JP6133719B2 - COMMUNICATION SYSTEM, RELAY DEVICE, CONTROL INFORMATION RELAY PROGRAM, AND COMMUNICATION METHOD - Google Patents

Description

  The present invention relates to a technique for controlling registration of a communication terminal to a service control network.

In order to provide multimedia communication services using IP (Internet Protocol) technology, a standard called IMS (IP Multimedia Subsystem) is defined as an international standard in the 3rd Generation Partnership Project (3GPP). The contents of this standard are described in Non-Patent Document 1, for example.
An IMS communication system network (hereinafter referred to as an IMS network) includes a session control function CSCF (Call Session Control Function), an application service control function AS (Application Server), and a user information storage function HSS (Home Subscriber Server).

The CSCF is divided into three functional elements: P-CSCF (Proxy-CSCF), S-CSCF (Serving-CSCF), and I-CSCF (Interogating-CSCF). Hereinafter, the P-CSCF, the I-CSCF, and the S-CSCF may be referred to as CSCF when they are not distinguished from each other.
The P-CSCF is arranged at a connection point between the IMS network and an access network that performs transmission control of information (IP packet) between the IMS network and the communication terminal. And it connects with PDN-GW (Packet Data Network Gateway) arrange | positioned in an access network, and relays the SIP signal (signal containing a SIP message) between S-CSCF and I-CSCF, and a communication terminal.

  Here, the access network is a network that performs transmission control of IP packets from a wireless access system to a PDN-GW that is a connection point with an external PDN (Packet Data Network) including an IMS network. Hereinafter, this access network is referred to as an EPC (Evolved Packet Core) network.

The S-CSCF performs session control and authentication using user information obtained from an HSS (Home Subscriber Server).
The I-CSCF selects the S-CSCF according to the user information of the HSS during registration with the IMS network and session control.

  The AS performs common basic control or general control of each application service in cooperation with the communication terminal.

  The HSS is a database that handles user information of communication terminals that access the IMS network. The user information includes, for example, a private user identifier, a public user identifier, an address of an S-CSCF that performs session control, contract service information, and the like. The contract service information includes information indicating whether the contract user is a priority user.

A communication terminal corresponding to the IMS standard performs session control and service control in cooperation with the IMS network. Therefore, it is necessary to establish a path for transmitting the SIP signal to the S-CSCF via the P-CSCF. Thus, setting the SIP signal transmission path for the IMS network is referred to as registering the communication terminal with the IMS network.
For example, when a communication terminal is a LTE (Long Term Evolution) compatible mobile communication terminal, the communication terminal first connects to an EPC network that accommodates a radio access system in which the communication terminal is located, and then transmits an IP packet. (SIP signal) transmission path is set. This process is a process for registering (location registration) the communication terminal in the EPC network.

Next, the communication terminal transmits a REGISTER message, which is a SIP registration signal including the IP address, private user identifier, public user identifier, and the like of the communication terminal, to the P-CSCF via the EPC network.
When receiving the REGISTER message, the P-CSCF selects an arbitrary I-CSCF and relays the REGISTER message to the selected I-CSCF. The I-CSCF relays the REGISTER message to the S-CSCF allocated in advance to the communication terminal or the S-CSCF suitable for the communication terminal.

  The S-CSCF sets the address of the S-CSCF itself as user information of the communication terminal in the HSS, and derives the authentication vector of the communication terminal from the response signal at that time. Subsequently, the S-CSCF performs user authentication of the communication terminal using this authentication vector. When the user authentication of the communication terminal is successful, the S-CSCF associates and holds the public user identifier, the communication terminal IP address, and the P-CSCF address. Then, this P-CSCF is set as a signal transmission path (S-CSCF → P-CSCF direction) when session control is performed after registration is completed.

Subsequently, the S-CSCF notifies the HSS that the S-CSCF has been assigned for the public user identifier, and extracts the user information from the HSS by a response signal. The S-CSCF holds this user information, and notifies the communication terminal that the registration is completed with a 200 OK message including the public user identifier via the P-CSCF. The communication terminal performs subsequent session control using this public user identifier.
When the P-CSCF receives the 200 OK message, the P-CSCF holds the address of the S-CSCF, and this S-CSCF is used as a signal transmission path (P-CSCF → S-CSCF direction) for session control. Set.

In this way, the communication terminal is registered in the IMS network.
Conventionally, for example, a technique disclosed in Patent Document 1 is a technique for preferentially processing a call from a communication terminal of a priority user such as a VIP user. In such a technique, when congestion occurs in the IP telephone network, a call transmitted from the VoIP terminal of the priority user is relayed in preference to a call transmitted from the VoIP terminal of the general user.

JP 2008-5257 A

3GPP TS 23.228 V12.0.0 (2013-03) 3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; IP Multimedia Subsystem (IMS); Stage 2 (Release 12)

  In the above prior art, for example, as shown in FIG. 10, when the P-CSCF is congested, a UE (User Equipment) which is a communication terminal of a priority user that has already been registered in the IMS network. ) Assume that a SIP INVITE message is transmitted from B to the P-CSCF. In this case, when receiving the INVITE message, the P-CSCF can identify that the user of the UEB is a priority user based on the user information acquired and held from the HSS via the S-CSCF during the registration process. . Therefore, the INVITE message is preferentially relayed to the S-CSCF without being discarded.

On the other hand, in an environment where the P-CSCF is congested, it is assumed that UEA, which is a communication terminal of the priority user, is turned on from the power-off state and performs initial registration (Initial Registration) in the service control network.
In this case, in the above prior art, when the P-CSCF receives the REGISTER message from the UEA, the received REGISTER message is discarded without being relayed, as shown in FIG. There is a case. In this case, a SIP error response message is returned to UEA, and the registration process is not performed.

  That is, since the P-CSCF does not hold the user information of the UEA at the time of receiving the REGISTER message at the time of initial registration, the user of the UEA is the priority user even if the REGISTER message transmitted from the UEA is received. I can't identify that. Therefore, the P-CSCF may discard the REGISTER message transmitted from UEA in the same manner as that from the communication terminal of a general user (a user who is not a priority user).

  Further, in the P-CSCF, after the initial registration with the IMS network, based on the terminal identification information included in the received SIP message, the user information held at the first registration is accessed, and the received SIP message is the UE of the priority user. It is determined whether or not it has been transmitted from. That is, the received SIP signal data (frame data including the SIP message) does not include information for determining whether or not the user is a priority user. Therefore, the P-CSCF cannot determine whether or not the user is a priority user from only the received SIP signal.

Even if information indicating that the user is a priority user is added to the SIP signal transmitted in UEA, and the P-CSCF can determine whether or not the user is a priority user from the received SIP signal, the information is Since there is a possibility that the user will misrepresent at the stage of granting, it is not reliable information.
The present invention has been made to solve such a problem, and controls processing according to control information transmitted from a communication terminal of a priority user with priority, and reduces the processing load. It is an object of the present invention to provide a suitable communication system, relay device, control information relay program, and communication method.

[Form 1]
In order to solve the above-mentioned problem, a communication system of form 1 according to the present invention is arranged in an access network, and the service control is transmitted and received between a communication terminal and a service control network via the access network. Based on a relay device that relays control information for causing the network to control predetermined processing requested by the communication terminal, and the control information that is arranged in the service control network and relayed via the relay device A communication device including a control device that controls the predetermined processing, wherein the relay device is information indicating whether or not a user of the communication terminal held in advance in the user information holding device is a priority user. Based on certain priority user setting information, the user of the communication terminal is the priority user for the control information from the communication terminal. Comprising an identification information addition unit for imparting identification information for identifying whether there.

Furthermore, the control device determines whether or not the user of the communication terminal that is the transmission source of the control information is a priority user based on the identification information given to the control information from the relay device. The predetermined processing according to the control information from the communication terminal of the user who is determined to be a priority user based on the determination result of the determination unit, from the communication terminal of the user who has not determined to be the priority user A control unit that performs control with priority over the predetermined processing according to the control information.
With such a configuration, when the relay device receives control information from the communication terminal, the identification information adding unit performs the control information on the control information based on the priority user setting information held in advance in the user information holding device. The identification information for identifying whether or not the user of the communication terminal as the transmission source is the priority user can be given.

In addition, when the control device receives the control information to which the identification information is added, the determination unit, based on the identification information given to the received control information, determines that the user of the communication terminal that has transmitted the control information is a priority user. It is possible to determine whether or not there is.
Further, the control device performs a predetermined process according to the control information from the communication terminal of the priority user based on the determination result, and performs a predetermined process according to the control information from the communication terminal of the user who is not the priority user. It is possible to control with priority over processing.

  For example, it is assumed that the process of first registering a communication terminal in a service control network in which a control device such as a P-CSCF does not hold user information before registration of the communication terminal, such as an IMS communication system network, is controlled. At this time, since the identification information can be given in the access network with such a configuration, the control device identifies whether or not the user of the communication terminal that is the transmission source of the control information is a priority user from this identification information. be able to. Therefore, it is possible to obtain an effect that the control apparatus can preferentially control the registration process of the priority user communication terminal even in an environment where the control apparatus is congested.

Further, since the identification information is given to the relay device arranged in the access network, it is possible to prevent the preferential user from being misrepresented by an unauthorized user. Thereby, the effect that priority control can be implemented based on highly reliable identification information is acquired.
In addition, in the service control network, it is possible to identify whether or not the user of the communication terminal that is the transmission source of the control information is the priority user from the identification information given to the control information. Thereby, compared with the structure which accesses and identifies the conventional user information, the effect that it can identify whether it is a priority user with a low-load process is acquired.

  Here, for example, when the communication terminal has a telephone function, the predetermined process is a session establishment process at the time of utterance, a session end process at the end of the call, a text message transmission process, and a service for the communication terminal. This includes registration processing that is registered in the control network. The registration process is a process for setting a signal transmission path for control information from a control apparatus arranged at a connection point with an access network in a service control network to another control apparatus that is a relay destination of control information. That's it. Hereinafter, the same applies to the relay device of mode 2, the control information relay program of mode 5, and the communication method of mode 6.

[Form 2]
In order to achieve the above object, the relay apparatus according to aspect 2 of the present invention is arranged in an access network, and is transmitted and received between the communication terminal and the service control network via the access network. A relay device that relays control information for causing the service control network to execute a predetermined process provided by the service control network, and a user of the communication terminal previously held in a user information holding device is a priority user Identification giving identification information for identifying whether or not the user of the communication terminal is a priority user to the control information from the communication terminal based on the priority user setting information that is information indicating whether or not An information providing unit is provided.

With such a configuration, when the relay device receives control information from the communication terminal, the identification information adding unit performs the control on the control information based on the priority user setting information held in advance in the user information holding device. Then, identification information for identifying whether or not the user of the communication terminal as the transmission source is a priority user is given.
Thereby, the effect | action and effect similar to the said form 1 can be acquired.

[Form 3]
Further, the relay device of aspect 3 performs the registration process of the communication terminal to the access network based on the user information including the priority user setting information held in the user information holding device, in contrast to the configuration of the above aspect 2. The identification information adding unit is configured to control the control information from the communication terminal based on the priority user setting information included in the user information acquired during the registration process to the access network. The identification information is given.
As a result, the user information acquired at the time of registration in the access network can be reused and identification information can be added, thereby eliminating the need to re-acquire priority user setting information from the user information holding device. can get.

Here, registration of the communication terminal to the access network means setting a signal transmission path for transmitting control information from the communication terminal to the control device arranged at the connection point of the service control network via the access network. Say. When the communication terminal is a mobile communication terminal, a signal transmission path is set from the wireless access system in which the mobile communication terminal is located to a control device arranged at the connection point of the service control network. Become.
Such registration processing includes, for example, authentication, secrecy, integrity processing, location registration processing, route setting processing, and the like.

[Form 4]
Further, in the relay device of aspect 4, in contrast to the structure of aspect 3, the access network is a network that performs transmission control of IP packets, the service control network is a network of an IMS communication system, and the control The information is a SIP message, and the identification information adding unit adds the identification information to a protocol header of a preset communication protocol among a plurality of layered communication protocols used for relaying the SIP message.

With this configuration, the identification information adding unit can add identification information to a protocol header of a preset communication protocol among a plurality of layered communication protocols used for relaying SIP messages. is there.
As a result, identification information can be given using the priority setting field, the extension field, the spare field, etc. in the protocol header of the existing communication protocol. Therefore, the effect that the improvement of the software at the time of mounting etc. can be suppressed to the minimum is acquired.

[Form 5]
On the other hand, in order to achieve the above object, the control information relay program according to the fifth aspect of the present invention is arranged in the access network, and is transmitted and received between the communication terminal and the service control network via the access network. A control information relay program that is executed in a computer provided in a relay device that relays control information for causing the service control network to control predetermined processing requested by the communication terminal; Whether or not the user of the communication terminal is a priority user with respect to the control information from the communication terminal based on priority user setting information that is information indicating whether or not the user of the communication terminal is a priority user The computer includes a process comprising an identification information providing step for providing identification information for identifying Make.
With such a configuration, when the program is read by the computer and the computer executes processing according to the read program, the same operation and effect as those of the relay apparatus according to mode 2 can be obtained.

[Form 6]
In order to achieve the above object, the communication method of aspect 6 according to the present invention is arranged in an access network and is transmitted and received between the communication terminal and the service control network via the access network. A relay device that relays control information for causing the service control network to control predetermined processing requested by the communication terminal; and the control that is disposed in the service control network and relayed via the relay device A communication method using a mobile communication system including a control device that controls registration processing for registering the mobile communication terminal in the service control network based on information, wherein the relay device is held in advance in a user information holding device. Based on the priority user setting information for setting whether the user of the communication terminal is a priority user, An identification information providing step for adding identification information for identifying whether or not the user of the communication terminal is a priority user to the control information from the communication terminal; and Based on the identification information given to the control information, a determination step for determining whether or not the user of the communication terminal that is the transmission source of the control information is a priority user, and the control device determines whether or not the determination step Based on the result, the predetermined processing according to the control information from the communication terminal of the user determined to be a priority user is performed according to the control information from the communication terminal of the user determined to be not a priority user. A registration process control step for controlling the process with priority over the process.
Thereby, the same operation and effect as those of the communication system of mode 1 can be obtained.

1 is a block diagram illustrating an example of a schematic configuration of a communication system 1. FIG. It is a block diagram which shows the function structural example of EPC-GW of 1st Embodiment. It is a block diagram which shows an example of a function structure of CSCF of 1st Embodiment. It is a flowchart which shows an example of the process sequence of an identification information provision process. (A) is a figure which shows an example of the frame data transmitted / received between S-GW-PDN-GW, (b) shows an example of the frame data transmitted / received between PDN-GW-P-CSCF. (C) is a figure which shows an example which provides identification information to a MAC header, (d) is a figure which shows an example which assigns identification information using the DS field of an IP header. It is a flowchart which shows an example of the process sequence of the identification information provision process of 1st Embodiment. It is a flowchart which shows an example of the process sequence of an initial registration control process. It is a sequence diagram which shows operation | movement after UE of a priority user turns a power supply OFF-> ON until an initial registration process is completed. It is a flowchart which shows an example of the process sequence of the identification information provision process of 2nd Embodiment. It is a sequence diagram which shows the operation example at the time of the conventional initial registration in the environment where P-CSCF is congested.

(First embodiment)
Hereinafter, a first embodiment of a communication system, a relay device, a control information relay program, and a communication method according to the present invention will be described with reference to the drawings.
(1) Configuration (1-1) Configuration Example of Communication System 1 First, the configuration of the communication system 1 according to the present invention will be described with reference to FIG. FIG. 1 is a block diagram illustrating an example of a schematic configuration of the communication system 1.
In the present embodiment, the communication system 1 includes a UE, a radio access system, a 3G (3rd Generation) core network, an EPC network, and an IMS network, as shown in FIG.

In this embodiment, the UE is a mobile communication terminal compatible with IMS and EPC networks, such as a 3G compatible mobile communication terminal, a mobile communication terminal compatible with both 3G and LTE, and an LTE compatible mobile communication terminal.
The radio access network includes a NodeB and an RNC (Radio Network Controller) that constitute a 3G radio access system, and an eNodeB that constitutes an LTE radio access system. Note that the present invention is not limited to this configuration, and a non-cellular wireless access system such as a WiMAX (registered trademark) access system or a WLAN (Wireless LAN) access system may be included.

NodeB (hereinafter abbreviated as NB) is a node that constitutes a 3G radio access system, and is a radio base station that transmits and receives radio signals to and from a 3G-compatible UE.
The RNC is a radio control apparatus that accommodates a plurality of NBs and performs mobility management such as location registration and simultaneous calling within the 3G radio access system.
An eNodeB (hereinafter may be abbreviated as eNB) is a node that constitutes an LTE radio access system, and is a radio base station that transmits and receives radio signals to and from an LTE-compatible UE. The eNB also plays a role of a radio control apparatus that transfers a control signal from the UE to an MME (Mobility Management Entity) and transfers an IP packet from the UE to an S-GW (Serving Gateway).

The 3G core network includes an SGSN (Serving GPRS Support Node) and a GGSN (Gateway GPRS Support Node).
The SGSN is a packet-switched domain node that accommodates 3G-compatible UEs and 3G radio access systems. The SGSN is connected to the MME and S-GW that are arranged in the EPC core network. The SGSN is connected to the HSS shared by the EPC core network and the IMS network.

The GGSN is a packet switching domain node serving as a connection point with other packet networks other than the EPC core network.
Details of the 3G wireless access network and the 3G core network are described in detail in “3GPP TS 23.002 Network architecture (http://www.3gpp.org/ftp/Specs/html-info/23002.htm)”. .

The EPC core network includes an MME, an S-GW, a PDN-GW, and a PCRF (Policy and Charging Rules Function).
The MME has an interface with an LTE-compatible UE existing in the radio zone of the LTE radio access system, and performs UE mobility management, UE authentication, and IP transmission path setting control with the UE. The MME performs UE mobility management and authentication in cooperation with the HSS. Further, the MME performs setting of the transmission path of the IP packet transmitted / received by the UE for the eNodeB and the S-GW.

The S-GW performs IP packet transmission control based on an MME command. Specifically, the S-GW sets an IP packet transmission path in a section from eNodeB to S-GW to PDN-GW when the UE is in the radio zone of the LTE radio access system. Moreover, S-GW sets up the transmission path | route of an IP packet in the area of SGSN-S-GW-PDN-GW, when UE exists in the radio zone of 3G radio | wireless access system.
When determining that the SIP message from the UE has been received, the S-GW relays the SIP message to the PDN-GW.

In addition, when the S-GW of the present embodiment receives an IP packet including a SIP message such as a REGISTER message at the time of initial registration from the UE, the S-GW is based on user information acquired and held at the time of registration in the EPC network. Then, identification information for identifying whether or not the user of the UE is a priority user is added to the frame data when the IP packet is relayed to the PDN-GW.
Here, the priority user is, for example, a user certified as a user who performs priority processing by a communication carrier such as a VIP user.

Further, the REGISTER message at the time of initial registration is a message transmitted when the UE power is turned on from OFF, for example, and is a SIP request message for registering the UE in the IMS network.
The PDN-GW is a connection point with a PDN such as an IMS network or the Internet. All IP packets from the PDN to the UE reach the PDN-GW.

When the PDN-GW receives the frame data including the SIP message from the S-GW, the PDN-GW extracts the identification information given to the frame data. Then, based on the extracted identification information, the PDN-GW identifies whether the user of the UE is a priority user for the frame data when relaying the SIP message to the P-CSCF. Give information.
Hereinafter, S-GW and PDN-GW may be referred to as EPC-GW when they are not distinguished from each other.

The PCRF determines an IP packet transmission policy such as QoS (Quality of Service) and a charging method for performing transmission quality control of IP packets of S-GW and PDN-GW.
The PCRF determines policy information (QoS priority class information and gate information), billing information, and the like to be applied to the user's packet transmission as rules according to the user's contract information and the type of application started by the user. Then, the determined rule including the policy information and the billing information is transmitted to the S-GW and the PDN-GW together with information specifying the IP packet to which the rule is applied.

In addition to the conventional functions, the P-CSCF of the present embodiment receives frame data including a SIP message from the PDN-GW, and based on the identification information given to the received frame data, It is determined whether the user of UE is a priority user. When the P-CSCF determines that the user of the UE is a priority user, the P-CSCF preferentially controls the process according to the SIP message over the UE of a user who is not a priority user (hereinafter referred to as a general user).
Specifically, the P-CSCF transmits the SIP message from the priority user's UE to the I-CSCF without being discarded even when the P-CSCF is in a congested state. On the other hand, the P-CSCF discards the SIP message from the general user's UE in accordance with a preset congestion rule.

In addition, the P-CSCF of the present embodiment, for the frame data including the SIP message to be transmitted to the I-CSCF, based on the identification information given to the received frame data, the UE that is the transmission source of the SIP message Information that can identify whether the user is a priority user (hereinafter referred to as priority information) is assigned.
Specifically, for example, the P-CSCF of this embodiment gives priority information using the value of a CPC (Calling Party's Category) parameter included in the “from” header of the SIP message.

When the I-CSCF of the present embodiment receives frame data including a SIP message transmitted from the P-CSCF, in addition to the conventional functions, the priority information given to the SIP message included in the received frame data Based on the above, it is determined whether the user of the UE that is the source of the SIP message is a priority user. When the I-CSCF determines that the user of the UE is a priority user, the I-CSCF preferentially controls the process according to the SIP message over the UE of the general user.
Specifically, even if the I-CSCF is in a congested state, the I-CSCF transmits the SIP message from the UE of the priority user to the S-CSCF without being discarded. On the other hand, the I-CSCF discards the SIP message from the UE of the general user according to a preset congestion rule.

  In addition to the conventional function, the S-CSCF of this embodiment receives frame data including a SIP message from the I-CSCF, and based on priority information given to the SIP message included in the received frame data. Then, it is determined whether or not the user of the UE that has transmitted the SIP message is a priority user. If the S-CSCF determines that the user of the UE is a priority user, the S-CSCF preferentially controls the process according to the SIP message over the UE of the general user.

Specifically, even if the S-CSCF is in a congested state, the S-CSCF does not suspend processing (for example, registration processing or SIP message relay processing) according to the SIP message from the UE of the priority user. Do. On the other hand, when the S-CSCF is in a congested state, the S-CSCF cancels the processing according to the SIP message from the general user's UE according to a preset rule in the congested state.
In addition, the AS of this embodiment has the same function as the conventional one.
On the other hand, the HSS of this embodiment shared by both the EPC network and the IMS network has the same function as the conventional one.

(1-2) Functional Configuration Example of EPC-GW (S-GW and PDN-GW) Next, the functional configuration of the EPC-GW of the present embodiment will be described based on FIG. FIG. 2 is a block diagram illustrating a functional configuration example of the EPC-GW according to the present embodiment. FIG. 2 shows only the components according to the present embodiment of the EPC-GW.
As shown in FIG. 2, the EPC-GW includes a reception unit 10, a data transfer unit 11, an identification information adding unit 12, and a transmission unit 13.
The S-GW receiving unit 10 is configured to receive an SIP message encapsulated as an IP packet transmitted from the SGSN or the eNB. Further, the S-GW receiving unit 10 is configured to receive an SIP message encapsulated as an IP packet transmitted from the PDN-GW.

  Specifically, the S-GW receiving unit 10 receives, for example, an IPv6 or IPv4 packet that is transmitted from the eNB and includes a SIP message such as a “REGISTER” message, an “INVITE” message, and a “MESSAGE” message in the data part. It is configured to receive the encapsulated IPv4 packet. In addition, the S-GW receiving unit 10 receives an IPv4 packet obtained by encapsulating an IPv6 packet or an IPv4 packet that is transmitted from the PDN-GW and includes, for example, an SIP message such as a “200 OK” message or a “401 Unauthorized” message in the data portion. It is configured to receive.

Here, between the eNB and the S-GW, for example, an IPv6 or IPv4 packet including a SIP message or the like in the data part is encapsulated by an IPv4 private address and TEID (Tunnel Endpoint Identifier) and transmitted and received as an IPv4 packet. It has become.
Further, between the S-GW and the PDN-GW, for example, an IPv6 or IPv4 packet including a SIP message or the like in the data portion is encapsulated by an IPv4 private address and GRE (Generic Routing Encapsulation)) Key and transmitted and received as an IPv4 packet. It is supposed to be.

Hereinafter, in the present embodiment, a case will be described as an example in which an IPv6 packet including an SIP message in the data portion is encapsulated with an IPv4 packet.
When the receiving unit 10 of the S-GW receives frame data (hereinafter referred to as “frame data USG”) that includes an IPv4 packet that is encapsulated from an IPv6 packet that includes an SIP message in the data portion, transmitted from the eNB, the received frame data USG Is output to the data transfer unit 11 of the S-GW.

The data transfer unit 11 of the S-GW extracts the encapsulated IPv6 packet from the IPv4 packet included in the input frame data USG. Then, the IPv4 address of the PDN-GW preset as the destination is set as the destination address, the GRE key assigned by the PDN-GW is added, and the IPv6 packet is encapsulated again. Then, frame data including the IPv4 packet (hereinafter referred to as frame data UPG) is generated.
Then, the data transfer unit 11 of the S-GW outputs the generated frame data UPG to the identification information adding unit 12 of the S-GW.

  Further, the data transfer unit 11 of the S-GW transmits frame data (hereinafter referred to as frame data DSG) including an IPv4 packet transmitted (relayed) from the PDN-GW and encapsulating an IPv6 packet including the SIP message in the data portion. Receive. Then, the data transfer unit 11 of the S-GW extracts the encapsulated IPv6 packet from the IPv4 packet included in the received frame data DSG. Further, the data transfer unit 11 of the S-GW sets the IPv4 address of the destination eNB to the extracted IPv6 packet as a destination address, adds the TEID assigned by the eNB, and encapsulates the IPv6 packet again with the IPv4 packet. To do. Then, the data transfer unit 11 of the S-GW generates frame data including the IPv4 packet (hereinafter referred to as frame data DNB). The S-GW data transfer unit 11 outputs the generated frame data DNB to the S-GW transmission unit 13.

On the other hand, when the frame data UPG is input from the S-GW data transfer unit 11, the S-GW identification information adding unit 12 corresponds to the user of the UE that is the transmission source of the SIP message included in the frame data UPG. The priority user setting information is acquired from a memory (not shown).
Here, the priority user setting information is information indicating whether or not the contract user included in the user information held in the HSS is a priority user. The S-GW and the PDN-GW acquire user information including priority user setting information when registering the UE in the EPC network, and hold the acquired user information in a memory.

When the priority user setting information is acquired, the identification information adding unit 12 of the S-GW determines whether or not the user of the UE that has transmitted the SIP message is a priority user based on the priority user setting information. Based on the determination result, the identification information adding unit 12 of the S-GW identifies for identifying whether or not the user of the UE that has transmitted the SIP message is a priority user in the frame data UPG including the SIP message. Give information.
In the present embodiment, the identification information adding unit 12 of the S-GW includes identification information in a protocol header of a communication protocol corresponding to a preset layer among protocol headers of communication protocols corresponding to each layer constituting the frame data UPG. Is configured to grant.

The identification information adding unit 12 of the S-GW outputs the frame data UPG to which the identification information has been added (hereinafter referred to as frame data UPGI) to the transmitting unit 13 of the S-GW.
The S-GW transmission unit 13 transmits the frame data UPGI input from the S-GW identification information adding unit 12 to the P-CSCF indicated by the IPv4 destination address. In addition, the transmission unit 13 of the S-GW transmits the frame data input from the data transfer unit 11 of the S-GW to the destination (eNB, SGSN) indicated by the IPv4 destination address.

On the other hand, the receiving unit 10 of the PDN-GW is configured to receive the frame data UPGI transmitted from the S-GW. Furthermore, it is configured to receive frame data including, for example, a SIP message transmitted from the P-CSCF.
Specifically, the receiving unit 10 of the PDN-GW transmits frame data including, for example, SIP messages such as “REGISTER” message, “INVITE” message, and “MESSAGE message” of SIP transmitted from the S-GW in the data part. It is configured to receive UPGI. Further, the receiving unit 10 of the PDN-GW is configured to receive frame data including SIP messages such as “401 Unauthorized” message and “200 OK” message transmitted from the P-CSCF.

When receiving the frame data UPGI transmitted from the S-GW, the receiving unit 10 of the PDN-GW outputs the received frame data UPGI to the data transfer unit 11 of the PDN-GW.
The data transfer unit 11 of the PDN-GW extracts the encapsulated IPv6 packet from the IPv4 packet included in the input frame data UPGI. Then, the data transfer unit 11 of the PDN-GW generates frame data UCF including the extracted IPv6 packet. Specifically, the data transfer unit 11 of the PDN-GW generates frame data UCF whose destination is the IPv6 global address of the P-CSCF designated as the destination.

At this time, the data transfer unit 11 of the PDN-GW extracts the identification information included in the protocol header of the communication protocol corresponding to the preset layer of the input frame data UPGI, and extracts the extracted identification information and the generated frame The data UCF is output to the identification information adding unit 12 of the PSN-GW.
Further, when the data transfer unit 11 of the PDN-GW receives an IPv6 packet that is transmitted (relayed) from the P-CSCF and includes the SIP message in the data unit, the data transfer unit 11 sets the IPv4 address of the S-GW as a destination address. -Add the GRE Key assigned by the GW and encapsulate the IPv6 packet. Then, frame data (frame data DSG) including this IPv4 packet is generated. The data transfer unit 11 of the PDN-GW outputs the generated frame data DSG to the transmission unit 13 of the PDN-GW.

  When the identification information and the frame data UCF are input from the data transfer unit 11 of the PDN-GW, the identification information adding unit 12 of the PDN-GW receives the SIP message included in the frame data UCF based on the input identification information. It is determined whether the user of the transmission source UE is a priority user. Based on the determination result, the identification information adding unit 12 of the PDN-GW identifies, in the frame data UCF including the SIP message, whether or not the user of the UE that has transmitted the SIP message is a priority user. Give information.

In the present embodiment, the identification information adding unit 12 of the PDN-GW includes a protocol header corresponding to a layer to which the S-GW has assigned identification information, among protocol headers of communication protocols corresponding to each layer constituting the frame data UCF. The identification information is added to the same or equivalent protocol header.
The identification information adding unit 12 of the PDN-GW outputs frame data UCF (hereinafter referred to as first frame data UCFI) to which the identification information is added to the transmitting unit 13 of the PDN-GW.

The transmission unit 13 of the PDN-GW transmits the first frame data UCFI input from the identification information adding unit 12 of the PDN-GW to the P-CSCF indicated by the destination address of the IP header.
Also, the PDN-GW transmission unit 13 transmits the frame data DSG input from the PDN-GW data transfer unit 11 to the S-GW indicated by the destination address of the IP header.
Although not shown, the EPC-GW includes a computer system for executing the above functions using software and executing software for controlling hardware necessary for realizing each function.

  Such a computer system includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an input / output interface (I / F), and a bus. The CPU, RAM, ROM, and input / output I / F are connected to a bus, and data can be transmitted and received between these connected devices via the bus. Although not shown, the EPC-GW includes a storage device, a display device, an input device, and a communication device connected via an input / output I / F.

(1-3) Functional Configuration Example of CSCF (P-CSCF, I-CSCF, and S-CSCF) Next, the functional configuration of the CSCF of this embodiment will be described based on FIG. FIG. 3 is a block diagram illustrating an example of a functional configuration of the CSCF of the present embodiment. FIG. 3 shows only components according to the present embodiment among CSCFs (P-CSCF, I-CSCF, and S-CSCF).
As shown in FIG. 3, the CSCF includes a receiving unit 20, a SIP message processing unit 21, and a transmitting unit 24.
The SIP message processing unit 21 includes a determination unit 22 and a control unit 23.

The receiving unit 20 of the P-CSCF is configured to receive the first frame data UCFI transmitted from the PDN-GW. Further, the receiving unit 20 of the P-CSCF is configured to receive frame data including an SIP message transmitted from the I-CSCF.
Specifically, the receiving unit 20 of the P-CSCF receives first frame data UCFI including SIP messages such as “REGISTER” message, “INVITE” message, and “MESSAGE” message transmitted from the PDN-GW, for example. Receive. Further, the receiving unit 20 of the P-CSCF receives frame data including SIP messages such as “401 Unauthorized” message and “200 OK” message transmitted from the I-CSCF, for example.

When receiving the first frame data UCFI transmitted from the PDN-GW, the receiving unit 20 of the P-CSCF outputs the received first frame data UCFI to the SIP message processing unit 21 of the P-CSCF.
The SIP message processing unit 21 of the P-CSCF determines whether the user of the UE that has transmitted the SIP message is a priority user based on the identification information included in the preset protocol header of the input first frame data UCFI in the determination unit 22. It is determined whether or not. The determination unit 22 of the P-CSCF outputs the determination result and the first frame data UCFI to the control unit 23 of the P-CSCF.

When the determination result and the first frame data UCFI are input from the determination unit 22 of the P-CSCF, the P-CSCF control unit 23 responds to the SIP message included in the first frame data UCFI based on the determination result. Control the processing.
Specifically, the control unit 23 of the P-CSCF performs processing according to the SIP message from the UE determined to be a priority user, rather than processing according to the SIP message from the UE determined to be a general user. Implement priority control to control with priority. For example, when the P-CSCF is in a congested state, the control unit 23 of the P-CSCF preferentially transmits (relays) the SIP message from the priority user UE to the I-CSCF without discarding the SIP message. To implement.

On the other hand, the control unit 23 of the P-CSCF is a normal control that is set in advance for the general user for the process corresponding to the SIP message from the UE that is determined to be a general user (not a priority user). Implement control. For example, when the P-CSCF is in a congestion state, control is performed such as discarding the SIP message from the UE of the general user according to a preset congestion rule.
Also, the control unit 23 of the P-CSCF receives frame data including the SIP message from the UE of the priority user that sets the selected I-CSCF as the destination regardless of whether or not the P-CSCF is congested. The P-CSCF transmitting unit 24 outputs the P-CSCF in preference to that of a general user UE.

At this time, the control unit 23 of the P-CSCF sets the value of the CPC parameter included in the from header of the SIP message to be transmitted based on the identification information given to the preset protocol header of the first frame data UCFI.
Specifically, when the control unit 23 of the P-CSCF determines that the user of the SIP message transmission source UE is a priority user, the value of the CPC parameter is set to a value indicating a preset priority user. . Then, the frame data including the SIP message is output to the transmission unit 24 of the P-CSCF.

On the other hand, when the P-CSCF control unit 23 determines that the SIP message from the general user's UE is to be discarded based on the congestion rule when the P-CSCF is in a congested state. The first frame data UCFI including the SIP message is discarded. In this case, the control unit 23 of the P-CSCF outputs an SIP error response message including the transmission source UE as a destination to the transmission unit 24 of the P-CSCF.
In addition, when the SIP message from the general user's UE is not to be discarded, the P-CSCF control unit 23 sets the pre-selected I-CSCF as a destination and transmits frame data including the message to the P- The data is output to the CSCF transmitter 24.

At this time, the control unit 23 of the P-CSCF sets the value of the CPC parameter included in the from header of the SIP message to be transmitted based on the identification information given to the preset protocol header. Specifically, the value of the CPC parameter is set to a value indicating a general user set in advance. The control unit 23 of the P-CSCF outputs frame data including the SIP message to the transmission unit 24 of the P-CSCF.
Hereinafter, frame data including an SIP message in which the value of the CPC parameter is set to a value indicating a priority user or a general user is referred to as second frame data UCFI without distinguishing the two.

  The transmission unit 24 of the P-CSCF transmits the frame data (second frame data UCFI) including the SIP message from the input PDN-GW to the set destination I-CSCF. The transmission unit 24 of the P-CSCF transmits frame data including the input SIP message from the I-CSCF to the set destination PDN-GW. At this time, the transmission unit 24 of the P-CSCF transmits frame data including the SIP message from the UE of the priority user to the destination in preference to that of the UE of the general user.

  Next, the receiving unit 20 of the I-CSCF is configured to receive frame data including the SIP message (second frame data UCFI) transmitted from the P-CSCF. Furthermore, the receiving unit 20 of the I-CSCF is configured to receive frame data including a Diameter Base Protocol (hereinafter referred to as DBP) message transmitted from the HSS. Still further, the receiving unit 20 of the I-CSCF is configured to receive frame data including a SIP message transmitted from the S-CSCF.

  Specifically, the receiving unit 20 of the I-CSCF receives the second frame data UCFI including SIP messages such as “REGISTER” message, “INVITE” message, and “MESSAGE” message transmitted from the P-CSCF, for example. Receive. Further, the receiving unit 20 of the I-CSCF receives frame data including a “UAA” message of DBP transmitted from the HSS, for example. Furthermore, the receiving unit 20 of the I-CSCF receives frame data including SIP messages such as “401 Unauthorized” message and “200 OK” message transmitted from the S-CSCF, for example.

When receiving the second frame data UCFI transmitted from the P-CSCF, the receiving unit 20 of the I-CSCF outputs the SIP message included in the received second frame data UCFI to the SIP message processing unit 21 of the I-CSCF. To do.
The SIP message processing unit 21 of the I-CSCF determines whether the user of the UE that is the transmission source of the SIP message is based on the setting value of the CPC parameter included in the from header of the input SIP message in the determination unit 22 of the I-CSCF. It is determined whether or not the user is a priority user. The determination unit 22 of the I-CSCF outputs the determination result and the SIP message to the control unit 23 of the I-CSCF.

When the determination result and the SIP message are input from the determination unit 22 of the I-CSCF, the control unit 23 of the I-CSCF controls processing according to the SIP message based on the determination result.
Specifically, the control unit 23 of the I-CSCF performs priority control on the SIP message from the UE that is determined to be a priority user. For example, when the I-CSCF is in a congested state, the control unit 23 of the I-CSCF performs control to preferentially transmit the SIP message from the UE of the priority user to the S-CSCF without discarding the message. .

  In addition, for example, when the SIP message from the UE that has been determined to be a priority user is a REGISTER message at the time of initial registration, the control unit 23 of the I-CSCF performs priority control for processing according to this message. . For example, when the S-CSCF is in a congested state, the control unit 23 of the S-CSCF does not discard the REGISTER message at the time of initial registration, but cooperates with the HSS to perform authentication processing according to the REGISTER message. And control related to the initial registration processing such as route setting processing.

In addition, for example, other SIP messages such as a REGISTER message, an INVITE message, and a MESSAGE message at the time of re-registration from the UE that is determined to be a priority user are also included in the SIP message. The corresponding processing (re-registration processing, relay processing to the receiving side, etc.) is controlled in preference to that from the general user's UE.
On the other hand, the control unit 23 of the I-CSCF performs normal control on the SIP message from the UE determined to be a general user. For example, when the I-CSCF is in a congestion state, control is performed such as discarding the SIP message from the UE of the general user according to a preset congestion rule.

  Further, the I-CSCF control unit 23 sets the frame including the SIP message from the UE of the priority user, with the S-CSCF selected in advance as the destination regardless of whether or not the I-CSCF is in a congested state. Data (hereinafter, referred to as third frame data UCFI) is output to the transmission unit 24 of the I-CSCF in preference to that of a general user UE. At this time, the value of the CPC parameter included in the “from” header of the SIP message is retained as the value set by the P-CSCF.

  On the other hand, when the I-CSCF is in a congested state, the control unit 23 of the I-CSCF determines that the SIP message from the general user's UE is to be discarded based on the congestion rules. Then, the SIP message is discarded. In this case, the control unit 23 of the I-CSCF outputs frame data including a SIP error response message set with the source UE as a destination to the transmission unit 24 of the I-CSCF. Further, when the SIP message from the UE of the general user is not to be discarded, the third frame data UCFI including the SIP message in which the S-CSCF selected in advance is set as the destination is transmitted to the I-CSCF transmission unit 24. Output to.

  The transmission unit 24 of the I-CSCF transmits the third frame data UCFI including the input SIP message from the P-CSCF to the destination S-CSCF. Also, the I-CSCF transmission unit 24 transmits the frame data including the input SIP message from the S-CSCF to the destination P-CSCF. At this time, the transmission unit 24 of the I-CSCF transmits frame data including the SIP message from the UE of the priority user to the destination in preference to that of the general user UE.

Next, the receiving unit 20 of the S-CSCF is configured to receive the third frame data UCFI transmitted from the I-CSCF. Further, the receiving unit 20 of the S-CSCF is configured to receive frame data including a DBP message transmitted from the HSS.
Specifically, the receiving unit 20 of the S-CSCF receives, for example, the third frame data UCFI including SIP messages such as “REGISTER” message, “INVITE” message, and “MESSAGE” message transmitted from the I-CSCF. Receive. The S-CSCF receiving unit 20 receives frame data including, for example, a DBP “MAA” message, “SAA” message, and the like transmitted from the HSS.

When receiving the third frame data UCFI transmitted from the I-CSCF, the receiving unit 20 of the S-CSCF sends the SIP message included in the received third frame data UCFI to the SIP message processing unit 21 of the S-CSCF. Output.
In the SIP message processing unit 21 of the S-CSCF, based on the setting value of the CPC parameter included in the from header of the input SIP message, the determination unit 22 determines whether the user of the UE that is the source of the SIP message is a priority user. Determine whether or not. The determination unit 22 of the S-CSCF outputs the determination result and the SIP message to the control unit 23 of the S-CSCF.

When the determination result and the SIP message are input from the determination unit 22 of the S-CSCF, the control unit 23 of the S-CSCF controls processing according to the SIP message based on the determination result.
Specifically, for example, when the SIP message from the UE that is determined to be a priority user is a REGISTER message at the time of initial registration, the control unit 23 of the S-CSCF performs priority control for processing according to this message. To implement. For example, when the S-CSCF is in a congested state, the control unit 23 of the S-CSCF does not discard the REGISTER message at the time of initial registration, but cooperates with the HSS to perform authentication processing according to the REGISTER message. And control related to the initial registration processing such as route setting processing.

In addition, the control unit 23 of the S-CSCF also includes other SIP messages such as a REGISTER message, an INVITE message, and a MESSAGE message at the time of re-registration from the UE determined to be a priority user, in the SIP message. The corresponding processing (re-registration processing, relay processing to the receiving side, etc.) is controlled in preference to that from the general user's UE.
On the other hand, the control unit 23 of the S-CSCF performs normal control on the SIP message from the UE that is determined to be a general user. Specifically, for example, when the S-CSCF is in a congestion state, the SIP message from the UE of the general user is discarded according to a preset congestion rule.

Specifically, when the control unit 23 of the S-CSCF determines that the SIP message is to be discarded, the S-CSCF control unit 23 discards the SIP message. In this case, the control unit 23 of the S-CSCF outputs frame data including a SIP error response message set to the transmission source UE to the transmission unit 24 of the S-CSCF. In addition, when the SIP message from the general user's UE is not a target to be discarded, the control unit 23 of the S-CSCF controls the processing corresponding to the SIP message in the same manner as in the normal time.
Note that the control unit 23 of the S-CSCF performs processing corresponding to the SIP message from the UE of the priority user on the SIP message from the UE of the general user regardless of whether or not the S-CSCF is in a congested state. Control is given priority over the corresponding processing.

The transmission unit 24 of the S-CSCF transmits frame data including the SIP message input from the control unit 23 of the S-CSCF to the destination (I-CSCF). In addition, the transmission unit 24 of the S-CSCF transmits frame data including the DBP message input from the control unit 23 of the S-CSCF to the destination (HSS). At this time, the transmission unit 24 of the S-CSCF transmits frame data including the SIP message or DBP message from the UE of the priority user to the destination in preference to that of the general user UE.
Although not shown, the CSCF includes a computer system for realizing the functions described above using software and executing software for controlling hardware necessary for realizing the functions.

  Such a computer system includes a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an input / output interface (I / F), and a bus. The CPU, RAM, ROM, and input / output I / F are connected to a bus, and data can be transmitted and received between these connected devices via the bus. Although not shown, the EPC-GW includes a storage device, a display device, an input device, and a communication device connected via an input / output I / F.

(2) Processing procedure of each process performed by CPU (2-1) Processing procedure of identification information adding process performed by CPU of S-GW Next, identification information performed by CPU of S-GW based on FIG. A processing procedure of the grant process will be described. FIG. 4 is a flowchart illustrating an example of a processing procedure of identification information addition processing performed by the CPU of the S-GW.
Note that the identification information adding process shown in FIG. 4 is repeatedly executed at a preset cycle.
When the dedicated program is executed by the S-GW CPU and the identification information providing process is started, the process proceeds to step S100 as shown in FIG.

In step S100, the receiving unit 10 of the S-GW determines whether or not the frame data USG transmitted from the eNB or SGSN has been received. If it is determined that the frame data USG has been received (Yes), the received frame data USG is output to the data transfer unit 11 of the S-GW, the process proceeds to step S102, and if not (No) ) Ends the series of processing.
When the process proceeds to step S102, the data transfer unit 11 of the S-GW generates frame data UPG for transmission to the PDN-GW based on the input frame data USG. Then, the generated frame data UPG is output to the transmission unit 13 of the S-GW, and the process proceeds to step S104.

  Specifically, the data transfer unit 11 of the S-GW extracts an IPv6 packet from the IPv4 packet included in the frame data USG input from the reception unit 10. Then, an IPv4 header including the IPv4 private address of the destination PDN-GW and the GRE Key are added to the extracted IPv6 packet, and the IPv6 packet is encapsulated again. Further, a layer 2 protocol header (for example, a MAC header) is added to the IPv4 packet to generate frame data UPG (for example, a MAC frame) for transmission.

In step S104, the priority corresponding to the user of the transmission source UE is stored in the memory based on the identification information of the transmission source UE of the SIP message included in the received frame data USG in the identification information providing unit 12 of the S-GW. The user setting information is acquired, and the process proceeds to step S106.
In step S106, based on the priority user setting information acquired in step S104, the identification information adding unit 12 of the S-GW adds the frame data UPG including the SIP message relayed to the PDN-GW to the UE that is the transmission source of the message. Identification information for identifying whether or not the user is a priority user is given. Then, the frame data UPGI having the configuration in which the identification information is added to the frame data UPG is output to the transmission unit 13 of the S-GW, and the process proceeds to step S108.

In this embodiment, the identification information adding unit 12 of the S-GW adds identification information to a protocol header of a preset communication protocol included in the frame data UPG relayed to the PDN-GW.
Specifically, the identification information adding unit 12 of the S-GW adds identification information to the protocol header of a preset communication protocol among the communication protocols of layers 1 to 3 (L1 / L2, IP). Yes.

Here, FIG. 5A is a diagram illustrating an example of frame data UPG transmitted / received between S-GW and PDN-GW, and FIG. 5B is transmitted / received between PDN-GW and P-CSCF. It is a figure which shows an example of the frame data performed. FIG. 5C is a diagram illustrating an example of adding identification information to the MAC header, and FIG. 5D is a diagram illustrating an example of adding identification information using the DS field of the IP header. is there.
As shown in FIG. 5A, the frame data UPG transmitted from the S-GW to the PDN-GW includes a MAC header, an IP header, and a GRE Key. With these headers, an IPv6 packet including an IPv6 header, a TCP / UDP header, and an SIP message included in the frame data UPG is encapsulated.

First, an example in which identification information is added to the MAC header of the frame data UPG will be described.
As shown in FIG. 5C, a field for setting priority is provided in advance as an extension field in the MAC header. And the identification information provision part 12 of S-GW provides identification information by setting the parameter of this field based on priority user setting information.
Specifically, when the identification information adding unit 12 of the S-GW determines that the user is a priority user, the parameter for setting the priority of the extension field is set to a numerical value indicating the preset priority user. On the other hand, when the identification information adding unit 12 of the S-GW determines that the user is a general user, the parameter for setting the priority of the extended field is set to a numerical value indicating the preset general user.

Next, an example in which identification information is added to the IP header of the frame data UPG will be described.
In the IPv4 and IPv6 headers, a DS (Differentiated Service: DiffServ) field for setting priorities is conventionally set. In the DS field, as shown in FIG. 5D, the first 6 bits are bits for setting priority, and the remaining 2 bits are reserved bits.
Specifically, if the identification information providing unit 12 of the S-GW determines that the user is a priority user, a parameter (DSCP (DiffServ Code Point)) for setting the priority of the DS field is set as a priority user set in advance. Set to the number shown. On the other hand, when the identification information adding unit 12 of the S-GW determines that the user is a general user, the SSCP is set to a numerical value indicating the preset general user.

With this configuration, in the present embodiment, for example, even if the identification information indicating the priority user is illegally given to the frame data USG including the SIP message from the UE of the unauthorized user who is not the priority user, the S-GW In the identification information provision part 12, based on priority user setting information, it can re-assign to correct identification information.
Returning to FIG. 4, in step S <b> 108, the transmission unit 13 transmits frame data (frame data UPGI) including the SIP message and provided with identification information to the destination PDN-GW. Thereafter, the series of processing is terminated.

(2-2) Processing Procedure of Identification Information Adding Process Performed by CPU of PDN-GW Next, a processing procedure of identification information adding process performed by the CPU of PDN-GW will be described with reference to FIG. FIG. 6 is a flowchart illustrating an example of a processing procedure of identification information addition processing performed by the CPU of the PDN-GW.
Note that the identification information adding process shown in FIG. 6 is repeatedly executed at a preset cycle.
When the dedicated program is executed by the PDN-GW CPU and the identification information providing process is started, the process proceeds to step S200 as shown in FIG.

In step S200, the PDN-GW receiving unit 10 determines whether or not the frame data UPGI transmitted from the S-GW has been received. If it is determined that the frame data UPGI has been received (Yes), the received frame data UPGI is output to the data transfer unit 11 of the PDN-GW, the process proceeds to step S202, and if it is not determined (No) ) Ends the series of processing.
Here, an IP packet (for example, an IPv6 packet) including an SIP message transmitted from the S-GW is relayed as an IPv4 packet encapsulated by the IPv4 header between the S-GW and the PDN-GW. That is, since data is mainly relayed between S-GW and PDN-GW, processing is mainly performed by software corresponding to each protocol of layers 1 to 3.

When the process proceeds to step S202, when the data transfer unit 11 of the PDN-GW receives frame data (frame data UPGI) including an IPv4 packet encapsulated in the IPv6 packet, the data transfer unit 11 extracts the IPv6 packet from the frame data UPGI. Then, frame data UCF for transmission to the destination P-CSCF including the extracted IPv6 packet in the data portion is generated, and the process proceeds to step S204.
In step S204, the data transfer unit 11 of the PDN-GW extracts identification information from the frame data UPGI received in step S200. Then, the frame data UCF generated in step S202 and the extracted identification information are output to the identification information adding unit 12 of the PDN-GW. Thereafter, the process proceeds to step S206.

Specifically, the data transfer unit 11 of the PDN-GW extracts identification information given to a preset protocol header from the MAC header and IPv4 header included in the frame data UPGI.
Specifically, the data transfer unit 11 of the PDN-GW generates frame data UCF configured as shown in FIG. 5B as frame data to be transmitted from the PDN-GW to the P-CSCF.
Here, the frame data UCF includes a MAC header, an IPv6 header, a TCP / UDP header, a SIP message, and an FCS (Frame Check Sequence) as shown in FIG. 5B. . That is, the MAC header and FCS are added to the IPv6 packet extracted from the frame data UPGI.

Returning to FIG. 6, in step S206, the identification information adding unit 12 of the PDN-GW identifies the same type of protocol header (preset protocol header) as that extracted in the frame data UCF based on the extracted identification information. The first frame data UCFI is generated by adding information. Then, the generated first frame data UCFI is output to the transmission unit 13, and the process proceeds to step S208.
In the present embodiment, in the S-GW, identification information is assigned using an extension field of the MAC header or a DS field of the IP header.

  Therefore, the identification information adding unit 12 of the PDN-GW is the same type as the protocol header from which the identification information is extracted by the data transfer unit 11 of the PDN-GW out of the MAC header or IPv6 header of the frame data UCF based on the extracted identification information. The identification information is given to the header. That is, the identification information is assigned to the same type of protocol headers to which the identification information is assigned by the S-GW among the layer 1 to 3 protocol headers (MAC header, IP header).

  Specifically, when the data transfer unit 11 extracts the identification information from the IPv4 header of the frame data UPGI, the PDN-GW identification information adding unit 12 uses the DS field of the IPv6 header that is the same type of protocol header in the frame data UCF. Parameter (DSCP value) is set to the same value as the extracted identification information or a corresponding value. On the other hand, when the data transfer unit 11 extracts the identification information from the MAC header of the frame data UPGI, the identification information adding unit 12 of the PDN-GW sets the parameter of the extension field for setting the priority of the MAC header of the frame data UCF. Set to the same or corresponding value as the extracted identification information.

In step S208, the transmission unit 13 of the PDN-GW receives the first frame data UCFI including the SIP message and provided with the identification information, which is input from the identification information adding unit 12 of the PDN-GW, as the destination P-CSCF. Send to. Thereafter, the series of processing is terminated.
As a result, in the P-CSCF, software corresponding to the SIP of layers 5 to 7 is identified by the PDN-GW among the protocol headers (MAC header and IP header) of layers 1 to 3 included in the first frame data UCFI. Is controlled according to the SIP message included in the first frame data UCFI.

(2-3) SIP Message Control Processing Procedure Performed by CSCF CPU Next, based on FIG. 7, the SIP message control processing procedure performed by the P-CSCF, I-CSCF and S-CSCF CPU explain. FIG. 7 is a flowchart illustrating an example of a processing procedure of the SIP message control process.
Note that the SIP message control process shown in FIG. 7 is repeatedly executed at a preset cycle.
When the dedicated program is executed by the CPU of the CSCF and the SIP message control process is started, the process first proceeds to step S300 as shown in FIG.

In step S300, the receiving unit 20 determines whether or not the frame data UCFI including the SIP message and attached with the identification information has been received. If it is determined that the frame data UCFI has been received (Yes), the received frame data UCFI is output to the SIP message processing unit 21, the process proceeds to step S302, and if not (No), A series of processing ends.
Specifically, the receiving unit 20 of the P-CSCF determines whether or not the first frame data UCFI transmitted from the PDN-GW has been received. Further, the receiving unit 20 of the I-CSCF determines whether or not the second frame data UCFI transmitted from the P-CSCF is received, and the receiving unit 20 of the S-CSCF receives the second frame data UCFI transmitted from the I-CSCF. It is determined whether or not 3-frame data UCFI has been received.

When the process proceeds to step S302, the determination unit 22 of the SIP message processing unit 21 extracts identification information from the input frame data UCFI, and the process proceeds to step S304.
Specifically, the determination unit 22 of the P-CSCF extracts identification information given to a preset protocol header from the MAC header and the IPv6 header included in the first frame data UCFI.

On the other hand, the determination unit 22 of the I-CSCF extracts identification information (CPC parameter value) given to the from header of the SIP message from the SIP message included in the second frame data UCFI.
Further, the determination unit 22 of the S-CSCF extracts identification information (CPC parameter value) given to the from header of the SIP message from the SIP message included in the third frame data UCFI.

  In step S304, based on the extracted identification information, the determination unit 22 determines whether or not the user of the UE that has transmitted the SIP message is a priority user. If it is determined that the user is the priority user (Yes), the determination result indicating that the user is the priority user and the SIP message included in the frame data UCFI are output to the control unit 23, and the process proceeds to step S306. On the other hand, if it is determined that the user is not a priority user (general user) (No), the determination result indicating that the user is a general user and the SIP message included in the frame data UCFI are output to the control unit 23, and step S308 is performed. Migrate to

When the process proceeds to step S306, the control unit 23 performs priority control based on the input determination result indicating the priority user and the SIP message. Thereafter, the series of processing is terminated.
Specifically, the control unit 23 of the P-CSCF performs control to relay the SIP message input from the determination unit 22 to the destination I-CSCF in preference to that of the general user.

That is, the control unit 23 of the P-CSCF implements a control in which the order of relaying the SIP message from the UE of the priority user is made earlier than that of the general user. In addition, even if the P-CSCF is in a congested state, control is performed to relay the SIP message from the UE of the priority user to the destination I-CSCF without being discarded.
In this embodiment, the control unit 23 of the P-CSCF responds to the SIP message (request message) of the priority user relayed to the I-CSCF, and receives the SIP message (response) transmitted via the I-CSCF. The message is also controlled to be relayed preferentially to the destination EPC-GW without being discarded.

In addition, the control unit 23 of the I-CSCF performs control to relay the SIP message input from the determination unit 22 to the destination S-CSCF in preference to that of the general user.
That is, the control unit 23 of the I-CSCF implements control in which the order of relaying the SIP message from the UE of the priority user is made earlier than that of the general user. In addition, even if the I-CSCF is in a congested state, control is performed to relay the SIP message from the UE of the priority user to the destination S-CSCF without being discarded.

In this embodiment, the control unit 23 of the I-CSCF responds to the SIP message (request message) of the priority user relayed to the S-CSCF, and receives the SIP message (response) transmitted via the S-CSCF. Message) is also controlled to be relayed preferentially to the destination PDN-GW without being discarded.
Moreover, in this embodiment, the control part 23 of I-CSCF gives priority also to the process performed according to the SIP message from UE of a priority user. Specifically, for example, in response to reception of a REGISTER message at the time of initial registration from the UE of the priority user, for initial registration such as destination S-CSCF selection processing and route setting processing performed in cooperation with the HSS. Such processing is preferentially controlled.

Moreover, in this embodiment, the control part 23 of S-CSCF controls the process performed according to the received SIP message in preference to that of a general user.
Specifically, the control unit 23 of the S-CSCF, for example, performs initial processing such as authentication processing and path setting processing performed in cooperation with the HSS in response to reception of a REGISTER message at the time of initial registration from the priority user's UE. The process related to registration is preferentially controlled.
On the other hand, when it is determined in step S304 that the user is not a priority user and the process proceeds to step S308, the control unit 23 performs normal control. Thereafter, the series of processing is terminated.

Specifically, the control unit 23 performs normal control for processing according to the SIP message from the general user's UE. For example, when the CSCF is in a congested state, control such as discarding the SIP message is performed in accordance with a preset congestion rule. When the SIP message from the general user's UE is discarded, the control unit 23 transmits (replies) an SIP error response message to the general user's UE.
Further, when the CSCF is not in a congested state or when the SIP message is not discarded, the control unit 23 performs processing control according to the SIP message of the general user as usual.

(3) Operation Example of Communication System 1 Next, an operation example of the communication system 1 of the present embodiment will be described based on FIG. 8 with reference to FIG. 4, FIG. 6, and FIG.
Here, FIG. 8 is a sequence diagram including operations from when the priority user UE turns the power OFF to ON until the initial registration process to the IMS network is completed.

As shown in FIG. 8, when the power of UEA (here, LTE-compatible mobile communication terminal), which is the UE of the user A who is the priority user, is switched from OFF to ON, the UEA is first registered in the EPC network. Existing processing is executed (step S1000). By this registration process, the transmission path of the IP packet from the radio access system where the UE is located to the PDN-GW is set. At this time, the user information of the priority user A is held in the S-GW and the PDN-GW.
When the transmission path of the IP packet is set, the UEA then transmits a REGISTER message for initial registration of itself to the IMS network toward the EPC-GW set as the transmission path (step S1002).

When the EPC-GW receives frame data including a REGISTER message at the time of initial registration from the UEA that relays to the P-CSCF, the EPC-GW performs identification information addition processing on the frame data (step S1004).
First, in the S-GW, frame data (frame data USG) obtained by encapsulating the IPv6 packet including the REGISTER message at the time of initial registration transmitted from the eNB with the IPv4 header and the TEID is received (Yes in step S100).

When the reception unit 10 receives the frame data USG, the S-GW then extracts an IPv6 packet from the received frame data USG at the data transfer unit 11. Then, the extracted IPv6 packet is encapsulated again with the IPv4 header and the GRE key, and frame data (frame data UPG) for transmission to the PDN-GW is generated (step S102).
Subsequently, the S-GW assigns identification information to the frame data UPG in the identification information adding unit 12 (steps S104 to S106).
Here, identification information is given to the DS field of the IPv4 header included in the frame data UPG.

  That is, the S-GW acquires the priority user setting information of the user A from the memory in the identification information adding unit 12 (step S104), and based on the acquired priority user setting information, the DS included in the IPv4 header of the frame data UPG. The DSCP value of the field is set to a value indicating a preset priority user. In this way, frame data (frame data UPGI) to which identification information is added is generated (step S106). Then, the generated frame data UPGI is transmitted to the PDN-GW set as a transmission path by the S-GW transmission unit 13 (step S108).

When the receiving unit 10 receives the frame data UPGI from the S-GW (Yes in step S200), the PDN-GW extracts the IPv6 packet from the received frame data UPGI in the data transfer unit 11. Then, a new MAC header is added to the extracted IPv6 packet to generate frame data (frame data UCF) for transmission to the P-CFCS (step S202).
Subsequently, in the data transfer unit 11, the PDN-GW extracts identification information (DSCP value) from the DS field of the IPv4 header of the frame data UPGI (step S204). Then, the PDN-GW gives the identification information to the frame data UCF based on the extracted identification information in the identification information adding unit 12 (step S206).

  Specifically, the PDN-GW sets the DSCP value of the DS field included in the IPv6 header of the frame data UCF to the same or corresponding value as the extracted identification information (DSCP value) in the identification information adding unit 12. To give identification information. In this way, the first frame data UCFI having the configuration in which the identification information is added to the frame data UCF is generated. The first frame data UCFI is transmitted to the destination P-CSCF by the PDN-GW transmitting unit 13 through the processing of step S208 (step S1006).

On the other hand, when receiving the first frame data UCFI transmitted from the PDN-GW via the receiving unit 20, the P-CSCF performs SIP message control processing on the received first frame data UCFI (step S1008). ). As shown in FIG. 8, here, it is assumed that the P-CSCF is in a congested state.
When the determination unit 22 of the SIP message processing unit 21 determines that the P-CSCF has received the first frame data UCFI including the SIP message (REGISTER message at the time of initial registration) (Yes in step S300), the reception is then performed. Identification information is extracted from the first frame data UCFI (step S302).

Specifically, the determination unit 22 of the P-CSCF SIP message processing unit 21 extracts the DSCP value from the DS field of the IPv6 header included in the first frame data UCFI.
Subsequently, the P-CSCF, in the determination unit 22, determines whether or not the user A of the UEA that is the transmission source of the REGISTER message at the time of initial registration is a priority user based on the extracted identification information (DSCP value) (Step S22). S304). Here, since the REGISTER message at the time of initial registration included in the received first frame data UCFI is a message transmitted from the UE of the user A who is the priority user, the DSCP value is a value indicating the priority user. .

Therefore, the determination unit 22 of the P-CSCF determines that the user A of the UEA that is the transmission source of the REGISTER message at the time of initial registration is a priority user (Yes in step S304).
Subsequently, when the control unit 23 of the P-CSCF determines that the user of UEA is a priority user based on the determination result of the determination unit 22, the control unit 23 prioritizes the initial registration process according to the REGISTER message at the time of initial registration. Control is performed (step S306).

Specifically, the control unit 23 of the P-CSCF gives priority to the process of relaying the REGISTER message at the time of initial registration to the destination I-CSCF. That is, since the P-CSCF control unit 23 is currently in a congested state, the P-CSCF control unit 23 does not discard the REGISTER message according to the rules at the time of congestion, and more than that of a general user. Preferentially, the REGISTER message is relayed to the destination I-CSCF (step S1010).
At this time, the control unit 23 of the P-CSCF sets the value of the CPC parameter included in the from header of the REGISTER message to a value indicating the priority user. In this way, priority information is given to the REGISTER message. Then, the transmission unit 24 of the P-CSCF transmits frame data (second frame data UCFI) including the REGISTER message to which the priority information indicating the priority user is given to the destination I-CSCF.
Next, when the I-CSCF receives the second frame data UCFI transmitted from the P-CSCF via the receiving unit 20, the I-CSCF performs a SIP message control process on the received second frame data UCFI (step). S1012).

Specifically, if the I-CSCF determines that the receiving unit 20 has received the second frame data UCFI including the REGISTER message at the time of initial registration (Yes in step S300), then the SIP message processing unit 21 In the determination unit 22, identification information is extracted from the received second frame data UCFI (step S302).
That is, the determination unit 22 of the I-CSCF extracts the CPC parameter value included in the from header of the message from the REGISTER message at the time of initial registration included in the second frame data UCFI.

Subsequently, in the determination unit 22, the I-CSCF determines whether the user A of the UEA that is the transmission source of the REGISTER message at the time of initial registration is a priority user based on the extracted identification information (CPC parameter value) ( Step S304).
Here, since the CPC parameter value is a value indicating the priority user, the determination unit 22 of the I-CSCF determines that the user A of the UEA that is the transmission source of the REGISTER message at the time of initial registration is the priority user. (Yes in step S304).

If the control unit 23 of the I-CSCF determines that the user of UEA is a priority user based on the determination result of the determination unit 22, then the control unit 23 of the SIP message processing unit 21 uses the REGISTER message at the time of initial registration. Priority control is performed for the initial registration process according to the process (step S306).
Specifically, the control unit 23 of the I-CSCF first transmits a DBP message (UAR) to the HSS and a DBP message (UAA) from the HSS in response to the REGISTER message at the time of initial registration corresponding to the priority user. ) Is preferentially performed (step S1014).

Thereby, the control part 23 of I-CSCF acquires the server capability information for selecting S-CSCF from HSS, and based on the acquired server capability information, the S-CSCF which the said I-CSCF possesses beforehand S-CSCF suitable for UEA is selected from the list.
Subsequently, the control unit 23 of the I-CSCF gives priority to the process of relaying the second frame data UCFI including the REGISTER message at the time of initial registration corresponding to the priority user to the S-CSCF selected as the destination. That is, the control unit 23 of the I-CSCF relays the second frame data UCFI to the destination S-CSCF in preference to that of the general user (step S1016).

Next, when the S-CSCF receives the second frame data UCFI transmitted from the I-CSCF via the receiving unit 20, the S-CSCF performs SIP message control processing on the received frame data UCFI (step S1018). .
Specifically, the S-CSCF performs the same process as the SIP message control process of the I-CSCF in step S1012, and the user A of the UEA that is the transmission source of the REGISTER message at the time of initial registration is the priority user. It is determined that there is (steps S300 to S304).

Then, the S-CSCF performs priority control on the initial registration processing according to the second frame data UCFI including the REGISTER message at the time of initial registration corresponding to the priority user in the control unit 23 (step S308).
Specifically, the control unit 23 of the S-CSCF first transmits a DBP message (MAR) to the HSS and a DBP message (MAA) from the HSS in response to the REGISTER message at the time of initial registration corresponding to the priority user. ) Is preferentially performed (step S1020). Thereby, the control unit 23 of the S-CSCF sets the address of the S-CSCF to HSS and acquires the authentication vector of UEA. The control unit 23 of the S-CSCF authenticates the user A of UEA based on this authentication vector.

  Further, the control unit 23 of the S-CSCF transmits an SIP “401 Unauthorized” message including a challenge value to which the UEA will respond to the I-CSCF (step S1022). The I-CSCF relays the received “401 Unauthorized” message to the P-CSCF (step S1024), and the P-CSCF relays the received “401 Unauthorized” message to the EPC-GW (step S1026). ). Then, the EPC-GW relays the received “401 Unauthorized” message to UEA (step S1028).

In response to receiving the “401 Unauthorized” message, the UEA generates an appropriate response (credit information) to the challenge value included in the message. Then, a new REGISTER message including this credit information is transmitted to the EPC-GW (step S1030).
In the EPC-GW, an identification information adding process is performed on the frame data including the REGISTER message from the UEA relayed to the P-CSCF (step S1032).
Here, the identification information providing process in step S1032 is the same as that in step S1004, and a description thereof will be omitted.

Through the processing in step S1032, the frame data (first frame data UCFI) including the new REGISTER message including the credit information and provided with the identification information is transferred to the destination P-CSCF by the transmission unit 13 of the PDN-GW. It is transmitted (step S1034).
Here, the processing from the subsequent steps S1036 to S1040 is the same as the processing from the above steps S1008 to S1012, and a description thereof will be omitted.
If the I-CSCF determines that the user A of the UEA is a priority user through step S1040, the I-CSCF performs registration processing according to the new REGISTER message included in the second frame data UCFI received from the P-CSCF. Implement priority control.

Specifically, the control unit 23 of the I-CSCF first performs the DBP message (UAR) transmission processing to the HSS and the HSS in accordance with the new REGISTER message including the credit information included in the second frame data UCFI. The DBP message (UAA) reception process from the server is prioritized (step S1042).
Here, the difference from the step S1014 is that the address of the S-CSCF assigned to the user A registered in the HSS by the DBP message (MAR) in the step S1020 is the DBP message (UAA) received from the HSS. It is included.
Thereby, the control part 23 of I-CSCF transmits the 2nd frame data UCFI to S-CSCF of the same destination as the time of said step S1016 (step S1044).

Next, when the S-CSCF receives the second frame data UCFI transmitted from the I-CSCF via the receiving unit 20, the S-CSCF performs a SIP message control process on the received second frame data UCFI ( Step S1046).
Here, the process until the UE A user A in the SIP message control process in step S1046 is determined as the priority user is the same process as in the above step S1018, and a description thereof will be omitted.

That is, the S-CSCF performs priority control on the registration process according to the new REGISTER message including the credit information included in the second frame data UCFI in the control unit 23 (step S308).
First, the control unit 23 of the S-CSCF verifies the authentication vector acquired from the HSS in step S1020 with respect to the credit information included in the REGISTER message.

If the authentication is successful by this verification, the control unit 23 of the S-CSCF next performs a DBP message (SAR) transmission process to the HSS and a DBP message (SAA) reception process from the HSS (step S1048). .
Thereby, the control unit 23 of the S-CSCF notifies the HSS that the user has been registered, and acquires (downloads) the user information of the UEA from the HSS.

Next, the control unit 23 of the S-CSCF transmits a SIP “200 OK” message to the I-CSCF in order to indicate that the REGISTER message request is successful (step S1050).
This “200 OK” message includes the URI assigned to the user A and the URI of the SIP server (CSCF) to be passed.

The I-CSCF relays the “200 OK” message received from the S-CSCF to the P-CSCF (step S1052), and the P-CSCF relays the “200 OK” message received from the I-CSCF to the EPC-GW ( Step S1054). Then, the EPC-GW relays the “200 OK” message received from the P-CSCF to the UEA (step S1056).
Thus, the registration process is completed when the UEA receives the “200 OK” message.

  Thereafter, as shown in steps S1058 to S1064, the SIP “INVITE” message transmitted from the UEA is transmitted to the receiving side via the SIP server set as the route. Also for this “INVITE” message, the DSCP value of the DS field of the IP header is set to a value indicating the priority user in the EPC-GW. In addition, in the P-CSCF set as a route, the CPC parameter value included in the “from” header of the “INVITE” message is set to a value indicating the priority user based on the DSCP value of the IP header.

Therefore, this “INVITE” message is identified as a message from UE A of user A who is the priority user from the DSCP value of the IP header or the CPC parameter value of the from header in the SIP server (CSCF) set as a route. be able to. Therefore, even if the SIP server set as a route is in a congested state, it is preferentially relayed to the receiving side without being discarded in the middle.
In addition to the “INVITE” message, similar identification information assignment processing and priority control are performed for other SIP messages such as a “REGISTER” message at the time of re-registration and a “MESSAGE” message at the time of sending an SMS message. The

(4) Operation and Effect In the communication system 1 according to the present embodiment, in the EPC-GW, the UE is sent to the EPC network with respect to the frame data including the SIP message transmitted from the UE to the P-CSCF. Based on the priority user setting information held at the time of registration, identification information for identifying whether the user of the UE is a priority user can be given.
Specifically, the EPC-GW can add identification information to the extension field of the MAC header or the DS field of the IP header included in the received frame data based on the priority user setting information.

On the other hand, the P-CSCF receives the frame data (first frame data UCFI) to which the identification information is added and includes the SIP message from the EPC-GW, and adds the identification information to the received first frame data UCFI. Based on this, it can be determined whether or not the user of the UE that is the source of the SIP message is a priority user.
When the P-CSCF determines that the user is a priority user, the process according to the received SIP message (for example, the relay process of the SIP message to the I-CSCF) can be controlled with priority.

Further, in the P-CSCF, by setting the value of the CPC parameter included in the from header of the SIP message to be relayed to a value according to the determination result based on the determination result as to whether or not the user is a priority user, It is possible to generate frame data (second frame data UCFI) to which priority information for determining whether or not is given.
On the other hand, in the I-CSCF, based on the value of the CPC parameter included in the from header of the SIP message of the received second frame data UCFI, it is determined whether or not the user of the UE that has transmitted the SIP message is a priority user. can do.

If the I-CSCF determines that the user is a priority user, the process according to the received SIP message can be preferentially controlled.
In addition, the S-CSCF receives the third frame data UCFI from the I-CSCF, and based on the CPC parameter value included in the from header of the SIP message of the received third frame data UCFI, the UE that is the transmission source of the SIP message It can be determined whether or not the user is a priority user.

When the S-CSCF determines that the user is a priority user, the process according to the received SIP message can be controlled with priority.
As described above, since the identification information can be given to the frame data including the SIP message in the EPC-GW arranged in the EPC network, the P-CSCF arranged in the IMS network uses the identification information to Whether or not the user of the source UE is a priority user can be identified. Therefore, the P-CSCF can identify whether or not it is a priority user based on the frame data (first frame data UCFI) received from the EPC-GW without using the user information acquired after the initial registration. The effect that the processing load of the determination process can be reduced as compared with the case where user information is used is obtained.

Further, since the identification information is given in the EPC-GW arranged in the EPC network, for example, it is possible to prevent the unauthorized user from impersonating the priority user. Thereby, the effect that priority control can be implemented based on highly reliable identification information is acquired.
In addition, the P-CSCF identifies whether the user sending the SIP message is a priority user based on the identification information given in the EPC-GW before the initial registration process of the UE to the IMS network is completed. can do. Thereby, it is possible to preferentially control the initial registration process corresponding to the message for the REGISTER message at the time of the initial registration. Therefore, even in an environment where the P-CSCF is congested, it is possible to obtain an effect that the initial registration process for the priority user UE can be controlled with priority.

(5) Correspondence with the present invention In the first embodiment described above, the UE corresponds to the communication terminal, the EPC network corresponds to the access network, the EPC-GW corresponds to the relay device, and identification information is added. The unit 12 corresponds to an identification information adding unit.
In the above embodiment, the IMS network corresponds to the service control network, the CSCF corresponds to the control device, the determination unit 22 corresponds to the determination unit, and the control unit 23 corresponds to the control unit.
Moreover, in the said embodiment, step S106, S206 corresponds to an identification information provision step, step S304 corresponds to a determination step, and step S306 corresponds to a control step.

(Second Embodiment)
Next, a second embodiment of a communication system, a relay device, a control information relay program, and a communication method according to the present invention will be described based on the drawings.
In the first embodiment, in the S-GW, identification information is added to frame data for transmission (frame data UPG) including an IPv4 packet obtained by encapsulating an IPv6 packet including a SIP message in a data portion based on priority user setting information. The configuration. In addition, in the PDN-GW, based on the identification information included in the frame data UPG, the identification information is added to the frame data for transmission (frame data UCF) including the IPv6 packet including the SIP message in the data portion. .

In contrast, in the present embodiment, the identification information is not added in the S-GW, but the identification information is added to the frame data UCF based on the priority user setting information only by the PDN-GW. Different from the first embodiment.
Therefore, the configuration of the communication system 1 of the present embodiment is the same as that of the first embodiment except that the contents of the identification information adding process performed in the PDN-GW are partially different and the S-GW has the same configuration as the conventional one. It becomes the structure similar to a form. Hereinafter, only differences from the first embodiment will be described in detail, and description of the same configuration will be omitted as appropriate.

(6) Processing procedure of identification information addition process performed by CPU of PDN-GW Based on FIG. 9, the processing procedure of the identification information provision process performed by CPU of PDN-GW of this embodiment is demonstrated. FIG. 9 is a flowchart illustrating an example of the processing procedure of the identification information providing process of the present embodiment.
In addition, the identification information provision process shown in FIG. 9 is repeatedly performed with the preset period.
When the dedicated program is executed by the PDN-GW CPU and the identification information providing process is started, the process proceeds to step S400 as shown in FIG.
Here, the processes of steps S400 to S402 and S408 are the same as the processes of steps S200 to S202 and S208 of the first embodiment, and a description thereof will be omitted.

Hereinafter, the process of step S404 will be described.
When the process proceeds from step S402 to step S404, the identification information adding unit 12 acquires priority user setting information corresponding to the user of the UE that is the transmission source of the SIP message from the memory, and the process proceeds to step S406.
Note that the priority user setting information acquisition process is acquired in advance when a UE is registered in the EPC network, as in the acquisition process of the identification information adding unit 12 of the S-GW of the first embodiment (not shown). The processing is acquired from the user information held in

  In step S406, based on the priority user setting information acquired in step S404 in the identification information adding unit 12, the frame data (frame data UCF) including the SIP message relayed to the P-CSCF is changed to the UE that has transmitted the message. Identification information for identifying whether or not the user is a priority user is given. Then, the frame data (first frame data UCFI) to which the identification information is added is output to the transmission unit 13, and the process proceeds to step S408.

In the present embodiment, the identification information adding unit 12 adds identification information to a protocol header of a preset communication protocol included in the frame data UCF.
Specifically, the identification information adding unit 12 sets in advance the MAC header corresponding to layers 1 and 2 or the IP header corresponding to layer 3 of the frame data UCF having the configuration shown in FIG. Add identification information to the protocol header.

First, an example in which identification information is added to the MAC header of the frame data UCF will be described.
When the identification information providing unit 12 of the PDN-GW according to the present embodiment determines that the user of the UE that is the transmission source of the SIP message is a priority user, the extension field included in the MAC header of the frame data UCF including the message A parameter for setting the priority is set to a numerical value indicating a preset priority user.
On the other hand, if the identification information adding unit 12 of the PDN-GW according to the present embodiment determines that the user of the SIP message transmission source UE is a general user, the extension included in the MAC header of the frame data UCF including the message The parameter for setting the field priority is set to a numerical value indicating a general user set in advance.

Next, an example in which identification information is added to the IP header of the frame data UCF will be described.
When the identification information providing unit 12 of the PDN-GW according to the present embodiment determines that the user of the UE that is the transmission source of the SIP message is a priority user, the DSCP value of the DS field included in the frame data UCF including the message is determined. , A numerical value indicating a preset priority user is set.
On the other hand, if the identification information providing unit 12 of the PDN-GW according to the present embodiment determines that the user of the UE that is the transmission source of the SIP message is a general user, the DSCP of the DS field included in the frame data UCF including the message The value is set to a numerical value indicating a general user set in advance.

(7) Operation Example of Communication System 1 Next, an operation example of the communication system 1 of the present embodiment will be described based on FIG. 8 with reference to FIG.
In addition, since it becomes the process similar to the said 1st Embodiment except the identification information provision process (step S1004, S1032) performed by EPC-GW, description is abbreviate | omitted.
When the EPC-GW receives the frame data including the REGISTER message at the time of initial registration from the UEA relayed to the P-CSCF, the EPC-GW performs the identification information adding process based on the frame data (step S1004).

Specifically, first, in the S-GW, frame data (frame data USG) obtained by encapsulating the IPv6 packet including the REGISTER message at the time of initial registration, which is transmitted from the eNB, with the IPv4 header and the TEID is received (step S400). Yes).
As a result, the S-GW causes the data transfer unit 11 to extract, from the received frame data, an IPv6 packet including the REGISTER message at the time of initial registration in the data unit. Then, the extracted IPv6 packet is encapsulated again with the IPv4 header and the GRE key to generate frame data UPG. Then, the frame data UPG is transmitted to the PDN-GW set as the transmission path by the transmission unit 13 of the S-GW.

When the PDN-GW receives the frame data UPG from the S-GW, the PDN-GW performs an identification information adding process based on the received frame data UPG.
Specifically, the PDN-GW extracts an IPv6 packet from the received frame data UPG in the data transfer unit 11. Then, frame data UCF including the extracted IPv6 packet is generated (step S402).

  On the other hand, the PDN-GW acquires the priority user setting information of the user A from the memory in the identification information adding unit 12 (step S404), and based on the acquired priority user setting information, the DS of the IPv6 header included in the frame data UCF. The DSCP value of the field is set to a value indicating a preset priority user. In this way, the first frame data UCFI having a configuration in which the identification information is added to the frame data UCF is generated (step S406).

Then, the first frame data UCFI generated in the identification information adding unit 12 is transmitted to the destination P-CSCF by the S-GW transmission unit 13 through the processing in step S408 (step S1006).
Here, the operation of step S1032 of the present embodiment is the same as the operation of step S1004 of the present embodiment, except that the processing target is frame data including a new REGISTER message including credit information. Omitted.

(8) Operation and Effect The communication system 1 according to this embodiment has the following operation and effect in addition to the operation and effect of the first embodiment.
That is, in the communication system 1 according to the present embodiment, whether or not the user of the UE is a priority user for the frame data UCF including the SIP message transmitted from the UE to the P-CSCF in the PDN-GW. The identification information for identifying can be given.
Thereby, since it is not necessary to perform the process of giving identification information in the S-GW, the communication system 1 can be configured at a relatively low cost without any improvement to the existing S-GW. The effect is obtained.

(9) Correspondence with the Present Invention In the second embodiment described above, the EPC network corresponds to the access network, the EPC-GW corresponds to the relay device, and the identification information adding unit 10 includes the identification information adding unit. Corresponding to.
In the above embodiment, the IMS network corresponds to the service control network, the CSCF corresponds to the control device, the determination unit 22 corresponds to the determination unit, and the control unit 23 corresponds to the control unit.
In the above embodiment, step S406 corresponds to the identification information providing step, step S304 corresponds to the determination step, and step S306 corresponds to the control step.

(10) Modification In the first embodiment, for the frame data UPG including the SIP message transmitted from the S-GW to the PDN-GW, the extension field of the MAC header or the IPv4 header included in the frame data UPG However, the present invention is not limited to this configuration.
For example, the configuration may be such that identification information is given using the DS field of the IPv6 header encapsulated by the IPv4 header and the GRE Key. With this configuration, the PDN-GW does not need to perform the process of adding identification information, and thus the communication system 1 is configured at a relatively low cost without any improvement to the existing PDN-GW. The effect that it can be obtained.

Moreover, in each said embodiment, although it was set as the structure which performs priority control in all P-CSCF, I-CSCF, and S-CSCF, it is not restricted to this structure. For example, other configurations such as a configuration in which only the P-CSCF performs priority control and a configuration in which only the P-CSCF and the I-CSCF perform priority control may be employed.
In each of the above embodiments, the access network is an EPC network and the service control network is an IMS network. However, the present invention is not limited to this configuration.

For example, as long as the configuration is connected to a service control network such as an IMS network (for example, NGN (Next Generation Network) based on IMS) via an access network such as an EPC network, other configurations may be used. Good.
In each of the above embodiments, the UE is configured as a mobile communication terminal compatible with the IMS and EPC networks. However, the present invention is not limited to this configuration. For example, another terminal such as a fixed communication terminal connected to the IMS network via an EPC network or an access network different from EPC may be included.

The above embodiments are preferable specific examples of the present invention, and various technically preferable limitations are given. However, the scope of the present invention is described in particular in the above description to limit the present invention. As long as there is no, it is not restricted to these forms. In the drawings used in the above description, for convenience of illustration, the vertical and horizontal scales of members or parts are schematic views different from actual ones.
In addition, the present invention is not limited to the above-described embodiments, and modifications, improvements, equivalents, and the like within the scope that can achieve the object of the present invention are included in the present invention.

DESCRIPTION OF SYMBOLS 1 Communication system 10,20 Reception part 11 Data transfer part 21 SIP message processing part 12 Identification information provision part 13,24 Transmission part 23 Control part UPG, UCF Frame data

Claims (6)

Control information for controlling the predetermined process requested by the communication terminal to be transmitted to and received from the communication terminal and the service control network via the access network. A communication system including a relay device that relays, and a control device that is arranged in the service control network and controls the predetermined processing based on the control information relayed via the relay device,
The relay device is
Based on the priority user setting information that is information indicating whether or not the user of the communication terminal held in advance in the user information holding device is a priority user, the control terminal receives the control information from the communication terminal. An identification information providing unit that provides identification information for identifying whether or not the user is a priority user;
The controller is
A determination unit that determines whether a user of a communication terminal that is a transmission source of the control information is a priority user based on the identification information given to the control information from the relay device;
Based on the determination result of the determination unit, the control information from the communication terminal of the user who has determined that the predetermined processing according to the control information from the communication terminal of the user determined to be a priority user is not a priority user. A control unit that performs control with priority over the predetermined process according to the communication system. Control information for controlling a predetermined process requested by the communication terminal to be transmitted to and received from the communication terminal and the service control network via the access network. A relay device for relaying,
Based on the priority user setting information, which is information indicating whether or not the user of the communication terminal previously held in the user information holding device is a priority user, the user of the communication terminal with respect to the control information from the communication terminal A relay apparatus comprising: an identification information adding unit that adds identification information for identifying whether or not the user is a priority user. Based on user information including the priority user setting information held in the user information holding device, the registration processing of the communication terminal to the access network is controlled,
The identification information adding unit adds the identification information to the control information from the communication terminal based on the priority user setting information included in the user information acquired during registration processing to the access network. The relay device according to claim 2, wherein The access network is a network that controls transmission of IP (Internet Protocol) packets,
The service control network is an IMS (IP Multimedia Subsystem) communication system network,
The control information is a SIP (Session Initiation Protocol) message,
The identification information adding unit adds the identification information to a protocol header of a preset communication protocol among a plurality of hierarchized communication protocols used for relaying the SIP message. The relay device described. Control information for controlling a predetermined process requested by the communication terminal to be transmitted to and received from the communication terminal and the service control network via the access network. A control information relay program executed in a computer provided in a relay device for relaying,
Based on the priority user setting information, which is information indicating whether or not the user of the communication terminal previously held in the user information holding device is a priority user, the user of the communication terminal with respect to the control information from the communication terminal A control information relay program that causes a computer to execute a process comprising an identification information adding step for adding identification information for identifying whether or not a user is a priority user. Control information for controlling a predetermined process requested by the communication terminal to be transmitted to and received from the communication terminal and the service control network via the access network. Communication using a mobile communication system including a relay device that relays and a control device that is arranged in the service control network and controls the predetermined processing based on the control information relayed via the relay device A method,
Based on the priority user setting information for setting whether or not the user of the communication terminal held in the user information holding device in advance is a priority user, the relay device performs the control information from the communication terminal with respect to the control information. An identification information providing step for providing identification information for identifying whether or not the user of the communication terminal is a priority user;
A determination step in which the control device determines whether or not a user of the communication terminal that is a transmission source of the control information is a priority user based on the identification information given to the control information from the relay device;
The communication terminal of the user who has determined that the predetermined processing according to the control information from the communication terminal of the user who is determined to be a priority user based on the determination result of the determination step is not a priority user And a control step of performing control with priority over the predetermined processing according to the control information from the communication method.

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