KR100940220B1 - Method for adjusting time interval of transmitting positioning information and system employing the same - Google Patents

Abstract

In a system in which a wireless terminal and a server communicate location information to estimate and / or determine a location of a wireless terminal, a method of changing a location information transmission period for reducing the amount of computation and improving an operation speed by changing the transmission period of the location information and the same The system used is disclosed. The method of changing a location information transmission period may include obtaining first information which is information related to a location of a wireless terminal, calculating a difference between the first information and second information which is information related to a location of a wireless terminal previously obtained; Determining that the first information is meaningless when the difference is less than a predetermined threshold, and changing the location information transmission period based on the determination result. The efficiency of the system can be improved by adjusting the transmission period based on the significance of the information.

Location information transmission, change of frequency, significance

Description

How to change the location information transmission cycle and system using the same {METHOD FOR ADJUSTING TIME INTERVAL OF TRANSMITTING POSITIONING INFORMATION AND SYSTEM EMPLOYING THE SAME}

The present invention relates to a method for changing a location information transmission period and a system using the same, and more particularly, a system in which a wireless terminal and a server communicate location information to estimate and / or determine a location of the wireless terminal (hereinafter, referred to as a 'location tracking system'). The present invention relates to a method for changing a location information transmission period for reducing the amount of computation of the system and improving an operation speed by changing the transmission period of the location information.

The location tracking system generally includes a server including a location determination engine and a wireless terminal for transmitting location information, the wireless terminal transmitting location information to the server and the server based on the received location information. Calculate the position of. The location tracking system may further include an access point to relay communication between the server and the wireless terminal or to provide a separate signal to the wireless terminal.

The location tracking system can be largely divided into an infrastructure-based architecture and a terminal-based architecture. In the infrastructure-based scheme, the wireless terminal periodically broadcasts its location information and the server receiving the location information determines the location of the wireless terminal. On the other hand, in the terminal-based scheme, the access point periodically broadcasts a beacon signal, and the wireless terminal that receives the signal transmits the location information to the server. In this case, the wireless terminal may directly estimate its location and provide it to the server.

As described above, in the wireless location tracking system, the wireless terminal periodically transmits location information to the server, and the server must process it. However, when the number of wireless terminals is increased, the amount of location information received by the server is greatly increased, and in order to process this, the server has to perform very many operations. This reduces the operating speed of the system and lowers the accuracy of the position estimate. In addition, since the wireless terminal must continuously transmit the location information regardless of the location change, power consumption increases and inconvenience in using the terminal is caused.

In order to solve this problem, it is proposed to use a server device with a large processing capacity or to use a parallel server composed of multiple servers, but this increases the system construction cost and is not only impractical, but also reduces the power consumption of the terminal. It doesn't help

SUMMARY OF THE INVENTION The present invention has been made in view of the above object, and an object of the present invention is to dynamically change the location information transmission period in a location tracking system, thereby reducing the amount of computation of the system and improving operation speed and power efficiency.

According to an aspect of the present invention for achieving the above object, the step of acquiring first information which is information related to the position of the wireless terminal, the second information which is information relating to the first information and the position of the previously obtained wireless terminal; Calculating a difference between the two, determining the first information as meaningless when the difference is less than a predetermined threshold, and changing the location information transmission period based on the determination result. This is provided.

Preferably, the first information and the second information include location information of the wireless terminal. In addition, the determining may preferably take into account information about acceleration of the wireless terminal. The changing may include changing the period when it is determined that the first information is meaningless more than a threshold number of times in succession.

Advantageously, acquiring said first information comprises receiving said first information, and said modifying comprises requesting a change in said period. Alternatively, the acquiring of the first information may be performed by generating the first information.

According to another aspect of the present invention, there is provided a method of changing a location information transmission period comprising determining a location of a wireless terminal and changing a location information transmission period when the location corresponds to a predetermined zone.

In the determining of the location, it is preferable that the RFID (Radio Frequency Identification) reader installed in the predetermined area determines the location based on the read information of the RFID tag installed in the wireless terminal.

On the other hand, the changing step may block the transmission of the location information for a predetermined time. In addition, the changing may block the transmission of the location information until it is determined that the location of the wireless terminal is out of the predetermined area. In the changing, the RFID reader installed in the predetermined zone may determine whether the position of the wireless terminal is out of the predetermined zone based on the information obtained by reading the RFID tag installed in the wireless terminal.

According to still another aspect of the present invention, in the method for changing the location information transmission period in a wireless terminal transmitting location information at a predetermined period, the location information transmission period is changed, wherein the location information transmission period is changed based on a communication time. A method is provided.

According to another aspect of the present invention, a method for changing the location information transmission period in a server that receives location information from a wireless terminal at a predetermined period and calculates a location, comprising: changing the location information transmission period based on a communication time A method of changing a location information transmission cycle is provided.

According to another aspect of the present invention, there is provided a computer readable recording medium having recorded thereon a program for causing the method to be executed on a computer.

According to another aspect of the present invention, in a wireless terminal for transmitting location information to a server, location information obtaining means for obtaining first information which is information related to a location of the wireless terminal, the first information and the previously obtained wireless terminal. A significance determination means for calculating a difference between the second information, which is information related to the location of, and determining the first information as meaningless when the difference is less than a predetermined threshold, and a transmission period of the location information based on the determination result. A wireless terminal is provided which includes a period changing means for changing.

According to another aspect of the present invention, there is provided a wireless terminal which periodically transmits position information to a server, comprising period changing means for changing the position information transmission period based on a communication time.

According to still another aspect of the present invention, there is provided a server for receiving location information from a wireless terminal, comprising: location information obtaining means for obtaining first information which is information related to a location of a wireless terminal, the first information and previously obtained wireless Significance determination means for calculating a difference between the second information, which is information related to the location of the terminal, and determining the first information as meaningless when the difference is less than a predetermined threshold, and a transmission period of the location information based on the determination result A server is provided that includes a period changing means for requesting to change.

According to another aspect of the present invention, there is provided a server for receiving location information from a wireless terminal, comprising: positioning means for determining a location of the wireless terminal, and changing the location information transmission period when the location corresponds to a predetermined area; A server is provided that includes requesting period changing means.

According to another aspect of the present invention, there is provided a server, which periodically receives location information from a wireless terminal, comprising period changing means for requesting to change the location information transmission period based on a communication time.

According to the present invention, in the location tracking system, the location information transmission period may be dynamically changed to reduce the amount of computation of the system and to improve operation speed and power efficiency.

Hereinafter, with reference to the accompanying drawings will be described a specific embodiment of the present invention, but this is only an example and the present invention is not limited thereto. In the following description, the terms "transfer", "communication", "transmit", "receive" and other similar meanings of signals or information are not only meant to directly convey the signal or information from one component to another. It also includes passing through other components. In particular, "transmitting" or "sending" a signal or information to a component indicates the final destination of the signal or information and does not mean a direct destination. The same is true for the "reception" of a signal or information. In addition, in this specification, "relating" two or more pieces of data or information means that if one piece of data (or information) is obtained, at least a portion of the other data (or information) can be obtained based thereon.

1 is a flowchart illustrating a principle of a method for changing a location information transmission period according to an embodiment of the present invention. The method of the present embodiment basically improves system efficiency by judging the significance of the positional information and adjusting the positional information transmission period to transmit only the meaningful information.

Specifically, the method begins by first obtaining first information that is information related to the location of the wireless terminal (step 110). Location-related information may be generated at the wireless terminal or at the server. When generating in the wireless terminal, it is also possible to generate location information from the beacon signal received from the access point.

Location-related information may include received signal strength (RSS), time of arrival (TOA), time of flight (TOF), time of arrival (TDOA) for signals transmitted by wireless mobile devices. It may include at least one of Time Difference Of Arrival, Angle Of Arrival, and Phase of Arrival.

In a next step 120, the difference [Delta] P between the first information and the second information which is information relating to the position of the previously obtained wireless terminal is calculated. The calculation of the difference can be implemented by simple subtraction. ΔP calculated in step 130 is compared with a predetermined threshold P _th . The threshold value may be appropriately determined according to the configuration of the system. If the threshold value is excessively large, the accuracy of the location information estimation becomes inferior, and if the threshold value is excessively small, the system load reduction effect is lost. Decisions should be made in consideration of these considerations.

On the other hand, the significance determination of this step may take into account the information on the acceleration of the wireless terminal. Since the acceleration of the wireless terminal is closely related to the change of the location of the wireless terminal, that is, the movement, it is possible to determine the necessity of updating the location information by including the information on the acceleration. In other words, the lower the necessity of updating the location information, the higher the meaninglessness of the location information. Therefore, the efficiency of the significance determination can be improved by additionally considering the information on the acceleration. The acceleration of the wireless terminal can be measured by an acceleration sensor inside the wireless terminal.

If the comparison result DELTA P is greater than or equal to the threshold in step 130, since there is a significant change in the location information, location estimation is performed based on this (step 190). At this time, the counter value C may be set to count the number of consecutive occurrences of the meaningless position information, and if it is determined that the position information is meaningful, the counter may be reset (step 140).

In addition, as described below, when the period is changed by a meaningless value received during the existing operation, the step may be initialized so that the period may be initialized and the position information may be transmitted again in the initial period (step 150). By setting a flag at the time of initializing the period, it is also possible to check whether the flag needs to be initialized by checking the flag value and to perform the period initialization accordingly.

On the other hand, when ΔP is less than the threshold, it is determined that the first information is meaningless. That is, there is no change in the position of the terminal or very small, so the need for updating the position information is low. It is possible to dismiss all location information that is considered insignificant or change the transmission cycle as soon as the meaningless location information is generated, but in reality, the meaninglessness of the location information may be determined by an error or a communication error on the system, thus meaningless location information a predetermined number of times. It is preferable to dismiss the location information or change the transmission period only when the PBs occur continuously. Therefore, for this purpose, the counter value is incremented by 1 in step 160 to count the number of continuous meaningless location information generation.

If it is determined in step 170 that the number of consecutive meaningless location information generations is equal to or greater than the predetermined threshold value C _th , the transmission period of the location information is changed (step 180). The change of the location information transmission period may be performed by a server or by a wireless terminal. In the case of the server, a period change request is made to the wireless terminal that substantially transmits the information. This can be implemented by changing the period flag value. In the case of the wireless terminal, it is possible to simply change the transmission period used in the internal circuit or request the access point to change the beacon signal transmission period.

The period change in this step 180 substantially extends the period, thereby reducing the number of location information transmissions and reducing the system load. It is also possible to extend the period indefinitely by changing the period. In this case, the location information transmission is substantially blocked.

According to another embodiment of the present invention, the change of the location information transmission period may be made based on the location of the wireless terminal, which will be described with reference to FIG. 2.

The method of FIG. 2 begins by first determining the location of a wireless terminal (step 210). Positioning may be performed by determining the coordinates of the wireless terminal by trigonometric, trilateral, fingerprinting, or a combination thereof. However, as will be described later, the method is sufficient to determine whether the wireless terminal belongs to a predetermined area, and thus it is not necessary to determine the absolute position of the wireless terminal. Therefore, it is sufficient to determine the relative position of the wireless terminal, and for example, an RFID (Radio Frequency Identification) system can be used.

Specifically, it is possible to determine whether the wireless terminal exists in the predetermined zone by installing an RFID tag in the wireless terminal and installing an RFID reader in the entrance, the exit, or the inside of the predetermined zone. In this case, the RFID reader transmits the read result to the server so that the server determines the position of the wireless terminal. Alternatively, an RFID tag may be installed at an entrance, an exit, or inside the zone, and the tag may be read through an RFID reader module included in the wireless terminal. In this way, the relative position may be directly determined by the wireless terminal.

In a next step 220, it is determined whether the location of the wireless terminal corresponds to a predetermined zone. The predetermined area means an area where the movement of the wireless terminal user is expected to be small. For example, areas such as toilets and meeting rooms tend to stay for a long time once the user enters. Therefore, when the terminal is located in these areas, the location information transmission period may be extended. For these zones, it is possible to determine whether the wireless terminal is located within the predetermined zone by comparing the prescribed zone with the location of the wireless terminal predefined and identified in the system. In the case of using the RFID method as described above, a special determination process is not required. However, in the case of using absolute coordinates, the coordinates of a designated area may be determined in advance in the system, and the present step may be performed based on this.

If it is determined in step 220 that the location of the wireless terminal is within a predetermined zone, the cycle is changed in step 230. However, if it is determined that it does not exist in the predetermined area, the location of the wireless terminal is continuously determined. In this manner, the system load can be reduced by extending the location information transmission period in an area where the location of the wireless terminal is not expected to change rapidly.

On the other hand, when the wireless terminal is out of the predetermined area, it is necessary to recover the cycle again. To this end, it is advantageous to use the RFID method described above. Using the RFID method, since the location of the wireless terminal can be determined without the communication between the wireless terminal and the server, the transmission can be resumed when the user leaves the area even if the location information is blocked in the predetermined area. On the other hand, in the case of using absolute coordinates, it is impossible to completely block communication between the wireless terminal and the server, and it is desirable to extend the period as much as possible.

In another embodiment of the present invention, the location information transmission period may be changed based on statistical information on the terminal location information change over time. The user of the wireless terminal exhibits a statistically constant movement characteristic over time. For example, the user's movement is active during the day, but movement is very limited at night. In addition, the shift is less during the working hours of about 2 to 5 o'clock, but the movement is active during the leave after 6 o'clock. Based on such statistical information, the system can extend the location information transmission period at a time when the user's movement is expected to be small.

Specifically, in the communication between the server and the wireless terminal, the communication time is grasped, and if the communication time is a time when the movement of the user is expected to be small, the location information transmission period is extended. On the other hand, when the user is expected to move actively, the location information transmission period may be shortened. On the other hand, the statistical information on the movement can be freely determined within the limits of the system capacity, such as daily, weekly, monthly, yearly.

The method described above may be embodied in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

In addition, this method may be performed in a wireless terminal or may be performed in a server. Hereinafter, an example of a wireless terminal and a server for executing the method will be described.

3 is a block diagram illustrating a wireless terminal according to an embodiment of the present invention.

The wireless terminal includes an RF transceiver 340 and an RF driver 330 for communicating with a server, which are controlled by the controller 310.

In addition, the wireless terminal includes a location information acquisition unit 360 to obtain information related to the location of the wireless terminal. For example, the location information acquisition unit 360 may perform location estimation to directly estimate the location of the wireless terminal. Alternatively, the location information acquisition unit 360 may generate information necessary for the server to perform location estimation.

The wireless terminal includes a significance determination unit 370 to determine the significance of the obtained information. The significance determination unit may compare the previous information with the current information to determine the significance of the information, and determine the number of consecutive occurrences of the meaningless information as needed. The determined information is provided through the control unit 310 or directly to the period changing unit 350 to perform the period change.

The period changing unit 350 changes the period of transmitting the location information to the server when the meaningless information occurs or when the meaningless information occurs continuously. In detail, the period changing unit 350 may request to change the location information transmission period of the wireless terminal itself or change the transmission period of the beacon signal transmitted from the access point.

The sensor unit 320 detects the acceleration of the wireless terminal and provides it to the significance determination unit. Therefore, the significance determination unit can consider the information on the acceleration in the significance determination.

On the other hand, each component of such a wireless terminal is controlled by the controller 310 so that each information is communicated and the operation is coordinated. However, not all components need to be controlled by the controller 310.

Next, a configuration of a server according to an embodiment of the present invention will be described.

4 shows a configuration of a server according to an embodiment of the present invention.

The server of this embodiment includes a network interface 540 for communicating with a network and a control unit 510 for controlling it. In addition, the server includes a location information acquisition unit 520 to obtain information related to the location of the wireless terminal. The location information acquisition unit 520 may be a location determination engine that receives location information from the wireless terminal and estimates a location. Alternatively, the location information acquisition unit 520 may be a type of communication module that receives the location estimated by the wireless terminal.

Based on the information acquired by the location information acquisition unit 520, the significance determination unit 550 determines the significance of the information. For this purpose, the significance determination unit 550 may receive previous information from the location information database 530 that stores the location information. In addition, the information on the acceleration from the wireless terminal may be received and considered in the significance determination.

When it is determined by the significance determination unit 550 that the meaninglessness (for example, small change, repeated meaninglessness) of a predetermined level or more is determined, the period changing unit 560 changes the position information transmission period. This change is mainly made by requesting the wireless terminal to change the transmission period, and specifically, may be implemented by changing the period flag.

Meanwhile, the controller 510 controls each component of the server and manages communication between them so that the above-described functions can be efficiently performed. However, it will be apparent to those skilled in the art that not all components need to be controlled by the controller 510.

The configuration of a server according to another embodiment of the present invention will be described with reference to FIG.

The embodiment of FIG. 5 is similar to the previous embodiment except for the positioning unit 620 and the RFID reader 670. The position determining unit 620 is connected to the RFID reader 670 and determines the position of the wireless terminal based on the reading result of the RFID reader 670. The RFID reader 670 is installed at the entrance, the exit or the inside of the predetermined area to read the RFID tag installed in the wireless terminal, and the read result is provided to the positioning unit 620.

The RFID reader 670 does not need to be a component of the server, and may be a component separate from the abnormal server communicating with the positioning unit 620. In this case, information about a predetermined area determined in advance by the location information database 630 system may be stored and provided to the location determiner 620.

The present invention has been described above with reference to specific embodiments of the present invention, but this is only illustrative and does not limit the scope of the present invention. Those skilled in the art can change or modify the described embodiments without departing from the scope of the present invention. Each of the functional blocks described in the present specification may be implemented by various known elements such as an electronic circuit, an integrated circuit, and an application specific integrated circuit (ASIC), and may be implemented separately, or two or more may be integrated into one. Components such as means described as separate in the specification and claims may be simply functionally distinct and may be physically implemented as one means, and components such as means described as a single element may be It can be made in combination. In addition, each method step described herein may be changed in order without departing from the scope of the present invention, and other steps may be added. In addition, the various embodiments described herein may be implemented independently as well as each other as appropriate. Therefore, the scope of the invention should be defined by the appended claims and their equivalents, rather than by the described embodiments.

1 is a flowchart illustrating a method for changing a location information transmission period according to an embodiment of the present invention.

2 is a flowchart illustrating a method of changing a location information transmission period according to another embodiment of the present invention.

3 is a block diagram illustrating a wireless terminal according to an embodiment of the present invention.

4 is a block diagram illustrating a server according to an embodiment of the present invention.

5 is a block diagram illustrating a server according to another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

310: control unit 320: sensor unit

330: RF driver 340: RF transceiver

350: period change unit 360: location information acquisition unit

370: Significance Determination

Claims (32)

In the method of changing the location information transmission period of the wireless terminal in the wireless terminal, Acquiring, by location information acquiring means, first information which is information related to the location of the wireless terminal; Calculating a difference between the first information and second information, which is information related to a location of a wireless terminal previously acquired, by the significance determining means, and determining the first information as meaningless when the difference is less than a predetermined threshold; And Changing, by the period changing means, the location information transmission period based on the determination result; And wherein said changing step changes said period when it is determined that said first information is meaningless more than a threshold number of times in succession. The method of claim 1, Wherein the first information and the second information include location information of a wireless terminal. The method of claim 1, And the determining step takes into account information on acceleration of the wireless terminal. delete delete delete In the method for changing the location information transmission period of the wireless terminal in the server for receiving the location information of the wireless terminal from the wireless terminal, Determining the position of the wireless terminal in position determining means; And Requesting, by the period changing means, to change the location information transmission period when the location corresponds to a predetermined zone; The determining of the location may include determining a location based on information obtained by reading a RFID tag installed in the wireless terminal by an RFID reader installed in the predetermined area. delete The method of claim 7, wherein The changing step is to block the location information transmission for a predetermined time, location information transmission period changing method. The method of claim 7, wherein The changing step blocks the transmission of the location information until it is determined that the location of the wireless terminal is out of the predetermined area. The method of claim 10, The changing may include determining whether or not the location of the wireless terminal is out of the predetermined area based on the information of the RFID reader installed in the predetermined area, reading the RFID tag installed in the wireless terminal. Way. delete delete A computer-readable recording medium having recorded thereon a program for causing the method of any one of claims 1 to 3, 7 or 9 to 11 to be executed on a computer. In a wireless terminal for transmitting location information to a server, Location information obtaining means for obtaining first information which is information related to a location of a wireless terminal; Meaningfulness determining means for calculating a difference between the first information and second information which is information relating to a position of a previously obtained wireless terminal, and determining the first information as meaningless when the difference is less than a predetermined threshold; And Period changing means for changing a transmission period of the location information based on the determination result; And said period changing means changes said period when said significance determination means determines that said first information is meaningless more than a threshold number of times in succession. The method of claim 15, The first information and the second information include location information of the wireless terminal. The method of claim 15, The wireless terminal further includes an acceleration sensor, And the significance determining means considers information on acceleration of the wireless terminal obtained from the acceleration sensor. delete delete A server that receives location information from a wireless terminal, Location information obtaining means for receiving first information from the wireless terminal, the first information being information relating to the location of the wireless terminal; Meaningfulness determining means for calculating a difference between the first information and second information which is information relating to a position of a previously obtained wireless terminal, and determining the first information as meaningless when the difference is less than a predetermined threshold; And Period changing means for requesting the wireless terminal to change the transmission period of the location information based on the determination result; And said period changing means requests said wireless terminal to change said period when said significance determination means determines that said first information is meaningless more than a threshold number of times in succession. The method of claim 20, The first information and the second information include location information of the wireless terminal. The method of claim 20, And the significance determining means considers information about acceleration of the wireless terminal. delete A server that receives location information from a wireless terminal, Location determining means for determining a location of the wireless terminal; And Period changing means for requesting the wireless terminal to change the location information transmission period when the location corresponds to a predetermined zone; And the position determining means determines the position based on information on which the RFID reader installed in the predetermined area reads the RFID tag installed in the wireless terminal. delete The method of claim 24, And the period changing means blocks the transmission of the location information for a predetermined time. The method of claim 24, And the period changing means blocks the transmission of the location information until it is determined that the location of the wireless terminal is out of the predetermined area. delete In the method for changing the location information transmission period of the wireless terminal in the server for receiving the location information of the wireless terminal from the wireless terminal, Receiving first information from the wireless terminal, the first information being information related to the location of the wireless terminal in the location information obtaining means; Calculating a difference between the first information and second information, which is information related to a location of a wireless terminal previously acquired, by the significance determining means, and determining the first information as meaningless when the difference is less than a predetermined threshold; And Requesting, by the period changing means, to change the location information transmission period based on the determination result; And the requesting step requests the wireless terminal to change the period when the first information is determined to be meaningless more than a threshold number of times in succession. The method of claim 29, Wherein the first information and the second information include location information of a wireless terminal. The method of claim 29, And the determining step takes into account information on acceleration of the wireless terminal. 32. A computer readable recording medium having recorded thereon a program for causing the method of any one of claims 29 to 31 to be executed on a computer.

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