JP2013239837A - Network node and server - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a network node capable of notifying a confirmation result of UE information along with a load control result of a trigger request.SOLUTION: A network node transmits a device trigger instructing to start an operation to a communication terminal. The network node includes: a trigger request receiving section that receives a trigger request requesting the communication terminal to transmit a device trigger from a server; a UE information confirmation section that confirms whether or not the device trigger can be transmitted to the communication terminal; a load control confirmation section that confirms whether or not the load control has any problem; and a trigger response transmission section that transmits a trigger response to the server after the confirmation of the UE information by the UE information confirmation section and the confirmation of the load control by the load control confirmation section.

Description

  The present invention relates to a communication technology using a cellular communication function, and in particular, a network node that performs communication using a technology of machine-to-machine communication (called Machine to Machine Communication or Machine Type Communication, hereinafter referred to as M2M communication). About.

  The cellular communication function is used not only for voice calls and data communication such as mobile phones and smartphones, but also widely used in devices for M2M communication (also called MTC devices). Cellular communication terminals including MTC devices ( Hereinafter, the number of UEs (described as user equipment (UE) or communication terminals) continues to increase. In order for a user and an application operated by the user (hereinafter referred to as an application server) to start communication with the UE, it is necessary to transmit a message requesting the UE to start communication. As this message, the application server can transmit a message called a device trigger to the UE.

  If the UE that has received the device trigger does not yet have a connection for data communication (referred to as user plane, PDP context, PDN connection, etc.) between the UE and the cellular network, the appropriate procedure (connection, connection establishment, Execute connection activation, bearer establishment, bearer activation, bearer change). These procedures are started by transmitting a control message such as a connection establishment request, a service request, or a bearer establishment request.

  The application server sends a device trigger to any UE, while the UE that has received the device trigger initiates a procedure to make the connections necessary to communicate with the application server available. FIG. 16 is a sequence diagram illustrating the background art regarding the operation of SCS 300 and cellular network entities when transmitting device triggers. The application server 400 requests the SCS (Service Capability Server, also referred to as MTC server) 300 to transmit a device trigger request (hereinafter also referred to as a trigger request) (step S16000), and receives the request. The SCS 300 transmits a device trigger request to an MTC-IWF (Interworking Function, hereinafter referred to as IWF) 210 (step S 16001).

  The IWF 210 that has received the device trigger request performs necessary checks (steps S16003, S16004, and S16005), and then performs processing for transmitting a device trigger to the UE 100 (steps S16007 and S16009). Device triggers include control messages (NAS (Network Access Stratum) messages), SMS (Short Messages), CBS (Cell Broadcast Service), MBMS (Multicast Broadcast Message Service), sent by entities in the cellular network to the UE. Various types of messages such as data packets (IP packets) can be used.

  Receiving the trigger request, the IWF 210 confirms (Authorization) the SCS 300 of the transmission source (Step S 16003). Furthermore, the IWF checks whether or not the trigger request received from the SCS has a load control (the number of transmissions (Submission Quota) does not exceed the specified value, or the transmission frequency (Submission Rate) of the trigger request does not exceed the specified value, Whether the processing load of the IWF is overload (step S16003). If the trigger request transmission frequency exceeds the specified value, the IWF sends a device trigger response that includes a value (Cause Value) indicating that the device trigger could not be transmitted due to a load control problem (Reason of Failure). (Or a device trigger confirmation message (hereinafter referred to as a trigger response)) is transmitted to the SCS (step S16012). On the other hand, if there is no problem with these checks, an inquiry is made to the HLR / HSS (Home Location Register / Home Subscription Server, hereinafter referred to as HSS), and there is no error in the response, or the subscription of the UE included in the response. Information (subscriber information, hereinafter referred to as UE information) is acquired and the content is confirmed (steps S16004 and S16005). Also here, if the UE is not qualified to receive the device trigger as a result of checking the UE information, it includes a value indicating that the device trigger could not be transmitted due to a problem with the UE information (not allowed). A trigger response is transmitted to the SCS (step S16013).

“3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; System Improvements for Machine-Type Communications”, 3GPP TR 23.888, V1.6.1, February 2012. “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Service requirements for machine-type communications”, 3GPP TS 22.368, V11.4.0, March 2012. “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; Architecture Enhancements to facilitate communications with Packet Data Networks and Applications”, 3GPP TS 23.682, V11.0.0, March 2012. “3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network”, 3GPP TS 23.401, V11.1.0, March 2012.

  If the IWF sends a trigger response to the SCS immediately after detecting a problem (exceeding transmission frequency, etc.) in the load control check and notifies that the device trigger could not be sent, the SCS Resend the trigger request. The IWF that has received the retransmitted trigger request again checks the SCS (Authorization) and checks the load control. If there is no problem with this check, the IWF queries the HSS for UE information. If there is a problem with the result of the inquiry to the HSS (if device trigger transmission to the UE is not allowed), a trigger indicating that the device trigger could not be transmitted again for the retransmitted trigger request Returns a response to the SCS. In other words, since the trigger request is retransmitted by the SCS even though the device trigger transmission is not permitted to the UE that is the target of the trigger request in the first place, unnecessary traffic occurs between the SCS and the IWF. A processing load unnecessary for the SCS and the IWF is also generated. Unnecessary traffic causes congestion in the network, and unnecessary processing causes overloading of SCS and IWF and increases in power consumption. In order to solve the above problem, according to an aspect of the disclosed technique, for example, a technique is provided that enables a trigger response to be returned after performing an appropriate check regarding a trigger request.

  In order to achieve the above object, for example, one aspect of the disclosed technique is a network node that transmits a device trigger for instructing a communication terminal to start an operation, and transmits the device trigger to the communication terminal. A trigger request receiving unit for receiving a trigger request for requesting from the server, a UE information confirmation unit for confirming whether there is a problem in the information of the communication terminal, and whether there is a problem in load control of the trigger request A network node having a load control determination unit for confirming whether or not, and a trigger response transmission unit for transmitting to the server a trigger response indicating that there is a problem in load control after receiving a result of the UE information inquiry. With the above-described configuration, for example, an effect that the switching of the gateway can be executed for the connection used for data communication is realized.

  Note that aspects of the disclosed technology may be realized by a communication system, a user terminal, a computer program, or a combination thereof in addition to the network node.

  In addition, the effect and advantage which this indication technique has are not limited above, The further effect and advantage will become clear from the content of an indication of this specification and drawing. The above-described further effects and advantages may be provided individually by the various embodiments and features disclosed in this specification and the drawings, and not all effects and advantages need to be provided.

  According to an aspect of the present disclosure, for example, an effect is realized in which switching of a gateway can be executed for a connection used for data communication.

The figure which shows an example of the network structure in 1st Embodiment of this indication technique. The sequence diagram which shows the 1st example of operation | movement of the main entities in SCS300 and the cellular network 200 in 1st Embodiment of this indication technique. The sequence diagram which shows an example of operation | movement when there exists a problem in the result of the inquiry to HSS260 in 1st Embodiment of this indication technique The sequence diagram which shows the 2nd example of operation | movement of the main entities in SCS300 and the cellular network 200 in 1st Embodiment of this indication technique. The sequence diagram which shows an example of the operation | movement in the case of confirming UE information after confirming the transmission origin of a trigger request in 1st Embodiment of this indication technique. The sequence diagram which shows an example of operation | movement in the case of confirming load control even if there is a problem in UE information in the first embodiment of the present disclosure 6 is a flowchart illustrating an example of processing of the IWF 210 based on the operation described in FIGS. 4, 5, and 6 in the first embodiment of the disclosed technology. The block diagram which shows an example of a structure of IWF210 in 1st Embodiment of this indication technique The sequence diagram which shows an example of operation | movement of the main entities in SCS300 and the network 200 in 2nd Embodiment of this indication technique The sequence diagram which shows the 1st example in case SCS300 in 2nd Embodiment of this indication technique transmits the trigger request with respect to UE100 and UE101, respectively. The sequence diagram in case SCS300 in 2nd Embodiment of this indication technique transmits the trigger request with respect to UE100 The sequence diagram which shows the 2nd example in case SCS300 in 2nd Embodiment of this indication technique transmits the trigger request with respect to UE100 and UE101, respectively The block diagram which shows an example of a structure of SCS300 in 2nd Embodiment of this indication technique The flowchart which shows the process of SCS300 when SCS300 in 2nd Embodiment of this indication technique receives the trigger response which shows the problem by load control. The flowchart which shows an example of the process of IWF210 based on the operation | movement demonstrated in FIG. 2 and FIG. 3 in 1st Embodiment of this indication technique. Sequence diagram showing background art regarding the operation of SCS 300 and cellular network entities when sending device triggers

Hereinafter, the first and second embodiments of the disclosed technology will be described with reference to the drawings.
In the first embodiment of the disclosed technique, when the IWF receives a trigger request, the IWF transmits a trigger response indicating a load control problem after inquiring user information to the HSS. In the second embodiment of the disclosed technology, the SCS that has received a trigger response indicating that trigger transmission cannot be performed by load control is the IWF that is the transmission destination of a trigger request that could not be transmitted and an untransmitted trigger request. Select.

(First embodiment)
First, a first embodiment of the disclosed technique will be described. FIG. 1 is a diagram illustrating an example of a network configuration according to the first embodiment of the disclosed technique. In FIG. 1, a UE 100 that is a cellular communication terminal, a cellular network (also referred to as a core network or a 3GPP network, hereinafter also referred to as a network) 200 to which the UE 100 is connected, and a trigger request addressed to the UE 100 are transmitted. An SCS 300 to perform and an application server (also referred to as an MTC application or simply an application) 400 to perform data communication with the UE 100 are illustrated.

  Also, in FIG. 1, as components of the cellular network 200, IWF (Interworking Function) 210 that connects the cellular network 200 and the SCS 300, management of location information (location) of the UE 100, and communication control of the UE 100 (circuit switching control or packet switching) Control) MME / SGSN / MSC (Mobility Management Entity / Serving GPRS Support Node / Mobile Switching Center) 220, UE 100 for data communication connection management, data transfer to external network, user authentication, QoS control, etc. Between a P-GW / GGSN / ePDG (Packet Data Network Gateway / Gateway GPRS Support Node / evolved Packet Data Gateway) 230, a base station to which the UE 100 is connected (attached) and an entity in the cellular network 200 (for example, P-GW) Connection management and user An S-GW (Serving Gateway) 240 that performs the data transfer, an eNB / NB / BS 250 (evolved Node B / Node B / Base Station) that functions as a base station that provides the UE 100 with a connection point to the cellular network 200, a user HSS / HLR (Home Subscriber Server / Home Location Register) 260 for managing subscription data, SMS-SC (Short Message Service-Service Center, or GMSC / IWMSC) 270 for transmitting SMS to the UE 100, IWF DNS 280 that holds the correspondence between IDs and IP addresses is shown.

  FIG. 1 illustrates an example of a network configuration for realizing the functions defined in 3GPP. However, the network configuration to which the disclosed technology is applied is limited to that illustrated in FIG. Is not to be done. Further, in the following description, the MME / SGSN / MSC 220 illustrated in FIG. 1 is referred to as an MME 220 in order to clarify the technical idea according to the disclosed technology, and the P-GW / illustrated in FIG. GGSN / ePDG230 may be described as P-GW230.

  The SCS 300 requests the IWF 210 to transmit a device trigger addressed to the UE 100 (hereinafter also referred to as a trigger) in order to request the start of data communication by the UE 100 and the transmission of a control message. On the other hand, when receiving a device trigger transmission request from the SCS 300, the IWF 210 transmits the device trigger to the UE 100 via the network 200. As a means for transmitting a device trigger, a method using a control message (C-plane (control plane)) such as an SMS (Short Message Service) or NAS (Non-Access Stratum) message or a data packet (IP packet) is used. Although there are a plurality of methods using a U-plane (user plane), the IWF 210 selects any means based on UE information, network congestion status, and the like.

  The cellular network 200 includes a plurality of entities constituting a 3GPP radio network and a core network, and the MME 220 and the SMS-SC 270 receive a request from the IWF 210 and transmit a C-plane device trigger to the UE 100. have. When the conventional SMS is used as the device trigger, the IWF 210 requests the SMS-SC 270 to transmit a device trigger, and the SMS-SC 270 requests the MME 220 to transmit the SMS. The MME 220 transmits the SMS received from the SMS-SC 270 to the UE 100. For example, the MME 220 transmits SMS to the UE 100 including the SMS in the NAS message container of the Downlink NAS Transport. On the other hand, in the case of the MSC 220, a message dedicated to SMS is transmitted to the UE 100.

  Further, in order to notify the device trigger to the MME 220, the IWF 210 can also transmit the device trigger using an interface connected to the MME 220. In this case, when the MME 220 receives a device trigger (which may be a trigger request) from the IWF 210, the MME 220 converts the device trigger into an SMS format and includes the device trigger in the NAS message container of the Downlink NAS Transport. Alternatively, a trigger of another format may be included in the NAS message and transmitted. On the other hand, the P-GW 230 and the S-GW 240 have a role of transferring the U-plane device trigger generated by the IWF 210 to the UE 100 as a data packet.

  In the following, for simplicity of explanation, the SCS 300 transmits a device trigger transmission request (trigger request) to the IWF 210, and the device trigger based on the trigger request is transmitted to the MME 220 using the means selected by the IWF 210. Will be described by way of an example in which a device trigger is transmitted to the UE 100 using a control message (NAS message) based on the device trigger received from the IWF 210 (or SMS-SC 270). The application server 400 that performs application layer communication with the UE 100 may operate on the SCS 300 or may operate on another node connected to the SCS 300. The SCS 300 transmits a trigger request in response to its own determination or an instruction from the application server 400. Further, the SCS 300 may be disposed in the cellular network 200.

  Upon receiving the device trigger, the UE 100 transmits a control message as necessary, and executes processing such as establishment and change of a connection with the cellular network 200. The control message transmitted at this time includes, for example, a connection request (ATTACH REQUEST), a disconnection request (DETACH REQUEST), a service request (SERVICE REQUEST), a PDN connection establishment request (PDN CONNECTIVITY REQUEST), and a dedicated bearer establishment request (ACTIVATE DEDICATED There are EPS BEARER CONTEXT REQUEST), bearer resource allocation request (BEARER RESOURCE ALLOCATION REQUEST), bearer resource change request (BEARER RESOURCE MODIFICATION REQUEST), etc. For which control message should be sent, the application subject to device trigger And the state of application, the connection status of the UE 100 when a device trigger is received, and the like.

  For example, if the connection (PDN connection, default bearer, dedicated bearer) necessary for the application that received the device trigger to perform data communication is not established (cannot be used), to establish the necessary connection A control message (PDN connection establishment request, dedicated bearer establishment request (bearer establishment request, bearer change request)) is transmitted. Instead of newly establishing a dedicated bearer, an existing bearer may be updated and changed to a bearer that satisfies the application request. When the connection is established, the UE 100 can transmit a data packet (application message) to the SCS 300 via the established connection. The PDN connection is a data communication connection established between the UE 100 and the PGW 230, and is assigned a single IP address used by the UE 100.

  On the other hand, a bearer (also referred to as an EPS bearer) is a connection established in association with the PDN connection, and a GBR (Guaranteed Bit Rate) bearer with a guaranteed bit rate and a best effort Non-GBR bearer. There are types. When a PDN connection is established for a specific APN (Access Point Name, PDN (Packet Data Network) identifier), a default bearer (Non-GBR) is also established at the same time. After the PDN connection and the default bearer are established, the UE 100 establishes an arbitrary dedicated bearer in response to a request such as an application. A bearer in EPS (Evolved Packet System) corresponds to a PDP (Packet Data Protocol) context in UMTS (Universal Mobile Telecommunications System).

  In the first embodiment of the disclosed technology, the application server 400 is assumed as the communication partner of the UE 100, but the communication partner of the UE 100 is not limited to the application server 400, and the SCS 300 is operating. It may be a server or another UE. The cellular network 200 shown in FIG. 1 includes LTE / SAE / EPS (Long Term Evolution / System Architecture Evolution / Evolved Packet System), UMTS, GPRS (General Packet Radio Service), and GSM (Global System for Mobile Communications). In addition to (registered trademark), WiMAX (Worldwide Interoperability for Microwave Access) (registered trademark), mobile WiMAX, WLAN (Wireless Local Access Network), etc. may be used. According to

  FIG. 2 is a sequence diagram illustrating a first example of operations of main entities in the SCS 300 and the cellular network 200 according to the first embodiment of the disclosed technique. The SCS 300 inquires of the DNS 280 about the IP address of the IWF 210 that is the transmission destination of the trigger request (step S2001). If the IP address of the IWF 210 is already held, the inquiry to the DNS 210 is omitted. The SCS 300 transmits a trigger request including the ID of the UE 100 to the IWF 210 (step S2002). The fact that the ID of the UE 100 is included in the trigger request means that the device trigger transmission destination (target) transmitted by the IWF 210 and the MME 220 is the UE 100. Upon receiving the trigger request, the IWF 210 confirms the SCS 300 that is the transmission source of the trigger request (step S2003). The confirmation of the SCS 300 is a check as to whether or not the trigger request received from the SCS 300 may be accepted. For example, whether or not the SCS 300 is authorized to transmit a device trigger. It is confirmed whether the SCS is not restricted in transmission or whether there is a format error in the received trigger request message.

  After confirming that there is no problem in the SCS 300 as the trigger request transmission source, the load control of the trigger request received from the SCS 300 is checked (step S2004). The load control check is a check of the influence on the network bandwidth, the network node, and the contract contents by sending and receiving the trigger request. For example, whether the number of times the trigger request is received from the SCS 300 (Submission Quota) exceeds the specified value. This is confirmation of the load status such as whether the transmission rate (Submission Rate) of the trigger request does not exceed a specified value or whether the processing load of the IWF is overload (Overload). For example, if the transmission frequency of the trigger request received from the SCS 300 exceeds a specified value (such as an upper limit value determined by a contract), it is determined that there is a problem with load control.

  Next, after confirming that there is a problem in the result of the load control check (the transmission frequency exceeds the specified value), the HSS 260 is inquired of the information on the UE 100, and the information on the UE 100 is confirmed (step S2005). Confirmation of UE information is confirmation of whether or not a device trigger can be transmitted to the UE. For example, confirmation of whether or not the status of the response message received from the HSS 260 is normal, or the UE included in the response Confirmation of information (subscription information). For example, as a result of checking the UE information, if the UE is not qualified to receive the device trigger, or if the UE is not in a state in which the device trigger can be received, it is determined that there is a problem with the UE information.

  After confirming that there is no problem (Valid Subscription Information) in the acquired UE information (Step S2007), the IWF 210 sends a trigger response including a value indicating that a device trigger could not be transmitted due to a problem related to load control. (Step S2008). Receiving this trigger response, the SCS 300 retransmits the trigger request at a timing at which no problem occurs in the load control (step S2009). For example, when the back-off timer is included in the trigger response received from the IWF 210, the SCS 300 starts the timer when the trigger response is received, and after the time indicated by the back-off timer has elapsed. Resend the trigger request. A value set in advance may be used as the value of the back-off timer. The IWF 210 that has received the retransmitted trigger request confirms the SCS 300 that is the transmission source (step S2010).

  Next, it is confirmed that there is no problem with the load control (step S2011). Furthermore, the information of UE100 is confirmed (step S2012). In this case, since the IWF 210 holds (caches) the result of the previous query to the HSS 260, the query to the HSS 260 can be omitted by checking the cache (step S2012). If there is no problem in the UE information, a device trigger transmission process is started (step S2013). In step S2008, a value indicating that there is no problem in the UE information may be included together with a value indicating a problem related to load control. Thereby, SCS300 can recognize that the information of UE100 is cached by IWF210.

  FIG. 3 is a sequence diagram illustrating an example of an operation when there is a problem with the result of an inquiry to the HSS 260 in the first embodiment of the disclosed technique. If there is a problem with the result of the inquiry to the HSS 260 (step S3007), a trigger response indicating that the device trigger could not be transmitted due to a problem with the UE information (subscription) is transmitted to the SCS 300 (step S3008). Receiving the trigger response, the SCS 300 does not retransmit the rejected trigger request (step S3009). Thereby, IWF210 can make SCS300 recognize that the trigger request transmission (retransmission) with respect to UE100 cannot be performed. Note that the IWF 210 may transmit a trigger response including a rejection reason indicating both a load control problem and a UE information problem to the SCS 300.

  In this case, the SCS 300 determines that the trigger request for the UE 100 is not retransmitted, and when transmitting a trigger request to be transmitted to the IWF 210 thereafter, it needs to be transmitted at an appropriate timing and frequency that does not cause a problem in load control. It can be recognized that there is a need to switch the destination of the trigger request. For this reason, when transmitting a trigger request to another UE, the SCS 300 transmits the trigger request at an appropriate timing and frequency that does not cause a problem in load control.

  FIG. 15 is a flowchart illustrating an example of processing of the IWF 210 based on the operations described in FIGS. 2 and 3 in the first embodiment of the disclosed technology. When the trigger request is received (step S15001), the SCS 300 of the transmission source is confirmed (step S15002). If there is a problem, the SCS 300 is not permitted to transmit the trigger request, so the trigger can be transmitted. A trigger response including a value indicating the absence is returned to the SCS 300 (step S15003). If there is no problem in the confirmation result of the SCS 300, confirmation of load control related to reception of the trigger request is performed (step S15004).

  If there is no problem in the confirmation of the load control, the UE information is confirmed by inquiring to the HSS 260 (steps S 15006 and S 15008). If there is no problem, the trigger transmission process is started (step S 15011). If there is a problem with the UE information in step S 15008, a trigger response including a value indicating the problem of the UE information is transmitted (step S 15010). On the other hand, if there is a problem in the load control confirmation, the UE information is confirmed by inquiring to the HSS 260 (step S15005). If there is no problem in the UE information, a trigger including a value indicating the load control problem A response is transmitted (step S15009). In step S 15007, if there is a problem with the UE information, a trigger response including a value indicating the problem of the UE information is transmitted (step S 15010).

  FIG. 4 is a sequence diagram illustrating a second example of operations of main entities in the SCS 300 and the cellular network 200 according to the first embodiment of the disclosed technology. The difference from FIG. 2 is that the IWF 210 executes the load control check (step S4007) after confirming the SCS 300 of the transmission source and the information of the UE 100 (steps S4004 and S4005). In FIG. 4, since there was a problem with the load control, a trigger response indicating that the trigger could not be transmitted due to the problem with the load control is transmitted to the SCS 300 (step S4008). Receiving the trigger response, the SCS 300 retransmits the trigger request at a timing at which no problem occurs in the load control (step S4009).

  For example, when the back-off timer is included in the trigger response received from the IWF 210, the SCS 300 starts the timer when the trigger response is received, and after the time indicated by the back-off timer has elapsed. Resend the trigger request. A value set in advance may be used as the value of the back-off timer. The IWF 210 that has received the retransmitted trigger request confirms the SCS 300 of the transmission source (step S4010). Next, as for the confirmation of the information of the UE 100, since the result of the inquiry to the HSS 260 performed previously is held (cached), the inquiry to the HSS 260 can be omitted by confirming the cache (step) S4011). After confirming that there is no problem in the information of the UE 100, it is confirmed that there is no problem in the load control (step S4012), and a device trigger transmission process is started (step S4013).

  FIG. 5 is a sequence diagram illustrating an example of an operation in the case where the UE information is confirmed after the trigger request transmission source is confirmed in the first embodiment of the disclosed technology. Similarly to FIG. 4, after confirming the SCS 300 of the transmission source, an inquiry is made to the HSS 260 (steps S5004 and S5005). If there is a problem with the UE information (step S5006), a trigger response indicating that the trigger could not be transmitted due to a problem with the UE information without checking the load control is transmitted to the SCS 300 (step S5007).

  On the other hand, FIG. 6 is a sequence diagram illustrating an example of an operation when the load control is confirmed even when there is a problem with the UE information in the first embodiment of the present disclosure. Even if there is a problem with the UE information (step S6006), the IWF 210 checks the load control (step S6007). If there is a problem with the load control (step S6007), the problem with the UE information and the problem with the load control A trigger response indicating both of these is transmitted to the SCS 300.

  FIG. 7 is a flowchart illustrating an example of processing of the IWF 210 based on the operations described in FIGS. 4, 5, and 6 in the first embodiment of the disclosed technique. The IWF 210 that has received the trigger request (step S7001) checks whether or not the SCS 300 that is the transmission source of the trigger request is an SCS that is permitted to transmit the trigger (step S7002). An inquiry is made to the HSS 260 (step S7004). If there is no problem in the UE information, load control is checked (step S7006), and if there is no problem, trigger transmission processing is started (step S7007). On the other hand, if there is a problem with the load control check, a trigger response indicating that the trigger could not be transmitted is transmitted (step S7008). If there is a problem with the UE information, a trigger response indicating that the trigger could not be transmitted due to a problem with the UE information is transmitted (step S7009).

  Next, a configuration example of the IWF 210 in the first embodiment of the disclosed technology will be described. FIG. 8 is a block diagram illustrating an example of the configuration of the IWF 210 according to the first embodiment of the disclosed technology. 8 includes an interface 101, a UE information confirmation unit 102, a trigger request processing unit 103, a load control determination unit 104, a transmission source confirmation unit 105, a device trigger transmission processing unit 106, and a trigger response transmission processing unit 107. have.

  The interface 101 has a function for the UE 100 to connect to the network and transmit / receive a message (or packet). The interface 101 also includes hardware that modulates and demodulates information into an electrical signal in order to communicate with other communication devices (for example, a network node or other UE 100 arranged on the network). . The UE information inquiry unit 102 receives an instruction from the trigger request reception processing unit 103 and acquires information on the UE 100 that is the destination of the trigger request from the HSS 260. For the received trigger request, the trigger request reception processing unit 103 instructs the transmission source confirmation unit 105 to confirm whether or not the SCS 300 that is the transmission source is an SCS that is permitted (Authorized) to transmit the trigger request. .

  If there is no problem in the result of the transmission source confirmation unit 105, the load control determination unit 104 is instructed to confirm the load control. Furthermore, the trigger request reception processing unit 103 instructs the UE information confirmation unit 102 to confirm information regarding the UE 100 that is the destination of the device trigger. When there is no problem in the information of the UE 100 and there is no problem in the determination result of the load control determination unit 104, the trigger request reception processing unit 103 instructs the device trigger transmission processing unit 106 to transmit a device trigger. To do. On the other hand, if there is no problem in the information of the UE 100, but there is a problem in the load control, the trigger response transmission processing unit 107 is instructed to notify the SCS that the device trigger cannot be transmitted.

  The device trigger transmission processing unit 106 selects a device trigger transmission method and starts processing for transmitting a device trigger using the selected transmission method. When SMS (T4 interface) is selected as the transmission method, the ID of the UE 100 is notified to the SM-SC 270 to request transmission of SMS. Further, when the direct request (T5 interface) to the MME 220 is selected, the ID of the UE 100 is notified to the MME 220, and the transmission of the device trigger using the NAS message is requested.

  As described above, according to the first embodiment of the disclosed technology, the IWF 210 confirms that there is a problem in the load control and confirms that there is a problem in the information of the UE 100 that is the target of the trigger request. Therefore, it is possible to prevent retransmission of a trigger request for requesting transmission of a device trigger to the UE 100 having a problem with UE information. Thereby, the number of signalings transmitted / received between the SCS 300 and the IWF 210, the network load, and the processing load and power consumption associated therewith can be reduced.

(Second Embodiment)
Next, a trigger request transmission method by the SCS 300 when a trigger response is received from the IWF 210 in the second embodiment of the disclosed technology will be described. In the second embodiment of the disclosed technology, it is assumed that the SCS 300 also holds (or can acquire at an arbitrary timing) an IP address of an IWF 290 different from the IWF 210 that transmitted the trigger request. As described in the first embodiment of the disclosed technology, the IWF 210 that has received the trigger request from the SCS 300 confirms that there is no problem in the information of the UE 100 that is the device trigger transmission destination, and then performs load control. A trigger response indicating that the device trigger could not be transmitted due to a problem is notified to the SCS 300. Upon receiving this trigger response, the SCS 300 retransmits the trigger request to the IWF 210 at a timing at which no problem occurs in the load control. The IWF 210 that has received the retransmitted trigger request caches the result of the inquiry made to the HSS when the first trigger request is received. Therefore, the inquiry to the HSS can be omitted by checking the cache.

  FIG. 9 is a sequence diagram illustrating an example of operations of main entities in the SCS 300 and the network 200 according to the second embodiment of the disclosed technology. The UE 100 holds IP addresses of two IWFs (IWF 210 and IWF 290) (Step S9003) by pre-configuration information and an inquiry to the DNS server (Steps S9001 and S9002). Note that the number of IP addresses held is not limited to two.

  When receiving a trigger response indicating that the device trigger could not be transmitted due to a problem in load control as a response to the trigger request transmitted from the UE 100 to the IWF 210 (step S9009), a trigger request is sent to another IWF 290. Re-send (step S9010). That is, when the transmitted trigger request is rejected, the SCS 300 switches the trigger request transmission destination from the IWF 210 to the IWF 290. The IWF 290 receives the trigger request from the SCS 300, confirms the SCS 300 of the transmission source (step S9011), confirms the load control (step S9012), and confirms the UE information (steps S9013 and S9014). If there is no (step S9015), the device trigger transmission process is started (step S9016).

  FIG. 10 is a sequence diagram illustrating a first example when the SCS 300 according to the second embodiment of the present disclosure transmits a trigger request to the UE 100 and the UE 101, respectively. The IWF 210 that has received the trigger request including the ID of the UE 100 (step S10004) performs confirmation of the SCS 300, confirmation of load control (step S10005), confirmation of UE information (steps S10006 and S10007), and there is a problem with load control. If it does, a trigger response indicating that is returned (step S10008). The SCS 300 that has received the trigger response retransmits the trigger request including the ID of the UE 100 to another IWF 210 (step S10009).

  Further, the SCS 300 also transmits a trigger request including the ID of the UE 101 that has not been transmitted to the IWF 210. That is, when the transmitted trigger request is rejected, the SCS 300 switches the transmission destination of both the rejected trigger request and the trigger request that has not been transmitted from the IWF 210 to the IWF 290. The IWF 290 receives the retransmitted trigger request including the ID of the UE 100 from the SCS 300 (step S10009) and the untransmitted trigger request including the ID of the UE 101 (step S10015), and confirms the SCS 300 and confirms the load control (step S10015). S10010, S10016) and HSS inquiry (steps S10011, S10012, S10017, S10018) are performed, and if there is no problem in their confirmation (step S10019), device trigger transmission processing is started (step S10020).

  FIG. 11 is a sequence diagram when the SCS 300 according to the second embodiment of the present disclosure transmits a trigger request to the UE 100. When the SCS 300 receives a trigger response indicating a load control problem (step S11008), it holds the IP address of another IWF 290, but resends the trigger request to the IWF 210 without switching to the IWF 290 (step S11009). By switching the transmission destination of the retransmission trigger request to the IWF 290, it may be possible to immediately transmit the trigger request without being subjected to load control restrictions such as those generated in the IWF 210. However, even if the SCS 300 recognizes the presence (IP address or ID) of the IWF 290, it selects the IWF 210 as the retransmission destination of the trigger request.

  Thereby, since the IWF 210 already holds the information of the UE 100, the signaling for acquiring the information of the UE 100 from the HSS 260 can be omitted (step S11011). Note that the SCS 300 preferably recognizes that a trigger response indicating a load control problem has been transmitted after the UE information is confirmed in the IWF 210. In this case, the SCS 300 determines that it is necessary to select the IWF 210 instead of the IWF 290 as a retransmission destination of the trigger request in order to omit the UE information inquiry to the HSS 260 because the information of the UE 100 is cached in the IWF 210. . Thereby, the processing load of HSS260 and the load given to a network band can be reduced. In addition, when the value indicating that there is no problem in the UE information is included in the trigger response in step S11008, the SCS 300 can recognize that the information of the UE 100 is cached in the IWF 210. It can be determined that the IWF 210 is appropriate as a retransmission destination of the trigger request.

  FIG. 12 is a sequence diagram illustrating a second example when the SCS 300 according to the second embodiment of the present disclosure transmits a trigger request to the UE 100 and the UE 101, respectively. When the SCS 300 receives a trigger response indicating a load control problem (step S12008), the SCS 300 transmits a trigger request including the ID of the UE 100 to the IWF 210, and a trigger request including an ID of the UE 101 different from the UE 100 (untransmitted trigger request). Is transmitted to the IWF 290. That is, when the transmitted trigger request is rejected, the SCS 300 switches the transmission destination of the untransmitted trigger request from the IWF 210 to the IWF 290 without switching the retransmission destination of the rejected trigger request.

  Since the SCS 300 has received a trigger response indicating a load control problem from the IWF 210, switching to another IWF 290 can transmit the trigger request without being restricted by the load control. As shown in FIG. 10, when the retransmission destination of the trigger request for the UE 100 and the transmission destination of the trigger request for the UE 101 different from the UE 100 are switched to the IWF 290, the IWF 290 needs to inquire the HSS 260 for information on both the UE 100 and the UE 101. . On the other hand, as shown in FIG. 11, since the IWF 210 already holds the information of the UE 100, by sending a trigger request including the ID of the UE 100 to the IWF 100, transmission and reception of signaling for inquiring the UE 1 information to the HSS 260. Can be made unnecessary. Therefore, when transmitting a trigger request to a plurality of UEs, the SCS 300 determines that a rejected trigger request should be retransmitted to the same IWF 210, and a trigger request not yet transmitted should be transmitted to another IWF 290. To do.

  As a result, the load on the network due to the retransmission trigger request is reduced, and an untransmitted trigger request can be transmitted without being restricted by load control. Note that the SCS 300 may transmit a trigger request for the UE 101 to the IWF 210. In this case, as in the case of transmission to the IWF 290, since the IWF 210 does not hold the information of the UE 101, it is necessary to make an inquiry to the HSS 260. Therefore, both loads associated with the inquiry to the HSS 260 are the same.

  Next, a configuration example of the SCS 300 in the second embodiment of the disclosed technology will be described. FIG. 13 is a block diagram illustrating an example of the configuration of the SCS 300 according to the second embodiment of the present disclosure. The UE 100 illustrated in FIG. 13 includes an interface 101, a DNS processing unit 202, a trigger request transmission unit 203, a trigger response reception unit 204, and an application 205.

  The interface 201 has a function for the SCS 300 to connect to the network and transmit / receive a message (or packet). The interface 201 also includes hardware that modulates and demodulates information into an electrical signal in order to communicate with other communication devices (for example, other network nodes or UEs 100 arranged on the network). .

  The DNS processing unit 202 transmits a query to the DNS server 280 to acquire the IP address of the IWF 210 that is the destination of the trigger request, receives a response including the IP address of the IWF 210 (and the IWF 290), and sets the IP address. Hold. The query is transmitted including the ID of the IWF 210 or the ID of the trigger target UE (consisting of a domain ID and a local ID). The trigger request transmission unit 203 receives a request from the application 205 and transmits a trigger request for requesting the UE 100 to transmit a device trigger to the IWF 210.

  Also, when receiving a notification from the trigger response receiving unit 204 that a trigger response indicating a load control problem has been received, the IWF 210 is selected as the retransmission destination of the transmitted trigger request, and the transmission destination of the untransmitted trigger request is selected. Select IWF 290 and send each trigger request. The trigger response reception unit 204 receives a trigger response to the trigger request transmitted by the trigger request transmission unit 203. If the received trigger response includes a value (Cause) indicating failure due to load control, the trigger request transmission unit 203 is instructed to retransmit the trigger request. The application 205 requests the trigger request transmission unit 230 to transmit a device trigger to the UE 100.

  FIG. 14 is a flowchart illustrating processing of the SCS 300 when the SCS 300 according to the second embodiment of the present disclosure receives a trigger response indicating a problem due to load control. When a trigger response is received (step S14001), the rejected trigger request is retransmitted to the same IWF at an appropriate timing so as not to cause a load control problem (step S14002). Then, it is determined whether or not there is an untransmitted trigger request (step S14003). If there is an untransmitted trigger request, it is transmitted to another IWF (step S14004). If there is no unsent trigger request, the reception of a trigger response is awaited (step S14005).

  As described above, according to the second embodiment of the disclosed technology, when the trigger request is rejected due to a problem related to load control, the SCS 300 retransmits the already transmitted trigger request to the same IWF again, Trigger requests that have not yet been sent can be sent to another IWF. As a result, it is possible to eliminate the process of inquiring of the HSS for acquiring the information of the UE that is the transmission destination of the device trigger. Therefore, the number of signaling transmitted and received between the HSS 260 and the IWF 290, the network load, and the process associated therewith Load and power consumption can be reduced.

  Further, in one aspect of the disclosed technology, the trigger response transmission unit is confirmed that there is a problem in the load control by the load control confirmation unit, and the UE information confirmation unit has no problem in the UE information. When confirmed, a trigger response indicating that there is a problem with the load control may be transmitted to the server.

  In one aspect of the disclosed technology, the load control may be either a processing load of the network node or a reception frequency of the trigger request.

  One aspect of the disclosed technique is a trigger request for requesting a network node to transmit a device trigger instructing a communication terminal to start an operation, and the trigger request is transmitted from a plurality of network nodes. A trigger destination determination unit for selecting a network node as a transmission destination; a trigger request transmission unit for transmitting the trigger request to the selected network node; and a trigger for receiving a trigger response to the trigger request transmitted to the network node A server that re-selects the network node as a retransmission destination of the trigger request when the trigger response indicates that there is a problem with the load control. Can be included. With the above-described configuration, for example, an effect that the switching of the gateway can be executed for the connection used for data communication is realized.

  In one aspect of the disclosed technology, the trigger destination determination unit indicates that the trigger response has a problem in the load control as a transmission destination of a trigger request to a communication terminal different from the communication terminal. In this case, a network node different from the network node may be selected.

  For example, the aspects of the present disclosure can be combined as appropriate. Further, one aspect of the disclosed technology is realized by a method realized by a user terminal or the like in addition to a network node and a server, a program for causing a computer to execute the method, a recording medium storing the program, and the like. May be.

  In addition, each functional block used in the description of the above embodiment may be realized by hardware, software, or a combination thereof. For example, the functional blocks included in each device shown in the block diagram or the like, or each processing unit having an equivalent function is realized by hardware such as various computer CPUs, memories, and various interfaces including communication interfaces. May be. Further, each functional block and each processing unit may be realized by causing a computer to execute a program in which operations related to each function are described. The flowcharts and sequence charts in the above embodiments may be realized by hardware such as a CPU and a memory.

  Note that each function block used in the description of each of the above embodiments, each step in the flowchart, and each process in the sequence chart may be typically realized as an LSI that is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used. Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. For example, biotechnology can be applied.

  The disclosed technique has an effect that unnecessary retransmission of a trigger request can be prevented, and further, a process of querying UE information to the HSS can be omitted, and a communication technique using a cellular communication function (particularly, M2M communication). This technology can be applied.

100, 101 UE (communication terminal)
101, 201 Interface 102 UE information confirmation unit 103, trigger request reception processing unit 104 load control determination unit 105 transmission source confirmation unit 106 device trigger transmission processing unit 107 trigger response transmission processing unit 200 cellular network (network)
202 DNS processing unit 203 Trigger request transmission unit 204 Trigger response reception unit 205 Application 210, 290 IWF
220 MME / SGSN / MSC (MME)
230 P-GW / GGSN / ePDG (P-GW)
240 S-GW
250 eNB / NB / BS
260 HSS / HLR
270 SMS-SC / GMSC / IWMSC
280 DNS
300 SCS (server)
400 Application server (application)

Claims (5)

A network node that transmits a device trigger that instructs a communication terminal to start operation,
A trigger request receiving unit that receives from the server a trigger request for transmitting the device trigger to the communication terminal;
A UE information confirmation unit for confirming whether the device trigger can be transmitted to the communication terminal;
A load control confirmation unit for confirming whether there is a problem with the load control, and
A trigger response transmitter for transmitting a trigger response to the server after the confirmation of the UE information by the UE information confirmation unit and the confirmation of the load control by the load control confirmation unit;
Have network nodes. The trigger response transmission unit confirms that there is a problem with the load control by the load control confirmation unit, and confirms that there is no problem with the UE information by the UE information confirmation unit. The network node according to claim 1, wherein a trigger response indicating that there is a message is transmitted to the server. The network node according to claim 1, wherein the load control is either a processing load of the network node or a reception frequency of the trigger request. A trigger request for requesting a network node to transmit a device trigger for instructing the communication terminal to start an operation, and a trigger for selecting a network node as a transmission destination of the trigger request from a plurality of network nodes A destination determination section;
A trigger request transmitter for transmitting the trigger request to the selected network node;
A trigger response receiver for receiving a trigger response to the trigger request transmitted to the network node;
The server that re-selects the network node as a retransmission destination of the trigger request when the trigger response indicates that there is a problem with the load control. The trigger destination determination unit is a network different from the network node when the trigger response indicates that there is a problem in the load control as a transmission destination of a trigger request to a communication terminal different from the communication terminal. The server according to claim 4, wherein a node is selected.