KR100856228B1 - IPDL operation and superimposition prevention method in general mobile communication system - Google Patents

Abstract

The present invention provides a method for operating IPDL of a base station and preventing overlapping of IPDL between base stations in a general-purpose mobile communication system. To this end, the present invention uses the time difference between a reference base station located in a reference cell included in a mobile communication terminal and a received signal received by the mobile communication terminal from a neighbor base station located in at least one neighboring cell adjacent to the reference cell. A method of operating an IPDL of a general-purpose mobile communication system for identifying a location of a mobile communication terminal, the method comprising: measuring a time difference between a received signal received from the reference base station and neighboring base stations in the mobile communication terminal; Transmitting, by the controller, a measurement control message requesting the measured value measured by the time difference to the mobile communication terminal; and transmitting, by the mobile communication terminal, a measurement report message including the measured value in response to the measurement control message. Transmitting to the base station; The controller activates the IPDL of the reference base station and the IPDL of the neighboring base station which has transmitted the received signal to the mobile communication terminal among the neighboring base stations based on the measured value.

IPDL, TODA, SFN-SFN.

Description

IPDEL OPERATING IPDL AND HOLDING IN CHECK OVERLAPPING OF IPDL IN A UNIVERSAL MOBILE TELECOMMUNICATIONS SYSTEM}             

1 is a block diagram of a general-purpose mobile communication system applied to the present invention;

2 is a flowchart of determining the position of a mobile communication terminal in a TDOA method in a general-purpose mobile communication system applied to the present invention;

3 is a flowchart of controlling an operation of an IPDL of each base station in a base station controller according to an embodiment of the present invention;

4a and 4b is a block diagram showing the overlapping IP during conventional IPDL operation,

4c is a block diagram illustrating an IP in which an overlapping part is removed during an IPDL operation according to an embodiment of the present invention;

The present invention relates to a general-purpose mobile communication system, and more particularly, to a method of operating an IPDL of a base station in a general-purpose mobile communication system and preventing the overlap of IPDLs between the base stations.

Recently, the Federal Communications Commission (FCC) decided to introduce an E (911) service, which had been postponed in the wake of the US terrorist incident. In response to this, companies producing mobile communication terminals are spurring to develop mobile communication terminals equipped with a GPS (Global Positioning System) function. Among them, Lucent Technology of the United States has already developed a technology that can accurately measure the position of the mobile communication terminal within a radius of about 4.6m (15 feet). Developed by Lucent Technology, the technology delivers high precision within a radius of 30 meters (100 feet) indoors and a radius of 15 feet (4.6 meters) outdoors.

However, when determining the location of the mobile communication terminal using GPS, additional equipment must be added to the base station and the mobile service exchange center as well as the mobile communication terminal.

As described above, a mobile communication system for tracking a location of a mobile communication terminal using GPS is mainly used for a synchronous mobile communication system. Of course, the asynchronous mobile communication system also uses GPS to track the location of the mobile communication terminal. However, in the asynchronous mobile communication system, the location of the mobile communication terminal is mainly determined using a cell-ID method or a time difference of arrival (TODA) method. The cell-ID method refers to a method of identifying a location of a sector including a mobile communication terminal by dividing a cell into a plurality of sectors. Such a cell-ID method can determine the approximate location of the mobile communication terminal.

In addition, the TODA method includes a time difference between a reference base station located in a reference cell including a mobile communication terminal and a received signal received by the mobile communication terminal from at least one neighboring base station located in at least one neighboring cell adjacent to the reference cell. It refers to a method for identifying the location of the mobile communication terminal using. Although the TODA method is not more accurate than the GPS method, the position of the mobile communication terminal can be determined more accurately than the cell-ID method. The TODA method uses the principle of Time Of Arrival (TOA), and the position of the mobile communication terminal is a point where a hyperbola formed from three base stations intersects the mobile communication terminal as shown in FIG.

However, in order to determine the location of the mobile communication terminal in the above manner, the mobile communication terminal must receive a received signal from at least three base stations. That is, when the mobile communication terminal is very close to the reference base station and the strength of the received signal received from the reference base station is strong, the mobile communication terminal cannot receive the received signal from the neighbor base station. Typically, such a problem is referred to as a near / far problem. Due to the above problem, there is a problem that the location of the mobile communication terminal cannot be determined.

In order to solve the above problems, 3DPP (Idle Period DownLink) technology has recently been proposed. IPDL technology temporarily stops the channel setting of the reference base station that has received the received signal from the base station to the mobile communication terminal and the neighboring base station, and thus the mobile communication terminal receives the received signal of the adjacent base station that has not transmitted the received signal to the mobile communication terminal. Says technology.

For example, in FIG. 1, if it is assumed that a received signal is received only from the reference base station 2 and the neighbor base station A 4, the mobile communication terminal is activated by the IPDL of the reference base station 2 and the neighbor base station A 4. The received signal of B (6) can be received. As a result, the position of the mobile communication terminal can be determined. The above technique is used to improve the visibility of the neighboring base station cell of the mobile communication terminal.

On the other hand, the IP (Idle Period) is set in a predetermined pseudo random method according to the parameter of the upper layer, and the base station controller activates the IPDL of the base station during cell setup of the mobile communication terminal. . The parameter used in the IPDL and the IP position (IP_Position) are calculated by Equation 1 below.

는 IP를 포함하는 무선 프레임(Radio Frame)의 시작점과 다음 IP를 포함하는 무선 프레임간의 무선 프레임 수이고,

는 IP의 길이로써, CPICH(Common PIlot CHannel)의 심벌(symbol)을 나타내며,

은 한 기지국 내의 복수개 섹터간의 IP의 동기화를 위해 사용되는 셀 고유의 옵셋이고, Seed는 Pseudo Random Number Generator를 위한 Seed를 말한다.

Is the number of radio frames between the starting point of the radio frame including the IP and the radio frame including the next IP,

Denotes a symbol of CPICH (Common PIlot CHannel) as a length of IP,

Is a cell-specific offset used for IP synchronization between a plurality of sectors within a base station, and Seed is a seed for a pseudo random number generator.

However, when activating the IPDL of the base station through the cell configuration as described above, there is a problem that the IPDL overlaps between the base stations. Therefore, academia or industry has been researching to solve the above problems by optimizing common values of IPDL parameters such as BER (Bit Error Rate), FER (Frame Error Rate), and Minimizing Response Time when requesting location information. I'm working on a search.

However, even if the common values of IPDL parameters are equally applied to all base stations, the asynchronous mobile communication system does not synchronize between the base stations. Therefore, simply activating the IPDL of each base station by the difference of the IP offset is the IPDL of each base station. There is a possibility to overlap. Therefore, the function of the base station with the IPDL enabled is temporarily suspended, causing not only the loss of capacity of the base station and the inability to provide location information in real time, but also a problem of degrading the quality of other services.

 As described above, only a method of activating the IPDL when setting a cell of the mobile communication terminal is presented, and a specific IPDL operation method for minimizing capacity loss, BER, and FER of the base station has not been proposed yet.

Accordingly, an object of the present invention is to provide a method of operating an IPDL of a base station in a general purpose mobile communication system.

Another object of the present invention is to provide a method for preventing IPDL overlap between base stations in a general purpose mobile communication system.

According to an aspect of the present invention, a time difference between a reference base station located in a reference cell included in a mobile communication terminal and a received signal received from the neighbor base station located in at least one neighboring cell adjacent to the reference cell is received by the mobile communication terminal. A method for operating an IPDL of a general-purpose mobile communication system for identifying a location of the mobile communication terminal using a method, the method comprising: measuring a time difference between a received signal received from the reference base station and neighboring base stations in the mobile communication terminal; And transmitting, to the mobile communication terminal, a measurement control message requesting the measured value measured by the base station controller, and a measurement report message including the measured value in response to the measurement control message at the mobile communication terminal. To transmit to the base station controller And will be at the base station controller characterized in that to enable the child PD El of transmitting the received signal to the measure according to the movement of the eye PD El of the reference base station the neighboring base station communication terminal the neighboring base station.

According to another aspect of the present invention, there is provided a received signal received from a reference base station located in a reference cell included in a mobile communication terminal and a neighbor base station located in at least one adjacent cell adjacent to the reference cell. In the general-purpose mobile communication system for identifying the location of the mobile communication terminal using a time difference of, if the location of the mobile communication terminal is not known, the IPDL of the reference base station and the IDDL of one of the neighboring base stations A method for preventing overlapping of a device, the method comprising: checking a state of an IPDL of the reference base station and the neighboring base station, and performing IP synchronization between a plurality of sectors in the base station according to the states of the IPDL of the two base stations; Selectively setting the IP offset to the two base stations Characterized in that the process of preventing the overlap of IPDL of the base station.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

1 is a block diagram of a general-purpose mobile communication system applied to the present invention, Figure 2 is a flow chart for identifying the location of the mobile communication terminal in the TDOA method in the general-purpose mobile communication system applied to the present invention.

Referring to FIG. 1, a general-purpose mobile communication system includes a user equipment (UE) 8, a base station Node B 2, 4, 6, a radio network controller 10 (RNC) 10, and a location. It consists of a Measurement Measurement Unit (LMU) 14, a Service Mobile Location Center (SLMC) 12, and a Core Network (CN) 16. The UTRAN (UTMS Terrestrial Radio Access Network) consists of a base station 2, 4, 6, a base station controller 10, a position measuring unit 14, and a service mobile location center 12. The UTRAN is connected to the core network through the Iu interface.

The base stations 2, 4 and 6 are responsible for radio transmission with the mobile communication terminal 8 located in the cell area and are connected to the base station controller 10 via the Iub interface. These base stations 2, 4, 6 are composed of a plurality of base stations 2, 4, 6 in one base station controller 10. In the present invention, a plurality of base stations 2, 4, and 6 must be preceded by the premise that one base station controller 10 should be included.

The base station controller 10 controls the use and integrity of radio resources, handles a hand off requiring signal processing to the mobile communication terminal 8, and different base stations 2, 4, and 6 Diversity is supported. The base station controller 10 may be configured in plurality, and the plurality of base station controllers are connected through an Iur interface. In addition, the base station controller 10 selectively activates the IPDLs of the base stations 2, 4, and 6 according to an embodiment of the present invention, and the base stations 2 and 4 are prevented from overlapping the IPDL between the base stations 2, 4 and 6. 6).

The service mobile location center 12 is connected to the base station controller 10 through the Lb interface and manages the coordination and scheduling of resources necessary to perform the positioning of the mobile communication terminal 8.

 The position measuring unit 14 is a type B position measuring unit 14 which is connected to the base stations 2, 4, 6 via an Abis interface. When the position measuring unit 14 requests a relative time difference (RTD) measurement value from the base stations 2, 4 and 6, the position measuring unit 14 measures the relative time difference between the base stations 2, 4 and 6, and then measures the base station 2. , 4,6).

In the general mobile communication system configured as described above, the process of determining the location of the mobile communication terminal in the TODA method will be described in detail with reference to FIG. 2. In the first step, the base station controller 10 performs paging on the core network 16. Command to form a channel. The base station controller 10 forms a paging channel with the mobile communication terminal 8 of type 1 in step 4. Then, in step 6, RRC (Radio Resource Control) connection is established between the mobile communication terminal 8 and the base station controller 10. Thereafter, in step 8, an Iu connection is established between the mobile communication terminal 8 and the core network 16, and an authentication and encryption procedure is performed.

In operation 10, the core network 16 transmits a register message through the UTRAN so that the mobile communication terminal 8 requests location information. In step 12, the mobile communication terminal 8 transmits a register message corresponding to the message to the core network 16 through the UTRAN.

Thereafter, the core network 16 transmits a location request control signal to the base station controller 10 to determine the location of the mobile communication terminal 8 in step 14. In response, the base station controller 10 requests the base station 2, 4, 6 to start a round trip time (RTD) measurement in step 16 (Common Measurement Initiation Request). The base station 2, 4, 6 requests the RTD measurement value from the position measuring unit 14 in step 18, and the position measuring unit 14 sends the RTD measurement value to the base station 2, 4, 6 in step 20. send. When the RTD measurement value is transmitted to the base station 2, 4, 6, the base station 2, 4, 6 sends a common measurement initiation response to the base station controller 10 in step 22.

Subsequently, the base station controller 10 requires measurement control for requesting measurement values obtained by measuring the time difference between the received signals received from the reference base station 2 and the adjacent base stations 4 and 6 in the mobile communication terminal 8 in step 24. (Measurement Control) message is transmitted to the mobile communication terminal (8). That is, the base station controller 10 transmits to the mobile communication terminal 8 a measurement control message requesting a measurement value of the SFN (System Frame Number) -SFN time difference between the reference base station 2 and the adjacent base stations 4 and 6. .

The mobile communication terminal 8 then measures the SFN-SFN time difference between the reference base station 2 and the neighbor base station A 4 and the SFN-SFN time difference between the reference base station 2 and the neighbor base station B 6. Thereafter, the mobile communication terminal 8 transmits the two measurement values measured in step 26 to the base station controller 10 by including them in the measurement report message.

On the other hand, the mobile communication terminal 8 cannot measure the SFN-SFN time difference when it does not receive the received signal from the adjacent base stations 4 and 6. That is, the number of measured values is zero when the received signals are not received from two neighboring base stations 4 and 6, and the number of measured values is one when the received signals are received from one neighboring base station.

The base station controller 10 determines the activation of the IPDL of the three base stations 2, 4, 6 based on the measurement report message received in step 28. That is, the base station controller 10 checks whether there are two or more measured values in step 102 as shown in FIG. 3. If there are two or more received measurement values, the base station controller 10 performs step 30, which will be described below.

If the received measurement value is less than two, the base station controller 10 checks whether the measurement report message has been received from the mobile communication terminal 8 more than once in step 104. If the measurement report message has been received from the mobile communication terminal 8 more than once, the base station controller 10 does not know the position of the mobile communication terminal 8 in the TODA method and activates the IPDL of the base stations 2, 4, 6. Shut down without letting it.

On the other hand, if the measurement report message is received from the mobile communication terminal 8 less than two times, the base station controller 10 checks whether the number of neighboring base stations 4 and 6 that has transmitted the received signal is one in step 106. That is, the base station controller 10 checks whether the received measurement value is one. If there is no measurement received from the mobile communication terminal 8, the base station controller 10 activates the IPDL of the reference base station 2 in step 108. As a result, the mobile communication terminal 8 can receive the received signals from the adjacent base stations 4 and 6 and measure the SFN-SFN time difference.

In step 110, the base station controller 10 transmits a measurement control message requesting the measurement value to the mobile communication terminal 8, and receives a measurement report message including the measurement value from the mobile communication terminal 8. This allows the base station controller 10 to receive two measurements.

On the other hand, if the number of neighboring base stations 4 and 6 that has transmitted the received signal to the mobile communication terminal 8 is one, that is, if the received measurement value is one, the base station controller 10 and the reference base station 2 in step 114 The active state of the IPDL of the neighboring base station 4 is checked.

If the IPDL of the reference base station 2 and the neighboring base station 4 is active, the base station controller 10 transmits the measurement control message requesting the measurement value to the mobile communication terminal 8 in step 110 as described above. Receive a measurement report message including the measured value from the mobile communication terminal (8).

If the IPDL of the neighboring base station 4 is active and the IPDL of the reference base station 2 is inactive, the base station controller 10 activates the IPDL of the reference base station 2 in step 120. If the IPDL of the reference base station 2 is active and the IPDL of the neighboring base station 4 is inactive, the base station controller 10 activates the IPDL of the neighboring base station 4 in step 118.

As described above, the base station controller 10 selectively activates two IPDLs of the reference base station 2 and the neighboring base station 4 according to the measurement values received from the mobile communication terminal 8. The above measured values can be received.

In step 30, the base station controller 10 requests the base station 2, 4, 6 to start a round trip time (RTT) measurement (Dedicated Measurement Initiation Request). Accordingly, the base stations 2, 4 and 6 make a Dedicated Measurement Initiation Response to the base station controller 10 in step 32.

The base station controller 10 transmits the time difference measurement value received from the mobile communication terminal 8 and the RTT measurement value received from each base station 2, 4, 6 to the service mobile location center 12 in step 36. . The service mobile location center 12 then calculates the position of the mobile communication terminal 8 based on the time difference measurement and the RTT measurement transmitted from the base station controller 10. As described above, the position of the mobile communication terminal 8 is a point at which the hyperbola formed from the three base stations 2, 4 and 6 intersects the mobile communication terminal 8.

Thereafter, the service mobile location center 12 transmits the location information of the mobile communication terminal 8 to the base station controller 10 in step 36, and the base station controller 10 transmits the mobile communication to the core network 16 in step 38. The location report message of the terminal 8 is transmitted. Then, the core network 16 releases the Iu connection with the base station controller 10 in step 40 (Iu Release Command). Correspondingly, when the base station controller 10 and the mobile communication terminal 8 release the RRC connection in steps 42 and 44, in step 46, the Iu connection between the base station controller 10 and the core network 16 is released.

As described above, the base station controller 10 selectively activates IPDLs of the reference base station 2 and the neighbor base station 4 based on the number of SFN-SFN time differences included in the measurement report message received from the mobile communication terminal 8. The position of the mobile communication terminal 8 can be grasped.

On the other hand, if the base station controller 10 is the IPDL of any one of the reference base station 2 and the neighbor base station 4 is active in step 116, the base station controller 10 is based on the status of the IPDL of the two base stations (2, 4) An IP offset for performing IP synchronization between a plurality of sectors in the sector may be selectively set at the two base stations 2 and 4 to prevent overlapping of the IPDL between the two base stations 2 and 4.

In order to selectively set the IP offset, first, an IP offset difference between the reference base station 2 and the neighboring base station 4 should be obtained.

은 참조 기지국의 IP 옵셋이고,

은 인접 기지국의 IP 옵셋이며,

은 참조 기지국과 인접 기지국간의 IP 옵셋 차이다.

과

은 IP 옵셋에

을 적용한 옵셋이다.

은 참조 기지국과 인접 기지국간의 SFN의 차를 256으로 나눈 정수값에 1을 더한 값이며,

은 IPDL을 활성화할 기지국의 IP 옵셋에 추가로 적용될 추가 옵셋이다.

Is the IP offset of the reference base station,

Is the IP offset of the neighboring base station,

Is the IP offset difference between the reference base station and the neighbor base station.

and

In the IP offset

Offset by applying.

Is an integer value obtained by dividing the difference between SFNs between a reference base station and a neighbor base station by 256, and adding 1.

Is an additional offset to be applied in addition to the IP offset of the base station to activate the IPDL.

The base station controller 10 obtains an additional offset based on the IP offset difference, and then selectively applies the additional offset to the reference base station 2 and the neighbor base station 4 so that the reference base station 2 and the neighbor base station 4 Prevent nesting of IPDLs.

The method for obtaining the additional offset is as shown in Equations 3 to 6. If the IPDL of the reference base station is active and the IPDL of the reference base station precedes the IPDL of the neighboring base station, Equation 3 is obtained.

Equation 4 when the IPDL of the reference base station is active and the IPDL of the neighboring base station precedes the IPDL of the reference base station.

If the IPDL of the neighboring base station is active and the IPDL of the reference base station precedes the IPDL of the neighboring base station, Equation 5 is obtained.

If the IPDL of the neighboring base station is active and the IPDL of the neighboring base station precedes the IPDL of the reference base station, Equation 6 is given.                     

The base station controller 10 selectively applies the additional offset according to the active state and precedence of the IPDL of the reference base station 2 and the neighboring base station 4 as indicated in equation (3).

By selectively applying the additional offset as described above, the overlapped portions illustrated in FIGS. 4A and 4B may be removed as shown in FIG. 4C.

As described above, the IP offset may be selectively set in the reference base station and the adjacent base station to prevent the overlapping of the IPDL between the two base stations.

As described above, the location information service can be provided in real time by selectively activating the IPDL of the base station based on the measurement value received from the mobile communication terminal and setting the IP offset to prevent the overlapping of the base station's IPDL. In addition, there is an effect to minimize the activation time of the IPDL of the base station, and to minimize the capacity loss and degradation of service quality.

Claims (6)

The location of the mobile communication terminal using a time difference between a reference base station located in a reference cell included in the mobile communication terminal and a received signal received from the neighbor base station located in at least one adjacent cell adjacent to the reference cell to the mobile communication terminal. In the method of operating IPDL of the general-purpose mobile communication system for grasping, Measuring a time difference between received signals received from the reference base station and the adjacent base stations in the mobile communication terminal; Transmitting, by a base station controller, a measurement control message requesting the measured value of the time difference to the mobile communication terminal; Transmitting, by the mobile communication terminal, a measurement report message including the measurement value to the base station controller in response to the measurement control message; In the general-purpose mobile communication system, the base station controller activates the IPDL of the reference base station and the IPDL of the neighboring base station which has transmitted the received signal to the mobile communication terminal among the neighboring base stations based on the measured value. How to operate IPPD of The method of claim 1, wherein the base station controller, After activating the IPDEL, transmitting the measurement control message to the mobile communication terminal and receiving the measurement report message from the mobile communication terminal. How El Works The location of the mobile communication terminal using a time difference between a reference base station located in a reference cell included in the mobile communication terminal and a received signal received from the neighbor base station located in at least one adjacent cell adjacent to the reference cell to the mobile communication terminal. In the general-purpose mobile communication system for identifying a, in the case where the location of the mobile communication terminal is not known, the method for preventing the overlap of the IPDL of the reference base station and the IPDL of one neighboring base station of the neighboring base station, Checking a state of IPDL of the reference base station and the neighboring base station, If the state of the IPDL of the reference base station or the neighboring base station is inactive, the reference to activate the IPDL of the reference base station or the neighboring base station where the IPDL is inactive and the reference to activate the IPDL And a step of setting an IP offset for performing IP synchronization between a plurality of sectors in the base station or the neighboring base station. delete delete delete

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