WO2016142810A1 - Method and network node for delivering multimedia broadcast services - Google Patents

Abstract

A method for delivering a broadcast service to User Equipments (UEs) located in a geographical area is disclosed. The method comprises: receiving a message from an application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service; in response to receiving the message, determining that a number of UEs receiving the broadcast service using a unicast bearer is superior or equal to a threshold value associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service; and in response to the determination, setting up the broadcast bearer for delivering the broadcast service to the UEs located in the geographical area. A network node for carrying out this method is also disclosed.

Description

METHOD AND NETWORK NODE FOR DELIVERING MULTIMEDIA

BROADCAST SERVICES

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of provisional application No. 62/129488, filed on March 6, 2015, in the names of Eric TURCOTTE, Shabnam SULTANA, and Mai-Anh PHAN and the disclosure of which is fully incorporated herein by reference.

TECHNICAL FIELD

[0002] This disclosure relates generally to a communication network offering or delivering broadcasting and multicasting services.

BACKGROUND

[0003] Multimedia Broadcast Multicast Service (MBMS) is a point-to- multipoint interface/connection specification for existing and upcoming Third Generation Partnership Project (3GPP) cellular networks. MBMS is designed to provide efficient delivery of broadcast and multicast services, both within a cell and within the core network. For broadcast transmission across multiple cells, it defines transmission via single-frequency network configurations. Target applications include mobile TV and radio broadcasting, as well as videos, file delivery and emergency alerts.

[0004] 3GPP Service and System Aspects (SA)4 has standardized in Release 12, a feature called MooD (MBMS Operation On Demand). With this feature, it is possible for the MBMS network (also called LTE Broadcast), to enable service delivery to User Equipments (UEs) using point-to-multipoint or broadcast MBMS bearer, when the number of UEs that are listening to/consuming the same service, on unicast, in the same area, is above a certain threshold.

[0005] To do so, the MooD feature monitors the number of UEs receiving, consuming, watching or listening to a given service, for a certain geographical area. It should be noted that terms such as "receive, consume, watch or listen to" can be used interchangeably in this disclosure as they describe how the UEs 'use' the broadcast service.

[0006] If the number of UEs is above the threshold, the service is delivered to the

UEs on the MBMS bearer. If the number of UEs falls down below the threshold, the Broadcast Multicast Service Center (BM-SC) stops the MBMS bearer, and the UEs are switched back to unicast to continue receiving the service. As part of MooD, the UEs report their service consumption to the BM-SC, when they receive their service on the MBMS bearer. The service consumption report messages include the location of the UEs, such as the Cell Identifier (Cell-ID) or a list of MBMS Service Area Identifiers (SAI), and the identification of the service (using a service identifier (ID)), for example. The consumption report messages are sent to the BM-SC via a Hypertext Transfer Protocol (HTTP) POST request, for example. When the UEs listen to their service on unicast, the UEs still report to the BM-SC their service consumption in a consumption report message, carried in the Extensible Markup Language (XML) part of HTTP POST or as part of the HTTP Request for the service, for example, in the HTTP header called MooD-header.

[0007] This operational mode of MooD is described in the 3GPP Technical Report

TR 26.849 vl2.0.0.

[0008] In short, the MooD feature allows to set up a broadcast MBMS bearer in a specific MBMS Service Area when sufficient uptake of a broadcast service is detected in unicast, to deliver the same content over broadcast, rather than unicast. The MooD feature allows the MBMS network to be used in a more efficient way when a sufficient number of UEs from a same geographical area are interested in the same content at the same time.

[0009] The MooD feature also allows, upon detection that the number of UEs listening to a given service, on broadcast, in a certain area, becomes less than a certain threshold, to turn off the MBMS bearer, forcing the UEs to continue with the service on unicast.

[0010] In parallel to the development of MooD, another group in 3GPP has developed a Group Communication architecture that makes use of MBMS, referred to as Group Communication Service Enabler (GCSE). That service was developed in 3GPP SA2 Release 12, and is documented in Technical Report TR 23.768 and in Technical Specification TS 23.468. In the current Release 12 of GCSE, there is a similar function as MooD, which allows the Group Communication Service Application Server (GCS AS) to make decisions similar to what the MooD feature would allow the BM-SC to make. As such, there is a duplication of functionalities in the BM-SC and the GCS AS.

[0011] Therefore, there is a need to provide a system and a method that would obviate or mitigate the above described problems.

SUMMARY

[0012] In a first aspect of the present invention, there is provided a method for delivering a broadcast service to User Equipments (UEs) located in a geographical area. The method comprises: receiving a message from an application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service; in response to receiving the message, determining that a number of UEs located in the geographical area, and receiving the broadcast service using a unicast bearer, is superior or equal to a threshold value associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service over the geographical area; and in response to the determination, setting up the broadcast bearer for delivering the broadcast service to the UEs located in the geographical area.

[0013] The method further comprises, determining that the number of UEs receiving the broadcast service over the broadcast bearer is inferior to the threshold value associated with the geographical area, and in response to that determination, switching back to using the unicast bearer for delivering the broadcast service.

[0014] Furthermore, the method is carried out by a media delivery function such as the BM-SC and the threshold value associated with the geographical area is pre- configured in the BMSC. Alternatively, the threshold value associated with the geographical area can be provided by the application server, i.e. when the BM-SC receives the message from the application server, the message further comprising the threshold value associated with the geographical area. [0015] In a second aspect, there is provided a network node for delivering a broadcast service to User Equipments (UEs) located in a geographical area. The network node comprises a circuitry adapted to cause the network node to: receive a message from an application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service; in response to receiving the message, determine that a number of UEs located in the geographical area, and receiving the broadcast service using a unicast bearer, is superior or equal to a threshold value, associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service; and in response to the determination, set up the broadcast bearer for delivering the broadcast service to the UEs located in the geographical area.

[0016] The circuitry further comprises a processing unit connected to a memory and a communication interface.

[0017] Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Embodiments will now be described, by way of example only, with reference to the attached Figures, wherein:

[0019] Figure 1 illustrates a schematic diagram of an architecture for GSCE;

[0020] Figure 2 illustrates a method for delivering a MBMS service for UEs located in a geographical area identified by a location identifier, according to some embodiments;

[0021] Figure 3 illustrates a schematic block diagram of a network node for carrying out the method of Figure 2;

[0022] Figure 4 illustrates a flow diagram of a detailed example for delivering a

MBMS service for UEs located in a geographical area, according to some embodiments; [0023] Figure 5 illustrates another flow diagram of a detailed example for delivering a MBMS service for UEs located in a geographical area, according to some embodiments;

[0024] Figure 6 illustrates another flow diagram of a detailed example for delivering a MBMS service for UEs located in a geographical area, according to some embodiments;

[0025] Figure 7 illustrates another flow diagram of a detailed example for delivering a MBMS service for UEs located in a geographical area, according to some embodiments; and

[0026] Figure 8 illustrates another schematic block diagram of a network node according to some embodiments.

DETAILED DESCRIPTION

[0027] Reference may be made below to specific elements, numbered in accordance with the attached figures. The discussion below should be taken to be exemplary in nature, and not as limiting of the scope of the present invention. The scope of the present invention is defined in the claims, and should not be considered as limited by the implementation details described below, which as one skilled in the art will appreciate, can be modified by replacing elements with equivalent functional elements.

[0028] As mentioned hereinabove, with the existing GCSE solution, the GCS AS has a functionality which allows the GCS AS to decide to set up an MBMS bearer, based on the UE service consumption reports sent to the GCS AS. This functionality is referred to as a demand-based activation of a MBMS bearer. If this GCSE functionality is enabled, then the similar functionality in the BM-SC, such as MooD, has to be turned off, since the decision to setup an MBMS bearer based on popularity detection can be only done in one place. It is also a duplication of functionalities in a communication network when the BM- SC and the GSC AS both have a function for demand based activation of a MBMS bearer. Furthermore, since the GCS AS generally belongs to a third party, network operators usually prefer to be able to use features in the BM-SC of their own network as much as possible.

[0029] Generally stated, embodiments of the present invention allow an application server to send a message to a media delivery function, such as the BM-SC, for broadcast bearer management. More specifically, the message comprises a request for a demand-based activation of a broadcast bearer, such as the MBMS bearer. For example, the GCS AS can send a request to the BM-SC, over the MB2 interface, to activate the MooD feature of the BM-SC for a given service, identified by a service identifier (ID). In some embodiments, the request from the application server to the media delivery function for demand-based activation of the broadcast bearer may also include one or more threshold values of the number of UEs for different geographical areas, for triggering the multicast/broadcast delivery. As an example, these values will be utilized by the BM-SC in its MooD decision, instead of using the pre -configured MooD values in the BM-SC.

[0030] As examples, it should be noted that a geographical area can be a location area, which can be defined as an area in which a UE can move freely without updating the network. The location area includes one or more cells and is identified by a location identifier. The geographical area can be also a routing area, where the routing area is identified by a routing identifier. The geographical area can be a tracking area as well, where the tracking area is identified by a tracking identifier.

[0031] In the above exemplary embodiments, after receiving the request from the

GCS AS, the BM-SC, using the MooD feature, starts monitoring the uptake of the given service on unicast bearers, in a specific geographical area. Once the number of users (or UEs) equals or exceeds the threshold value, pre-configured or provided by the GCS AS, in the specific geographical area, the BM-SC then sets up an MBMS bearer for the service identified by the service ID in the specific geographical area. Following the setup of the MBMS bearer in the specific area, the given service is delivered over the MBMS bearer to the UEs.

[0032] As the service is being delivered, the BM-SC continues to monitor the number of UEs tuned to the service on the MBMS bearer in the specific geographical area. If the number of UEs becomes lower than the given threshold value for that geographical area, the BM-SC will then terminate the MBMS bearer for the service. As such, the UEs will then switch back from the MBMS bearer to their unicast bearers at that point.

[0033] In some embodiments, the media delivery function, such as the BM-SC, sends out the messages to the UEs for requesting service consumption reports. In response to the request, the UEs report back either to the GCS AS or the BM-SC.

[0034] Now turning to Figure 1, an architecture of a communication network 10 will be described. The communication network 10 includes a Home Public Land Mobile Network (H-PLMN) 14 and an application domain 15. The H-PLMN 14 is well-known in the art. It could be a 3G, 4G or 5G network. The H-PLMN 14 includes a Home Subscriber Server (HSS) 16, a database/server containing the profile of the users. The HSS 16 is connected to the Mobility Management Entity (MME) 18, which is in charge of the mobility of the user devices or User Equipments (UEs) 20. The MME 18 is also connected to the Evolved-Universal Terrestrial Radio Access Network (E-UTRAN) 22 (including eNodeBs, not shown) providing the radio access to the UEs 20. The MME 18 is also connected to a Serving/Packet data network Gate Way (S/P GW) 24 providing unicast IP connectivity to the external network, which is assumed to include the Application Domain 15 in which the GCS 12 AS resides. The E-UTRAN 22 is further connected to the MBMS- Gateway (MBMS-GW) 26, which is connected to the BM-SC 28. The MBMS-GW 26 is used to provide the MBMS service, which is controlled by the BM-SC 28. The S/P-GW 24 is connected to the Policy and Charging Rule Function (PCRF) 30, in which policies and charging rules are configured. In the application domain 15, there is provided the GCS AS 12, which is connected to the PCRF 30 through the Rx interface. The GCS AS 12 is connected to the BM-SC 28 as well, through the MB2-U (user plane) and MB2-C (control plane) interfaces. The UE 20 can directly connect and communicate to the GCS AS 12 using the GC1 interface.

[0035] Now, with reference to Figure 2, a method 50 for delivering a broadcast service for UEs 20 located in a geographical area, will be described. The method is carried out in a network node, such as a media delivery function, for example.

[0036] Method 50 starts with step 52 in which a message is received from an application server, such as the GCS AS 12, the message comprising a request for demand- based activation of a broadcast bearer for delivering the broadcast service. The message may further comprise a service identifier (ID) identifying the broadcast service, and optionally a session identifier, such as a Temporary Mobile Group Identity (TMGI), on which the broadcast bearer can be set up. The geographical area can be identified by a location identifier, such as Cell-ID.

[0037] In step 54, in response to receiving the message, the network node determines that a number of UEs 20, located in the geographical area and receiving the broadcast service using a unicast bearer, is superior or equal to a threshold value associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service over the geographical area.

[0038] In step 56, in response to that determination, the broadcast bearer is set up for delivering the broadcast service to the UEs located in the geographical area.

[0039] Furthermore, if it is determined that, at a later point, the number of UEs receiving the broadcast service over the broadcast bearer in the geographical area is inferior to the threshold value associated with the geographical area, then the UEs are switched back to using the unicast bearer to receive the broadcast service. In this case, the broadcast bearer is turned off.

[0040] For example, the broadcast service is a MBMS service, the broadcast bearer is a MBMS bearer and the media delivery function is the BM-SC 28.

[0041] Also, it should be noted that the threshold value associated with the number of UEs receiving the broadcast service for a specific location or geographical area can be pre -configured in the BM-SC 28, through an Operation Administration and Management (OAM) server, for example. It should be noted that a plurality of threshold values associated with a plurality of geographical areas can be provided, e.g. pre-configured in the BM-SC 28. Alternatively, these parameters (threshold values associated with different geographical areas) can be provided by the GCS AS 12. In this case, the message received from the GCS AS 12 in step 52 of method 50 also includes the threshold value associated with a specific geographical area.

[0042] In order to determine that the number of UEs 20 receiving the MBMS service using the unicast bearer is superior or equal to the threshold value associated with the geographical area, the BM-SC 28 regularly sends messages to the UEs 20 for requesting service consumption reports. The service consumption reports generally indicate what broadcast services the UEs are receiving/consuming, and with what type of bearers (unicast or broadcast) and the location where the UEs are located.

[0043] In response to the request messages, the UEs 20 send their service consumption reports to the BM-SC 28. The service consumption reports include the service ID identifying the broadcast service(s) that the UEs are consuming, the geographical area the UEs are located in, the UE identity (optional) and the type of bearer(s) used to consume/receive the broadcast service(s). From the received service consumption reports, the BM-SC 28 can determine a number of UEs consuming/receiving the broadcast service using unicast bearers. Then, by comparing the determined number of UEs with the threshold value, the BM-SC 28 can determine that the number of UEs 20 consuming/receiving the MBMS service identified by the service ID is superior or equal to the threshold value associated with the geographical area. For example, to determine the number of UEs, the BM-SC 28 can count the number of UEs 20 consuming/receive the same service on unicast bearers based on the received consumption reports. Based on the comparison, the BM-SC 28 decides to start an MBMS bearer for that geographical area for delivering the service to the UEs 20.

[0044] It should be noted that the number of UEs and the threshold value can be expressed as an absolute value, or a relative value (e.g. percentage), a value over a time period, an average value, etc. Persons skilled in the art would appreciate different methods and/or mathematical representations for indicating the number of UEs and the threshold value used in the comparison.

[0045] Alternatively, after receiving the request messages for service consumption reports from the BM-SC 28, the UEs 20 can send their service consumption reports to the GCS AS 12, instead of the BM-SC 28. In that case, the request messages from the BM-SC 28 to the UEs indicate that the consumption report server address is the address of the GCS AS 12. Once the GSC AS 12 receives the service consumption reports from the UEs 20, the GSC AS 12 aggregates the reports to obtain an aggregated report which is then sent to the BM-SC 28. The aggregated report can indicate the number of UEs 20 consuming a certain broadcast service identified by its service ID, for a certain area identified by a cell identifier (cell ID), for example. Alternatively, based on the aggregated report received from the GCS AS 12, the BM-SC 28 determines the number of UEs consuming a certain broadcast service.

[0046] After receiving the aggregated report from the GCS AS 12 and by comparing the determined number of UEs with the threshold value, the BM-SC 28 determines that the number of UEs consuming the MBMS service identified by the service ID is superior or equal to the threshold value associated with the geographical area. Then, the BM-SC 28 can decide to start an MBMS bearer for that geographical area for delivering that service to the UEs 20. Alternatively, the GCS AS 12 can send one or more messages to the UEs 20 for requesting the service consumption reports. Upon receipt of this request message, the UEs 20 send their service consumption reports to the GCS AS 12. After the GCS AS 12 receives the service consumption reports from the UEs 20, the GCS AS 12 aggregates the received reports to obtain an aggregated report which is then sent to the BM-SC 28. The aggregated report can indicate the number of UEs 20 consuming a specific service for a specific location. Alternatively, based on the aggregated report received from the GCS AS 12, the BM-SC 28 determines the number of UEs consuming a certain broadcast service. Upon receipt of the aggregated report from the GCS AS 12 and by comparing the indicated number of UEs with the threshold value, the BM-SC 28 determines that the number of UEs consuming the MBMS service identified by the service ID is superior or equal to the threshold value associated with the geographical area. In such a case, the BM-SC 28 can decide to start an MBMS bearer for that geographical area for delivering the service to the UEs 20. If the BM-SC 28 has determined that the number of UEs 20 consuming the broadcast service was inferior to the threshold value, then no broadcast bearer would have been set up for delivery of the broadcast service.

[0047] It should be noted that other messages, message formats or protocols can be used to inform the BM-SC 28 or GCS AS 12 about the service consumption from the UEs 20. [0048] Now turning to Figure 3, a network node 70 for carrying out the method 50 will be described. The network node 70 can be the BM-SC 28 or other media delivery functions, for example.

[0049] The network node 70 comprises a circuitry 72, which includes a memory

74 connected to a processing unit 76, which is connected to a communication interface 78.

[0050] The circuitry 72 is adapted to cause the network node 70 to perform the steps of method 50, for example.

[0051] More specifically, the memory 74 contains instructions that, when executed, cause the processing unit 76 to receive a message from an application server, such as the GCS AS 12, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service; in response to receiving the message, to determine that a number of UEs consuming the broadcast service using a unicast bearer is superior or equal to a threshold value, associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service; and in response to the determination, to set up the broadcast bearer for delivering the broadcast service to the number of UEs 20 located in the geographical area.

[0052] A computer program for controlling the network node 70 to carry out method 50 can be stored in memory 74. The memory 74 also contains the threshold values associated with different (or a plurality of) geographical areas. The memory 74 may include one or more of volatile and non-volatile memories, such as Random Access Memory ("RAM"), Read Only Memory ("ROM"), a solid state disk ("SSD"), Flash, Phase Change Memory ("PCM"), or other types of data storage. The memory 74 may be internal or distributed memory.

[0053] It will be appreciated that variations of this processing unit 76 are possible, including circuits, one or more of various types of programmable circuit elements, e.g., microprocessors, microcontrollers, digital signal processors, field-programmable application-specific integrated circuits, and the like.

[0054] Also, it is understood that the network node 70 can include additional hardware components, such as additional processing units, memories and interfaces, for performing the tasks according to embodiments of the present invention and conventional tasks well-known in the art.

[0055] Figure 4 illustrates a flow diagram of a detailed example 90 for delivering a

MBMS service for UEs 20 located in a geographical area, according to some embodiments.

[0056] Step 100: The OAM server configures the BM-SC 28 with threshold values of numbers of UEs for different geographical areas, for triggering broadcast delivery (or MBMS bearer setup). The geographical area may be identified by a location identifier (ID), such as a Cell-ID or a MBMS SAL The threshold values associated with different geographical areas can be put in a table and sent to the BM-SC 28. It is understood that other kinds of data structures can be used to hold the threshold values associated with the geographical areas. For this example, it is assumed that the table contains the following information: for Cell-ID=30, the UE number threshold value is set to 3.

[0057] Step 101 : UE1, UE2 and UE3 are assumed to be located in Cell-ID=30, for this example. For example, the Radio Access Network (RAN) can provide the Cell -ID to the UEs 20 in a system information block or message.

[0058] Step 102: the GCS AS 12 sends over the MB2-C interface a message, which includes as parameters one or more Service IDs, identifying different MBMS services. This message also contains a request for demand-based activation of a MBMS bearer for delivering the MBMS services identified by the service IDs (or a request for activation of the MooD function in the BM-SC 28). For this example, it is assumed that a single service is targeted, identified by service ID=http://MCPTT.example.com. Other examples of MBMS services include TV services, different voice streams aimed for different groups of users, etc.

[0059] Steps 103-105: UE1, UE2 and UE3 are each in a unicast session for a

MBMS service session such as Mission Critical Push To Talk (MCPTT) services with the GCS AS 12, for example.

[0060] Steps 106-108: While the UEs are using the unicast bearers for consuming the MCPTT services, the BM-SC 28 sends them a message requesting for service consumption reports. The message can be a MBMS Service Announcement, including the Associated Delivery Procedures Description (ADPD), for example. The ADPD indicates, for this example, that a Consumption Report should be used when reporting back the service consumption, to the BM-SC 28. The indication of using Consumption Report (CR) is shown as CR set to ON, e.g. CR=ON, in the Service announcement message. In 3GPP TS 26.346, this is implicitly indicated by the presence of the "rl2:consumptionReport" element in the ADPD. Furthermore, the location type regarding the geographical area to report is given by the Cell-ID. Alternatively, the location type could be set to MBMS SAI. The service announcement can also include the service ID, identifying the MBMS service being consumed by the UEs 20. The service announcements are sent over a unicast connection to the UEs 20.

[0061] Steps 109-11 1: in response to the received service announcements, the UEs

20 send their service consumption reports to the BM-SC 28. In this case, the server address in the consumption reports corresponds to the address of the BM-SC 28. The consumption reports include the location given by cell-ID, indicating where the UEs are located (in Cell-ID=30 for this example), the service ID associated with the MBMS service (http://MCPTT.example.com for this example), and a flag indicating that the UEs are consuming the service on a unicast bearer.

[0062] Step 112: upon receipt of the consumption reports from the UEs 20, the

BM-SC 28 determines that there are 3 UEs consuming the service identified by service ID=http://MCPTT.example.com, in Cell-ID=30. By comparing the determined number of UEs with the threshold value, it is determined that the number of UEs in the specified geographical area is equal to the configured threshold value received in step 100 from the OAM server. Then, the BM-SC 28 decides to trigger the setup of an MBMS bearer for that service in step 113. If the number of UEs would have been less than 3, no MBMS bearer would have been set up and the service consumption over unicast bearers would have continued. Furthermore, the UEs 20 would have continued to report their consumption reports periodically and/or upon detection of a location change, for example if a UE 20 moved from Cell-ID=30 to Cell-ID=50.

[0063] Step 113: The BM-SC 28 triggers the procedure to set up the MBMS bearer. [0064] Step 114: The BM-SC 28 sends a request to the GCS AS 12 to get the downlink Real-time Transport Protocol (RTP) session for the service-ID =http : //MCPTT.example . com .

[0065] In step 115, the GCS AS 12 sets up the downlink RTP session for the service ID requested in step 114. Alternatively, the RTP session from the GCS AS 12 to the BM-SC 28 for the service-ID=http://MCPTT.example.com could have been started earlier at any point after step 102. However, to prevent setting up the RTP session (user plane) from the GCS AS 12 to the BM-SC 28, in case the MooD conditions to set up an MBMS bearer at the BM-SC are not met, it may be beneficial to wait until the BM-SC 28 has decided to set up the MBMS bearer (steps 112 and 113), before establishing the RTP session over MB2-U.

[0066] Step 116: the BM-SC 28 starts the MBMS Session on a Temporary Mobile

Group Identity (TMGI)=x, that was received in step 102, and in the geographical area identified by Cell-ID=30. Then, the BM-SC 28 starts sending the service- ID=http:MCPTT/example.com to the MBMS bearer. The geographical area that includes Cell-ID=30 may be an MBMS SAI, which could have been determined by the BM-SC 28 based on a pre -configured mapping table between Cell-IDs and MBMS SAIs, for example. The geographical area can alternatively be a list of one to many cells that include Cell- ID=30.

[0067] Step 117: The Radio Access network (RAN, which includes E-UTRAN)) establishes the requested MBMS bearer on the requested TMGI=x, so that the MBMS bearer can be detected by UE1, UE2 and UE3. The detection of the MBMS bearer by the UEs 20 is a trigger for the UEs 20 to switch the service downlink to the MBMS bearer.

[0068] Steps 118-119: the MBMS service content is provided to the RAN from the

BM-SC 28 over the MBMS bearer, the content could be then consumed by UE1, UE2, UE3 and any other UEs located at the same location.

[0069] Step 120: the content is delivered to all the UEs 20 that are tuned to the

MBMS bearer in the geographical area, i.e. UE1, UE2 and UE3 in this example.

[0070] Steps 121-123: UE1, UE2 and UE3 send their consumption report to the

BM-SC 28, which includes service-ID=http://MCPTT.example.com, indicating that they are listening to the MBMS bearer, their geographical area identified by the cell-ID, indicating where they are located. Optionally, the consumption report can include the client-ID, which may be used to identify the Mobile Station International Subscriber Directory Number (MSISDN) of the UE, as per 3 GPP TS 26.346.

[0071] Now turning to Figure 5, a flow diagram of a detailed example 190 for delivering a MBMS service for UEs 20 located in a geographical area, according to some embodiments, will be described.

[0072] Steps 200 and 201 are similar to steps 100 and 101 of Figure 4.

[0073] Step 202: the GCS AS 12 sends over the MB2-C interface a message for monitoring the MBMS service. The message comprises the following parameters: one or more Service-IDs (for this example, a single service-ID=http://MCPTT.example.com is assumed), and a table comprising different UE number threshold values associated with different geographical areas. For example, the table can include Cell-ID=30 associated with threshold=3. The threshold value sent by the GCS AS 12 to the BM-SC 28 overrides (or takes precedence over) the value of the threshold value that was pre-configured in the BM-SC 28 as provided in step 200. It should be noted that other data structures could be used to store the UE number threshold value per geographical area for triggering broadcast delivery.

[0074] Steps 203-211 are similar to steps 103-111 of Figure 4.

[0075] Step 212: The BM-SC 28 determines that there are 3 UEs in a unicast session for the service-ID=http://MCPTT.example.com, in Cell-ID=30. By comparing the number of UEs with the threshold value, it is determined that the number of UEs is equal to the threshold value received in step 202 from the GCS AS 12. The BM-SC 28 then decides to trigger the setup of the MBMS bearer. It should be noted that the threshold value used by the BM-SC 28 to make this decision is received in step 202, and not the pre- configured value.

[0076] Steps 213-223 are similar to steps 113-123 of Figure 4.

[0077] Now turning to Figure 6, a flow diagram of a detailed example 290 for delivering a MBMS service for UEs located in a geographical area, according to some embodiments, will be described. [0078] Steps 300-305 are similar to steps 100-105 of Figure 4.

[0079] Steps 306-308: The BM-SC 28 sends a message to the UEs 20 to request for service consumption reports, the message being a MBMS Service Announcement, including the Associated Delivery Procedures Description (ADPD), for example. The ADPD indicates, for this example, that the address of the consumption server is the address of the GCS AS 12 and that a consumption report should be used when reporting back their service consumption, to the GCS AS 12. The indication for using Consumption Report (CR) is shown as CR set to ON, e.g. CR=ON, in the Service announcement message. Furthermore, the location type (or geographical area) to report is specified to be the Cell-ID. Alternatively, the location type could be set to MBMS SAI. The Service announcement can also include the service ID, identifying the MBMS service being consumed by the UEs 20. The service announcements are sent over a unicast connection to the UEs 20.

[0080] Steps 309-311 : the UEs 20 report their service consumption reports or consumption reports to the GCS AS 12. The consumption reports include the cell-ID identifying the location where they are located (Cell-ID=30 for this example), the service- ID associated with the MCPTT service (http://MCPTT.example.com), and a flag indicating that they are consuming the service on unicast bearer.

[0081] Step 312: The GCS AS 12 summarizes/aggregates the received consumption reports for each service-ID to obtain an aggregated report, called for example Location Report. The aggregated report includes the service-ID, a list of UEs 20 (identified by the client-IDs) and their corresponding locations. The aggregated report is sent to the BM-SC 12. The Location Report can optionally include the TMGI on which to set up the MBMS Bearer.

[0082] Step 313: this step is similar to step 112 of Figure 4. Indeed, the BM-SC 12 determines that there are 3 UEs consuming the service with service- ID=http://MCPTT.example.com, in Cell-ID=30, from the aggregated report. By comparing the number of UEs with the threshold value, it is determined that the number of UEs 20 is equal to the configured threshold value received in step 300 from the OAM server, the BM-SC 28 decides to trigger the setup of an MBMS Bearer for that service. If the number of UEs would have been less than 3, no MBMS bearer would have been set up and the service consumption over unicast bearers would have continued. The UEs 20 would have continued to report their Consumption Reports periodically and upon detection of a location change, for example when a UE 20 moves from Cell-ID=30 to Cell-ID=70.

[0083] Steps 314-321 are similar to steps 113-120 of Figure 4.

[0084] Steps 322-324: UE1, UE2 and UE3 continue to send periodically the

Consumption Reports to the GCS AS 12. The consumption report includes the service- ID=http://MCPTT.example.com, which indicates the service they are consuming on the MBMS bearer, and the geographical area specified by the cell-ID, which indicates where they are located. Optionally, the consumption report can include the client-ID, which may be used to identify the MSISDN of the UE, as per 3 GPP TS 26.346.

[0085] Now turning to Figure 7, a flow diagram of a detailed example 390 for delivering a MBMS service for UEs located in a geographical area, according to some embodiments, will be described.

[0086] Steps 400 and 401 are similar to steps 100 and 101 of Figure 4.

[0087] Steps 402-404: the GCS AS 12 sends a message to the UEs 20 for requesting a service consumption report, over the GC1 interface. This message is similar to the Service announcement. This message notifies the UEs 20 how to report back to the GCS AS 12. For example, the message includes the location type to report (Cell-ID or MBMS SAIs), the percentage of the UEs 20 that should report, the service-ID in the format of Uniform Resource Name (URN), for example, for which the UEs 20 should report. Alternatively, the UEs 20 may also be configured through other means to provide this information, e.g. with Open Mobile Alliance (OMA) Device Management (DM), or with a configuration file.

[0088] Steps 405-407 are similar to steps 103-105 of Figure 4.

[0089] Steps 408-410: while the UEs 20 are in a unicast session for MCPTT services (in steps 405-407), they report their service consumption to the GCS AS 12, in response to the messages received in steps 402-404. The service consumption reports, called location reports in this case, should include, the Cell-IDs or MBMS SAIs for the location where the UEs are located, the service ID of the MBMS service that the UEs are consuming, the client-ID of the UEs and the type of bearer (unicast for example) used for consuming the MBMS service.

[0090] Step 411 : the GCS AS 12 summarizes/aggregates the received UE location reports for each service-ID to obtain an aggregated report, which is sent to the BM-SC 28. The aggregated report is called Aggregated Geographical Report, which includes the service-ID, a list of UEs 20 (identified by the client-IDs) and their corresponding locations to the BM-SC 28. The aggregated report can optionally include the TMGI on which to set up the MBMS Bearer.

[0091] Steps 412-413 are similar to steps 112-113 of Figure 4.

[0092] Steps 414-416: the BM-SC 28 sends MBMS Service Announcements to the

UEs 20 to update them regarding the MBMS service. In this case, the service announcement has the parameter CR=OFF (indicated implicitly by the absence of the "rl2:consumptionReport" element in the ADPD), meaning that the Consumption Reporting is off, because the GCS AS 12 is in control of the reporting process, and the UEs 20 report back to the GCS AS 12 (see steps 408-410).

[0093] Step 417: The BM-SC 28 sends a request to the GCS AS 12 to get the downlink RTP session for the service-ID=http://MCPTT.example.com.

[0094] In step 418, the GCS AS 12 sets up the downlink RTP session for the service-ID requested in step 417. Alternatively, the RTP session from the GCS AS 12 to BM-SC 28 for the service-ID=http://MCPTT.example.com could have been started earlier at any point after step 404. However, to prevent setting up the RTP session (user plane) from the GCS AS 12 to the BM-SC 28, in case the MooD conditions to set up an MBMS bearer at the BM-SC 28 are not met, it may be beneficial to wait until the BM-SC 28 has decided to set up the MBMS bearer (steps 412 and 413), before establishing the RTP session over MB2-U.

[0095] Steps 419-423 are similar to steps 116-120 of Figure 4.

[0096] Steps 424-426: UE1, UE2 and UE3 send their respective location report to the GCS AS 12. The location reports include the service-ID=http://MCPTT.example.com, an indication that the UEs 20 are listening to the MBMS bearer, and their geographical area identified by Cell-ID, which indicates where they are located. Optionally, the location reports can include the client-ID, which may be used to identify the MSISDN of the UEs 20.

[0097] It should be appreciated that the processing unit 76 of Figure 3, when configured with appropriate program code, may be understood to comprise several functional "modules," where each module comprises program code for carrying out the corresponding function, when executed by an appropriate processor.

[0098] Thus, for example, Figure 8 illustrates a network node adapted to carry out method 50 and which may be understood to comprise a receiving module 510, a determining module 520 and a setting up module 530. The network node 500 can be a media delivery function, such as the BM-SC 28.

[0099] The receiving module 510 is configured to receive a message from an application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service.

[00100] The determining module 520 is configured to, in response to receiving the message, determine that a number of UEs located in the geographical area consuming the broadcast service using a unicast bearer is superior or equal to a threshold value, associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service.

[00101] The setting up module 530 is configured to, in response to the determination, set up the broadcast bearer for delivering the broadcast service to the number of UEs located in the geographical area.

[00102] In general, operator controlled BM-SC has a better knowledge of the radio network and the switching threshold values in different areas, thus, the operator controlled BM-SC can make optimized decisions with respect to usage of radio resources as opposed to the GSC-AS. As such, it may be advantageous to be able to use the demand-based activation of a MBMS bearer feature of the BM-SC for all applications that may be developed on the GCS AS. Also, if this functionality from the BM-SC is not used, then the GCS AS needs to design such a functionality for all the GCS AS applications. [00103] Embodiments may be represented as a software product stored in a machine-readable medium (such as the non-transitory machine readable storage media also referred to as a computer-readable medium, a processor-readable medium, or a computer usable medium having a computer readable program code embodied therein). The non-transitory machine -readable medium may be any suitable tangible medium including a magnetic, optical, or electrical storage medium including a diskette, compact disk read only memory (CD-ROM), digital versatile disc read only memory (DVD-ROM) memory device (volatile or non-volatile) such as hard drive or solid state drive, or similar storage mechanism. The machine-readable medium may contain various sets of instructions, code sequences, configuration information, or other data, which, when executed, cause a processor to perform steps in a method according to an embodiment. Those of ordinary skill in the art will appreciate that other instructions and operations necessary to implement the described embodiments may also be stored on the machine- readable medium. Software running from the machine-readable medium may interface with circuitry to perform the described tasks.

[00104] The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.

Claims

CLAIMS What is claimed is:

1. A method for delivering a broadcast service to User Equipments (UEs) located in a geographical area, the method comprising:

receiving a message from an application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service;

in response to receiving the message, determining that a number of UEs, located in the geographical area, and receiving the broadcast service using a unicast bearer, is superior or equal to a threshold value, associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service over the geographical area; and

in response to the determination, setting up the broadcast bearer for delivering the broadcast service to the UEs located in the geographical area.

2. The method of claim 1, further comprising:

determining that the number of UEs receiving the broadcast service over the broadcast bearer is inferior to the threshold value associated with the geographical area; and

in response to the determination, switching back to using the unicast bearer for delivering the broadcast service.

3. The method of any of claims 1-2, wherein the broadcast service is a Multimedia Broadcast Multicast Service (MBMS), and the broadcast bearer is an MBMS bearer.

4. The method of any claims 1-3, wherein the threshold value associated with the geographical area is pre -configured in a Broadcast Multicast Service Center (BMSC).

5. The method of any of claims 1-3, wherein the message received from the application server further comprises the threshold value associated with the geographical area.

6. The method of claim 1, further comprising receiving a plurality of threshold values associated with a plurality of geographical areas.

7. The method of any claims 1-6, wherein the message further comprises a service identifier for identifying the broadcast service that the UEs are receiving, and a session identifier on which to set up the broadcast bearer.

8. The method of any claims 1-6, wherein determining that a number of UEs consuming the broadcast service using a unicast bearer is superior or equal to a threshold value associated with the geographical area comprises:

sending a message to the UEs located in the geographical area to request service consumption reports;

in response to the request message, receiving the service consumption reports from the UEs, the service consumption reports including a location identifier identifying the geographical area, a service identifier identifying the broadcast service and a type of bearer used to consume the broadcast service;

based on the received service consumption reports, determining a number of UEs receiving the broadcast service on a unicast bearer; and

comparing the determined number of UEs with the threshold value.

9. The method of any claims 1-6, wherein determining that a number of UEs receiving the broadcast service using a unicast bearer is superior or equal to a threshold value associated with the geographical area comprises:

sending a message to the UEs in the geographical area to request service consumption reports, the message indicating that the UEs are to send the service consumption reports to the application server; in response to the request message, receiving an aggregated report from the application server, the aggregated report including a number of UEs consuming the broadcast service on a unicast bearer; and

comparing the number of UEs with the threshold value.

10. The method of any claims 1-6, wherein determining that a number of UEs receiving the broadcast service using a unicast bearer is superior or equal to a threshold value associated with the geographical area comprises:

sending a message to the UEs in the geographical area to request service consumption reports, the message indicating that the UEs are to send the service consumption reports to the application server;

in response to the request message, receiving an aggregated report from the application server;

determining a number of UEs receiving the broadcast service on a unicast bearer based on the aggregated report including; and

comparing the determined number of UEs with the threshold value.

11. A network node for delivering a broadcast service to User Equipments (UEs) located in a geographical area, the network node comprising a circuitry adapted to cause the network node to:

receive a message from an application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service;

in response to receiving the message, determine that a number of UEs located in the geographical area and receiving the broadcast service using a unicast bearer, is superior or equal to a threshold value, associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service; and in response to the determination, set up the broadcast bearer for delivering the broadcast service to the UEs located in the geographical area.

12. The network node of claim 11, wherein the circuitry comprises a processing unit, a communication interface and a memory, the memory containing instructions that, when executed, cause the processing unit to:

receive the message, through the communication interface, from the application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service;

in response to receiving the message, determine that a number of UEs receiving the broadcast service using a unicast bearer is superior or equal to a threshold value, associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service; and

in response to the determination, set up the broadcast bearer for delivering the broadcast service to the UEs located in the geographical area.

13. The network node of claim 12, wherein the processing unit further determines that the number of UEs receiving the broadcast service over the broadcast bearer is inferior to the threshold value associated with the geographical area, and in response to that determination, the processing unit switches back to using the unicast bearer for delivering the broadcast service.

14. The network node of any claims 11-13, wherein the broadcast service is a Multimedia Broadcast Multicast Service (MBMS) and the broadcast bearer is a MBMS bearer.

15. The network node of any claims 11-14, wherein the threshold value associated with the geographical area is pre-configured in a Broadcast Multicast Service Center (BMSC).

16. The network node of any claims 11-14, wherein the message received from the application server, further comprises the threshold value associated with the geographical area.

17. The network node of claim 12, wherein the processor unit receives a plurality of threshold values associated with a plurality of geographical areas.

18. The network node of any claims 11-16, wherein the received message further comprises a service identifier for identifying the broadcast service that the UEs are receiving, and a session identifier on which to set up the broadcast bearer.

19. The network node of any claims 11-18, wherein the processing unit, in determining that a number of UEs consuming the broadcast service using a unicast bearer is superior or equal to a threshold value associated with the geographical area, sends a message to the UEs in the geographical area for requesting service consumption reports; in response to the request message, receives the service consumption reports from the UEs, the service consumption reports including a location identifier identifying the geographical area, a service identifier identifying the broadcast service and a type of bearer used to receive the broadcast service; based on the received consumption reports, determines a number of UEs receiving the broadcast service on a unicast bearer; and compares the determined number of UEs with the threshold value.

20. The network node of any of claims 11-18, wherein the processing unit, in determining that a number of UEs receiving the broadcast service using a unicast bearer is superior or equal to a threshold associated with the geographical area, sends a message to the UEs in the geographical area for requesting service consumption reports; in response to the request message, receives an aggregated report from the application server, the aggregated report including a number of UEs receiving the broadcast service on a unicast bearer, and compares the indicated number of UEs with the threshold value.

21. The network node of any of claims 11-18, wherein the processing unit, in determining that a number of UEs receiving the broadcast service using a unicast bearer is superior or equal to a threshold associated with the geographical areas, sends a message to the UEs in the geographical area to request service consumption reports, the message indicating that the UEs are to send the service consumption reports to the application server; in response to the request message, receives an aggregated report from the application server; determines a number of UEs receiving the broadcast service on a unicast bearer based on the aggregated report including; and comparing the determined number of UEs with the threshold value.

22. A network node for delivering a broadcast service to User Equipments (UEs) located in a geographical area, the network node comprising:

a receiving module configured to receive a message from an application server, the message comprising a request for demand-based activation of a broadcast bearer for delivering the broadcast service;

a determining module, configured to, in response to receiving the message, determine that a number of UEs located in the geographical area and receiving the broadcast service using a unicast bearer is superior or equal to a threshold value, associated with the geographical area, the threshold value being used for triggering a broadcast delivery of the broadcast service; and

a setting up module, configured to, in response to the determination, set up the broadcast bearer for delivering the broadcast service to the UEs located in the geographical area.