阅读说明：本技术 针对启用eDRX的移动终端的MT SM传送的增强 (Enhancements for MT SM transfer for eDRX-enabled mobile terminals ) 是由 杨涌 陈骞 于 2016-11-16 设计创作，主要内容包括：本发明涉及使能将移动终接(MT)短消息(SM)传送到移动终端的移动性管理节点和所述移动性管理节点的方法。在本发明的第一方面,提供了一种移动性管理节点的使能将移动终接MT短消息SM传送到当前处于扩展空闲模式不连续接收eDRX模式的移动终端的方法。所述方法包括：从短消息服务网关移动交换中心(SMS-GMSC)接收所述SM将要被传送的指示；接收移动终端在寻呼时机发生之前已退出扩展空闲不连续接收(eDRX)模式的通知；以及响应于所述通知,提交向所述SMS-GMSC指示所述移动终端可用于所述SM的传送的消息。(The present invention relates to a mobility management node and a method of said mobility management node enabling the delivery of a Mobile Terminated (MT) Short Message (SM) to a mobile terminal. In a first aspect of the present invention, a method of a mobility management node enabling the delivery of a mobile terminated MT short message SM to a mobile terminal currently in extended idle mode discontinuous reception, eDRX, mode is provided. The method comprises the following steps: receiving an indication from a short message service gateway mobile switching center (SMS-GMSC) that the SM is to be delivered; receiving a notification that the mobile terminal has exited an extended idle discontinuous reception (eDRX) mode before a paging occasion occurs; and in response to the notification, submitting a message indicating to the SMS-GMSC that the mobile terminal is available for delivery by the SM.)

1. A method of a mobility management node (20) of enabling delivery of a mobile terminated, MT, short message, SM, to a mobile terminal (10), the method comprising:

receiving (S101) from a short message service gateway mobile switching center (40), SMS-GMSC, an indication that the SM is to be transmitted to the mobile terminal (10) currently in an extended idle mode discontinuous reception, eDRX, mode;

receiving (S102) a notification that the mobile terminal (10) has exited the eDRX mode before a paging occasion for the mobile terminal (10) occurred; and

in response to the notification, submitting (S103) a message to the SMS-GMSC (40) indicating to the SMS-GMSC (40) that the mobile terminal (10) is available for transmission of the SM.

2. The method of claim 1, the message being submitted directly to the SMS-GMSC (40).

3. The method of claim 1, the message being submitted to the SMS-GMSC via a home subscription server (50), HSS.

4. The method of claim 3, wherein the message submitted to the SMS-GMSC via the HSS further comprises an instruction instructing the HSS to provide the destination address for mobility management to the SMS-GMSC.

5. The method according to any of the preceding claims, the notification being a non-access stratum, NAS, request received (S102) from the mobile terminal (10).

6. The method of any of the preceding claims, further comprising:

receiving (S104) the SM from the SMS-GMSC (40) for transmission to the mobile terminal (10).

7. The method according to any of claims 1 to 3, the notification being a context request received (S102b) from a serving mobility management node (30) of the mobile terminal (10), the method further comprising:

submitting (S102c) a context response to the serving mobility management node (30) including an indication that the SM is to be transmitted; and

receiving (S102d), from the serving mobility management node (30), a context acknowledgement comprising a destination address of the serving mobility management node (30) for SM transfer, wherein the submitted (S103) message further comprises the destination address of the serving mobility management node (30).

8. The method of any of claims 1 to 3, the notification being a context request received (S102b) from a serving mobility management node (30) of the mobile terminal, the message being submitted (S103a) to the SMS-GSMC (40) in a context response (S102c) via the serving mobility management node (30) and further comprising a destination address of the SMS-GSMC (40).

9. The method of any of the preceding claims, receiving (S101) an indication from an SMS-GMSC (40) that the SM is to be transmitted, comprising:

receiving (S101a) an indication of a maximum retransmission time specifying how long the SMS-GMSC (40) will store the SM if the SM cannot be immediately transmitted and a capability indication indicating whether the SMS-GMSC (40) supports receiving a subsequent notification of mobile terminal availability for transmitting the SM, the method further comprising:

submitting (S101b) an indication to the SMS-GMSC (40) comprising a request retransmission time indicating at which point in time the SMS-GMSC (40) should retransmit the SM and a capability acknowledgement indicating that the mobility management node (20) supports the subsequent notification of mobile terminal availability for transmitting the SM.

10. A method of a mobility management node (30) of enabling delivery of a mobile terminated, MT, short message, SM, to a mobile terminal (10), the method comprising:

receiving (S102a) a notification that the mobile terminal (10) has exited an extended idle mode discontinuous reception, eDRX, mode before a paging occasion occurred;

submitting (S102b) a context request to another mobility management node (20) serving the mobile terminal (10) before the notification is received;

receiving (S102c), from the other mobility management node (20), a context response comprising an indication that the SM is to be transmitted; and

receiving (S105) the SM from the SMS-GMSC (40) for transmission to the mobile terminal (10).

11. The method of claim 10, the message being submitted directly to the SMS-GMSC (40).

12. The method of claim 10, the message being submitted to the SMS-GMSC (40) via a home subscription server, HSS, the message submitted to the SMS-GMSC via the HSS further comprising an instruction instructing the HSS to provide the destination address for mobility management to the SMS-GMSC.

13. The method of any of claims 10, 11, or 12, the submitted message further indicating a period of time specifying a time until the mobile terminal enters the eDRX mode again.

14. A mobility management node (20) configured to enable delivery of a mobile-terminated, MT, short message, SM, to a mobile terminal (10), and the mobility management node (20) comprising a processing unit (21) and a memory (23), the memory containing instructions (22) executable by the processing unit, whereby the mobility management node (20) is operable to:

receiving an indication from a short message service gateway mobile switching center (40), SMS-GMSC, that the SM is to be transmitted to the mobile terminal (10) currently in an extended idle mode discontinuous reception, eDRX, mode;

receiving a notification that the mobile terminal (10) has exited the eDRX mode before a paging occasion occurred; and

in response to the notification, submitting a message indicating to the SMS-GMSC (40) that the mobile terminal (10) is available for delivery of the SM.

15. The mobility management node (20) of claim 14, the mobility management node (20) being operable to submit the message directly to the SMS-GMSC (40).

16. The mobility management node (20) of claim 14, the mobility management node (20) being operable to submit the message to the SMS-GMSC via a home subscription server (50), HSS.

17. The mobility management node (20) of claim 16, the mobility management node (20) further operable to include in the message submitted to the SMS-GMSC (40) via the HSS (50) an instruction instructing the HSS (50) to provide the destination address for mobility management to the SMS-GMSC (40).

18. The mobility management node (20) according to any of claims 14-17, the notification being a non-access stratum, NAS, request received from the mobile terminal (10).

19. The mobility management node (20) according to any of claims 14-16, the notification being a context request received (S102b) from a serving mobility management node (30) of the mobile terminal (10), the mobility management node further operable to:

submitting a context response to the serving mobility management node (30) comprising an indication that the SM is to be transmitted; and

receiving, from the serving mobility management node (30), a context acknowledgement comprising a destination address of the serving mobility management node (30) for SM transfer, wherein the submitted (S103) message further comprises the destination address of the serving mobility management node (30).

20. The mobility management node (20) of any of claims 14-16, the notification being a context request received from a serving mobility management node (30) of the mobile terminal, the mobility management node (20) being further operable to submit the message to the SMS-GSMC (40) in a context response (S102c) via the serving mobility management node (30), and being further operable to include a destination address of the SMS-GSMC (40).

21. The mobility management node (20) of any of claims 14-20, the mobility management node (20) further operable to, upon receiving an indication from an SMS-GMSC (40) that the SM is to be transmitted:

receiving an indication of a maximum retransmission time specifying how long the SMS-GMSC (40) will store the SM if the SM cannot be immediately transmitted and a capability indication indicating whether the SMS-GMSC (40) supports receiving subsequent notifications of mobile terminal availability for transmitting the SM; and

submitting an indication to the SMS-GMSC (40) comprising a request for retransmission time indicating at which point in time the SMS-GMSC (40) should retransmit the SM and a capability acknowledgement indicating that the mobility management node (20) supports the subsequent notification of mobile terminal availability for transmitting the SM.

22. A mobility management node (30) configured to enable delivery of a mobile-terminated, MT, short message, SM, to a mobile terminal (10), and the mobility management node (30) comprising a processing unit (31) and a memory (33), the memory containing instructions (32) executable by the processing unit, whereby the mobility management node (30) is operable to:

receiving a notification that the mobile terminal (10) has exited an extended idle mode discontinuous reception, eDRX, mode before a paging occasion occurred;

submitting a context request to another mobility management node (20) serving the mobile terminal (10) before the notification is received;

receiving a context response from the other mobility management node (20) comprising an indication that the SM is to be transmitted; and

receiving the SM from the SMS-GMSC (40) for transmission to the mobile terminal (10).

23. The mobility management node (30) of claim 22, the mobility management node (30) further operable to submit the message directly to the SMS-GMSC (40).

24. The mobility management node (30) of claim 22, the mobility management node (30) further operable to submit the message to the SMS-GMSC (40) via a home subscription server, HSS, the message submitted to the SMS-GMSC via the HSS further comprising an instruction instructing the HSS to provide a destination address for the mobility management to the SMS-GMSC.

25. The mobility management node (20, 30) according to any of claims 22-24, the mobility management node (20, 30) further operable to include in the submitted message a time period specifying a time until the mobile terminal enters the eDRX mode again.

26. A computer program (22) comprising computer executable instructions which, when executed on a processing unit (21) comprised in a device (20), cause the device to perform the steps according to any one of claims 1 to 9.

27. A computer program product comprising a computer readable medium (23) on which is embodied a computer program (22) according to claim 26.

28. A computer program (32) comprising computer executable instructions which, when executed on a processing unit (31) comprised in a device (30), cause the device to perform the steps according to any of claims 10 to 12.

29. A computer program product comprising a computer readable medium (33) on which the computer program (32) according to claim 28 is embodied.

Technical Field

The present invention relates to a mobility management node and a method of said mobility management node enabling the delivery of a Mobile Terminated (MT) Short Message (SM) to a mobile terminal.

The invention also relates to a computer program for causing a mobility management node to perform a method according to the invention, and a corresponding computer program product.

Background

Short Message Service (SMS) provides a means to send messages of limited size to and from mobile terminals in third generation partnership project (3GPP) communication systems such as global system for mobile communications (GSM), Universal Mobile Telecommunications System (UMTS), and Evolved Packet System (EPS). The provision of SMS makes use of a service centre which acts as a repository and forwarding centre for short messages.

Messages originating from the mobile terminal are transmitted from the terminal to the service center, whereas mobile-terminated messages should be transmitted from the service center to the terminal. Short messages are typically entered into the service center by other mobile users and then sent to other mobile users or users on the fixed network. This process is described in detail in the technical specification 3GPP TS 23.040.

Now, in order to extend the battery life of mobile terminals, a method called Discontinuous Reception (DRX) is used, wherein a mobile terminal, usually called User Equipment (UE), only occasionally monitors a Physical Downlink Control Channel (PDCCH) to check if downlink data is available.

Recently introduced UE types such as Machine Type Communication (MTC) devices require very efficient power saving, which leads to the introduction of a mode known as extended idle mode drx (edrx). That is, the UE and the network may negotiate on non-access stratum (NAS) signaling to use extended idle mode DRX to reduce their power consumption while being available for mobile terminated data and/or network initiated procedures within a certain delay that depends on the DRX cycle value. eDRX-enabled UEs can only reach through the network (i.e., page through the network) during their Page Transmission Window (PTW), and during this window, the UEs use normal DRX.

The transfer of Mobile Terminated (MT) Short Messages (SM) from a Short Message Service Center (SMSC) to a Mobility Management Entity (MME) is described in "MT SMS procedures for UEs in extended idle mode DRX, C4-152115, 3GPP TSG CT4, conference 71, Anaheim, USA; 11 months, 16 days to 20 days 2015)".

Reference is made to the timing diagram of figure 1.

The SMSC submits a Send-Routing-Info-for-SM-request (srr) command to the Home Subscriber Server (HSS) to retrieve the address of the node serving the UE.

The HSS responds accordingly by submitting a Send-Routing-Info-for-SM-answer (sra) message indicating the address of the serving MME.

The SMSC sends MT-Forward-Short-Message-request (TFR) to the serving MME. The SMSC indicates in the TFR a maximum retransmission time (e.g. 5 to 10 minutes) indicating how long the SMSC is ready to store the SM in case it cannot transmit the SM immediately due to the UE being in extended idle mode DRX.

4. If the UE is reachable within the maximum retransmission time provided in the TFR, the MME immediately sends MT-Forward-Short-Message-Request-answer (TFA) in step 4a, the TFA indicating the requested retransmission time, i.e. the time the SM should be retransmitted by the SMSC. The MME also pages the UE in 4 b.

At this stage, the SMSC will not send a Report-SM-Delivery-Status-request (RDR) to the HSS indicating that the SM transfer failed. Thus, the HSS will not use the Report-SM-Delivery-Status-answer (rda) message reply, nor will it store the service centre address in its Message Waiting Data (MWD).

5. At the point in time when the signaling connection is established between the UE and the MME, the UE responds to the paging.

At this stage, the MME does not send a Notify-request (nor) to the HSS to inform the UE that it has become reachable.

The request retransmission time indicated in TFA by SMSC (the maximum retransmission time is not included in this second transmission of TFR) retransmits SM.

A solution in "MT SMS procedures for UEs in extended idle mode DRX (MT SMS procedures for UEs in extended idle mode DRX)" is described to present the following advantages:

a. the MT SM of a UE in eDRX does not cause any additional HSS signaling.

b. There is no problem with synchronizing messages received at the HSS for a short eDRX period (e.g. up to 20 seconds).

c. If this procedure is used, a Single-attribute-delivery SM can be sent to the UE (MWD for Single-attribute-delivery SM is not needed because it was previously specified).

The solution in "MT SMS procedures for UEs in extended idle mode DRX (MT SMS procedure for UEs in extended idle mode DRX)" is further described to present the following disadvantages:

a. SM retransmission is triggered without determining whether the UE is indeed reachable (e.g., the UE may have detached, the UE may be in a tunnel, the eDRX period may have been renegotiated, etc.).

b. The impact on SMSC is greater (buffering of MT-SM is extended, e.g. up to 5 to 10 minutes).

c. The Mobile Station Not Reachable Flag (MNRF) Flag is Not set in the HSS, so subsequent MT SMs sent from different SMSCs to the same UE will trigger a new MT forwarded SM Request to the MME for the unreachable UE.

d. Another method is introduced to deliver MT SMS for a UE using extended idle mode DRX.

The applicant has perceived other drawbacks of this solution, as will be discussed with reference to fig. 2.

As shown in fig. 1, the SMSC submits the TFR to the currently serving MME (MME1) to indicate that the SM is to be submitted to the UE. The TFR includes a maximum retransmission time that indicates how long the SMSC is ready to store the SM when it cannot immediately transmit the SM because the UE is in eDRX.

The MME1 responds accordingly with a TFA indicating the request retransmission time at which the SMSC should retransmit the SM, then pages the UE when the next paging occasion occurs (occurring just before the start of the next paging transmission window, i.e., occurring just before the indicated request retransmission time), so that when the UE wakes up from its eDRX cycle at the request retransmission time, the SM can be timely transmitted from the SMSC to the UE via the MME 1.

Now, in this particular example MME1, a first problem arises if the UE wakes up from its eDRX cycle before being paged by the serving mobility management node, exiting eDRX mode (e.g., due to a UE service request sending data), and accordingly initiates NAS signaling to its currently serving mobility management node (e.g., MME or serving GPRS (general packet radio service) support node (SGSN)).

For long term evolution/evolved universal terrestrial access network (LTE/E-UTRAN) access, non-radio signaling is transported between the UE and the MME using NAS signaling. For example, the NAS request may be a Routing Area Update (RAU) request to update the location of a UE within the network. When the UE detects that it enters a new routing area, the UE initiates RAU and will therefore contact the core network (current serving SGSN or new SGSN).

Thus, the first problem can be illustrated as occurring in the case of an intra-SGSN RAU request, i.e. when a UE enters a new routing area but is still serving SGSN (by SGSN in fig. 2)₁Example) at the time of the day. When the SMSC attempts to submit the SM to the UE at the TFA specified retransmission request time, there is a risk that the UE enters eDRX mode again, resulting in a failure of the scheduled MT-SMs delivery. When the UE is camped on UTRAN, the eDRX cycle will be restarted at each routing area update procedure.

When the UE is camped in E-UTRAN and GSM, the paging occasion scheme may be maintained if the serving MME or SGSN maintains the eDRX cycle regardless of whether the UE requests a change of eDRX cycle at the TAU/RAU. In this case the problem is less cumbersome, but the MT-SMS will still unnecessarily delay to the next scheduled paging occasion, requiring additional signaling to the UE, and the UE power consumption increases, which should actually be avoided.

In addition, in UBefore E responds to the paging message from the network, if the UE initiates an NAS request to another mobility management node, two management nodes called inter-MME TAU requests (the other node is made by the MME in fig. 2)₂Instantiating) an idle mode mobility procedure, a second problem arises. That is, the paging message has not been sent by the first mobility management node because the paging window has not occurred.

For example, if at the MME₁This problem occurs when the UE initiates an MME TAU request after reporting the request retransmission time (which indicates the next paging occasion based on the eDRX cycle) to the SMSC, but before the actual paging occasion occurs.

In this case, the SMSC will deliver the MT-SMS to the wrong MME (i.e., MME) at the TFA specified request retransmission time₁)。

Disclosure of Invention

It is an object of the present invention to solve or at least partly mitigate at least one of these problems in the art and thus to provide an improved method of facilitating the delivery of short messages to eDRX mode enabled mobile terminals.

In a first aspect of the present invention, this object is achieved by a method of a mobility management node enabling the delivery of a mobile-terminated MT short message SM to a mobile terminal currently in eDRX mode. The method comprises the following steps: receiving an indication from a short message service gateway mobile switching center (SMS-GMSC) that the SM is to be delivered; receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs; and in response to the notification, submitting a message indicating to the SMS-GMSC that the mobile terminal is available for delivery by the SM.

In a second aspect of the present invention, this object is achieved by a mobility management node configured to enable delivery of an MT SM to a mobile terminal currently in extended eDRX mode, and comprising a processing unit and a memory, said memory containing instructions executable by said processing unit, whereby said mobility management node is operative to: receiving an indication from the SMS-GMSC that the SM is to be delivered; receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs; and in response to the notification, submitting a message indicating to the SMS-GMSC that the mobile terminal is available for delivery by the SM.

In a third aspect of the present invention, this object is achieved by a method of a mobility management node enabling delivery of an MT SM to a mobile terminal currently in eDRX mode, the method comprising: receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs; submitting a context request to another mobility management node serving the mobile terminal before the notification is received; receiving a context response from the other mobility management node comprising an indication that the SM is to be transmitted; and receiving the SM from the SMS-GMSC for transmission to the mobile terminal.

In a fourth aspect of the present invention, this object is achieved by a mobility management node configured to enable delivery of an MT SM to a mobile terminal currently in eDRX mode, and comprising a processing unit and a memory, said memory containing instructions executable by said processing unit, whereby said mobility management node is operative to: receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs; submitting a context request to another mobility management node serving the mobile terminal before the notification is received; receiving a context response from the other mobility management node comprising an indication that the SM is to be transmitted; and receiving the SM from the SMS-GMSC for transmission to the mobile terminal.

In one embodiment, the message is submitted directly to the SMS-GMSC.

In another embodiment, the message is submitted to the SMS-GMSC via a home subscription server (50) HSS.

In one embodiment, the message submitted to the SMS-GMSC via the HSS further comprises an instruction instructing the HSS to provide the destination address for mobility management to the SMS-GMSC.

In yet another embodiment, the notification is a non-access stratum (NAS) request received from the mobile terminal.

In a further embodiment, the notification is a context request received from a serving mobility management node of the mobile terminal, and the method further comprises: submitting a context response to the serving mobility management node comprising an indication that the SM is to be transmitted; and receiving a context acknowledgement from the serving mobility management node comprising a destination address of the serving mobility management node for SM transmission, wherein the submitted message further comprises the destination address of the serving mobility management node.

In another embodiment, the notification is a context request received from a serving mobility management node of the mobile terminal, the message being submitted to the SMS-GSMC in a context response via the serving mobility management node and further comprising a destination address of the SMS-GSMC.

In yet another embodiment, receiving the indication from the SMS-GMSC that the SM is to be transmitted includes: receiving an indication of a maximum retransmission time specifying how long the SMS-GMSC will store the SM if the SM cannot be immediately transmitted and a capability indication indicating whether the SMS-GMSC supports receiving subsequent notifications of mobile terminal availability for transmitting the SM, the method further comprising: submitting an indication to the SMS-GMSC comprising a request for retransmission time indicating at which point in time the SMS-GMSC should retransmit the SM and a capability acknowledgement indicating that the mobility management node supports the subsequent notification of mobile terminal availability for transmitting the SM.

In a further embodiment, the submitted message further indicates a time period specifying a time until the mobile terminal enters the eDRX mode again.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, device, component, means, step, etc" are to be interpreted openly as referring to at least one instance of the element, device, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

Drawings

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

fig. 1 is a prior art timing diagram illustrating MT SM delivery from SMC to MME;

fig. 2 is a timing diagram illustrating problems associated with the MT SM transfer procedure of fig. 1;

FIG. 3 illustrates one embodiment of the method of the present invention;

FIG. 4 shows another embodiment of the method of the present invention;

FIG. 5 shows a further embodiment of the method of the present invention;

FIG. 6 shows yet another embodiment of the method of the present invention;

FIG. 6 illustrates a further embodiment of the method of the present invention;

FIG. 7 shows yet a further embodiment of the method of the present invention;

FIG. 8 shows a further embodiment of the method of the present invention;

FIG. 9 shows another embodiment of the method of the present invention;

FIG. 10 shows a further embodiment of the method of the present invention;

figure 11 shows an embodiment of a mobility management node of the present invention; and

figure 12 shows a further embodiment of the mobility management node of the present invention.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout

Fig. 1 shows a timing diagram illustrating the MT SM transfer from SMSC to MME disclosed in the previous introduction "MT SMS procedures for UEs in extended idle mode DRX (MT SMS procedure of UE in extended idle mode DRX)".

Fig. 2 shows a timing diagram of the problems associated with the MT SM transfer procedure of fig. 1 previously described. The SMSC will hereinafter be referred to as the short message service gateway mobile switching center (SMS-GMSC).

In short, a first problem arises if the UE 10 wakes up from the eDRX cycle, i.e., exits the eDRX mode in which it resides, before the next paging occasion occurs. The SMS-GMSC40 has been scheduled for SM delivery of the next paging occasion and therefore missed via the MME₁/SGSN₁20 an opportunity to transmit the SM to the UE 10 exiting eDRX mode; once the next paging occasion occurs, there is a risk that the UE 10 enters eDRX mode again, resulting in another SM transmission failure and the procedure has to be repeated.

Furthermore, a second problem arises if the UE 10 exits eDRX mode in which it resides before the next paging occasion occurs, in this case referring to performing inter-MME TAU, for example. In this case, when the SMS-GMSC40 is scheduled for SM transmission of the next paging occasion, the SMS-GMSC40 does not transmit the SM to the MME₂/SGSN₂30, but instead the SM is transferred to the MME which is no longer the serving MME₁/SGSN₁ 20。

Hereinafter, MME₁/SGSN₁And MME₂/SGSN₂Will be referred to as MME respectively₁And MME₂. It should be noted, however, that they embody both the mobility management nodes of the UTRAN and the E-UTRAN.

FIG. 3 shows a method at MME₁One embodiment of the method of the present invention performed at 20 that enables the delivery of MT SM from the SMs-GMSC40 to the UE 10.

In a first step S101, the MME₁20 receive from the SMS-GMSC40 that the SM is to be delivered to the current eDRX modeThe UE 10 of (1). Now, if the UE 10 exits eDRX mode before the paging occasion occurs, e.g. as a result of NAS request or general service request for intra-MME TAU, intra-SGSN RAU, etc., the MME₁20 will receive a notification accordingly in a second step S102.

In a third step S103, the MME responds to the indication received in step S102₁The message 20 submits to the SMS-GMSC40 indicating that the UE 10 is available to transmit SM immediately. As a result, the SMS-GMSC will advantageously not miss in step S104, via the MME₁20 an opportunity to transmit the SM to the UE 10 that is not currently in eDRX mode.

In an alternative embodiment, the message is not submitted directly to the SMS-GMSC40, but via the HSS (not shown in fig. 3). In such embodiments, the message submitted to the SMS-GMSC40 via the HSS further comprises instructing the HSS to send the MME₁20 (HSS known) is provided to the SMS-GMSC40 so that the SMS-GSMC 40 can go via the MME₁20 instructions to transmit the SM to the UE 10.

Fig. 4 shows an embodiment of the method of the present invention enabling the delivery of MT SM from the SMs-GMSC40 to the UE 10.

In a first step S101, the MME₁The indication that the SM is to be transmitted to the UE 10 currently in eDRX mode is received 20 from the SMS-GMSC 40. Now, if the UE 10 exits eDRX mode before the paging occasion occurs, e.g. as being directed to MM at step S102a₂30 NAS request or general service request for TAU, RAU, or the like, and other MME₁20 will receive notifications accordingly. However, in contrast to the embodiment described with reference to fig. 3, in this case the notification is not received from the UE 10, but rather from the MME in the form of a context request at step S102b₂(now the serving MME) received.

As a result, MME₁20 submission to be made by the MME at step S102c₂30 receives and includes a context response indicating that the SM is to be transmitted. In response thereto, the MME₁20 receives at step S102d the request by the MME₂Sent and including a new serving MME (i.e., MME) for subsequent SM transfer₂30) Is determined.

In step S103, MME₁20 submit a message to the SMS-GMSC40 indicating that the UE 10 is available for immediate SM transfer in response to the notification received at step S102b, this message further including in this embodiment the MME as serving MME₂30, of the destination address.

As a result, the SMS-GMSC40 will advantageously transmit the SM to the correct MME, i.e. MME, at step S105₂30 and further to the UE 10 not currently in eDRX mode.

Referring again to fig. 4, in an alternative embodiment, the notification that the UE 10 has exited eDRX mode is again in the form of a context request from the MM at step S102b₂30. However, the message indicating that the SM can be immediately transmitted to the UE 10 is in the context response of step S102c, via MM at step S103a₂30 is submitted to the SMS-GSMC 40, which message further includes information for MM in this embodiment₂30, the destination address of the SMS-GSMC 40.

Similar to the embodiment discussed with reference to fig. 4, it is contemplated in one embodiment that the message is not submitted directly to the SMS-GMSC40, but is submitted via the HSS (not shown in fig. 4). In such embodiments, the message submitted to the SMS-GMSC40 via the HSS further includes an instruction to the HSS to submit the MM to the SMS-GMSC40₂30 to the SMS-GMSC40 so that the SMS-GSMC 40 can go via the correct MME (i.e., MM)₂30) An instruction to transmit the SM to the UE 10.

Referring to fig. 3 and 4, it is contemplated in one embodiment to employ step S101 (wherein the MME is₁20 receives an indication from the SMS-GMSC40 that the SM is to be transmitted to the UE 10 currently in eDRX mode) is extended to include steps 101a and 101b of fig. 5, which will be described below.

FIG. 5 shows a method at the MME based on the embodiments previously discussed with reference to FIG. 3₁The embodiment of the invention performed at 20 that enables the transfer of the MT SM from the SMs-GMSC40 to the UE 10.

In a first step S101a, the MME₁The indication that SM is to be transmitted to the UE 10 is received 20 from the SMS-GMSC40 in the form of a TFR, which includes a maximum retransmission time indicating that the SMS-GMSC40 cannot transmit SM immediatelyHow long to store the SM; and MME₁20 further receives a capability indication indicating whether the SMS-GMSC40 supports receiving a subsequent notification of the availability of the UE for transmitting said SM.

Thereafter, at step S101b, the MME since the UE 10 is currently in eDRX mode₁The 20 responds with TFA indicating the requested retransmission time, i.e. the time when the SM should be retransmitted by the SMs-GMSC 40. TFA further indicates that when UE 10 exits eDRX mode, MME₁Whether to support subsequent notifications for transmitting UE availability for the SM.

As already described before, if the UE 10 exits eDRX mode before a paging occasion occurs, e.g. as a result of a NAS request or a general service request for an intra-MME TAU, an intra-SGSN RAU, etc., the MME₁20 will receive a notification accordingly in a second step S102.

At step S103, in response to the indication received at step S102, the MME₁The message 20 submits to the SMS-GMSC40 indicating that the UE 10 is available to transmit SM immediately. As a result, the SMS-GMSC will advantageously not miss in step S104, via the MME₁20 an opportunity to transmit the SM to the UE 10 that is not currently in eDRX mode.

Optionally, for all embodiments of the invention, this message comprises a maximum UE availability time, i.e. a period of time specifying the time until the UE 10 enters eDRX mode again, thereby advantageously indicating a time window during which the UE 10 is available for SM transmission.

As can be seen from fig. 5, the submission in step S103 uses an existing message such as OFR or a new Diameter message. The SMS-GMSC40 acknowledges this message at step S104a using an existing message such as OFA or a new Diameter message, respectively.

The SM to be processed is transmitted by the SMS-GMSC40 in TFR of step S104, and the MME₁The transmission is accordingly confirmed by TFA at step S106.

FIG. 6 shows a method at the MME based on the embodiments previously discussed with reference to FIG. 4₁One embodiment of the invention performed at 20 that enables the transfer of MT SM from the SMs-GMSC40 to the UE 10.

In a first step S101a，MME₁Receiving 20 from the SMS-GMSC40 an indication that SM is to be transmitted to the UE 10 in the form of a TFR, the TFR including a maximum retransmission time indicating how long the SMS-GMSC40 stores the SM if it cannot transmit the SM immediately; and MME₁20 further receives a capability indication indicating whether the SMS-GMSC40 supports receiving a subsequent notification of the availability of the UE for transmitting the SM.

Thereafter, at step S101b, the MME since the UE 10 is currently in eDRX mode₁The 20 responds with TFA indicating the requested retransmission time, i.e. the time when the SM should be retransmitted by the SMs-GMSC 40. TFA further indicates that when UE 10 exits eDRX mode, MME₁Whether to support subsequent notification of UE availability for transmitting SM.

As already described before, if the UE 10 exits eDRX mode before a paging occasion occurs, e.g. as a result of a NAS request or a general service request for an intra-MME TAU, an intra-SGSN RAU, etc., the MME₁20 will receive a notification accordingly in a second step S102.

At step S103b, in response to the indication received at step S102, the MME₁The message indicating that the UE 10 is available to transmit SM immediately is submitted 20 to the SMS-GMSC40 via the HSS 50. This message may be submitted, for example, in the form of an Update Location Request (ULR) or a notify request (NOR), and includes an indication to HSS 50 to subsequently send the MME₁The destination address of 20 is provided to the SMS-GMSC40 instruction.

The HSS 50 responds accordingly with an acknowledgement in the form of, for example, an Update Location Answer (ULA) or a notification answer (NOA) at step S103c, and sends an indication of UE availability and MME availability in Alert-Service-Centre-request (alr) at step S103d₁20, address of the mobile device. The SMS-GMSC therefore sends an acknowledgement Alert-Service-Centre-answer (ala) to the HSS 50 at step S103 e.

Optionally, the messages in S103b and S103d include a maximum UE availability time, i.e. a time period specifying the time until the UE 10 enters eDRX mode again, thereby advantageously indicating a time window during which the UE 10 is available for SM transmission.

The SM to be processed is transmitted by the SMS-GMSC40 in TFR of step S104, and the MME₁The transmission is accordingly confirmed using TFA at step S106. As a result, the SMS-GMSC40 will advantageously not miss the passing through the MME at step S104₁20 an opportunity to transmit the SM to the UE 10 that is not currently in eDRX mode.

Fig. 7 shows an embodiment of the invention enabling the transfer of MT SM from the SMs-GMSC40 to the UE 10 based on the embodiment previously discussed with reference to fig. 4.

In a first step S101a, the MME₁Receiving 20 from the SMS-GMSC40 an indication that SM is to be transmitted to the UE 10 in the form of a TFR, the TFR including a maximum retransmission time indicating how long the SMS-GMSC40 stores the SM if it cannot transmit the SM immediately; and MME₁20 further receives a capability indication indicating whether the SMS-GMSC40 supports receiving a subsequent notification of the availability of the UE for transmitting the SM.

Thereafter, at step S101b, the MME since the UE 10 is currently in eDRX mode₁The 20 responds with TFA indicating the requested retransmission time, i.e. the time when the SM should be retransmitted by the SMs-GMSC 40. TFA further indicates that when UE 10 exits eDRX mode, MME₁Whether to support subsequent notification of UE availability for transmitting SM.

If the UE 10 exits eDRX mode before the paging occasion occurs, e.g., as being directed to MM at step S102a₂30 NAS request or general service request for TAU or RAU, and the MME₁20 will accordingly request from the MME in the form of a context request at step S102b₂The notification is received 30 (now the serving MME).

As a result, MME₁20 to MME at step S102c₂30 submit a context response comprising an indication that the SM is to be transmitted, which message further comprises, in this embodiment, a context response for the MM₂30, the destination address of the SMS-GSMC 40. In response thereto, the MME₂30 towards the MME in step S102d₁20 sends a context acknowledgement.

At step S103a, in response to the indication received at step S102c, the MME₂30 submit a message to the SMS-GMSC40 indicating that the UE 10 is available to transmit SM immediately. As a result, the SMS-GMSC40 will advantageously transmit the SM to the correct MME, i.e. MME, at step S105₂30 and further to the UE 10 not currently in eDRX mode.

Optionally, this message includes a maximum UE availability time, i.e. a period of time that specifies the time until the UE 10 enters eDRX mode again, thereby advantageously indicating a window of time during which the UE 10 is available for SM transmission.

As can be seen from fig. 7, the submission in step S103 uses an existing message such as OFR or a new Diameter message. The SMS-GMSC40 acknowledges this message at step S105a using an existing message such as OFA or a new Diameter message, respectively.

The SM to be processed is transmitted by the SMS-GMSC40 in the TFR of step S105, and the MME₂30 accordingly confirms the transfer using TFA at step S106 a.

Fig. 8 shows an embodiment of the invention enabling the transfer of MT SM from the SMs-GMSC40 to the UE 10 in relation to the embodiment previously discussed with reference to fig. 7.

However, in this particular embodiment, the message indicating that the UE is available for SM delivery is by the MM₂30 are sent to the SMS-GSMC 40 via the HSS 50.

In a first step S101a, the MME₁Receiving 20 from the SMS-GMSC40 an indication that SM is to be transmitted to the UE 10 in the form of a TFR, the TFR including a maximum retransmission time indicating how long the SMS-GMSC40 stores the SM if it cannot transmit the SM immediately; and MME₁20 further receives a capability indication indicating whether the SMS-GMSC40 supports receiving a subsequent notification of the availability of the UE for transmitting the SM.

Thereafter, at step S101b, the MME since the UE 10 is currently in eDRX mode₁The 20 responds with TFA indicating the requested retransmission time, i.e. the time when the SM should be retransmitted by the SMs-GMSC 40. TFA further indicates that when UE 10 exits eDRX mode, MME₁Whether to support subsequent notification of UE availability for transmitting SM.

If the UE 10 exits eDRX mode before the paging occasion occurs, e.g., as being directed to MM at step S102a₂30 NAS request or general service request for TAU or RAU, and the MME₁20 will accordingly in step S102bFrom MME in the form of a context request₂The notification is received 30 (now the serving MME).

As a result, MME₁20 to MME at step S102c₂30 submit a context response comprising an indication that the SM is to be transmitted, which message further comprises, in this embodiment, a context response for the MM₂30, the destination address of the SMS-GSMC 40. In response thereto, the MME₂30 towards the MME in step S102d₁20 sends a context acknowledgement.

In step S103f, in response to the indication received in step S102c, the MM is₂30 submit a message to the SMS-GMSC40 via the HSS 50 indicating that the UE 10 is available to transmit the SM immediately. This message may be submitted, for example, in the form of an ULR or NOR, and include an instruction to the HSS 50 to subsequently submit the MM₂30 to the SMS-GMSC 40.

The HSS 50 responds accordingly by an acknowledgement in the form of, for example, ULA or NOA at step S103g, and sends an indication of UE availability and MM in ALR at step S103h₂30, of the address of the mobile device. The SMS-GMSC40 therefore sends an acknowledgement (ALA) to the HSS 50 at step S103 i.

Optionally, the messages in steps S103f and S103h include a maximum UE availability time, i.e. a time period specifying the time until the UE 10 enters eDRX mode again, thereby advantageously indicating a time window during which the UE 10 is available for SM transmission.

The SMS-GMSC40 will advantageously transmit the SM to the correct MME, i.e. MME, at step S105₂30, and further to the UE 10 not currently in eDRX mode, and MME₂30 accordingly confirms the transfer using TFA at step S106 a.

Fig. 9 shows an embodiment of the invention enabling the transfer of MT SM from the SMs-GMSC40 to the UE 10 based on the embodiment previously discussed with reference to fig. 4.

In a first step S101a, the MME₁The indication that the SM is to be transmitted to the UE 10 is received 20 from the SMS-GMSC 40. Preferably, the indication takes the form of a TFR that includes a maximum retransmission time that indicates how long the SMS-GMSC40 will store the SM if it cannot be transmitted immediately. The indication may be furtherA capability indication is included that indicates whether the SMS-GMSC40 supports receiving a subsequent notification of the availability of the UE for transmitting the SM.

Thereafter, at step S101b, the MME since the UE 10 is currently in eDRX mode₁The SMS-GMSC40 is preferably responded to with TFA indicating the requested retransmission time, i.e. the time when the SM should be retransmitted by the SMS-GMSC 40. TFA may further indicate that when the UE 10 exits eDRX mode, the MME₁Whether to support subsequent notification of UE availability for transmitting SM.

If the UE 10 exits eDRX mode before the paging occasion occurs, e.g., as being directed to MM at step S102a₂30 NAS request or general service request for TAU, RAU, or the like, and other MME₁20 will accordingly request from the MME in the form of a context request at step S102b₂The notification is received 30 (now the serving MME).

As a result, MME₁20 to MME at step S102c₂30 submit a context response including SM to be MME₂30 received. In response thereto, the MME₂30 towards the MME in step S102d₁20 sending includes MME₂30, context validation of the destination address.

In step S103, MME₁20 submitting to SMS-GMSC40 indicates that UE 10 is available for immediate SM transfer and includes MME₂30, destination address of the mobile device. As a result, the SMS-GMSC40 will advantageously transmit the SM to the correct MME, i.e. MME, at step S104₂30 and further to the UE 10 not currently in eDRX mode.

Optionally, this message includes a maximum UE availability time, i.e. a period of time that specifies the time until the UE 10 enters eDRX mode again, thereby advantageously indicating a window of time during which the UE 10 is available for SM transmission.

As can be seen from fig. 9, the submission in step S103 uses an existing message such as OFR or a new Diameter message. The SMS-GMSC40 acknowledges this message at step S104a using an existing message such as OFA or a new Diameter message, respectively.

The SM to be processed is processed by the SMS-GMSC40 in the TFR of step S105Transmitting and MME₁The transfer is accordingly confirmed using TFA at step S106 a.

Fig. 10 shows an embodiment of the invention enabling the transfer of MT SM from the SMs-GMSC40 to the UE 10 in relation to the embodiment previously discussed with reference to fig. 9.

However, in this particular embodiment, the message indicating that the UE is available for SM delivery is by the MM₁20 are sent to the SMS-GSMC 40 via the HSS 50.

In a first step S101a, the MME₁Receiving 20 an indication from the SMS-GMSC40 that the SM is to be transmitted to the UE 10 in the form of a TFR, the TFR including a maximum retransmission time indicating how long the SMS-GMSC40 stores the SM if it cannot be transmitted immediately; and MME₁20 further receives a capability indication indicating whether the SMS-GMSC40 supports receiving a subsequent notification of the availability of the UE for transmitting the SM.

Thereafter, at step S101b, the MME since the UE 10 is currently in eDRX mode₁The 20 responds with TFA indicating the requested retransmission time, i.e. the time when the SM should be retransmitted by the SMs-GMSC 40. TFA further indicates that when UE 10 exits eDRX mode, MME₁Whether to support subsequent notification of UE availability for transmitting SM.

If the UE 10 exits eDRX mode before the paging occasion occurs, e.g., as being directed to MM at step S102a₂30 NAS request or general service request for TAU or RAU, and the MME₁20 will accordingly request from the MME in the form of a context request at step S102b₂The notification is received 30 (now the serving MME).

As a result, MME₁20 to MME at step S102c₂30 submit a context response comprising an indication that the SM is to be transmitted, in response to which the MME is to transmit₂30 towards the MME in step S102d₁20 sending includes MME₂30, context validation of the destination address.

In step S103b, MM₂30 submit a message to the SMS-GMSC40 via the HSS 50 indicating that the UE 10 is available to transmit the SM immediately. This message may be submitted, for example, in the form of an ULR or NOR, and include an instruction to the HSS 50 to subsequently submit the MM₂30 destination addressInstructions provided to the SMS-GMSC 40.

The HSS 50 responds accordingly by an acknowledgement in the form of, for example, ULA or NOA at step S103c, and sends an indication of UE availability and MM in ALR at step S103h₂30, of the address of the mobile device. The SMS-GMSC40 therefore sends an acknowledgement (ALA) to the HSS 50 at step S103 e.

Optionally, the messages in steps S103b and S103c include a maximum UE availability time, i.e. a time period specifying the time until the UE 10 enters eDRX mode again, thereby advantageously indicating a time window during which the UE 10 is available for SM transmission.

The SMS-GMSC40 will advantageously transmit the SM to the correct MME, i.e. MME, at step S105₂30, and further to the UE 10 not currently in eDRX mode, and MME₂30 accordingly confirms the transfer using TFA at step S106 a.

With reference to fig. 11, the steps of the method performed by the mobility management node 20, 30 according to an embodiment of the present invention are actually performed by a processing unit 21, 31, said processing unit 21, 31 being embodied in the form of one or more microprocessors arranged to execute a computer program 22, 32 downloaded to a suitable storage medium 23, 33 associated with the microprocessor, such as a Random Access Memory (RAM), flash memory or hard disk drive. The processing unit 21, 31 is arranged to cause the computing device 20, 30 to perform a method according to an embodiment of the invention when a suitable computer program 22, 32 comprising computer executable instructions is downloaded to the storage medium 23, 33 and executed by the processing unit 21, 31. The storage medium 23, 33 may also be a computer program product comprising the computer program 22, 32. Alternatively, the computer program 22, 32 may be transferred to the storage medium 23, 33 by means of a suitable computer program product, such as a Digital Versatile Disc (DVD) or a memory stick. As a further alternative, the computer program 22, 32 may be downloaded to the storage medium 23, 33 via a network. Alternatively, the processing units 21, 31 may be embodied in the form of Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Complex Programmable Logic Devices (CPLDs), or the like.

Fig. 12 shows a first mobility management node 20 configured to enable delivery of an MT SM to a mobile terminal according to an embodiment of the present invention. The mobility management node 20 comprises receiving means 24 adapted to receive an indication from the SMS-GMSC that said SM is to be transmitted; receiving means 25 adapted to receive a notification that the mobile terminal has exited eDRX mode before the paging occasion occurred; and submitting means 26 adapted to submit, in response to said notification, a message indicating to the SMS-GMSC that said mobile terminal is available for transmission by said SM.

The devices 24 to 26 may comprise a communication interface for receiving and providing information, and further comprise a local memory for storing data, and may (similar to the description given in connection with fig. 11) be implemented by a processor embodied in the form of one or more microprocessors arranged to execute computer programs downloaded to a suitable storage medium associated with the microprocessor, such as RAM, flash memory or a hard disk drive.

Fig. 12 shows a second mobility management node 30 configured to enable delivery of an MT SM to a mobile terminal according to an embodiment of the present invention. The mobility management node 30 comprises receiving means 34 adapted to receive a notification that the mobile terminal has exited eDRX mode before the paging occasion occurred; submitting means 35 adapted to submit a context request to another mobility management node serving the mobile terminal before the notification is received; receiving means 36 adapted to receive a context response from the further mobility management node comprising an indication that the SM is to be transmitted and a destination address of the SMs-GMSC transmitting the SM; and submitting means 37 adapted to submit a message indicating to the SMS-GMSC that said mobile terminal is available for sending said SM, in response to said context response.

The devices 34 to 37 may comprise a communication interface for receiving and providing information, and further comprise a local memory for storing data, and may (similar to the description given in connection with fig. 11) be implemented by a processor embodied in the form of one or more microprocessors arranged to execute computer programs downloaded to a suitable storage medium associated with the microprocessor, such as a RAM, flash memory or hard drive.

Some of the embodiments described above may be summarized in the following manner:

a first embodiment relates to a method of a mobility management node to enable delivery of a Mobile Terminated (MT) Short Message (SM) to a mobile terminal currently in extended idle mode discontinuous reception (eDRX) mode.

The method comprises the following steps:

receiving an indication from a short message service gateway mobile switching center (SMS-GMSC) that the SM is to be delivered;

receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs; and

in response to the notification, submitting a message indicating to the SMS-GMSC that the mobile terminal is available for transmission by the SM.

The message may be submitted directly to the SMS-GMSC.

The message may be submitted to the SMS-GMSC via a Home Subscription Server (HSS).

The message submitted to the SMS-GMSC via the HSS further includes an instruction instructing the HSS to provide the destination address for mobility management to the SMS-GMSC.

The notification may be a non-access stratum (NAS) request received from the mobile terminal.

May further include: receiving the SM from the SMS-GMSC for transmission to the mobile terminal.

The notification may be a context request received from a serving mobility management node of the mobile terminal, the method may further comprise: submitting a context response to the serving mobility management node comprising an indication that the SM is to be transmitted; and receiving a context acknowledgement from the serving mobility management node comprising a destination address of the serving mobility management node for SM transmission, wherein the submitted message further comprises the destination address of the serving mobility management node.

The notification may be a context request received from a serving mobility management node of the mobile terminal, the message being submitted to the SMS-GSMC in a context response via the serving mobility management node and further comprising a destination address of the SMS-GSMC.

Receiving an indication from the SMS-GMSC that the SM is to be delivered may include:

receiving an indication of a maximum retransmission time specifying how long the SMS-GMSC will store the SM if the SM cannot be immediately transmitted and a capability indication indicating whether the SMS-GMSC supports receiving subsequent notifications of mobile terminal availability for transmitting the SM; and the method further comprises:

submitting an indication to the SMS-GMSC comprising a request for retransmission time indicating at which point in time the SMS-GMSC should retransmit the SM and a capability acknowledgement indicating that the mobility management node supports the subsequent notification of mobile terminal availability for transmitting the SM.

A second embodiment relates to a method of a mobility management node to enable delivery of a Mobile Terminated (MT) Short Message (SM) to a mobile terminal currently in extended idle mode discontinuous reception (eDRX) mode.

The method comprises the following steps:

receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs;

submitting a context request to another mobility management node serving the mobile terminal before the notification is received;

receiving a context response from the other mobility management node comprising an indication that the SM is to be transmitted; and

receiving the SM from the SMS-GMSC for transmission to the mobile terminal.

The message may be submitted directly to the SMS-GMSC.

The message may be submitted to the SMS-GMSC via a Home Subscription Server (HSS), the message submitted to the SMS-GMSC via the HSS further comprising an instruction to instruct the HSS to provide the destination address for mobility management to the SMS-GMSC.

The submitted message further indicates a time period specifying a time until the mobile terminal enters the eDRX mode again.

Another embodiment relates to a mobility management node configured to enable delivery of a Mobile Terminated (MT) Short Message (SM) to a mobile terminal currently in an extended idle mode discontinuous reception (eDRX) mode, and comprising a processing unit and a memory, the memory containing instructions executable by the processing unit whereby the mobility management node is operative to:

receiving an indication from a short message service gateway mobile switching center (SMS-GMSC) that the SM is to be delivered;

receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs; and

in response to the notification, submitting a message indicating to the SMS-GMSC that the mobile terminal is available for transmission by the SM.

The mobility management node is operable to submit the message directly to the SMS-GMSC.

The mobility management node is operable to submit the message to the SMS-GMSC via a Home Subscription Server (HSS).

The mobility management node is further operable to include in the message submitted to the SMS-GMSC via the HSS an instruction instructing the HSS to provide the destination address for mobility management to the SMS-GMSC.

The notification may be a non-access stratum (NAS) request received from the mobile terminal.

The notification may be a context request received from a serving mobility management node of the mobile terminal, the mobility management node further operable to:

submitting a context response to the serving mobility management node comprising an indication that the SM is to be transmitted; and

receiving, from the serving mobility management node, a context acknowledgement comprising a destination address of the serving mobility management node for SM transfer, wherein the submitted message further comprises the destination address of the serving mobility management node.

The notification may be a context request received from a serving mobility management node of the mobile terminal, the mobility management node being further operable to submit the message in a context response to the SMS-GSMC via the serving mobility management node, and further operable to include a destination address of the SMS-GSMC.

The mobility management node is further operable, upon receiving an indication from the SMS-GMSC that the SM is to be delivered:

receiving an indication of a maximum retransmission time specifying how long the SMS-GMSC will store the SM if the SM cannot be immediately transmitted and a capability indication indicating whether the SMS-GMSC supports receiving subsequent notifications of mobile terminal availability for transmitting the SM; and the method further comprises:

submitting an indication to the SMS-GMSC comprising a request for retransmission time indicating at which point in time the SMS-GMSC should retransmit the SM and a capability acknowledgement indicating that the mobility management node supports the subsequent notification of mobile terminal availability for transmitting the SM.

Another embodiment relates to a mobility management node configured to enable delivery of a Mobile Terminated (MT) Short Message (SM) to a mobile terminal currently in an extended idle mode discontinuous reception (eDRX) mode, and comprising a processing unit and a memory, the memory containing instructions executable by the processing unit whereby the mobility management node is operative to:

receiving a notification that the mobile terminal has exited the eDRX mode before a paging occasion occurs;

submitting a context request to another mobility management node serving the mobile terminal before the notification is received;

receiving a context response from the other mobility management node comprising an indication that the SM is to be transmitted; and

receiving the SM from the SMS-GMSC for transmission to the mobile terminal.

The mobility management node may be further operable to submit the message directly to the SMS-GMSC.

The mobility management node may be further operable to submit the message to the SMS-GMSC via a Home Subscription Server (HSS), the message submitted to the SMS-GMSC via the HSS further comprising an instruction instructing the HSS to provide a destination address for the mobility management to the SMS-GMSC.

The mobility management node may be further operable to include in the submitted message a time period specifying a time until the mobile terminal enters the eDRX mode again.

Another embodiment relates to a first computer program comprising computer executable instructions which, when executed on a processing unit comprised in a device, cause the device to perform the steps listed in the first embodiment.

Another embodiment relates to a computer program product comprising a computer readable medium having said first computer program embodied thereon.

Another embodiment relates to a second computer program comprising computer executable instructions which, when executed on a processing unit comprised in a device, cause the device to perform the steps listed in the second embodiment above.

Another embodiment relates to a computer program product comprising a computer readable medium having said second computer program embodied thereon.

The invention has mainly been described above with reference to a few embodiments. However, a person skilled in the art will readily appreciate that other embodiments than the ones disclosed above are equally possible within the scope of the invention, as defined by the appended patent claims.