KR20130142895A - An overload control method and apparatus for device triggering in mobile communication networks - Google Patents

Abstract

The present invention relates to a method for controlling overload due to network congestion in performing an MTC device triggering procedure in a 3GPP mobile communication network.

Description

An Overload Control Method and Apparatus for Device Triggering in Mobile Communication Networks}

The present invention relates to a method and apparatus for controlling overload due to network congestion in performing an MTC device triggering procedure in a 3GPP mobile communication network.

Machine type communication (MTC) is a form of data communication that represents machine to machine communication where one or more entities do not necessarily require human interaction.

MTC communication is likely to communicate with multiple terminals at the same time. For example, when triggering a terminal in a network, the network may simultaneously transmit a triggering message to a plurality of MTC terminals, and an application of the MTC terminal receiving the triggering message may perform a specific action to simultaneously communicate with the network. . This MTC communication has a problem that can increase the overload of the network.

The present invention devised to solve the above problems is to overload the network entity in the T4 interface between the MTC-IWF and the SMS-SC server and the associated mobile communication network in performing device triggering in a mobile land network (PLMN) It is an object to provide a method of controlling.

An embodiment of the present invention provides an entity performing a mobility management function in a network, comprising: a receiver configured to receive a short message for device triggering or a paging message for device triggering from an entity delivering a short message or a mobile telephone switch; A controller for determining whether an overload condition is caused by network congestion; And a transmitter for transmitting the short message or the transmitter for transmitting the message indicating the overload to the mobile telephone exchange when it is determined that the overload is determined.

Another embodiment of the present invention, a transmission unit for transmitting a paging message for device triggering to the mobility management entity; A receiving unit for receiving a message indicating an overload from the mobility management entity; And a controller for reducing traffic of a paging message for device triggering upon receiving a message comprising a traffic reduction indication from the mobility management entity.

Another embodiment of the present invention is a device triggering overload control method executed in an entity performing a mobility management function in a network, the method comprising: for short message or device triggering for device triggering from an entity carrying a short message or from a mobile telephone exchange. Receiving a paging message; Determining whether an overload condition is caused by network congestion; And when it is determined that the overload is determined, transmitting a message indicating the overload to the entity that delivers the short message or the mobile telephone exchange.

Another embodiment of the present invention provides a device triggering overload control method executed in a mobile telephone switch, comprising: transmitting a paging message for device triggering to a mobility management entity; Receiving a message indicating an overload from the mobility management entity; And when receiving a message including a traffic reduction indication from the mobility management entity, reducing the traffic of the paging message for device triggering.

As described above, the present invention enables the overload control of the MME / SGSN to be applied to the device triggered incoming SMS through the SMS-SC, so that the overload of the MME / SGSN may be worsened due to the trigger load by the T4 triggering. The problem can be avoided and the possibility of exacerbating the MME / SGSN overload can be prevented by the MTC device performing application specific actions in response to a device trigger on the MTC device to initiate communication with the SCS server or application server. It has an effect.

1 shows a 3GPP communication network structure for MTC communication.
2 illustrates a device triggering procedure via Tsp.
3 illustrates a T4 trigger delivery flow in accordance with the present invention.
4 illustrates a mobile incoming SMS service procedure in a 3GPP system.
5 illustrates a device triggering procedure via a Tsp according to an embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

3GPP (3rd Generation Partnership Project) structure for Machine Type Communication (MTC) is shown in FIG. 1.

End-to-end communication between an MTC application in a mobile communication terminal (UE) and an MTC application in an application server (AS) of an external network of a mobile communication network is performed by a 3GPP system and a service capability server (SCS) Server). In FIG. 1, a direct model represents a model in which an AS directly connects to an operator network without using an SCS to perform user plane communication with a UE.

The Indirect Model represents a model in which the AS indirectly connects to the operator's network through the services of the SCS to perform indirect user-plane communications with the UE or to use additional services such as device triggering.

The Hybrid Model shows the use of direct and indirect models between AS and UE simultaneously.

Configuration List

    UE (User Equipment): a mobile communication terminal, the UE can host one or more MTC applications

   - RAN (Radio Access Network): A radio access network

   - MSC (Mobile Switching Center): Circuit switching based mobile switching center

   - Serving GPRS Support Node (SGSN): A packet-based mobile switching center performing mobility management

   - Gateway GPRS Support Node (GGSN): An entity providing interworking between the GPRS network and an external packet-switched network

   - MME (Mobility Management Entity): An object on the control plane for supporting the mobility management function within the Evolved Packet System (EPS)

   - S-GW (Serving Gateway): Gateway that terminates the interface to E-UTRAN

   - P-GW (PDN Gateway): Gateway that terminates the interface to PDN

   Service Capability Server (SCS): An entity that is connected to a 3GPP network to communicate with UEs used for MTC and is a Home Public Land Mobile Network (HPLMN) for device triggering. Connected with MTC-IWF or SMS-SC on. SCS can be used by one or more MTC applications.

  - SMS-SC (Short Message Service-Service Center): An entity that performs a function of relaying, storing, and delivering a short message between objects (UE)

  Home Subscriber Server (HSS): A master database of subscribers, an object containing subscription-related information needed to support session processing on network objects.

  Machine Type Communication-InterWorking Function (MTC-IWF): A function that relays or translates a signaling protocol used to operate a specific function in a mobile communication network through a Tsp interface with an SCS server. Object to perform

  - Tsp: Reference point for control plane signaling between SCS and MTC IWF

  -T4: reference point between SMS-SC and MTC IWF in home mobile communication network

  - T5a: The reference point between the MTC-IWF and the serving SGSN.

  - T5b: reference point between MTC-IWF and serving MME

  - T5c: reference point between MTC-IWF and serving MSC

  S6m: reference point between MTC-IWF and HSS / HLR

MTC devices (UEs used for MTC or M2M device or UE) periodically transmits and receives data with the MTC application server or SCS server through the mobile communication network. The MTC user may allow the MTC device to periodically initiate data communication via the mobile communication network to transmit data to the MTC application server or the SCS server. However, the MTC application server or SCS server communicates with the MTC application server or SCS server through the mobile network for controlling and managing the MTC device and collecting data on demand. You can also do that. As in the latter case, the SCS server transmits trigger information to the MTC device through the mobile communication network so that the MTC device triggers a specific action of the application. Specific actions of the application include that the MTC device initiates communication with the SCS server, such as the indirect model, or that the MTC device initiates communication with the application server, such as a mixed model. Device triggering is necessary when the IP address for the MTC device is not available or not reachable by the SCS server / application server.

Device triggering for large numbers of MTC devices can cause network congestion. Thus, the MTC-IWF, which handles device triggering, provides a load control function on the device trigger procedure.

2 illustrates a device triggering procedure via Tsp.

Referring to FIG. 2, in step 1, the SCS server inquires the address of the MTC-IWF to a DNS (Domain Name System) server. In step 2 the SCS server sends a device triggering request message to the MTC-IWF. In step 3, the MTC-IWF performs authentication and load control of the SCS server.

. In steps 4 and 5 the MTC-IWF queries the HSS for subscriber information. In step 6a, the MTC-IWF selects a trigger message delivery method. If T5 triggering is selected to deliver the trigger message via the T5a / T5b / T5c interface, then the T5 device trigger delivery procedure is performed in step A. If T5 triggering failed or T4 triggering is selected in step 6b, then in step B a T4 device trigger transfer procedure using SMS is performed. In step 7, the MTC-IWF sends a device trigger report to the SCS server. In operation 8, the action is performed in response to the device trigger.

 Load control on the device triggering procedure is described in step 3.

Receiving the trigger request message in step 3, the MTC-IWF checks if the SCS is authorized to send a trigger request and if the SCS has exceeded the quota or rate of trigger submission via the Tsp. If this check fails, the flow ends at this step and the MTC-IWF sends a Device Trigger Confirm message with a cause value indicating the cause for the failure condition.

As alternatives to load control in the MTC device trigger procedure, there are overload control method in Tsp interface between MTC-IWF and SCS server and overload control method in T5 interface between MTC-IWF and MME / SGSN. .

The overload control method in the Tsp interface is a suppression factor, suppression delay / period or suppression subcategory (eg application identifier, priority) in order to suppress the trigger load that the MTC-IWF is sent from one or more SCS servers to the SCS server. When a message including optional information elements indicating a rank type is transmitted through the Tsp interface, the SCS server controls the traffic load of the trigger request according to the received message and the MTC subscription policy. .

The overload control method in the T5 interface is a method in which the MME / SGSN invokes the overload control procedure by the MTC-IWF via the T5 interface. The MME / SGSN triggers the transmission from the MTC-IWF. In order to suppress the load, a message containing optional information elements indicating a suppression factor, a suppression delay / duration or a suppression subcategory (eg application identifier, priority type) may be sent to the T5 interface. Through the MTC-IWF and control the trigger load according to the received message.

As described above, the overload control for device triggering in the existing mobile communication network includes message checking including quota suppression of MTC-IWF, trigger suppression information due to overload occurrence through Tsp interface between MTC-IWF and SCS server, and MME / Through the T5 interface between the SGSN and the MTC-IWF, the message delivery method including the trigger suppression information due to the overload occurred. In other words, there is no overload control function for triggering caused by T4 triggering. The short message delivered by the store & forward method did not need to take into account network congestion. In particular, in the case of a general short message that does not cause data communication, there was no need to associate with a non-access-stratum (NAS) level congestion control. Therefore, the trigger request that successfully checks the MTC-IWF quota could perform device triggering through the T4 interface, and the incoming SMS delivery by T4 triggering (device triggering via SMS-SC) is not limited to the overload control of the MME / SGSN. Since it can be transmitted without limitation by NAS level Mobility Management Congestion Control or APN based Congestion Control, there is a problem that the overload of MME / SGSN may be worsened by the trigger load by T4 triggering. In particular, when device triggering is delivered to the MTC device, there is a problem that the MTC device may increase the network overload by performing communication with the SCS server or the application server by performing a specific action of the application.

3 illustrates a T4 trigger delivery flow according to an embodiment of the invention. This will be described below with reference to FIG.

1) MTC-IWF selects the appropriate SMS-SC based on the configured information. The MTC-IWF sends a Submit Trigger message to the SMS-SC. The submission trigger message includes MTC device's identifier information (external identifier or MSISDN), IMSI, SCS identifier, trigger reference number, validity period, priority, serving node ID (s), SMS Application port ID, trigger payload It includes. The SMS-SC avoids additional HSS interrogation (SRI for SM) and receives the necessary parameters in the submission trigger message from the MTC-IWF. The SMS Application port ID is set to address the triggering function in the UE.

And / or, the SMS-SC may detect the trigger signaling load associated with a specific MTC-IWF, a specific SMS application port ID, etc. by utilizing the information in the Submit Trigger message. The SMS-SC can perform load control based on the following criteria.

Trigger in rate from a particular MTC-IWF or a specific SCS server, or

Aggregate ingress rates from all MTC-IWF or all SCS servers, or

The maximum number of queuing trigger requests from a particular MTC-IWF or all MTC-IWF or a particular SCS server or all SCS servers for further processing, or

One or more MME (s) / SGSN (s) / MSC (s) notified of congestion by SMS-SC, or

Received from MME / SGSN / MSC for Forward Short Message from SMS-SC to MTC device including the cause of failure due to congestion of MME / SGSN / MSC in delivery report message, or

Setting in network management.

And / or, the SMS-SC and MTC-IWF may support a function for providing load control through the T4 interface in the following manner.

SMS-SC provides optional information indicating suppression factor, suppression delay / period or suppression subcategory (eg priority type, SCS server identifier, etc.) via the T4 interface to reduce trigger load. Rules / instructions can be provided to the MTC-IWF by sending appropriate messages that include Optional Information Elements.

 And / or, the SMS-SC may report to the MTC-IWF the success of the trigger or the failure of the trigger due to network congestion.

 And / or, the MTC-IWF may perform load control in accordance with the rules of the MTC subscription to control the traffic load of rules / directives received from the SMS-SC and / or trigger request.

2) The SMS-SC sends a Submit Trigger Confirm message to the MTC-IWF to confirm that the SMS submission has been accepted by the SMS-SC.

And / or, when the SMS-SC detects a trigger signaling overload, the SMS-SC may submit a cause value to indicate that the trigger failed due to network congestion, and / or submit a backoff timer. (Or a submit trigger Reject message).

3) The MTC-IWF sends a Device Trigger Confirm message to the SCS to confirm that the device trigger request has been accepted for delivery to the UE.

And / or, if received from SMS-SC a cause value for indicating that the trigger failed due to network congestion, and / or a Submit Trigger Confirm message (or a submit trigger Reject message) including a backoff timer, The IWF sends a Device Trigger Confirm message to the SCS, including a cause value indicating the cause for the failure condition, and the flow may end at this step.

And / or, the MTC-IWF may prevent the Submit Trigger message from being transmitted to the corresponding SMS-SC until the backoff timer received from the SMS-SC expires. Or Submit with a trigger reference number equal to the trigger reference number included in the Submit Trigger message (eg received Submit Trigger Confirm message previously sent), including the normal priority value, until the backoff timer expires. It is possible to prevent the Device Trigger Request message from being transmitted by including the same or lower priority value as the priority value included in the Trigger message).

And / or if the MTC-IWF receiving the backoff timer sends a Submit Trigger message before the backoff timer expires, the SMS-SC saves the backoff timer and immediately rejects the subsequent Submit Trigger, or In addition, the MTC-IWF may transmit a Submit Trigger message before the backoff timer expires to include a cause value indicating that the trigger has failed in the Submit Trigger Confirm message.

And / or, the MTC-IWF receiving the backoff timer contains a normal priority value before the backoff timer expires, or is equal to the priority value included in a previously sent Submit Trigger message, or When sending a Submit Trigger message with a lower priority value, SMS-SC saves the backoff timer and immediately rejects subsequent Submit Triggers, or MTC-IWF submits a Submit Trigger before the backoff timer expires. A cause value indicating that a trigger failed by sending a message can be included in the Submit Trigger Confirm message.

And / or, even when the MTC-IWF receives a Submit Trigger Confirm message including a cause value indicating a cause for a failure condition, the MTC-IWF transmits a Submit Trigger message including a high priority value. Can be.

And / or, the MTC-IWF may include a backoff timer or a self-generated backoff timer received from the SMS-SC in the device trigger confirmation message transmitted to the SCS.

And / or, the SCS receiving the backoff timer may prevent the device trigger request message from being transmitted until the backoff timer expires. Or a normal reference value until the backoff timer expires, or has a trigger reference number equal to the trigger reference number included in a previously sent Device Trigger Request message (eg, a received device trigger confirmation message). The device trigger request message may be prevented from including a priority value equal to or lower than the priority value included in the device trigger request message).

And / or when the SCS receiving the backoff timer sends a Device Trigger Request message before the backoff timer expires, the MTC-IWF sends a Device Trigger Request message before the backoff timer expires to indicate that the trigger has failed. The cause value can be included in the Device Trigger Confirm message and transmitted.

And / or the SCS receiving the backoff timer includes a normal priority value before the backoff timer expires, or is equal to or lower than the priority value included in a previously sent Device Trigger Request message. When sending a Device Trigger Request message with a rank value, the MTC-IWF saves the backoff timer and immediately rejects any subsequent Device Trigger Request, or the SCS rejects the Device Trigger Request message before the backoff timer expires. The cause value indicating that the trigger failed by sending can be included in the Device Trigger Confirm message.

And / or, the SCS includes a high priority even when receiving a Device Trigger Confirm message including a cause value indicating the cause of the failure condition due to network congestion. (eg, for an emergency bearer service or a high priority service), a Device Trigger Request message may be transmitted.

And / or, when the SCS receives a Device Trigger Confirm message that includes a cause value indicating the cause of the failure condition due to network congestion, the SCS receives a high priority value ( A message may be sent or a message sent may be allowed only in a pre-allocation limit capable of sending a Device Trigger Request message, including a high priority.

And / or, the back off timer may be stored per MTC device.

And / or, the backoff timer may be stored for each network entity (e.g. MTC-IWF, SCS).

And / or to avoid sending / initiating a (nearly) deferred Device Trigger Request message to a large number of MTC devices, the MTC-IWF may set a backoff timer value to prevent the deferred request from being synchronized. You can choose.

And / or to avoid sending / initiating a (nearly) deferred Submit Trigger message to a large number of MTC devices, the SMS-SC may select a backoff timer value such that the deferred request is not synchronized.

4,5,6) A short message is delivered to the UE. This may include delivery attempts within the MSC, SGSN and / or MME. This may include delivery attempts through an IP-Multimedia Subsystem (IMS).

And / or, if the MME / SGSN performs General NAS level Mobility Management Congestion Control (APN) or Access Point Name (APN) based congestion control, the MME / SGSN is used to reduce the amount of suppression to reduce the trigger load. an appropriate message including an optional information element indicating a suppression factor, suppression delay / duration or suppression subcategory (eg priority type, SCS server identifier, congestion APN, etc.) By sending to the SMS-GMSC (SMS Gateway MSC), you can activate overload control for trigger load from the SMS-SC or SMS-GMSC.

And / or, if the MME / SGSN stores a T4 trigger request (short message) for the target MTC device, the MME / SGSN stops trigger request forwarding to the MTC device and resumes trigger request forwarding when network congestion is resolved. can do.

And / or, during an overload situation, the MSC / MME / SGSN and SMS-SC may maintain support for MTC device triggering for an emergency bearer service or a high priority service. have.

And / or, when the MME / SGSN recovers from network congestion, the MME / SGSN sends an appropriate message to the SMS-SC or SMS-GMSC, including optional null information about the suppression trigger, or allows more trigger traffic to be carried. By sending an appropriate message with optional null information, the SMS-SC or SMS-GMSC can resume trigger processing when the suppression delay expires.

 And / or, if the MME / SGSN is configured to do overload restriction in the MME / SGSN to avoid an overload situation, if the MME / SGSN is SMS-GMSC or SMS-SC and And / or limit the load that the MSC generates. This may be because the MME / SGSN sends an appropriate message indicating the overload to the SMS-GMSC via the SGd interface (interface between the MME and SMS-GMSC), or the SMS-SC and / or SGs interface (interface between the MME and MSC) / This can be achieved by sending an appropriate message indicating overload to the MSC via the Gs interface (the interface between the SGSN and the MSC). The message optionally includes a Traffic Load Reduction Indication, and depending on the requested percentage, the SMS-GMSC or SMS-SC or MSC may reduce device triggered traffic. SMS-GSMS or SMS-SC or MSC can select and reduce short message forwarding traffic for device triggering.

And / or, it may be considered to transfer the incoming SMS using the mobile incoming SMS delivery method through the SGs interface.

4 illustrates a procedure for delivering an incoming SMS using the mobile incoming SMS delivery scheme through the SGs interface.

Referring to FIG. 4, in step 1 the combined EPS / IMSI attach procedure is performed. In step 2-4 the SC (SMS-SC) starts the transmission of the mobile incoming SMS. In step 5 the MSC / VLR (Visitors Location Register) sends a paging message to the MME. In step 6, the MME starts a paging procedure for transmitting a paging message to each base station of a cell belonging to the tracking area where the MS / UE is registered. In step 7, the base station performs paging to MS / UE. In step 8, the UE sends a service request message to the MME. In step 8a, the MME sends a service request message to the MSC. In step 9a, the SMS message is forwarded to the MME. In step 9b the MME encapsulates the SMS message into a NAS message and sends the message to the MS / UE. In steps 9c and 9d, the MS / UE informs the MSC / VLR of the receipt of the SMS message. In step 10 the MS / UE sends a delivery report to the MME. In step 11 the MME forwards the delivery report to MSC / VLR. In steps 12-13 the delivery report is forwarded to the SC. In steps 14-15 the MSC / VLR announces the receipt of the delivery report to the MS / UE. In step 16 the MSC / VLR informs the MME that no more NAS messages need to be tunneled.

When the MSC / VLR delivers the paging message to the MME as shown in step 5 of FIG. 4, the MSC / VLR may include an indicator for indicating that the paging message is paging for device triggering. The indicator may provide a new indicator value different from the service indicator value indicating the SMS indicator.

The MSC / VLR distinguishes paging for device triggering short message transmission when a paging message is transmitted by distinguishing a short message for device triggering through an SMS application port value assigned for device triggering included in a short message. You can send a message. SMS Application port ID to distinguish device triggering included in Submit Trigger message from MTC-IWF is one of TPDU (Transfer Protocol Data Unit) parameters by SMS-SC and is included in TP-UD (TP-User Data). By being included in the RP-UD (RP-User-Data) in the MT-DATA and transmitted, it can be distinguished from the MSC / VLR processing the relay layer protocol (RP).

And / or, the MSC / VLR may include an indicator for distinguishing the priority of the paging message. The indicator may allocate and provide a new indicator value different from the service indicator value indicating the SMS indicator according to the priority value.

And / or, if the MME is configured to do so, it may reduce the signaling load that the MSC / VLR generates on the MME. The MME may reject the paging message (step 5 of FIG. 4) when the MSC / VLR sends a short message for device triggering to the MME according to the mobile incoming SMS procedure through the SGs interface.

And / or the General NAS level Mobility Management Congestion Control or APN based Mobility Management Congestion Control or APN based Session Management Congestion Control Active / Performed, the MME may reject the paging message for sending a short message for device triggering sent by the MSC / VLR.

And / or network congestion when the MSC / VLR rejects paging to the MME for device triggering or fails to paging to the MME due to network congestion in the MME or NAS level mobility management congestion control or APN-based congestion control. A cause value to indicate that the trigger has failed, and / or a backoff timer may be included in the Delivery Report message and forwarded to the SMS-SC (steps 12 and 13 of FIG. 4).

And / or, the MSC receiving the backoff timer may prevent the paging message from being sent until the backoff timer expires. Alternatively, the paging message may not be transmitted by the short message including the normal priority value until the backoff timer expires.

And / or if the MSC receiving the backoff timer sends a paging message before the backoff timer expires, the MME sends a paging message before the backoff timer expires, including a cause value indicating that the trigger failed. I can send it.

And / or, if the MSC receiving the backoff timer sends a paging message with a short message containing a normal priority value before the backoff timer expires, the MME stores the backoff timer and subsequent. The Paging message may be rejected immediately, or the MSC may send a paging message before the backoff timer expires, including a cause value indicating that it failed.

And / or the emergency bearer service or high priority service even when the MSC receives a message containing a cause value indicating the cause of the failure condition due to network congestion. You can send a paging message. In this case, the paging message can be distinguished from the general paging message (e.g. by changing the SMS indicator value).

And / or, the back off timer may be stored per MTC device.

And / or the backoff timer may be stored per network entity (e.g. per MSC).

And / or to avoid sending / initiating (almost) simultaneously deferred paging messages to a large number of MTC devices, the MME must select a backoff timer value so that the deferred request is not synchronized.

And / or to avoid sending / initiating a (nearly) deferred Submit Trigger message to a large number of MTC devices, the MSC should select a backoff timer value such that the deferred request is not synchronized.

And / or the MME may reduce the signaling load that the SMS-SC or SMS-GMSC generates to the MME if it is configured to do so. When the mobile incoming SMS is delivered using the SMS in MME scheme, the MME may reject the SMS-SC when the SMS-SC forwards a short message for device triggering to the MME (step 4 of FIG. 3).

And / or, if the SMS-GMSC delivers a short message for device triggering to the MME, the MME may reject it.

And / or General NAS level Mobility Management Congestion Control or APN based Mobility Management Congestion Control (APN based Session Management Congestion Control) during the overload situation or in the MME. Active / Performed, if the SMS-SC or SMS-GMSC delivers a short message for device triggering, the MME may reject it.

And / or, if the MME rejects or stops delivery of a short message for device triggering due to network congestion or NAS level mobility management congestion control or APN-based congestion control in the MME, the trigger indicates that the network congestion failed. The cause value for indication and / or the backoff timer may be forwarded by being included in a delivery report message (eg, included in the RP-ERROR PDU).

SMS Application port ID to distinguish device triggering included in Submit Trigger message from MTC-IWF is one of TPDU (Transfer Protocol Data Unit) parameters by SMS-SC and is included in TP-UD (TP-User Data). By being included in the RP-UD (RP-User-Data) in the MT-DATA and transmitted, it can be distinguished by an MME (eg, an SMS in MME) that processes a relay layer protocol (RP).

And / or the SMS-SC or SMS-GMSC receiving the backoff timer may not transmit the paging message until the backoff timer expires. Alternatively, a short message including a normal priority value may not be delivered until the backoff timer expires.

And / or if the SMS-SC or SMS-GMSC receiving the backoff timer sends a paging message before the backoff timer expires, the MME sends a paging message before the backoff timer expires to indicate that the trigger failed. It can be sent with the cause value.

And / or, if the SMS-SC or SMS-GMSC backoff timer that received the backoff timer delivers a short message containing a normal priority value before it expires, the MME stores the backoff timer and follows ( The subsequent) Forward message can be rejected immediately, or the SMS-SC or SMS-GMSC can be sent with a cause value indicating that it failed by sending a paging message before the backoff timer expires.

And / or the emergency bearer service or high priority even when the SMS-SC or SMS-GMSC receives a message containing a cause value indicating the cause of the failure condition due to network congestion. A short message can be delivered for high priority service.

And / or, the back off timer may be stored per MTC device.

And / or the backoff timer may be stored for each network entity (e.g. per SMS-SC or per SMS-GMSC).

And / or if the MME fails to deliver a short message for device triggering due to network congestion or NAS level mobility management congestion control or APN-based congestion control in the MME, the MME displays an indication indicating that the device has failed to trigger due to network congestion. Can be set in the MME. If, subsequently, the MME recovers from congestion and an indication is set in the MME indicating that device triggering failed due to network congestion, the MME may send a Ready for SM message to the HSS. The MME may clear the indication that the device triggering failed due to network congestion.

And / or, if the MME fails to deliver a short message for device triggering due to network congestion or NAS level mobility management congestion control or APN-based congestion control in the MME, a cause value to indicate that the trigger has failed due to network congestion, And / or deliver the backoff timer to the SMS-SC via a Delivery Report message (eg included in the RP-ERROR PDU). At this time, the SMS-GMSC or SMS-SC may request to add an indication indicating that the HSS has failed to trigger the device due to network address and / or SC address to MWD (Message Waiting Data), and / or a backoff timer.

And / or, when an indication indicating that the device triggering failed due to network congestion is set, reception of a Ready for SM message or an Update Location Request message by the HSS may trigger an SMS alert procedure.

And / or, if the short message delivery fails due to network congestion in the MSC / MME / SGSN step 5 (Transfer Message) of FIG. 3 may be omitted.

7) The SMS-SC generates necessary CDR information. CDR information includes the SCS identifier. The CDR contains an SMS application port. The CDR information may include MTC group identifier information.

And / or the CDR information may include an indication indicating that device triggering failed due to network congestion.

8) The SMS-SC always sends a Message Delivery Report to the MTC-IWF. The message delivery report contains the reason code, trigger reference number, and SCS identifier.

According to another embodiment of the present invention, when the HSS stores / includes an indication indicating that the device has failed to trigger due to network congestion (eg, included in the MWD), the MTC-IWF interoperates subscriber information from the HSS. The indication may be confirmed to provide load control.

5 illustrates a device triggering procedure via Tsp for an embodiment of the present invention.

This will be described below with reference to Fig.

1) The SCS server sends a device trigger request message to the MTC-IWF. The device trigger request message includes MTC device identifier information (e.g. external identifier or MSISDN), SCS identifier information, trigger reference number, validity period, and trigger payload.

  2) The MTC-IWF receiving the trigger request message checks whether the SCS is authorized to send a trigger request and whether the SCS has exceeded the quota or rate of trigger submission through the Tsp. If this check fails, the MTC-IWF sends a device trigger confirm message with a cause value indicating the cause for the failure condition and the flow ends at this step.

 3) MTC-IWF extracts whether the SCS is authorized to trigger the UE, and maps an external identifier or MSISDN to IMSI, and extracts relevant HSS storage routing information (including the serving core node identifier of the MTC device). In order to and / or confirm the overload / congestion status of the serving core node to the HSS, a Subscriber Information Request message is sent to the HSS.

4) The HSS sends a Subscriber Information Response message. If the SCS receives a cause value indicating that it is not allowed to send a trigger message to the MTC device or that no valid subscription information was returned from the HSS, then the MTC-IWF displays the cause value indicating the cause for the failure condition. A Device Trigger Confirm message is sent along with the (cause value) and the flow stops at this step.

And / or if the HSS includes an indication in the Message Waiting Data (MWD) that the device triggered a failure due to network congestion, the MTC-IWF triggers the device with a cause value indicating the cause for the failure condition. A device trigger confirm is sent and the flow stops at this step.

And / or, if the HSS includes an indication indicating that the device has failed to trigger due to network congestion in the Message Waiting Data (MWD), the HSS may transmit a backoff timer to the MTC-IWF.

5a) The MTC-IWF selects a trigger delivery procedure based on the information received from the HSS and the local policy.

 If the T5 delivery procedure is selected, the MTC-IWF attempts the T5 trigger delivery procedure.

5b) If the T5 delivery procedure fails or is not supported by the serving node or UE, or if T4 delivery is selected at step 5a, the MTC-IWF attempts the T4 delivery procedure.

And / or the MTC-IWF in the MTC-IWF indicating that the T5 delivery procedure failed due to network congestion, and when receiving a backoff timer, the MTC-IWF indicates in the Submit Trigger message to SMS-SC that the network congestion failed. And transmit the cause value and / or the received backoff timer.

6) The MTC-IWF sends a Device Trigger Report message to the SCS server with the cause value indicating the success or failure of the trigger delivery and the cause of the failure. The trigger delivery report includes the external identifier or MSISDN and the trigger reference number. The MTC-IWF generates the necessary charging information including the external identifier or the MSISDN and the SCS identifier.

7) In response to the received device trigger, the MTC devices take some action in consideration of the contents of the trigger payload. This response typically includes immediate communication with the SCS or application server or the initiation of a later communication.

6 is a block diagram illustrating a configuration of an MME / SGSN according to an embodiment of the present invention.

Referring to FIG. 6, the MME / SGSN 600 includes a controller 610, a transmitter 620, and a receiver 630.

The receiver 630 may receive a short message for device triggering from the SMS-GMSC or the SMS-SC. Alternatively, the receiver 630 may receive a paging message for device triggering from the MSC. The paging message for device triggering may include an indicator indicating that the paging is for device triggering. Alternatively, the paging message for device triggering may be delivered through an SMS application port allocated for device triggering.

The controller 610 may determine whether the MME / SGSN 600 is overloaded due to network congestion.

When determined to be in the overloaded state, the transmitter 620 may transmit a message indicating the overload to the SMS-GMSC, SMS-SC or MSC. When determined to recover from the overloaded state, the transmitter 610 may transmit a Ready for SM message to the HSS.

7 is a block diagram showing the configuration of an MSC according to an embodiment of the present invention.

Referring to FIG. 7, the MSC 700 includes a controller 710, a transmitter 720, and a receiver 730.

The transmitter 720 may transmit a paging message for device triggering to the MME / SGSN. The paging message for device triggering may include an indicator indicating that the paging is for device triggering. Alternatively, the paging message for device triggering may be delivered through an SMS application port allocated for device triggering.

The receiver 730 may receive a message indicating the overload from the MME / SGSN.

The controller 710 may reduce traffic of a paging message for device triggering when receiving a message indicating an overload from the MME / SGSN.

When device triggering fails due to network congestion, the transmitter 720 may transmit a delivery report message including a backoff timer to the SMS-SC.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and variations without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (16)

An entity that performs mobility management in a network.
A receiving unit for receiving a short message for device triggering or a paging message for device triggering from an entity or mobile telephone exchange for transmitting a short message;
A controller for determining whether an overload condition is caused by network congestion; And
And a transmitter for transmitting a message indicating the overload to the mobile telephone exchange when the short message is determined to be overload. The method according to claim 1,
And the paging message for device triggering comprises an indicator indicating the paging for device triggering. The method according to claim 1,
And the receiving unit receives a paging message for device triggering through an SMS application port allocated for device triggering. The method according to claim 1,
And when the device recovers from the network congestion after the device triggering fails due to the network congestion, the transmitter transmits a short message preparation message to the subscriber management server. A transmitter for transmitting a paging message for device triggering to a mobility management entity;
A receiving unit for receiving a message indicating an overload from the mobility management entity; And
And a controller for reducing traffic of a paging message for device triggering upon receiving a message comprising a traffic reduction indication from the mobility management entity. 6. The method of claim 5,
And the paging message for device triggering comprises an indicator indicating the paging for device triggering. 6. The method of claim 5,
And the transmitting unit transmits a paging message for device triggering through an SMS application port allocated for device triggering. 6. The method of claim 5,
And when the device triggering fails due to network congestion, the transmitter transmits a delivery report message including a backoff timer to the entity that delivers the short message. A device triggering overload control method executed in an object performing mobility management function in a network.
Receiving a short message for device triggering or a paging message for device triggering from an entity or mobile telephone exchange carrying a short message.
Determining whether an overload condition is caused by network congestion; And
And when it is determined that the overload is determined, sending a message indicating the overload to the entity carrying the short message or the mobile telephone exchange. 10. The method of claim 9,
And the paging message for device triggering comprises an indicator indicating the paging for device triggering. 10. The method of claim 9,
The receiving step is a device triggering overload control method, characterized in that for receiving the paging message for device triggering via the SMS Application port assigned for device triggering. 10. The method of claim 9,
And recovering from the network congestion after the device triggering fails due to the network congestion, sending a short message preparation message to the subscriber management server. A device triggering overload control method executed in a mobile telephone exchange,
Sending a paging message for device triggering to the mobility management entity;
Receiving a message indicating an overload from the mobility management entity; And
Reducing the traffic of a paging message for device triggering when receiving a message comprising a traffic reduction indication from the mobility management entity. The method of claim 13,
And the paging message for device triggering comprises an indicator indicating the paging for device triggering. The method of claim 13,
The transmitting step is a device triggering overload control method, characterized in that for transmitting the paging message for device triggering via the SMS Application port assigned for device triggering. The method of claim 13,
And sending a delivery report message including a backoff timer to an entity that delivers a short message when the device triggering fails due to network congestion.

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