Patent Publication Number: US-2011057835-A1

Title: Method and apparatus for determining location using a hybrid solution

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation of Non-Provisional U.S. patent application Ser. No. 12/052,504, filed on Mar. 20, 2008, which claims priority under 35 U.S.C. §119(e) to provisional U.S. Patent Application No. 60/896,098, filed on Mar. 21, 2007, the disclosure of which is expressly incorporated by reference herein in its entirety, and this application further claims priority under 35 U.S.C. §119(e) to provisional U.S. Patent Application No. 60/912,551, filed on Apr. 18, 2007, the disclosure of which is expressly incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     1. Field 
     The method and apparatus are directed generally to using multiple signal source types to determine location, and more particularly to using multiple signals source types to increase accuracy of a location determination and/or reduce power usage therewith, and/or shortening time required to make a location determination. 
     2. Related Art 
     There currently exist a number of location determination methods and apparatuses. None of these methods and apparatuses is necessarily perfect or operates in all situations. There is typically a trade-off between accuracy, power consumption, sensitivity, and cost. 
     For example, one common system is the Global Positioning System (GPS). The GPS system is a global navigation satellite system. It utilizes a constellation of medium earth orbit satellites that transmit precise microwave signals. These signals allow a GPS receiver to determine a position location, for example by triangulation. 
     GPS signals typically are transmitted at a particular frequency (about 1.575 GHz). Such a frequency may be strongly attenuated by buildings and other man made structures, or have a tendency to be affected by multi-path signals created by an urban environment or affected by inconsistencies in atmospheric conditions, for example. Accordingly, suitable GPS signals may not be always available to a GPS receiver. 
     Various attempts have been made to create alternatives that overcome the disadvantages of the GPS system, for example location determination employing digital television transmitters, cell phone base stations, Wi-Fi or Wi Max access points and the like. Signals from other transmitters may also not be optimal. 
     SUMMARY 
     In accordance with an embodiment of the invention, a hybrid combination of several different location processes for location determination is disclosed. The disclosed method and apparatus takes advantage of selected location determination methods to support greater reliability any time and any where, to calculate the position location. In an embodiment, the GPS location system may be used as the core method for location determination and the other various location systems may be used in conjunction with the GPS in a hybrid fashion. The hybrid use of several different systems facilities location determination even if one method or a portion of one method does not exist or is not available to provide a proper location. This hybrid solution may be configured to employ the system which offers the best accuracy, power consumption, and/or sensitivity or any combination of location determination methods at the platform. 
     There is thus provided in accordance with an embodiment of the invention a device for location determination that includes a first receiver configured to receive at least one signal from a first transmitter, a second receiver configured to receive at least one signal from a second signal transmitter, the first receiver is configured to receive a first type of signal and the second receiver is configured to receive a second type of signal different from the first type of signal, a signal quality processor configured to assess a quality of signals received by the first receiver and the second receiver, and a location calculator that determines a location of the device using the first type of signal and the second type of signal in response to a signal quality assessment. 
     In accordance with another embodiment of the invention, a method for location determination includes receiving at least one signal from a first transmitter, receiving at least one signal from a second transmitter, the first transmitter transmits a first type of signal and the second transmitter transmits a second type of signal different from the first type of signal, assessing a signal quality of received signals received from at least one of the first signal transmitter and second signal transmitter, and determining a location of a device using the received first and second type of signals at least from both the first transmitter and from the second transmitter. 
     In accordance with yet another embodiment of the invention, a device for location determination includes a first receiver configured to receive at least one signal from a first transmitter, a second receiver configured to receive at least one signal from a second signal transmitter, the first receiver is configured to receive a first type of signal and the second receiver is configured to receive a second type of signal different from the first type of signal, a signal processor configured to assess accuracy of signals received by the first receiver and the second receiver, and a location calculator that determines a location of the device using the first type of signal and the second type of signal in response to a signal assessment. 
     In accordance with an embodiment of the invention, a reduced power consumption wireless local area network device includes a location determination mechanism configured to determine a change in location responsive to at least one of GPS, Cellular, or television signals, the location determination mechanism uses more than one of GPS, Cellular, or television signals when one of GPS, Cellular, or television signals alone are not sufficient, and an access point selector configured to initiate an access point scan when the location determination mechanism determines a change in location. 
     In accordance with a further embodiment a process for reduced power consumption in a wireless local area network includes determining a change in location responsive to at least one of GPS, Cellular, or television signals, wherein the location determination uses more than one of GPS, Cellular, or television signals when one of GPS, Cellular, or television signals alone are not sufficient, and initiating an access point scan when the location determination mechanism determines a change in location. 
     Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are and intended to provide further explanation without limiting the scope of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate and teach embodiments of the invention. No attempt is made to show structural details in more detail than may be necessary to teach examples of various ways in which embodiments of the invention may be practiced. In the drawings: 
         FIG. 1  shows a combination of hybrid signals used to determine location; 
         FIG. 2  shows another combination of hybrid signals used to determine location; 
         FIG. 3  shows another combination of hybrid signals used to determine location; 
         FIG. 4  shows an architecture for a processor arrangement constructed according to the principles of an embodiment; 
         FIG. 5  shows a construction of a location server constructed according to the principles of an embodiment; 
         FIG. 6  shows a hybrid location determination process operating according to the principles of an embodiment; 
         FIG. 7  shows a process to save power operating according to the principles of an embodiment; 
         FIG. 8  shows a system for use with the  FIG. 7  embodiment; 
         FIG. 9  shows a chart of the possible hybrid signal combinations operating according to the principles of an embodiment; 
         FIG. 10  shows a vehicle control system constructed according to the principals of an embodiment; and 
         FIG. 11  shows a cellular phone/PDA/WLAN User Equipment (UE) constructed according to the principals of an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The embodiments of the invention and various features are explained more fully with reference to the non-limiting embodiments and examples that are described and/or illustrated in the accompanying drawings and detailed in the following description. It should be noted that the features illustrated in the drawings are not necessarily drawn to scale, and features of one embodiment may be employed with other embodiments, even if not explicitly stated herein. Descriptions of well-known components and processing techniques may be omitted so as to not unnecessarily obscure teaching principles. The examples used herein are intended merely to facilitate an understanding of ways in which the invention may be practiced. Accordingly, the examples and embodiments herein should not be construed as limiting the scope of the invention, which is defined solely by the appended claims and applicable law. Moreover, it is noted that like reference numerals represent similar parts throughout the several views of the drawings. 
     An aspect of the invention is directed to using a hybrid combination of signals of different signal source types to determine a location of a user and/or user device. For example in  FIG. 1 , a GPS satellite signal source  102 , a first TV signal source  104  and a second TV signal source  106  all emitting position location signals. The GPS signal source  102  emits a GPS signal  112 , the first TV signal source  104  emits a position location signal  114 , and the second TV signal source  106  emits a position location signal  116 . In accordance with an embodiment the combination of these signals  112 ,  114 ,  116  are used to more reliably, more efficiently, more robustly and/or in a relatively shortened period of time to locate a user and their position location device  120 , for example when signals from one of the signal sources  108  is completely or partially obscured such as by a building. Although signal sources  108  are depicted as being ground based, it is appreciated that one or more of these sources may be a GPS transmitter. 
       FIG. 2  shows another implementation of the hybrid system. In this embodiment, a GPS signal source  102  emits a position location signal  112 , a first cellular based station  204  emits a position location signal  214  and a second cellular based station  206  emits a position location signal  216 . Again the hybrid combination of signals is able to more efficiently, more reliably, more robustly and/or in a relatively shortened period of time determine the location of a user and their position location device  120  when signals from one of the signal sources  108  is completely or partially obscured such as by a building. 
       FIG. 3  shows another implementation of the hybrid system. In this embodiment, a GPS signal source  102  emits a position location signal  112 , a first cellular based station  204  emits a position location signal  214  and a TV signal source  106  emits a position location signal  116 . Again the hybrid combination of signals is able to more efficiently, more reliably, more robustly and/or in a relatively shortened period of time determine the location of a user and their position location device  120  when signals from one of the signal sources  108  is completely or partially obscured such as by a building. 
     In accordance with embodiments of the invention, improvements in location determination are achieved by using best signals from among those available. As shown in  FIGS. 1-3 , the invention may be implemented a number of different ways using a number of different types of position signals. Described in further detail below is a particular implementation of a device that is able to operate, receive and determine the location of a user in a hybrid manner using signals from different types of sources as shown in  FIGS. 1-3  above. Further described below in detail is a process that may be used with the device or may be used in another device able to use a hybrid group of signals to determine the location of a user as described in reference to  FIGS. 1-3  above. It should be noted that  FIGS. 1-3  are merely examples of possible combinations of signals from different types of sources. Any combination of signals that are emitted from an emitter having a known location, or otherwise provide a position location reference may be used. The implementation of the above-noted functionality may be implemented with a plurality of receivers that are capable of receiving the various position determination signals. Additionally, the device may include a calculator that may be implemented to determine a location based on the plurality of the different types of signals. Finally, the apparatus may include a location signal quality processor, to determine when the signals from the plurality of receivers may be used. An apparatus that provides the above-noted functionality will now be described in detail. 
     In particular,  FIG. 4  shows an example of hardware architecture  300  suitable for hybrid signal location determination. The hybrid signal location determination architecture  300  may be configured to receive signals from various different signal source types to provide location information for a user, for example. The hybrid signal location determination architecture  300  may be divided into two operational portions. As shown in  FIG. 4 , a first portion is an applications section  302 , and the second portion is a communications section  304 . 
     The applications section  302  may include a location server  340 . The location server  340  may be connected through an OS location driver  306  (or otherwise responsive) to location applications  308 . This arrangement may allow for location activities, administration, registration purposes or so on in order to improve the use of diverse location functions and to improve power consumption at an application side. The location applications  308  may include request and configuration sections to interact with the OS location driver  306 . In some cases, the location server  340  may include functionality to provide for all location activities at a platform level. This may be particularly beneficial when cellular communication signals are used for location determination. And this may be more particularly beneficial when certain levels of permission are required from a cellular operator&#39;s side of operation. In this regard, permission is needed in order to use location methods controlled by a cellular network. These include cellular identification, EOTD/OTDOA, advanced GPS and a matrix applications. The location server  340  may further include a location server operations, administration, and maintenance section (OA&amp;M)  310 . The location server  340  may manage the location functionality on an application side. This is particularly true for such signal sources as advanced GPS, DVB-H, Wi-Fi and other similar location methods. The management may further be executed by the location server OA&amp;M  310 . In some particular cases, the location server OA&amp;M  310  may manage all the location functionality at a platform level. The location server  340  may also include a hybrid block  312 . The hybrid block  312  may include numerous functions including signal measurement, data &amp; control, position calculation and so on for each of the available location signal types. Moreover, the hybrid block  312  may be able to determine position and perform a calculation from a mix of location signal types available. 
     The location server  340  may also include a database  314 . The database  314  may be used to store various parameters. In particular, the database  314  may store location parameters such as aiding data, last location, application configurations, other measured parameters, and so on. The location server  340  may include an adaptation layer  316 . The adaptation layer  316  may include functionality to coordinate various signals. The various signals may include data, control, measurements, and so on. Moreover, the various signals may be signals transmitted between the location server OA&amp;M  310  and the hybrid block  312 . The location server  340  may also include a GPS stack user plan  318 . The GPS stack user plan  318  may be used to communicate with the advanced GPS client  328  amongst other things. Moreover the GPS stack user plan  318  may further utilize logic channels for data and control. The location server  340  may further include a Wi-Fi client  320 . The Wi-Fi client  320  may include functionality to coordinate the communication side, the Wi-Fi stack, or the Wi-Fi stack of a control plan of a communication side with a Wi-Fi component  322 . 
     The location server  340  may also include a DVB-H client  324 , for example. The DVB-H client  324  may be used to coordinate the communication side, the DBV-H stack and/or the DBV-H stack control plan of the communications side with a DVB-H component  326 . 
     The location server  340  may also include an AGPS client  328 . The AGPS  328  may be used to coordinate the communications side, the AGPS stack for user plan on an application side, and/or an AGPS stack of a control plan on the communications side with the AGPS component  330 . Any other(s) clients  384  and other(s) components  382  are contemplated for use with the invention including HDTV. 
     It should be noted that the hybrid block  312 , the database  314 , adaptation layer  316 , GPS stack user plan  318 , the Wi-Fi client  320 , DVB-H client  324 , and the AGPS client  328  may or may not be utilized in embodiments as described above. Moreover, these components may be combined as shown or located elsewhere within the system. The particular implementation noted above is merely provided as a teaching example. 
     Next, the hybrid signal location determination architecture  300  includes an operating system (OS)  332 . The OS  332  may also be on the applications section side  302  of the hybrid signal location determination architecture  300 . The OS  332  may interact with the location server  340 , the operating system location driver section  306 , and/or the location applications section  308 . 
     The hybrid signal location determination architecture  300  may also include the communications section  304 . The communications section  304  may interact and exchange signals with the applications section  302 . In particular, the communications section  304  may include a communications protocol stack  334 , for use with systems such as GSM and/or WCDMA. The communications protocol stack  334  may also interact with and/or be responsive to a GPS stack  336 . The GPS stack  336  may interact with a communications interface (IF)  338 . The communications interface  338  may receive data and control signals from the applications section  302 . The communication interface  338  may also interface to the communications protocol stack  334  with L 1  aiding, time, frequency signals and so on signaling. The communications protocol stack  334  may also provide various timing pulse, clock signals, hardware signals and so on to the advanced GPS (AGPS) component  330 . 
       FIG. 5  shows an example of a location server constructed and arranged in accordance with an embodiment. In particular,  FIG. 5  shows an implementation of the hybrid block  312  in greater detail. In this implementation, the hybrid block  312  may include a hybrid position calculation portion  372 , a position signal measurement portion  374 , a location resources controller  376 , and a location data portion  378 . In particular, the position signal measurement portion  374  may be configured to measure a timing of signals received from the various types of transmitters (GPS, HDTV, cellular, AP, etc.). The hybrid position calculation portion  372  may then be responsive to the position signal measurement portion  374  and accordingly calculate a position of the user or the mobile station responsive to the measurement determined by the position signal measurement portion  374 . 
       FIG. 6  shows an example of a process that may be implemented in accordance with an embodiment of the invention. In particular,  FIG. 6  shows a hybrid location determination process  500 . Initially at  502 , a location application request/response  502  may be initiated from the user or as is normally initiated during operation of the mobile station. The first step is to determine whether or not any location method is currently active as shown by  504 . If a location method is currently active, then the flow at logic may move to  506 . In  506 , a determination may be made as to whether or not the signals received meet the application requirements for determining a location. The requirements may include for example an assessment of the application requirements for position location, the signal strength of the various types of signals received in the apparatus, transmitter availability of the various signals source types, a power of the signals received in the device, and/or accuracy of the signals received into the device. This relates to precision accuracy location of the transmitter providing the signals. For example, the location of a GPS satellite may be more precisely known than the location of some signal source. Other factors may also contribute to determining whether or not particular application requirements are met. 
     If, as shown in  506 , the application requirements are met for any selected location determination method then the logic may flow to  508 . In  508 , a determination may be made whether or not there is a solution to the position determination. If there is a solution, then the process may end in  510  with the determination of the position. However, if any one of the previous steps to  504 ,  506 ,  508  is negative then a hybrid solution may be sought as shown by the process in  512 . Accordingly, the hybrid mechanism process  512  may be implemented in order to obtain the best possible location determination from a hybrid solution. 
       FIG. 7  shows an example of a process for saving power in a device for location determination using hybrid signals in accordance with another embodiment of the invention. This aspect may be used in conjunction with the hybrid solution noted above or any other position location system. Further, this aspect may be used with any wireless local area network (WLAN), but other wireless systems are contemplated. 
     In particular  FIG. 7  shows a power-saving process for mobile wireless network devices such as devices that include a WLAN transceiver, such as a mobile station that communicates with a WLAN that may implement a station scan mode. In particular, the power-saving process  600  may be utilized with or without the above-noted hybrid location process and/or apparatus. In the prior art, when a WLAN transceiver is not associated with a particular signal source, the WLAN transceiver needs to scan for new access points about every  60  seconds. Of course other timeframes are contemplated. 
     On the other hand, the WLAN transceiver does not need to update with a station scan mode unless it moves. Updating only in a response to a change in position based on a position determination consumes significantly less energy, and therefore increases battery life of the WLAN transceiver. During the prior art usage of a WLAN transceiver, the WLAN transceiver needed to scan about 14 channels in the 2.4 GHz ban; and optionally, 12 additional channels in the 5 GHz ban. For each channel, the power consumption may be about 300 mW for about 100 msec. The resultant average power consumption due to scanning every 60 seconds is therefore about 13 mW. 
     The power-saving process  600  may be used in conjunction with a position termination process and/or device in order to reduce the instances when the WLAN transceiver has to enter a scan mode. In particular, a WLAN station may have a typical power consumption of about 13 mW. In contrast, when a WLAN transceiver utilizes a location algorithm the power consumption may be reduced to about 28-592 μW, that results in a reduced power consumption (about 22-464 times better). 
     Using the power-saving process  600  shown in  FIG. 7 , the power consumption for position determination is in the range of about 28 to 592 μW during the same period. An example of a process using a position determination process, such as a GPS-type position determination process, in accordance with an embodiment of the disclosure will now be described with reference to  FIG. 7 . 
     In  602 , a WLAN transceiver may be operating but is not associated with an access point. In  604 , the WLAN transceiver transitions to an idle or active mode. At this point in time, the WLAN transceiver may be transmitting and receiving data as is well known in the art. Conventionally, approximately every 60 seconds (or other predetermined period of time) when a WLAN transceiver may be operating in an idle/active mode, the WLAN transceiver may enter a scan mode to determine signal sources and the like. However, in the power-saving process  600 , unless there is a position change the WLAN transceiver may not enter a scan mode. A position change may be ascertained by using a position determination algorithm such as the hybrid system described above or some other conventional location system. For example, a location system may obtain an initial location fix as shown in  608 . Thereafter, the location system may execute low power tracking as shown in  610 . And thereafter, the location system may obtain a location of the WLAN transceiver as shown in  612 . During the normal idle/active mode  604 , the WLAN transceiver may determine whether or not there is a location change computed using signals from GPS system and the like, other hybrid sources that exceeds a position change threshold as shown in  606 . This location change may be determined from the location process  612 . If the location change does not exceed a threshold, then the flow of the process may return the WLAN transceiver to the idle/active mode thereby avoiding the high-power consumption scan mode as shown in  608 . However, should the WLAN transceiver location be changed such that it exceeds a threshold, the flow of logic in  606  may move to  608 . In  608 , the WLAN transceiver may enter a scan mode in order to determine if an access point exists that provides better reception and the like. 
     This power-saving process may be used with a WLAN transceiver or any other type of transceiver that requires a higher power consumption mode caused by geographic movements of the device. Additionally, although a location system is referred to in the power-saving process  600 , other location determination processes including the hybrid process described above are also contemplated. In particular, the power-saving process  600  may be utilized with or without the above-noted hybrid location process and/or apparatus. Moreover, other forms of sensing are contemplated to determine a change in location including accelerometers. 
       FIG. 8  shows a system for use with the  FIG. 7  embodiment. In particular,  FIG. 8  shows a mobile station  820  receiving signals  804  from WLAN access points  802  and TV signals  114  from a TV source  104 . The GPS SV (Space Vehicle)  102  may not be able to provide a position signal. Thus, mobile station  820  may be determining location using a hybrid solution as described above. Using the process of  FIG. 7 , the mobile station  820  may save power by not using a scan mode until the mobile station  820  moves, as shown by arrow A, and then the scan mode may be implemented. 
       FIG. 9  shows a chart of the possible hybrid signal combinations operating according to the principles of the invention. The left column shows the configuration and the right columns show the base station (BS) type. In particular, the first four rows show the basic configuration of using satellites for the GPS location determination, using base stations (BTS) cellular location determination, digital television (DTV) signals for television location determination, and Wi-Fi access points (AP) for Wi-Fi location determination. The chart of  FIG. 9  further shows different possible combinations or mixes of the location determination signals. Other combinations of signals are contemplated including more than two types of signals. 
     In accordance with various embodiments of the invention, the methods described herein are intended for operation with dedicated hardware implementations including, but not limited to, semiconductors, application specific integrated circuits, programmable logic arrays, and other hardware devices constructed to implement the methods and modules described herein. Moreover, various embodiments described herein are intended for operation as software programs running on a computer processor. Furthermore, alternative software implementations including, but not limited to, distributed processing, component/object distributed processing, parallel processing, virtual machine processing, any future enhancements, or any future protocol can also be used to implement the methods described herein. 
     It should also be noted that the software implementations of the invention as described herein are optionally stored on a tangible storage medium, such as: a magnetic medium such as a disk or tape; a magneto-optical or optical medium such as a disk; or a solid state medium such as a memory card or other package that houses one or more read-only (non-volatile) memories, random access memories, or other re-writable (volatile) memories. A digital file attachment to email or other self-contained information archive or set of archives is considered a distribution medium equivalent to a tangible storage medium. Accordingly, the invention is considered to include a tangible storage medium or distribution medium, as listed herein and including art-recognized equivalents and successor media, in which the software implementations herein are stored. Referring now to  FIGS. 10 and 11  are various examples of devices in which systems and methods disclosed hereinabove may be implemented. 
     Referring now to  FIG. 10 , a hybrid system and method for location determination may be implemented in a control system of a vehicle  430 . 
     The invention may be embodied in a control system  440  of vehicle  430 . The control system  440  may likewise receive signals from input sensors  442  and/or output control signals to one or more output devices  444 . In some implementations, control system  440  may be part of an anti-lock braking system (ABS), a navigation system, a telematics system, a vehicle telematics system, a lane departure system, an adaptive cruise control system, a vehicle entertainment system such as a stereo, DVD, compact disc and the like. Still other implementations are contemplated. The control system  440  may support connections with a WLAN via a WLAN network interface  448 . 
     Referring now to  FIG. 11 , the hybrid system and method for location determination may be implemented in a device  450 , such as a cellular phone, PDA, or WLAN UE that may include an antenna  451 . The invention may implement either or both signal processing and/or control circuits, which are generally identified in  FIG. 11  at  452 , a WLAN interface and/or mass data storage of the device  450 . In some implementations, cellular phone  450  includes a microphone  456 , an audio output  458  such as a speaker and/or audio output jack, a display  460  and/or an input device  462  such as a keypad, pointing device, voice actuation and/or other input device. Signal processing and/or control circuits  452  and/or other circuits (not shown) in the cellular phone  450  may process data, perform coding and/or encryption, perform calculations, format data and/or perform other cellular phone functions. 
     Although reference is made to some specific wireless protocols, any wireless protocol is within the scope of the invention. For example, Bluetooth, wireless-fidelity (Wi-Fi-IEEE 802.11), fixed wireless access (WiMAX-IEEE 802.16), ultra wideband (UWB), WCDMA (wideband code-division multiple access) or any other known technology using a licensed or unlicensed frequency band. Moreover, any future enhancement of a current protocol or any future protocol is contemplated for use with the invention. 
     While the invention has been described in terms of exemplary embodiments, those skilled in the art will recognize that the invention can be practiced with modifications in the spirit and scope of the appended claims. These examples given above are merely illustrative and are not meant to be an exhaustive list of all possible designs, embodiments, applications or modifications of the invention.