KR102593931B1 - Method of selecting cell for measurement in a wireless access system - Google Patents

Abstract

The present invention relates to a wireless communication system, and more specifically, to a method of selecting an optimal measurement cell based on the strength of a signal received from a terminal. A method for a terminal to perform Observed Time Difference Of Arrival (OTDOA) location measurement in a wireless communication system according to an embodiment of the present invention includes the steps of measuring neighboring cells; Transmitting the first message including measurement information of at least one neighboring cell according to the measurement result to the base station so that the first message is delivered to the location server; Receiving a second message from the base station including OTDOA information for each of at least one neighboring cell according to the measurement result; And it may include performing OTDOA measurement using the at least one OTDOA information included in the second message.

Description

{METHOD OF SELECTING CELL FOR MEASUREMENT IN A WIRELESS ACCESS SYSTEM}

The present invention relates to a wireless communication system, and more specifically, to a method of selecting an optimal measurement cell based on the strength of a signal received from a terminal.

Recently, various location-based services have been provided through wireless communication systems. In order to provide such location-based services, technology for managing the mobility and location of moving objects, that is, terminals, is required. Location measurement technologies used to determine the location of a terminal include a single base station positioning (Cell-ID) method, a positioning method based on GPS (Global Positioning System) signals, a positioning method based on network signals, and a mixture of GPS signals and network signals. There is a hybrid positioning method that determines location. Among these, OTDOA (Observed Time Difference Of Arrival), a representative positioning method based on network signals, is used by the terminal for the purpose of measuring the PRS (Positioning Reference signal, OTDOA) transmitted by neighboring cells based on the serving cell. This is a technology that determines the difference in arrival time of a defined reference signal and converts it into a distance to estimate the location of the terminal.

This is explained with reference to FIG. 1 . Figure 1 is a diagram for explaining a general OTDOA method. In Figure 1, it is assumed that a terminal (UE) is located between three base stations (eNB1, eNB2, and eNB3).

The location server (E-SMLC: Evolved Serving Mobile Location Center) delivers the OTDOA cell information of the serving cell and the OTDOA cell information of neighboring cells to the terminal. Here, the OTDOA cell information of each cell may include cell information and PRS information. The terminal receives signals from each base station using OTDOA cell information, and calculates the difference in arrival time of PRS transmitted by neighboring cells based on the reference cell (here, eNB1), that is, Reference Signal Time Difference (RSTD). Report to location server. The location server can calculate the location of the terminal using the RSTD value received from the terminal.

Here, the OTDOA cell information held by the location server may be obtained from each base station. Cell information transmitted from the base station to the location server is information about cells physically configured in the base station, and one base station can have up to 18 cells. Therefore, it is inefficient to transmit OTDOA cell information set for many cells from the location server to the terminal as is, and may place a load on the terminal.

If the terminal is located at the border between base stations and only the OTDOA cell information value of the serving base station to which the terminal belongs is transmitted, the OTDOA cell information value of the neighboring cell that the terminal can actually measure may not be transmitted. Because this reduces location accuracy, it is desirable for the server (E-SMLC) to also transmit the value of the OTDOA cell information of the surrounding base station to obtain better measurement results.

However, in the OTDOA method implemented in a general wireless communication system, the location server transmits only the cell information of the serving base station to the terminal, and there was no algorithm for selecting the OTDOA cell of the surrounding base station to provide information to the terminal. Even if one nearby base station is selected, if OTDOA cell information for all cells of that base station is transmitted to the terminal, the load on the server increases, and the terminal also has to measure OTDOA for cells that cannot actually be measured, resulting in inefficiency.

The present invention is intended to provide a method and a device for performing OTDOA measurement more efficiently using signals received by a terminal.

In particular, the present invention is intended to provide a method by which a terminal can more efficiently select a cell on which to perform OTDOA cell measurement, and a device for performing the same.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below. You will be able to.

A method for a terminal to perform Observed Time Difference Of Arrival (OTDOA) location measurement in a wireless communication system according to an embodiment of the present invention includes the steps of measuring neighboring cells; Transmitting the first message including measurement information of at least one neighboring cell according to the measurement result to the base station so that the first message is delivered to the location server; Receiving a second message from the base station including OTDOA information for each of at least one neighboring cell according to the measurement result; And it may include performing OTDOA measurement using the at least one OTDOA information included in the second message.

In addition, in a wireless communication system according to an embodiment of the present invention, a method for a location server to perform an OTDOA (Observed Time Difference Of Arrival) location measurement procedure is to measure at least one neighboring cell according to the result of measuring neighboring cells of the terminal. Obtaining measurement information through the serving base station of the terminal; determining at least one base station including at least one cell included in the acquired measurement information from previously stored base station information; Receiving OTDOA cell information from each of the at least one base station; And it may include transmitting OTDOA cell information corresponding to each of at least one cell included in the acquired measurement information among the obtained OTDOA cell information to the serving base station so that it can be transmitted to the terminal.

In addition, a method for a serving base station to perform an OTDOA (Observed Time Difference Of Arrival) location measurement procedure for a terminal in a wireless communication system according to an embodiment of the present invention is based on the first message received from the terminal, transmitting a second message containing measurement information of at least one neighboring cell to a location server; And when a third message containing OTDOA information for each of the at least one neighboring cell is received from the location server, transmitting the third message to the terminal.

In addition, a terminal device that performs OTDOA (Observed Time Difference Of Arrival) location measurement in a wireless access system according to an embodiment of the present invention includes a processor; And it may include a wireless communication (RF) module for transmitting and receiving wireless signals to and from the outside according to the control of the processor. Here, the processor measures a neighboring cell, transmits the first message containing measurement information of at least one neighboring cell according to the result of the measurement to the base station, and transmits the first message to the base station so that the first message is delivered to the location server. When a second message containing OTDOA information for each of at least one neighboring cell according to the result is received from the base station, OTDOA measurement can be controlled to be performed using the at least one OTDOA information included in the second message. there is.

According to at least one embodiment of the present invention, the following effects are achieved.

OTDOA measurement can be performed more efficiently using the signal received by the terminal.

In particular, since OTDOA cell information about cells that the terminal can actually receive and have strong signals is delivered to the terminal, efficient and accurate OTDOA measurement is possible.

The effects that can be obtained from the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the description below. will be.

Figure 1 is a diagram for explaining a general OTDOA method.
Figure 2 is a flowchart showing an example of a process in which an OTDOA measurement cell is selected based on a signal received by a terminal according to an embodiment of the present invention.
Figures 3a and 3b show an example of a process in which a location server acquires information on neighboring cells of a terminal according to an embodiment of the present invention.
Figure 4 shows another example of a process in which a location server acquires information on neighboring cells of a terminal according to an embodiment of the present invention.
Figure 5 is a diagram illustrating a process of selecting a base station to request OTDOA cell information in a location server according to an embodiment of the present invention.
FIG. 6 is a diagram illustrating a process in which a cell to be included in the auxiliary information is selected when the location server provides auxiliary information to the terminal according to an embodiment of the present invention.
Figure 7 is a diagram for explaining information exchanged between a terminal and a location server according to an embodiment of the present invention.
Figure 8 is a block diagram showing an example of the structure of a transmitting end and a receiving end as another embodiment of the present invention.

Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. However, identical or similar components will be assigned the same reference numbers regardless of reference numerals, and duplicate descriptions thereof will be omitted. The suffixes “module” and “part” for components used in the following description are given or used interchangeably only for the ease of preparing the specification, and do not have distinct meanings or roles in themselves.

Additionally, in describing the embodiments disclosed in this specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in this specification, the detailed descriptions will be omitted. In addition, the attached drawings are only for easy understanding of the embodiments disclosed in this specification, and the technical idea disclosed in this specification is not limited by the attached drawings, and all changes included in the spirit and technical scope of the present invention are not limited. , should be understood to include equivalents or substitutes.

For accurate OTDOA location measurement, it is very important to measure OTDOA for cells that can be measured from the terminal side and have strong reception strength to improve location accuracy. Therefore, in one embodiment of the present invention, it is proposed to transmit the OTDOA cell information value to the terminal based on the cell information obtained by having the terminal measure and report neighboring cells during the OTDOA procedure.

To this end, according to an aspect of this embodiment, the serving base station may perform an RRC connection re-establishment procedure to obtain cell information that the terminal can measure at its current location (hereinafter referred to as “Proposal 1” for convenience).

In addition, according to one aspect of this embodiment, the terminal transmits the measurement results of the neighboring cells to the location server, and the location server uses the information on the neighboring cells obtained from the terminal to transmit the OTDOA cell to the base station corresponding to the cell measured by the terminal. Information may be requested (hereinafter referred to as “Proposal 2” for convenience).

In addition, according to one aspect of this embodiment, the location server can provide information about the OTDOA cell that the terminal will actually measure by matching the OTDOA cell information received from the base stations and the cell measurement result received from the terminal (hereinafter, , for convenience referred to as “Proposal 3”).

The above-described process will be described in more detail with reference to FIG. 2.

Figure 2 is a flowchart showing an example of a process in which an OTDOA measurement cell is selected based on a signal received by a terminal according to an embodiment of the present invention.

Referring to FIG. 2, first, the location server (E-SMLC) transmits a Request capabilities message to the UE to check whether the UE supports OTDOA (S201), and the UE provides capabilities. ) A message is sent to the location server (E-SMLC) to determine whether OTDOA is supported (S202).

The base station (eNB) may perform an RRC connection reconfiguration procedure to obtain information (PCI, frequency information) about cells that the terminal can measure at its current location (S203). This is a procedure corresponding to the above-mentioned proposal 1, where the base station transmits an RRC connection reset message to the terminal. In this message, a report configuration value can be set to obtain information on cells that the terminal can currently measure. there is. The terminal measures neighboring cells according to the settings of the corresponding message and transmits this to the server (via the serving base station) (S204). Cell information transmitted from the terminal to the server may include ECGI (E-UTRAN Cell Global Identifier), a unique identifier that identifies the base station cell, PCI (Physical Cell Identifier), a physical cell identification factor, and frequency information.

The process by which this cell information is transmitted from the terminal to the location server will be described in more detail later with reference to FIGS. 3A to 4B.

Next, in a process corresponding to proposal 2 of this embodiment, the location server (E-SMLC) sends an OTDOA information request message to each base station that matches the cell information (ECGI, PCI, frequency information) obtained from the terminal. Transmit to request the OTDOA cell information value (Cell information, PRS setting information) (S205). In response, the base station transmits the OTDOA cell information value through an OTDOA information response message (S206).

Processes S205 and S206 will be described in more detail later with reference to FIG. 5.

In a process corresponding to Proposal 3 of this embodiment, the location server matches the cell information received from the terminal with the OTDOA cell information value obtained from the base station, and includes OTDOA cell information about cells that the terminal can actually receive and that have strong signals. A Provide Assistance Data message is transmitted (S207).

Accordingly, the location server requests the terminal to measure location (Request Location Information) (S208), and the terminal performs OTDOA measurement (S209) and reports (Provide Location Information) according to the OTDOA cell information value obtained in step S207 ( S210).

Hereinafter, the processes corresponding to the above-mentioned proposal 1 (i.e., S203 and S204) will be described in more detail with reference to FIGS. 3 and 4.

Figures 3a and 3b show an example of a process in which a location server acquires information about cells around a terminal according to an embodiment of the present invention.

First, referring to FIG. 3A, after the OTDOA capabilities procedure (i.e., steps S201 and S202 in FIG. 2), the location server (E-SMLC) transmits a message to the base station to request neighboring cell measurement from the terminal (UE). (S310). Here, the message is preferably an E-CID Measurement Initiation Request message, but is not necessarily limited thereto.

The base station that receives the request message from the location server transmits an RRC Connection Reconfiguration message to the terminal (S320). At this time, the frequency and reporting method to be measured by the terminal may be set in the RRC connection reset message transmitted to the terminal. For example, the RRC connection reset message can be set as shown in Table 1 below.

Referring to Table 1, for the reporting method, the trigger type (triggerType) can be set to "periodical" and the purpose (Purpose) can be set to "reportStrongestCells", and the maximum number of cells to measure ( maxReportCells) can also be set (here 6).

As the terminal completes configuration according to the RRC connection reconfiguration message, it transmits an RRC Connection Reconfiguration Complete message to the base station in response (S330) and performs measurements on neighboring cells.

The terminal can transmit information (PCI, RSRP, RSRQ) of cells that can be measured within the set maximum number of cells to the base station through a Measurement Report message (S340). Accordingly, the base station transmits cell information (ECGI, PCI, frequency information, etc.) obtained from the terminal to the location server through an E-CID Measurement Initiation Response message (S350).

Specifically, as shown in Figure 3b, when the terminal performs measurements on cells with PCIs of 123, 112, and 125, respectively, the terminal can transmit cell information as shown in Table 2 below to the base station.

PCI frequency 123 850M
112 850M
125
850M

Of course, in addition to the information in Table 2, additional information related to signal quality such as RSRP and RSRQ may be included for each cell. That is, the measurement report message may include information such as PCI, RSRP, RSRQ, and frequency.

The base station can transmit ECGI information corresponding to each PCI to the location server along with the information received from the terminal.

Meanwhile, in Figure 3a, the location server explicitly instructed the base station to request a neighboring cell for the terminal, but the base station may immediately initiate the RRC reconfiguration procedure without a request from the location server. This is explained with reference to FIG. 4 .

Figure 4 shows another example of a process in which a location server acquires information on neighboring cells of a terminal according to an embodiment of the present invention.

Referring to FIG. 4, unlike FIG. 3a, even if the location server does not first transmit a message (e.g., E-CID Measurement Initiation Request message) requesting the base station to measure a cell surrounding the terminal, the base station sends an RRC connection reconfiguration message to the terminal. can be transmitted (S410). Accordingly, the terminal responds with an RRC connection reset completion message (S420), and after measuring neighboring cells, a measurement report message can be transmitted to the base station (S430).

Since steps S410 to S430 are similar to steps S320 to S340 of FIG. 3A, overlapping descriptions will be omitted for brevity of the specification.

Since there was no request from the location server, the base station, unlike Figure 3a (i.e., instead of the E-CID Measurement Initiation Response message), transmitted the information on the surrounding cells measured by the terminal to the location server through the E-CID Measurement Report message. (S440).

Next, Proposal 2 of this embodiment will be described in more detail with reference to FIG. 5.

Figure 5 is a diagram illustrating a process of selecting a base station to request OTDOA cell information in a location server according to an embodiment of the present invention.

As described above with reference to FIG. 2, the location server that obtains the information on the neighboring cells measured by the terminal (S204) transmits an OTDOA information request message to the base station (S205). However, in order to perform step S205, the location server needs to first determine the base station to which the request message will be transmitted.

For example, assume a situation where the location server obtains the information shown in Table 2 and previously holds the base station information shown in (a) of FIG. 5. In this case, the location server searches for a base station with a PCI that matches the PCI obtained from the terminal in the base station information it possesses. That is, Table 2 includes PCI 123, 112, and 125. According to (a) of Figure 5, PCI 123 and 112 are the PCI of the cell included in base station A (eNB A), and PCI 125 is the PCI of the cell included in base station B (eNB B). ) matches the PCI of the cell included in Accordingly, the location server transmits an OTDOA information request message to base stations A and B, respectively, and receives an OTDOA information response message from each of base stations A and B (corresponding to S206 in FIG. 2).

As the location server receives the OTDOA information response message from each base station, the OTDOA information value for each cell may be added to the base station information held by the location server for each of base stations A and B, as shown in (b) of FIG. 5.

Next, Proposal 3 of this embodiment will be described in more detail with reference to FIG. 6.

FIG. 6 is a diagram illustrating a process in which a cell to be included in the auxiliary information is selected when the location server provides auxiliary information to the terminal according to an embodiment of the present invention.

Each information state in FIG. 6 is assumed to follow in FIG. 5.

As described above with reference to FIG. 2, the location server obtains OTDOA cell information from each base station (S206) and when the information as shown in (b) of FIG. 5 is obtained, the determined OTDOA cell information is determined by determining the cell information to measure OTDOA. A Provide Assistance Data message containing a value is transmitted to the terminal (S207).

Here, the OTDOA cell information to be transmitted to the terminal may be determined as information on the cell corresponding to the PCI of the neighboring cell measurement information transmitted by the terminal. That is, in (a) of FIG. 6, the OTDOA information value corresponding to PCI 123 and 112 of base station A and the OTDOA information value corresponding to PCI 125 of base station B may be included in the auxiliary data provision message. Finally, the auxiliary data provision message may include information as shown in (b) of FIG. 6. Therefore, from the terminal's perspective, OTDOA cell information about cells that can be measured based on signal strength can be provided to the terminal.

The above-mentioned proposal process is explained again from the perspective between the terminal and the location server as shown in Figure 7.

Figure 7 is a diagram for explaining information exchanged between a terminal and a location server according to an embodiment of the present invention.

FIG. 7 is a flow chart reorganizing the process described above with reference to FIG. 2 from the perspective of data exchange between the terminal and the location server excluding the base station. Even if the base station is omitted, each information is exchanged between the terminal and the location server via the serving base station. It is obvious to those skilled in the art.

Referring to FIG. 7, the terminal (UE) first transmits information on neighboring cells measured by the terminal (UE) to the location server (E-SMLC) (710). At this time, the information transmitted may be as shown in Table 2, and as described above, information related to signal quality such as RSRP and RSRQ may be further included.

The location server uses the cell information measured by the terminal and the OTDOA cell information obtained from the base station to transmit information about the OTDOA cell to be measured by the terminal to the terminal through an auxiliary data provision message (S720). At this time, the OTDOA cell information included in the auxiliary data provision message may be configured as shown in (b) of FIG. 6.

The terminal may perform OTDOA measurement using the OTDOA cell information in the auxiliary data provision message and report each RSTD value as a result to the location server (S730).

Terminal and base station structure

Hereinafter, as another embodiment of the present invention, a terminal and a base station in which the above-described embodiments of the present invention can be performed will be described.

The terminal can operate as a transmitter in the uplink and as a receiver in the downlink. Additionally, the base station may operate as a receiver in the uplink and as a transmitter in the downlink. That is, the terminal and base station may include a transmitter and receiver for transmission of information or data.

The transmitter and receiver may include processors, modules, parts and/or means, etc. for carrying out embodiments of the present invention. In particular, the transmitter and receiver may include a module (means) for encrypting a message, a module for interpreting the encrypted message, an antenna for transmitting and receiving a wireless signal, etc. An example of such a transmitting end and a receiving end will be described with reference to FIG. 8.

Figure 8 is a block diagram showing an example of the structure of a transmitting end and a receiving end as another embodiment of the present invention.

Referring to FIG. 8, the left side shows the structure of the transmitting end, and the right side shows the structure of the receiving end. The transmitting end and the receiving end each have an antenna (5, 10), a processor (20, 30), a transmission module (Tx module (40, 50)), a receiving module (Rx module (60, 70)), and memory (80, 90). It can be included. Each component can perform a corresponding function. Below, each component is described in more detail.

The antennas 5 and 10 transmit signals generated in the transmission modules 40 and 50 to the outside, or receive wireless signals from the outside and transmit them to the reception modules 60 and 70. If the multiple antenna (MIMO) function is supported, two or more may be provided.

The antenna, transmission module, and reception module can together form a wireless communication (RF) module.

Processors 20 and 30 typically control the overall operation of the receiving end and the transmitting end. For example, a controller function for performing the embodiments of the present invention described above, a MAC (Medium Access Control) frame variable control function according to service characteristics and propagation environment, a handover function, authentication and encryption functions, etc. It can be done.

In particular, the processor of the terminal can control the wireless communication module so that the measurement results for neighboring cells are reported to the base station in the form of a report according to the setting value of the RRC connection reset message received from the base station. In addition, when the terminal's processor receives OTDOA cell information for at least one cell from the location server, it performs OTDOA measurement using the information and transmits the resulting RSTD value to the base station so that it can be transmitted to the location server. You can control the wireless communication module for this purpose.

In addition, the processor of the base station can request neighboring cell measurement from the terminal by sending an RRC connection reset message to the terminal with or without a request from the location server. When OTDOA cell information is requested from the location server, it can provide it to the location server. You can. In addition, an auxiliary data provision message containing OTDOA cell information about cells around the terminal can be received from the location server and delivered to the terminal, and the OTDOA measurement results of the terminal can be received from the terminal and delivered to the location server. Of course, the base station can use wired communication such as a backbone network for communication with other base stations or location servers, and it is obvious to those skilled in the art that a wired communication module (not shown) may be additionally provided for this purpose.

In addition, the processors of the terminal and the base station can perform overall control operations of the operation processes disclosed in the above-described embodiments.

The transmission modules 40 and 50 may perform predetermined coding and modulation on data scheduled from the processors 20 and 30 to be transmitted externally and then transmit the data to the antenna 10.

The receiving modules 60 and 70 perform decoding and demodulation on the wireless signals received from the outside through the antennas 5 and 10, restore the original data to the processors 20 and 30, and It can be delivered.

The memories 80 and 90 may store programs for processing and controlling the processors 20 and 30, and may also perform a function for temporarily storing input/output data. In addition, the memories 80 and 90 may be flash memory type, hard disk type, multimedia card micro type, or card type memory (for example, SD or XD memory). etc.), RAM (Random Access Memory), SRAM (Static Random Access Memory), ROM (Read-Only Memory, ROM), EEPROM (Electrically Erasable Programmable Read-Only Memory), PROM (Programmable Read-Only Memory), It may include at least one type of storage medium among magnetic memory, magnetic disk, and optical disk.

Meanwhile, the base station has a controller function, Orthogonal Frequency Division Multiple Access (OFDMA) packet scheduling, Time Division Duplex (TDD) packet scheduling, and channel multiplexing functions to perform the embodiments of the present invention described above. , high-speed traffic real-time control function, handover function, authentication and encryption function, packet modulation and demodulation function for data transmission, high-speed packet channel coding function, and real-time modem control function are performed through at least one of the modules described above, It may further include separate means, modules, or parts to perform these functions.

The present invention may be embodied in other specific forms without departing from the spirit and essential features of the present invention. Accordingly, the above detailed description should not be construed as restrictive in all respects and should be considered illustrative. The scope of the present invention should be determined by reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present invention are included in the scope of the present invention. In addition, claims that do not have an explicit reference relationship in the patent claims can be combined to form an embodiment or included as a new claim through amendment after filing.

Claims (20)

In a method for a terminal to perform OTDOA (Observed Time Difference Of Arrival) location measurement in a wireless communication system,
measuring surrounding cells;
Transmitting the first message including measurement information of at least one neighboring cell according to the result of the neighboring cell measurement to the base station so that the first message is delivered to the location server;
Receiving a second message from the base station including OTDOA information for at least one neighboring cell according to the first message; and
Including performing OTDOA measurement using the at least one OTDOA information included in the second message,
The step of transmitting the first message is,
An OTDOA location measurement method performed based on information about the reporting method upon receiving an RRC reconfiguration message including information about the reporting method of the first message from the base station. According to clause 1,
The first message is,
An OTDOA location measurement method including frequency information and physical cell identifier (PCI) information for each of at least one neighboring cell according to the results of the neighboring cell measurement. delete According to clause 1,
The first message includes a Measurement Report message,
OTDOA location measurement method, wherein the second message includes a Provide Assistance Data message. According to clause 1,
The second message is,
OTDOA location measurement method transmitted from the location server and received through the base station. delete delete delete delete delete In a method for a serving base station to perform an OTDOA (Observed Time Difference Of Arrival) location measurement procedure for a terminal in a wireless communication system,
Transmitting, to the terminal, an RRC reconfiguration message containing information on a reporting method of a first message including measurement information on at least one neighboring cell according to a neighboring cell measurement result of the terminal;
Based on the first message received from the terminal in response to the information on the reporting method, transmitting a second message containing measurement information of at least one neighboring cell of the terminal to a location server; and
When a third message containing OTDOA information for each of the at least one neighboring cell is received from the location server, transmitting the third message to the terminal. According to clause 11,
The first message is,
Contains frequency information and physical cell identifier (PCI) information for each of the at least one neighboring cell,
The second message is,
OTDOA location measurement method, including frequency information of each of the at least one neighboring cell, the physical cell identifier (PCI) information, and unique cell identifier (ECGI) information. delete According to clause 11,
The first message includes a Measurement Report message,
The second message includes an E-CID measurement start response message or an E-CID measurement report message,
OTDOA location measurement method, wherein the third message includes a Provide Assistance Data message. According to clause 14,
The second message is,
When an E-CID measurement start request message for requesting measurement of a neighboring cell of the terminal is received from the location server, it is the E-CID measurement start response message,
If the E-CID measurement start request message is not received, the OTDOA location measurement method is the E-CID measurement report message. In a terminal device that performs OTDOA (Observed Time Difference Of Arrival) location measurement in a wireless access system,
processor; and
It includes a wireless communication (RF) module for transmitting and receiving wireless signals to and from the outside according to the control of the processor,
The processor,
Receives an RRC reconfiguration message containing information about a reporting method of the first message from the base station, measures neighboring cells, and provides measurement information on at least one neighboring cell according to a result of the neighboring cell measurement to the first message. The first message is transmitted to the base station according to the information on the reporting method so that it is included in the message and delivered to the location server, and a second message containing OTDOA information about at least one neighboring cell according to the first message is sent. When received from the base station, the terminal device controls to perform OTDOA measurement using the at least one OTDOA information included in the second message. According to clause 16,
The first message is,
A terminal device comprising frequency information and physical cell identifier (PCI) information for each of at least one neighboring cell according to a result of the neighboring cell measurement. delete According to clause 16,
The first message includes a Measurement Report message,
The terminal device wherein the second message includes a Provide Assistance Data message. According to clause 16,
The second message is,
A terminal device transmitted from the location server and received through the base station.

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