KR100821171B1 - Mobility Management Method of Mobile Terminal in Wideband Code Division Multiple Access System - Google Patents

Abstract

The present invention provides a method of managing mobility of a mobile terminal in a wideband code division multiple access (WCDMA) system, the method comprising: (a) a mobile resource in which a radio resource control (RRC) state is a cell paging channel (PCH) state; Receiving a cell update message including best cell information from a terminal, wherein the best cell means a cell having the largest signal strength received by the mobile terminal; (b) comparing the number of reception of the cell update message with a preset counter threshold value; (c) transitioning the RRC state of the mobile terminal to a Universal Terrestrial Radio Access Network (UTRAN) registration area (UTRAN) PCH state when the cell update message reception count is greater than or equal to the counter threshold value. ; And (d) transmitting a cell update acknowledgment message including the transitioned URA PCH state information to the mobile terminal.

Description

A method for managing mobility of a mobile terminal in a wideband code division multiple access system {Method for the mobility management of user equipment (UE) in wideband code division multiple access (WCDMA) system}

1 is a state diagram illustrating an RRC state transition in accordance with the prior art.

2 is a flowchart illustrating a cell update procedure according to the prior art.

3 is a state diagram illustrating an RRC state transition in accordance with the present invention.

4 is a URA PCH state transition flowchart in accordance with the present invention.

5 is a block diagram showing the relationship between URA and Cell according to the present invention.

6 is a state diagram illustrating an RRC state transition in accordance with the present invention.

7 is a flowchart illustrating a URA PCH state transition in accordance with an embodiment of the present invention.

* Explanation of symbols on the main parts of the drawing

112: Cell PCH Status

114: URA PCH status

210: UE (User Equipment)

400: Universal Terrestrial Radio Access Network (UTRAN)

The present invention relates to mobility management of user equipment (UE) in a wideband code division multiple access (WCDMA) system, and more particularly, attempts for excessive cell update of a UE located in a cell boundary region. It relates to a mobility management method of the UE for efficient control.

The WCDMA network is mainly composed of a CN (Core Network), a Universal Terrestrial Radio Access Network (UTRAN), and a User Equipment (UE).

The UTRAN consists of one or more RNSs (Radio Network Sub_Systems), and one RNS is composed of one RNC (Radio Network and at least one base station NodeB).

In particular, the RRC (Radio Resource Control) layer of the RNC performs the mobility management function of the UE as well as the allocation, change and release of radio resources.

A mobility management function of the UE is possible from the RRC state (State) Management defined in the ^{RRC, 3GPP (3 rd Generation Partnership} Project) UE in each RRC state in the standard TS 25.331 (RRC (Radio Resource Control ) Protocol Specification) and The role and behavior of UTRAN is defined.

The RRC state is largely divided into an idle mode and a connected mode, and the connected mode includes a cell DCH state, a cell FACH state, a cell PCH state, and a URA PCH state.

The UTRAN manages the mobility of the UE in the UTRAN and controls the RRC state transition in order to efficiently perform Radio Resource Management (RRM).

In general, the UTRAN manages the location of the UE at a cell or UTRAN Registration Area (URA) level.

In particular, when there is no radio connection established in the UE, the UTRAN manages the RRC state of the UE as a Cell PCH state or a URA PCH state.

If the RRC state of the UE is the Cell PCH state, if the UE finds a cell that is detected to be stronger than the currently connected cell, the UE notifies the UTRAN of the change of the best cell through a cell update procedure.

On the other hand, when the RRC state of the UE is the URA PCH state, if the UE detects an URA different from the currently managed URA, the UE informs the UTRAN of the URA change through the URA update procedure.

However, conventionally, when a UE in a Cell PCH state is located in a cell boundary region, a method for effectively controlling a cell update procedure frequently performed whenever a best cell is changed is not provided.

In the following description, problems of the prior art will be described with reference to the drawings.

1 is a state diagram illustrating an RRC state transition according to the prior art.

As shown in FIG. 1, a radio resource control (RRC) state is largely classified into an idle mode 102 and a connected mode 106.

Idle mode 102 refers to a state in which the power of the UE is off or the UE does not have any wireless connection with the base station.

The connected mode 106 includes a Cell Dedicated Channel (DCH) state 108, a Cell Forward Access Channel (FACH) state 110, a Cell Paging Channel (PCH) state 112, and a URA PCH state 114.

The transition from idle mode 102 to connected mode 106 is via RRC connection establishment 116 or 120.

In contrast, the transition from connected mode 106 to dormant mode 102 is possible via RRC disconnection 118 or 122.

2 is a flowchart illustrating a cell update procedure in a CELL_PCH state according to the prior art.

As shown in FIG. 2, when the UE 210 in the Cell PCH state 112 is located in the cell boundary region, the UE 210 performs a cell update.

When the UE 210 moves exactly on a cell boundary region (hatched area in FIG. 2), the strength of the common pilot channel (CPICH, 206) signal from the first cell 202 and the second cell 204 The intensity of the common pilot channel 208 signal from s is measured to a similar level.

At this time, the UE 210 transmits a cell update message including the corresponding cell ID whenever the cell having the largest strength of the received pilot signal (hereinafter, referred to as a 'best cell') is changed. (Radio Network Controller: RNC, 220).

The radio network controller 220 changes the current location information of the UE 210 to the received cell ID and then transmits a cell update confirmation message to the UE 210.

However, since the UE 210 is located in the cell boundary region, the best cell may change frequently.

Accordingly, the cell update message transmission frequency of the UE 210 increases.

In the following description, a cell update procedure will be described with reference to the drawings.

The UE 210 in the Cell PCH state 112 uses a common pilot channel (hereinafter, referred to as “Neighboring Cell List”) information included in the System Information received from the UTRAN. The signal strength of the 'pilot' is measured.

Here, the system information may also include information about a threshold value used to determine the best cell.

In this case, it is assumed that the movement path of the UE 210 moves only within the cell boundary region, and the current best cell is the second cell 204.

If the UE 210 determines that the pilot signal received from the first cell 202 is stronger than the pilot signal strength received from the second cell 204 which is the current best cell (S232), the UE 210 includes the first cell ID. The update message is transmitted to the wireless network control station 220 (S234).

The wireless network controller 220 updates the current best cell of the UE 210 to the first cell 204 according to the received cell update message (S236), and then transmits a cell update confirmation message to the UE 210. .

If the UE 210 determines that the best cell is changed to the second cell 204 again (S240), the UE 210 transmits a cell update message including the second cell ID to the wireless network control station 220 (S242).

The radio network controller 220 changes the current best cell of the UE 210 to the second cell 244 (S244), and then transmits a cell update confirmation message to the UE 210.

That is, the UE 210 transmits a cell update message to the radio network controller 220 whenever the best cell is changed.

As a result, if the UE 210 of the Cell PCH state 112 is located at the cell boundary, frequent cell update procedures may be performed, which may increase the interference on the air interface and thus reduce the overall radio capacity.

In order to solve the problems of the prior art as described above, the present invention provides a method for managing mobility of a UE in a WCDMA system, the cell update message number information and the cell update message arrival time information received from the UE in the Cell PCH state It is an object of the present invention to provide a UE mobility management method that can efficiently control the excessive cell update procedure performed by transitioning the RRC state of the UE to the URA PCH state.

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

In order to achieve the above object, according to a preferred embodiment of the present invention, in a method for managing mobility of a mobile terminal in a wideband code division multiple access (WCDMA) system, (a) Receiving a cell update message including best cell information from a mobile terminal having an RRC (Radio Resource Control) state in a Cell Paging Channel (PCH) state, wherein the best cell has the largest signal strength received by the mobile terminal; Means a cell; (b) comparing the number of reception of the cell update message with a preset counter threshold value; (c) transitioning the RRC state of the mobile terminal to a Universal Terrestrial Radio Access Network (UTRAN) registration area (UTRAN) PCH state when the cell update message reception count is greater than or equal to the counter threshold value. ; And (d) transmitting a cell update acknowledgment message including the transitioned URA PCH state information to the mobile terminal.

According to another embodiment of the present invention, in a method for managing mobility of a mobile terminal in a wideband code division multiple access (WCDMA) system, (a) a radio resource control (RRC) state is Cell PCH Receiving a cell update message including best cell information from the mobile terminal in a paging channel state, wherein the best cell means a cell having the largest signal strength received by the mobile terminal; (b) adding the best cell information to a multi-cell list; (c) comparing the number of reception of the cell update message with a preset counter threshold value; (d) transitioning the RRC state of the mobile terminal to a multi-cell PCH state when the number of cell update messages received is greater than or equal to the counter threshold; And (e) transmitting a cell update acknowledgment message including the transitioned multi-cell PCH status information and the multi-cell list to the mobile terminal.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same components have the same number as much as possible even if displayed on different drawings. Hereinafter, a preferred embodiment of a mobility management method of a terminal in a WCDMA system according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a state diagram showing an RRC state transition according to an embodiment of the present invention.

As shown in FIG. 3, a radio resource control (RRC) state is largely divided into an idle mode 302 and a connected mode 306.

Here, the RRC transmits and receives a control message related to setup, reconfiguration, and release of a radio bearer between a WCDMA network and a mobile terminal (hereinafter, referred to as a user equipment (UE)). Signaling protocol for.

The RRC state defines the types of transport channels that can be used by the UE in the connected mode 306 and how to operate in each state.

Idle mode 302 is the power of the UE is off (Off) or Universal Terrestrial Radio Access Network (UTRAN)-where UTRAN refers to a network consisting of a base station (NodeB) and a Radio Network Controller (RNC) in a WCDMA system Means no radio and no wireless connection.

That is, in idle mode 302 the UTRAN does not have any available information about the UE location.

However, the UE location information in the idle mode 302 is a home location of a core network (hereinafter referred to as a core network (CN)) with an accuracy of a location area (LA) or a routing area (RA) according to the last location registered information. It may be maintained in a home location register (HLR) or a variable location register (VLR).

That is, in the idle mode 302, the UTRAN cannot know UE location information of a cell unit or a UTRAN Registration Area (URA) unit.

Here, the above-mentioned URA means an area covered by a plurality of cells, and is location information which can be known only inside the UTRAN.

In this case, it is obvious to those skilled in the art that the combination of the cells and the definition of the URA or the concept of using the concept of the URA in the system may be determined by the service provider.

However, when using URA according to the 3GPP standard, up to eight URAs can be allocated to one cell.

The UE may obtain URA information corresponding to the cell transmitting the BCH through system information block type 2 (SIB2) information included in a broadcasting channel (BCH) transmitted by the UTRAN.

That is, the SIB2 includes at least one piece of URA information associated with the cell.

If the UE moves to a new URA not included in the SIB2 in the URA_PCH state 314, a URA update message is sent to the UTRAN.

That is, the UTRAN manages the location of the UE in units of URA for the UE in the URA_PCH state 314.

The connected mode 306 includes a Cell Dedicated Channel (DCH) state 308, a Cell Forward Access Channel (FACH) state 310, a Cell Paging Channel (PCH) state 312 and a URA PCH state 314.

The transition from idle mode 302 to connected mode 306 is through RRC connection establishment 316 or 320.

Conversely, switching from connected mode 306 to dormant mode 302 is possible via RRC disconnection 318 or 322.

For example, if the UE requests a new call establishment via a random access channel (RACH) (eg, an RRC connection establishment request message), the RRC state transitions from the dormant state 304 to the Cell FACH state 310.

In this case, when the UTRAN allocates a dedicated resource to the UE through the FACH (eg, an RRC connection establishment response message) in the cell FACH state 310, the RRC state of the UE transitions to the cell DCH state 308. .

If the allocated dedicated resource is released by the UE or UTRAN, the RRC state transitions to the idle state 304.

In the following description, each state included in the connection mode 306 will be described in detail.

In general, the UE may establish a wireless connection through a common channel or a dedicated channel.

The wireless connection using the common channel (eg, FACH) is established when low bit rate data is transmitted between the UE and the UTRAN.

On the other hand, for services requiring high data speed and low delay, a dedicated channel may be established between the UE and the UTRAN.

That is, the Cell FACH state 310 is an RRC state used when transmitting low data or when the UTRAN transmits resource allocation information to the UE as described above.

Here, if a radio connection is established using the resource allocation information, the RRC state of the UE transitions to the Cell DCH state 308.

In particular, in the case of a handover, since the RRC connection establishment message for a new wireless connection may be transmitted through a preset wireless connection, the RRC state does not go directly through the cell FACH state 310 and is immediately dormant (304). Transition to Cell DCH State 308 at.

If there is no data to transmit in Cell FACH state 310 or Cell DCH state 308, the RRC state transitions to Cell PCH state 312 or URA PCH state 314.

Once the UE state transitions to Cell PCH state 312 or URA PCH state 314, the UE monitors the paging channel according to the Discontinuous Reception (DRX) cycles information received from the UTRAN.

In this case, when the UE receives a paging message through the paging channel, the UE transitions to the Cell FACH state 310 after transmitting a paging response message to the UTRAN using a random access channel (RACH).

In particular, in the URA PCH state 314, the UE periodically sends a Cell Update message to the UTRAN when there is no data to be transmitted in the Cell DCH state 308 or the Cell FACH state 310 as well as when the UE has high mobility. Used to avoid sending to.

In addition, the URA PCH state 314 may be used to release dedicated resources allocated to the UE.

In the Cell PCH state 312, the UTRAN may acquire location information of the UE at a cell level, and in the URA PCH state 314, may obtain the URA level.

In order to obtain cell level position accuracy in URA PCH state 314, the UE can by sending a paging response message for the paging message received from the UTRAN.

That is, the UTRAN may obtain cell location UE location information by using cell update information included in the paging response message.

As shown in FIG. 3, the present invention may provide a direct state transition from the Cell PCH state 312 to the URA PCH state 314 as compared to the prior art.

Reference numeral 300 shows a direct state transition from Cell PCH state 312 to URA PCH state 314.

In general, if a UE in Cell PCH state 312 is located at the cell boundary, it may send a frequent cell update message to the UTRAN.

This not only increases interference on the air interface but also provides a cause for reducing the air capacity of the UTRAN.

In contrast, a UE in URA PCH state 314 transmits less control messages per unit time to the UTRAN than a UE in Cell PCH state 312.

More specifically, a UE in URA PCH state 314 performs the URA update procedure only if the URA is changed.

That is, a UE in URA PCH state 314 causes less interference on the air interface.

In this case, the determination of the state transition is performed by the UTRAN using the information on the number of cell update messages received from the UE for a unit time, and the UTRAN performs an RRC Paging Type 1 message in the Cell PCH state 312. Can be used to provide transitioned state information to the UE.

Here, the RRC paging type 1 message is a UTRAN when there is no wireless connection established between the UE and the UTRAN, that is, when the UE is in one of the idle state 304, the Cell PCH state 312 and the URA PCH state 314. This is the message used by.

4 is a URA PCH state transition flowchart, in accordance with an embodiment of the present invention.

As shown in FIG. 4, the UE 410 transmits a cell update message including the best cell ID to the UTRAN 400 (S402).

When the receiver 430 of the UTRAN 400 receives the cell update message, the receiver 430 compares whether the RRC state of the UE 410 is the Cell PCH state 312 (S404).

In step 404, if the RRC state is the Cell PCH state 312, the UTRAN 400 determines whether the best cell of the UE 410 has been changed with reference to the received cell update message (S406).

As a result of determination, if the best cell is changed, it is checked whether the timer for transitioning the RRC state is enabled (S408).

Here, the initial setting of the timer is maintained in a disabled state, and the timer is activated when a cell update message relating to the change of the best cell is first received from the UE 410 in the Cell PCH state 312. Enable).

In step 408, if the timer is inactive, after activating the timer, a value of T (0) is stored (S410).

Here, T (0) means the time at which the timer is activated, and in general, T (N) indicates the time at which the N-th cell update message is received.

If the timer is activated, the UTRAN 400 increments the cell update counter Cell_Update_Cnt by 1 and stores T (Cell_Update_Cnt) in which the increased cell update counter is a key value in an internal database. (S412).

The UTRAN 400 compares whether the incremented cell update counter is greater than or equal to the counter threshold MaxCnt (S416).

As a result of the comparison, if the incremented cell update counter is greater than or equal to the counter threshold MaxCnt, it is compared whether T (Cell_Update_Cnt) minus T (Cell_Update_Cnt-MaxCnt) is smaller than the timer threshold MaxTime (S416). ).

As a result of comparison, if the RRC state of the UE 410 is changed from the Cell PCH state 312 to the URA PCH state 314 (S418), a cell update confirmation message including the transitioned RRC state is generated. (S420) Transmit to UE 410.

The counter threshold and the timer threshold are system parameters that can be changed and set by the UTRAN administrator.

In steps 404 to 420, if the following conditions are met, the UTRAN 400 waits for reception of a new cell update message from the UE 410.

i) When the current RRC state of the UE 410 is not the Cell PCH state 312 in step 404 described above.

ii) In step 406, when the best cell is not changed (for example, the UE 410 may transmit a periodic cell update message without changing the best cell).

iii) In step 414, the cell update counter is less than the counter threshold.

iv) In step 416, when T (Cell_Update_Cnt) minus T (Cell_Update_Cnt-MaxCnt) is greater than or equal to the timer threshold.

As described above, the present invention can efficiently transition the UE 410 which is the Cell PCH state 312 to the URA PCH state 314 using the counter threshold and the timer threshold.

5 is a block diagram showing the relationship between URA and Cell in the UTRAN according to the present invention.

As shown in FIG. 5, one URA includes a plurality of cells.

In addition, a particular cell may be included in a plurality of URAs.

For example, referring to FIG. 5, the first cell 510 is included in all of the first URA 502, the second URA 504, the third URA 506, and the fourth URA 508.

This means that a plurality of URAs can be allocated to cells 514 located in regions where URAs overlap.

The first cell 510 is a UE 410 in which both the first cell 510 and the second cell 512 are included in the first URA 502 to the fourth URA 508, and in the CELL PCH state 312. And when located at the boundary of the second cell 512 (see FIG. 2), the UE 410 performs a frequent cell update procedure as described in FIG. 2.

At this time, the UTRAN 400 counts the number of cell update messages received from the UE 410, and when the predetermined counter threshold is exceeded, the UTRAN 400 changes the RRC state of the UE 410 to the URA PCH state 314. Transition

Of course, since the UE 410 in the URA PCH state 314 performs a cell update procedure only when it moves to a new URA, it is possible to obtain an effect of reducing air interface interference.

However, in order for the UTRAN 400 to transmit a paging message to the UE 410 in the URA PCH state 314, the UE 410 must transmit a paging message to all cells included in the last-registered URA. have.

Also, if the UE 410 fails to receive the paging message—one cell may be included in a different URA so that the paging to the last registered URA may fail—the CN is defined in the UTRAN 400. The paging message must be resent to all URAs.

As a result, by transmitting the paging message to an unnecessary cell, there is a problem that not only increases the load on the UTRAN 400 and the UE 410 but also increases the interference on the air interface.

In order to solve this, according to another embodiment of the present invention, when the UTRAN 400 receives a cell update message for at least two cells from the UE 410 or more during a predetermined period, the UTRAN ( 400 stores all cell IDs (hereinafter, referred to as 'MultiCell Lists') of cell updates during the period, and transitions the RRC state of the UE 410 to the multi-cell PCH state.

Here, the multi-cell PCH state is an RRC state added according to the spirit disclosed by the present invention and is not included in the current 3GPP standard.

Details related to the transition to the multi-cell PCH state will be described in detail with reference to FIGS. 6 and 7.

UTRAN 400 transmits a cell update acknowledgment message to UE 410 that includes the fact of the transition to the multi-cell PCH state and the multi-cell list.

When the UE 410 recognizes the transition to the multi-cell PCH state, the UE 410 does not transmit a cell update message to the UTRAN 400 even if at least one of the cells included in the received multi-cell list is changed to a best cell. .

In particular, when the UTRAN 400 receives a paging message for a UE in a multi-cell PCH state from the CN, the UTRAN 400 transmits the received paging message only to a cell included in the multi-cell ID.

6 is a state diagram illustrating an RRC state transition in accordance with the present invention.

As shown in FIG. 6, the RRC state transition diagram according to the present invention further includes a multi-cell PCH state 600 in the connected mode 306, and the UE 410 in the Cell PCH state 312. ) May transition to the multi-cell PCH state 600 via the Cell FACH state 310.

This means that when the UTRAN 400 transitions to the multi-cell PCH state 600 for the UE 410 in the Cell PCH state 312, the UE (410) transmits the state transition fact and the multi-cell ID to the UE through a cell update confirmation message. 410).

At this time, the UTRAN 400 transitions the RRC state of the corresponding UE 410 to the Cell FACH state 310, and then transmits a cell update confirmation message in which the RRC state information is set to the multi-cell PCH state 600. Send to

When transmission of the cell update acknowledgment message is completed, the UTRAN 400 transitions the RRC state of the UE 410 from the Cell FACH state 310 to the multi-cell PCH state 600.

If the UE 410 in the multi-cell PCH state 600 determines that a cell not included in the multi-cell ID is a new best cell, the UE 410 sends a cell update message including the ID of the new best cell. Send to UTRAN 400.

At this time, the UTRAN 400 sets the received new best cell ID as the current best cell and transitions the RRC state of the UE 410 to the Cell FACH state 310.

In the transitioned Cell FACH state 310, the UTRAN 400 transmits a cell update acknowledgment message with the RRC state information set to the Cell PCH state 312 to the UE 410.

Thereafter, the UTRAN 400 transitions the RRC state of the UE 410 to the Cell PCH state 312.

7 is a URA PCH state transition flowchart according to one embodiment of the present invention.

As shown in FIG. 7, the UE 410 transmits a cell update message including the best cell ID to the UTRAN 400 (S702).

When the receiver 430 of the UTRAN 400 receives the cell update message, the receiver 430 compares whether the RRC state of the UE 410 is the Cell PCH state 312 (S704).

In step 404, if the RRC state is the Cell PCH state 312, the UTRAN 400 determines whether the best cell of the UE 410 has been changed (S706).

As a result of determination, if the best cell is changed, it is checked whether a timer for transitioning the RRC state is enabled (S708).

Here, the initial setting of the timer is maintained in a disabled state, and the timer is activated when a cell update message relating to the change of the best cell is first received from the UE 410 in the Cell PCH state 312. Enable).

In step 508, if the timer is inactive, after activating the timer, it stores a T (0) value (S710).

Here, T (0) means the time at which the timer is activated, and in general, T (N) indicates the time at which the N-th cell update message is received.

The UTRAN 400 stores the best cell ID included in the received cell update message in an internal database (S712).

At this time, the UTRAN 400 stores the best cell ID only when the best cell ID does not exist in an internal database.

The UTRAN 400 increments the cell update counter (Cell_Update_Cnt) by 1 and stores T (Cell_Update_Cnt) which sets the increased cell update counter as a key value (S714).

The UTRAN 400 compares whether the incremented cell update counter is greater than or equal to the counter threshold MaxCnt (S716).

As a result of the comparison, if the incremented cell update counter is greater than or equal to the counter threshold MaxCnt, it is compared whether T (Cell_Update_Cnt) minus T (Cell_Update_Cnt-MaxCnt) is smaller than the timer threshold MaxTime (S718). ).

As a result of comparison, if the RRC state of the UE 410 is changed from the Cell PCH state 312 to the multi-cell PCH state 600 (S720), at least two or more cell IDs (hereinafter, ' Cell ID list ') (S722).

A cell update confirmation message including the transitioned RRC state (multi-cell PCH state 600) and a cell ID list is generated (S724) and transmitted to the UE 410.

The counter threshold and the timer threshold may be system parameters that can be changed and set by the UTRAN administrator.

In steps 704 to 724, when the following conditions are met, the UTRAN 400 waits for reception of a new cell update message from the UE 410.

i) If the current RRC state of the UE 410 is not the Cell PCH state 312 in step 704 above.

ii) In step 706, when the best cell is not changed (e.g., the UE 410 may transmit a periodic cell update message without changing the best cell).

iii) In step 716, the cell update counter is less than a predetermined counter threshold.

iv) In step 718, when T (Cell_Update_Cnt) minus T (Cell_Update_Cnt-MaxCnt) is greater than or equal to a predetermined timer threshold.

As described above, the present invention can efficiently transition the RRC state of the UE 410, which is the Cell PCH state 312, to the multi-cell PCH state 600 by using the counter threshold value and the timer threshold value.

In particular, the UTRAN 400 provides the cell list corresponding to the multi-cell PCH state 600 to the UE 410, thereby effectively controlling the frequent cell update procedure.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes, and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

As described above, the present invention provides a method for managing mobility of a UE in a WCDMA system, wherein the UE uses the cell update message count information and the cell update message arrival time information received from the UE in a Cell PCH state to provide an RRC state of the UE. By transitioning to the URA PCH state, there is an advantage to provide a UE mobility management method that can efficiently control the excessive cell update procedure is performed.

Claims (12)

A method of managing mobility of a mobile terminal in a wideband code division multiple access (WCDMA) system, (a) receiving a cell update message including best cell information from a mobile terminal having a Radio Resource Control (RRC) state of a Cell Paging Channel (PCH) state, wherein the best cell is a signal strength received by the mobile terminal; Is the largest cell; (b) comparing the number of reception of the cell update message with a preset counter threshold value; (c) transitioning the RRC state of the mobile terminal to a Universal Terrestrial Radio Access Network (UTRAN) registration area (UTRAN) PCH state when the cell update message reception count is greater than or equal to the counter threshold value. ; And (d) sending a cell update confirmation message including the transitioned URA PCH status information to the mobile terminal; A mobility management method of a mobile terminal comprising a. The method of claim 1, In step (c), (c1) subtracting a reception time of a cell update message previously received by the counter threshold value from a recent cell update message reception time; (c2) determining whether the subtracted time exceeds a preset threshold time, And translating the RRC state of the mobile terminal to URA PCH when the subtracted time is less than the preset threshold time. The method of claim 2, Store the reception time of the cell update message as T (N), where N indicates an Nth received cell update message; The subtracted time is given by the following equation T (Cell_Update_Cnt) -T (Cell_Update_Cnt -MaxCnt) Wherein, Cell_Update_Cnt is the number of cell update messages received so far and MaxCnt is a counter threshold for determining an RRC state transition. delete The method of claim 2, If the subtracted time in (c2) is greater than or equal to the preset threshold time, A mobility management method of a mobile terminal using the RRC state transition performing the step (a). The method of claim 1, If the number of the cell update message received in step (c) is less than the counter threshold, A mobility management method of a mobile terminal using the RRC state transition performing the step (a). A method for managing mobility of a mobile terminal in a wideband code division multiple access (WCDMA) system, (a) receiving a cell update message including best cell information from the mobile terminal in which a radio resource control (RRC) state is a cell paging channel (PCH) state, wherein the best cell is a signal received by the mobile terminal Means the cell with the greatest intensity; (b) adding the best cell information to a multi-cell list; (c) comparing the number of reception of the cell update message with a preset counter threshold value; (d) when the comparison result indicates that the number of reception of the cell update message is greater than or equal to the counter threshold value, Transitioning an RRC state of the mobile terminal to a multi-cell PCH state; And (e) transmitting a cell update acknowledgment message including the transitioned multi-cell PCH status information and the multi-cell list to the mobile terminal; A mobility management method of a mobile terminal using the RRC state transition comprising a. The method of claim 7, wherein In step (d), (d1) subtracting a reception time of a cell update message previously received by the counter threshold value from a recent cell update message reception time; (d2) determining whether the subtracted time exceeds a preset threshold time, And translating the RRC state of the mobile terminal to a multi-cell PCH when the subtracted time is less than the preset threshold time. The method of claim 8, Store the reception time of the cell update message as T (N), where N indicates an Nth received cell update message; The subtracted time in the step (d1) is the following equation T (Cell_Update_Cnt) -T (Cell_Update_Cnt -MaxCnt) Wherein, Cell_Update_Cnt is the number of cell update messages received so far and MaxCnt is a counter threshold for determining an RRC state transition. delete The method of claim 7, wherein In step (c), when the number of reception of the cell update message is smaller than the counter threshold value, A mobility management method of a mobile terminal using the RRC state transition performing the step (a). The method of claim 7, wherein In the step (b), if the best cell information is not included in the multi-cell list, the mobility management method of the mobile terminal using the RRC state transition to add the best cell information to the multi-cell list.

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