some mobile computing devices provide location-based services to a user. For example, a user may use a mobile computing device to report their location to a 9-1-1 emergency service in the event of an emergency. Further, the mobile computing device may use a navigation application to provide directions from the user&#39;s current location to a desired destination. 
     A mobile computing device uses various types of position assist data to assist in the calculation of position fixes for use with the location-based services. Position assist data includes almanac, ephemeris, and coarse data, and may also include mobile-station assist data such as visible satellite data and Doppler data. Almanac data may require updating every 6 months. Ephemeris data may require updating every 30 to 90 minutes, and may need to be updated even more frequently (e.g., every minute or less) if the device is moving, since ephemeris data provides data about the orbital information specific to the satellites within visibility at a particular position. Coarse data may provide a last known position and time to a calculation algorithm to speed up calculation of a subsequent position fix. 
     If the position assist data is not up-to-date or “fresh,” then the device may need to update one or more types of position assist data before it responds to the request for a position fix. Updating position assist data takes time and power, and may take wireless bandwidth. Position assist data may be updated using signals from global positioning system (GPS) satellites, though current approaches take substantial time to download the data. 
     Accordingly, there is a need for a system and method for maintaining or updating position assist data. Further, there is a need for updating position assist data with reduced time, power and/or wireless bandwidth. Further, there is a need for updating position assist data less often depending on various states of the device and data stored on the device. Further still, there is a need for updating position assist data while minimizing a user&#39;s perception of the update. Further still, there is a need for using a wireless network to receive position assist data, which may receive the position assist data faster than other methods and which may provide useful position data. Further still, there is a need for updating position assist data while minimizing the use of network airtime. Further still, there is a need for updating position assist data while minimizing disruptions of other processes or applications running on the device. Further still, there is a need for minimizing or eliminating the need for updates of position assist data made at the time of receiving a position fix request (i.e., “ad hoc” updates). Further still, there is a need for minimizing instances of moving one or more components of a mobile computing device out of a sleep mode. 
     The teachings herein extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the above-mentioned needs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a mobile computing device, according to an exemplary embodiment; 
         FIG. 2  is a back view of a mobile computing device, according to an exemplary embodiment; 
         FIG. 3  is a block diagram of the mobile computing device of  FIGS. 1 and 2 , according to an exemplary embodiment; 
         FIG. 4  is a flowchart illustrating a system and method for updating position assist data, according to an exemplary embodiment; 
         FIG. 5  is a flowchart illustrating a system and method for updating position assist data, according to an exemplary embodiment; 
         FIG. 6  is a flowchart illustrating a system and method for updating position assist data, according to an exemplary embodiment; 
         FIG. 7  is a flowchart illustrating a system and method for updating position assist data, according to an exemplary embodiment; 
         FIG. 8  is a flowchart illustrating a system and method for updating position assist data, according to an exemplary embodiment; 
         FIG. 9  is a flowchart illustrating a system and method for updating position assist data, according to an exemplary embodiment; and 
         FIG. 10  is a flowchart illustrating a system and method for updating position assist data, according to an exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The disclosure of U.S. patent application Ser. No. 11/469,374 filed Aug. 31, 2006 is incorporated by reference herein in its entirety. 
     Referring first to  FIG. 1 , a mobile computing device  100  is shown. Device  100  is a smart phone, which is a combination mobile telephone and handheld computer having personal digital assistant functionality. The teachings herein can be applied to other mobile computing devices (e.g., a laptop computer) or other electronic devices (e.g., a desktop personal computer, etc.). Personal digital assistant functionality can comprise one or more of personal information management, database functions, word processing, spreadsheets, voice memo recording, etc. and is configured to synchronize personal information from one or more applications with a computer (e.g., desktop, laptop, server, etc.). Device  100  is further configured to receive and operate additional applications provided to device  100  after manufacture, e.g., via wired or wireless download, Secure Digital card, etc. 
     Device  100  comprises a housing  11  having a front side  13  and a back side  17  ( FIG. 2 ). An earpiece speaker  15  may be an electro-acoustic transducer configured to provide audio output with a volume suitable for a user placing earpiece  15  against or near the ear. Loudspeaker  16  may be an electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance. Loudspeaker  16  can be used for a speakerphone functionality. In alternative embodiments, display  112 , user input device  110 , earpiece  15  and loudspeaker  16  may each be positioned anywhere on front side  13 , back side  17  or the edges there between. 
     Device  100  may provide voice communications functionality in accordance with different types of cellular radiotelephone systems. Examples of cellular radiotelephone systems may include Code Division Multiple Access (CDMA) cellular radiotelephone communication systems, Global System for Mobile Communications (GSM) cellular radiotelephone systems, etc. 
     In addition to voice communications functionality, device  100  may be configured to provide data communications functionality in accordance with different types of cellular radiotelephone systems. Examples of cellular radiotelephone systems offering data communications services may include GSM with General Packet Radio Service (GPRS) systems (GSM/GPRS), CDMA/1xRTT systems, Enhanced Data Rates for Global Evolution (EDGE) systems, Evolution Data Only or Evolution Data Optimized (EV-DO) systems, etc. 
     Device  100  may be configured to provide voice and/or data communications functionality in accordance with different types of wireless network systems. Examples of wireless network systems may further include a wireless local area network (WLAN) system, wireless metropolitan area network (WMAN) system, wireless wide area network (WWAN) system, and so forth. Examples of suitable wireless network systems offering data communication services may include the Institute of Electrical and Electronics Engineers (IEEE) 802.xx series of protocols, such as the IEEE 802.11 a/b/g/n series of standard protocols and variants (also referred to as “WiFi”), the IEEE 802.16 series of standard protocols and variants (also referred to as “WiMAX”), the IEEE 802.20 series of standard protocols and variants, and so forth. 
     Device  100  may be configured to perform data communications in accordance with different types of shorter range wireless systems, such as a wireless personal area network (PAN) system. One example of a suitable wireless PAN system offering data communication services may include a Bluetooth system operating in accordance with the Bluetooth Special Interest Group (SIG) series of protocols, including Bluetooth Specification versions v1.0, v1.1, v1.2, v2.0, v2.0 with Enhanced Data Rate (EDR), as well as one or more Bluetooth Profiles, and so forth. 
     As shown in the embodiment of  FIG. 3 , device  100  may comprise a dual processor architecture including a host processor  102  and a radio processor  104  (e.g., a base band processor). The host processor  102  and the radio processor  104  may be configured to communicate with each other using interfaces  106  such as one or more universal serial bus (USB) interfaces, micro-USB interfaces, universal asynchronous receiver-transmitter (UART) interfaces, general purpose input/output (GPIO) interfaces, control/status lines, control/data lines, shared memory, and so forth. 
     The host processor  102  may be responsible for executing various software programs such as application programs and system programs to provide computing and processing operations for device  100 . The radio processor  104  may be responsible for performing various voice and data communications operations for device  100  such as transmitting and receiving voice and data information over one or more wireless communications channels. Although embodiments of the dual processor architecture may be described as comprising the host processor  102  and the radio processor  104  for purposes of illustration, the dual processor architecture of device  100  may comprise additional processors, may be implemented as a dual- or multi-core chip with both host processor  102  and radio processor  104  on a single chip, etc. 
     In various embodiments, the host processor  102  may be implemented as a host central processing unit (CPU) using any suitable processor or logic device, such as a general purpose processor. The host processor  102  may comprise, or be implemented as, a chip multiprocessor (CMP), dedicated processor, embedded processor, media processor, input/output (I/O) processor, co-processor, a field programmable gate array (FPGA), a programmable logic device (PLD), or other processing device in alternative embodiments. In an exemplary embodiment, host processor  102  is an OMAP2, such as an OMAP2431 processor, manufactured by Texas Instruments, Inc. 
     The host processor  102  may be configured to provide processing or computing resources to device  100 . For example, the host processor  102  may be responsible for executing various software programs such as application programs and system programs to provide computing and processing operations for device  100 . Examples of application programs may include, for example, a telephone application, voicemail application, e-mail application, instant message (IM) application, short message service (SMS) application, multimedia message service (MMS) application, web browser application, personal information manager (PIM) application, contact management application, calendar application, scheduling application, task management application, word processing application, spreadsheet application, database application, video player application, audio player application, multimedia player application, digital camera application, video camera application, media management application, a gaming application, and so forth. The application software may provide a graphical user interface (GUI) to communicate information between device  100  and a user. 
     System programs assist in the running of a computer system. System programs may be directly responsible for controlling, integrating, and managing the individual hardware components of the computer system. Examples of system programs may include, for example, an operating system (OS), device drivers, programming tools, utility programs, software libraries, an application programming interface (API), graphical user interface (GUI), and so forth. Device  100  may utilize any suitable OS in accordance with the described embodiments such as a Palm OS®, Palm OS® Cobalt, Microsoft® Windows OS, Microsoft Windows® CE, Microsoft Pocket PC, Microsoft Mobile, Symbian OS™, Embedix OS, Linux, Binary Run-time Environment for Wireless (BREW) OS, JavaOS, a Wireless Application Protocol (WAP) OS, and so forth. 
     Device  100  may comprise a memory  108  coupled to the host processor  102 . In various embodiments, the memory  108  may be configured to store one or more software programs to be executed by the host processor  102 . The memory  108  may be implemented using any machine-readable or computer-readable media capable of storing data such as volatile memory or non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re-writeable memory, and so forth. Examples of machine-readable storage media may include, without limitation, random-access memory (RAM), dynamic RAM (DRAM), Double-Data-Rate DRAM (DDRAM), synchronous DRAM (SDRAM), static RAM (SRAM), read-only memory (ROM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory (e.g., NOR or NAND flash memory), or any other type of media suitable for storing information. 
     Although the memory  108  may be shown as being separate from the host processor  102  for purposes of illustration, in various embodiments some portion or the entire memory  108  may be included on the same integrated circuit as the host processor  102 . Alternatively, some portion or the entire memory  108  may be disposed on an integrated circuit or other medium (e.g., hard disk drive) external to the integrated circuit of host processor  102 . In various embodiments, device  100  may comprise an expansion slot to support a multimedia and/or memory card, for example. 
     Device  100  may comprise a user input device  110  coupled to the host processor  102 . The user input device  110  may comprise, for example, a QWERTY key layout and an integrated number dial pad. Device  100  also may comprise various keys, buttons, and switches such as, for example, input keys, preset and programmable hot keys, left and right action buttons, a navigation button such as a multidirectional navigation button, phone/send and power/end buttons, preset and programmable shortcut buttons, a volume rocker switch, a ringer on/off switch having a vibrate mode, a keypad, an alphanumeric keypad, and so forth. 
     The host processor  102  may be coupled to a display  112 . The display  112  may comprise any suitable visual interface for displaying content to a user of device  100 . For example, the display  112  may be implemented by a liquid crystal display (LCD) such as a touch-sensitive color (e.g., 16-bit color) thin-film transistor (TFT) LCD screen. In some embodiments, the touch-sensitive LCD may be used with a stylus and/or a handwriting recognizer program. 
     Device  100  may comprise an input/output (I/O) interface  114  coupled to the host processor  102 . The I/O interface  114  may comprise one or more I/O devices such as a serial connection port, an infrared port, integrated Bluetooth® wireless capability, and/or integrated 802.11x (WiFi) wireless capability, to enable wired (e.g., USB cable) and/or wireless connection to a local computer system, such as a local personal computer (PC). In various implementations, device  100  may be configured to transfer and/or synchronize information with the local computer system. 
     The host processor  102  may be coupled to various audio/video (A/V) devices  116  that support A/V capability of device  100 . Examples of A/V devices  116  may include, for example, a microphone, one or more speakers, an audio port to connect an audio headset, an audio coder/decoder (codec), an audio player, a digital camera, a video camera, a video codec, a video player, and so forth. 
     The host processor  102  may be coupled to a power supply  118  configured to supply and manage power to the elements of device  100 . In various embodiments, the power supply  118  may be implemented by a rechargeable battery, such as a removable and rechargeable lithium ion battery to provide direct current (DC) power, and/or an alternating current (AC) adapter to draw power from a standard AC main power supply. 
     As mentioned above, the radio processor  104  may perform voice and/or data communication operations for device  100 . For example, the radio processor  104  may be configured to communicate voice information and/or data information over one or more assigned frequency bands of a wireless communication channel. In various embodiments, the radio processor  104  may be implemented as a communications processor using any suitable processor or logic device, such as a modem processor or base band processor. Although some embodiments may be described with the radio processor  104  implemented as a modem processor or base band processor by way of example, it may be appreciated that the embodiments are not limited in this context. For example, the radio processor  104  may comprise, or be implemented as, a digital signal processor (DSP), media access control (MAC) processor, or any other type of communications processor in accordance with the described embodiments. Radio processor  104  may be any of a plurality of modems manufactured by Qualcomm, Inc. or other manufacturers. 
     In various embodiments, the radio processor  104  may perform analog and/or digital base band operations for device  100 . For example, the radio processor  104  may perform digital-to-analog conversion (DAC), analog-to-digital conversion (ADC), modulation, demodulation, encoding, decoding, encryption, decryption, and so forth. 
     Device  100  may comprise a transceiver module  120  coupled to the radio processor  104 . The transceiver module  120  may comprise one or more transceivers configured to communicate using different types of protocols, communication ranges, operating power requirements, RF sub-bands, information types (e.g., voice or data), use scenarios, applications, and so forth. In various embodiments, the transceiver module  120  may comprise one or more transceivers configured to support voice communication for a cellular radiotelephone system such as a GSM, UMTS, and/or CDMA system. The transceiver module  120  also may comprise one or more transceivers configured to perform data communications in accordance with one or more wireless communications protocols such as WWAN protocols (e.g., GSM/GPRS protocols, CDMA/1xRTT protocols, EDGE protocols, EV-DO protocols, EV-DV protocols, HSDPA protocols, etc.), WLAN protocols (e.g., IEEE 802.11a/b/g/n, IEEE 802.16, IEEE 802.20, etc.), PAN protocols, Infrared protocols, Bluetooth protocols, EMI protocols including passive or active RFID protocols, and so forth. 
     The transceiver module  120  may be implemented using one or more chips as desired for a given implementation. Although the transceiver module  120  may be shown as being separate from and external to the radio processor  104  for purposes of illustration, in various embodiments some portion or the entire transceiver module  120  may be included on the same integrated circuit as the radio processor  104 . 
     Device  100  may comprise an antenna system  122  for transmitting and/or receiving electrical signals. As shown, the antenna system  122  may be coupled to the radio processor  104  through the transceiver module  120 . The antenna system  122  may comprise or be implemented as one or more internal antennas and/or external antennas. 
     Device  100  may comprise a memory  124  coupled to the radio processor  104 . The memory  124  may be implemented using one or more types of machine-readable or computer-readable media capable of storing data such as volatile memory or non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re-writeable memory, etc. The memory  124  may comprise, for example, flash memory and secure digital (SD) RAM. Although the memory  124  may be shown as being separate from and external to the radio processor  104  for purposes of illustration, in various embodiments some portion or the entire memory  124  may be included on the same integrated circuit as the radio processor  104 . 
     Device  100  may comprise a subscriber identity module (SIM)  126  coupled to the radio processor  104 . The SIM  126  may comprise, for example, a removable or non-removable smart card configured to encrypt voice and data transmissions and to store user-specific data for allowing a voice or data communications network to identify and authenticate the user. The SIM  126  also may store data such as personal settings specific to the user. 
     Device  100  may comprise an I/O interface  128  coupled to the radio processor  104 . The I/O interface  128  may comprise one or more I/O devices to enable wired (e.g., serial, cable, etc.) and/or wireless (e.g., WiFi, short range, etc.) communication between device  100  and one or more external computer systems. 
     In various embodiments, device  100  may comprise location or position determination capabilities. Device  100  may employ one or more location determination techniques including, for example, Global Positioning System (GPS) techniques, Cell Global Identity (CGI) techniques, CGI including timing advance (TA) techniques, Enhanced Forward Link Trilateration (EFLT) techniques, Time Difference of Arrival (TDOA) techniques, Angle of Arrival (AOA) techniques, Advanced Forward Link Trilateration (AFTL) techniques, Observed Time Difference of Arrival (OTDOA), Enhanced Observed Time Difference (EOTD) techniques, Assisted GPS (AGPS) techniques, hybrid techniques (e.g., GPS/CGI, AGPS/CGI, GPS/AFTL or AGPS/AFTL for CDMA networks, GPS/EOTD or AGPS/EOTD for GSM/GPRS networks, GPS/OTDOA or AGPS/OTDOA for UMTS networks), etc. 
     Device  100  may be configured to operate in one or more location determination modes including, for example, a standalone mode, a mobile station (MS) assisted mode, and/or a MS-based mode. In a standalone mode, such as a standalone GPS mode, device  100  may be configured to determine its position without receiving wireless navigation data from the network, though it may receive certain types of position assist data, such as almanac, ephemeris, and coarse data. In a standalone mode, device  100  may comprise a local location determination circuit  134  (e.g., a GPS receiver) which may be integrated within housing  11  ( FIG. 1 ) configured to receive satellite data via an antenna  135  and to calculate a position fix. Local location determination circuit may alternatively comprise a GPS receiver in a second housing separate from housing  11  but in the vicinity of device  100  and configured to communicate with device  100  wirelessly (e.g., via a PAN, such as Bluetooth). When operating in an MS-assisted mode or an MS-based mode, however, device  100  may be configured to communicate over a radio access network  130  (e.g., UMTS radio access network) with a remote computer  132  (e.g., a location determination entity (PDE), a location proxy server (LPS) and/or a mobile positioning center (MPC), etc.). 
     In an MS-assisted mode, such as an MS-assisted AGPS mode, the remote computer  132  may be configured to determine the position of the mobile computing device and provide wireless data comprising a position fix. In an MS-based mode, such as an MS-based AGPS mode, device  100  may be configured to determine its position using acquisition data or other wireless data from the remote computer  132 . The acquisition data may be provided periodically. In various implementations, device  100  and the remote computer  132  may be configured to communicate according to a suitable MS-PDE protocol (e.g., MS-LPS or MS-MPC protocol) such as the TIA/EIA standard IS- 801  message protocol for MS-assisted and MS-based sessions in a CDMA radiotelephone system. 
     When assisting the mobile computing device  100 , the remote computer  132  may handle various processing operations and also may provide information to aid location determination. Examples of position assist data may include satellite-based measurements, terrestrial-based measurements, and/or system-based measurements such as satellite almanac information, GPS code phase measurements, ionospheric data, ephemeris data, time correction information, altitude estimates, timing offsets, forward/reverse link calibration, coarse data, and so forth. 
     In various implementations, the position assist data provided by the remote computer  132  may improve the speed of satellite acquisition and the probability of a position fix by concentrating the search for a GPS signal and/or may improve the accuracy of location determination. Each position fix or series of position fixes may be available at device  100  and/or at the remote computer  132  depending on the location determination mode. In some cases, data calls may be made and position assist data may be sent to device  100  from the remote computer  132  for every position fix (e.g., in an ad hoc mode). In other cases, data calls may be made and position assist data may be sent periodically and/or as needed. 
     In various embodiments, device  100  may comprise dedicated hardware circuits or structures, or a combination of dedicated hardware and associated software, to support location determination. For example, the transceiver module  120  and the antenna system  122  may comprise GPS receiver or transceiver hardware and one or more associated antennas coupled to the radio processor  104  to support location determination. 
     The host processor  102  may comprise and/or implement at least one LBS (location-based service) application. In general, the LBS application may comprise any type of client application executed by the host processor  102 , such as a GPS application, configured to communicate location requests (e.g., requests for position fixes) and location responses. Examples of LBS applications include, without limitation, wireless 911 emergency services, roadside assistance, asset tracking, fleet management, friends and family locator services, dating services, and navigation services which may provide the user with maps, directions, routing, traffic updates, mass transit schedules, information regarding local points-of-interest (POI) such as restaurants, hotels, landmarks, and entertainment venues, and other types of LBS services in accordance with the described embodiments. 
     The LBS application may be configured to send a location request in response to receiving input from device  100  or from a source external to device  100 . For example, the user of device  100  may interact with a data input device to command the LBS application to send a location request. The LBS application also may send a location request in response to receiving input from an external network element or computing device that is attempting to locate the user of device  100 . In some cases, the LBS application also may be configured to automatically, periodically, and/or autonomously send location requests. 
     Although other applications may operate without regard to the location of device  100 , in various embodiments, the LBS application may request and receive position information to enhance the functionality of one or more of the other applications. For example, position information may be provided in conjunction with a messaging application to locate the sender or recipient of a message. Position information may be provided to a web browser application to generate directions to a location associated with a particular website. Positioning information may be provided to a personal management application to generate location-based alerts and/or directions to a meeting place. 
     The radio processor  104  may be configured to receive location requests from an LBS API handler on host processor  102  and may forward location responses to the LBS API handler for delivery to the LBS application through the LBS API. Radio processor  104  may be configured to communicate securely over a network with remote computer  132  (e.g., PDE, LPS or MPC) configured to provide authentication and authorization services and/or a variety of geo-services. For example, radio processor  104  may be configured to communicate with a PDE configured to verify privacy for location requests, allow authorized access to a location server, and provide various location server services. Radio processor  104  also may be configured to communicate with a PDE to request and receive geo-service information. Examples of geo-service information may include mapping information, routing information, geo-coding and reverse geo-coding information for addresses and coordinates, POI information, and so forth. 
     Radio processor  104  may be configured to invoke a position fix by configuring a position engine and requesting a position fix. For example, a position engine interface on radio processor  104  may set configuration parameters that control the location determination process. Examples of configuration parameters may include, without limitation, location determination mode (e.g., standalone, MS-assisted, MS-based), actual or estimated number of position fixes (e.g., single position fix, series of position fixes, request position assist data without a position fix), time interval between position fixes, Quality of Service (QoS) values, optimization parameters (e.g., optimized for speed, accuracy, or payload), PDE address (e.g., IP address and port number of LPS or MPC), etc. 
     Radio processor  104  also may set request/response parameters to request and return various types of position information. Examples of request/response parameters may include current location, latitude, longitude, altitude, heading, vector information such as horizontal and vertical velocity, sector-based position location, position fix method, level of accuracy, time offset, position uncertainty, device orientation, client initialization and registration, and so forth. 
     The radio processor  104  may comprise or implement a position engine such as a GPS engine. In various embodiments, the position engine may be configured to provide location determination capabilities for device  100 . In some embodiments, the position engine may be implemented as software operating in conjunction with hardware (e.g., GPS receiver hardware) allowing device  100  to receive and process GPS satellites signals for location determination. In one embodiment, the position engine may be implemented as a QUALCOMM® gpsOne® engine. 
     In various implementations, the position engine may employ one or more location determination techniques such as GPS, CGI, CGI+TA, EFLT, TDOA, AOA, AFTL, OTDOA, EOTD, AGPS, GPS/AGPS, hybrid techniques, and so forth. The position engine also may be configured to operate in one or more location determination modes including a standalone mode, an MS-assisted mode, and an MS-based mode. The determined position information generated and/or obtained by the position engine generally may comprise any type of information associated with the location of device  100 . Examples of position information may include, without limitation, current location, latitude, longitude, altitude, heading information, vector information such as horizontal and vertical velocity, sector-based position location, position fix information, position uncertainty, device orientation, and so forth. 
     Referring now to  FIGS. 4-10 , various embodiments of systems and methods for updating position assist data will be described. When device  100  receives a request for a position fix (e.g., from an LBS application, a user, or other requester), device  100  is configured to use the position assist data to calculate the position fix. If one or more of the position assist data are not up-to-date or “fresh,” device  100  may need to update the data before responding to the request. Further, by keeping the coarse data as up-to-date as possible, requests for position fixes can be processed quicker. Device  100  may even be able to respond to a request for a position fix without a new position calculation depending on the freshness of the coarse data and the requirements of the position fix. The coarse data may be accurate enough to satisfy the needs of the request. 
     Almanac and ephemeris data are used by device  100  to assist in acquiring GPS satellite signals. Depending on the circumstances of device  100  at the time of the request for a position fix, the time required to update expired almanac and ephemeris data could be as much as fifteen minutes or more, whereas a delay of over a second or two can result in an undesirable user experience. Accordingly, one or more of the systems and methods described below may be implemented alone or together to keep the almanac, ephemeris, coarse and other position assist data as up to date as possible. 
     Referring to  FIG. 4 , device  100  is configured to determine the likelihood of a need for an update to position assist data. At step  400 , device  100  is configured to store at least one type of position assist data (e.g., almanac, ephemeris, coarse, MS-assist, etc.). At step  402 , device  100  determines whether it is in a first mode or a second mode. If device  100  is in a first mode (mode  1 ), updates of position assist data in an autonomous, or automatic manner, are disabled, as shown in step  406 . A second mode, (mode  2 ) enables updates of position assist data, which may be done automatically, autonomously, periodically, without user input, etc., as shown at step  404 . Step  402  can determine the mode of device with reference to a flag in non-volatile memory or by another mechanism. At step  408 , device  100  determines whether it has been used for a position fix yet (e.g., since manufacture, since a hard reboot, since a soft reboot, etc.) and if it has, and (step  410 ) the position fix has not been due to an emergency position fix (e.g., E-911 service), at step  412  mode  2  is selected to enable updates of position assist data. At step  408 , if device  100  has not been used yet for a position fix, device  100  determines whether applications requiring a position fix have been installed at step  414 . If applications requiring a position fix have been installed, mode  2  is selected at step  412  to enable updates of position assist data. In some embodiments, even if applications requiring a position fix have been installed as determined at step  414 , mode  2  may not be selected based on this criteria if the applications do not meet an additional criteria at step  415 . For example, it may be determined at step  415  whether the installed applications have been used to obtain a position fix within a predetermined or calculated (e.g. based on history of usage of the position fix ability by the applications) amount of time, whether the currently stored position data is capable of providing an accurate enough position fix for the application within a suitable amount of time when requested by the application, etc. 
     If applications requiring a position fix have not been installed at step  414  or meet the criteria at step  415 , other criteria may be checked at step  416 . If the device has not been used for a position fix, and no applications requiring position fix have been installed in this embodiment, device  100  remains in mode  1 , which disables updates of position assist data as shown in step  406 . Alternatively, only one or two of steps  408 ,  410 ,  414 , and  416  may be used to make the determination of whether to enable updates of position assist data. 
     As mentioned, device  100  may store a flag in non-volatile memory or other indication for whether device  100  has been used for a non-emergency position fix and/or whether or not any applications that might request position fixes have been installed on device  100 . Until a flag is set under one of these circumstances, device  100  may remain in mode  1  to disable updates of position assist data, which may disable updates of some or all types of position assist data. In mode  2 , position assist data may be updated in response to any number of different triggering events, such as, the initial determination to enter mode  2 , a user input device, a request for position fix from an application or other user, and/or one or more of a variety of periodic, autonomous, or automatic triggers to update position assist data, such as those described herein below. In some embodiments the triggering event may be the launch of an application that may use position fix information, etc. In some of these embodiments, the position assist data may be updated upon launch of the application even when the application does not request a position fix. 
     The determination of whether an application is of the type to request a position fix could be made by viewing a header file or a library file associated with the application, by having the device  100  or a user of device  100  manually test an application, by viewing a security level or certification data associated with the application (e.g., certified by a wireless carrier to request position fixes), by providing a prompt to a user to have the user select whether a newly-loaded application requires position fixes, by checking a profile associated with the application, by searching one or more data stores which may be local to or remote from (e.g. accessible across a network such as the Internet by) device  100 , and/or by other mechanisms. Device  100  may in an exemplary embodiment only be capable of identifying whether certain types of applications require position fixes, and may, therefore, make the determination of whether to stay in mode  1  only with respect to those applications. In this circumstance, device  100  may await a request for a position fix from an application before entering mode  2 , even though the application is one which requires position fixes, since device  100  is incapable of identifying it as an application requiring position fixes. 
     Applications requiring a position fix may be a navigation application, a child finder application, other LBS applications, or other applications requiring a position fix, whether original equipment software or loaded subsequent to manufacture via a third-party application. 
     In some embodiments, if a triggering event occurred, the position assist data may be updated regularly/periodically (e.g. autonomously) as a response to the initial triggering event. The update may occur at regular intervals, at irregular intervals, at calculated intervals such as calculated intervals that vary based on other criteria, and/or in some other manner, including in the manner described below for updating in response to a request for a position fix. 
     Referring now to  FIG. 5 , device  100  is configured to store at least one type of position assist data at step  500 . At step  502 , a wireless communication call is established which is unrelated to a request for position assist data, such as a telephone call or data communication call for email or other data communications. Device  100  is configured to communicate a request for updated position assist data for one or more of the types of position assist data during the wireless communication call, as shown at step  506 . According to an alternative embodiment, at step  504 , a determination of whether an update is needed can be made. The determination at step  504  can be made based on a time stamp associated with the type of position assist data stored in memory on device  100 , which can be used by device  100  to derive a time period since the position assist data was last updated. Alternatively, or in addition, the determination at step  504  can be made based on a change in position of device  100 , which may be determined as described herein with reference to  FIG. 10 . 
     In this embodiment, a request for position assist data from a wireless network is made during a wireless communication call established for another application. The position assist data can be interspersed with the voice and/or data communications received from the wireless network in a manner that appears transparent to a user of device  100 . The request from device  100  and/or the data in response to the request from the wireless network can come before, after, or interspersed within the voice and/or data communications. The position assist data may be almanac, ephemeris, MS-assist data, or other position assist data. 
     In an exemplary embodiment, device  100  may determine that an update of a type of position assist data is needed and then may wait until a wireless communication connection or session has been set up for an unrelated purpose and then make the request for position assist data from the wireless network at that time. The request for position assist data can be “piggybacked” on the unrelated wireless communication and the responsive position assist data can likewise be “piggybacked” on the response signal. According to another exemplary embodiment, the request and/or responsive position assist data can be communicated on a control signaling data path, side band frequency, or other channel which may or may not be in use by the voice and/or data call which triggered the request for position assist data. 
     Referring to  FIG. 6A , device  100  may be configured to update  652  position assist data in response to a request  650  from an application for a position fix. Device  100  may be configured to continue to update the position assist data (e.g. may continue to obtain position fixes) after the initial request, based on the receipt of the initial request for the position fix even though no application of device  100  has requested subsequent position fixes. The subsequent position assist data may be obtained immediately (e.g. within 30, 15, 10, 5, and/or 3 minutes) following the initial request for a position fix, or may be obtained after a more extended period of time (e.g. more than 15 minutes, more than 30 minutes, more than 45 minutes, more than 2 hours, more than 4 hours, more than 8 hours, and/or more than 12 hours after the initial position fix request and/or within a week, a day, 16 hours, 12 hours, 8 hours, 6 hours, 4 hours, 2 hours, and/or 1 hour of the initial position fix request). In some embodiments, device  100  may be configured to obtain position assist data (e.g. new position fixes) at least about 1, 2, 3, 4, 5, 6, 7, and/or 8 additional times based on the receipt of the initial request from the application and without position fixes being requested. In some embodiments, device  100  may be configured to obtain position assist data (e.g. new position fixes) a certain number of additional times, which number may be set (e.g. pre-set, calculated, etc.) at or below 50, 30, 25, 20, 15, 10, 8, and/or 5 additional times based on the receipt of the initial request from the application and without position fixes being requested. 
     Referring now to  FIG. 6B , device  100  is configured to generate position assist data periodically at step  600 . At step  602 , if a request for a position fix is received, device  100  maintains the same period of generating position assist data. However, if a period of time X passes without receiving a request for a position fix, then the time period between generating additional position assist data is increased at step  604  by a period Y. In this embodiment, a processor of device  100  is configured to receive a request (e.g., internally from an application or externally from a user or other external application) for a position fix and to provide the position fix based on position assist data stored in memory. The processor may be configured to change the time period between subsequent steps of generating updated position assist data, for example, based on whether a subsequent request for position fix is received from a requester. In this embodiment, the processor is configured to increase the time period a plurality of times between each subsequent request for updated position assist data so long as no subsequent request for position fix is received. This may be referred to as a “throttling” algorithm or other algorithm which increases the time period between subsequent requests for position assist data so long as no request for a position fix is received from a requester. 
     According to one exemplary embodiment, device  100 , after completion of a position fix, will periodically update one or more types of position assist data based on the assumption that there will likely be more position fixes in the near future. According to one embodiment, device  100  assumes that the likelihood of receiving requests for additional position fixes will decrease over time. Therefore, logic is used to determine how frequently to update the position assist data. For example, X minutes after a position fix, device  100  is configured to autonomously, automatically, or without user input, request a position assist data update (e.g., ephemeris data or calculation of coarse data). If a user or other requester has not requested another fix after X plus Y minutes from the last autonomous update of position assist data, device  100  is configured to automatically or autonomously request another update. After a period of time Z without receiving a request for a position fix, device  100  is configured to cease further automatic updates of position assist data according to this algorithm (but may resume requests for position fix data according to other triggering events, such as those described herein). 
     According to one exemplary embodiment, after a position fix is calculated, if no request for a position fix has been received within approximately 60 minutes, device  100  is configured to initiate a request for position assist data without user input. Device  100  is then configured to wait for two hours before autonomously generating additional position assist data for one or more of the position assist data types. Device  100  then may wait four hours (e.g., X=60 minutes plus Y 1 =4 hours), eight hours (e.g., X=60 minutes plus Y 2 =8 hours), etc. before subsequent generations of position assist data. The time periods are merely exemplary and may alternatively be on the order of minutes, days, etc. 
     According to one embodiment, the position assist data is coarse data and device  100  is configured to generate updated coarse data by generating an updated position fix. According to another embodiment, device  100  is configured to periodically generate updated coarse data without regard to whether a request for position fix is received, to compare a plurality of coarse data points, to determine that the device  100  is substantially stationary, and to cease generating further updated coarse data if the device is substantially stationary. In an exemplary embodiment, after comparing X successive position fixes, device  100  determines that it has not moved and subsequent coarse data updates are halted, unless an additional position fix is specifically requested by a user or requester or client. In this embodiment, power consumption can be reduced. 
     Referring now to  FIG. 7 , at step  700 , a mobile computing device ID or other identifying information is stored at a server accessible via a wireless network. The server can be configured to maintain an account for a mobile device and to provide one or more services to the mobile device, such as, backup/restore features for personal information on device  100 , lock/kill pill features to lock and/or clear the memory of device  100  should it be lost or stolen, activation and registration processes for various services, picture messaging, short messaging service (SMS) messaging, multi-media messaging service (MMS) messaging, and other services. 
     The server may further be configured to store a time of last update for one or more types of position assist data, as shown at step  702 . For example, if almanac data is programmed into device  100  at the factory, then the date of manufacture will be used as the last almanac update time initially. The server computer can be configured to track when almanac data expires and to then trigger a “push” or other communication of updated almanac data over a wireless network to device  100 . At step  704 , the server determines whether an update is needed and, if so, updated position assist data is transmitted or pushed to a mobile device  100  at step  706 . The push data for updated position assist data may be done via a data connection, an SMS, or other data downloads. According to one exemplary embodiment, the download of data can be timed during a low use period, such as at night or during a time in which part or all of the device is powered down. The server may further be configured to download the updated position assist data during an existing telephone or data call. The server may further be configured to download the updated position assist data in small portions. For example, the server would not need to track a time stamp of the last update if small chunks of data are periodically sent from time to time over a set time period, such as six months. 
     Referring now to  FIG. 8 , at step  800 , device  100  is configured to store an expiration date for one or more types of position assist data. At step  802 , device  100  is configured to determine whether an update is needed for one or more types of position assist data. For example, device  100  may maintain an expiration date for the position assist data and, upon expiration or reaching the time period for expiration, device  100  autonomously, automatically, or without user input, triggers a request to generate updated position assist data. Alternatively, at step  804  (which can be a process step or represent alternative embodiments), device  100  can determine whether it is configured for a manual update, in which case a user may be notified via the display, a chime, or other indication that one or more types of position assist data have expired. The user may then request via user input to device  100  updated position assist data as shown at step  808 . Step  810  shows the scenario of an automatic request for an updated position assist data. In either event, the request may be sent via a wireless network to a position determination entity (PDE) or to a download server or by linking to a server via a universal resource locater (URL) that points to a location where position assist data may be downloaded (e.g., a U.S. Government website, etc). A user request for position assist data may also be accomplished by sending a text message, such as an SMS or mobile-originated-short message service (MO-SMS), by setting up a data connection to a PDE or another download server on a carrier&#39;s network, or by setting up a data connection to an established public site for almanac data (e.g., U.S. Government website, etc.). 
     According to another exemplary embodiment, device  100  may be configured to provide an indication to a user via the display or speaker (e.g., an icon, chime, tone, etc.) that device  100  is requesting and/or receiving updated position assist data. Advantageously, the user will then know that processing time is being spent on the operation, in the event that sluggish operation is caused for other applications or processes. 
     According to one exemplary embodiment, the download of position assist data may be by method of file transfer and may occur in portions of the complete file. 
     Referring now to  FIG. 9 , at a step  900 , the device  100  detects that it has been powered up. At step  902 , a power up sequence is performed, such as, powering up the processor or processors, enabling the display, etc. At step  904 , if a time stamp check is not required (which may be a process step or represent alternative embodiments), updated position assist data is generated at step  906  automatically, autonomously, and/or without user input. The position assist data may be generated by sending a request for updated position assist data and/or by generating a new position fix to create new coarse data. If a time stamp check is required, at step  908  device  100  determines the period of time since the last update of the type of position assist data and if the period is beyond a predetermined threshold representing “fresh” position assist data, then the process proceeds to step  906  to generate updated position assist data. 
     According to one embodiment, every time device  100  is powered up, updated position assist data of at least one type is generated. 
     According to another embodiment, each time device  100  is powered up, position assist data of at least one type is automatically generated provided a time stamp associated with the data is greater than a predetermined time period representing “fresh” data. 
     According to one embodiment, coarse data may comprise a position fix, a time stamp indicating the time at which the position fix was calculated, and accuracy data indicative of the level of accuracy of the position fix, and/or other data. 
     Referring now to  FIG. 10 , device  100  is configured to detect whether a change in position of device  100  has occurred at step  1000 . If a change in position has been detected of sufficient significance (e.g., greater than a predetermined threshold, or data showing velocity and/or acceleration), at step  1002 , updated position assist data is generated. Device  100  can be configured to detect an event that signals movement of device  100  (e.g., system ID/network ID (SID/NID), overhead message changes, base station (BS) latitude/longitude in overhead message changes beyond some threshold, etc.). Upon detecting this change, device  100  may be configured to automatically, autonomously, or without user input initiate or trigger a request for an update of position assist data. In some embodiments, the decision to update position assist data is based on the number of changes (e.g. changes in SID/NID) identified (e.g. such that a fixed or adjustable threshold number of changes need to be detected before triggering an update and/or that a threshold number of unique identifiers/stations need to be registered before an update is made based on this criteria). 
     Ephemeris data is different based on location. An indication of movement would indicate the possible need for an update of ephemeris data. According to one exemplary embodiment, device  100  is configured to determine whether it moved within 30, 60, 90 minutes or some other predetermined period of time and, if so, the time period of which the position assist data is considered “fresh” or useable may be decreased or reduced to zero. Alternatively, if device  100  indicates that it has not moved, device  100  may be configured to not update the position assist data for the entire predetermined period of time, whether it be 30, 60, 90 minutes or some other period of time. 
     In alternative embodiments, geographic designations other than SID/NID may be used, such as a cellular base station site region, a circular, square or other shaped region with predetermined parameters, etc. 
     Further, while data may be received from an overhead message, such as a signaling message provided continuously to a mobile device over a wireless network regardless of whether a data or telephone communication session has been established, the SID/NID or BS latitude/longitude may be provided over any communication signal. For example, device  100  may configured to receive such an overhead message at very short intervals, such as milliseconds, tenths of seconds, or seconds. The change in position of the device may further be determined by calculating position fixes, such as a stand alone, MS-assist, MS-based, PDE-based, or other position fix. 
     Additionally, every reference to updating position assist data made above is a reference to updating any one type of position assist data, updating any combination of two or more types of position data, and/or updating each type of position assist data. All such variations and combinations are contemplated for each reference above to updating position assist data. 
     With reference to the disclosure and claims, use of the phrase “based on” means “based in least in part on,” and use of the term “a” or “an” means “one or more” or “at least one.” Further, any of the steps of any of the methods disclosed herein may be combined with any of the other steps and/or rearranged with other steps in alternative embodiments. Specifically, various embodiments may make use of different combinations of parts or all of the methods disclosed herein. 
     While the exemplary embodiments illustrated in the Figs., and described above are presently exemplary, it should be understood that these embodiments are offered by way of example only. For example, while some embodiments are shown with reference to receiving position assist data over a wireless network, the teachings herein may also be applied to receiving position assist data from GPS satellites, FM or AM radio signals, other wireless transmissions, wired connections, etc. Accordingly, the present invention is not limited to a particular embodiment, but extends to various modifications that nevertheless fall within the scope of the appended claims.