JP2002247627A - Wireless network system and hand-over method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wireless network system that can conduct handover, even when a wireless channel with quality of the same degree to the channel quality of a wireless channel used at present cannot be set to the cell of a moving destination. SOLUTION: For example, when a mobile wireless IP packet terminal 1 making communication through the use of a wireless channel on a cell 3a moves an overlapped area between cells 3a and 3b and a channel with the same quality as that of a wireless channel on the cell 3a cannot be set to the moving destination cell 3b, a wireless access network controller 6 informs a service node 7 of the quality of a channel able to be set on the cell 3b, the service node 7 informs the mobile wireless IP packet terminal 1 about the degradation of the channel quality on the cell 3a, until the channel quality able to be set on the cell 3b and sets a wireless channel on the cell 3b by executing a prescribed handover procedure, after revising the channel quality on the cell 3a into the channel quality which can set on the cell 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio network system for realizing a handover in consideration of communication quality, and more particularly, to a radio network having a quality similar to that of a radio cell currently used for a destination cell. The present invention relates to a wireless network system capable of performing a handover even when the setting cannot be performed, and a handover method thereof.

[0002]

2. Description of the Related Art A conventional handover method will be described below. 3GPP Standard TR 25.931 (UTRAN
According to Functions, Examples on Signaling Procedures), in a conventional wireless network system, for example, a mobile wireless IP packet terminal (UE) that has performed communication using a wireless line on a certain cell is connected to the cell and another cell. When moving to the overlapping area of an adjacent cell, a handover process is performed if a line having the same quality as the line currently being used can be set for the destination cell.

[0003] That is, when a line of the same quality as that of the line currently used set on the source cell cannot be set in the target cell, the radio access network control device of the target cell is set in the destination cell. On the other hand, a "Radio Link Setup Failure" message indicating the reason is transmitted to notify that the line setting has failed.

[0004]

SUMMARY OF THE INVENTION However,
In the conventional wireless network system, if the above situation occurs, handover cannot be performed to a destination cell, and if the mobile wireless IP packet terminal continues to move, the wireless line will be disconnected soon. There was a problem. In such a case, the IP packet is lost, and there is a problem that the mobile wireless IP packet terminal needs to retransmit the IP packet.
In addition, when the wireless channel is set again after the disconnection, there is a problem that the communication session of the upper layer must be performed again.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and has been made in consideration of the above, and a radio network system capable of performing a handover even when a radio channel of the same quality as a radio channel currently used in a movement destination cell cannot be set. , And its handover method.

[0006]

Means for Solving the Problems The above-mentioned problems are solved,
In order to achieve the object, in a wireless network system according to the present invention, first line setting means (a wireless access network control device 6 and a wireless transmission / reception station 4a) for setting a wireless line for a first cell. Equivalent) and the first
Line setting means (corresponding to the radio access network control device 5 and the radio transmission / reception station 4b) for setting a radio channel for a second cell adjacent to the cell, and communication control means for controlling each line setting device (Equivalent to service node 7)
And a movable wireless IP packet terminal (corresponding to the mobile wireless IP packet terminal 1). For example, the wireless IP packet terminal communicating using a wireless line on the first cell is the first wireless IP packet terminal. Move to the overlap area of the cell and the second cell,
Despite the fact that the first line setting means has determined that it is necessary to perform handover from the first cell to the second cell, the destination second cell has the same function as the wireless line on the first cell. When a line of quality cannot be set, the first line setting means notifies the communication control means of the quality of a line that can be set on a second cell, and the communication control means Notifying the wireless IP packet terminal via the first line setting means that the line quality on the first cell is lowered to the line quality settable above, After changing the above line quality to a line quality that can be set on the second cell, a predetermined handover procedure is executed to set up a wireless line on the second cell.

In a wireless network system according to the next invention, the first line setting means includes a first wireless access network controller (corresponding to the wireless access network controller 6: SRNC) and a first wireless access network controller. A second transmitting / receiving station (corresponding to the radio transmitting / receiving station 4a: NodeB), wherein the second line setting means includes a second radio access network controller (corresponding to the radio access network controller 5: DRNC) and a second radio In the case where the first radio access network control device is configured by a transmitting / receiving station (corresponding to the radio transmitting / receiving station 4b: NodeB),
The second radio access network controller requests the second radio access network controller to set a line having the same quality as the line on the first cell, and the second radio access network controller transmits the second radio access network controller based on the setting request. A request for line setting is made to a radio transmitting / receiving station, and the second radio transmitting / receiving station determines whether or not the requested line quality can be obtained by referring to a resource management table held in an internal memory. If not, the second radio access network control device notifies the second radio access network control device of a line quality that can be set to a second cell, and the second radio access network control device
The first radio access network control device notifies the radio access network control device of the line quality that can be set to the second cell, and the first radio access network control device can set the communication control means on the second cell. Notifying the line quality, the communication control means transmits the wireless IP via the first wireless access network control device and the first wireless transmitting / receiving station.
Requesting the packet terminal to change the line quality on the first cell so as to have the same quality as the line quality settable on the second cell; The first radio access network controller again sets a line of the same quality as the line on the first cell to the second cell after the line quality is changed. It is characterized by doing.

In the wireless network system according to the next invention, the first line setting means is composed of a first wireless access network control device (SRNC) and a first wireless transmitting / receiving station (NodeB), In a case where the second line setting means is composed of a second radio access network control device (DRNC) and a second radio transmission / reception station (NodeB), the first radio access network control device is configured by The second radio access network controller requests the second radio access network controller to set a line having the same quality as the line on the first cell, and the second radio access network controller refers to a resource management table held in an internal memory. To determine whether the required line quality can be obtained, and if not, the first radio access network control device The first radio access network control device notifies the communication control means of the configurable line quality on the second cell, and The communication control means comprises: the first radio access network control device;
Requesting the wireless IP packet terminal to change the line quality on the first cell so as to have the same quality as the line quality settable on the second cell via the wireless transmitting / receiving station, The IP packet terminal notifies that a line quality that can be set on the second cell is accepted, and after the line quality is changed, the first radio access network control device again executes
A line having the same quality as the line on the first cell is set in the second cell.

[0009] In a handover method according to the next invention, a first radio access network controller (SRNC) and a first radio transmission / reception station (NodeB) for setting a radio channel for a first cell include: A second cell for setting a radio channel to a second cell adjacent to the first cell;
Radio access network controller (DRNC) and a second radio transceiver station (NodeB), and a service node (S) controlling each radio access network controller.
GSN) and a movable wireless IP packet terminal, the wireless IP packet terminal communicating using the wireless line on the first cell is connected to the first cell and the second cell. A first radio access network controller that requests the second radio access network controller to set a line of the same quality as a line on a first cell when the mobile station moves to a cell overlap area; A line setting requesting step, a second line setting requesting step in which the second radio access network control device requests a line setting to the second radio transmitting / receiving station based on the setting request; The radio transmitting and receiving station determines whether or not the requested line quality can be obtained by referring to the resource management table held in the internal memory. A first line quality notifying step of notifying a radio access network controller of the second cell of a line quality that can be set to a second cell, and the second radio access network controller being connected to the first radio access network controller. A second channel quality notifying step of notifying a second cell of a line quality that can be set to a second cell, and the first radio access network control device being able to set the service node on a second cell for the service node. A third line quality notifying step of notifying a line quality, the service node providing a second line quality notification to the wireless IP packet terminal via the first wireless access network control device and the first wireless transmitting / receiving station; A line quality change requesting step for requesting a change of the line quality on the first cell so as to be the same as the line quality settable on the cell , The wireless IP
A change permission notifying step of notifying that the packet terminal accepts a line quality that can be set on a second cell, and after the line quality is changed, the first radio access network control device again executes the second radio access A third line setting requesting step of requesting the network controller to set a line of the same quality as the line on the first cell.

[0010] In a handover method according to the next invention, a first radio access network control device (SRNC) and a first radio transmission / reception station (NodeB) for setting a radio channel for a first cell include: A second cell for setting a radio channel to a second cell adjacent to the first cell;
Radio access network controller (DRNC) and a second radio transceiver station (NodeB), and a service node (S) controlling each radio access network controller.
GSN) and a movable wireless IP packet terminal, the wireless IP packet terminal communicating using the wireless line on the first cell is connected to the first cell and the second cell. A first radio access network controller that requests the second radio access network controller to set a line of the same quality as a line on a first cell when the mobile station moves to a cell overlap area; A line setting requesting step, wherein the second radio access network control device determines whether or not the requested line quality can be obtained by referring to a resource management table held in an internal memory; A first line quality notifying step of notifying the first radio access network control device of a line quality that can be set to a second cell; A second line quality notifying step in which the line access network control device notifies the communication control unit of a line quality that can be set on a second cell; and the communication control unit controls the first radio access network control. Via the device and the first wireless transmitting / receiving station, the wireless IP packet terminal to change the line quality on the first cell so as to have the same quality as the line quality settable on the second cell. Requesting a line quality change request, a change permission notifying step of notifying that the wireless IP packet terminal accepts a line quality that can be set on a second cell, and the first wireless access network after changing the line quality. A second line setting for requesting the second radio access network control device again a line setting of the same quality as the line on the first cell; And determined step,
It is characterized by including.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a wireless network system and a handover method according to the present invention will be described in detail with reference to the drawings. The present invention is not limited by the embodiment.

Embodiment 1 FIG. 1 is a diagram showing a configuration of a wireless network system according to the present invention. Reference numeral 1 denotes a mobile wireless IP packet terminal (UE); 2a, a position before the mobile wireless IP packet terminal 1 moves; 2b, a position after the mobile wireless IP packet terminal 1 moves;
Is a wireless transmitting / receiving station (NodeB) of the cell 3a, and 4b
Is a radio transmission / reception station (NodeB) of the cell 3b, 5 is a radio access network control device (corresponding to the illustrated DRNC) for controlling the radio transmission / reception station 4b, and 6 is a radio access network control device for controlling the radio transmission / reception station 4a. A service node (corresponding to an SGSN) for controlling connection and communication between the radio access network controllers 5 and 6 and a gateway node 8 described later; 8 an external packet network such as the Internet 9 Gateway node (GGS
N).

Here, the operation of the wireless network system configured as described above will be described. FIG. 2 is a diagram illustrating a handover method according to the first embodiment. Here, a description will be given of a handover method when the mobile wireless IP packet terminal 1 moves from the position 2a to the position 2b which is an overlapping area of the cell 3a and the cell 3b during communication using a wireless line on the cell 3a. . In the present embodiment, it is assumed that each wireless transmitting / receiving station individually manages the quality of a line on a cell.

In the above case, first, the radio access network control device 6 adds a line to the cell 3b based on the quality measurement information and the like notified from the mobile radio IP packet terminal 1, and adds two radio lines. Is performed, and the activation of soft handover is determined here. Then, “Radiation” for requesting the wireless access network control device 5 for line setting is performed.
o Send a “Link Setup Request” message. "Radi
In the "Link Setup Request" message, the line information that has been set for the cell 3a is set, and the radio access network control device 5 is requested to set a line having the same quality as the set line on the cell 3a. .

Next, the radio access network controller 5 refers to the "Radio Link Setup Request" message received from the radio access network controller 6 and requests the radio transceiver station 4b for line setting. Radio Link Setup Request "message. The “Radio Link Setup Request” message contains
Here, the already set line information is set for the cell 3a.

Next, the radio transmitting / receiving station 4b receives the “Radio Li
From the "nk Setup Request" message, reference is made to the line information such as the bandwidth and line error rate requested for the setting. And
By referring to the resource management table held in the memory in the radio transmitting / receiving station 4b, it is determined whether or not the requested line quality can be obtained. FIG. 3 is a diagram illustrating an example of a resource management table managed by the wireless transmitting / receiving station. This resource management table describes information about communication resources, such as the remaining bandwidth and the current line error rate.

Here, as a result of the determination, if the requested line quality is not obtained, the radio transmitting / receiving station 4b notifies the radio access network control device 5 of the failure of the requested line setting. `` Radio Link Setup Fai
lure "message. This `` Radio Link Setup
In the “Failure” message, information such as the remaining bandwidth read from the resource management table and the current line error rate is set as line quality information.

Next, "Radio Li
The radio access network controller 5 that has received the “nk Setup Failure” message transmits a “Radio Link Setup Failure” message to notify the radio access network controller 6 of the failure of the requested line setup. In the "Radio Link Setup Failure" message, line quality information is set in the same manner as described above.

Next, upon receiving the "Radio Link Setup Failure" message, the radio access network controller 6 determines that the line quality on the cell 3a that has been set must be "reduced", and the service node 7
In response to a request to change the line quality (in this case, the line used by the mobile wireless IP packet terminal 1).
fy RAB QoS ”message. This "Modify RAB
The "Radio Link Setup" message
Line quality information included in the "Failure" message is set. That is, here, the line quality on the cell 3a is
Requests that the quality be reduced to that specified by the line quality information.

Next, the service node 7, which has received the "Modify RAB QoS" message, sends a "Modify PDP Context Request" message for requesting a reduction in communication quality to the radio access network controller 6, the radio transmitting / receiving station 4a. The packet is transmitted to the mobile wireless IP packet terminal 1 via This "Modify PDP Context Request"
In the message, line quality information included in the received “Modify RAB QoS” message is set.

Next, the mobile radio IP packet terminal 1 refers to the line quality information in the received "Modify PDP ContextRequest" message and, if there is no problem with the quality, notifies that the new line quality is to be accepted. A “Modify PDP Context Accept” message is transmitted to the service node 7 via the radio transmitting / receiving station 4a and the radio access network control device 6.

Next, "Modify PDP Context Accept"
In the service node 7 receiving the message (19), the mobile radio IP packet terminal 1, the radio transmitting / receiving station 4a,
And the wireless access network control device 6,
3GGP standard TS 23.060 (GPRS Service des
cription) “SGSN-Initiated PDP Con
`` Radio Access Bearer Modific '' of `` text Modification ''
ation "procedure to change the line on cell 3a to a new quality.

Next, after the line quality change processing on the cell 3a is completed, the radio access network control device 6 again sets a line of the same quality as the line on the cell 3a to the cell 3a.
A “Radio Link Setup Request” message for setting to “b” is transmitted to the wireless access network control device 5.

Here, since a line of the requested quality can be set on the cell 3b, a line setting is requested between the radio transmitting / receiving station 4b, the radio access network control device 5, and the radio access network control device 6. The normal procedure for exchanging the “Radio Link Setup Request” message to exchange the “Radio Link Setup Response”, which is a normal response message, is performed. After this procedure is completed, the wireless access network controller 6, the wireless access network controller 5, and the
GPP TR 25.931 (UTRAN Functions, Exampl
es on SignalingProcedure)
"ALCAP" and "DCH-F" of "Radio Link Addition of andover"
The lower layer line setting processing such as the "P" procedure is performed, and the line setting on the network side is completed.

Thereafter, the radio access network controller 6 sends an “Activate Set Update” message for notifying that the line on the cell 3b has been additionally set.
Mobile wireless IP packet terminal 1 via wireless transmitting / receiving station 4a
Send to In the “Activate Set Update” message, line information on the cell 3b newly added to the mobile wireless IP packet terminal 1 is set.

Finally, the mobile wireless IP packet terminal 1 sets the newly added cell 3b based on the line information in the received “Activate Set Update” message.
Activate so that the above line can be transmitted and received. And
Activate Set Update Comple indicating handover completion
A "te" message is transmitted to the wireless access network control device 6 via the wireless transmitting / receiving station 4a.

As described above, in the present embodiment, it is necessary for the wireless IP packet terminal 1 that is communicating using the wireless line on the cell 3a to move to the overlapping area of the cell 3a and the cell 3b and perform a handover. Even if it is determined that there is a line, if a line having the same quality as the wireless line on the cell 3a cannot be set in the destination cell 3b, the line quality on the cell 3a is reduced to the line quality that can be set on the cell 3b. After dropping, it is configured to request the setting of a wireless channel on the cell 3b again. As a result, handover can be performed even in the case where a wireless channel of the same quality as the currently used wireless channel cannot be set in the destination cell. Also,
In the present embodiment, since the resource management table is held in the internal memory of the radio transmitting / receiving station, it is possible to reliably determine whether or not the required line quality can be obtained.

Embodiment 2 In the present embodiment, a case where the mobile wireless IP packet terminal 1 moves from the position 2a to the position 2b which is an overlapping area of the cell 3a and the cell 3b during the communication using the wireless line on the cell 3a will be described. A handover method according to mode 2 will be described. FIG. 4 is a diagram illustrating a handover method according to the second embodiment. Note that, in the present embodiment, unlike Embodiment 1, it is assumed that each radio access network control device individually manages the quality of a line on a cell. Here, only operations different from those in the first embodiment will be described. Further, since the configuration of the wireless network system is the same as that of FIG. 1 in the first embodiment, the same reference numerals are given and the description is omitted.

First, the radio access network controller 6 adds a line to the cell 3b based on the quality measurement information notified from the mobile radio IP packet terminal 1 and the like, and diversity of data using two radio lines. The transfer is performed, and the activation of the soft handover is determined here. Then, a “Radio Link Setup Request” message is transmitted to the wireless access network control device 5.

Next, the radio access network controller 5 refers to the line information such as the bandwidth requested for setting and the line error rate from the “Radio Link Setup Request” message received from the radio access network controller 6. Then, by referring to the resource management table held in the memory in the wireless access network control device 5, it is determined whether or not the requested line quality can be obtained. FIG. 5 is a diagram illustrating an example of a resource management table managed by the wireless access network control device.
This resource management table describes the remaining bandwidths of all the radio transmission / reception stations controlled by one radio access network control device, the current line error rate, and the like.

If the requested line quality is not obtained as a result of the above determination, the radio access network controller 5 notifies the radio access network controller 6 of the failure of the requested line setting. Ra for
dio Link Setup Failure ”message. In this “Radio Link Setup Failure” message, information such as the remaining bandwidth read from the resource management table and the current line error rate is set as line quality information.

As described above, in the present embodiment, the same effects as those of the first embodiment can be obtained, and
Since the resource management table is held in the internal memory of the radio access network control device and it is determined whether or not the line quality requested by the radio access network control device can be obtained, the processing is carried out more than in the first embodiment. The amount can be reduced.

[0033]

As described above, according to the present invention, according to the present invention, the wireless I / O which is communicating using the wireless line on the first cell is provided.
Although the P packet terminal moves to the overlapping area of the first cell and the second cell, and it is determined that the handover needs to be performed, the P-cell terminal moves to the second cell of the movement destination by using the radio on the first cell. If a line of the same quality as the line cannot be set, the line quality on the first cell is reduced to a line quality that can be set on the second cell, and then the setting of the wireless line on the second cell is performed again. The required configuration was adopted. As a result, even when a wireless channel of the same quality as the currently used wireless channel quality cannot be set in the destination cell, it is possible to obtain a wireless network system capable of performing handover. Play.

According to the next invention, since the resource management table is held in the internal memory of the radio transmitting / receiving station, it is possible to reliably determine whether or not the required line quality can be obtained. There is an effect that a network system can be obtained.

According to the next invention, the resource management table is held in the internal memory of the radio access network controller, and it is determined whether the line quality requested by the radio access network controller can be obtained. Therefore, it is possible to obtain a wireless network system capable of greatly reducing the processing amount.

According to the next invention, the wireless IP packet terminal communicating using the wireless line on the first cell moves to the overlapping area of the first and second cells, and Even if a line having the same quality as the radio line on the first cell cannot be set in the second cell, the line quality on the first cell is set to the second line.
After dropping to the line quality that can be set on the cell of
It is requested to set up a wireless channel on the second cell.
As a result, there is an effect that a handover can be performed even when a wireless channel having the same quality as the currently used wireless channel quality cannot be set in the destination cell.

According to the next invention, the resource management table is held in the internal memory of the radio access network controller, and it is determined whether or not the line quality requested by the radio access network controller can be obtained. As a result, the processing amount can be significantly reduced,
This has the effect.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a wireless network system according to the present invention.

FIG. 2 is a diagram illustrating a handover method according to the first embodiment.

FIG. 3 is a diagram illustrating an example of a resource management table managed by a wireless transmitting / receiving station.

FIG. 4 is a diagram illustrating a handover method according to a second embodiment.

FIG. 5 is a diagram showing an example of a resource management table managed by the radio access network control device.

[Explanation of symbols]

1 Mobile wireless IP packet terminal (UE), 3a, 3b
Cell, 4a, 4b Radio transceiver station (NodeB), 5
Radio Access Network Controller (DRNC), 6
Radio Access Network Controller (SRNC), 7
Service Node (SGSN), 8 Gateway Node (GGSN).

Claims (5)

[Claims] 1. A first channel setting means for setting a radio channel for a first cell, and a second channel setting means adjacent to the first cell.
In a wireless network system comprising: a second line setting means for setting a wireless line for the cell, a communication control means for controlling each line setting means, and a mobile wireless IP packet terminal, The wireless I being communicating using a wireless line on the cell;
The P-packet terminal moves to the overlapping area of the first cell and the second cell, and the first line setting means transmits the second cell from the first cell to the second cell.
If a line of the same quality as the wireless line on the first cell cannot be set in the second cell of the movement destination even though it is determined that the handover needs to be performed to the cell, Notifies the communication control unit of the quality of the line that can be set on the second cell, and the communication control unit notifies the communication control unit of the line on the first cell until the line quality can be set on the second cell. Notifying the wireless IP packet terminal of a drop in quality via the first line setting means, and setting a line quality on the first cell on the second cell by a known method A wireless network system, wherein after a change to quality, a predetermined handover procedure is executed to set up a wireless channel on a second cell. 2. The first line setting means comprises a first radio access network control device (SRNC) and a first radio transmission / reception station (NodeB), and the second line setting means comprises a second radio access network controller (NodeB). When the first radio access network control device is configured by a second radio access network control device (DRNC) and a second radio transmission / reception station (NodeB), 1
Requesting a line setting of the same quality as the line on the cell, the second radio access network control device requests line setting to the second radio transmitting and receiving station based on the setting request, The second radio access network controller determines whether or not the requested line quality can be obtained by referring to a resource management table held in an internal memory. The second radio access network controller notifies the first radio access network controller of a second channel quality that can be set in the second cell.
The first radio access network control device notifies the communication control means of the configurable line quality on the second cell, and the communication control means A first radio access network control device, a first radio transceiver station, and a first radio transmission / reception station for the radio IP packet terminal so as to have the same channel quality as settable on a second cell. Requesting a change of the line quality on the cell, and notifying that the wireless IP packet terminal accepts a line quality that can be set on the second cell; and after changing the line quality, controlling the first radio access network. The wireless network system according to claim 1, wherein the device sets a line of the same quality as the line on the first cell again in the second cell. 3. The first line setting means comprises a first radio access network control device (SRNC) and a first radio transmission / reception station (NodeB), and the second line setting means comprises a second radio access network controller (NodeB). When the first radio access network control device is configured by a second radio access network control device (DRNC) and a second radio transmission / reception station (NodeB), 1
Requesting line setting of the same quality as the line on the cell, and determining whether the second radio access network controller can obtain the requested line quality by referring to a resource management table held in an internal memory. And if not obtained, notifies the first radio access network control device of a line quality that can be set to a second cell, and the first radio access network control device Notifying the unit of a line quality that can be set on a second cell, wherein the communication control unit transmits the wireless IP packet terminal via the first wireless access network control device and the first wireless transmission / reception station. Requesting that the line quality on the first cell be changed to be the same as the line quality that can be set on the second cell. After the line quality is changed, the first radio access network controller again changes the line of the same quality as the line on the first cell to the second cell. The wireless network system according to claim 1, wherein the setting is performed. 4. A first radio access network controller (SRNC) for setting up a radio channel for a first cell
And a first radio transmitting / receiving station (NodeB),
A second radio access network controller (DRN) for setting up a radio channel for a second cell adjacent to the second cell
C) and a second radio transceiver station (NodeB), a service node (SGSN) controlling each radio access network controller, and a mobile radio IP packet terminal.
The handover method when the wireless IP packet terminal communicating using the wireless line on the cell moves to the overlapping area of the first cell and the second cell; A first line setting requesting step in which a control device requests the second radio access network control device to set a line of the same quality as a line on a first cell; and wherein the second radio access network control device A second line setting requesting step of requesting a line setting to the second wireless transmitting / receiving station based on the setting request; and the second wireless transmitting / receiving station reads a resource management table held in an internal memory. It is determined whether or not the requested line quality can be obtained by referring to it. If not, it is possible to set the second radio access network control device in the second cell. A first line quality notifying step of notifying a proper line quality, and the second radio access network controller notifies the first radio access network controller of a line quality that can be set in a second cell. A second line quality notifying step; a third line quality notifying step in which the first radio access network controller notifies the service node of a line quality that can be set on a second cell; A node sends a signal to the wireless IP packet terminal via the first wireless access network control device and the first wireless transmitting / receiving station so that the quality is the same as the line quality that can be set on a second cell. A line quality change requesting step for requesting a change of the line quality on the first cell; and a line product that can be set on the second cell by the wireless IP packet terminal. And a change permission notifying step of notifying that the first radio access network controller has changed the line quality, and the second radio access network controller again transmits to the second radio access network controller a line on the first cell. A third line setting requesting step of requesting a line setting of the same quality. 5. A first radio access network controller (SRNC) for setting up a radio channel for a first cell
And a first radio transmitting / receiving station (NodeB),
A second radio access network controller (DRN) for setting a radio channel for a second cell adjacent to the second cell
C) and a second radio transmitting / receiving station (NodeB), a service node (SGSN) for controlling each radio access network control device, and a mobile radio IP packet terminal.
The handover method when the wireless IP packet terminal communicating using the wireless line on the cell moves to the overlapping area of the first cell and the second cell; A first line setting requesting step in which a control device requests the second radio access network control device to set a line of the same quality as a line on a first cell; and wherein the second radio access network control device It is determined whether or not the requested line quality is obtained by referring to a resource management table held in an internal memory. A first line quality notifying step of notifying a cell of a settable line quality; and a second radio access network control device instructing the communication control unit to perform a second line quality notification. A second line quality notifying step of notifying a line quality that can be set on a cell; and the communication control means transmits the wireless IP packet via the first wireless access network control device and the first wireless transmitting / receiving station. A line quality change requesting step for requesting the terminal to change the line quality on the first cell so as to have the same quality as the line quality settable on the second cell; A change permission notifying step of notifying that a line quality that can be set on the second cell is accepted, and after the line quality is changed, the first radio access network controller again transmits to the second radio access network controller the second radio access network controller. A second line setting requesting step for requesting a line setting of the same quality as the line on the first cell.