KR100821179B1 - Method and apparatus for generating monitored set in mobile telecommunication system - Google Patents

Abstract

A monitor target set generation method in a mobile communication system and a device are provided to configure a monitor target set by referring to neighbor lists of all cells which constitute an active set as well as a neighbor list of a primary cell, thereby improving a handover success rate. A neighbor list information manager(410) receives cell information of an active set and neighbor list information of cells from a base station controller. A monitor target set information generator(420) generates monitor target set information by using the cell information of the active set and the neighbor list information of the cells. A monitor target set information provider(430) provides the monitor target set information to a mobile communication terminal.

Description

METHOD AND APPARATUS FOR GENERATING MONITORED SET IN MOBILE TELECOMMUNICATION SYSTEM}

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view for explaining a conventional method for generating a set of monitor targets.

2 is a view for explaining a method for setting a set of monitor target according to an embodiment of the present invention.

3 is a diagram for describing an apparatus for generating a monitor target set according to an embodiment of the present invention.

4 is a block diagram illustrating an apparatus for generating a monitor target set according to an embodiment of the present invention.

5 and 6 are flowcharts of a method for generating a set of monitor targets according to an embodiment of the present invention.

7 to 9 are diagrams for explaining a method for generating a set of monitor targets according to an embodiment of the present invention.

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

100: mobile communication terminal 210: primary cell

310: first base station (node B) 320: second base station (node B)

330: base station controller (RNC) (RNC) 400: monitor target set generating device

410: Naver list information management unit 420: Monitor target set information generation unit

430: monitoring target set information providing unit

The present invention relates to a method and apparatus for generating a set of monitored targets in a mobile communication system, and more particularly, to a method and apparatus for generating a set of monitored targets for performing a handover by a mobile communication terminal.

The mobile communication system divides the entire service area into a plurality of base station areas and constitutes cells, which are small service areas, and centrally controls these base stations with a switching system, thereby allowing subscribers to move between cells while using mobile terminals. Ensure mobility to continue the call. In a mobile communication system, when a mobile terminal leaves a cell of a base station and enters a new cell, a call can be continued by a handover function.

Handover can vary in efficiency in terms of reliability of call continuity and system load, depending on the method and implementation. There are two major handover methods: soft handover and hard handover. Soft handover is a method of making a call before making a call, and hard handover is a method of cutting an arc before creating a new call. -before-make). When handover is required, the mobile communication system preferentially handles soft handover. However, if it is inevitable, hard handover ensures call continuity.

In order to perform the handover normally, the information on the cell that the terminal intends to proceed in the future should be precisely present in the cell that performs the current service. In a mobile communication network, such information is commonly referred to as a monitored set, and when the information is correctly registered, handover can be performed without any problem. Since the number of monitor target sets that can be registered in each cell is limited, it is necessary to perform optimization so that the limited monitor target set can include all movement paths.

1 is a view for explaining a conventional method for generating a set of monitor targets.

Referring to FIG. 1, the mobile communication terminal 100 measures pilot signal strengths from a plurality of cells 110 to 150 and sets an active set for handover.

In the conventional mobile communication system, when the mobile communication terminal 100 receives monitor target set information for handover, the neighbor list of primary cells having the strongest pilot signal strength in the active set is provided. For example, the neighbor list of primary cells is cells with Primary Scrambling Code (PSC) = 2, 4, 6, 8, 10, and the neighbor list of second rank cells is PSC = 2, 4, 5, If the cells are 7, 9, and the neighbor list of the third rank cell is PSC = 7, 8, 9, 10, 11, the set to be monitored is the neighbor list of the primary cell (PSC = 2, 4). , 6, 8, 10 cells, and PSC = 2, 4, 6, 8, 10 cells through the measurement control (Measurement Control) message to provide the monitoring target set information to the mobile communication terminal.

However, in the conventional method for generating a set of monitored targets, a neighbor cell having a higher priority of another active set than a neighbor cell having a lower priority among neighbor cells of a primary cell has a higher value as a monitored set. Although more likely, the large number of neighbor lists of primary cells may be excluded from the monitored target set.

For example, as shown in FIG. 1, the primary cell 110 at the location where the mobile communication terminal 100 is located has 32 neighbor lists. When the maximum size of the monitored target set that is notified to the mobile communication terminal 100 is 32, the PSC = 2 cell 160 which is a neighbor cell of PSC = 6 cells 130 which is another cell of the active set when viewed from the position of the mobile communication terminal 100 Although the PSC = 20 cell 150 or the PSC = 21 cell 140 is more suitable as a monitored target set, it is excluded from the monitored target set because it is not a neighbor list of primary cells.

The present invention has been made to solve the above problems, and an object of the present invention is to configure not only a neighbor list of primary cells, but also a primary cell when configuring a set of monitored targets for a mobile communication terminal in a traffic state. The present invention provides a method and apparatus for generating a set of monitored targets that can improve handover success rate by configuring a reference to a neighbor list of all cells constituting an active set.

It is still another object of the present invention to provide a method and apparatus for generating a set of monitor targets that can improve handover related system reliability by providing a more accurate set of monitor targets to a mobile communication terminal.

Other objects of the present invention will be readily understood through the following description.

According to an aspect of the present invention for achieving the above object, a method for setting a monitor target set for handover in a mobile communication system, the method comprising the steps of (a) aligning a cell set to an active set corresponding to the measured pilot channel strength (b) comparing a preset primary cell neighbor number of primary cells with a maximum size of the monitored target set among primary cells of the sorted active set, and (c) the primary cell neighbor If the number is smaller than a preset monitor target set maximum size, comparing whether the monitor target set maximum size is smaller than a product of the number of primary cell neighbors and the number of cells set as the active set; and (d) the comparison result. If small, monitor the top neighbor cells of the neighbor list of primary cells corresponding to the primary cell neighbor number Firstly setting a target set and (e) alternately setting upper neighbor cells of a neighbor list to the monitored target set for each of the other cells of the active set except for the primary cell by the number of primary cell neighbors. It may include.

According to another aspect of the present invention, a monitor target set setting device for handover in a mobile communication system comprises a neighbor list information management unit for receiving the cell information of the active set and the neighbor list information of the cell from the base station controller, the cell of the active set And a monitor target set information generator for generating monitor target set information using information and neighbor list information of the cell, and a monitor target set information providing unit for providing the monitor target set information to a mobile communication terminal.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and, unless expressly defined in this application, are construed in ideal or excessively formal meanings. It doesn't work.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be denoted by the same reference numerals regardless of the reference numerals and redundant description thereof will be omitted. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Hereinafter, the present invention can be applied to various mobile communication systems, such as, for example, a second generation communication system, and the following will mainly be described with an example of a WCDMA system.

2A and 2B are diagrams for describing a method for setting a monitor target set according to an exemplary embodiment of the present invention.

As shown in FIG. 2A, the cells corresponding to the active set to which the call is connected to the mobile communication terminal 100 are the A1 cell 210, the A2 cell 220, and the A3 cell 230. Here, the cell is an A1 cell 210 which is a primary cell, and NAi represents a neighbor cell of an Ai cell corresponding to an active set.

When setting the monitor target set to be notified to the mobile communication terminal 100 by a conventional method, the cell 222 that may be suitable as the monitor target set of the mobile communication terminal 100 among neighboring cells is the neighbor of the primary cell. Since it is not a cell, it may be excluded from the monitored target set of the mobile communication terminal 100.

However, according to the present invention, when configuring the monitored target set for the mobile communication terminal 100 in a traffic state, all the cells constituting the active set as well as the neighbor list of the primary cell, The success rate of handover can be improved by configuring the monitor target sets 212 to 218, 222 to 226, and 232 to 236 as shown in FIG. 2B with reference to the neighbor list of 220 and 230.

3 is a diagram illustrating an apparatus for generating a monitor target set according to an embodiment of the present invention.

The monitor target set providing apparatus 400 is coupled to the base station controller 330 in order to set the monitor target set necessary for the mobile communication terminal 100 to perform handover. It will be apparent to those skilled in the art that the monitor target set providing apparatus 400 may be implemented as part of the base station controller 330.

When the mobile communication terminal moves from the first cell 310 to the second cell 320 and performs handover, the mobile communication terminal 100 detects that the pilot signal update of the second cell exceeds a threshold. When a measurement report (MR) is transmitted to the base station controller (RNC) 330, and the base station controller (RNC) 330 analyzes the MR and information of the second cell, which is a target cell, exists in the monitored target set. Instructing the base station (Node B) 320 to allocate a channel, and after channel assignment is made, transmits an Active Set Update message to the mobile communication terminal 100. Thereafter, the mobile communication terminal 100 transmits an Active Set Update Completion message to the base station controller (RNC) 330 to complete the handover process.

When the monitor target set generation device 400 needs to notify the monitor target set from the base station controller (RNC) 330 to the mobile communication terminal 100, the neighbor list of cells of the active set set through the pilot channel strength measurement is combined. The set of monitored targets is provided to the mobile communication terminal 100 through the base station controller (RNC) 330.

When the number of primary cell neighbors of the active set is larger than the preset maximum size of the monitored target set, the apparatus 400 for generating a target set generation generates a monitored target set by listing the neighbor list of the primary cells. Here, the number of primary cell neighbors is the minimum number of neighbor list of primary cells to be guaranteed by the set to be monitored. For example, in a mobile communication system, an active set includes three cells, and a neighbor list of primary cells is a primary scrambling code (PSC) = 2, 4, 6, 8, 10, 12, and 14 The neighbor list of the second rank cell is PSC = 2, 4, 5, 7, 9, 12, 18, 20, and the neighbor list of the third rank cell is PSC = 7, 8, 9, 10, 11, Assume that cells are 14 and 15. If the pilot channel strength (the strength of CPICH Ec / No) is the primary cell neighbor number in the order of primary cell> second rank cell> third rank cell, If the maximum monitored target set size (maxCompoundingListSize) is 6, the monitored target set is generated to be composed of cells corresponding to PSC = 2, 4, 6, 8, 10, and 12, and is moved through the base station controller (RNC) 330. Provided to the communication terminal 100.

In addition, the monitor target set generating device 400 has a number of primary cell neighbors of the active set smaller than the preset monitor target set maximum size, and the monitor target set maximum size is larger than the number of primary cell neighbors × active set cells. If large, first, the neighbor cell of the primary cell is set to the priority of the monitored target set of the mobile communication terminal 100 by the number of primary cell neighbors, and the primary cell of the active set is next in the monitored target set. For each of the remaining cells except for the cell, the pilot cell strength is increased from the corresponding neighbor list upper neighbor cell one by one, and the number of primary cell neighbors is alternately set. Then, the next rank of the set to be monitored alternates one by one from the highest pilot channel strength among all the cells of the active set including the primary cell to the unset neighbor cells in the corresponding neighbor list. Create a set of monitored targets by listing them. For example, the active set consists of three cells, the neighbor list of primary cells is PSC = 2, 4, 6, 8, 10, and the neighbor list of the second rank cell is PSC = 2, The cells of 4, 5, 7, 9, 12, 18, and 20, and the neighbor list of the third rank cell are cells of PSC = 7, 8, 9, 10, 11, 14, and 15. The monitor target set generating apparatus 400 monitors if the number of neighbor cells of the primary cell having the highest pilot channel strength (the strength of CPICH Ec / No) is 3 and the monitor target set maximum size (maxCompoundingListSize) is 10. The target set is generated to be composed of cells corresponding to PSC = 2, 4, 6, 5, 7, 9, 8, 12, 10, 18, and the mobile communication terminal 100 through the base station controller (RNC) 330. To provide. This will be described in more detail with reference to FIGS. 4 to 9.

 4 is a block diagram illustrating an apparatus for generating a monitor target set according to an embodiment of the present invention.

The monitor target set generating apparatus 400 is combined with a base station controller (RNC) 330 to provide monitor target set information for handover to the mobile communication terminal 100. The monitor target set generating apparatus 150 may include a neighbor list information storage unit 410 for storing neighbor list information of a cell, and a monitor target set setting unit for setting a monitored target set using neighbor list information of a cell set as an active set ( 420, the monitor target set information providing unit 430 for providing the set monitor target set to the mobile communication terminal through the base station controller (RNC).

The neighbor list information manager 410 receives cell information of an active set and neighbor list information of a cell from a base station controller. The neighbor list information of the cell may be set in advance, and may be continuously updated using statistical information such as handover success rate after performing handover in cooperation with the base station controller (RNC) 330. The neighbor list information manager 410 may receive active set information of the mobile communication terminal 120 from the base station controller (RNC) 330 at predetermined intervals.

The monitor target set generator 420 generates monitor target set information by using cell information of the active set and neighbor list information of the cell. The monitor target set generation unit 420 may improve the handover success rate by setting the monitor target set with reference to the neighbor list of all cells set as the active set for the mobile communication terminal 100 in the traffic state.

The monitor target set generation unit 420 determines a combination method of the neighbor list of cells set in the active set by comparing the preset number of primary cell neighbors and the maximum size of the target monitor set.

The monitor target set generation unit 420 uses the cell information set as the active set and arranges them into primary cells, second rank cells, third rank cells, and the like in the order of pilot channel strength. Here, the pilot channel strength may be determined as Energy of Chips / Noise of Others (EC / No) of the Common Pilot Channel (CPICH).

If the number of primary cell neighbors of the preset active set is greater than the maximum size of the monitor target set, the monitor target set generation unit 420 sets the upper cells of the neighbor list of primary cells as many as the number of primary cell neighbors. do. Here, the number of primary cell neighbors is the minimum number of neighbor list of primary cells to be guaranteed by the set to be monitored, and may vary according to handoff related statistical information.

However, if the number of primary cell neighbors of the active set is smaller than the maximum size of the monitored target set, the monitored target set setting unit 420 preferentially monitors the upper set cells of the neighbor list of primary cells as many as the number of primary cell neighbors. The remaining monitor target set alternately sets upper cells of the neighbor list of other upper cells of the active set by the number of primary cell neighbors. Here, it is preferable to alternately set the upper cells of the neighbor list of other upper cells of the active set one by one, but the present invention is not limited thereto.

Finally, the monitor target set generation unit 420 alternately sets upper cells of each neighbor list of all cells set as the active set in the remaining number of monitor target sets. This will be described in more detail with reference to FIGS. 5 to 9.

The monitor target set information providing unit 430 provides the generated monitor target set to the mobile communication terminal 100 through a base station controller (RNC).

5 and 6 are flowcharts of a method for generating a set of monitor targets according to an embodiment of the present invention. 7 to 9 are diagrams for describing a method for generating a monitor target set according to an embodiment of the present invention.

In operation S510, the monitor target set generating apparatus 400 receives cell information set as an active set through pilot channel strength measurement from a base station controller (RNC) 330, and stores the primary cell in the order of the pilot channel strength. Sort by the second rank cell, the third rank cell and the like. As shown in FIG. 7, in the pilot channel strength order, all cells of the active set have a primary cell 710, a second rank cell 720, and a third rank cell having a neighbor list including seven cells. 730).

In operation S520, the monitor target set generating apparatus 400 compares the preset active set primary cell neighbor number #ofPrimaryCellNeighbor with the maximum monitor target set size MaxCompoundingListSize.

In operation S530, when the monitor target set generation device 400 determines that the preset number of active set primary cell neighbors (#ofPrimaryCellNeighbor) is greater than the maximum monitor target set size MaxCompoundingListSize, the primary cell neighbor number of primary cells is equal to the number of primary cell neighbors. Sets the top neighbor cells of the neighbor list of the target to be monitored. As described above, the number of primary cell neighbors is the minimum number of neighbor list of primary cells to be guaranteed by the set to be monitored, and may vary according to handoff related statistical information. For example, as illustrated in FIG. 7, the apparatus 400 for generating a monitored target set includes the number of primary cell neighbors (#ofPrimaryCellNeighbor) and the maximum size of the monitored target set (MaxCompoundingListSize) of 6. The top six neighbor cells of the neighbor list are set as the monitor target set.

In operation S540, the monitor target set generation device 400 may have a preset number of active set primary cell neighbors (#ofPrimaryCellNeighbor) smaller than the monitor target set maximum size (MaxCompoundingListSize), and the monitor target set maximum size (MaxCompoundingListSize) is (active set). It is determined whether the number is greater than the number of primary cell neighbors (#ofPrimaryCellNeighbor x number of cells set to the active set).

In operation S550, the monitor target set generation device 400 may have a predetermined number of active set primary cell neighbors (#ofPrimaryCellNeighbor) smaller than the monitor target set maximum size (MaxCompoundingListSize), and the maximum monitor target set size (MaxCompoundingListSize) is (active set). If the number of primary cell neighbors (#ofPrimaryCellNeighbor) x number of cells set to the active set) is greater than the number of primary cell neighbors, first, the upper neighbor cells of the neighbor list of primary cells are set as the monitored target set. For example, as shown in FIG. 8, the apparatus 400 for generating a target set monitor has a maximum target set size when the number of primary cell neighbors (#ofPrimaryCellNeighbor) is 4 and the maximum set target size MaxCompoundingListSize is 15. Since (MaxCompoundingListSize) is larger than (# ofPrimaryCellNeighbor) × number of cells set to the active set), the top neighbor cells of the neighbor list of primary cells are monitored as much as the number of primary cell neighbors. Set as a set (Neighbor # 1 to Neighbor # 4).

In operation S560, the monitor target set generating apparatus 400 sets the other neighbor cells of the active set except for the primary cell as the remaining ranks of the monitor target set one by one as many as the number of primary cell neighbors. For example, as illustrated in FIG. 8, the monitor target set generating apparatus 400 alternately sets upper neighbor cells of the neighbor list of other upper cells of the sorted active set to the remaining rank of the monitored target set (Neighbor). #a, Neighbor ##, Neighbor # b, Neighbor # ii, Neighbor # c, Neighbor ##, Neighbor # d, Neighbor ##. Here, it is preferable to set one of the upper cells of the neighbor list of the other upper cells of the active set alternately, but is not limited thereto. It is apparent to those skilled in the art that a plurality of alternating cells may be set alternately.

In operation S570, the monitor target set generating apparatus 400 alternates the top neighbor cells of the neighbor list of cells from the primary cell, which is the upper cell, to all the cells of the last sorted active set, one by one to the remaining monitored target set. Set it (Neighbor # 5, Neighbor # e, Neighbor # ⅴ).

In operation S580, the monitor target set generating device 400 provides the generated monitor target set to the mobile communication terminal 100 through the base station controller RNC.

Referring to FIG. 6, in operation S555, the monitor target set generating apparatus 400 may have a preset number of active set primary cell neighbors (#ofPrimaryCellNeighbor) smaller than the monitor target set maximum size MaxCompoundingListSize, and the monitor target set maximum size ( If MaxCompoundingListSize) is smaller than (# ofPrimaryCellNeighbor × number of cells set to the active set), first the top neighbor cells of the neighbor list of primary cells are monitored as much as the number of primary cell neighbors. Set to set. For example, as shown in FIG. 9, the monitor target set generating apparatus 400 has four primary cell neighbors (#ofPrimaryCellNeighbor) and eight monitor target set maximum sizes (MaxCompoundingListSize). Since (MaxCompoundingListSize) is smaller than (# ofPrimaryCellNeighbor) × number of cells set to the active set), priority is to monitor the top neighbor cells of the neighbor list of primary cells by the number of primary cell neighbors. Set as a set (Neighbor # 1 to Neighbor # 4).

In operation S565, the monitor target set generating apparatus 400 alternately ranks the upper neighbor cells of the neighbor list of other upper cells of the active set, excluding the primary cells by the number of primary cell neighbors, one by one, with the remaining rank of the monitored target set. Set it. For example, as illustrated in FIG. 9, the monitor target set generating apparatus 400 alternately sets the upper neighbor cells of the neighbor list of other upper cells of the sorted active set to the remaining rank of the monitored target set one by one ( Neighbor # a, Neighbor ##, Neighbor # b, Neighbor # ii, Neighbor # c, Neighbor ##, Neighbor # d, Neighbor ##.

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form.

As described above, according to the present invention, when configuring a monitored target set for a mobile communication terminal in a traffic state, not only the neighbor list of the primary cell, but also the neighbor list of all cells constituting the active set. By configuring with reference, the handover success rate can be improved.

The present invention has an effect of improving handover related system reliability by providing a more accurate set of monitor targets to a mobile communication terminal.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be appreciated that modifications and variations can be made.

Claims (14)

A method for setting a set of monitor targets for handover in a mobile communication system, (a) aligning cells set to the active set corresponding to the measured pilot channel strengths; (b) comparing a predetermined number of primary cell neighbors of a primary cell among the aligned active sets of cells with a number of cells of a maximum size monitor target set; (c) when the number of primary cell neighbors is smaller than a preset number of cells in the maximum size monitor target set as a result of the comparison, the number of cells in the maximum size monitor target set is set to the number of primary cell neighbors and the active set Comparing whether the number is less than the product of the numbers; (d) when the number of cells in the maximum size monitor target set is smaller than the product of the number of primary cell neighbors and the number of cells set as the active set, the number of cells in the neighbor list corresponding to the number of primary cell neighbors. Firstly setting an upper neighbor cell as a set of monitored targets; And and (e) alternately setting an upper neighbor cell of a neighbor list as a monitored target set for each of the other cells of the active set except for the primary cell by the number of primary cell neighbors. The method of claim 1, In step (d) If the number of cells of the maximum size monitor target set is larger than the product of the number of primary cell neighbors and the number of cells set to the active set, neighbor cells of each neighbor list of all cells of the active set after step (e). And setting the monitor target sets alternately one by one in the remaining ranks. The method of claim 1, And the number of primary cell neighbors is the number of cells in a minimum neighbor list of primary cells set to a preset monitor target set. The method of claim 1, Before step (a) above, And receiving Naver list information of all cells of the active set at predetermined intervals. The method of claim 1, And providing the set monitor target set information to a mobile communication terminal after the step (e). The method of claim 1, The monitor target set performs a handover so that a primary cell of the active set is changed, or a target cell of the active set is changed due to the addition, replacement, or removal of cells, or handover between frequency bands. Or when a measurement control message is transmitted after a handover failure between systems. The method of claim 1, Step (e) is And a plurality of upper neighbor cells of a neighbor list are alternately set as one or a plurality of monitor target sets by the number of primary cell neighbors. In the monitoring target set device for handover in a mobile communication system, A neighbor list information management unit which receives cell information of an active set and neighbor list information of the cell from a base station controller; A monitor target set information generation unit generating monitor target set information by using cell information of the active set and neighbor list information of the cell; And And a monitor target set information providing unit for providing the monitor target set information to a mobile communication terminal. The method of claim 8, The neighbor list information management unit performs a handover to change a primary cell of the active set or to change a target cell of the active set due to the addition, replacement, or removal of a cell, or a handset between frequency bands. And updating the neighbor list information when a measurement control message is transmitted after an over or a handover failure between systems. The method of claim 8, The monitor target set information generation unit Among the cells of the active set, the number of preset primary cell neighbors of primary cells is smaller than the maximum size of the monitored target set, and the maximum size of the monitored target set is set to the number of the primary cell neighbors and the active set. If less than the product of the number, the first neighbor cell of the neighbor cell list of the primary cell corresponding to the primary cell neighbor number is first set as a monitored target set, and then the other of the active set except the primary cell. And a plurality of upper neighbor cells of a neighbor list are alternately set as a monitored target set for each cell by the number of primary cell neighbors. The method of claim 8, The monitor target set information generation unit Among the cells of the active set, the number of preset primary cell neighbors of primary cells is smaller than the maximum size of the monitored target set, and the maximum size of the monitored target set is set to the number of the primary cell neighbors and the active set. If the number is multiplied by the number, the first neighbor cell of the neighbor list of the primary cell corresponding to the primary cell neighbor number is first set as a monitored target set, and then other cells of the active set except the primary cell are next set. For each of the primary cell neighbors, the upper neighbor cells of the neighbor list are alternately set to one monitor target set, and the remaining monitor target sets alternately set neighbor cells of each neighbor list of all cells of the active set. Monitor target set setting device . The method according to claim 10 or 11, wherein And the number of primary cell neighbors is the number of cells in a minimum neighbor list of primary cells set to a preset monitor target set. The method of claim 8, The monitor target set device is included as part of the base station controller of the mobile communication system or configured as a separate device to monitor the set target device, characterized in that the interlocking with the base station controller. A recording medium having recorded thereon a program readable by an electronic device which executes a method for setting a set of monitor targets for handover in a mobile communication system, (a) aligning cells set to the active set corresponding to the measured pilot channel strengths; (b) comparing a predetermined number of primary cell neighbors of a primary cell among the aligned active sets of cells with a number of cells of a maximum size monitor target set; (c) when the number of primary cell neighbors is smaller than a preset number of cells in the maximum size monitor target set as a result of the comparison, the number of cells in the maximum size monitor target set is set to the number of primary cell neighbors and the active set Comparing whether the number is less than the product of the numbers; (d) when the number of cells in the maximum size monitor target set is smaller than the product of the number of primary cell neighbors and the number of cells set as the active set, the number of cells in the neighbor list corresponding to the number of primary cell neighbors. Firstly setting an upper neighbor cell as a set of monitored targets; And  and (e) alternately setting the upper neighbor cells of the neighbor list as the monitored target set for each of the other cells of the active set except for the primary cells by the number of primary cell neighbors. Recording medium that records the program being executed.

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