WO2019178840A1

WO2019178840A1 - Method and apparatus for data transmission

Info

Publication number: WO2019178840A1
Application number: PCT/CN2018/080206
Authority: WO
Inventors: Xiangfeng Guo; Xiangbin WAN; Meng GAO; Qiwen DONG; Xin Wang
Original assignee: Nokia Technologies Beijing Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Technologies Beijing Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2018-03-23
Filing date: 2018-03-23
Publication date: 2019-09-26
Anticipated expiration: 2020-09-23

Abstract

Method and apparatus for data transmission are disclosed. A method comprises receiving, at a first interworking function (IWF), a first message from a first network device, wherein a destination of the first message is a user equipment (UE); detecting that a second network device serving the UE is no longer in service; sending a paging request message for the UE to an alternative second network device; receiving, from a subscriber information storage, a request for canceling the UE's location; and sending, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

Description

METHOD AND APPARATUS FOR DATA TRANSMISSION

Technical Field

Embodiments of the disclosure generally relate to communication, and, more particularly, to methods and apparatus for data transmission

Background

Detailed descriptions of mobile communication networks and systems can be found in the literature, such as in particular in Technical Specifications published by standardization bodies such as for example 3GPP (3rd Generation Partnership Project) .

In such systems, a mobile terminal (or User Equipment UE) has access via a Radio Access Network (RAN) to a Core Network (CN) providing mobile communication services.

Examples of systems, such as for example 3GPP systems, include: 2G such as GSM (Global System for Mobile Communications) , 3G such as UMTS (Universal Mobile Telecommunications System) , 4G such as LTE-EPS (long term evolution-evolved packet system) .

For example, EPS Core Network comprises a PS (Packet-Switched) domain called EPC (Evolved Packet Core) . EPC comprises entities such as in particular MME (Mobility Management Entity) in charge of control plane functions such as in particular mobility management and paging procedure for MT (Mobile Terminated) services towards UEs in an idle mode. In EPS, CS (Circuit-Switched) services (such as for example voice services or other services such as SMS (Short Message Service) ) can be delivered as IP (Internet protocol) -based services, via PS domain EPC providing IP connectivity to an operator's IP network (for example IMS (IP Multimedia Subsystem) network) .

On the contrary, in systems such as GSM or UMTS (not specifically illustrated) , CS services (such as for example voice services or other services such as SMS) are delivered via CS domain. CS domain comprises entities such as in particular MSC/VLR (mobile switching center/visitor location register) in charge of control plane functions such as in particular mobility management and paging procedure for MT services towards UEs in an idle mode.

An interworking function (IWF) may act a gateway to enable 2G and 3G network elements to connect and communicate with 4G LTE network elements.

There may be a risk that MT CS services (e.g. CS calls, SMS) cannot be successfully delivered to a subscriber for a long period after a MME failure. Restoration of MT CS services during long MME failure is raised in 3GPP TS 29.118 and 3GPP TS 23.007, which are incorporated herein by reference in their entirety. If the MME serving a UE is detected that it is no longer in service and the MT CS services may be delivered via an alternative MME in a MME pool. For example, when the UE re-attaches to another IWF after sending a paging request message, SMS-GMSC/SC (SMS-gateway MSC/service center) may retransmit the SMS message using the existing SMS procedures as defined in 3GPP TS 23.007. However SC may depend on a timer, and perform SMS retransmission as a cron job to do retry for a “system failure” and will cause the SMS delivery delayed. Therefore, it would be desirable to provide an improved solution for MT CS services.

Summary

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

According to another aspect of the disclosure, it is provided a method. The method may comprise: receiving, at a first interworking function (IWF) , a first message from a first network device, wherein a destination of the first message is a user equipment (UE) ; detecting that a second network device serving the UE is no longer in service; sending a paging request message for the UE to an alternative second network device; receiving, from a subscriber information storage, a request for canceling the UE’s location; and sending, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided a method. The method may comprise: sending a first message to a first interworking function (IWF) , wherein a destination of the first message is a user equipment (UE) ; and receiving, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided a method. The method may comprise: receiving, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location; sending to a first IWF a request for canceling the UE’s location; receiving, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and when the UE’s location update is completed, sending, to the first network device, a message indicating that a first message can be retransmitted, wherein a destination of the first message is the UE.

According to another aspect of the disclosure, it is provided a method. The method may comprise: sending a first message to a first network device, wherein a destination of the first message is a user equipment (UE) ; receiving, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE; receiving, from the first network device, a message indicating that the first message can be retransmitted; and retransmitting the first message to the first network device.

According to another aspect of the disclosure, it is provided an apparatus. The apparatus may comprises: a processor; and a memory, the memory containing instructions executable by the processor, whereby the network device may be operative to: receive, at a first interworking function (IWF) , a first message from a first network device, wherein a destination of the first message is a user equipment (UE) ; detect that a second network device serving the UE is no longer in service; send a paging request message for the UE to an alternative second network device; receive, from a subscriber information storage, a request for canceling the UE’s location; and send, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided an apparatus. The apparatus may comprises: a processor; and a memory, the memory containing instructions executable by the processor, whereby the network device may be operative to: send a first message to a first interworking function (IWF) , wherein a destination of the first message is a user equipment (UE) ; and receive, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided an apparatus. The apparatus may comprises: a processor; and a memory, the memory containing instructions executable by the processor, whereby the network device may be operative to: receive, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location; send to a first IWF a request for canceling the UE’s location; receive, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and when the UE’s location update is completed, send, to the first network device, a message indicating that a first message can be retransmitted, wherein a destination of the first message is the UE.

According to another aspect of the disclosure, it is provided an apparatus. The apparatus may comprises: a processor; and a memory, the memory containing instructions executable by the processor, whereby the network device may be operative to: send a first message to a first network device, wherein a destination of the first message is a user equipment (UE) ; receive, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE; receive, from the first network device, a message indicating that the first message can be retransmitted; and retransmit the first message to the first network device.

According to another aspect of the disclosure, it is provided a computer program product. The computer program product comprises instructions which when executed by at least one processor, may cause the at least one processor to receive, at a first interworking function (IWF) , a first message from a first network device, wherein a destination of the first message is a user equipment (UE) ; detect that a second network device serving the UE is no longer in service; send a paging request message for the UE to an alternative second network device; receive, from a subscriber information storage, a request for canceling the UE’s location; and send, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided a computer program product. The computer program product comprises instructions which when executed by at least one processor, may cause the at least one processor to send a first message to a first interworking function (IWF) , wherein a destination of the first message is a user equipment (UE) ; and receive, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided a computer program product. The computer program product comprises instructions which when executed by at least one processor, may cause the at least one processor to receive, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location; send to a first IWF a request for canceling the UE’s location; receive, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and when the UE’s location update is completed, send, to the first network device, a message indicating that a first message can be retransmitted, wherein a destination of the first message is the UE.

According to another aspect of the disclosure, it is provided a computer program product. The computer program product comprises instructions which when executed by at least one processor, may cause the at least one processor to send a first message to a first network device, wherein a destination of the first message is a user equipment (UE) ; receive, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE; receive, from the first network device, a message indicating that the first message can be retransmitted; and retransmit the first message to the first network device.

According to another aspect of the disclosure, it is provided a computer readable storage medium. The computer readable storage medium comprises instructions which are executed by at least one processor and may cause the at least one processor to receive, at a first interworking function (IWF) , a first message from a first network device, wherein a destination of the first message is a user equipment (UE) ; detect that a second network device serving the UE is no longer in service; send a paging request message for the UE to an alternative second network device; receive, from a subscriber information storage, a request for canceling the UE’s location; and send, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided a computer readable storage medium. The computer readable storage medium comprises instructions which are executed by at least one processor and may cause the at least one processor to send a first message to a first interworking function (IWF) , wherein a destination of the first message is a user equipment (UE) ; and receive, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to another aspect of the disclosure, it is provided a computer readable storage medium. The computer readable storage medium comprises instructions which are executed by at least one processor and may cause the at least one processor to receive, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location; send to a first IWF a request for canceling the UE’s location; receive, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and when the UE’s location update is completed, send, to the first network device, a message indicating that a first message can be retransmitted, wherein a destination of the first message is the UE.

According to another aspect of the disclosure, it is provided a computer readable storage medium. The computer readable storage medium comprises instructions which are executed by at least one processor and may cause the at least one processor to send a first message to a first network device, wherein a destination of the first message is a user equipment (UE) ; receive, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE; receive, from the first network device, a message indicating that the first message can be retransmitted; and retransmit the first message to the first network device.

These and other objects, features and advantages of the disclosure will become apparent from the following detailed description of illustrative embodiments thereof, which are to be read in connection with the accompanying drawings.

Brief Description of the Drawings

Fig. 1 is a flow chart depicting a method of SMS restoration when MME is detected as failure;

Fig. 2 is a flow chart depicting a method according to an embodiment of the present disclosure;

Fig. 3 is a flow chart depicting a method according to another embodiment of the present disclosure;

Fig. 4 is a flow chart depicting a method according to another embodiment of the present disclosure;

Fig. 5 is a flow chart depicting a method according to another embodiment of the present disclosure;

Fig. 6 is a flow chart depicting a method according to another embodiment of the present disclosure;

Fig. 7 is a flow chart depicting a method according to another embodiment of the present disclosure;

Fig. 8 is a block diagram illustrating an apparatus according to an embodiment of the disclosure;

Fig. 9 is a block diagram illustrating an apparatus according to another embodiment of the disclosure;

Fig. 10 is a block diagram illustrating an apparatus according to another embodiment of the disclosure; and

Fig. 11 is a block diagram illustrating an apparatus according to another embodiment of the disclosure.

Detailed Description

For the purpose of explanation, details are set forth in the following description in order to provide a thorough understanding of the embodiments disclosed. It is apparent, however, to those skilled in the art that the embodiments may be implemented without these specific details or with an equivalent arrangement.

As used herein, the term “wireless communication network” or “wireless network” refers to a network following any suitable communication standards, such as LTE-Advanced (LTE-A) , LTE, Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , and so on. Furthermore, the communications between a terminal device and a network device in the wireless communication network may be performed according to any suitable generation communication protocols, including, but not limited to, GSM, UMTS, LTE, and/or other suitable 2G, 2.5G, 2.75G, 3G, 4G, 4.5G network.

The term “terminal device” refers to any end device that can access a wireless communication network and receive services therefrom. By way of example and not limitation, the terminal device refers to a mobile terminal, user equipment (UE) , or other suitable devices. The UE may be, for example, a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, portable computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, wearable terminal devices, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) and the like. In the following description, the terms “terminal device” , “terminal” , “user equipment” and “UE” may be used interchangeably. As one example, a terminal device may represent a UE configured for communication in accordance with one or more communication standards promulgated by the 3GPP, such as 3GPP’s GSM, UMTS, LTE standards. As used herein, a “user equipment” or “UE” may not necessarily have a “user” in the sense of a human user who owns and/or operates the relevant device. In some embodiments, a terminal device may be configured to transmit and/or receive information without direct human interaction. For instance, a terminal device may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the wireless communication network. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but that may not initially be associated with a specific human user.

The terminal device may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, and may in this case be referred to as a D2D communication device.

As yet another example, in an Internet of Things (IOT) scenario, a terminal device may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another terminal device and/or network equipment. The terminal device may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as a machine-type communication (MTC) device. As one particular example, the terminal device may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, for example refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a terminal device may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

References in the specification to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first” and “second” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed terms.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be liming of example embodiments. As used herein, the singular forms “a” , “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” , “comprising” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

It is noted that though the embodiments below are mainly described in the context of SMS, they are not limited to this but can be applied to any suitable MT CS services that can benefit from the embodiments as described herein.

Fig. 1 is a flow chart depicting a method of SMS restoration when MME is detected as failure. In this method, SC needs to start a timer and retransmit the SMS message when the timer is expired.

As shown in Fig. 1, SC sends a SMS to SMS-GMSC at step 102, wherein the destination of the SMS is a UE served by a 4G LTE network.

At step 104, SMS-GMSC sends a message MAP-SEND-ROUTING-INFO-FOR-SM to a home location register (HLR) associated with the UE to get routing information (i.e., IWF1) needed for routing the SMS message.

At step 106, SMS-GMSC sends a message MAP-MT-FORWARD-SHORT-MESSAGE to IWF1.

At step 108, IWF1 detects MME2 serving the UE is failure and then IWF1 may send a SGsAP-PAGING_REQUEST with a CS Restoration Indication to an alternate-MME (i.e., MME1) at step 110. Then MME1 may instruct one or more eNodeBs to page the UE and UE may reattach to MME1.

At step 112, MME1 sends a SGsAP-LOCATION-UPDATE-REQUEST to a different IWF, e.g. IWF2, and the UE re-attaches to IWF2.

At step 114, IWF2 sends MAP_UPDATE_LOCATION to HLR which may perform a location update procedure.

At step 116, HLR sends MAP_CANCEL_LOCATION to IWF1 to cancel the location information of UE on IWF1.

At step 118, IWF1 fails the SMS by sending MAP-MT-FORWARD-SHORT-MESSAGE-ACK with an indicator “system failure” to the SMS-GMSC.

At step 120, SMS-GMSC sends a delivery report with the indicator “system failure” to SC.

At step 122, SC starts a timer to wait for SMS retransmission.

At steps 124-136, SMS message may be retransmitted successfully.

Since SC depends on a timer and perform SMS retransmission as a cron job to do retry for a “system failure” , therefore it will cause the SMS delivery delayed. To overcome or mitigate the above-mentioned problem or other problems, the embodiments of the disclosure propose a new mobile application part (MAP) message indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE in parameter “User error” of the message MAP-MT-FORWARD-SHORT-MESSAGE-ACK. This Indicator may be used to indicate that UE reattaches to another IWF. Table 1 shows the parameter of the message MAP-MT-FORWARD-SHORT-MESSAGE parameter as defined by table 12.9/1 of 3GPP TS 29.002, which is incorporated herein by reference in its entirety.

Table 1

A new MAP message indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE in parameter “SM Delivery Outcome” is raised. This Indicator is used to indicate that UE reattaches to another IWF. Table 2 shows the parameter of the message MAP-REPORT-SM-DELIVERY-STATUS as defined by table 12.3/1 of 3GPP TS 29.002, which is incorporated herein by reference in its entirety.

Table 2

Parameter name	Request	Indication	Response	Confirm
Invoke Id	M	M (=)	M (=)	M (=)
MSISDN	M	M (=)
IMSI	C	C (=)
Service Centre Address	M	M (=)
SM Delivery Outcome	M	M (=)
Absent Subscriber Diagnostic SM	C	C (=)
GPRS Support Indicator	C	C (=)
Delivery Outcome Indicator	C	C (=)
Additional SM Delivery Outcome	C	C (=)
Additional Absent Subscriber Diagnostic SM	C	C (=)
IP-SM-GW-Indicator	C	C (=)
IP-SM-GW SM Delivery Outcome	C	C (=)
IP-SM-GW Absent Subscriber Diagnostic SM	C	C (=)
Single Attempt Delivery	C	C (=)
Correlation ID	C	C (=)
MSIsdn-Alert			C	C (=)
User error			C	C (=)
Provider error				O

It is noted that the indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE may take any other suitable form as long as it can indicate that the current IWF does not serve the UE and the UE may reattach to another IWF.

Fig. 2 is a flow chart depicting a method 200 according to an embodiment of the present disclosure.

As shown in Fig. 2, the method 200 may start at step 202 where SC may send a MT message to SMS-GMSC, wherein the destination of the MT message is a UE which may be served by a 4G LTE network. SC may obtain the MT message from any suitable entity, such as 2G/3G network or Public Switched Telephone Network (PSTN) . In an embodiment, the MT message is a SMS message.

At step 204, SMS-GMSC sends a message MAP-SEND-ROUTING-INFO-FOR-SM to a home location register (HLR) associated with the UE to get routing information (i.e., IWF1) needed for routing the SMS.

At step 206, SMS-GMSC sends a message MAP-MT-FORWARD-SHORT-MESSAGE to IWF1.

At step 208, IWF1 detects MME2 serving the UE is failure and then IWF1 may send a SGsAP-PAGING_REQUEST with a CS Restoration Indication to an alternate MME (i.e., MME1) at step 210. Then the MME1 may instruct one or more eNodeBs to page the UE. IWF1 may detect that MME2 serving the UE is failure by using any suitable existing methods. IWF1 may select the alternative MME in the MME pool. It is noted that though Fig. 2 only shows two MMEs in the MME pool, there may be any suitable number of MMEs in the MME pool.

At step 212, after the UE re-attaches to MME1, MME1 may send a SGsAP-LOCATION-UPDATE-REQUEST to a different IWF, e.g. IWF2. Then the UE re-attaches to IWF2. IWF1 and IWF2 may form an IWF pool. It is noted that though Fig. 2 only shows two IWFs in the IWF pool, there may be any suitable number of IWFs in the IWF pool.

At step 214, IWF2 may send MAP_UPDATE_LOCATION to HLR which may perform a location update procedure. Then HLR may perform location updating procedure as defined by 3GPP specification such as 3GPP TS 29.002.

At step 216, HLR sends MAP_CANCEL_LOCATION to IWF1 to cancel the location information of the UE on IWF1. It is noted that HLR may send MAP_CANCEL_LOCATION to IWF1 regardless of whether the location update procedure is finished or not.

At step 218, IWF1 may delete location information of the UE and fails the SMS message by sending MAP-MT-FORWARD-SHORT-MESSAGE-ACK with an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE to the SMS-GMSC. It is noted that the indicator may take any other suitable form such as “UE reattaches to another IWF” or “UE moved during paging” .

At step 220, SMS-GMSC may send a short message acknowledgement with the indicator to SC such that SC know the reason of SMS delivery failure and will not start a timer for SMS retransmission.

At step 222, SMS-GMSC sends a MAP-REPORT-SM-DELIVERY-STATUS with the indicator to HLR such that HLR know SMS delivery failure and SMS retransmission are needed when the location update procedure is completed.

At step 224, when the location update procedure is not completed, HLR may mark a Mobile Not Reachable Flag (MNRF) of the UE with the indicator.

At step 226, HLR may alert SMS-GMSC to retransmit the SMS when the location update procedure is completed and clear the MNRF of the UE.

At step 228, SMS-GMSC may alert SC to retransmit the SMS message.

At steps 230-242, SMS message may be retransmitted successfully.

Fig. 3 is a flow chart depicting a method 300 according to an embodiment of the present disclosure, which may be performed at an apparatus such as the SMS-GMSC of Fig. 2. As such, the apparatus may provide means for accomplishing various parts of the method 300 as well as means for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, detailed description thereof is omitted here for brevity.

As shown in Fig. 3, the method 300 may start at block 302 where the apparatus may send a first message to a first interworking function (IWF) , wherein the destination of the first message is a UE. The first message may comprise any suitable MT message such as SMS. The message may be obtained from any suitable party such as SC. The apparatus may retrieve, from a subscriber information storage such as HLR, routing information (i.e., the first IWF) needed for routing the first message.

At block 304, the apparatus may receive, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE. Then the apparatus may know the real reason of the first message delivery failure and can take any suitable actions such as getting the updated routing information from the HLR and alert SC to retransmit the first message.

Fig. 4 is a flow chart depicting a method 400 according to an embodiment of the present disclosure, which may be performed at an apparatus such as the SMS-GMSC of Fig. 2. As such, the apparatus may provide means for accomplishing various parts of the method 400 as well as means for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, detailed description thereof is omitted here for brevity.

At block 402, the apparatus may receive a first message such as SMS from a SC such as SMS-SC, wherein the destination of the first message is a UE.

At block 404, the apparatus may retrieve, from a subscriber information storage such as HLR, routing information needed for routing the first message. In this embodiment, the next hop of the first message is the first IWF.

At block 406, the apparatus may send the first message to the first IWF.

At block 408, the apparatus may receive, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

At block 410, the apparatus may send a message including the indicator to the SC such that SC will not start the timer for the first message retransmission.

At block 412, the apparatus may send a third message including the indicator to the subscriber information storage such as HLR which may send a message indicating that the first message can be retransmitted to the apparatus when the location update procedure is finished.

At block 414, the apparatus may receive, from the subscriber information storage, the message indicating that the first message can be retransmitted since the location updating procedure is completed.

At block 416, the apparatus may alert the service center to retransmit the first message. The first message retransmission procedure may be similar to that as defined by 3GPP specifications.

Fig. 5 is a flow chart depicting a method 500 according to an embodiment of the present disclosure, which may be performed at an apparatus such as the IWF1 of Fig. 2. As such, the terminal device may provide means for accomplishing various parts of the method 500 as well as means for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, detailed description thereof is omitted here for brevity.

As shown in Fig. 5, the method 500 may start at block 502 where IWF1 may receive a first message from a first network device, wherein the destination of the first message is a UE. The first message may comprise MT message such as SMS message. The first network device may be a 2G/3G network device such as SMS-GMSC.

At block 504, IWF1 may detect that a second network device serving the UE is no longer in service. The second network device may be a 4G network device such as MME.

At block 506, IWF1 may send a paging request message for the UE to an alternative second network device such as MME1, wherein MME1 and MME2 may belong to a MME pool. Then MME1 may instruct one or more eNodeBs to page the UE. In this embodiment, the UE may reattach to MME1 and IWF2. IWF2 may send a location updating request to HLR which may send a request for canceling the UE’s location to IWF1.

At block 508, IWF1 may receive, from a subscriber information storage such as HLR, the request for canceling the UE’s location. Then IWF1 may delete the UE’s location information and disassociate the UE from IWF1.

At block 508, IWF1 may send, to the first network device such as SMS-GMSC, a second message including an indicator indicating that the UE is detached from the first IWF (i.e., IWF1) or the first IWF does not serve the UE.

Fig. 6 is a flow chart depicting a method 600 according to an embodiment of the present disclosure, which may be performed at an apparatus such as the HLR of Fig. 2. As such, HLR may provide means for accomplishing various parts of the method 600 as well as means for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, detailed description thereof is omitted here for brevity.

As shown in Fig. 6, the method 600 may start at block 602 where HLR may receive, from a second IWF such as IWF2 of Fig. 2, a request for updating a UE’s location. For example, when UE reattaches to IWF2, IWF2 may send the request for updating the UE’s location to HLR, then HLR may receive the request.

At block 604, HLR may send to a first IWF such as IWF1 of Fig. 2 a request for canceling the UE’s location.

At block 606, HLR may receive, from a first network device such as SMS-GMSC of Fig. 2, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE. After receiving this message, HLR may know that a message delivery to the UE is failure since the UE re-attaches to the second IWF.

At block 608, when the UE’s location update procedure is completed, HLR may send, to the first network device such as SMS-GMSC, a message indicating that a first message such as SMS can be retransmitted, wherein the destination of the first message is the UE.

In an embodiment, when the UE’s location update is not completed, HLR may mark the UE’s flag with the indicator that the UE re-attaches to the second IWF. In an embodiment, the UE’s flag is a mobile not reachable flag (MNRF) .

Fig. 7 is a flow chart depicting a method 700 according to an embodiment of the present disclosure, which may be performed at an apparatus such as SC of Fig. 2. As such, the apparatus may provide means for accomplishing various parts of the method 700 as well as means for accomplishing other processes in conjunction with other components. For some parts which have been described in the above embodiments, detailed description thereof is omitted here for brevity.

As shown in Fig. 7, the method 700 may start at block 702 where SC may send a first message to a first network device, wherein the destination of the first message is a UE. The first message may comprise MT message such as SMS message. The first network device may be 2G/3G core network element such as SMS-GMSC.

At block 704, SC may receive, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE. The message may be a delivery report message. Then SC may know the reason of message delivery failure and will not start a timer for the first message retransmission.

At block 706, SC may receive, from the first network device, a message indicating that the first message can be retransmitted. For example, when the first network device know that the location update procedure for the UE is completed, the first network device may instruct SC to retransmit the first message.

At block 708, SC may retransmit the first message to the first network device. The subsequent procedure may similar to that as defined by the 3GPP specification.

According to various embodiments, the first message may comprise a short message, the subscriber information storage may comprise a HLR, the second message may comprise a message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and the third massage may comprise a message MAP-REPORT-SM-DELIVERY-STATUS.

According to various embodiments, the indicator may be included in a parameter “User error” of the message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and a parameter “SM Delivery Outcome” of the message MAP-REPORT-SM-DELIVERY-STATUS respectively.

Fig. 8 is a block diagram illustrating an apparatus capable of implementing the methods as described above. As shown in Fig. 8, the apparatus 800 comprises a processing device 804, a memory 805, and a transceiver 801 in operative communication with the processor 804. The transceiver 801 comprises at least one transmitter 802 and at least one receiver 803. While only one processor is illustrated in Fig. 8, the processing device 804 may comprises a plurality of processors or multi-core processor (s) . Additionally, the processing device 804 may also comprise cache to facilitate processing operations.

Computer-executable instructions can be loaded in the memory 805 and, when executed by the processing device 804, cause the apparatus 800 to implement the above-described methods. In particular, the computer-executable instructions can cause the apparatus 800 to send a first message to a first interworking function (IWF) , wherein the destination of the first message is a user equipment (UE) ; and receive, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

In an embodiment, the computer-executable instructions can further cause the apparatus 800 to receive the first message from a service center; retrieve, from a subscriber information storage, routing information needed for routing the first message; send a message including the indicator to the service center.

In an embodiment, the computer-executable instructions can further cause the apparatus 800 to send a third message including the indicator to the subscriber information storage; receive, from the subscriber information storage, a message indicating that the first message can be retransmitted; and alert the service center to retransmit the first message.

In an embodiment, the first message comprises a short message, the subscriber information storage comprises a home location register (HLR) , the second message comprises a message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and the third massage comprises a message MAP-REPORT-SM-DELIVERY-STATUS.

In an embodiment, the indicator is included in a parameter “User error” of the message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and a parameter “SM Delivery Outcome” of the message MAP-REPORT-SM-DELIVERY-STATUS respectively.

Fig. 9 is a block diagram illustrating an apparatus capable of implementing the methods as described above. As shown in Fig. 9, the apparatus 900 comprises a processing device 904, a memory 905, and a transceiver 901 in operative communication with the processor 904. The transceiver 901 comprises at least one transmitter 902 and at least one receiver 903. While only one processor is illustrated in Fig. 9, the processing device 904 may comprises a plurality of processors or multi-core processor (s) . Additionally, the processing device 904 may also comprise cache to facilitate processing operations.

Computer-executable instructions can be loaded in the memory 905 and, when executed by the processing device 904, cause the apparatus 900 to implement the above-described methods. In particular, the computer-executable instructions can cause the apparatus 900 to receive, at a first interworking function (IWF) , a first message from a first network device, wherein the destination of the first message is a user equipment (UE) ; detect that a second network device serving the UE is no longer in service; send a paging request message for the UE to an alternative second network device; receive, from a subscriber information storage, a request for canceling the UE’s location; and send, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

In an embodiment, the first message comprises a short message, the subscriber information storage comprises a home location register (HLR) , the first network device comprises 2G/3G network device, the second network device comprise 4G network device, the second message comprises a message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and the third massage comprises a message MAP-REPORT-SM-DELIVERY-STATUS.

Fig. 10 is a block diagram illustrating an apparatus capable of implementing the methods as described above. As shown in Fig. 10, the apparatus 1000 comprises a processing device 1004, a memory 1005, and a transceiver 1001 in operative communication with the processor 1004. The transceiver 1001 comprises at least one transmitter 1002 and at least one receiver 1003. While only one processor is illustrated in Fig. 10, the processing device 1004 may comprises a plurality of processors or multi-core processor (s) . Additionally, the processing device 1004 may also comprise cache to facilitate processing operations.

Computer-executable instructions can be loaded in the memory 1005 and, when executed by the processing device 1004, cause the apparatus 1000 to implement the above-described methods. In particular, the computer-executable instructions can cause the apparatus 1000 to receive, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location; send to a first IWF a request for canceling the UE’s location; receive, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and when the UE’s location update is completed, send, to the first network device, a message indicating that a first message can be retransmitted, wherein the destination of the first message is the UE.

In an embodiment, the computer-executable instructions can further cause the apparatus 1000 to mark the UE’s flag with the indicator when the UE’s location update is not completed.

In an embodiment, the first message comprises a short message. In an embodiment, the UE’s flag is a mobile not reachable flag (MNRF) .

Fig. 11 is a block diagram illustrating an apparatus capable of implementing the methods as described above. As shown in Fig. 11, the apparatus 1100 comprises a processing device 1104, a memory 1105, and a transceiver 1101 in operative communication with the processor 1104. The transceiver 1101 comprises at least one transmitter 1102 and at least one receiver 1103. While only one processor is illustrated in Fig. 11, the processing device 1104 may comprises a plurality of processors or multi-core processor (s) . Additionally, the processing device 1104 may also comprise cache to facilitate processing operations.

Computer-executable instructions can be loaded in the memory 1105 and, when executed by the processing device 1104, cause the apparatus 1100 to implement the above-described methods. In particular, the computer-executable instructions can cause the apparatus 1100 to send a first message to a first network device, wherein the destination of the first message is a user equipment (UE) ; receive, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE; receive, from the first network device, a message indicating that the first message can be retransmitted; and retransmit the first message to the first network device.

In an embodiment, the first message comprises a short message.

In an embodiment, the computer-executable instructions can cause the apparatus 1100 to not start a timer for the first message retransmission in response to receiving the massage including an indicator that the UE re-attaches to another IWF.

In an embodiment, the first network device is a short message service-gateway mobile switching center (SMS-GMSC) and the second network device is a mobility management entity (MME) .

According to an aspect of the disclosure it is provided a computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program instructions stored therein, the computer-executable instructions being configured to, when being executed, cause an apparatus such as SMS-GMSC to operate as described above.

According to an aspect of the disclosure it is provided a computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program instructions stored therein, the computer-executable instructions being configured to, when being executed, cause an apparatus such as IWF to operate as described above.

According to an aspect of the disclosure it is provided a computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program instructions stored therein, the computer-executable instructions being configured to, when being executed, cause an apparatus such as SC to operate as described above.

According to an aspect of the disclosure it is provided a computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program instructions stored therein, the computer-executable instructions being configured to, when being executed, cause an apparatus such as HLR to operate as described above.

According to an aspect of the disclosure it is provided an apparatus. The apparatus may comprise means for sending a first message to a first interworking function (IWF) , wherein the destination of the first message is a user equipment (UE) ; and means for receiving, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

In an embodiment, the apparatus may further comprise means for receiving the first message from a service center; means for retrieving, from a subscriber information storage, routing information needed for routing the first message; means for sending a message including the indicator to the service center; means for sending a third message including the indicator to the subscriber information storage; means for receiving, from the subscriber information storage, a message indicating that the first message can be retransmitted; and means for alerting the service center to retransmit the first message.

According to an aspect of the disclosure it is provided an apparatus. The apparatus may comprise means for receiving, at a first interworking function (IWF) , a first message from a first network device, wherein the destination of the first message is a user equipment (UE) ; means for detecting that a second network device serving the UE is no longer in service; means for sending a paging request message for the UE to an alternative second network device; means for receiving, from a subscriber information storage, a request for canceling the UE’s location; and means for sending, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.

According to an aspect of the disclosure it is provided an apparatus. The apparatus may comprise means for receiving, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location; means for sending to a first IWF a request for canceling the UE’s location; means for receiving, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and when the UE’s location update is completed, means for sending, to the first network device, a message indicating that a first message can be retransmitted, wherein the destination of the first message is the UE.

In an embodiment, the apparatus may further comprise means for marking the UE’s flag with the indicator when the UE’s location update is not completed.

According to an aspect of the disclosure it is provided an apparatus. The apparatus may comprise means for sending a first message to a first network device, wherein the destination of the first message is a user equipment (UE) ; means for receiving, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE; means for receiving, from the first network device, a message indicating that the first message can be retransmitted; and means for retransmit the first message to the first network device.

In an embodiment, the apparatus may comprise means for not starting a timer for the first message retransmission in response to receiving the massage including an indicator that the UE re-attaches to another IWF,

Advantages of the embodiments may comprise: SMS-GMSC/SC can get the real reason for the message (such as SMS) delivery failure, for example, UE re-attaches to another IWF due to MME failure. Therefore SMS-GMSC/SC needn’t to wait a timer expire. SMS-GMSC/SC can take corresponding action to find out a new IWF and retransmit the SMS directly.

It is noted that any of the components of the apparatus such as SMS-GMSC, IWF, HLR and SC can be implemented as hardware or software modules. In the case of software modules, they can be embodied on a tangible computer-readable recordable storage medium. All of the software modules (or any subset thereof) can be on the same medium, or each can be on a different medium, for example. The software modules can run, for example, on a hardware processor. The method steps can then be carried out using the distinct software modules, as described above, executing on a hardware processor.

The terms “computer program” , “software” and “computer program code” are meant to include any sequences or human or machine cognizable steps which perform a function. Such program may be rendered in virtually any programming language or environment including, for example, C/C++, Fortran, COBOL, PASCAL, assembly language, markup languages (e.g., HTML, SGML, XML) , and the like, as well as object-oriented environments such as the Common Object Request Broker Architecture (CORBA) , JavaTM (including J2ME, Java Beans, etc. ) , Binary Runtime Environment (BREW) , and the like.

The terms “memory” and “storage device” are meant to include, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the memory or storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

In any case, it should be understood that the components illustrated herein may be implemented in various forms of hardware, software, or combinations thereof, for example, application specific integrated circuit (s) (ASICS) , functional circuitry, an appropriately programmed general purpose digital computer with associated memory, and the like. Given the teachings of the disclosure provided herein, one of ordinary skill in the related art will be able to contemplate other implementations of the components of the disclosure.

The descriptions of the various embodiments have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims

A method, comprising:

receiving, at a first interworking function (IWF) , a first message from a first network device, wherein a destination of the first message is a user equipment (UE) ;

detecting that a second network device serving the UE is no longer in service;

sending a paging request message for the UE to an alternative second network device;

receiving, from a subscriber information storage, a request for canceling the UE’s location; and

sending, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.
The method according to claim 1, wherein the first message comprises a short message, the first network device comprises 2G/3G network device, the second network device comprise 4G network device, the subscriber information storage comprises a home location register (HLR) , the second message comprises a message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and the third massage comprises a message MAP-REPORT-SM-DELIVERY-STATUS.
The method according to claim 2, wherein the indicator is included in a parameter “User error” of the message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and a parameter “SM Delivery Outcome” of the message MAP-REPORT-SM-DELIVERY-STATUS respectively.
The method according to any of claims 1-3, wherein the first network device is a short message service-gateway mobile switching center (SMS-GMSC) and the second network device is a mobility management entity (MME) .
A method, comprising:

sending a first message to a first interworking function (IWF) , wherein a destination of the first message is a user equipment (UE) ; and

receiving, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.
The method according to claim 5, further comprising:

receiving the first message from a service center;

retrieving, from a subscriber information storage, routing information needed for routing the first message;

sending a message including the indicator to the service center.
The method according to claim 6, further comprising:

sending a third message including the indicator to the subscriber information storage;

receiving, from the subscriber information storage, a message indicating that the first message can be retransmitted; and

alerting the service center to retransmit the first message.
The method according to claim 7, wherein the first message comprises a short message, the subscriber information storage comprises a home location register (HLR) , the second message comprises a message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and the third massage comprises a message MAP-REPORT-SM-DELIVERY-STATUS.
The method according to claim 8, wherein the indicator is included in a parameter “User error” of the message MAP-MT-FORWARD-SHORT-MESSAGE-ACK and a parameter “SM Delivery Outcome” of the message MAP-REPORT-SM-DELIVERY-STATUS respectively.
A method, comprising:

receiving, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location;

sending to a first IWF a request for canceling the UE’s location;

receiving, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and

when the UE’s location update is completed, sending, to the first network device, a message indicating that a first message can be retransmitted, wherein a destination of the first message is the UE.
The method according to claim 10, further comprising

when the UE’s location update is not completed, marking the UE’s flag with the indicator.
The method according to claim 11, wherein the UE’s flag is a mobile not reachable flag (MNRF) .
The method according to any one of claims 10-12, wherein the first message comprises a short message.
The method according to any of claims 10-13, wherein the first network device is a short message service-gateway mobile switching center (SMS-GMSC) .
A method, comprising:

sending a first message to a first network device, wherein a destination of the first message is a user equipment (UE) ;

receiving, from the first network device, a massage including an indicator that indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE;

receiving, from the first network device, a message indicating that the first message can be retransmitted; and

retransmitting the first message to the first network device.
The method according to claim 15, wherein the first message comprises a short message.
The method according to claim 15 or 16, further comprising

in response to receiving the massage including an indicator that the UE re-attaches to another IWF, not starting a timer for the first message retransmission.
The method according to any of claims 15-17, wherein the first network device is a short message service-gateway mobile switching center (SMS-GMSC) .
An apparatus, comprising:

a processor; and

a memory, the memory containing instructions executable by the processor, whereby the apparatus is operative to:

receive, at a first interworking function (IWF) , a first message from a first network device, wherein a destination of the first message is a user equipment (UE) ;

detect that a second network device serving the UE is no longer in service;

send a paging request message for the UE to an alternative second network device;

receive, from a subscriber information storage, a request for canceling the UE’s location; and

send, to the first network device, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.
The apparatus according to claim 19, wherein the apparatus is operative to perform the method of any one of claims 2 to 4.
An apparatus, comprising:

a processor; and

a memory, the memory containing instructions executable by the processor, whereby the apparatus is operative to:

send a first message to a first interworking function (IWF) , wherein a destination of the first message is a user equipment (UE) ; and

receive, from the first IWF, a second message including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE.
The apparatus according to claim 21, wherein the apparatus is operative to perform the method of any one of claims 6 to 9.
An apparatus, comprising:

a processor; and

a memory, the memory containing instructions executable by the processor, whereby the apparatus is operative to:

receive, from a second interworking function (IWF) , a request for updating a user equipment (UE) ’s location;

send to a first IWF a request for canceling the UE’s location;

receive, from a first network device, a massage including an indicator indicating that the UE is detached from the first IWF or the first IWF does not serve the UE; and

when the UE’s location update is completed, send, to the first network device, a message indicating that a first message can be retransmitted, wherein a destination of the first message is the UE.
The apparatus according to claim 23, wherein the apparatus is operative to perform the method of any one of claims 11 to 14.
An apparatus, comprising:

a processor; and

a memory, the memory containing instructions executable by the processor, whereby the apparatus is operative to:

send a first message to a first network device, wherein a destination of the first message is a user equipment (UE) ;

receive, from the first network device, a massage including an indicator indicating that the UE is detached from a first interworking function (IWF) or the first IWF does not serve the UE;

receive, from the first network device, a message indicating that the first message can be retransmitted; and

retransmit the first message to the first network device.
The apparatus according to claim 25, wherein the apparatus is operative to perform the method of any one of claims 16 to 18.
A computer program product comprising instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 1 to 4.
A computer program product comprising instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 5 to 9.
A computer program product comprising instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 10 to 14.
A computer program product comprising instructions which when executed by at least one processor, cause the at least one processor to perform the method according to any one of claims 15 to 18.