WO2014068143A1

WO2014068143A1 - Method for delivering a message to a group of devices via a mobile network and mobile network

Info

Publication number: WO2014068143A1
Application number: PCT/EP2013/073059
Authority: WO
Inventors: Andreas Kunz; JaeSeung SONG; Genadi Velev
Original assignee: Nec Europe Ltd.
Priority date: 2012-11-05
Filing date: 2013-11-05
Publication date: 2014-05-08

Abstract

A method for delivering a message to a group of devices via a mobile network (1) is characterized in the steps of assigning said group of devices a group identifier, forwarding said message to a dedicated node within said mobile core network, and, at said dedicated node, acquiring binding information for resolving said group identifier into individual identifiers of the member devices (2) of said group of devices, and transmitting said message to the member devices (2) of said group of devices by using said individual identifiers. Furthermore, a mobile network (1) with a mechanism for delivering a message to a group of devices is disclosed.

Description

METHOD FOR DELIVERING A MESSAGE TO A GROUP OF DEVICES VIA A MOBILE NETWORK AND MOBILE NETWORK

The present invention relates to a method for delivering a message to a group of devices via a mobile network.

Furthermore, the present invention relates to a mobile network with a mechanism for delivering a message to a group of devices. In today's communication scenarios, there are various situations or applications in which one and the same message has to be delivered to a number of devices. Depending on the specific application, the group of recipients may include hundreds or even thousands of devices. In particular, although not limited to, such scenarios occur in the field of MTC (Machine Type Communication) applications. For instance, to name just one particular application, one can think of energy suppliers who want to trigger the electricity meters of their customers to transmit a particular parameter, e.g. the current energy value of the meters.

Currently there is no solution to provide a message to a small group of MTC devices without severe changes to the current network architecture described in 3GPP TS 23.682 "Architecture enhancements to facilitate communications with packet data networks and applications". Current solutions only describe the delivery of group messages via cell broadcast or multicast. These methods have several severe issues to solve, e.g. related to security or to the mapping of identifiers, which is only possible in a limited geographic region. While these methods are suitable to provide group messages to a group with a huge amount of members, sometimes the groups may have only a limited number of member devices which, in addition, may be geographically distributed or even moving within the geographic region. For those groups the mentioned solutions are not suitable.

In view of the above it is an objective of the present invention to improve and further develop a method for delivering a message to a group of devices via a mobile network and a mobile network in such a way that a higher degree of flexibility regarding the composition of the recipients of the message is achieved.

In accordance with the invention, the aforementioned object is accomplished by a method comprising the features of claim 1. According to this claim such a method is characterized in the steps of

assigning said group of devices a group identifier,

forwarding said message to a dedicated node within said mobile core network,

at said dedicated node, acquiring binding information for resolving said group identifier into individual identifiers of the member devices of said group of devices, and transmitting said message to the member devices of said group of devices by using said individual identifiers. Furthermore, the above mentioned objective is accomplished by a mobile network comprising the features of claim 18. According to this claim such a mobile network is characterized in that it comprises a dedicated node within the mobile core network that is configured

to acquire binding information for resolving a group identifier assigned to said group of devices into individual identifiers of the member devices of said group of devices, and

to transmit said message to the member devices of said group of devices by using said individual identifiers. According to the present invention it has been recognized that a higher degree of flexibility regarding the composition of the recipients of the message can be achieved when the message is first forwarded within the mobile core network as a group message by using an internal routable group identifier (instead of sending individual messages from the beginning, i.e. from the originator of the message) and when the group identifier is then resolved by a dedicated node within the mobile core network, e.g. by the last node that is keeping the state of the message delivery. By retrieving the individual identifiers of the member devices of the group of devices, an individual transmission of the message to the member devices is enabled. The present invention is therefore most beneficial for small groups of devices where the reliability of message delivery needs to be tracked. It is beneficial when all member devices of a group are served by the same control plane node, e.g. MME. According to an embodiment of the invention the dedicated node may be a serving node in the mobile core network the member devices of the group of devices are associated with. In particular, in case of 3GPP networks, the serving node may be an MME (Mobility Management Entity), an MSC (Mobile-services Switching Centre), or an SGSN (Serving GPRS Support Node). In case of SMS related application scenarios, the dedicated node may be an SMS-SC (Short Message Service - Service Centre). As will be easily appreciated by those skilled in the art, the above list is not conclusive, and in mobile networks other than 3GPP networks different nodes may be configured to function as dedicated node for resolving a group identifier into individual identifiers of the member devices and for transmitting the message to the member devices by using the individual member identifiers. In an alternative embodiment it may be an MTC-IWF (MTC Interworking Function) implemented in the mobile core network that implements the functionality of the dedicated node. According to a preferred embodiment the member devices of the group of devices may be MTC devices, since the present invention can be most suitably applied in MTC type communication scenarios. In such applications, the message may be generated by or may originate from an MTC application server. Further in such applications, the message may be a trigger message for the member devices of the group of devices to perform a specific action. For instance, an MTC application server of an energy provider may generate a message that triggers the electric meters of the energy provider's customers to transmit their current meter readings.

According to an alternative embodiment the present invention may be applied to Group Communication related to the ongoing work on Group Communication Service Enabler (GCSE) as documented in 3GPP TR 23.768. In this case it may be a GCSE application server that implements the functionality of the dedicated node. ln any case, i.e. independent of whether the invention is applied in MTC scenarios with the dedicated node being an MTC application server or whether the invention is applied in a Group Communication related context with the dedicated node being an GCSE application server, it may be provided that the dedicated node transmits the message to the member devices of the group of devices by means of individual transmissions. Individual transmissions come along with the advantage that it is possible to reach also member devices of the same group of devices that are served by the same serving node as dedicated node, even though they do not belong to the same geographical area, e.g. cell. This is advantageous compared to solutions that rely on cell broadcast or multicasts services for the delivery of the message. In addition, sending the message via individual transmissions to the member devices of a group of devices enables the dedicated node that keeps state of the message delivery to resend the message only to those member devices of the group of devices that have not received the message correctly in the first try.

In an alternative or hybrid embodiment, the dedicated node may transmit the message to the member devices of the group of devices by means of multicast transmissions. For instance, in case of applications in a Group Communication related context as described above, the GCSE application server typically has the additional knowledge of the location of the member device of a group of devices and the selected multicast area so that it can provide multicast services for the member devices within the coverage of such service and individual transmission for those member devices of the group of devices outside of the multicast area.

With respect to an efficient creation of the group identifier used for addressing the group of devices, it may be provided that the group identifier is created as a group MSISDN (Mobile Station Integrated Services Digital Network Number) or a group IMSI (International Mobile Subscriber Identity). For instance, a group MSISDN or a group IMSI could be easily derived from the MSISDNs or IMSIs of the member devices of the respective group, e.g. according to a predefined algorithm. Alternatively, the group identifier may be created as a group URI or as a group E.164 number (as specified by ITU-T). Generally, in this context it is important to note that the above group identifier is an "internal" group identifier, which is routable within the mobile network. This "internal" group identifier has to be distinguished from an "external" group identifier, which the originating node of the message outside the mobile network, e.g. an MTC application server of an energy supplier, may use to identify the addressed devices. As will be easily appreciated by those skilled in the art, there are various possibilities how to translate such external identifier into an internal, routable identifier for the mobile network.

According to one embodiment, in a 3GPP scenario, the dedicated node may acquire binding information that consists of the internal group identifier and the internal identifiers of the group member devices, e.g. IMSI or MSISDN, from the HSS (Home Subscriber Server). In this regard it may be provided that the group membership information per device is stored or preconfigured in the HSS.

According to an alternative embodiment, which is beneficial in terms of avoiding overload in the HSS, the dedicated node may store a relation (i.e. a kind of binding) of the individual identifiers of the member devices of the group of devices and the group identifier. Advantageously, the dedicated node is informed of group memberships at the time devices attach to the mobile network. In particular scenarios it may happen that the member devices of a group of devices are attached to different serving nodes. In such cases, it may be provided that the message is forwarded to all involved serving nodes.

There are several ways how to design and further develop the teaching of the present invention in an advantageous way. To this end it is to be referred to the patent claims subordinate to patent claims 1 and 18 on the one hand and to the following explanation of preferred embodiments of the invention by way of example, illustrated by the drawing on the other hand. In connection with the explanation of the preferred embodiments of the invention by the aid of the drawing, generally preferred embodiments and further developments of the teaching will be explained. In the drawing Fig. 1 is a schematic view illustrating an application scenario in a 3GPP architecture for machine type communication in accordance with an embodiment of the invention,

Fig. 2 is a flow diagram illustrating a group triggering call flow in accordance with an embodiment of the invention, and

Fig. 3 is a schematic view illustrating an application scenario in a GCSE architecture in accordance with an embodiment of the invention.

Fig. 1 schematically illustrates a mobile network 1 according to the 3GPP architecture for the support of machine type communication (MTC) from 3GPP TS 23.682 "Architecture enhancements to facilitate communications with packet data networks and applications". Currently the architecture according to this standard supports three different ways, how an MTC device 2 can be triggered by way of a trigger message to perform a specific action. The trigger message payload itself is transparent to the 3GPP system.

The MTC application server (AS) 3 sends a trigger either directly or indirectly or in a hybrid mode that combines elements of the direct and of the indirect approach. In the direct mode, the MTC application server 3 is aware of the IP address of the MTC device 2 and can send a trigger message via the user plane connection, i.e. via the Gi/SGi reference point.

In the indirect model, the MTC application server 3 sends the trigger message via a Service Capability Server (SCS) 4, which belongs either to the mobile network 1 or the MTC service provider that hosts the MTC application server 3. The SCS 4 then provides the trigger message to the MTC interworking function (IWF) 5, which can translate the external identity of the MTC device 2 into an internal, routable identity for the mobile network 1 and which decides whether the trigger is sent via the T4 or the T5 interface to the MTC device 2. According to the above trigger mechanisms, for each MTC device 2 to be triggered, an individual trigger message has to be transmitted from the MTC application server 3 to the respective MTC device 2, which produces a large amount of signaling traffic within the mobile network 1. In connection with the flow diagram of Fig. 2, which builds upon the architecture shown in Fig. 1 , an embodiment of the present invention is described hereinafter that reuses the current trigger mechanisms described in 3GPP TS 23.682 and that modifies the procedures in order to take also group messaging into account. It is noted that while the embodiment of Fig. 2 relates to MTC type communication, the method according to the present invention can likewise be applied to "normal" UEs that are not specialized for MTC service.

Referring now to Fig. 2, in step 1 the binding between an external group ID (the MTC application server 3 has used to identify a group of MTC devices that are intended to be addressed by the trigger message) and the MTC UE group members 2 is performed. For simplicity, in the illustrated embodiment is assumed that the external group ID is preconfigured in the subscription information of the MTC UEs 2, i.e. the MTC Service provider is aware which MTC UE 2 is belonging to which group and has which external group ID. As will be easily appreciated by those skilled in the art it is also possible to have the binding information in other nodes.

In step 2, the MTC application server 3 sends a trigger message to the group of MTC devices 2 using the external group ID.

As illustrated in step 3, when this trigger message is received at the MTC-IWF 5, the MTC-IWF 5 performs authorization and load control and requests from the HSS 6 subscriber information how to resolve the external group ID to an internal group ID, such as Group MSISDN or Group IMSI. Then, the MTC-IWF 5 would select the method how to deliver the trigger message, e.g. via T4 or T5, and it forwards the trigger message to the respective nodes using the internal group ID.

Depending on the trigger delivery method, e.g. T4 or T5, in step 4, the MSC 7, MME 8, SGSN 9 or SMS-SC 10 would receive the trigger message. The node that received the trigger message and is keeping state of the delivery of the trigger message (i.e. MSC 7, MME 8, SGSN 9 or SMS-SC 10) is now, in step 5, requesting the binding information from the HSS 6 in order to know which individual MTC group members 2 have to be triggered independently. The binding information consists of the internal identifiers of the group members, e.g. IMSI, MSISDN, and of the internal group ID. The MSC 7, MME 8, SGSN 9 or SMS-SC 10 creates individual trigger messages to the IMSI/MSISDN of each MTC UE 2 of the group.

In step 6, the MSC 7, MME 8, SGSN 9 or SMS-SC 10 sends the trigger messages to all MTC UEs 2 in the group individually. This has the benefit that also MTC UEs 2 of the same group under the same MME 8 can be easily triggered, even they do not belong to the same geographical area, e.g. cell. This is an advantage in comparison to solution using cell broadcast or multicast services.

Finally, in step 7, the MTC UEs 2 send back to the MTC application server 6 the requested action from the payload of the trigger message. The answer of the MTC devices 2 to the MTC application server 6 is transparent to the 3GPP network. Sending individual messages to the MTC UEs 2 has also the advantage that it is easier for the nodes that are keeping state for the message delivery to track whether a message is received correctly or not. It would be possible to retry only for such MTC UEs 2 that do not have received the message correctly and it is not needed to send it again to all MTC UEs 2.

In connection with the above embodiment it is assumed so far that all MTC UEs 2 that belong to the same group (group members) are served by the same serving node, i.e. MSC 7, MME 8, SGSN 9, SMS-SC 10, or the like. Due to geographic distribution of the devices 2 it is possible though that the group members are served by more than one serving node. With other words, the group members are attached to multiple serving nodes in case of message delivery over T5 interface, e.g. including T5a, T5b and T5c interfaces as depicted in Fig. 1 (but also other interfaces that may be specified in the future). In this case the HSS 6 query response to the MTC-IWF 5 in step 3 of Fig. 2 would contain a list of the involved serving nodes. In step 4 of Fig. 2, the MTC-IWF 5 would then send individual messages to all involved serving nodes. For this purpose the MTC-IWF 5 could implement functionality for multiplying one incoming message to multiple outgoing messages to multiple serving nodes over the T5 interface.

In yet another alternative to step 3 from Fig. 2, the membership information per device may be stored or preconfigured in the HSS 6. This membership information can be provided to the HSS 6 as described in step 1 of Fig. 2, by e.g. an Application Server or any other database. During step 3, the response from the HSS 6 to the MTC-IWF 5 contains a list of individual internal identifiers of the group member UEs 2 corresponding to the external group identifier that has been used in the request to the HSS 6. Additionally, the response from the HSS 6 to the MTC-IWF 5 can contain the current serving node identifier, to which the individual group member 2 is registered. Thus, this response from the HSS 6 to MTC-IWF 5 is a kind of bulk signaling, i.e. one single message contains a list of information for multiple (or even all) members of a group corresponding to the external group identifier. Then in step 4 from Fig. 2, the MTC-IWF 5 generates and sends a group message to the serving nodes where the group members 2 are registered, wherein the group message contains a list of the individual internal identifiers of the UEs registered at the particular serving node. With other words, the group message from MTC-IWF 5 to the serving nodes is a kind of bulk message containing the individual identifiers of the target group members 2. After receiving this group message, the serving node does not need to query the HSS 6, but instead the serving node generates individual messages to all group member UEs 2 contained in the list of identifiers in the group message. Then the serving node performs step 6 from Fig. 2 to deliver the individual messages to the corresponding UEs 2.

In connection with step 5 from Fig. 2, it has been described above that the serving node (e.g. MCS 7, MME 8, SGSN 9 or SMS-SC 10) requests the resolution of the group internal identifier (group MSISDN or group IMSI) to individual group member UEs 2 by requesting the HSS 6. One problem of this approach is that the requests from the serving nodes to the HSS 6 may cause overload in the HSS 6. Therefore, an alternative embodiment to step 5 from Fig. 2 is that the serving node stores a relation (i.e. a kind of binding) of the UE unique internal identifier (MSISDN or I MSI) and the internal group identifier used in the (group) message from MTC-IWF 5 to the serving node. The serving nodes may already learn the group memberships of a device at the time of the UE attach procedure to the mobile network 1 or when the serving node is chosen, e.g. based on mobility management related procedures.

Another option for the serving node to learn the membership information per device is to receive this information from the HSS 6. For example, the membership information may be included in the Subscriber Profile which is downloaded to the serving node at time of attach or at time of serving node reallocation procedure. The serving node is then able to create a binding ad hoc and learn continuously which devices belong to which group. In this case, step 5 of Fig. 2 is not needed. With other words, when the serving node receives the message containing the group internal identifier from the MTC-IWF 5, the serving node performs an internal search in the UEs contexts to find out which UEs contexts contain the internal group identifier, i.e. which UEs are members of the group corresponding to the internal group identifier. Then the serving node continues with step 6 from Fig. 2 to deliver the (group) message as individual message to all UEs 2 which have been identified as members of the internal group identifier.

Fig. 3, in which same reference numerals denote same components as in Figs. 1 and 2, relates to an embodiment of the present invention applied in a GCSE (Group Communication Service Enabler) architecture, as documented in 3GPP TR 23.768 "Study on architecture enhancements to support Group Communication System Enablers for LTE (GCSE_LTE)". Specifically, Fig. 3 illustrates the high- level architecture of GCSE with the main elements being the GCSE Application Server (GCSE AS) 11 and the connection to the Broadcast/Multicast technology 12, e.g. MBMS (Multimedia Broadcast Multicast Service) or CBS (Cell Broadcast Service). As will be appreciated by the skilled artisan, the architecture of Fig 3 is not limited to MBMS and LTE as described in 3GPP TR 23,768, but it also covers the case MBMS in UMTS and GSM. The GCSE AS 1 1 would connect to the BMSC (Broadcast Multicast Service Centre) 12 with the GC2 reference point. The incoming messages (from individual UE or a dispatcher) to a group of UEs are received at the GCSE AS 1 1. The type of message may be of different media, e.g. text, voice, video, data file etc. The GCSE AS 1 1 takes the decision how to distribute the message either point to point or via point to multipoint technologies. The GCSE AS 1 1 has the binding of UEs to groups. Insofar, the GCSE AS 1 1 corresponds to the serving node Figs. 1 and 2, which is resolving the group address to individual group members and distributes the message accordingly. Individual messages are sent via the SGi interface. In addition to the embodiment described in Fig. 2, the GCSE AS 11 has the additional knowledge of the location of the UEs and the selected multicast area so that it can provide multicast services for the UEs within the coverage of such service and individual transmission for those UEs in the group outside of the multicast area.

In another embodiment the MTC and GCSE features may be combined, i.e. the GCSE-AS 1 1 delivers the group message to the MTC-IWF 5 (not shown in Fig. 3). The MTC-IWF 5 is able to utilize also multicast message or trigger delivery and is directly or indirectly connected to the BMSC 12. The MTC-IWF 5 in that case holds the relevant functionality in order to decide which UEs are registered and have joined the MBMS group. The UEs which have joined the MBMS group are able to receive the message via multicast and MTC-IWF 5 can send the group message to the BMSC 12. Other group member UEs, which are not registered or have not joined the MBMS group, need to be addressed as a group or individually via the corresponding serving node, e.g. MSC 7, MME 8, SGSN 9, SMS-SC 10, etc. With other words, the MTC-IWF 5 is able to determine which of the group members have joined the MBMS group and are reachable over the MBMS.

Many modifications and other embodiments of the invention set forth herein will come to mind the one skilled in the art to which the invention pertains having the benefit of the teachings presented in the foregoing description and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

C l a i m s

1. Method for delivering a message to a group of devices via a mobile network (1 ).

c h a r a c t e r i z e d i n the steps of

assigning said group of devices a group identifier,

forwarding said message to a dedicated node within said mobile core network,

at said dedicated node, acquiring binding information for resolving said group identifier into individual identifiers of the member devices (2) of said group of devices, and transmitting said message to the member devices (2) of said group of devices by using said individual identifiers.

2. Method according to claim 1 , wherein said dedicated node is a serving node in the mobile core network the member devices (2) of said group of devices are associated with or an MTC-IWF (5).

3. Method according to claim 2, wherein said serving node is an MSC (7), MME (8), SGSN (9), or SMS-SC (10).

4. Method according to claim 1 , wherein said dedicated node is an MTC-IWF (5) implemented in the mobile core network.

5. Method according to any of claims 1 to 4, wherein the member devices (2) of said group of devices are MTC devices.

6. Method according to any of claims 1 to 5, wherein said message is generated by an MTC application server (3).

7. Method according to any of claims 1 to 6, wherein said message is a trigger message for the member devices (2) of said group of devices to perform a specific action.

8. Method according to any of claims 1 to7, wherein said dedicated node is a GCSE application server (1 1 ).

9. Method according to any of claims 1 to 8, wherein said dedicated node transmits said message to the member devices (2) of said group of devices by means of individual transmissions.

10. Method according to any of claims 1 to 9, wherein said dedicated node transmits said message to the member devices (2) of said group of devices by means of multicast transmissions.

1 1. Method according to any of claims 1 to 10, wherein said dedicated node keeps state of the message delivery and wherein the message is resend only to those member devices (2) of said group of devices that have not received said message correctly in the first try.

12. Method according to any of claims 1 to 1 1 , wherein said group identifier is a group MSISDN or a group IMSI.

13. Method according to any of claims 1 to 12, wherein said dedicated node acquires said binding information from the HSS (6).

14. Method according to any of claims 1 to 13, wherein group membership information per device is stored or preconfigured in the HSS (6).

15. Method according to any of claims 1 to 14, wherein said dedicated node stores a relation of the individual identifiers of the member devices (2) of said group of devices and said group identifier.

16. Method according to any of claims 1 to 15, wherein said dedicated node is informed of group memberships at the time devices attach to the mobile network (1 )-

17. Method according to any of claims 1 to 16, wherein said message, in case the member devices (2) of said group of devices are attached to different serving nodes, is forwarded to all involved serving nodes.

18. Mobile network (1 ) with a mechanism for delivering a message to a group of devices,

c h a r a c t e r i z e d i n that the mobile network (1 ) comprises a dedicated node within the mobile core network that is configured

to acquire binding information for resolving a group identifier assigned to said group of devices into individual identifiers of the member devices (2) of said group of devices, and

to transmit said message to the member devices (2) of said group of devices by using said individual identifiers.

19. Mobile network according to claim 18, wherein said dedicated node is a serving node in the mobile core network the member devices (2) of said group of devices are associated with.

20. Mobile network according to claim 19, wherein said serving node is an MSC (7), MME (8), SGSN (9), or SMS-SC (10).

21. Mobile network according to claim 18, wherein said dedicated node is a GCSE application server (1 1 ).