JP2003070054A - METHOD AND SYSTEM OF ASSURING QoS OF MOBILE NODE - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a method for assuring QoS of a mobile mode, by which the mobile node performs its hand-over operation. SOLUTION: The method includes a priority calculation step of detecting a hand-over mobile node and finding the priority of the hand-over mobile node and the priority of a mobile node in communication, in a cell of a mobile node as its hand-over destination with use of a database set in each mobile node, where the correspondence relation between a plurality of prioritized communication conditions and graded values of the communication conditions is set in each mobile node, on the basis of contract contents of each mobile node; a band allocation step of sequentially removing bands from the mobile node, having low priority according to the priorities for reallocating the bands; and a band assignment step of reassigning the bands to the hand-over node and mobile nodes, according to the band reassignment in the band assignment step.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and system for guaranteeing a QoS of a mobile node which is capable of securing a band in a cell of a handover destination by using a composite priority for a mobile node which is about to perform a handover. .

[0002]

2. Description of the Related Art Conventional mobile node QoS (Qua)
As a method of guaranteeing the "light of service", there is a "method of changing the property of communication service" disclosed in Japanese Patent Laid-Open No. 2000-209298. In this conventional technique, a plurality of service classes are set in which voice clarity, data transfer rate, error correction capability, etc. are changed stepwise. Then, the user selects the most suitable service class assuming his or her own service usage status, and also registers in the database whether or not the downgrade of the communication quality can be executed.
For example, in a mobile phone service, a user who has registered that the base station may access the database to reduce the quality of service when the system resource becomes small within the range covered by a certain base station. A user who executes a downgrade is selected from among the above, and the service class of the selected user is downgraded. As a result, the communication network resources are released, and it is possible to secure the communication network resources for the user who is making a new call at the base station. By doing so, instead of providing uniform service to all users, the quality of service can be changed according to the user's desire, and effective allocation of communication network resources can be performed. It was It was also possible to assign services to new users.

[0003]

However, in the method disclosed in Japanese Unexamined Patent Publication No. 2000-209298, the base station accesses the database to select or identify the user who executes the downgrade, The user who downgrades is selected based on the lowest priority user that has not been downgraded so far, but if there are many people with the same priority, there is no further selection criterion, ie However, there is a problem that a method for calculating a priority and selecting a user to be downgraded is not secured. Also,
When actually performing the downgrade, an alert is sent to the selected user for confirmation, and the user also responds to the alert, and when actually downgrading the class of service, the user is After the response from the side, an alert carrying the downgrade signal had to be sent, and the procedure for downgrading was complicated. In addition, CDMA (Co
de Division Multiple Access
For the situation such as the ss) method in which handover can be performed without interruption, the method is not described. Furthermore, in the current handover scheme,
If the destination line is congested or cannot take over the current line capacity, handover is not permitted, so the user either has not moved or has had to temporarily stop communication.

The present invention has been made in view of the above,
When a mobile node such as a mobile phone or a portable personal computer hands over from a cell to a cell adjacent to the cell, mapping is performed using the user information of the node belonging to the destination cell and the mobile node. A method and system for guaranteeing the QoS of a mobile node that guarantees the QoS of a mobile node performing a handover by controlling the bandwidth of a destination node according to the priority of the mobile node and reallocating the bandwidth. .

[0005]

In order to achieve the above object, a method of guaranteeing QoS of a mobile node according to the present invention detects a handover mobile node which is about to be handed over and a plurality of prioritized communication conditions and respective communication conditions. Communication is performed within the handover mobile node and the handover destination cell using a database in which the correspondence with the grade value for each communication condition is set for each mobile node based on the contract content of each mobile node. And a priority calculation step of obtaining the priority of each mobile node, and based on the calculated priority, when it is detected that a mobile node having a priority lower than that of the handover mobile node exists in the handover destination cell, , To ensure the minimum bandwidth specified in the contract As a band allocation step of redistributing bands by reducing the bands in order of priority from the mobile node having a low priority, and the handover mobile node according to the band reallocation in the band allocation step. And a band allocation step of reallocating a band to the mobile node.

According to the present invention, when a handover mobile node that is about to perform a handover is detected in the priority calculation step, a correspondence relationship between a plurality of prioritized communication conditions and a grade value for each communication condition is established for each mobile. Using the database set for each mobile node based on the contract contents of the node, the priority of each of the handover mobile node and the mobile node communicating in the handover destination cell is obtained. Next, when it is detected by the bandwidth allocation step that a mobile node having a priority lower than that of the handover mobile node exists in the cell of the handover destination based on the calculated priority, the contract content is defined. The bandwidth is redistributed by reducing the bandwidth in the order of the priority from the mobile node having a lower priority, on the condition that the allocated minimum bandwidth is secured. Then, in the band allocating step, the band is reallocated to the handover mobile node and the mobile node according to the reallocation of the band in the band allocating step.

Qo of the mobile node according to the next invention
In the above invention, the S guarantee method is the communication condition,
It is characterized in that it is a communication condition including two or more of a charge system, band, number of reductions, and data type.

According to the present invention, the communication conditions include two or more of a fee system, a band, a reduction count, and a data type. As a result, a finer priority can be calculated by combining a plurality of different communication conditions, and it is possible to eliminate bias in the nodes for which band reduction is performed.

Qo of the mobile node according to the next invention
In the above invention, the S guarantee method is characterized in that the contents of the database are updated according to the bandwidth of the mobile node reallocated in the bandwidth allocation step.

According to the present invention, the contents of the database are updated according to the band of the mobile node that has been reallocated by the band allocating step. As a result, the database has information of updated contents, and the priority can be calculated by referring to the communication condition having the latest contents.

Qo of the mobile node according to the next invention
In the above invention, the S guarantee method is the above invention, wherein in the priority calculation step, a sum of a plurality of communication condition products of a priority of each communication condition and a grade value of each mobile node set in each communication condition is calculated. It is characterized in that an evaluation function for calculating as a priority is used, and the priority for the handover mobile node and the mobile node is calculated by the evaluation function.

According to the present invention, in the priority calculation step, the sum of a plurality of communication condition products of the priority order of each communication condition and the grade value of each mobile node set in each communication condition is prioritized. An evaluation function for calculating the degree is used, and the priority of the handover mobile node and the priority of the mobile node are calculated by the evaluation function. Even if there are multiple communication conditions, and the communication conditions consist of multiple grades, the priority for each mobile node can be calculated, and each mobile node can be easily ranked. be able to.

Qo of the mobile node according to the next invention
The S guarantee system relates to a correspondence relationship between one to a plurality of radio access network control devices for controlling mobile nodes in a plurality of cells, a plurality of prioritized communication conditions, and a grade value for each communication condition. The mobile node comprises a database in which user information is set for each mobile node based on the contract content of each mobile node, and a service node for managing the radio access network control device, and the radio access network control device attempts to perform handover. When a handover mobile node that is present is detected, the user information regarding the handover mobile node and the mobile node communicating in the handover destination cell is received from the database via the service node, and based on the received user information. The hand Server mobile node and the priority of the mobile node respectively, and based on the calculated priority, when it is detected that there is a mobile node having a priority lower than the handover mobile node, the contract content On condition that the minimum bandwidth defined in the above is ensured, the bandwidth is redistributed by reducing the bandwidth in the order of priority from the mobile node having a low priority, and the redistributed bandwidth allocation information is A bandwidth allocating means for transmitting to the service node, wherein the service node updates information stored in the database according to bandwidth allocation information transmitted from the radio access network control device; According to the stored contents, the hand-on device is operated via the radio access network control device Characterized in that it comprises a band allocation means for allocating bandwidth to bar the mobile node and the mobile node, the.

According to the present invention, one to a plurality of radio access network control devices for controlling mobile nodes in a plurality of cells, a plurality of prioritized communication conditions, and a grade value for each communication condition. Provided is a mobile node QoS guarantee system including a database in which user information related to the correspondence relationship between the mobile nodes is set for each mobile node based on the contract content of each mobile node, and a service node that manages the radio access network control device. To be done. The radio access network control device comprises a band allocating means. When the band allocating means detects a handover mobile node that is about to perform handover, receives the user information regarding the handover mobile node and the mobile node communicating in the handover destination cell from the database via the service node, The priorities of the handover mobile node and the mobile node are respectively obtained based on the received user information, and it is detected that there is a mobile node having a priority lower than that of the handover mobile node based on the calculated priority. In that case, the bandwidth is redistributed by reducing the bandwidth in the order of priority from the mobile node having a low priority, provided that the minimum bandwidth defined in the contract content is secured. The re-allocated bandwidth allocation information is before It is sent to the service node. The service node includes an information updating unit and a band allocating unit. The information updating means updates the storage information of the database according to the band allocation information transmitted from the radio access network control device. Further, the band allocating unit allocates a band to the handover mobile node and the mobile node via the radio access network controller according to the stored contents of the updated database.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a mobile node QoS guarantee method and system according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of a system for executing the QoS guarantee method for a mobile node according to the present invention. In this figure, 1 is a gateway node (hereinafter referred to as GGSN) interconnecting with an external packet network 9 such as the Internet, and 2 is a position information / service information management system (hereinafter referred to as a position information / service information management system (hereinafter, referred to as GGSN) in which information such as a user's fee plan is held. , Called HLR)
3 is a service node (hereinafter, SG) that controls connection communication of a radio access network (hereinafter, RAN).
SN), 4 is a first radio access network control device (hereinafter referred to as SRNC) that sets a radio line for cells 8a and 8b, and 5 is a second radio access network control device that sets a radio line for cell 8c. A radio access network control device (hereinafter, referred to as DRNC), 6 is a radio access network control device (hereinafter, referred to as RNC) that sets a radio line to another cell, and 7a to 7c are node Bs.
8a to 8c are cells within the range covered by the Node Bs 7a to 7c, 9 is an external packet network, and 10 is a mobile node (MN) owned by the user.
11a to 11e respectively represent other mobile nodes owned by other users. Here, the node B means a base station or the like, and the mobile node 10,
Reference numerals 11a to 11e denote terminals used by users for wireless communication, such as mobile phones and PHSs (Personal Han).
dyphone system), PDA (Porta
ble Digital Assistants), portable personal computers and the like. RAN is S
RNC4, DRNC5, RNC6 and node B7a-
7c is a wireless access network. In addition, this FIG. 1 shows "3GPP (3rd G
energy Partnership Proj
ect) 99 ”.

(1) Complex Priority Calculation Method In the QoS guarantee system for a mobile node according to the present invention, a user who uses the wireless communication system as shown in FIG. 1 can use various service plans in advance. Is presented. For example, the fee is divided into several grades, and the user himself selects the fee service plan that best suits the user's preference. In this case, the priority of each grade is represented by a relative numerical value. FIG. 2 shows an example of the relationship between the fee system and its priority. Here, it is assumed that a higher communication rate provides a better communication environment with a wider band and better communication quality. And the most expensive plan (H
(High-Plan) with a high priority of 5, and the lowest rate plan (Low-Plan)
It has a low priority of 1. A priority of 3 is given to the middle plan (Middle-Plan). Of course, the number of stages may be two instead of three, and four or more stages may be provided. Any numerical value may be used as long as the priority of the grade is relatively expressed, and an arbitrary numerical value can be used. Further, the method of determining the fee system can be differentiated by providing not only the width of the band but also an option as to whether or not the band can be reduced when communication is crowded. In addition, when providing a service with a fixed data type,
For example, there may be a case where a fee is differentiated between a user who only uses voice communication and a user who wants to use voice communication and streaming video.

In addition, when the user uses the system, stages are set for communication conditions that are factors such as communication quality that can set levels in stages.
It is necessary to set the priority in advance. At this time, in order to calculate the composite priority, it is necessary to represent the priority with a relative numerical value for each communication condition stage. As shown in FIG. 2 to FIG. 5, examples of factors such as communication quality in which the level can be set in stages, that is, communication conditions include a charge, a band, a reduction frequency, and a data type. Also, priority is set between these communication conditions as shown in FIG. 6, and this is used as priority between user information. In the following, a set of communication conditions selected by a user from a plurality of communication conditions is also referred to as user information.

In the priority of each band in FIG. 3, 5 is assigned to the thinnest band, which is high priority, and 1 is assigned to the thickest band, which is low priority. Priority numbers 1 to 5 are attached. In FIG. 3, "thin or thick" for a band is to judge whether the band is thinner or thicker than the standard band based on the standard band determined by each charge system.

FIG. 4 shows an example of priorities for each reduction count. The number of times of reduction indicates the number of times the bandwidth has been reduced because the priority was low in the past. In the case of FIG. 4, 5 which is the highest priority is attached to the number of reductions of 2 or more,
If it has not been reduced in the past, the lowest priority of 1 is added. Then, during this period, the priority is determined by dividing it into stages by a number from 1 to 5.

FIG. 5 shows an example of priority for each data type. In the case of FIG. 5, the data types are, in descending order of priority, an emergency signal, conversational voice (Conversational voice), streaming video (Streaming Video),
Interactive Web,
Downloading data in the background (Back
It is the ground DataDownLoad). Conversational voice is traffic such as voice in telephone communication, and strict low delay is required, and retransmission is meaningless. Streaming video is data that requires low latency, though not as much as the conversational voice class, and retransmission makes little sense. The interactive web is traffic like web browsing, which is data that requires retention of data content. Downloading data in the background is done by FTP (F
For application traffic such as ile Transfer Protocol, it is necessary to retain the data content, but unlike other classes, there is no request for delay. Here, the highest priority 5 is assigned to the emergency signal, the lowest priority 1 is assigned to the data download in the background, and those in the middle are divided into several stages to 1 to 5. It is represented by numbers. Note that the data type in FIG. 5 uses the data type defined in “3GPPR99” for simplification of the model.

FIG. 6 shows an example of priorities of user information. The priority given here is an index of the priority among the user information, that is, the priority among the communication conditions forming the user information shown in FIGS. 2 to 5. In this embodiment, an example as shown in FIG. 6 is used for the evaluation function F (n) described later. That is, the charge system is given priority 7, the data type and veto right are given priority 5, the number of reductions and terminal types are given priority 3, and the current band, stay time and connection time are given priority 1. . Since this is an example, it is assumed that the priority is changed according to the service environment.

The above-mentioned FIGS. 2 to 6 are shown as examples for the sake of simplification of the model, and the priority stages and the like in each figure can be changed appropriately.
Further, the communication conditions used in the calculation of the composite priority are not limited to those shown in FIGS. 2 to 6, and other conditions can be used. That is, the communication conditions used for calculating the priority can be changed according to the situation. These are also the contract contents of each user.

Next, a method of calculating composite priorities will be described. In the present invention, a function for obtaining a composite priority is called an evaluation function, F (n)
It is represented by. Here, n indicates the mobile node name of the user.

The derivation of the evaluation function F (n) is carried out by the priority (α) within each communication condition as shown in the equation 1.
_i (n)) and the priority (β
It is assumed that the sum of the products of _j (n)) and the value of the evaluation function F (n) is large is a mobile node with high priority, that is, high priority.

[0026]

[Equation 1]

When the evaluation functions F (n) are equal,
It is assumed that the mobile node with a long connection time or long stay has a high priority. FIG. 7 shows the evaluation function F (n).
The example of the evaluation value regarding each user information for is shown. In the column 701, items of user information are registered.
This item is the user information shown in the priority among the user information shown in FIG. The column 702 is the priority (β
For convenience of description, _j (n)) is shown by a symbol.
In the column 703, the priority for each communication condition defined in FIG. 6 is input. On the other hand, row 501 has column 7
It is the priority (α _i (n)) within the communication condition stored in each item indicated by 01, and is indicated by a symbol for convenience of explanation. Then, in line 502, the priority shown in five stages within this communication condition is entered.

For example, the evaluation function F (MN) of the user who is using the mobile node MN having the user information as shown in FIG. 8 is obtained as follows. Here, FIG.
Then, for simplification of description, it is assumed that the user information is composed of four communication conditions including a charge system, a band, a reduction frequency, and a data type. First, regarding the charge system, since the mobile node MN contracts for “High-Plan”, the priority within the communication condition, that is, α
_i (MN) is "5", and the priority between one user information, that is, β _j (MN) is "7". Therefore, α _i (MN)
× β _j (MN) is the product “35” of these. Similarly, that of the band is "1", that of the reduction number is "9", and that of the data type is "10". These numerical values are shown in the column of α _i (MN) × β _j (MN) in FIG. Above, α _i (MN) for four user information
Since × β _j (MN) can be obtained, the evaluation function F (MN) for the mobile node MN can be obtained as the sum of these. That is, F (MN) = 3
5 + 1 + 9 + 10 = 55. This evaluation function F (M
The value “55” of N) is the priority which is an index representing a composite priority.

(2) Bandwidth Allocation and QoS Guarantee Method at Handover FIG. 9 is a flowchart showing a QoS guarantee method of the mobile node according to the present invention. Here, in FIG. 1, a case where the user is going to move from the cell 8b to the cell 8c while using the mobile node 10 will be described.

The user having the mobile node 10 is in the cell 8b and is moving while using the mobile node 10. Based on the movement information from the mobile node 10 possessed by the user, the SRNC 4 detects that the mobile node 10 is about to move to the cell where the radio channel is set up by the RNC 6, that is, the cell 8c in the case of FIG. (Step S1). In this case, the movement information from the mobile node 10 possessed by the user is information such as rake reception and diversity.

The SRNC 4 uses the radio network signal RNSAP to the DRNC 5 which sets the radio line of the cell 8c to which the mobile node 10 has moved, by using the radio network signal RNSAP (radio link setup request, Radii
An o_Link_Setup_Request message is transmitted (step S2). The format of the message transmitted from the SRNC 4 to the DRNC 5 in the radio network signal RNSAP has the message format 1001 shown in FIG. Where 101
0 is a normal IP header, which stores information necessary for communication in the network layer. Reference numeral 1011 denotes a user ID of the mobile node 10, which is used to identify the user having the mobile node 10, and may be the user's telephone number, terminal number, or other number. A data type 1012 is used for communication, and types such as voice, data communication, and streaming as shown in FIG. 5 are stored.
1013 is the number of times of reduction, which is the number of times the band has been reduced by the handover of another mobile node described later. 1014 indicates the current band used by the cell 8b of the mobile node 10 and 1015 indicates the mobile node 1
The current connection time in cell 0b of 0 and the stay time in cell 8b are stored in 1016.

Radio_Link_ from SRNC4
The DRNC 5, which has received the Setup_Request message, sends a band allocation information request message to the GGSN1 and SGSN3 in order to acquire the user information 1101 of the mobile node 10 as illustrated in FIG.
(Step S3). This band allocation information request message contains at least the user ID of the user who has the mobile node 10 to be handed over. In this embodiment, for simplification of description, it is assumed that the SGSN3 stores a database equivalent to the HLR2 in which user information such as a charge plan of the illustrated user is stored. It is assumed that the user information illustrated in FIG. 11 such as customer information, priority, contract plan (contents) of the user having the mobile node is managed by. Of course, SGSN3 does not maintain a database inside it,
It is also possible to obtain the necessary data through HLR2.

As shown in FIG. 11, as the main elements constituting the user information 1101 held in the SGSN3, the user ID 1110, the fee system 1111, the current band 1112, the data type 1113, the number of reductions 1114,
Connection time 1115, veto power 1116, stay time 1117
Is mentioned. The user ID 1110 identifies the user who owns the mobile node. The charge system 1111 is the same as the charge system shown in FIG.
The maximum bandwidth limit and the minimum bandwidth to be connected are determined according to the fee system subscribed by the user. Current band 111
2 is the mobile node 10 or 11 used by the user
a to 11e are communication bandwidths currently used. This is updated and held by the RNC 6 (SRNC4, DRNC5) at regular intervals. The data type 1113 has the same content as described in FIG. The number of reductions 1114 is also the same as that already described in FIG. 4, and counts the number of reductions so that the band of the same mobile node is not continuously reduced. The connection time 1115 indicates the communication holding time for the current data type. The veto right 1116 indicates whether or not the veto right of accepting the band reduction is present or not when another mobile node hands over from another cell to the cell to which the mobile node belongs, when there is a request for the band reduction. It is shown. The staying time 1117 indicates the staying time of the mobile node in the current cell.

SGSN3 uses these user information to
The data regarding the mobile node 10 and the data of the users having the mobile nodes 11c to 11e existing in the cell 8c to which the mobile node 10 is about to move are extracted and used as a DRNC as a band allocation information response message.
5, and the DRNC 5 acquires the band allocation information response message (step S4). FIG. 12 shows an example of the format 1201 of the band allocation information response message. The bandwidth allocation information response message 1201 is I
P header part 1210, user information 1211 of a user having the mobile node 10, a user having a mobile node existing in the cell to which the mobile node 10 is about to move, that is, mobile nodes 11c to 11e existing in the cell 8c in this embodiment. The user information 1212 of the user having User information 12
11, 1212 are composed of the elements shown in FIG.

The DRNC 5, which has received the band allocation information response message from the SGSN 3, determines the priority of each mobile node from the user information of all the mobile nodes 11c to 11e belonging to the cell 8c and the user information of the mobile node 10. Then, the bandwidth is reallocated (step S5). Band re-allocation is performed by the band allocating means that the DRNC 5 has internally based on the composite priority calculation method described in (1) above. Where DRNC5
Mobile nodes 11c to 1 belonging to cell 8c managed by
The user information of 1e shall be transmitted to DRNC5 and SGSN3, when each user connects to DRNC5, and shall be hold | maintained there. Information about elements that change with time, such as current connection bandwidth information, is updated at regular intervals using a link update request, a link maintenance request, and the like, and is held by the buffers of DRNC 5 and SGSN 3. . This DRNC5 and SGS
The information periodically held in the N3 buffer is used as the latest information when calculating the evaluation function F (n).

FIG. 13 is a diagram showing a schematic configuration of the band allocating means 1310. The band allocating means 1310 is
A buffer 1301 holding user information of a user having mobile nodes 11c to 11e in wireless communication belonging to a cell 8c managed by the DRNC 5, and a buffer holding user information of a user having a mobile node 10 trying to move to the cell 8c. 1302 and an evaluation function processing unit 1304 that obtains a composite priority of each user
And a buffer 1303 for storing the composite priority of each user obtained by the evaluation function processing unit 1304. The bandwidth allocating means 1310 uses the buffer 1
For each of the users of the mobile nodes 11c to 11e belonging to the cell 8c stored in 301, the evaluation function processing unit 1304 calculates the evaluation function F (n) based on the above Expression 1. Then, each calculated evaluation function F (n) is written and stored in the buffer 1303. The user information of the user having the mobile node 10 acquired in step S4 is stored in the buffer 1
302 is temporarily held, and similarly the evaluation function processing unit 13
After the evaluation function F (MN) is calculated in 04, the value of the evaluation function F (MN) is written in the buffer 1303,
Is stored.

The DRNC 5 uses the band allocating means 1310.
Evaluation function F of the mobile node 10 obtained by
(MN) value and the mobile nodes 11c to 11c in the cell 8c.
11e is compared with the value of the evaluation function F (n), the priority of the mobile node 10 is determined, and it is determined whether the mobile node 10 can hand over from the cell 8b to the cell 8c (step S6). ).

When the mobile node 10 can hand over to the cell 8c (Yes in step S6), that is, the priority (evaluation function) F (MN) lower than the priority (evaluation function) F (MN) of the mobile node 10. ) F (n)
If there is a mobile node having the bandwidth, the mobile node whose bandwidth is to be reduced is determined, and the number of bandwidths to be reduced by that mobile node is also determined (step S7).
As a mobile node for reducing bandwidth, the buffer 130
The smallest value of the evaluation function F (n) stored in 3 is selected. Then, the number of bands to be reduced is uniquely determined so as to be equal to the number of bands used by the mobile node 10 performing the handover in the cell 8b. Here, if the number of bands of the mobile node 10 performing the handover is larger than the number of bands of the mobile node having the smallest value of the evaluation function F (n) (more accurately, the mobile performing the handover). If the number of bands of the node 10 is larger than the number of bands of the current band of the mobile node having the lowest evaluation function F (n) minus the number of guaranteed bands of the mobile node), the band of the mobile node 10 The number of mobile nodes that can secure the number is selected in order from the smallest value of the evaluation function F (n), and the number of bands to be reduced is determined. In this case,
Since the minimum bandwidth corresponding to each fee setting is secured for the users using each mobile node, the communication of the user belonging to the cell 8c is disconnected by the movement of the mobile node 10 to the cell 8c. There is no end. That is, the lowest band according to the charge setting selected by each mobile node is the mobile node 11c-11.
Guaranteed by e.

A mobile node that reduces the bandwidth and a DRNC 5 that determines the number of bandwidths that the mobile node reduces.
Sends a bandwidth reduction request message (modification request, Modificatio) to SGSN3.
n_Request) is transmitted. The SGSN 3 updates the internal user information database according to the received bandwidth reduction request message (step S8). FIG. 14 shows an example of the format of the bandwidth reduction request message. The bandwidth reduction request message 1401 is I
It comprises a P header section 1410, a band securing requesting section 1411 and a band reduction requesting section 1412. Bandwidth securing request unit 14
The band 11 stores the band allocated to the mobile node 10 when the mobile node 10 moves to the cell 8c and necessary user information. The band reduction request unit 1412 stores the band to be reduced, the band after the reduction, and necessary user information for the mobile node whose band is reduced when the mobile node 10 moves to the cell 8c. Here, the number of reductions is stored by adding "1" times to the number of reductions thus far. When there are a plurality of mobile nodes to be reduced, the bandwidth reduction requesting unit 1412 and information about those mobile nodes are repeatedly stored. This bandwidth reduction request message 1401 is SGS
Radio access bearer for N3 (hereinafter Radio)
Access bearer), and the mobile node 10 is updated by updating the user information of the database of SGSN3.
Is officially decided to hand over to cell 8c.

SGSN3 with its internal database updated
Is a bandwidth reduction response message (modification response, Modificatio) including an allocation change message of Radio Access Bearer.
(n_Response) is transmitted to the DRNC 5 and the mobile node belonging to the band reduction target cell 8c. And
By reassigning the Radio Access Bearer, the band for the mobile node 10 to handover from the cell 8b to the cell 8c by changing the radio channel settings in the SRNC4, the node B7b and the mobile nodes 10 and 11b belonging to the cell 8b. Is secured (step S9). In addition, this Radio Ac
The change message of cess Bearer is defined in the existing “3GPPTR23.060-6.12.1”.

FIG. 15 shows the above Radio Acces.
It is a figure which shows an example of the mechanism which reallocates a zone | band by changing s Bearer. Since it is necessary to control the flow according to the number of bandwidth reductions, the mechanism is built into the existing scheduling mechanism. The mechanism for reallocating the band includes a transmission queue 1501 for each mobile node 11c to 11e of the cell 8c, a transmission control unit 1502, a band allocation unit 1504 having the structure of FIG. 13, and a transmission unit 1505. The transmission queue 1501 also has a function 1506 for reporting the current number of bands to the band allocation unit 1504 when packets are periodically transmitted by the transmission unit 1505 to other network terminals. The bandwidth allocating unit 1504 also periodically receives a queue length report 1503 from the transmission queue 1501. Then, the band allocation unit 1504 performs transmission control based on the received queue length report 1503 and the current band report 1506. In addition, the transmission control method is determined based on the change in band allocation, and the transmission queue 1 is transmitted using the transmission control unit 1502.
Control the flow of 501. In this embodiment, the mobile node belonging to the cell 8c whose band has been reduced is controlled so as to reduce the throughput and allocate the band to the mobile node 10 that has handed over.

At step S9, the mobile node 1
0 can be handed over to the cell 8c (step S10). A method proposed in the existing system as a handover method for the mobile node 10 (“3GP
PTR 25.931 "radio link addition can be used. That is, after the DRNC 5 determines that the mobile node 10 can be handed over, DR
NC5 uses the message of the application protocol for Node B (hereinafter referred to as NBAP) to execute DRNC
Wireless connection establishment request (radio link setup request, Radio_
Link_Setup_Request) to enable reception of the uplink at the Node B 7c. After this, the Node B 7c sends NBAP as a response message.
To establish a wireless connection (Radio Link Setup Response, Radio_Link_Setup_R
response) to the DRNC 5. Now that it is possible to receive the uplink, DRNC
5 transmits a wireless connection establishment response (radio link setup response) to SRNC 4 using RNSAP as a response message in step S2.

As described above, since the wireless connection can be established (radio link setup, Radio Link Setup), D can be set between the SRNC 4 and the node B7c.
CH-FP (Dedicated Channel-F)
frame protocol), downlink and uplink are synchronized, and downlink transmission becomes possible (step S11). Radio resource control (RRC) messages are exchanged between the SRNC 4 and the mobile node 10 to establish a radio link (step S
12). Then, the handover of the mobile node 10 ends.

In FIG. 16, in step S6, the mobile node 10 and the mobile node 11c when the mobile node 10 can perform handover from the cell 8b to the cell 8c.
11A to 11e are diagrams illustrating an example of band reallocation between the mobile node 10a and the mobile node 1e, in which FIG. 11A shows user information of each user when the mobile node 10 is in the cell 8b, and FIG.
0 indicates user information of each user when moving to the cell 8c. In FIG. 16A, 1610 indicates user information of the mobile node 10, and as a result of the processing by the evaluation function processing unit 1304, its priority F (MN) is 80, and 1611c to 1611e are assigned to the cell 8c. Shows user information of the mobile nodes 11c to 11e to which the mobile nodes belong,
Their priorities F (n) are 60, 65 and 40, respectively.
Suppose As a result, the mobile node 10 has the highest priority and the mobile node 11e has the lowest priority. 16A, the mobile node 1
Looking at the "current band" of the user information of 0, "32 Kbp
s ”, and the“ current band ”of one mobile node 11e is“ 64 Kbps ”. Therefore, the mobile node 10 can perform the handover from the cell 8b to the cell 8c by reducing the band of the mobile node 11e.

Steps S7 to S12 described above
By the processing of 1, the bandwidth of the mobile node 11e is reduced, the required bandwidth of the mobile node 10 is secured, and the link is established, and then the mobile node 10 moves to the cell 8c. Looking at FIG. 8 (b) after the mobile node 10 has moved to the cell 8 c, the mobile nodes 10, 1
1c, 11d user information 1610 ', 1611c',
1611d ′ has not changed even after the handover of the mobile node 10, whereas the “current band” and “reduction frequency” of the user information 1611e ′ of the mobile node 11e have been changed. That is, the “current band” is reduced to “32 Kbps” and the “reduction frequency” is changed from “0” to “1”. In this way, the mobile node 10 can be handed over using the composite priority, and the QoS of the mobile node can be guaranteed even when the cell moves.

On the other hand, in step S6, the mobile node 1
0 cannot be handed over (step S
No. 6), that is, when the value of the priority F (MN) of the mobile node 10 is lower than the value of any priority F (n) of the mobile nodes 11c to 11e belonging to the cell 8c, the cell 8c. On the other hand, since a sufficient band for the mobile node 10 to move cannot be secured, the mobile node 10 is in a state in which it cannot be handed over to the cell 8c like the existing system.

When the mobile node 10 cannot move to the cell 8c, it is determined whether or not the mobile node 10 can move to another cell (step S21). This judgment is made in cell 8
It is determined whether or not there is another cell that further overlaps with the overlapping portion of b and the cell 8c. If the mobile node 10 can perform handover to a cell other than the cell 8b (Y in step S21)
es), that is, cell 8b and cell 8c
If there is another cell in the overlapping portion of, the process returns to step S2 and the same processing is performed for that cell. However, if there is no cell that can be handed over (No in step S21), that is, if there is no other cell in the overlapping portion of the cells 8b and 8c, the band is secured in the cell of the movement destination. However, the communication is disconnected as in the existing system (step S2).
2).

FIG. 17 is a diagram showing an example in which the mobile node 10 cannot perform handover from the cell 8b to the cell 8c in step S6. In FIG. 17, reference numeral 1710 denotes user information of the mobile node 10, and as a result of the processing by the evaluation function processing unit 1304, its priority F (MN) is 5
0, 1711c to 1711e indicate user information of the mobile nodes 11c to 11e belonging to the cell 8c, and their priority F (n) is 60, respectively.
It is assumed that they are 65 and 70. As a result, the mobile node 1
It can be seen that there are no mobile nodes with priorities F (n) lower than 0, and mobile node 10 has the lowest priority. Therefore, the mobile node 10 cannot hand over to the cell 8c, and transitions to step S21 described above. Also here, if the mobile node 10 cannot be handed over to another cell, the communication of the mobile node 10 is disconnected as it is according to the conventional method. on the other hand,
If it is possible to perform a handover to another cell in step S21, the process returns to step S2, and the same process is performed for that cell.

In the above description, the allocation of the band of the mobile node 10 trying to move from the cell 8b to the cell 8c has been explained, but a user in the cell 8c tries to start a telephone call by radio communication. In the case of allocating the band, the same method can be used.

[0050]

As described above, according to the present invention, the priority of each mobile node is obtained from a plurality of communication conditions prioritized based on a database and a grade value for each communication condition. Since a priority calculation step is provided, a composite priority is calculated from the user information of each node, and even if the cell to be handed over is in a congested state, communication is performed in advance for the user to be handed over. It is possible to secure the destination band. In addition, since there is no change in the band before and after the movement of the cell, the user of the mobile node can continue the communication even after the movement without recognizing the movement. Also, in an environment where soft handover can be performed, there is no communication disconnection time during cell movement such as momentary interruption, so that users who receive data distribution services such as streaming do not feel uncomfortable. .

According to the next invention, since the communication condition includes two or more of the charge system, the band, the number of reductions, and the data type, a finer priority is calculated by combining a plurality of different communication conditions. Therefore, it is possible to eliminate the bias of the nodes for which bandwidth reduction is executed. Further, by reallocating the band according to the priority setting, it is possible to preferentially allocate the band to a user or data type having a high priority.

According to the next invention, the content of the database is updated according to the bandwidth reassigned by the bandwidth allocating step, so that the database has the latest content when calculating the priority. Communication conditions can be provided.

According to the next invention, in the priority calculation step,
Since an evaluation function is used to calculate the sum of the product of the priority of each communication condition and the grade value of each mobile node set for each communication condition as a priority, the evaluation function for each mobile node is used. It is possible to easily derive the priority among the mobile nodes by calculating a composite priority from the user information.

According to the next invention, the radio access network control device obtains the priority based on the user information of the mobile node, and redistributes the band so as to secure the band of the mobile node handing over according to the priority. Since the bandwidth allocating means for performing the above is provided, it is possible to guarantee the bandwidth of the moving destination in advance to the mobile node which performs the handover. In addition, since there is no change in the band before and after the movement of the cell, the user of the mobile node can continue the communication even after the movement without recognizing the movement. Also, in an environment where soft handover can be performed, there is no communication disconnection time during cell movement such as momentary interruption, so that users who receive data distribution services such as streaming do not feel uncomfortable. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a QoS guarantee method for a mobile node according to the present invention.

FIG. 2 is a diagram showing an example of a relationship between a charge system and priority.

FIG. 3 is a diagram showing an example of a relationship between band and priority.

FIG. 4 is a diagram showing an example of the relationship between the number of reductions and priority.

FIG. 5 is a diagram showing an example of a relationship between data type and priority.

FIG. 6 is a diagram showing an example of a priority relationship between user information.

FIG. 7 is a diagram illustrating an example of a method of determining an evaluation function.

FIG. 8 is a diagram showing an example of contents of user information for calculating an evaluation function.

FIG. 9 is a diagram showing a processing flow of a QoS guarantee method for a mobile node according to the present invention.

FIG. 10 is a diagram showing an example of a message format from SRNC to DRNC.

FIG. 11 is a diagram showing an example of user information held in the SGSN.

FIG. 12 is a diagram showing an example of a message format from the SGSN to the DRNC.

FIG. 13 is a block diagram showing an outline of a configuration of a band allocation unit.

FIG. 14 is a diagram showing an example of a message format from DRNC to SGSN.

FIG. 15 is a block diagram showing an outline of a mechanism of band reallocation.

FIG. 16 is a diagram showing an example of band allocation when the mobile node can perform handover from the cell 8b to the cell 8c.

FIG. 17 is a diagram showing an example of a case where a mobile node cannot perform handover from cell 8b to cell 8c.

[Explanation of symbols]

1 gateway node (GGSN), 2 location information
Service information management system (HLR), 3 service node (SGSN), 4 first radio access network controller (SRNC), 5 second radio access network controller (DRNC), 6 radio access network controller (RNC) ), 7a-7c Node B, 8a-8c cells, 9 network, 10
Mobile node, 11a-11e Other mobile nodes.

Claims (5)

[Claims] 1. When a handover mobile node that is about to perform handover is detected, a correspondence relationship between a plurality of prioritized communication conditions and a grade value for each communication condition is determined based on the contract content of each mobile node. Using a database set for each, the priority calculation step of obtaining the priority of each of the handover mobile node and the mobile node communicating in the handover destination cell, based on the calculated priority, When it is detected that a mobile node having a priority lower than that of the handover mobile node exists in the cell of the handover destination, the priority of the mobile node is low, provided that the minimum bandwidth defined in the contract content is secured. By reducing bandwidth from the mobile node in the order of priority A mobile node comprising: a band allocation step of reallocating a band; and a band allocation step of reallocating a band to the handover mobile node and the mobile node according to the band redistribution in the band allocation step. QoS guarantee method. 2. The mobile node QoS guarantee method according to claim 1, wherein the communication condition includes two or more of a charge system, a band, a number of times of reduction, and a data type. 3. The QoS guarantee method for a mobile node according to claim 1, wherein the content of the database is updated according to the band of the mobile node reallocated by the band allocating step. 4. The priority calculation step calculates, as the priority, a sum of a plurality of communication conditions, which is a product of a priority of each communication condition and a grade value of each mobile node set in each communication condition. 4. The QoS guarantee method for a mobile node according to claim 1, wherein the evaluation function is used to calculate the priorities of the handover mobile node and the mobile node, respectively. . 5. A correspondence relationship between one to a plurality of radio access network control devices for controlling mobile nodes in a plurality of cells, a plurality of prioritized communication conditions and a grade value for each communication condition. A database in which user information is set for each mobile node based on the contract content of each mobile node, and a service node for managing the radio access network control device are provided, and the radio access network control device attempts to perform handover. When a handover mobile node that is present is detected, the user information regarding the handover mobile node and the mobile node communicating in the handover destination cell is received from the database via the service node, and based on the received user information. The hand o When the priority of each of the mobile node and the mobile node is obtained and it is detected that there is a mobile node having a priority lower than that of the handover mobile node based on the calculated priority, the contract content is determined. The bandwidth is re-allocated by reducing the bandwidth in the order of priority from the mobile node having a low priority, and the re-allocated bandwidth allocation information is provided to the service. A bandwidth allocating unit for transmitting to the node, the service node updating information stored in the database in accordance with the bandwidth allocating information transmitted from the radio access network control device, and a content stored in the updated database. According to the radio access network controller QoS assurance system of the mobile node, characterized in that it comprises a bandwidth allocation means for allocating a bandwidth to the mobile node and mobile node.