Patent Publication Number: US-2011060522-A1

Title: Apparatus and method for providing location information service in portable terminal

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY 
     This application claims priority under 35 U.S.C. §119(a) of a Korean patent application filed in the Korean Intellectual Property Office on Sep. 10, 2009 and assigned Serial No. 10-2009-0085249, the entire disclosure of which is hereby incorporated by reference. 
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to an apparatus and method for providing location information in a portable terminal. More particularly, the present invention relates to an apparatus and method for, when the portable terminal enters a shadow area in the course of providing location information, determining a moving pattern of a user and determining whether there is an error between information on the shadow area and a current location of the portable terminal, thus improving the accuracy of the location information. 
     BACKGROUND OF THE INVENTION 
     In recent years, the use of portable terminals has suddenly spread due to their convenience of carrying. Thus, service providers (i.e., terminal manufacturers) are competitively developing the portable terminals that provide more convenient functions to secure many users. 
     For example, the portable terminals are providing functions of a phone book, a game, a scheduler, a Short Message Service (SMS), a Multimedia Message Service (MMS), a Broadcast Message Service (BMS), an Internet service, an electronic mail (e-mail) message, a morning wakeup call, MPEG-1 Audio Layer 3 (MP3), a digital camera, and so forth. 
     Also, the portable terminal may provide a navigation function by receiving a satellite signal, providing traffic information in connection with a traffic information center through a mobile communication network, or providing information on a specific route to a user. 
     The above navigation function, which is a function of storing map data, receiving a satellite signal, and displaying a current mobile location, needs to keep receiving a satellite signal. When the portable terminal enters a shadow area that is not capable of receiving a satellite signal, in order to keep providing location information to a user, the portable terminal estimates a new location within the shadow area, on the basis of the last valid location acquired before shadow area entry, using Pedestrian Dead Reckoning (PDR) information. Until passing through the shadow area or, in other words, until reception of a satellite signal is made possible, the portable terminal provides location information to the user on the basis of the PDR information or, from after a pedestrian enters the shadow area, the portable terminal provides restricted location information to the user based on a defined time and distance. 
     When providing location information using PDR information in a shadow area, because the portable terminal does not reflect a change of the surrounding environment such as when the user of the portable terminal moves indoors and takes an elevator, the portable terminal estimates erroneous location information. 
     For one example, when the user of the portable terminal takes an elevator after entering a shadow area, although the portable terminal is not in movement, the portable terminal will provide the user with previously predicted location information, i.e., erroneous information that the portable terminal is in movement. 
     SUMMARY OF THE INVENTION 
     To address the above-discussed deficiencies of the prior art, one aspect of the present invention is to substantially solve at least the above problems and/or disadvantages and to provide at least the advantages below. Accordingly, one aspect of the present invention is to provide an apparatus and method for providing location information of an improved accuracy in a portable terminal. 
     Another aspect of the present invention is to provide an apparatus and a method for determining the accuracy of the location information for a shadow area in a portable terminal. 
     Yet another aspect of the present invention is to provide an apparatus and method for determining a moving pattern within a shadow area using a plurality of pieces of sensor information acquired before shadow area entry in a portable terminal. 
     The above aspects are achieved by providing an apparatus and method for providing a location information service in a portable terminal. 
     In accordance with an aspect of the present invention, an apparatus for providing a location information service in a portable terminal is provided. The apparatus includes a validity determiner for, by a moving pattern of a user, determining the validity of location information previously predicted using Pedestrian Dead Reckoning (PDR) information. 
     In accordance with another aspect of the present invention, a method for providing a location information service in a portable terminal is provided. The method includes determining, by a moving pattern of a user, the validity of location information previously predicted using PDR information. 
     Before undertaking the DETAILED DESCRIPTION OF THE INVENTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: the terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation; the term “or,” is inclusive, meaning and/or; the phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which like reference numerals represent like parts: 
         FIG. 1  illustrates a portable terminal providing a location information service according to an embodiment of the present invention; 
         FIG. 2  illustrates a process of providing location information in a portable terminal according to an embodiment of the present invention; and 
         FIG. 3  illustrates a process of providing location information in a portable terminal according to an embodiment of the present invention. 
     
    
    
     Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures. 
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 through 3 , discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. 
     The following description is made for an apparatus and method for, in order to provide location information of an improved accuracy, determining a moving pattern within a shadow area using a plurality of pieces of sensor information acquired before shadow area entry in a portable terminal according to the present invention. 
       FIG. 1  illustrates a portable terminal providing a location information service according to an embodiment of the present invention. 
     As shown in  FIG. 1 , the portable terminal may include a controller  100 , a validity determiner  102 , a memory unit  108 , an input unit  110 , a display unit  112 , and a communication unit  114 . The validity determiner  102  can further include a route prediction unit  104  and a moving-pattern determiner  106 . The portable terminal may include additional units. Similarly, the functionality of two or more of the above units may be integrated into a single component. 
     The controller  100  of the portable terminal controls a general operation of the portable terminal. For example, the controller  100  performs processing and control for voice call and data communication. In addition to the general function, in order to provide location information with improved accuracy according to the present invention when the portable terminal enters a shadow area, the controller  100  runs processes to determine the accuracy of the location information while in the shadow area. 
     To perform the above operation, the controller  100  determines a moving pattern of a user (i.e., a moving pattern of a portable terminal) within the shadow area, using a plurality of pieces of sensor information acquired before shadow area entry, and determines whether there is an error between a location moved in the determined moving pattern and a location previously predicted using Pedestrian Dead Reckoning (PDR) information, thus determining the validity of the location previously predicted using the PDR information. 
     In another embodiment, the controller  100  runs processes to determine the validity of the location information predicted through PDR information provided by a shadow area based on a situation (e.g., a building, a subway, an elevator, an escalator, and such) of the shadow area where the portable terminal moves. 
     Under the control of the controller  100 , the validity determiner  102  runs processes to determine a moving pattern of a portable terminal entering a shadow area and predict location information of the portable terminal within the shadow area, and to determine an error between the predicted location and the location previously predicted using the PDR information and determine the validity of the location previously predicted using the PDR information. 
     Under the control of the validity determiner  102 , the moving-pattern determiner  106  comprehends the moving pattern and surrounding environment of the portable terminal using information acquired through a plurality of sensors. 
     For example, the moving-pattern determiner  106  can determine a footstep of a user of the portable terminal using the information acquired from the sensors, determine a movement speed and a movement time using the determined footstep to estimate a pace of the user, and determine whether the user performs an actual walk, using the estimated pace. 
     When the portable terminal enters the shadow area, under the control of the validity determiner  102 , the route prediction unit  104  predicts a movement location of the portable terminal using the PDR information acquired before entering the shadow area and, according to the present invention, the route prediction unit  104  determines whether a user performs an actual walk or the user does not perform the actual walk (e.g., the user moves using an elevator) through the moving-pattern determiner  106 . When determining that the user does not perform the actual walk, the route prediction unit  104  processes to inform the validity determiner  102  that the location information of the portable terminal predicted using the PDR information has no validity. 
     The memory unit  108  includes, for example, a Read Only Memory (ROM), a Random Access Memory (RAM), a flash ROM, and such. The ROM stores a microcode (i.e., code) of a program for processing and controlling the controller  100  and the validity determiner  102  and a variety of kinds of reference data. 
     The RAM, a working memory of the controller  100 , stores temporary data generated in execution of a variety of kinds of programs. The flash ROM stores a variety of updateable depository data such as a phone book, an outgoing message, an incoming message, and information of a user&#39;s touch input point. According to an embodiment of the present invention, the flash ROM stores information acquired through the plurality of sensors. 
     The input unit  110  includes numeral key buttons ‘0’ to ‘9’, a menu button, a cancel button, an OK button, a talk button, an end button, an Internet button, navigation key buttons, a plurality of function keys such as a character input key, and such. The input unit  110  provides key input data corresponding to a key pressed by a user to the controller  100 . 
     The display unit  112  displays state information generated during operation of the portable terminal, a limited number of characters, a large amount of moving pictures and still pictures, and such. The display unit  112  can be a color Liquid Crystal Display (LCD), an Active Mode Organic Light Emitting Diode (AMOLED), and such. The display unit  112  includes a touch input device and thus, when applied to a portable terminal of a touch input scheme, the display unit  112  can be used as an input device. 
     The communication unit  114  performs a function of transmitting/receiving and processing a radio signal of data that is input/output through an antenna (not illustrated). For example, in a transmission mode, the communication unit  114  performs a function of processing original data through channel coding and spreading, converting the original data into a Radio Frequency (RF) signal, and transmitting the RF signal. In a reception mode, the communication unit  114  performs a function of converting a received RF signal into a baseband signal, processing the baseband signal through de-spreading and channel decoding, and restoring the signal to original data. 
     A role of the validity determiner  102  may be implemented by the controller  100  of the portable terminal. However, these are separately constructed and shown in the present invention as an example for description convenience, and never intend to limit the scope of the present invention. It shall be understood by those skilled in the art that various modifications of construction can be made within the scope of the present invention. For example, construction can also be such that all of them are processed in the controller  100 . 
     The above description is made for an apparatus for, in order to provide location information of an improved accuracy, determining a moving pattern within a shadow area using a plurality of pieces of sensor information acquired before shadow area entry in a portable terminal according to the present invention. The following description is made for a method for, in order to provide location information of an improved accuracy, determining a moving pattern within a shadow area using the apparatus according to the present invention. 
       FIG. 2  illustrates a process of providing location information in a portable terminal according to an embodiment of the present invention. 
     As shown in  FIG. 2 , in block  201 , the portable terminal receives location information. In block  203  the location information of the portable terminal is provided to a user. 
     In block  205 , the portable terminal performs a process of determining whether the portable terminal enters a shadow area such that it is not capable of receiving the location information. 
     If the portable terminal does not enter the shadow area, the portable terminal returns to block  201  and processes to keep receiving the location information and provides the received location information to the user. 
     If the portable terminal enters the shadow area, the portable terminal proceeds to block  207  and determines a moving pattern of a user entering the shadow area. Also, when the portable terminal enters the shadow area, the portable terminal performs a general operation of predicting a user location through PDR information. 
     The portable terminal then performs a process of determining whether the location information in the shadow area is valid using the moving pattern of the user. 
     A way to determine whether location information in a shadow area is valid as above is as follows: 
     determining validity depending on whether a user performs an actual walk in the shadow area; and 
     determining validity through a comparison between a location predicted through PDR information and location information predicted according to a moving pattern of a user. 
     First, prior to determining validity through a comparison between a location predicted through PDR information and location information predicted according to a moving pattern of a user, the portable terminal proceeds to block  209  and performs a process of predicting a location of a user using a moving pattern of the user. Here, the portable terminal determines the moving pattern such as a user&#39;s gait and a use of other movement means (e.g., an elevator, and such). 
     In block  211 , the portable terminal determines whether a location predicted through the PDR information is the same as the location predicted using the moving pattern of the user. That is, the portable terminal determines whether the user of the portable terminal is moving along a route predicted through the PDR information that was acquired before the portable terminal enters the shadow area. 
     If the location predicted through the PDR information is consistent with the location predicted using the moving pattern of the user, the portable terminal proceeds to block  213  and performs a general operation of the portable terminal of providing information predicted using the PDR. 
     On the other hand, if determining that the location predicted through the PDR information is not consistent with the location predicted using the moving pattern of the user, the portable terminal proceeds to block  215  and provides the user with a message that the information (i.e., the location predicted using the PDR information) has no validity, as the portable terminal does not actually move to the location predicted using the PDR information. 
     Second, when determining validity depending on whether a user performs an actual walk in a shadow area, the portable terminal may determine a situation (e.g., a building, a subway, an elevator, an escalator, and such) of the shadow area to which the portable terminal moves using sensor information acquired before shadow area entry and, if determining the situation of the shadow area, the portable terminal determines that location information of the shadow area previously predicted through PDR information has no validity. When determining the validity depending on whether the user performs the actual walk in the shadow area as above, the moving pattern of block  207  can be the situation of the shadow area. 
     After that, the portable terminal terminates the process according to an embodiment of the present invention. 
       FIG. 3  illustrates a process of providing location information in a portable terminal according to an embodiment of the present invention. 
       FIG. 3 , in block  301 , the portable terminal performs a Global Positioning System (GPS) function. In block  303 , the portable terminal performs a process of receiving satellite information. 
     In block  305 , the portable terminal provides a general GPS service of providing location information of the portable terminal using the received satellite information. 
     Then, the portable terminal proceeds to block  307  and determines whether it receives a satellite signal. This is a process of determining whether the portable terminal enters a shadow area that is not capable of receiving a satellite signal in the course of performing the GPS function of providing location information. 
     If it receives the satellite signal, the portable terminal returns to block  303  and again performs a process of receiving satellite information. 
     Alternatively, if the portable terminal fails to receive the satellite signal upon entering the shadow area, the portable terminal proceeds to block  309  and, through a plurality of sensors, acquires information for determining a moving pattern of a user who enters the shadow area. 
     Here, the information for determining the moving pattern of the user is information for determining footstep information of the user (i.e., a pedestrian) of the portable terminal and can be, for example, azimuth information for magnetic north acquired from a geomagnetic sensor, angular velocity information acquired from a gyro sensor, current height information of the pedestrian acquired from a height sensor, and so forth. When the user moves while using the GPS function, the portable terminal can operate the plurality of sensors to acquire and store information dependent on a movement of the user. 
     In block  311 , the portable terminal performs a process of determining a moving pattern including the user footstep, movement speed, footstep pattern, and such. 
     In detail, block  311  is a process of, when the portable terminal enters a shadow area, determining the user footstep using previously stored information acquired from the sensors, determining a movement speed and a movement time using the determined footstep to estimate a pace of a user, and determining whether the user performs an actual walk using the estimated pace. This is to prevent provision of erroneous information when the user does not perform an actual walk. 
     In block  313 , the portable terminal performs a process of comprehending the surrounding environment of the user of the portable terminal located in the shadow area. 
     Here, the process of comprehending the surrounding environment is to determine information on the surroundings of the user of the portable terminal. The user of the portable terminal comprehends a situation such as when using a shadow area (i.e., a subway, an elevator, an escalator, and such). 
     For example, if entering a shadow area, the portable terminal can determine information on the surroundings such as when a user takes a subway or an elevator after entering the shadow area, by comparing a variance of data of a geomagnetic sensor with a variance of an integral value of data of a gyro sensor. At this time, if a value of the geomagnetic sensor greatly varies because of a magnetized object existing around the portable terminal, in order to reduce the occurrence of an error, the portable terminal estimates a pedestrian&#39;s advance direction using the data of the gyro sensor on the basis of previous valid data of the geomagnetic sensor. 
     In block  315 , the portable terminal determines whether the user of the portable terminal moves to a location predicted through PDR information. Here, block  315  refers to a process of, if the portable terminal enters the shadow area, determining whether there is an error between a location predicted using valid data before the shadow area entry and a location predicted according to the moving pattern of the portable terminal according to the present invention. 
     If the portable terminal moves to the location predicted through the PDR information in block  315 , the portable terminal proceeds to block  317  and performs a general operation of providing information predicted using the PDR. 
     Alternatively, if the portable terminal does not move to the location predicted through the PDR information in block  315 , for example, if determining surroundings information such as the use of an elevator after entering the shadow area, the portable terminal proceeds to block  319  and provides the user with information that the information (i.e., the location predicted using the PDR information) has no validity as there occurs an error between the location predicted using the PDR information and the location predicted according to the moving pattern of the portable terminal. 
     After that, the portable terminal terminates the process according to an embodiment of the present invention. 
     As described above, the present invention is to provide location information of an improved accuracy in a portable terminal and, by determining a moving pattern within a shadow area using a plurality of pieces of sensor information acquired before shadow area entry, the present invention can provide more accurate location information than an existing portable terminal that provides limited location information irrespective of a change of a pedestrian&#39;s surrounding environment, a movement means, and such. 
     While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.