The present invention relates to a method and a system for monitoring performance pertinent to a position determination of a mobile communication terminal, and more particularly to a method and system for monitoring performance pertinent to position determination of a mobile communication terminal by using various parameters defined in IS(Interim Standard)-801-1 in determining position of a mobile communication terminal in wireless/mobile communication network environment using an A-GPS scheme.
Many companies are struggling to develop new wireless Internet technologies which can be used to provide various communication services, such as wireless Internet services, regardless of places. Wireless Internet refers to an environment or technology which allows a moving user to access the Internet through a wireless network. With the development of mobile communication technologies and the explosive increase in the use of mobile phones, the wireless Internet services have also been greatly developed.
Among a variety of wireless Internet services provided to mobile terminals, such as cellular phones, PDAs or notebook computers, a LBS(Location Based Service) is being popularized more and more due to its wide applications and availability. The LBS can be used in various applications and conditions, such as emergency assistance, criminal tracking, GIS (Geographic Information System), difference of mobile communication fees according to locations, traffic information, vehicle navigation, logistics control and location-based CRM (Customer Relationship Management).
In order to exploit the LBS, it is required to identify the location of a mobile communication terminal. A GPS(Global Positioning System) is generally used to track the location of a mobile communication terminal.
The GPS is a worldwide navigation and positioning system which determines the location of an object on earth by using 24 GPS satellites orbiting the earth at an elevation of approximately 20,000 km. The GPS uses radio waves in a bandwidth of 1.5 GHz. Ground control stations which monitor the GPS satellites receive information transmitted from the satellites and synchronize transmission time. Users can monitor their locations by using GPS receivers. Generally, the GPS determines the location of an object by triangulation using four satellites. Three satellites are used for accurate triangulation, and a fourth satellite is in orbit to correct a timing error.
To be more specific, in the GPS system, since position of 3 satellites are already known, a position fix is performed by measuring distance between the satellites and a GPS receiver. The distance between the satellites and the GPS receiver can be obtained by multiplying the light speed by a wave propagation time between the satellite and the GPS receiver, in which the wave propagation time can be obtained by calculating time difference between the transmission time at the satellite and the reception time at the GPS receiver equipped with an internal clock.
In the meantime, the GPS has numerous advantages that, among others, it is open to anyone in the world, there is no constraint in the number of users, both a real-time position fix and a continuous tracking are possible and accuracy of position fix thereof is rather high enough for various applications.
However, it is difficult to determine the location of an object in downtown areas surrounded by high-rise buildings due to so-called multi-path effects and the lack of visible satellites. Also, an accurate location determination can hardly be made in a tunnel, subway or in a basement of a building where satellites are. not visible (where radio waves cannot reach). In addition, GPS receivers may require a TTFF (Time To First Fix) of several minutes to over ten minutes to initially determine their location, thereby causing inconvenience to the users of location-based wireless Internet services.
A-GPS answers some of the inherent problems with GPS. The A-GPS determines the location of a mobile communication terminal by combining GPS with wireless communication network resources. A mobile communication terminal collects geolocation information from both the GPS satellites and the wireless communication network to determine its 3-dimensional location in geodetic coordinates (latitude, longitude and altitude) with high accuracy. The wireless network and the mobile communication terminal transmit and receive data or messages containing parameters defined in IS(Interim Standard)-801-1.
Meanwhile, performance evaluation of the position determination in the position determination system for a mobile communication terminal is crucial to the communication network operator. Current performance evaluation in the A-GPS scheme, however, currently stays at the level of simply monitoring call flow messages defined in the IS-801-1 displayed on the monitor screen of a laptop computer. This bears such shortcomings that it cannot identify reasons for poor position fix performance while it only find the fact that normal position fix is suffering. In other words, the conventional position determination system cannot identify whether the poor position determination performance stems from the devices employed in the wireless communication network, from defects in the mobile communication terminal or from topography(for instance, high-rise building, mountain, trees, etc.), thereby hinders taking prompt measures thereto.
Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and an object of the present invention is to provide a method and system for monitoring performance pertinent to position determination of a mobile communication terminal by using various parameters defined in IS(Interim Standard)-801-1 in determining position of a mobile communication terminal in wireless/mobile communication network environment using an A-GPS scheme.
In order to accomplish this object, there is provided a system for monitoring performance of a position determination of a mobile communication terminal by using a wireless network and an A(Assisted)-GPS, the system comprising: the mobile communication terminal equipped with a GPS module for picking up GPS radio wave containing a navigation data from a GPS satellite and transmitting the navigation data to the wireless network; a test device, connected to the mobile communication terminal through wired/radio link, for being loaded with and running a LBS wireless network analysis program, wherein the LBS wireless network analysis program gathers, analyzes and processes data pertinent to the position determination and classifies processed data by at least one classification reference and displays classified data in the format of text or graph; and a position determination server for receiving the navigation data from the wireless network, converting the navigation data into longitude and latitude coordinate values, transmitting the longitude and latitude coordinate values to the mobile communication terminal and performs transmission and reception of the data pertinent to the position determination.
In accordance with another aspect of the present invention, there is provided a method for monitoring performance of position determination of a mobile communication terminal in a communication system including a mobile communication terminal picking up GPS radio wave and receiving LBS messages, a test device communicating with the mobile communication terminal and a position determination server performs transmission and reception of the LBS messages, the method comprising the steps of:(a) receiving the LBS messages on a real time basis from the mobile communication terminal; (b) analyzing received LBS messages on a real time basis; and (c) processing analyzed LBS messages into a requested format and displaying converted LBS messages in the format of text or graph.
In accordance with yet another aspect of the present invention, there is provided a computer readable storage medium storing a LBS(Location Based Service) wireless network analysis program receiving, analyzing, processing and displaying LBS messages defined in IP-801-1 standard by using a wireless network and an A(Assisted)-GPS(Global Positioning System), wherein the LBS wireless network analysis program, coded in a computer language, performs analyzing the LBS messages, displays analyzed LBS messages, and processes and displays information on the wireless network, information on GPS satellite and measured coordinate values included in the LBS messages in text and/or image format.
The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
Hereinafter, a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the drawings, the same element, although depicted in different drawings, will be designated by the same reference numeral or character. Also, in the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.
The monitoring system 100 in accordance with the present invention includes a mobile communication terminal 110, a test device 120, a radio base station 130, a mobile switching center 140, a STP 150, a LBS system 160 and a LBS platform 170.
The mobile communication terminal 110 which is equipped with a GPS antenna, a GPS receiver, a GPS chip set, etc., to thereby pick up GPS radio wave broadcast from orbiting GPS satellites(not shown), extracts navigation data from the GPS radio wave and transmits the navigation data to the LBS system 160.
The mobile communication terminal 110 can be a PDA(Personal digital Assistant), a cellular phone, a PCS(Personal Communication Service) phone, a hand-held PC, a GSM(Global System for Mobile) phone, a W-CDMA phone, an EV-DO phone, a MBS(Mobile Broadband System) phone, a WLL(Wireless Local Loop) phone and a digital TRS(Trunked Radio System) phone. Herein, the MBS phone refers to a mobile phone which will be used in fourth-generation communication systems.
The test device 120 procures various parameters defined in the IS-801-1 standard in relation to the position fix from the mobile communication terminal 110 through wired and/or radio link, analyzes and processes the parameters, and display the result of the analysis and the process. Herein, the radio communication refers to, but not limited to, an infra-red communication, a bluetooth communication or a RF(Radio Frequency) communication. The test device 120 is loaded with a built-in LBS wireless network analysis program for performing analysis on the performance of the position determination and providing display of analysis results by using the parameters defined the IS-801-1 standard in accordance with the present invention.
The LBS wireless network analysis program in accordance with the present invention procures the LBS messages defined in the IS-801-1 standard which the mobile communication terminal 110 collects from a position determination server 162, performs analysis on the LBS messages and displays analysis results. In addition, the LBS wireless network analysis program displays information on the wireless network to which the mobile communication terminal 110 is being currently connected, a pseudo random noise code of a radio base station which gathers and transmits the LBS messages from the position determination server 162 and the strength of the pseudo random noise code.
The mobile communication network in accordance with the present invention can be a CDMA(Code Division multiple Access), GSM(Global system for Mobile communication), CDMA2000 1X, 3X, EV-DO, EV-DV, WCDMA(Wideband CDMA), PI(Portable Internet), WLL(Wireless Local Loop) and Digital TRS(Trunked Radio System).
The radio base station 130, housed with a BTS(Base station Transceiver System) 132 and a BSC(Base Station Controller) 134, performs functions such as processing call request from the mobile communication terminal 110 and relaying the parameter messages defined IS-801-1 standard communicated between the mobile communication terminal 110 and the LBS system 160.
The base station transceiver system 132 is a network endpoint equipment generally performing a base band signal processing, wired/radio conversion, transmission and reception of wireless signal, and especially in the preferred embodiment, performs communication with the test device 120 via the mobile communication terminal 110.
The base station controller 134 which performs comprehensive control over the base station transceiver system 132 performs various functions such as a radio channel allocation and release with respect to the mobile communication terminal 110, transmission power control of the test device 120 and the base station transceiver system 132, decision of soft handoff or hard handoff, transcoding and vocoding, GPS clock distribution, operation and maintenance of the base station transceiver system 132.
The mobile switching center 140 controls the radio base station to more effectively operate and communicate with an electronic switching system installed in a public telephone network. The mobile switching center 140 receives data or messages from the mobile communication terminal 110 through the radio base station 130 and transfers the received data or messages to the position determination server 162.
The signal transfer point (STP) 150 is a signal relay station for relaying and exchanging signal messages in a common channel signaling system of ITU-T. A signal network formed using the STP 150 operates in a non-associated mode which does not associate a speech path with a signal path. Various signals are transferred via the STP 150 having a speech path, other than a switching center, thereby improving reliability and cost-effectiveness. Also, the STP 150 converts a signal message. When it is not possible to relay a signal message, the STP 150 notifies the signal message to another switching center.
The LBS system 160 includes a position determination server 162 and a MPC(Mobile Positioning Center) 164. The position determination server 162 calculates longitude and latitude coordinate values by using the navigation data received from the mobile communication terminal 110 through the wireless network. Further, the position determination server 162 transmits an aiding data for use in the position determination of the mobile communication terminal 110 and calculates distance between the GPS satellite and the mobile communication terminal 110. Herein, the aiding data is transmitted according to the TCP/IP protocol.
The mobile positioning center 164 obtains the longitude and latitude coordinate values of the mobile communication terminal 110 calculated at the position determination server 162 and transmits the coordinate values to the LBS platforms 170 that provides various location based services.
The LBS platform 170 comprehensively refers to an application server for providing the location based services for the mobile communication terminal 110. The LBS platform 170 obtains the longitude and latitude coordinate values of the mobile communication terminal 110, performs coordinate conversion and the like, and finally provides the location based services. The data exchange between the position determination server 162 or the position center 164 and the LBS platform 170 is executed based on the TCP/IP protocol.
Referring to the exemplary screen of
Kinds of messages analyzed and displayed by the LBS wireless network analysis program in accordance with the present invention are, as shown in
The LBS wireless network analysis program classifies the LBS messages as forward channel messages versus reverse channel messages and distinctively displays the classified LBS messages, wherein the forward channel messages refer to LBS messages transmitted from the position determination server 162 toward the mobile communication terminal 110 whereas the reverse channel messages refer to LBS messages transmitted from the mobile communication terminal 110 toward the position determination server 162. Also the LBS wireless network analysis program classifies the LBS messages according to time of transmission or reception or according to a message type, e.g., a request type(Req_Type) and a response type(Resp_Type) to display distinctively each classified messages.
Turning back to
Herein, the message “Provide MS Information” is well known from the IS-801-1 standard as such will not be discussed in great detail.
Description will now be given in conjunction with
Meanwhile, the LBS wireless network analysis program indicates with a certain color the information of the GPS satellite(identification number of the GPS satellite) which the position determination server 162 provides for the mobile communication terminal 110 and extracts information on the GPS satellite that the mobile communication terminal 110 perceived from the “Provide Pseudorange Measurement” message. Next, the LBS wireless network analysis program indicates the GPS satellite that the mobile communication terminal 110 perceived on the same screen but with a different color to thereby enable the user to acquire knowledge on which satellite the mobile communication terminal 110 perceives in true test environment.
Turning back to
In the concentric circles of
The LBS wireless network analysis program renders the screen to display a C/No(Carrier to Noise) or the strength of the GPS radio wave transmitted from each GPS satellite that the mobile communication terminal 110 actually gained acquisition along with the relevant identification number of the GPS satellite. Herein the C/No is a value presenting a reception sensitivity of the GPS radio wave broadcast from each GPS satellite. In other words, the C/No is a signal to noise ratio at 1 Hz bandwidth and is an important indicator in evaluation of capability of a GPS receiver. The larger the C/No value is the better the mobile communication terminal 110 receives GPS radio wave. The LBS wireless network analysis program, as shown in lower part of
Describing in conjunction with
Herein, the electronic map data stored in the test device 120 has been made in WGS(World Geodetic System)-84 format. The map can also display concentric circles centering at a specific location with an interval of e.g., 50 meters as well as 4 directional intersections. In addition, the LBS wireless network analysis program is capable of zooming in or zooming out the map by the, reference of the concentric circles or the 4 directional intersections and displaying the map zoomed in or zoomed out.
The LBS wireless network analysis program extracts the longitude and latitude values of the mobile communication terminal 110 contained in the “Provide Location Response” message which has been received from the position determination server 162 and displays the position of the mobile communication terminal on the map.
To be more specific, the LBS wireless network analysis program displays some area of the map around the coordinate values of the true position of the mobile communication terminal 110. Herein, the coordinate values of the true position can be determined as an average value of the measured positions (longitude and latitude values). At least one concentric circles having different radius each center of which is the coordinate values of the true position are displayed. For instance, the radius of the concentric circles may be 10 m, 20 m, 30 m, 50 m, 100 m, 150 m and the like.
Next, the LBS wireless network analysis program extracts the longitude and latitude values from the “Provide Location Response” message received from the mobile communication terminal 110 and displays the longitude and latitude values on the map. In case the positions of the mobile communication terminal 110 are consecutively determined, the measured position values are sequentially indicated on the map. Therefore, the measured values consecutively measured are indicated in each concentric circle as shown in
In the meantime, the LBS wireless network analysis program in accordance with the present invention supports both a fixed reference mode and a moving reference mode. The fixed reference mode refers to a map display method that the measured position is analyzed and indicated while the position of the mobile communication terminal 110 is fixed at a certain point, while the moving reference mode refers to another map display method that the measured position is analyzed and indicated while the position of the mobile communication terminal 110 is moving about on the map. In case of the moving reference mode, the real time measured position of the mobile communication terminal 110 are set to be always located at the center of the map so that the map is made shifting according to the movement of the position of the mobile communication terminal 110.
The horizontal axis(x-axis) represents a measurement sequence and the vertical axis(y-axis) represents a position error between the true position and the measured position. The position errors associated with the measurement sequence are indicated as dots on a real time basis and each neighboring dot is consecutively connected with a line so that the trend of the distant errors may be easily read.
The LBS wireless network analysis program estimates and displays the number of total measurements; the number of measurements having position error whose radius is less than each of 10 m, 20 m, 30 m, 50 m, 100 m, 150 m, respectively; and/or the number of measurements having position error within up to 67% or 95% counting from the least position error among the total measured points. Referring to
Certainly, the scale or range of the position errors can vary. In addition to the above, the LBS wireless network analysis program is capable of calculating and displaying a so-called “bias east” or “bias north”, wherein the bias east may be an average horizontal component of the position errors accumulated up to a certain time and the bias north may be an average vertical component of the position errors accumulated up to the certain time.
Meanwhile, the LBS wireless network analysis program in accordance with the present invention can be stored in a computer-readable storage medium, wherein the storage medium can be any one out of a floppy disc, a hard disc, a ZIP disc, a JAZ disc, a compact disc, a DVD(Digital Versatile Disc).
Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
As described above, evaluation of the position determination performance can be promptly and effectively performed by using the method and system in accordance with the present invention.
In addition, the wireless network operator can provide higher quality location based services to the users since the method and system in accordance with the present invention provide prompt identification of the reasons for failure of the position determination when the position determination suffers.
Number | Date | Country | Kind |
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10-2003-0007036 | Feb 2003 | KR | national |
10-2004-0006781 | Feb 2004 | KR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/KR04/00198 | 2/4/2004 | WO | 5/16/2006 |