JP2002369236A - Mobile communication terminal equipment, method for controlling position registration of mobile communication terminal equipment and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control frequency of a position registration. SOLUTION: A method for controlling the position registration of a mobile communication terminal equipment comprises a step of recording data indicating a cell ID informed of system information of the cell of own station at present to the 'cell ID' of own station entry which is to be processed in a position registration flag list 10; steps of recording data, indicating the number of peripheral cells informed of the system information of the cell of the own station at present in the 'number of effective peripheral cells', and recording information regarding the peripheral cell informed of the system information in a 'peripheral cell list'; and steps of storing data indicating 'on' for the 'positional registration presence or absence flag' of an entry, corresponding to the cell of the own station, if the position registration is conducted in the case of zone transfer, and recording a career of whether or not the position registration is conducted in the case of zone transfer. The method also comprises a step of thereafter, for example, changing a cell reselection reference by combining an offset corresponding to the 'position registration presence or absence flag', in the case of reselecting the cell for zone transfer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile communication terminal, a position registration control method and a program for the mobile communication terminal.

[0002]

2. Description of the Related Art For example, a mobile communication terminal such as a portable telephone selects a cell to be a local station from cells formed by a plurality of base stations, and communicates by transmitting and receiving radio signals. Here, W-CDMA (Wideband-Code Divi)
For example, a mobile communication terminal that supports a sion multiple access method periodically measures the reception level and quality of radio signals transmitted from its own station and neighboring cells during standby. At this time, settings related to measurement, such as specification of neighboring cells to be measured, are defined based on system information from the own station.

[0003] Such a mobile communication terminal compares the result of measurement with a predetermined cell reselection criterion, autonomously reselects a cell, shifts a zone in which it is located (zone shift), and switches its own station. Can be. The parameter group for defining the cell reselection criterion is reported to the mobile communication terminal by system information from the own station.

For example, 3GPP (3rd Generation Partn)
ership Project (TS) (Technical Specific)
ation) 25.304, the mobile communication terminal reselects a cell (ce) based on the measured values of the reception level and quality of the radio signal and the cell priority specified by the network.
ll reselection).

[0005] At this time, the mobile communication terminal may perform location registration based on system information of a cell newly set as its own station as a result of shifting to a zone by reselecting a cell. For example, an LAC (Location Area Code) which is an identification code of a location registration area to which a cell that is a source of zone transfer belongs
And the LAC of the location registration area to which the destination cell belongs
If is different, location registration must be performed. In the location registration, a mobile communication terminal transmits a location registration message to a cell serving as a local station, and a base station serving as a local station transmits an HLR (Home Location Register) or a VLR (Visi
It is fulfilled by accessing a database such as the tor location register.

[0006]

In the above prior art, a cell is reselected based on a measured value of a reception level or quality of a radio signal and a cell priority specified by a network. Therefore, for example, when a mobile communication terminal is located near a boundary between a plurality of cells having different LACs, the frequency of location registration may increase.

Here, during communication for location registration, the mobile communication terminal cannot receive an incoming call. For this reason, there has been a problem that if the frequency of location registration increases, missed calls frequently occur. In addition, there is a problem that the amount of operation for transmitting and receiving wireless signals increases due to communication for location registration, and power consumption increases.

The present invention has been made in view of the above situation, and provides a mobile communication terminal capable of appropriately controlling the frequency of location registration, a location registration control method and a program for the mobile communication terminal. The purpose is to:

[0009]

In order to achieve the above object, a mobile communication terminal according to a first aspect of the present invention selects a cell to be a local station from cells formed by a plurality of base stations. A mobile communication terminal that communicates by re-selecting a cell to be its own station and storing the history of location registration when moving to a zone, and applying a reference based on the stored history. And reselecting a cell to be a local station.

[0010] A mobile communication terminal according to a second aspect of the present invention has received and received information on its own cell and peripheral cells from a cell that is its own cell among cells formed by a plurality of base stations. A mobile communication terminal that performs a cell reselection process based on information, and a history of whether or not location registration was performed when reselecting a cell and shifting to a zone,
Based on the history specifying means for specifying each cell and the history of the location registration specified by the history specifying means, a criterion for reselecting a neighboring cell as its own station is specified, and the specified criterion is applied to re-select the cell. Reselection processing means for selecting,
It is characterized by the following.

[0011] The reselection processing means reselects a cell by weighting a measured value of a radio signal transmitted from the own station and a neighboring cell in accordance with a history of whether or not location registration has been performed. It is desirable.

[0012] The reselection processing means may perform weighting by combining a predetermined negative offset with a measured value of a radio signal transmitted from a neighboring cell having a history of location registration. desirable.

The history specifying means stores the information indicating the history of whether or not the location registration has been performed, in association with the code number of the spreading code used in each cell, to thereby determine whether the location registration has been performed. It is desirable to be able to specify the history of whether or not it is possible for each cell.

[0014] A location registration control method for a mobile communication terminal according to a third aspect of the present invention provides information on the local station and neighboring cells from a cell that is defined as a local station among cells formed by a plurality of base stations. A location registration control method for a mobile communication terminal that receives and performs a cell reselection process based on the received information, the method comprising the steps of: History, a history specifying step to specify for each cell, based on the history of location registration specified in the history specifying step, based on the criteria for reselecting neighboring cells as their own station, applying the defined criteria And a reselection processing step of reselecting a cell.

[0015] A program according to a fourth aspect of the present invention is a program for transmitting and receiving a radio signal to and from a computer functioning as a mobile communication terminal, so that a cell which is a local station among cells formed by each of a plurality of base stations. From, the communication process of receiving information about the own station and peripheral cells, and history of whether location registration was performed when reselecting a cell and shifting to a zone, a history specifying process of specifying for each cell, Based on the history of the location registration specified by the history specifying process, a criterion for reselecting a neighboring cell specified from the information received by the communication process as its own station is specified, and the specified criterion is applied to reselect the cell. And reselection processing for selection.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a mobile communication terminal according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing an example of a configuration of a mobile communication terminal 100 according to an embodiment of the present invention. As shown, the mobile communication terminal 100 includes a communication processing unit 1
, A storage unit 2, a processing control unit 3, and an input / output unit 4.

The communication processing unit 1 includes, for example, an antenna or an RF
(Radio Frequency) This is configured to include a signal processing circuit, a baseband signal processing circuit, and the like, and communicates by transmitting and receiving a radio signal to and from a base station included in a mobile communication network. For example, the communication processing unit 1
Is the Primary Scramble Code
A specific data string transmitted by a cell serving as the own station is separated and extracted using a spreading code called “Code”. Here, the primary scrambling code is individually assigned to each cell using the same frequency in the mobile communication system, and is set so that the same primary scrambling code is not used in neighboring cells. This allows a cell to be uniquely specified from the primary scramble code in a specific area. Each primary scramble code is “0” to “5”.
11 ".

The storage unit 2 stores, for example, an EEPROM (Electr
onically Erasable and Programmable Read Only Memor
y), an SRAM (Static Random Access Memory), and the like, and stores an operation program and data that define the operation of the processing control unit 3. The storage unit 2 stores, for example, EE
The PROM stores data constituting the position registration flag list 10 as shown in FIG.

The location registration flag list 10 stores information on the history of location registration performed when the mobile communication terminal 100 reselects a cell to be its own station and shifts to a zone. For example, the location registration flag list 10 has an individual entry for each “code number” field indicating the code number of the primary scramble code. Each entry has members such as “cell ID”, “valid peripheral cell number”, and “peripheral cell list”. Here, the “peripheral cell list” has an entry for storing information on, for example, 32 peripheral cells,
Data indicating the number of entries used effectively among these entries is stored in the “number of effective peripheral cells”.
“Cell ID” is an invalid cell I as initial data.
When a cell using the primary scramble code of the code number corresponding to each entry is received as its own station, valid data indicating the cell ID of the cell is stored.

Each entry of the "neighboring cell list" included in the location registration flag list 10 has data fields such as "primary scramble code number" and "location registration presence / absence flag". Here, the “primary scramble code number” is the mobile communication terminal 100
Stores data indicating a code number for specifying a primary scrambling code of a neighboring cell broadcast from a cell serving as its own station. Also, the "location registration presence / absence flag"
Stores flag data for identifying the history of whether or not location registration has been performed at the time of reselecting a cell specified by the code number of the primary scramble code as its own station. For example, "location registration presence / absence flag"
Stores data indicating “ON” when there is a history of location registration. On the other hand, "location registration presence / absence flag"
Is "OFF" if there is no history of location registration
Is stored. The initial data stored in the “location registration presence / absence flag” is data indicating “OFF”.

The processing control unit 3 includes, for example, a CPU (Central
The mobile communication terminal 100 is composed of a microprocessor or the like, such as a processing unit, and controls the operation of the mobile communication terminal 100 as a whole. For example, the processing control unit 3 executes an operation program (described later) stored in the storage unit 2 to control the operation of the communication processing unit 1 and store data in the storage unit 2, for example, so that the processing control unit 3 performs the processing shown in the flowchart of FIG. And a flag setting process shown in the flowchart of FIG.

The input / output unit 4 includes a keypad, a liquid crystal display, a speaker, a microphone, a light emitting diode, and the like, and provides a user interface to input or output various information.

Next, the configuration of a mobile communication system to which the mobile communication terminal 100 is applied will be described. FIG.
1 is a diagram illustrating an example of a configuration of a mobile communication system to which a mobile communication terminal 100 is applied. This mobile communication system is a system that enables communication by the mobile communication terminal 100 using, for example, the W-CDMA method or the like. As shown in FIG. 3, a plurality of base stations 101 ₁ , 101 ₂ ,
.., 101 _m (m is a natural number) and the mobile communication control station 102
Mobile communication network 11 configured by combining
0 is provided.

A plurality of base stations 101 _{1 to} 101 _m set up a radio channel by transmitting and receiving a radio signal to and from mobile communication terminal 100 by at least one of the base stations. Each of the base stations 101 _{1 to} 101 _m is installed in each of a plurality of cells for enabling communication by the mobile communication terminal 100, and provides a mobile communication service with an area covered by each cell as a communication service area. .

Each of the base stations 101 _{1 to} 101 _m has an individually assigned cell ID. Cell ID, for example PLMN is unique value for each mobile communication network 110, such as (Public Land Mobile Network) are assigned without overlapping with respect to each base station ₁₀₁ 1 to 101 _m, the base stations ₁₀₁ 1 to 101 _m can be identified. Each base station 101 _{1 to} 101 _m has its own cell ID.
To the mobile communication terminal 100 using system information. In addition, each of the base stations 101 _{1 to} 101 _m transmits, to the mobile communication terminal 100, information on neighboring cells whose radio signal reception level or quality is to be measured for reselection of a cell to be a local station, by using system information. Mobile communication terminal 100
To inform. That is, each of the base stations 101 _{1 to} 101 _1
m notifies the mobile communication terminal 100 of the code number of the primary scramble code used in the neighboring cell by using system information.

The mobile communication control station 102 is for providing a wireless communication line for a mobile body, and includes a plurality of base stations 1.
01 _{1 to} 101 _m in a wired or wireless manner.
Further, the mobile communication control station 102 is coupled to a public line, another mobile communication system, or the like, and enables communication between the mobile communication terminal 100 and another communication device.

The operation of mobile communication terminal 100 according to the embodiment of the present invention will be described below. This mobile communication terminal 100 has a location registration flag list 1 as shown in FIG.
0 is stored in the storage unit 2, and the frequency of location registration is controlled by setting a criterion for reselecting a cell to be a local station based on the history of location registration performed in the past. be able to.

First, when the mobile communication terminal 100 is shipped,
When an all clear instruction is input from a key input unit (not shown) provided in the input / output unit 4, the position registration flag list 10 is initialized with predetermined initial data. For example, the “cell ID” of all entries corresponding to the “code number” in the position registration flag list 10 is initialized by initial data indicating an invalid cell ID.

Thereafter, when the mobile communication terminal 100 is turned on for transmitting and receiving radio signals to and from the base stations 101 _{1 to} 101 _m for communication, the processing control unit 3 sets the communication processing unit 1 Performs a process for transmitting and receiving a wireless signal. As a result, a cell to be a local station is selected from cells formed by the plurality of base stations 101 _{1 to} 101 _m , and system information including information on the local station and neighboring cells is received.

When the mobile communication terminal 100 returns to the communication service area or transitions to the standby state after the communication is completed, the mobile communication terminal 100 determines the cell of its own station as a standby destination in the flowchart of FIG. The flag list update processing shown in FIG. The process control unit 3 starts the execution of the flag list update process by executing the operation program stored in the storage unit 2.

When the flag list updating process is started, the process control unit 3 uses the code number of the primary scramble code used in the cell waiting as its own station to execute the entry (the entry to be processed) in the location registration flag list 10 (FIG. Hereinafter, referred to as "own station entry") (step S1).

The processing control section 3 determines whether or not the cell ID stored in the "cell ID" in the own station entry is a valid cell ID (step S2). Here, the “cell ID” of the location registration flag list 10 indicates data indicating an invalid cell ID, which is initial data, when the primary scramble code having the corresponding code number is not used in a cell where the primary scramble code is used. I remember.

When the processing control unit 3 determines that the cell ID is invalid (NO in step S2), the cell notified by the system information of the cell which is currently the own station is added to the "cell ID" in the own station entry. Data indicating the ID is recorded (step S3). After that, the processing control unit 3 records data indicating the number of neighboring cells reported by the system information of the cell that is currently serving as the "valid peripheral cell number" in the entry of the own station (step S4). In the "cell list", information on the neighboring cells notified by the system information of the cell which is the current station is recorded (step S5). That is, the data indicating the code number of the primary scramble code used in the neighboring cell group notified by the system information is recorded in the “primary scramble code number”, and “O” is set in the “location registration presence / absence flag”.
The initial data indicating "FF" is recorded.
The processing control unit 3 newly records information on the cell which is the local station in the local station entry.

On the other hand, the processing control section 3 executes the processing in step S2
When it is determined that the cell ID is a valid cell ID (step S
(YES at 2), it is determined whether or not the cell ID stored in the “cell ID” in the own station entry matches the cell ID reported by the system information of the cell that is currently the own station (step S6). ). Here, the “cell ID” of the location registration flag list 10 stores data indicating a valid cell ID when there is a history of waiting in a cell using the primary scramble code of the corresponding code number. However, if there is a history of waiting in a cell different from the cell currently serving as its own station, and the same primary scrambling code as the cell currently serving as its own station is used in the cell waiting in the past, the location registration flag Cell ID stored in "cell ID" of list 10
And the cell ID reported by the system information do not match.

When the processing control unit 3 determines that the cell IDs do not match (NO in step S6), the processing proceeds to step S3, and the data stored in the own station entry is changed to the cell currently used as the own station. Update to data on

On the other hand, when the processing control unit 3 determines that the cell IDs match (YES in step S6), the number of peripheral cells indicated by the data stored in the “valid peripheral cell number” in the own station entry is: It is determined whether or not the number of neighboring cells matches the number of neighboring cells reported by the system information of the cell currently serving as the own station (step S7). Here, even if there is a history of waiting in the past in the same cell as the cell that is currently serving as a local station, if the configuration of the neighboring cells changes after waiting in the past, the number of neighboring cells may also change. .

When the processing control unit 3 determines that the numbers of neighboring cells do not match (NO in step S7), the processing advances to step S4, and the data stored in the own station entry is set as the current own station. Update to cell data.

On the other hand, if the processing control unit 3 determines that the numbers of neighboring cells match (YES in step S7), the information stored in the "peripheral cell list" in the own station entry and the cell currently set as the own station are determined. Is compared with the information on the neighboring cell group notified by the system information (step S8). At this time, the processing control unit 3 matches the information on the neighboring cell group stored in the “peripheral cell list” in the entry of the own station with the information on the neighboring cell group notified by the system information of the cell which is currently the own station. It is determined whether or not it has been performed (step S9). That is, the processing control unit 3 sets the "neighboring cell list"
Whether the combination of the code numbers stored in the “primary scramble code number” in the above matches the combination of the code numbers broadcasted to identify the primary scramble code used in the neighboring cell group by the system information Is determined.

When the processing control unit 3 determines that the information on the peripheral cell group is not consistent (N in step S9)
O) The process proceeds to step S5, and the data stored in the own station entry is updated to data relating to the cell which is currently the own station.

On the other hand, if the processing control unit 3 determines that the information on the neighboring cell group is consistent (YES in step S9), it determines that there is no need to update the data stored in its own entry and sets a flag. The list update processing ends.

[0042] Thus, the base station 101 ₆ as shown in FIG. 5, for example if the wait for the local station, it is possible to create a location registration flag list 10 for storing data such as shown in FIG. Here, the base station 101 ₆ cells I
D is “532101” and the base stations 101 ₁ and 101
It is assumed that the cell having the number ₄ is a peripheral cell. In this example, the code number of the primary scrambling code the base station 101 ₁ is used is "012",
Code number of the primary scrambling code the base station 101 ₄ is used is "478", code number of the primary scrambling code the base station 101 ₆ uses is assumed to be "104".

[0043] In this case, the base station 101 _6, the system information, the cell ID "five hundred and thirty-two thousand one hundred and one " of its own station, two primary scrambling code of code number used by the peripheral cells "012", and "478", Notify the mobile communication terminal 100. Mobile communication terminal 100, based on the system information received from the base station 101 _6, by executing a flag list updating processing shown in the flowchart of FIG. 4 mentioned above, the location registration flag list 10 shown in FIG. 6 data Is stored in the storage unit 2.

Next, when the mobile communication terminal 100 executes the cell reselection process and shifts to the zone, the mobile communication terminal 100 sets the flag shown in the flowchart of FIG. While executing the list updating process, the flag setting process shown in the flowchart of FIG. 7 is executed for the source cell and the destination cell. less than,
The flag setting process shown in the flowchart of FIG. 7 will be described. The processing control unit 3 starts the flag setting process by executing the operation program stored in the storage unit 2.

When the flag setting process is started, the process control unit 3 sets an entry corresponding to a cell of the own station newly awaited as a transfer destination of the zone transfer (hereinafter referred to as “current own station entry”) and a zone transfer. An entry (hereinafter, referred to as “original station entry”) corresponding to the cell that has been waiting as a transfer source is determined (step S11). That is, the processing control unit 3 uses the location registration flag list 10 to determine the original entry of the own station corresponding to the code number of the primary scramble code used in the cell before the zone shift and the cell used as the own station after the zone shift. The current local station entry corresponding to the code number of the primary scramble code is determined.

The processing control unit 3 controls the mobile communication terminal 10
When 0 performs the cell reselection process and shifts to the zone,
It is determined whether or not position registration has been performed (step S1).
2).

When the processing control section 3 determines that the position registration has been performed (YES in step S12), the processing control section 3 updates the flag data stored in the "position registration presence / absence flag" of the position registration flag list 10 to update the flag data. The setting data D1 to be performed is held as data indicating “ON” (step S13).

On the other hand, when the processing control section 3 determines that the position registration has not been performed (NO in step S12), it holds the setting data D1 as data indicating "OFF" (step S14).

After that, the processing control unit 3 determines whether the “location registration presence / absence flag” of the entry corresponding to the cell currently serving as the own station in the “peripheral cell list” in the original own station entry or the above step S 13 or The setting data D1 defined in step S14 is stored (step S1
5). As a result, the history of whether or not the location registration was performed at the time of the zone transfer is recorded in the original own station entry.

Further, the processing control section 3 determines whether or not the source cell is included in the neighboring cells (step S1).
6). That is, the processing control unit 3 determines whether or not the information on the neighboring cells notified by the system information of the cell currently serving as the own station includes the information on the cell that is the transfer source of the zone transfer. More specifically,
The processing control unit 3 determines whether the code number of the primary scramble code used in the source cell is included in the code numbers broadcasted as the code numbers of the primary scramble codes used in the neighboring cells based on the system information. It is determined whether or not.

When the processing control unit 3 determines that the transfer source cell is included in the neighboring cells (YE in step S16).
S) In the “peripheral cell list” in the current own station entry, the “location registration presence / absence flag” of the entry corresponding to the cell of the transfer source is compared with the above step S13 or step S13.
The setting data D1 specified in 14 is stored (step S17). As a result, in the current own station entry,
A history of whether or not location registration was performed at the time of zone transfer is recorded.

On the other hand, when the processing control unit 3 determines that the source cell is not included in the neighboring cells (step S16).
NO), the process of step S17 is skipped, and the flag setting process ends.

In this way, information indicating whether or not location registration has been performed at the time of zone transfer is stored in the “location registration presence / absence flag”, and is used when executing cell reselection processing. The frequency of location registration can be reduced. For example, when the cell reselection process is executed, the mobile communication terminal 100 sets the history of whether or not the location registration has been performed for the reception level and the quality measurement value of the radio signal transmitted from the neighboring cell. By performing the corresponding weighting, the priority of the zone transfer to the cell where the location registration occurs can be reduced. Hereinafter, an example of a cell reselection process performed using information indicating whether or not the location registration has been performed will be described with reference to a zone shift determination process illustrated in a flowchart of FIG. This zone shift determination processing is started when the processing control unit 3 executes an operation program stored in the storage unit 2.

When the zone shift determination processing is started, the processing control section 3 compares the measured value of the radio signal transmitted from the cell serving as its own station with a predetermined threshold value and determines whether or not the measured value exceeds the threshold value. It is determined (step S21).

When the processing control section 3 determines that the measured value is equal to or less than the threshold value (NO in step S21), the processing advances to step S26, which will be described later, and executes processing for shifting to a zone in the same manner as in the related art. . That is, when the measured value of the radio signal transmitted from the cell as its own station is equal to or less than the threshold, the cell reselection process is executed regardless of the history of whether or not the location registration has been performed, and an appropriate cell is determined. It is possible to switch to the zone of the own station.

On the other hand, when the processing control unit 3 determines that the measured value exceeds the threshold value (YES in step S21),
A peripheral cell to be processed is set (step S2
2). The processing control unit 3 sets the flag data stored in the “location registration presence / absence flag” of the entry corresponding to the set peripheral cell to “O” in the location registration flag list 10.
N ”is determined (step S2).
3).

If the processing control section 3 determines that the signal indicates "ON" (YES in step S23), the processing control section 3 sets a predetermined value for the measured value of the radio signal transmitted from the peripheral cell to be processed. Combine negative offsets (step S
24).

On the other hand, the processing control section 3 sets the flag data to "
If it is determined that it indicates "OFF" (NO in step S23), the process in step S24 is skipped.
In this way, the processing control unit 3 sets the mobile communication terminal 10
0 assigns weight to the measured value of the reception level or quality of the radio signal transmitted from the neighboring cell in accordance with the history of whether or not the location registration has been performed.

Thereafter, the processing control section 3 determines whether or not the processing has been completed for all the neighboring cells (step S).
25) If it is determined that the processing has not been completed (step S25)
NO), the process returns to step S22, and the process is repeated with the remaining peripheral cells as processing targets.

On the other hand, when the processing control section 3 determines that the processing has been completed for all the peripheral cells (YES in step S25), the processing control section 3 determines whether or not to shift to the zone by the cell reselection processing similar to the conventional one. Is performed (step S26). That is, the measured values of the reception level and the quality of the radio signal obtained by combining the offsets of the specific neighboring cells in the processing of steps S21 to S25 are compared with a predetermined cell reselection criterion to determine the cell to be reselected. . As a result, the margin for zone transfer is increased for peripheral cells that require location registration at the time of zone transfer, and the cell priority when reselecting that cell is substantially reduced. That is, with respect to neighboring cells having a history of location registration, the cell reselection criteria are substantially changed to reduce the frequency of location registration. In this way, by reducing the frequency of zone transfer by reselecting neighboring cells for which location registration is performed,
The frequency of location registration can be appropriately controlled.

For example, conventionally, it is assumed that boundary lines L1 and L2 serving as zone transition points exist at positions as shown in FIG. 9A. Here, the boundary line L1 is formed of the mobile communication terminal 100 is a cell to its own station, a zone shift points for switching from a cell formed by the base station 101 ₁ to the cell formed by the base station 101 ₂ It is a boundary line. Also, the boundary line L2 is the mobile communication terminal 100
There a cell to its own station is a boundary line which is a zone transfer point for switching from a cell formed by the base station 101 ₂ to the cell formed by the base station 101 _1.
The cell formed by the base station 101 ₁ and the base station 1
01 when switching the cell to be self station is between ₂ cell formed by, it is assumed that the location registration is performed.

In this case, by applying the present invention, the positions of the boundary lines L1 and L2 are changed to the positions shown in FIG. Therefore, the base station 101
When mobile communication terminal 100 in the vicinity of the boundary between the cell formed by the cell and the base station 101 ₂ formed by ₁ is located, reducing the frequency of zone shift for switching the cell to the own station is executed Can be. This allows
It is possible to reduce the frequency of reselecting neighboring cells for which location registration is performed, and appropriately control the frequency of location registration.

As described above, according to the present invention,
Remember the history of location registration at the time of zone transfer,
By changing the cell reselection criterion based on the history, it is possible to appropriately control the frequency of location registration and reduce the frequency of reselecting neighboring cells for which location registration is performed. As a result, it is possible to prevent a missed incoming call from occurring as much as possible and reduce power consumption.

In the above embodiment, a case has been described where peripheral cells are specified by the code number of the primary scramble code. However, the present invention is not limited to this. That is,
The history of whether or not location registration has been performed using arbitrary information for specifying the neighboring cells is stored for each cell, and the cell reselection criteria are changed according to the history of location registration, etc.
The frequency of location registration may be controlled.

The present invention can be realized not only by a dedicated device but also by using a computer that operates as a normal mobile communication terminal. That is, an operation program for causing a computer functioning as a mobile communication terminal to execute each of the above-described processes is recorded in a predetermined recording unit, and a microprocessor such as a CPU reads and executes the operation program to execute the above-described operation. It can function as the mobile communication terminal 100. Here, the operation program is FD,
The program may be recorded on a computer-readable recording medium such as a CD-ROM, an MO, or an IC memory and distributed. In addition, FTP (File Trans
The operation program may be stored in a file system of a (fer Protocol) server or the like and downloaded to a computer, for example, by superimposing it on a carrier wave.

[0066]

According to the present invention, the frequency of location registration can be appropriately controlled.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a configuration of a mobile communication terminal according to an embodiment of the present invention.

FIG. 2 is a diagram showing a position registration flag list.

FIG. 3 is a diagram showing a mobile communication system to which a mobile communication terminal is applied.

FIG. 4 is a flowchart illustrating a flag list update process.

FIG. 5 is a diagram illustrating a specific example of an operation of updating a position registration flag list.

FIG. 6 is a diagram illustrating an example of a location registration flag list updated by a flag list update process.

FIG. 7 is a flowchart illustrating a flag setting process.

FIG. 8 is a flowchart illustrating a zone shift determination process.

FIG. 9 is a diagram for explaining a specific example of an operation of shifting to a zone.

[Explanation of symbols]

Reference Signs List 1 communication processing unit 2 storage unit 3 processing control unit 4 input / output unit 10 location registration flag list 100 mobile communication terminal 101 _{1 to} 101 _m base station 102 mobile communication control station 110 mobile communication network D1 setting data L1, L2 boundary line

Claims (7)

[Claims] 1. A mobile communication terminal for selecting and communicating with a cell to be a local station from cells formed by a plurality of base stations, and reselecting a cell to be a local station and shifting to a zone. A mobile communication terminal, wherein a history of location registration is stored in the mobile communication terminal, and a cell serving as a local station is reselected by applying a criterion based on the stored history. 2. A mobile station, which receives information on its own station and neighboring cells from a cell that is its own station among cells formed by each of a plurality of base stations, and executes a cell reselection process based on the received information. A mobile communication terminal, a history specifying means for specifying, for each cell, a history of whether or not location registration was performed when reselecting a cell and shifting to a zone, and a location registration specified by the history specifying means. And a reselection processing unit for reselecting a cell by reselecting a neighboring cell as its own station based on the history of the mobile communication terminal, and reselecting a cell by applying the defined criterion. 3. The reselection processing means performs weighting according to a history of whether or not location registration has been performed on a measured value of a radio signal transmitted from the own station and a neighboring cell to reselect a cell. The mobile communication terminal according to claim 2, wherein the mobile communication terminal is selected. 4. The reselection processing means weights a measured value of a radio signal transmitted from a neighboring cell having a history of location registration by synthesizing a predetermined negative offset. The mobile communication terminal according to claim 3, wherein: 5. The history specifying means stores information indicating a history of whether or not location registration has been performed in association with a code number of a spreading code used in each cell, thereby performing location registration. 5. The mobile communication terminal according to claim 2, wherein a history of whether or not the communication has been performed can be specified for each cell. 6. 6. A mobile station that receives information on its own cell and neighboring cells from a cell that is its own cell among cells formed by each of a plurality of base stations, and executes a cell reselection process based on the received information. A location registration control method for a mobile communication terminal, wherein a history of whether location registration has been performed when reselecting a cell and shifting to a zone, a history identification step of identifying each cell, and the history identification step. Based on the history of location registration specified in the above, defines a criterion for reselecting a neighboring cell as its own station, and comprises a reselection processing step of reselecting a cell by applying the defined criterion, Registration control method of a mobile communication terminal to be executed. 7. By transmitting and receiving a radio signal to and from a computer functioning as a mobile communication terminal, information on the own station and neighboring cells can be transmitted from a cell which is the own station among cells formed by each of the plurality of base stations. Communication processing to be received, the history of whether or not location registration was performed when reselecting a cell and shifting to a zone, a history identification process for identifying each cell, and a location registration identified by the history identification process Based on the history, defines a criterion for reselecting a neighboring cell specified from the information received by the communication process as the own station, and performs a reselection process of reselecting a cell by applying the defined criterion. Program for.