WO2005002089A1

WO2005002089A1 - A method for providing navigation service by using location of a mobile terminal and a system thereof

Info

Publication number: WO2005002089A1
Application number: PCT/KR2003/002223
Authority: WO
Inventors: Jin Beom Kim; Hee Back Lee
Original assignee: Thinkware Systems Corporation
Priority date: 2003-06-27
Filing date: 2003-10-22
Publication date: 2005-01-06
Also published as: AU2003273092A1; JP4316565B2; JP2007520684A; KR100555104B1; KR20050004311A

Abstract

The present invention relates to a method for providing navigation service by using the location of a mobile terminal and a system thereof. The method comprises the steps of (1) detecting positioning information of a user’s first terminal; (2) receiving the above information as departure information; (3) receiving prescribed destination information; (4) outputting prescribed route information based on the above departure and destination information; (5) providing the above output information with the above user’s first terminal; (6) estimating whether a global positioning system (GPS) can be received from the above user’s second terminal; (7) correcting the above route information based on the above user’s positioning information which is outputted through the above GPS signal if it is possible to receive a GPS signal; and (8) providing the above corrected route information to the above first terminal.

Description

A METHOD FOR PROVIDING NAVIGATION SERVICE BY USING LOCATION OF A MOBILE TERMINAL AND A SYSTEM THEREOF

Technical Field The present invention relates to a method for providing a navigation service using location information of a mobile terminal, and more particularly, to a method for providing a predetermined navigation service using location information of a base station within the radius of a cell where a mobile terminal is located, even when the GPS receiver of a user does not work properly.

Background Art A navigation system is a system that provides traffic information to cars such as automobiles using an artificial satellite and is also referred to as an automatic navigating system. Such a navigation system receives predetermined data from Global Positioning System (GPS) satellites orbiting the earth using a GPS receiver and calculates its own position based on the received data. There are a number of GPS satellites orbiting the earth. A navigation system can receive GPS signals from three GPS satellites no matter where the vehicle is located on the earth and calculate its own position based on the GPS signals received from the three GPS satellites. The navigation system provides a variety of traffic information to cars such automobiles based on the information on its own position calculated as such. Although this navigation system has been usually employed in the position determination for and the navigation of large carriers such as aircrafts or ships, it has recently been widely used even in the automobiles and the like. The navigation system provides a user with a variety of information including current location information of a car, routing information from a current location to a destination of a car, map information related to the position and routing information, traffic information and the like. In such a navigation system, a GPS receiver for receiving predetermined GPS signals from GPS satellites is usually provided to a user who wants to use a navigation service. Generally, such a GPS receiver is designed so that it can be mounted in the user's car, and a predetermined navigation service is provided to the user based on information of the position of the user that is calculated by the GPS receiver. Further, a mobile terminal including such a GPS receiving module therein has been recently developed. Even a PDA (Personal Digital Assistant) can also include a predetermined GPS module therein in order to provide GPS receive capability. This conventional navigation system has the following problems: (1) If a GPS receiver is first powered on or has not been used for a long time or if a user moves a long distance (usually about 300 miles) with the GPS receiver turned off, it takes a predetermined time for the GPS receiver to receive GPS signals from one or more GPS satellites and to calculate the current position of the user. This is a so-called "cold start". In such a state, the GPS receiver has no information on the available GPS satellites. Even though the GPS receiver has a little information, the GPS receiver should be again initialized since the current location of the GPS receiver and the position of the GPS satellites do not match. Thus, the GPS receiver scans all the GPS satellites to collect information on available GPS satellites, performs the process of synchronizing with the available GPS satellites and then calculates its own position. In this case, it takes from 90 seconds to 10 minutes or more for the GPS receiver to receive signals from the GPS satellites and calculate its own position after the GPS receiver has been turned on. In case of a GPS receiver used in Asia at the "cold start" state, the GPS receiver calculates its own current position based on GPS signals which are received by using Tokyo, Japan as a reference position. In such a case, it takes considerable time to obtain information on the current position of the user. Accordingly, there is a problem in that in the cold start state, a user should wait for considerable time to use a predetermined navigation service, i.e. until the GPS receiver operates normally. (2) Even though the GPS receiver is turned on again after it has been turned off, it also takes some time for the GPS receiver to receive GPS signals from one or more GPS satellites and calculate the current position of the user. This is a so-called "warm start". In such a case, information on the GPS satellites is stored in the memory means of the GPS receiver but the GPS receiver should be synchronized again with the GPS satellites when the GPS receiver is newly turned on. That is, it usually takes from 1-2 minutes to 3-4 minutes for the GPS receiver to calculate its own position after it has been turned off and then turned on again. In such a case, it also takes considerable time to obtain information on the current position of the user. Accordingly, there is also a problem in that a user should wait for considerable time to use a predetermined navigation service, i.e. until the GPS receiver operates normally. (3) Further, GPS signals may not be received due to a variety of reasons other than the aforementioned cold start or warm start state, and the reception of GPS signals may be interrupted due to various causes while a user drives a car. Therefore, there is a problem in that smooth navigation service cannot be provided to the user due to the aforementioned unexpected reasons. (4) Furthermore, in case of a GPS receiver used in a personal navigation system other than a navigation service used in a car, it is difficult to determine the current position of a user when the user moves toward a predetermined destination from a region (i.e., a subway station, an underground shopping center, etc.) where the user cannot receive GPS satellite signals. For this reason, there is a problem in that a predetermined navigation service cannot be provided to the user. Accordingly, there is a need for a method capable of smoothly providing a predetermined navigation service when a GPS receiver is in a "cold start" or "warm start" state or even when the reception of GPS signals is interrupted due to a variety of reasons.

Disclosure of Invention A method for providing a navigation service using location information of a mobile terminal according to the present invention is conceived to solve the aforementioned problems in the prior art. The present invention aims to provide a user with predetermined path information by using location information of a mobile terminal of the user without predetermined standby time even when a GPS receiver is in a cold start or warm start state. Further, the present invention aims to provide a user with predetermined path information by using location information of a mobile terminal of the user even when a

GPS receiver mounted into a car does not work well due to a number of given problems. Furthermore, the present invention aims to provide a user with predetermined path information by using location information of a mobile terminal of the user even when the user is located at a region where the user cannot receive GPS signals via a personal navigation system. The present invention also aims to minimize unnecessary communication fees or standby time by allowing a navigation service to be made using previously provided path information and map data even though a user resumes driving a car after the user stops the car for a short time while using the navigation service or after the user did not use the car for a long time. In addition, the present invention aims to minimize unnecessary communication fees and standby time, which are produced due to the reception of additional path information and map data, by allowing recently used path information to be stored and the stored path information to be provided to the user at the request of the user. According to the present invention for achieving the objects, there is provided a method for providing a navigation service, comprising the steps of searching location information of a user's first terminal; receiving the searched location information on the first terminal as source information; receiving predetermined destination information; calculating predetermined path information based on the source information and destination information; providing the calculated path information to the user's first terminal; determining whether a user's second terminal can receive GPS signals; correcting the path information on the basis of the user's location information calculated based on the GPS signals, when the second terminal can receive the GPS signals; and providing the corrected path information to the first terminal. In addition, according to an aspect of the present invention, there is provided a method for providing a navigation service, comprising the steps of searching location information of a user's first terminal; receiving the searched location information on the first terminal as source information; receiving predetermined destination information; calculating first path information based on the source information and destination information; providing the calculated first path information to the user's first terminal; determining whether a user's second terminal can receive GPS signals; calculating the user's current location by analyzing the GPS signals, when the second terminal can receive the GPS signals; calculating second path information from the calculated current location to the source; and providing the second path information to the first terminal. In addition, according to another aspect of the present invention, a method for providing a navigation service, comprising the steps of receiving predetermined source information; receiving predetermined destination information; calculating predetermined path information based on the input source information and the input destination information; providing the calculated path information to a user's first terminal; controlling current location information of the user to be stored in a predetermined memory means; determining whether a user's second terminal consistently receives GPS signals; and when it is determined that the user's second terminal does not consistently receive GPS signals, providing to the first terminal the stored current location information of the user and moving direction information on the path information, which is calculated using current moving angle information of the user from a predetermined sensor means. In addition, according to still another aspect of the present invention, there is provided a method for providing a navigation service, comprising the steps of receiving predetermined source information; receiving predetermined destination information; calculating predetermined path information based on the input source information and the input destination information; providing the calculated path information to a user's first terminal; controlling current location information of the user and the path information to be stored in a predetermined memory means; providing the stored current location information and the path information to the first terminal; receiving an acknowledge response for the stored current location information and the path information from the user; and providing the current location information and the path information to the user's first terminal. In addition, according to still another aspect of the present invention, there is provided a method for providing a navigation service, comprising the steps of controlling predetermined path information to be stored in a predetermined memory means; controlling one or more said path information stored in the memory means to be displayed on a user's first terminal; selectively receiving one of one or more said path information displayed on the first terminal from the user; and providing the received path information to the first terminal.

Brief Description of Drawings FIG. 1 is a block diagram illustrating a system for obtaining location information of a mobile terminal, which is used in a method for providing a navigation service by using location information of the mobile terminal according to the present invention. FIG. 2 is a flowchart illustrating steps of embodying a method for providing a navigation service using location information on a mobile terminal according to a first embodiment of the present invention. FIG. 3a is a flowchart illustrating steps for embodying a method for providing a navigation service using location information on a mobile terminal according to a second embodiment of the present invention. FIG. 3b is a view showing an example that path information is recalculated in the method for providing the navigation service shown in FIG. 3 a. FIG. 4 is a flowchart illustrating steps for embodying a method for providing a navigation service using location information on a mobile terminal according to a third embodiment of the present invention. FIG. 5 is a flowchart illustrating steps for embodying a method for providing a navigation service using location information on a mobile terminal according to a fourth embodiment of the present invention. FIG. 6a is a flowchart illustrating steps for embodying a method for providing a navigation service using location information of a mobile terminal according to a fifth embodiment of the present invention. FIG. 6b is a view showing an exemplary screen displayed on a user's mobile terminal in the method for providing the navigation service described with reference to FIG. 6a.

Best Mode for Carrying Out the Invention Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. A term "mobile terminal" used herein refers to a device having a predetermined communication module (for example, a CDMA module) mounted therein for enabling mobile communication. The device may include terminals such as a PDA (Personal

Digital Assistant), a hand-held PC, a mobile phone and the like, in which a communication module is embedded or mounted. determination of Position of Mobile terminal> FIG. 1 is a block diagram illustrating a system for obtaining location information of a mobile terminal, which is used in a method for providing a navigation service by using location information of the mobile terminal according to the present invention. Referring to FIG. 1, the system for obtaining the location information of the mobile terminal, which is used in the method for providing the navigation service by using the location information of the mobile terminal according to the present invention, includes a mobile terminal 110, a base station 120, a home location register (hereinafter, referred to as "HLR") 130, a location-based service (hereinafter, referred to as "LBS") server 140 located on the part of a mobile network operator, and a location information server 150. As well known to those skilled in the art, to provide mobile communication services such as cellular and PCS, a service region is divided into predetermined cells wherein one or more base stations 120 are disposed in each cell. A mobile terminal 110 located in one cell makes predetermined communications with the base station 120 to perform processes such as synchronization and paging with the base station 120. Location information of the mobile terminal 110, which is obtained through the paging process with the base station 120, is recorded in the HLR 130. The location information of the mobile terminal 110, which is adopted in the method for providing the navigation service according to the present invention, may be obtained by the following methods: (1) A method of obtaining location information of the mobile terminal 110 using the LBS server 140. The mobile terminal 110 maintains base station parameters for a specific base station 120 therein, which are obtained through consistent communications with the base station 120. The mobile terminal 110 transmits such base station parameters to the location information server 150 via a mobile communication network. The location information server 150 sends the received base station parameters to the LBS server 140 located on the part of the mobile network operator. The LBS server 140 supplies location information (longitude and latitude information, address information, etc. of the base station 120) on the base station 120, which corresponds to the base station parameters, to the location information server 150 by using the received base station parameters. The location information server 150 sends the received location information on the base station 120 to the mobile terminal 110. (2) A method of obtaining location information of the mobile terminal 110 using a paging channel. As known to those skilled in the art, a paging channel is a channel for transferring additional information, messages on paging, commands, channel allocation, etc. for a specific mobile station to a mobile terminal within a given service region. The paging channel can support two transfer speeds, 9600bps and 4800bps. Information on this transfer speed is transferred via a synchronizing channel. For reference, the term "paging" is to determine whether a mobile terminal can receive an incoming call. This modulation process of the paging channel includes a similar modulation process, but may include a data scramble process using a paging channel long code mask. The mobile terminal .is synchronized with a base station through a pilot channel, receives a message of a synchronizing channel to be synchronized with a system and then continues to monitor the paging channel to determine whether the channel can receive a call toward itself. The mobile terminal 110 maintains base station parameters for a specific base station 120 therein, which are obtained through consistent communications with the base station 120. The location information server 150 requests that the mobile terminal 110 send the base station parameters, by using the paging channel. The mobile terminal 110 sends the base station parameters for the specific base station 120 where the mobile terminal 110 is located to the location information server 150 by using the paging channel. The location information server 150 transmits the received base station parameters to the LBS server 140 located on the part of the mobile network operator. The LBS server 140 supplies location information (longitude and latitude information, address information, etc. of the base station 120) on the base station 120, which corresponds to the base station parameters, to the location information server 150, by using the received base station parameters. The location information server 150 sends the received location information on the base station 120 to the mobile terminal 110. (3) A method for obtaining location information on the mobile terminal 110 if a

GPS receiving module is mounted in the mobile terminal 110. GPS signals are received through a GPS receiving module mounted in the mobile terminal 110. The mobile terminal 110 sends the received GPS signals to a mobile positioning center (hereinafter, referred to as "MPC") server (not shown) located within the location information server 150. The MPC server calculates location information on the mobile terminal 110 by using the received GPS signals and transmits the calculated location information to the mobile terminal 110. The location information on the mobile terminal 110, which is used in the method for providing the navigation service according to the present invention, can be obtained through the aforementioned methods. It will be apparent to those skilled in the art that location information on the mobile terminal 110 can be obtained through a variety of methods other than the described method. The location information on the mobile terminal 110, which is obtained using the above method or other methods, can be used in the method for providing the navigation service, which will be described later. <Embodiment 1> FIG. 2 is a flowchart illustrating steps of embodying a method for providing a navigation service using location information on a mobile terminal according to a first embodiment of the present invention. Referring to FIG. 2, the method for providing the navigation service using the location information of the mobile terminal according to the first embodiment of the present invention is performed as follows. A user applies power to a second terminal. According to a preferred embodiment of the present invention, this second terminal is a GPS receiver. A case where power is first applied or power is applied after power has been turned off corresponds to the aforementioned cold start or warm start state, respectively. In this case, in order to receive GPS signals, a predetermined standby time (several to 10 or more minutes) is required. Further, there may be a. case where reception of GPS signals is impossible due to a predetermined reason. This may happen when the user drives a car in downtown areas where buildings are crowded or in shadow zones where GPS signals do not reach. This is applied to when a user having a personal navigation system (PNS) is located in an area where the reception of GPS signals is impossible. As such, if it is impossible to search current location information using GPS signals, the steps shown in FIG. 2 may be performed. Location information on the first terminal is searched (S201). According to a preferred embodiment of the present invention, the first terminal is a mobile terminal. A method for searching the location information on the first terminal may be performed through the above three methods for obtaining location information. The location information of the first terminal obtained through the above method is input as source information of a navigation system (S202). More specifically, the source information input in step S202 is not an exact current location of the first terminal, but is location information on a base station within a cell where the first terminal is located. In step S202, the source information may be replaced by the current location information on the first terminal, as described above, and the user may directly input specific area information. The user inputs destination information to the navigation system (S203). The navigation system calculates predetermined path information based on source and destination information (S204). Calculated path information is provided to the user's first terminal (S205). The user drives the car according to the provided path information. It is determined whether the user' second terminal receives GPS signals (S206). If a predetermined standby time has elapsed after a cold start or warm start state, or a predetermined reason for preventing the reception of GPS signals has been removed, the second terminal can receive GPS signals. If it is determined that the second terminal is receiving the GPS signals, current location information of the user is calculated based on the received GPS signals (S207). The path information calculated in step S204 is corrected based on the calculated current location information and the destination information inputted in step S203 (S208) and the corrected path information is then again provided to the first terminal (S209). As the path information corrected in step S209 is provided to the first terminal, it is possible to correct errors in a path, which may occur due to differences between the source information (location information on the base station within the cell where the first terminal is located) input when the navigation service begins and information on a source where the user is actually located. In case of Seoul, one base station within a radius of 500m is usually located. Path information provided using location information on the base station within the cell where the mobile terminal is located at the early stage when the terminal does not receive GPS signals, can have a predetermined exactness. Since the GPS signals are received after the user has started driving their car, the exact current location of the user is determined and the path information is then corrected. Accordingly, rapid navigation service can be provided to the user. <Embodiment 2> FIG. 3a is a flowchart illustrating steps for embodying a method for providing a navigation service using location information on a mobile terminal according to a second embodiment of the present invention. Referring to FIG. 3a, a method for providing the navigation service using the location information of the mobile terminal according to the second embodiment of the present invention is performed as follows: A step of applying power to a second terminal is the same as that described with reference to the first embodiment of the present invention. In case of a warm start or cold start state or when the reception of GPS signals is impossible due to a predetermined cause, i.e. if current location information cannot be searched using GPS signals, steps shown in FIG. 3a may be carried out. Location information of a user's first terminal is searched (S301). According to a preferred embodiment of the present invention, the first terminal is a mobile terminal. The method for searching location information on the first terminal may be performed through the above three methods for obtaining location information. Location information of the first terminal obtained through the above methods is input as source information of a navigation system (S302). More specifically, the source information input in step S302 is not the exact current location of the first terminal, but location information of a base station within a cell where the first terminal is located. Similar to step S202 described with reference to FIG. 2, it is possible for the user to directly input specific location information as source information in step S302. The user inputs destination information to the navigation system (S303). The navigation system calculates first path information based on the source information and the destination information (S304). The calculated first path information is provided to the user's first terminal (S305). The user drives a car according to the provided path information. It is determined whether the user' second terminal receives GPS signals (S306).

If the predetermined standby time has elapsed after the cold start or warm start state or a predetermined cause that prevents the reception of GPS signals has been removed, the second terminal can receive GPS signals. If it is determined that the second terminal is receiving GPS signals, the user's current location information is calculated based on the received GPS signals (S307). Second path information from the current location to the source is calculated based on the calculated current location information and the destination information input in step S303 (S308). The path information calculated in step S308 is infoπnation on the path from the current location to the source, i.e. location where a base station is located. The path information from the base station (source) to the predetermined destination, which is calculated in step S304 when the navigation service begins, becomes first path information. After the reception of GPS signals, the path information from the user's current location to the source (location where the base station is located) becomes second path information. It is then determined whether the calculated second path information is a path that is advantageous to the first path information (S309). This is to determine whether new path information from the current location to the destination is advantageous by comparing the newly calculated second path information and the first path information, or whether it is advantageous to reach the destination along the first path information after moving from the current location to the source (base station). To determine whether it is an advantageous path in step S309, a variety of factors may be employed. Whether it is advantageous is determined based on whether the direction of movement is currently different from the calculated second path information or whether an expected moving distance from the current location to the destination is larger than the expected moving distance when the car is driven according to the second path information and first path information. If it is determined that the second path information is advantageous to the first path information in step S309, the second path information is provided to the first terminal (S310). If it is determined that the second path information is disadvantageous to the first path information in step S309, third path information from the current location calculated in step S307 to the destination input in step S303 is calculated (S311). The calculated third path information is provided to the first terminal (S312). FIG. 3b is a view showing an example that path information is recalculated in the method for providing the navigation service shown in FIG. 3a. Referring to FIG. 3b, a user begins at a source A. If the user does not receive

GPS signals due to a variety of reasons, the user sets the location of a base station A' as a source location according to the flowchart shown in FIG. 3 a and receives first path information up to a predetermined destination B. If the user can receive the GPS signals at a current location C, second path information from the current location C to the source A' is calculated according to the flowchart shown in FIG. 3 a. As shown in FIG. 3b, as the second path information (C->A') is disadvantageous to the first path information (A'->B), third path information from the current location C to the destination B is recalculated and is then provided to the user. Such third path information may be recalculated in a predetermined moving path search server connected via a predetermined communication network and may be transmitted to the user's first terminal. The path information may be recalculated in the user's first terminal. If the path information is recalculated in the moving path search server, the distance of the path to be searched is shortened. It is thus possible to reduce the data size of path information that is sent to the user's terminal. If the path information is recalculated in the user terminal, communications need not to be performed in order to receive the path information and rapid path research can be thus carried out. Through the above method, it is possible to correct path errors which may occur due to difference between source information (location information of the base station within the cell where the first terminal is located) input when the navigation service begins and information on a source where the user is actually located. <Embodiment 3> FIG. 4 is a flowchart illustrating steps for embodying a method for providing a navigation service using location information on a mobile terminal according to a third embodiment of the present invention. The method for providing the navigation service descried with reference to FIG. 4 is for providing the navigation service when GPS signals are not normally received such as when the power of a user' second terminal is off due to a predetermined cause, while the second terminal receives the GPS signals to manage normal navigation service. Referring to FIG. 4, a method for providing the navigation service using the location information on the mobile terminal according to the third embodiment of the present invention is performed as follows: Source information and destination information are first input to a navigation system (S401). At this time, a user's location information calculated based on received GPS signals and location information on a mobile termmal calculated according to the aforementioned methods might be input as source information. Predetermined path information is calculated based on the source and destination information input in step S401 (S402). The calculated path information is provided to the user's first terminal (S403). Current location of the user, which is calculated based on the received GPS signals, is stored in a predetermined memory means according to a predetermined period (S404). The predetermined period may be the same as a reception period of the GPS signals. The memory means may be a memory means embedded in the first terminal or may be a portable memory device such as a compact flash (CF) card, a SD card, a memory stick and so on, which can be attached to/detached from the first terminal. Furthermore, according to another embodiment of the present invention, the memory means having a user's current location stored therein is located at a central system that provides a navigation service. The user's current location may be transmitted to the first terminal via a mobile communication network, if necessary. It is determined whether the second terminal consistently receives GPS signals (S405). If it is determined that the second terminal consistently receives GPS signals, the process returns to step S404, in which the user's current location calculated using the received GPS signals is stored. If it is determined that the second terminal does not receive GPS signals due to a predetermined cause in step S405, information on the direction of movement is consistently displayed on the first terminal, based on the current location information stored in step S404, information on the direction of movement with regard to the path information, which is calculated based on the user's current moving angle information by means of a predetermined sensor means, and the like (S406). In step S406, the sensor means may be an earth magnetic sensor included in the first terminal or a dead reckoning (hereinafter, referred to as "DR") means embedded in the second terminal. Such an earth magnetic sensor senses the Earth's magnetism to detect the user's current direction of movement. Earth magnetic sensors have recently been embedded in mobile terminals (alias "Compass Chip") such as a mobile phones, etc. Furthermore, the DR means is a device that performs navigation using a gyroscope (or an earth magnetic sensor) and a speed sensor (or an acceleration sensor). The DR means can calculate the current location or direction of movement from the user's initial location. According to the aforementioned third embodiment of the present invention, even if the reception of GPS signals is not properly working while the user drives their car, information on the direction of movement can be consistently displayed on the user's first terminal. This allows a navigation service to be smoothly, continuously provided. <Embodiment 4> FIG. 5 is a flowchart illustrating steps for embodying a method for providing a navigation service using location information on a mobile termmal according to a fourth embodiment of the present invention. The method for providing the navigation service described with reference to FIG. 5 is for providing navigation services if a user begins driving a car after the user stops the car for a short time or for a long time due to various causes while the user drives the car. Referring to FIG. 5, the method for providing the navigation service using the location information of the mobile terminal according to the fourth embodiment of the present invention is performed as follows: Source information and destination information are first input to a navigation system (S501). At this time, a user's location information calculated based on received GPS signals or location information on the mobile terminal calculated according to the aforementioned methods might be input as source information. Predetermined path information is calculated based on the source and destination information input in step S501 (S502). The calculated path information is provided to the user's first terminal (S503). The user's current location calculated based on the received GPS signals and the path information calculated in step S502 are stored in a predetermined memory means (S504). As described with reference to FIG. 4, the memory means may be a memory means embedded in the first terminal and may be a portable memory device such as a compact flash (CF) card, a SD card, a memory stick and so on, which can be attached to/detached from the first terminal. Furthermore, according to another embodiment of the present invention, the memory means having a user's current location stored therein is located at a central system that provides a navigation service. Further, the current location and the path information may be transmitted to the first terminal via a mobile communication network, if needed. If the user begins driving their car after the user stops the car for a short time or for a long time and connects the first terminal to a predetermined navigation set while separating the first terminal from the predetermined navigation set, a list of current location information and path information stored in step S504 is displayed on the user's first terminal (S505). The user inputs a predetermined acknowledgement response if it is determined that the stored list of the current location information and path information is identical to that of the location information and path information before the car is stopped for a short time or parked for a long time (S506). The current location information and path information stored corresponding to the user's acknowledgement response are provided to the first terminal (S507). According to the fourth embodiment of the present invention, if the user resumes driving the car after the car is temporarily stopped or parked due to a variety of reasons, a series of processes for applying power to the GPS receiver or obtaining the user's current location information to calculate predetermined path information may be omitted. Therefore, it is possible to not only provide rapid navigation service but also reduce unnecessary communication fees, etc. consumed in order to newly receive path information, etc. <Embodiment 5> FIG. 6a is a flowchart illustrating steps for embodying a method for providing a navigation service using location information of a mobile terminal according to a fifth embodiment of the present invention. The method for providing the navigation service described with reference to FIG. 6a is for providing path information to a user's first terminal if the user selects path information, which has been already used by the user and stored in a predetermined memory means, in order to receive a navigation service. Referring to FIG. 6a, the method for providing the navigation service using the location information of the mobile terminal according to the fifth embodiment of the present invention is performed as follows: Information on one or more paths that have already used by a user is stored in a predetermined memory means (S601). As described above, the memory means may be a memory means embedded in a first terminal and may be a portable memory device such as a compact flash (CF) card, a SD card, a memory stick and so on, which can be attached to/detached from the first terminal. Further, according to another embodiment of the present invention, the memory means having a user's current location stored therein is located at a central system that provides a navigation service. The path information may be transmitted to the first terminal via a mobile communication network, as needed. If the user wants to use the navigation service, a list of path information stored in the memory means is displayed on a display means of the user's first terminal (S602). The user determines whether there is path information among the list along which the user wants to move and then selects/inputs predetermined path information (S603). In response to the input of the user, the predetermined path information stored in the memory means is provided to the first terminal (S604). Therefore, the user can drive the car along the path information. FIG. 6b is a view showing an exemplary screen displayed on a user's mobile terminal in the method for providing the navigation service described with reference to FIG. 6a. If a user selects an item "Guide Recent Road" from a predetermined user interface screen (a) at the same time when a navigation service begins, a list of path information that has recently been used by the user is displayed (b). Then, the user selects an item for a path to use from the displayed list. Predetermined path information corresponding to the selected item is then provided to the first terminal. According to the fifth embodiment of the navigation service of the present invention described with reference to FIG. 6a and FIG. 6b, a series of processes for obtaining a user's current location information for path information that has been used by the user and calculating predetermined path information again may be omitted. Accordingly, it is possible to not only provide rapid navigation service but also reduce unnecessary communication fees, etc. consumed in order to newly receive path information, etc. Furthermore, the present invention provides a computer-readable recording medium in which a program for implementing a method for providing a navigation service using location information on a mobile terminal according to respective embodiments of the present invention is recorded. The computer-readable recording medium may contain program instructions, data files, data structures, or a combination thereof. The program instructions may be ones that are specially designed or written for the present invention or may be ones that are well known to those skilled in the field of computer software. For example, the computer-readable recording medium includes a magnetic medium such as a hard disk, a floppy disk and a magnetic tape, an optical medium such as CD-ROM and DND, a magneto-optical medium such as a floptical disk, and hardware devices such as read only memory (ROM), random access memory (RAM) and flash memory that are specially configured to store and execute the program instructions. The medium may be a transfer medium such as an optical or metal line and waveguide, including a carrier wave that transmits signals for specifying the program instructions, data structures and the like. Examples of the program instructions may include high-level language codes executable by a computer using an interpreter as well as machine language codes such as those written by a compiler.

Industrial Applicability According to a method for providing a navigation service using location information on a mobile terminal, the present invention has an effect that it can provide predetermined path information to a user by using location information on a mobile terminal of the user without a predetermined standby time even if a GPS receiver is in a cold start or warm start state. Furthermore, according to a method for providing a navigation service using location information on a mobile terminal, the present invention has an effect that it can provide a user with predetermined path information by using location information of a mobile terminal of the user even when a GPS receiver mounted into a car does not work well due to a number of given problems. Furthermore, according to a method for providing a navigation service using location information on a mobile terminal, the present invention has an effect that it can provide a user with predetermined path information by using location information of a mobile terminal of the user even when the user is located at a region where the user cannot receive GPS signals via a personal navigation system. Furthermore, according to a method for providing a navigation service using location information on a mobile terminal, the present invention has an effect that it can minimize unnecessary communication fees or standby time by allowing a navigation service to be made using previously provided path information and map data even though a user resumes driving a car after the user stops the car for a short time while using the navigation service or after the user did not use the car for a long time. Furthermore, according to a method for providing a navigation service using location information on a mobile terminal, the present invention has an effect that it can minimize unnecessary communication fees and standby time, which are produced due to the reception of additional path information and map data, by allowing recently used path information to be stored and the stored path information to be provided to the user at the request of the user. The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Claims

1. A method for providing a navigation service, comprising the steps of: searching location information of a user's first terminal; receiving the searched location information on the first terminal as source information; receiving predetermined destination information; calculating predetermined path information based on the source information and destination information; providing the calculated path information to the user's first terminal; determining whether a user's second terminal can receive GPS signals; correcting the path infoπnation on the basis of the user's location information calculated based on the GPS signals, when the second terminal can receive the GPS signals; and providing the corrected path information to the first terminal.

2. A method for providing a navigation service, comprising the steps of: searching location information of a user's first terminal; receiving the searched location information on the first terminal as source information; receiving predetermined destination information; calculating first path information based on the source information and destination information; providing the calculated first path information to the user's first terminal; determining whether a user's second terminal can receive GPS signals; calculating the user's current location by analyzing the GPS signals, when the second terminal can receive the GPS signals; calculating second path information from the calculated current location to the source; and providing the second path information to the first terminal.

3. The method as claimed in claim 2, wherein the step of calculating the second path information comprises the steps of: determining whether the calculated second path is currently advantageous to the first path; and calculating a third path from the calculated current location to the destination when it is determined that the calculated second path is disadvantageous to the first path, wherein the step of providing the second path information includes providing the third path information instead of the second path information to the first terminal.

4. A method for providing a navigation service, comprising the steps of: receiving predetermined source information; receiving predetermined destination information; calculating predetermined path information based on the input source information and the input destination information; providing the calculated path information to a user's first terminal; controlling current location information of the user to be stored in a predetermined memory means; determining whether a user's second terminal consistently receives GPS signals; and when it is determined that the user's second terminal does not consistently receive GPS signals, providing to the first terminal the stored current location information of the user and moving direction information on the path information, which is calculated using current moving angle information of the user from a predetermined sensor means.

5. The method as claimed in claim 4, wherein the sensor means is an earth magnetic sensor included in the first terminal or a DR(Dead Reckoning) means included in the second terminal.

6. A method for providing a navigation service, comprising the steps of: receiving predetermined source information; receiving predetermined destination information; calculating predetermined path information based on the input source information and the input destination information; providing the calculated path information to a user's first terminal; controlling current location information of the user and the path information to be stored in a predetermined memory means; providing the stored current location information and the path information to the first terminal; receiving an acknowledge response for the stored current location information and the path information from the user; and providing the current location information and the path information to the user's first terminal.

7. A method for providing a navigation service, comprising the steps of: controlling predetermined path information to be stored in a predetermined memory means; controlling one or more said path information stored in the memory means to be displayed on a user's first terminal; selectively receiving one of one or more said path information displayed on the first terminal from the user; and providing the received path information to the first terminal.

8. The method as claimed in claim 1 or 2, wherein the step of searching the location information of the user's first terminal comprises the steps of: receiving predetermined base station parameters stored in the first terminal; transmitting the received base station parameters to a location-based service

(LBS) server; receiving location information of a base station corresponding to the base station parameters from the LBS server; and providing the received location information of the base station to the first terminal.

9. The method as claimed in claim 1 or 2, wherein the step of searching the location information of the user's first terminal comprises the steps of: requesting the first terminal to transmit predetermined base station parameters stored in the first terminal through a predetermined paging channel; receiving the base station parameters from the first terminal through the paging channel; transmitting the received base station parameters to a location-based service (LBS) server; receiving location information of a base station corresponding to the base station parameters from the LBS server; and providing the received location information of the base station to the first terminal.

10. The method as claimed in any one of claims 1 to 4, wherein the first terminal is a mobile terminal and the second terminal is a GPS receiver.

11. The method as claimed in any one of claims 1 to 4, wherein the first terminal is a mobile terminal and the second terminal is a GPS receiving module built in the first terminal.

12. The method as claimed in claim 6 or 7, wherein the first terminal is a mobile terminal.

13. The method as claimed in any one of claims 4 to 7, wherein the memory means is a built-in type memory means embedded in the first terminal or a portable type memory means which can be attached to/detached from the first terminal.

14. The method as claimed in any one of claims 4 to 7, wherein the memory means is located at a predetermined navigation service providing system and communicates with the first terminal via a mobile communication network.

15. A computer-readable recording medium in which a program for implementing a method according to any one of claims 1 to 7 is recorded.