JP2002185500A - Communication system, determining method for alternative route of the system, and recording medium for recording determining program of the alternative route - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a communication system for setting and updating proper alternative routes in the standard network system of a 3rd GPP and for eliminating effectively generations of the congestions, to provide a determining method for the alternative routes, and to provide a recording medium for recording therein the determining program of the alternative routes. SOLUTION: In the communication system, a connection managing node for monitoring traffics on a communication network and for controlling its communication routes has a traffic-information monitoring means and has a means for communicating traffic-informations to the external. Also, each SGSN for relaying informations between each GGSN of an external gateway and each user terminal has a means for monitoring cost-metric informations in a public land mobile network and has a cost-metric-information communicating means for notifying cost-metric-information tables to external nodes. Further, each user terminal has an information-table receiving means for acquiring therefrom the informations of the notified states of the communication network from external nodes and has a communication-route controlling means for deciding optimum communication routes based on the acquired informations and for connecting each user terminal with the optimum communication routes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the use of an IP network (Internet Protocol Network) by mobile communication.
In particular, the third generation mobile communication system GPRS (General
The present invention relates to a communication system for solving the problem of detour routes and congestion in a packet radio service (general-purpose packet radio service), a detour route solution method thereof, and a recording medium on which a detour route solution program is recorded.

[0002]

2. Description of the Related Art General packet radio service (General Pa)
cket Radio Service (GPRS) stands for GSM (global s), a digital cellular system of the European Union standard.
ystem for mobile communication) This is a packet switching service with a network as the backbone.

In addition, general packet radio services (GPR)
The communication system according to S) includes, for example,
There is a prior art disclosed in 2011172.

As a main node constituting a communication network of a general packet radio service, SGSN (Serving GPRS Sup
port Node) and GGSN (Gateway GPRS Support Nod)
There are two types of nodes, e). These SGSN and GGSN are user terminals (communication terminals, Mobile S
tation: MS) and the communication destination relay the communication.

FIG. 9 is a block diagram showing a configuration of a communication system using a conventional general packet radio service (GPRS).

The SGSN 40a is a public land mobile network (Publ
ic Land Mobile Network (PLMN) 100 transfers data with the user terminal (MS) 20a and the GGSN 60. That is, the SGSN 40a is a subordinate node, a radio network controller (Radio Network Controller: R).
In this case, an uplink call from the NC 30 is collected, and a downlink call from the GGSN 60 is distributed to the radio network controller 30. SGSN40a
Is tunneling with GGSN60.
Perform packet transfer according to g).

Here, a public land mobile network (Public Lan)
d Mobile Network (PLMN) 100 is one communication service area under the control of a certain mobile communication carrier.

[0008] The SGSN 40a uses an HLR (Home L).
ocation Register) 50
I always receive a copy of my subscriber information data. Here, the HLR 50 is a database of subscriber information (registered location information, billing information, and the like), and transmits a copy of the data to the SGSN 40a and the like.

The GGSN 60 makes a network connection to an external packet data network. That is, GGSN60
Is a gateway for collecting uplink calls from the subordinate node SGSN 40a and accessing an external IP network or the like. G
GSN 60 may use SGSN4 for downlink calls.
Tunnel up to 0a.

In FIG. 9, the network to which the GGSN 60 accesses is an IP network (Internet Protocol).
Network) 200. Also, the GGSN provided on the side of the IP network 200 is referred to as an access point (AP) 61 in this specification.

[0011]

However, the communication by the conventional general-purpose packet radio service described above has the following problems.

In the specification of the general packet radio service which is a packet switching radio system in the third generation mobile communication technology, a gate function with an IP network (Internet Protocol Network) is integrated in the GGSN. For this reason,
Conventionally, there has been a problem that congestion at a GGSN node is particularly likely to occur.

FIG. 10 is a diagram for explaining switching of a communication path by the conventional general packet radio service (GPRS).

In the public land mobile network 100, SGS
N40a and GGSN60 are provided at a plurality of locations,
Here, the respective nodes are referred to as first, second,.
, N-th,... It is required to prevent the occurrence of congestion and realize appropriate communication by switching the communication path according to the current position of the user terminal 20a of the user and the communication traffic at each of these nodes.

That is, the GGSN that accesses the IP network
Reference numeral 60 denotes an uplink from the user terminal 20a (Uplin).
k) Traffic congestion is likely to occur.

In FIG. 10, first, the user
Communication from the user terminal 20a has started at the position indicated by the dotted line. Therefore, at the start of communication, the user terminal 20a is connected to the first SCSN 40a, then to the first GGSN 60, and to the first access point 61 of the IP network 200.

When a terminal transmits an IP packet, for example, when connecting to the Internet with a mobile phone, an access point name (Access Point Name: APN) must be specified. Based on the access point name,
The connection destination GGSN address is determined in the SGSN, and thus the connection destination GGSN is actually determined in the user terminal (MS).

However, even after the user moves as indicated by the arrow and the SGSN communicating with the user terminal 20a is changed to the (n) -th SGSN 40a, conventionally, the GGSN remains unchanged without being changed. Via the first GGSN 60 at the time of connection.

As described above, when the user terminal 20a repeats a handover and moves greatly, the access point set at the time of the first connection is continuously used until the end of communication, so that a roundabout route is inevitable.
Also, each GGSN does not undertake the same load, and traffic tends to concentrate on a specific GGSN.

For example, in FIG. 10, the route of communication from the user terminal after moving is the same as the first GG at the start of connection.
Not only the SN60 but also the (n) th GGSN 60 close to the (n) SGSN 40a and other Gs with less traffic
Preferably, it can connect to the GSN.

Other conventional techniques for resolving congestion in GGSN include “IMT-2000 Network evolution” by NTT DoCoMo Network Laboratories.
Requirements ”(Technical Report SSE2000-36)
There is. In the prior art of the IEICE Technical Report SSE2000-36, it is proposed to solve the GGSN congestion by configuring a new IP network by integrating a network based on a general packet radio service scheme and an IP network. .

[0022] However, 3GPP (3rd Generation Partn
ership Project) standard network system,
G without the need for a new network system
There is a need to solve the problems of GSN congestion and communication path detour.

A first object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide an appropriate detour route to a node GGSN having a gate function in a general packet radio service which is a third generation mobile communication system. An object of the present invention is to provide a communication system that performs setting and updating and effectively eliminates the occurrence of the congestion, a method for solving the bypass route, and a recording medium that stores a program for solving the bypass route.

A second object of the present invention is to provide a communication system for efficiently eliminating GGSN congestion in a 3GPP standard network system, a bypass route solving method thereof, and a recording medium storing a bypass route solving program. That is.

[0025]

To achieve the above object, a communication system according to the present invention comprises a connection management node for monitoring traffic on a communication network and controlling a communication path in a GPRS communication system. And setting and updating of an appropriate detour route for communication to prevent occurrence of congestion.

In the communication system according to the present invention, the connection management node acquires the status of traffic on the communication network, notifies the status to an external node such as a user terminal, and
SGSN which relays between the GSN and the user terminal, acquires information on cost metric in public land mobile network notify the information to the external node such as a user terminal, the user terminal is notified from an external node communication The information of the state of the network is obtained, the optimum communication path is determined based on the obtained information, and the network is connected to the optimum communication path. As a result, it is possible to effectively prevent the occurrence of congestion in a specific GGSN having a lot of traffic.

[0027] In the communication system according to the present invention, the connection management node may include a traffic information monitoring unit for acquiring a traffic state on the communication network, and a traffic information communication unit for notifying an external node of a traffic information table. It is characterized by having.

According to a third aspect of the present invention, there is provided a communication system according to the present invention, wherein a GGSN which is a gateway for inter-network connection with an external packet data network and an SGSN which relays between user terminals are provided in a public land mobile network. A cost metric information monitoring unit for acquiring metric information and a cost metric information communication unit for notifying an external node of a cost metric information table are provided.

In the communication system of the present invention, the SGSN
The cost metric information monitoring means monitors the state of the cost metric in the public land mobile network, and the cost metric information communication means can notify a cost metric information table indicating the information to an external node. in various nodes, the status information of the cost metric can be easily obtained on the side of each node, it becomes easy to perform processing such as selection of a communication route based on the state of the art cost metric.

According to a fourth aspect of the present invention, in the communication system, the user terminal is an information table receiving means for acquiring information on a state of the communication network notified from an external node, and an optimal information table based on the acquired information. Determine the communication path,
A communication path control unit that connects to the optimum communication path.

According to the communication system of the present invention, the user terminal can acquire the traffic information table notified from the connection management node and the cost metric information table notified from the SGSN by the information table receiving means. The communication path control means in the terminal can determine the optimum communication path based on the information in each of these tables and connect to the optimum communication path.

In the communication system according to a fifth aspect of the present invention, the information table receiving means acquires the traffic information table notified from the connection management node and the cost metric information table notified from the SGSN. The communication path control means is a communication path indicating a good path cost in the cost metric information table, and determines the communication path with the best traffic in the traffic information table as the optimal communication path, By specifying a connection to the optimal communication path to the SGSN, the connection is received.

In the communication system of the present invention, in selecting a communication path, first, a communication path showing a good path cost in the cost metric information table is selected.
In order to select a route with good traffic from among the selected communication routes, this method can select a GGSN 60 with a relatively small traffic within a range where the route cost is not so different from the best route. .

According to a sixth aspect of the present invention, in the communication system according to the present invention, when a handover occurs during communication, the user terminal acquires information on the current state of the communication network and optimizes the information based on the acquired information. Is determined, and the connection is switched to the optimum communication path.

In the communication system of the present invention, when a handover occurs in a user terminal, the latest information on the state of the network is automatically obtained, the optimum communication path is determined, and the connection is switched to the optimum communication path. be able to.

In the communication system according to the present invention, preferably, the SGSN receives the traffic information table notified from the connection management node, and the SGSN indicates a good route cost in the cost metric information table. A route, and a communication route having the best traffic in the traffic information table is determined as an optimal communication route, and a means for connecting the user terminal of the user to the optimal communication route is provided. I do.

In the communication system according to the present invention, the SGSN side can determine the optimum communication path for the user terminal to communicate with and connect it.

In the communication system according to the present invention, an RN for relaying a communication between the SGSN and the user terminal is provided.
C, means for acquiring the traffic information table notified from the connection management node, and the cost metric information table notified from the SGSN;
A communication path indicating a good path cost in the cost metric information table, and a communication path having the best traffic in the traffic information table is determined as an optimum communication path, and the user terminal of the user is determined as the optimum communication path. It is characterized by comprising means for connecting to an optimal communication path.

In the communication system of the present invention, the RNC can determine the optimum communication path for the user terminal to communicate with and connect the terminal.

In a communication system according to a ninth aspect of the present invention, the connection management node determines an optimal communication path for an incoming call to the user terminal of the user, and notifies the incoming call through the optimal communication path. It is characterized by comprising communication path control means.

According to the communication system of the present invention, an optimum communication path for an incoming call to a user terminal is determined by a connection management node.
The user terminal can be called by this optimal communication path.

According to a tenth aspect of the present invention, in the communication system according to the tenth aspect, when an incoming call to a user terminal of a user is generated from outside, the connection management node buffers the data packet and the traffic information table. GGSN with good traffic is selected and connected with reference to the GGSN.
Detect the SGSN in which the user terminal is registered from the HLR via the SN, acquire the cost metric information table of the uplink from the SGSN, and refer to the acquired cost metric information table and the traffic information table. To determine the optimal communication route, connect to the GGSN determined as the optimal communication route, and register the user terminal from the GGSN.
By connecting to the GSN, connecting to the user terminal from the SGSN and transmitting the incoming call, an optimal communication route of the incoming call to the user terminal is determined, and the incoming call is determined by the optimal communication route. The communication path control unit for notifying is provided.

In the communication system according to the present invention, the connection management node communicates with various nodes on the communication network to acquire the latest network information, and optimizes the incoming call to the user terminal based on the acquired network information. Is determined, and the user terminal can be called by using the optimum communication path.

In the communication system according to the eleventh aspect of the present invention, the connection management node buffers the data packet when an external incoming call to the user terminal of the user occurs, and GGSN with good traffic is selected and connected with reference to the GGSN.
The SGSN in which the location of the user terminal is registered is detected from the HLR via the SN, and the SGSN is connected to the SGSN in which the location of the user terminal is registered from the GGSN.
And a communication path control unit for connecting to the user terminal and transmitting the incoming call.

In the communication system according to the present invention, the connection management node more simply communicates with various nodes on the communication network to acquire the latest network information, and based on the acquired information on the network, the connection management node receives the latest network information. The optimum communication path of the call is determined, and the user terminal can receive a call through the optimum communication path.

A communication system according to a twelfth aspect of the present invention is characterized in that the user terminal has a global IP address assignment.

Since the communication system of the present invention has a global IP address assignment in the user terminal, an external node can connect to the user terminal by a method of designating the assigned global IP address.

According to a thirteenth aspect of the present invention, there is provided a communication terminal comprising:
In the communication terminal of the communication system of S, a traffic information table indicating a state of traffic on the communication network transmitted from the connection management node monitoring traffic on the communication network, and a traffic information table of the public land mobile network transmitted from the SGSN. An information table receiving unit that receives each of the cost metric information tables indicating a state of the cost metric; and a communication path control unit that determines an optimal communication path based on the acquired information and connects to the optimal communication path. And setting and updating of an appropriate detour route for communication to prevent occurrence of congestion.

In the communication terminal of the present invention, a notification of the traffic state is received from the connection management node for monitoring the state of the traffic on the communication network, and the public land mobile network is transmitted from the SGSN which relays between the GGSN and the user terminal. , And based on the acquired information, determines an optimal communication route and connects to the optimal communication route. As a result, it is possible to effectively prevent the occurrence of congestion in a specific GGSN having a lot of traffic.

According to a fourteenth aspect of the present invention, in the communication terminal, the communication route control means is a communication route indicating a good route cost in the cost metric information table, and has the best traffic in the traffic information table. The best communication route is determined as the optimum communication route, and a connection to the optimum communication route is designated to the SGSN to receive the connection.

According to a fifteenth aspect of the present invention, when a handover occurs during communication, the communication terminal obtains information on the current communication network state, and determines an optimum communication path based on the obtained information. The connection is switched to the optimal communication path.

A communication terminal according to a sixteenth aspect of the present invention is characterized in that it has a global IP address assignment.

In a preferred embodiment of the present invention, the connection management node provided for monitoring traffic on the communication network and controlling the communication path of the communication network comprises the communication network. A step of notifying a traffic information table to an external node and a step of notifying a traffic information table to an external node, and relaying between a GGSN which is a gateway for inter-network connection with an external packet data network and a user terminal. SGSN to obtain cost metric information in a public land mobile network, and a step of notifying an external node of a cost metric information table, wherein the user terminal notifies the traffic notified from the connection management node. Information table and the SGS
Obtaining the cost metric information table notified from N, and a communication path indicating a good path cost in the cost metric information table, and a communication path having the best traffic in the traffic information table, The method further comprises a step of determining the optimal communication path and a step of designating the SGSN to connect to the optimal communication path, and connecting to the determined optimal communication path.

In the alternative route solving method of the present invention, the connection management node acquires the status of traffic on the communication network, notifies the external node such as a user terminal of the status, and establishes a connection between the GGSN and the user terminal. SG to relay
In the SN, obtain information on the cost metric in the public land mobile network and notify the information to an external node such as a user terminal, and the user terminal obtains information on the state of the communication network notified from the external node, An optimum communication path is determined based on the acquired information, and the communication path is connected to the optimum communication path. This allows a particular GGS with heavy traffic
N can be effectively prevented from occurring.

In a preferred embodiment of the present invention, in the case where a handover is performed during communication, the user terminal acquires information on a current communication network state, and uses the acquired information as a basis. To determine the best communication path for
And a step of switching a connection to the optimum communication path.

According to a nineteenth aspect of the present invention, the connection management node determines an optimal communication route for a call to the user terminal of the user, and determines the incoming call based on the optimal communication route. The method further comprises the step of notifying.

In a twentieth aspect of the present invention, the connection management node buffers the data packet when an external incoming call to the user terminal of the user occurs, A step of selecting and connecting a GGSN having good traffic by referring to the traffic information table; a step of detecting an SGSN in which the user terminal is registered from the HLR via the GGSN; Obtaining the cost metric information table; determining the optimal communication route by referring to the obtained cost metric information table and the traffic information table; and determining the GG determined as the optimal communication route.
Connecting the user terminal from the GGSN to the SGSN in which the location of the user terminal has been registered, and connecting the SGSN to the user terminal to transmit the incoming call; An optimal communication path for an incoming call to is determined, and the incoming call is notified by the optimal communication path.

In a preferred embodiment of the present invention, the connection management node buffers the data packet when an incoming call to the user terminal of the user occurs from outside. A step of selecting and connecting a GGSN having good traffic with reference to the traffic information table; a step of detecting an SGSN in which the user terminal is registered in the HLR via the GGSN; Connecting a terminal to the SGSN whose location has been registered;
Connecting the SN to the user terminal and transmitting the incoming call.

According to a twenty-second aspect of the present invention, a computer-readable recording medium storing a computer-readable detour route solving program stores a GPRS by controlling a computer.
A connection management node provided for monitoring traffic on a communication network and controlling the communication route on a recording medium storing a detour route solving program for solving the detour route of the communication network obtains the status of traffic on the communication network. And a step of notifying the external node of the traffic information table, and an SGS for relaying between the GGSN which is a gateway for inter-network connection with the external packet data network and the user terminal.
N comprising: a step of acquiring cost metric information in a public land mobile network; and a step of notifying an external node of a cost metric information table, wherein the user terminal transmits the traffic information notified from the connection management node. Acquiring the cost metric information table notified from the SGSN; and a communication path indicating a good path cost in the cost metric information table, and having the best traffic in the traffic information table. Determining the best communication path as the optimum communication path; and designating the SGSN to connect to the optimum communication path, and connecting to the determined optimum communication path. And

[0060]

Embodiments of the present invention will be described below in detail with reference to the drawings. Further, in the communication system of the present invention, 3GPP (3rd Generation Partn
ership Project), which is designed to prevent and eliminate congestion and set up an appropriate detour route without deviating from the standard specifications.

FIG. 1 is a block diagram showing a configuration of a communication system according to the first embodiment of the present invention. The communication system of the present invention, as shown in FIG.
Connection management node 10 for centrally managing the traffic state of 0
It is characterized by introducing.

FIG. 2 is a block diagram showing the configuration of the user terminal 20 and the SGSN 40 according to the present embodiment, and FIG.
FIG. 3 is a block diagram illustrating a configuration of a connection management node 10 according to the present embodiment.

Referring to FIG. 2, a user terminal 20 (communication terminal) of the present embodiment includes a communication unit 21 for performing wireless communication with the outside, and an information table receiving unit for acquiring an information table from the SGSN 40 or the connection management node 10. 22, and a communication path control unit 23 that selects an optimum communication path for uplink based on the acquired information table and performs the communication. Further, the user terminal 20 has a global IP address and accepts an external connection by the IP address.

The SGSN 40 of the present embodiment includes a communication unit 41 for controlling communication with the user terminal 20 and other nodes, a cost metric information storage unit 42 for recording a cost metric information table, and a cost metric Cost metric information monitoring unit 43 that manages the information of the cost metric information storage unit 42 and updates the data of the cost metric information storage unit 42 to the latest information as needed, and a cost metric information notification unit that notifies the data of the cost metric information table to the user terminal 20 and the like 44. Note that, here, special functions in the present invention are particularly displayed, and it is assumed that other functions that the normal user terminal 20 and the SGSN 40 should have are also provided.

Referring to FIG. 3, connection management node 10 according to the present embodiment includes communication unit 1 for communicating with another node.
1, a traffic information storage unit 12 that records a traffic information table, a traffic information monitoring unit 13 that monitors the traffic of each GGSN 60, and updates the data in the traffic information storage unit 12 to the latest information as needed, and a user who uses the traffic information table. The system includes a traffic information notification unit 14 for notifying the terminal 20 and a communication path control unit 15 for selecting an optimal communication path for downlink based on various information tables.

[0066]GGSN traffic management  The connection management node 10 manages each Internet service
ISP (Internet Service Provider: ISP)
And manage the communication path of the user. This connection management
The node 10 always manages the traffic of the GGSN 60.
Access in ascending order of traffic at that time.
Access Point Name (APN)
Traffic information table @T that is all tabulated_x｝
Prepare.

Here, the access point name is an IP address that the user terminal 20 must specify when making a call.
The name of the access point 61 to the network, which indicates a character string separated by “.”. FIG. 4 is a diagram illustrating an example of the traffic information table {T _x } according to the present embodiment. Here, the name of each access point 61 is represented by APN
_k (k = 1, 2,...). For example, the first
Name of 1 access point is to show the _{APN 11.} Also, in FIG. 4, the traffic of each GGSN 60 is indicated by the number of octets of the processed packet.

The connection management node 10 broadcasts the traffic information table to all the user terminals 20 at regular intervals. That is, the latest traffic information table is notified from the constant connection management node 10 to the user terminal 20, and the traffic information of each GGSN 60 can be dynamically obtained.

The user terminal 20 designates a new access point 61 on the basis of information from the connection management node 10 as described later.
Even if 1 is an access point 61 with little traffic, it cannot be switched to another access point if it is under the jurisdiction of a different Internet service provider. That is, the access point 61 available from the user terminal 20
Only the connection is switched.

For this reason, for example, the connection management node 10 of the present embodiment may be provided for each Internet service provider to switch the connection of the user. In the case of Internet access using only a mobile phone, the Internet service provider and the mobile communication carrier can be the same company. In this case, the connection management node 10 may be installed for each carrier. Good. Also, of course, one (or one) connection management node 10 can switch the connections of the users of a plurality of Internet service providers.
It is equally possible to manage individually for each Internet service provider.

[0071]Route optimization between SGSN and GGSN  Node SGSN40 that relays a call under GGSN60
Is the uplink of the SGSN-GGSN.
Connections arranged in ascending order of the number of route hops (= cost)
Access point name table (cost meter
Information table) @C_x｝_k(K = 1, 2, ...)
Create

The cost metric information table is an extension of the conventional SGSN routing table, and is constantly updated based on the routing information. In addition, the cost metric information table stores the SGSN 40
And is stored in the SGSN 40. FIG. 5 is a diagram showing an example of the cost metric information table {C _x } _k of the present embodiment. Here, the strometric information table managed by each SGSN 40 is indicated by a subscript, and for example, the cost metric information table of the third SGSN 40 is indicated as {C _x } ₃ .

Here, the process of selecting a communication path of the communication system according to the present embodiment will be described. FIG. 6 is a flowchart illustrating a process of selecting a communication path for a call from user terminal 20 in communication according to the present embodiment.

The moving user terminal 20 can receive the traffic information table {T _x } from the constant connection management node 10 (step 601). Further, at the time of location registration, the SGSN of the registration destination (for example, the (k) th SGSN
40) receives the cost metric information table _{{C x} k} from (step 602).

When the user terminal 20 moves to a different SGSN
40 (for example, the first SG
From SN40 to 2nd SGSN40), inevitably cost
The metrics information table is updated to the new one.
(That is, ｛C_x｝ ₁｛C_x｝₂Updated to
).

Then, based on the traffic information table and the cost metric information table, the user terminal 20
The optimal GGSN 60 is determined (step 603).

As the method of selecting the optimum GGSN 60, for example, the following methods can be used. First, paying attention to the higher-ranked access point names in the cost metric information table, all those whose cost difference from the highest-ranked one is within a predetermined fixed value “D” are extracted. Next, the traffic at each access point is examined by searching the extracted access point name from the traffic information table. Then, the access point having the best current traffic condition among the extracted access points (and the GGSN 60 corresponding to the access point) is determined as the connection destination.

In this method, when the value of the fixed value "D" is set to a large value, the problem of the detour route is not solved, so the fixed value "D" is set to a small and appropriate value.
With this method, it is possible to select a GGSN 60 with a relatively small traffic within a range where the route cost is not so different from the best route.

Here, based on this selection method, FIG.
A procedure for selecting an optimal access point (and a corresponding GGSN) from each table in FIG. 5 will be described.

First, the user terminal 20 extracts the access point name from the received cost metric information table of FIG. Here, the predetermined value of the aforementioned (D = 3
00 (octet)). Then, APN ₁ , APN ₂ , and APN ₃ satisfying the condition within 300 (octet) (= D) from APN ₁ indicating the best path cost are extracted.

Subsequently, when the traffic of each extracted access point is searched from the traffic information table of FIG. 4, it is shown that APN ₂ has the least traffic. As a result, the user terminal 20
Select an access point as a connection destination.

Returning to the description of the flowchart of FIG. 6, when calling, the user terminal 20 first specifies a connection destination Internet service provider by its access point name, and transmits a packet to the SGSN 40 (step 604).

In the SGSN 40, the subscriber profile is collated, and the network ID is added to the end of the access point name character string to obtain the GGSN IP address. Thus, the user terminal 20 can connect to the GGSN 60 corresponding to the access point name specified first (step 605).

The above-described GGSN selection processing is also executed at the time of handover (Handover).
Each time the user moves and a handover occurs, a table search is performed to switch to a new access point.

Next, in order to describe the operation of the present embodiment in more detail, examples in the case of a call from the user terminal 20 and the case of an incoming call will be described.

[0086]In the case of a call from the user terminal 20  Referring to the block diagram of FIG. 1 and the flowchart of FIG.
explain. When the first communication starts, the user
The terminal 20 is at the position indicated by the broken line.

At this time, the user terminal 20 looks at the first
In the control area of the SGSN 40, the power is turned on and the location registration (Attach) is performed with respect to the first SGSN 40. In the first SGSN 40, a cost metric information table in which access point names are arranged in ascending order of cost metrics up to each GGSN 60 is constantly updated and recorded based on routing information.

At the time of location registration, the user terminal 20 stores the cost metric information table in the first SGSN.
40 (step 602), and own MM context
(Or another recording medium). Where MM con
The text (Mobility Management context) is subscriber data that is a specification of a general-purpose packet radio service, and is stored in the user terminal 20 or the SGSN 40 at the time of location registration.

The user terminal 20 has a GGSN 60
A traffic information table in which access point names are arranged in ascending order of the traffic is constantly broadcast from the connection management node 10 and is received (step 601).

Here, first, the user terminal 20 transmits the first S
When a call is initiated in the GSN 40 control area to start communication, first, attention is paid to the access point name ranked higher in the cost metric information table, and the cost difference from the highest rank is determined by a predetermined constant. Value "D"
Extract everything within. Next, the extracted access point name is searched from the traffic information table, and the access point with the best traffic is selected as the connection destination (step 603), and connected to this (steps 604, 605).

That is, in the access point selection method of the present embodiment, the cost metric information is prioritized over the traffic information, and the GGSN 60 is selected so that the relative traffic is reduced within a range where the route cost does not change much. Can be connected.

In the example of FIG. 1, at the time of the first connection, the user terminal 20 selects and connects to the first access point 61, that is, the first GGSN 60 as the access point.

Next, handover processing when the user terminal 20 moves while continuing communication and moves to the position indicated by the solid line (within the (n) th SGSN 40 control area) will be described. The user terminal 20 of the present embodiment performs a table search and switches to a new access point in the same manner as the above-described method every time the user moves to perform a handover.

[0094] The user terminal 20 transmits the Rout, which is a general paging area for packet communication, before moving to the current position.
eing Area (RA) several times, each time a new location registration (Routing Area Updat)
e: routing area update) in the same way as the (n) SGSN 40 described below.

The user terminal 20 is connected to the (n) SGSN 40
When entering the Routing Area in the control area, similar to the above-described location registration processing, at the time of the Routing Area Update,
It receives the cost metric information table unique to the (n) SGSN 40 and overwrites its own MMcontext.

Further, the traffic information table is still broadcast from the connection management node 10 to the user terminal 20, so that the latest traffic information table can be referred to.

The user terminal 20 extracts the upper access point name in the cost metric information table from the traffic information table, searches the traffic information table, and connects to the access point with the best traffic among the extracted access points. Switch. In the example of FIG. 1, the third access point 61, that is, the third GGSN 60 is selected as the access point, and the connection is switched to this.

When the above switching process is executed, FIG.
The new communication route indicated by the solid line can reduce the cost metric much smaller than the communication route in the conventional case where the connection is made to the same access point from the time of calling as shown in FIG. GGSN with less traffic and congestion than other GGSNs in the neighborhood
Can be selected and connected.

By the above procedure, the communication system according to the present embodiment can establish uplink and downlink connections.

[0100]When receiving a call to the user terminal 20  Next, processing when a call is received from outside to the user terminal 20
Will be described. FIGS. 7 and 8 show the user terminal of the present embodiment.
Block diagram for explaining an incoming call to terminal 20 and flow
It is a chart. Also, the user terminal 20 here is
It has a global IP address.

First, a downlink packet destined for the IP address of the user terminal 20 is transmitted to the gate (GGSN6
Immediately before reaching 0), it always passes through the connection management node 10. When the packet reaches the connection management node 10 (step 801), the data packet is temporarily buffered in the connection management node 10.

Then, the connection management node 10 refers to the traffic information table of each GGSN 60 provided therein, selects and connects to the GGSN 60 with less traffic, and accesses the HLR 50 (step 802). In the example of FIG. 7, the third GGSN 60 is selected and connected.

The selected third GGSN 60 is HL
Referring to the subscriber information table of R50, I
Based on the P address (destination address), the SGSN IP address whose location is registered by the user terminal 20 is detected (step 803). In the example of FIG. 7, the location of the user terminal 20 is registered in the second SGSN 40.

In the second SGSN 40, the information from the user terminal 20 (that is, from the second SGSN 40)
Since there is an uplink cost metric information table, the third SGSN 60 transmits the second SGSN 40
To obtain the cost metric information table (step 804). The cost metric information table obtained here is transmitted to the connection management node 10.

In the connection management node 10, based on the acquired cost metric information table and the traffic information table provided by itself, the optimum communication is performed in the same manner as in the communication path selection processing by the user terminal 20 described above. selecting a route (step 805).

As a method of selecting the optimum communication path,
For example, in the same manner as in the method described above, the upper access point name in the cost metric information table is extracted, the traffic of the extracted access point is searched from the traffic information table, and among the extracted access points, It is possible to adopt a method of selecting a device having the best traffic condition as an access destination.

In the present embodiment, the reason that the method of referring to the uplink table instead of the downlink is adopted is that each GGSN 60 creates a downlink cost metric information table between each GGSN and SGSN. In this case, the connection management node 10
This is because the method of retrieving information from 60 is extremely inefficient. Here, by referring to the uplink table, almost the same effect as in the case of referring to the downlink table can be obtained only by referring to one GGSN 60.

In the example of FIG. 7, the GGS of this optimal connection destination is
As N, the second GGSN 60 is selected and connected.
Then, the SGSN obtained in the previous step 803
The second SGSN that registers the user terminal 20 of the user from the second GGSN 60 using the 40 address information.
40 and further to the user terminal 20 of the user (step 806).

However, in this series of cases, the mobile user terminal 20 must also be assigned a global IP address.

The uplink and downlink connections are established by the above procedure.

The handover process after receiving a call to the user terminal 20 is performed by selecting an optimal communication path on the user terminal 20 side as described above when a call is made from the user terminal 20. Switching can be performed.

As described above, the communication system of the present embodiment realizes appropriate setting and updating of a detour route without departing from the standard network system of 3GPP, and effectively eliminates the occurrence of congestion. can do.

Next, another embodiment of the communication system of the present invention will be described.

[0114]Other Implementation of Call Procedure from User Terminal 20
Form  Traffic information table used to determine the connection destination GGSN 60
In the first embodiment, the connection management node
10 and the user terminal 20 receives it.
Although it was a method, it is not necessary to limit to this method. For example,
Each time a call is made from the user terminal 20, the user terminal 20
To the connection management node 10 from the
A form in which an information table is obtained is also possible.

[0115]Another implementation of the procedure for receiving a call to the user terminal 20
Form  As described above, the connection management node 10 establishes a communication phase.
To know the location of the hand user terminal 20, the GGSN 60
Is accessed via the HLR 50. At this time,
The GGSN 60 to access will determine the optimal
Often the same as the GGSN 60 of the communication route
It is considered something. Still further, in the embodiment of FIG.
Between GGSN-HLR and between GGSN-SGSN
Reverse signaling has occurred.

For realizing a high-speed connection,
A mode in which the procedure for transmitting the downlink packet does not include the procedure for optimizing the communication path is also effective. That is, the connection management node 10 connects only to the GGSN 60 selected with reference to only the traffic information table. Here, the SGSN 40 that has registered the location of the user terminal 20 of the user with reference to the HLR 50 is detected. Then, without acquiring the cost metric information table and switching to the optimal GGSN 60, the G
The data packet is transmitted to the user terminal 20 via the GSN 60 and the detected SGSN 40.

In the case of this embodiment, the communication path control unit 15 of the connection management node 10 shown in FIG.
The first GGSN 60 is selected based on the traffic information table (step 802 in FIG. 8), but the second GGSN 60 is selected.
The connection is directly made to the user terminal 20 without selecting the SN 60 (step 805 in FIG. 8), and the downlink packet is transmitted.

[0118]Freely set QoS (quality of service)
Embodiment  The communication route selected by the optimization, even if the congestion is small
Even if a new GGSN is selected, SGSN-GGSN
If a detour route with a large number of hops between was selected
More communication costs, and a proper detour
Not a route.

For this reason, in the communication system of the present invention, as described in the first embodiment, first, the cost metric of the highest access point in the cost metric table {C _x } _k is specified in advance. (“D” = 300 (octet) in the first embodiment)
(In the range up to), the access point is selected, and then the communication route is selected with reference to the traffic state. As a result, it is possible to select a good access point whose cost metric falls within a preset range.

Further, by specifying the value of "D" for specifying the range of the cost metric, the QoS of communication can be set freely.

That is, in the communication system of the present embodiment, the value of “D” is set by the communication carrier based on the contract with the user, and each user can freely set the value. The communication is realized by the QoS. For example, a user who is relatively tolerant of taking a relatively detour route may set "D" to a large value. Conversely, a user who wants to use a short communication path can increase the throughput but reduce the number of hops by setting "D" small.
The GPRS QoS specification states "peak throughput cl
ass ”service.

[0122]RNC30 and SGSN40 for optimal
Embodiment for determining the road  The user terminal 20 receives traffic from the connection management node 10.
Information table @T_xIn order to receive と,
Utilizing wireless communication between user terminals 20
Required. However, the use of wireless communication is
You will need the source.

Therefore, in the first embodiment,
The embodiment in which the process of determining the optimum communication route performed by the user terminal 20 is performed by an RNC, a base station, a router, and an SGSN other than the user terminal 20 also realizes efficient communication. can do.

[0124] proxy In this embodiment, the determination processing of the optimum communication path in the user terminal 20 described above, is a proxy in the RNC and SGSN, etc. (prox
y) It can be realized by using functions.
That is, when the user terminal 20 is powered on and performs location registration, after specifying its own proxy node (proxy node), the proxy node side performs processing of the user terminal 20 such as selection of a connection destination access point. You do it.
Also, in the present embodiment, if the node that determines the optimum communication path is not the SGSN, the SG
The SN sends a cost metric table to the node.

Thus, the communication system of the present embodiment
Then, the traffic information table @T _x｝, RNC or S
It is enough to send to a proxy node such as GSN,
There is no need to notify the user terminal 20.

Further, in each of the above embodiments,
Although both the route selection process for the call originating from the user terminal 20 and the route selection process for the incoming call to the user terminal 20 are performed, an embodiment in which only one of these route selection processes is implemented is also available. It is equally possible.

The communication system of the present invention in each of the above-described embodiments and examples includes the functions of the traffic information monitoring unit 13 and the communication path control unit 15 in the connection management node 10 and the communication path in the user terminal 20. In addition to realizing the functions of the control unit 23 and the like and other functions in hardware, a computer program having each function is
It can be realized by being loaded into the memory of the computer processing device. This computer program
Magnetic disks, semiconductor memories and other recording media 80, 9
0 is stored. Then, the functions described above are realized by being loaded from the recording medium into the computer processing device and controlling the operation of the computer processing device.

Although the present invention has been described with reference to the preferred embodiments and examples, the present invention is not necessarily limited to the above embodiments and examples, and various modifications may be made within the scope of the technical idea. Modifications can be made.

[0129]

As described above, according to the communication system of the present invention, by introducing a new connection management node, 3GPP (3rd Generation Partnership Project)
Various problems at the time of mobile Internet access can be solved without deviating from the standard.

In other words, the conventional problems such as inefficiency of making a roundabout detour to always pass through the same access point even when a terminal during communication moves greatly, and each G
It is possible to solve the problem that the traffic of the GSN cannot be distributed and congestion frequently occurs in a specific GGSN having a lot of traffic.

Also, by adopting this system,
Since the problem of the detour route and the problem of congestion of the incoming and outgoing call packets can be solved and the traffic of each GGSN is managed by an independent connection management node, 3GPP (3rd
Generation Partnership Project) No other standard nodes will be overloaded.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a communication system according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a user terminal and an S according to the first embodiment of the present invention;
FIG. 3 is a block diagram illustrating a configuration of a GSN.

FIG. 3 is a block diagram illustrating a configuration of a connection management node according to the first embodiment of this invention.

FIG. 4 is a diagram illustrating an example of a traffic information table {T _x } according to the first embodiment of this invention.

FIG. 5 is a cost metric according to the first embodiment of the present invention.
Information table C _x｝_kIt is a figure showing an example of.

FIG. 6 is a flowchart illustrating a process of selecting a communication path for a call from a user terminal according to the first embodiment of this invention.

FIG. 7 is a block diagram for explaining an incoming call to a user terminal according to the first embodiment of this invention.

FIG. 8 is a flowchart illustrating a process of selecting a communication path for an incoming call to a user terminal according to the first embodiment of this invention.

FIG. 9 shows a conventional general packet radio service (GPR).
Is a block diagram showing the configuration of a communication system according to S).

FIG. 10 shows a conventional general packet radio service (GPR).
It is a figure for explaining switching of a communication course by S).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Connection management node 11 Communication part 12 Traffic information storage part 13 Traffic information monitoring part 14 Traffic information notification part 15 Communication path control part 20 User terminal 21 Communication part 22 Information table receiving part 23 Communication path control part 30 Radio network controller (Radio) Network Controller: R
NC) 40 Serving GPRS Support Node (SGSN) 41 Communication unit 42 Cost metric information storage unit 43 Cost metric information monitoring unit 44 Cost metric information notification unit 50 HLR (Home Location Register) 60 GGSN (Gateway GPRS Support Node) 61 Access Point (AP) 80, 90 Recording medium 100 Public Land Mobile Network (Public Land Mobile Network)
k: PLMN) 200 IP Network (Internet Protocol Network)

Claims (26)

[Claims] In a GPRS communication system, a connection management node that monitors traffic on a communication network and controls a communication path thereof performs setting and updating of an appropriate detour route for communication to generate congestion. A communication system characterized by preventing communication. 2. The connection management node according to claim 1, further comprising: traffic information monitoring means for acquiring a state of traffic on a communication network; and traffic information communication means for notifying an external node of a traffic information table. 1
A communication system according to claim 1. 3. A cost metric information for acquiring cost metric information in a public land mobile network, wherein a GGSN which is a gateway for inter-network connection with an external packet data network and an SGSN which relays between the user terminal and the GGSN. The communication system according to claim 2, further comprising: a monitoring unit; and a cost metric information communication unit that notifies an external node of the cost metric information table. 4. An information table receiving means for acquiring information on a state of a communication network notified from an external node; and determining an optimal communication path based on the acquired information. 4. The communication system according to claim 3, further comprising communication path control means for connecting to the communication path. 5. The information table receiving means obtains the traffic information table notified from the connection management node and the cost metric information table notified from the SGSN, and the communication path control means obtains the cost A communication path indicating a good path cost in the metric information table and a communication path having the best traffic in the traffic information table are determined as the optimum communication path, and the optimum communication path for the SGSN is determined. The communication system according to claim 4, wherein the connection is received by designating the connection to the route. 6. When a handover occurs during communication, the user terminal acquires information on the current state of the communication network, determines an optimal communication path based on the acquired information, and 6. The connection is switched to the communication path of (4) or (5).
A communication system according to claim 1. 7. The SGSN includes: means for receiving the traffic information table notified from the connection management node; and a communication path indicating a good path cost in the cost metric information table; 7. The communication system according to claim 3, further comprising: means for determining a communication path having the best traffic in the table as an optimum communication path, and connecting the user terminal of the user to the optimum communication path. The communication system according to any one of the above. 8. An RNC relaying communication between the SGSN and the user terminal, wherein the traffic information table notified from the connection management node and the cost metric information table notified from the SGSN are acquired. Means, a communication path indicating a good path cost in the cost metric information table, and a communication path having the best traffic in the traffic information table is determined as an optimum communication path, and the user of the user is determined. The communication system according to any one of claims 3 to 7, further comprising means for connecting a terminal to the optimum communication path. 9. The connection management node further includes a communication path control unit that determines an optimal communication path for an incoming call to a user terminal of a user and notifies the incoming call based on the optimal communication path. The communication system according to any one of claims 1 to 8, wherein 10. The connection management node, when an external incoming call to a user terminal of a user occurs, buffers the data packet, and refers to the traffic information table to provide a GGSN with good traffic. To connect, and to detect the SGSN in which the user terminal is registered from the HLR via the GGSN, obtain the uplink cost metric information table from the SGSN, and obtain the obtained cost metric information table Determining the optimal communication route with reference to the traffic information table, connecting to the GGSN determined as the optimal communication route, connecting from the GGSN to the SGSN in which the location of the user terminal has been registered, By connecting to the user terminal from above and transmitting the incoming call, 9. A communication path control means for judging an optimum communication path for an incoming call to the terminal and notifying the incoming call by the optimum communication path.
The communication system according to any one of the above. 11. The connection management node, when an external incoming call to a user terminal of a user occurs, buffers the data packet, and refers to the traffic information table to provide a GGSN having good traffic. Select and connect, and detect the SGSN in which the user terminal has been registered from the HLR via the GGSN, connect to the SGSN in which the user terminal has been registered from the GGSN, and connect the user terminal from the SGSN The communication system according to any one of claims 3 to 8, further comprising a communication path control unit that connects to a communication path and transmits the incoming call. 12. The communication system according to claim 1, wherein the user terminal has a global IP address assignment. 13. A communication terminal of a GPRS communication system, comprising: a traffic information table indicating a state of traffic on a communication network, transmitted from a connection management node monitoring traffic on the communication network; Information table receiving means for receiving each of the cost metric information tables indicating the state of the cost metric of the public land mobile network; and a communication for judging an optimal communication route based on the acquired information and connecting to the optimal communication route. A communication terminal comprising a route control unit, which sets and updates an appropriate detour route for communication to prevent occurrence of congestion. 14. The communication route control means according to claim 1, wherein said cost metric information table is a communication route indicating a good route cost, and said traffic information table is a communication route having the best traffic, and said optimum communication The communication terminal according to claim 13, wherein the communication terminal is determined as a route, and receives the connection by designating a connection to the optimal communication route to the SGSN. 15. When a handover occurs during communication, information on a current communication network state is obtained, an optimum communication path is determined based on the obtained information, and connection to the optimum communication path is performed. The communication terminal according to claim 13, wherein the communication terminal is switched. 16. The communication terminal according to claim 13, further comprising a global IP address assignment. 17. A method for resolving a bypass route of GPRS, wherein a connection management node provided for monitoring traffic on a communication network and controlling a communication path thereof acquires a status of traffic on the communication network. A step of notifying an external node of a traffic information table, wherein a GGSN that is a gateway for inter-network connection with an external packet data network and an SGSN that relays between user terminals are provided in a public land mobile network. Acquiring a metric information; and notifying an external node of a cost metric information table, wherein the user terminal is configured to notify the traffic information table notified from the connection management node and the SGSN notified from the SGSN. the cost metric information table Obtaining, and determining, as the optimal communication path, a communication path that indicates a good path cost in the cost metric information table and has the best traffic in the traffic information table. A method of resolving a detour route, comprising the step of designating the SGSN to connect to the optimal communication path, and connecting to the determined optimal communication path. 18. When a handover occurs during communication, the user terminal acquires information on the current state of the communication network, determines an optimal communication path based on the acquired information, and 18. The method according to claim 17, further comprising the step of switching the connection to the communication path of (c). 19. The method according to claim 19, wherein the connection management node includes a step of determining an optimal communication path for an incoming call to the user terminal of the user, and notifying the incoming call through the optimal communication path. Claim 17 or Claim 1
8. The detour route solving method according to 8. 20. The connection management node, when an incoming call to a user terminal of a user is generated from outside, buffering the data packet, and referring to the traffic information table to improve the traffic. Selecting an appropriate GGSN for connection, detecting the SGSN in which the user terminal is registered from the HLR via the GGSN, and acquiring the cost metric information table of the uplink from the SGSN. A step of determining an optimal communication path by referring to the acquired cost metric information table and the traffic information table; a step of connecting to the GGSN determined as the optimal communication path; Step for connecting to the SGSN whose location has been registered And transmitting the incoming call by connecting to the user terminal from the SGSN, determining an optimal communication route of the incoming call to the user terminal, and notifying the incoming call by the optimal communication route. The detour route solving method according to claim 17 or claim 18, wherein: 21. The connection management node, when an external incoming call to a user terminal of a user occurs, buffering the data packet, and referring to the traffic information table to improve the traffic. Selecting the appropriate GGSN and connecting to it; detecting the SGSN in which the user terminal has been registered from the HLR via the GGSN; connecting from the GGSN to the SGSN in which the user terminal has been registered. The method according to claim 17 or 18, further comprising: connecting the SGSN to the user terminal and transmitting the incoming call. 22. By controlling a computer, G
A connection management node provided for monitoring traffic on a communication network and controlling a communication route on a recording medium storing a detour route solving program for resolving a detour route of a PRS, wherein a state of the traffic on the communication network is determined. Acquiring a traffic information table to an external node, and a GGSN that is a gateway for inter-network connection with an external packet data network and an SGSN that relays between the user terminal and the public land. A step of acquiring cost metric information in a mobile network, and a step of notifying an external node of a cost metric information table, wherein the user terminal transmits the traffic information table notified from the connection management node; and the SGSN. Said co notified from Acquiring the communication information table, and the communication path showing the good path cost in the cost metric information table, and the communication path having the best traffic 0 in the traffic information table, Determining a connection to the optimal communication route to the SGSN, and connecting to the determined optimal communication route. A recording medium on which a program is recorded. 23. When a handover occurs during communication, the user terminal acquires information on the current state of the communication network, determines an optimal communication path based on the acquired information, and 23. The recording medium according to claim 22, further comprising a step of switching a connection to a communication route of the computer. 24. The connection management node comprising a step of determining an optimal communication path for an incoming call to a user terminal of a user, and notifying the incoming call by the optimal communication path. A recording medium storing a computer-readable detour route solving program according to claim 22 or 23. 25. The connection management node, when an incoming call to a user terminal of a user is made from outside, buffering the data packet, and referring to the traffic information table to improve the traffic. Selecting an appropriate GGSN for connection, detecting the SGSN in which the user terminal is registered from the HLR via the GGSN, and acquiring the cost metric information table of the uplink from the SGSN. A step of determining an optimal communication path by referring to the acquired cost metric information table and the traffic information table; a step of connecting to the GGSN determined as the optimal communication path; Step for connecting to the SGSN whose location has been registered And transmitting the incoming call by connecting to the user terminal from the SGSN, determining an optimal communication route of the incoming call to the user terminal, and notifying the incoming call by the optimal communication route. 24. A recording medium recording a computer-readable detour route solving program according to claim 22 or claim 23. 26. The connection management node, when an incoming call to a user terminal of a user is generated from outside, buffering the data packet, and referring to the traffic information table to improve the traffic. a step of selectively connecting a GGSN, step of connecting from the HLR via the GGSN detecting the SGSN to which the user terminal is a location registration from the GGSN, the SGSN that a location registration of the user terminal 24. The computer-readable alternative route solving program according to claim 22 or 23, further comprising a step of connecting the SGSN to the user terminal and transmitting the incoming call. recoding media.