Patent Publication Number: US-11026056-B2

Title: MBMS bearer handling

Description:
TECHNICAL FIELD 
     Embodiments presented herein relate to multimedia broadcast multicast service (MBMS) bearer handling, and particularly to methods, a control node, a client node, computer programs, and a computer program product for MBMS bearer handling in a group communications system. 
     BACKGROUND 
     In communications networks, there may be a challenge to obtain good performance and capacity for a given communications protocol, its parameters and the physical environment in which the communications network is deployed. 
     An example of applications available in some communications system is group communications services. In general terms, group communication means that the same information or media is delivered to multiple client nodes. In group communication systems (e.g., Push-To-Talk (PTT) systems) the client nodes receiving the same media constitute a group of client nodes. These client nodes may be located at different locations. If many client nodes are located within the same area, multicast or broadcast based transmission using e.g., Multicast-Broadcast Multimedia Services (MBMS) is efficient for communications to the group of client nodes, because communications resources such as time and frequency resources are shared among client nodes. If client nodes are spread out over a large geographical area it can be more efficient to use unicast transmission for communications to the group of client nodes. 
     Before using MBMS there are two different activities that currently must be performed. 
     Firstly, an MBMS bearer must be activated. This will enable media to be sent over the network and be broadcasted to wireless devices hosting the client nodes. In a 3rd Generation Partnership Project (3GPP) Long Term evolution (LTE) network this is initiated in a Broadcast Multicast Service Center (BMSC) as defined in 3GPP TS 23.246 v13.2.0. 
     Secondly, the client nodes must be informed of the service being broadcasted over the MBMS bearer. This is required so that the client nodes know how to receive the media over the MBMS bearer. This procedure is commonly known as a service announcement procedure and is defined in 3GPP TS 26.346 v13.2.0. 
     The information sent in the service announcement message includes several aspects of the service that shall be broadcasted. For example, it includes a reference to the MBMS bearer, it includes Internet protocol (IP) address, ports, protocols and codecs used to receive the media that shall broadcasted. This type of information is currently essential in order for the client node to, via its hosting wireless device, receive anything on the MBMS bearer, and is therefore currently mandatory. Furthermore, the service announcement may contain several other type of information, such as service area, scheduling information, reception reporting procedures, error correction information, etc. 
     When using MBMS for group communication both of the above mandatory activities must be performed before a group call over MBMS may start. The reason for this is that, at least currently, both bearer activation and service announcement is too time consuming to be performed at the start of the group call. 
     The service announcement procedures currently used are either interactive (meaning that the client nodes request the information or a control node of the group communications service pushes the information to the client nodes) or repetitive, for example by on regular interval broadcast the information on a known broadcast bearer, which the wireless device may monitor on a regular basis. 
     Due to the group communications dynamic need for MBMS capacity, and the time consuming provisioning process (which includes both the activation of the MBMS bearer as well as the service announcement process), it can be difficult to efficiently use the MBMS capacity for a group communication system such as a PTT system. 
     Hence, there is a need for mechanisms that enable efficient use of MBMS capacity in a group communications system. 
     SUMMARY 
     An object of embodiments herein is to provide efficient use of MBMS capacity in a group communications system. 
     According to a first aspect there is presented a method for multimedia broadcast multicast service (MBMS) bearer handling in a group communications system. The method is performed by a control node. The method comprises obtaining a need for a new MBMS bearer to be activated. The method comprises activating the new MBMS bearer. The method comprises announcing MBMS bearer identity and complementary service announcement information of the new MBMS bearer on an already announced MBMS bearer, thereby announcing the new MBMS bearer. 
     Advantageously this method provides efficient MBMS bearer handling in the group communications system. 
     According to a second aspect there is presented a control node for MBMS bearer handling in a group communications system. The control node comprises processing circuitry. The processing circuitry is configured to cause the control node to obtain a need for a new MBMS bearer to be activated. The processing circuitry is configured to cause the control node to activate the new MBMS bearer. The processing circuitry is configured to cause the control node to announce MBMS bearer identity and complementary service announcement information of the new MBMS bearer on an already announced MBMS bearer, thereby announcing the new MBMS bearer. 
     Advantageously this control node provides efficient MBMS bearer handling in the group communications system. 
     According to a third aspect there is presented a control node for MBMS bearer handling in a group communications system. The control node comprises processing circuitry and a computer program product. The computer program product stores instructions that, when executed by the processing circuitry, causes the control node to perform a set of operations, or steps. The operations, or steps, involve obtaining a need for a new MBMS bearer to be activated. The operations, or steps, involve activating the new MBMS bearer. The operations, or steps, involve announcing MBMS bearer identity and complementary service announcement information of the new MBMS bearer on an already announced MBMS bearer, thereby announcing the new MBMS bearer. 
     Advantageously this control node provides efficient MBMS bearer handling in the group communications system. 
     According to a fourth aspect there is presented a control node for MBMS bearer handling in a group communications system. The control node comprises an obtain module configured to obtain a need for a new MBMS bearer to be activated. The control node comprises an activate module configured to activate the new MBMS bearer. The control node comprises an announce module configured to announce MBMS bearer identity and complementary service announcement information of the new MBMS bearer on an already announced MBMS bearer, thereby announcing the new MBMS bearer. 
     Advantageously this control node provides efficient MBMS bearer handling in the group communications system. 
     According to a fifth aspect there is presented a computer program for MBMS bearer handling in a group communications system, the computer program comprising computer program code which, when run on processing circuitry of a control node, causes the control node to perform a method according to the first aspect. 
     Advantageously this computer program provides efficient MBMS bearer handling in the group communications system. 
     According to a sixth aspect there is presented a method for multimedia broadcast multicast service (MBMS) bearer handling in a group communications system. The method is performed by a client node. The method comprises obtaining a broadcast service announcement of a new MBMS bearer on an already announced MBMS bearer from a control node of the group communications system. The service announcement comprises the MBMS bearer identity and complementary service announcement information of the new MBMS bearer. 
     Advantageously this method provides efficient MBMS bearer handling in the group communications system. 
     According to a seventh aspect there is presented a client node for MBMS bearer handling in a group communications system. The client node comprises processing circuitry. The processing circuitry is configured to cause the client node to obtain a broadcast service announcement of a new MBMS bearer on an already announced MBMS bearer from a control node of the group communications system. The service announcement comprises the MBMS bearer identity and complementary service announcement information of the new MBMS bearer. 
     Advantageously this client node provides efficient MBMS bearer handling in the group communications system. 
     According to an eighth aspect there is presented a client node for MBMS bearer handling in a group communications system. The client node comprises processing circuitry and a computer program product. The computer program product storing instructions that, when executed by the processing circuitry, causes the client node to obtain a broadcast service announcement of a new MBMS bearer on an already announced MBMS bearer from a control node of the group communications system. The service announcement comprises the MBMS bearer identity and complementary service announcement information of the new MBMS bearer. 
     Advantageously this client node provides efficient MBMS bearer handling in the group communications system. 
     According to a ninth aspect there is presented a client node for MBMS bearer handling in a group communications system. The client node comprises an obtain module configured to obtain a broadcast service announcement of a new MBMS bearer on an already announced MBMS bearer from a control node of the group communications system. The service announcement comprises the MBMS bearer identity and complementary service announcement information of the new MBMS bearer. 
     Advantageously this client node provides efficient MBMS bearer handling in the group communications system. 
     According to a tenth aspect there is presented a computer program for MBMS bearer handling in a group communications system, the computer program comprising computer program code which, when run on processing circuitry of a client node, causes the client node to perform a method according to the sixth aspect. 
     Advantageously this computer program provides efficient MBMS bearer handling in the group communications system. 
     According to an eleventh aspect there is presented a computer program product comprising a computer program according to at least one of the fifth aspect and the tenth aspect and a computer readable storage medium on which the computer program is stored. The computer readable storage medium can be a non-transitory computer readable storage medium. 
     Advantageously this computer program product provides efficient MBMS bearer handling in the group communications system. 
     Further advantageously, these methods, these control nodes, these client nodes, and these computer programs in turn enable efficient use of MBMS capacity in the group communications system. 
     Further advantageously, these methods, these control nodes, these client nodes, and these computer programs provide a time efficient service announcement process. This time efficient service announcement process enables the group communication system to utilize the MBMS resources dynamically and to on demand adjust services and add new services over MBMS. 
     Further advantageously, these methods, these control nodes, these client nodes, and these computer programs allow the client nodes to stay in idle mode and still receive service announcement information in real time. 
     It is to be noted that any feature of the first, second, third, fourth, fifth, sixth seventh, eight, ninth, tenth and eleventh aspects may be applied to any other aspect, wherever appropriate. Likewise, any advantage of the first aspect may equally apply to the second, third, fourth, fifth, sixth, seventh, eight, ninth, tenth, and/or eleventh aspect, respectively, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings. 
     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, apparatus, component, means, step, etc.” are to be interpreted openly as referring to at least one instance of the element, apparatus, 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. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which: 
         FIG. 1  is a schematic diagram illustrating a communications system according to embodiments; 
         FIG. 2 a    is a schematic diagram showing functional units of a control node name according to an embodiment; 
         FIG. 2 b    is a schematic diagram showing functional modules of a control node name according to an embodiment; 
         FIG. 3 a    is a schematic diagram showing functional units of a client node according to an embodiment; 
         FIG. 3 b    is a schematic diagram showing functional modules of a client node according to an embodiment; 
         FIG. 4  shows one example of a computer program product comprising computer readable means according to an embodiment; 
         FIGS. 5, 6, and 7  are flowcharts of methods according to embodiments; 
         FIG. 8  is a signalling diagram according to prior art; and 
         FIG. 9  is a signalling diagram according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept 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 inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional. 
       FIG. 1  is a schematic diagram illustrating a communications system  100  where embodiments presented herein can be applied. The communications system  100  is assumed to provide services for group communication and may hence be regarded as a group communications system. The group communications system  100  is, according to some aspects, a push to talk (PTT) system. 
     The communications system  100  comprises a radio access network  120 , a core network  130 , and a service network  140 . Particularly, the core network  130  comprises a packet data network gateway (PGW)  131 , a serving gateway (SGW)  132 , a mobility management entity (MME)  133 , a multicell coordination entity (MCE)  134 , a broadcast multicast service centre (BM-SC)  135 , and an MBMS gateway (MBMS GW)  136 . The PGW  131 , SGW  132 , MME  133 , MCE  134 , BM-SC  135 , and MBMS GW 136  perform functionalities as known in the art and further description thereof is therefore omitted. 
     The communications system  100  further comprises at least one control node  200  and at least one client node  300   a ,  300   b . The at least one control node  200  may be provided in, or installed on, a radio access network node  110  or in another entity or device in the radio access network  120 , in an entity or device of the core network  130 , or in an entity or device of the service network  140 . The at least one control node  200  could implement the functionality of a group communication application server (GCS AS). Each client node  300   a ,  300   b  may be provided in, or installed on, a respective wireless device  150   a ,  150   b . The radio access network  120  is operatively connected to the core network  130  which in turn is operatively connected to the service network  140 . The radio access network node  110  thereby enables the wireless devices  150   a ,  150   b , and hence the client nodes  300   a ,  300   b , to access services and exchange data as provided by the service network  140 . 
     Examples of wireless devices  150   a ,  150   b  include, but are not limited to, mobile stations, mobile phones, handsets, wireless local loop phones, user equipment (UE), smartphones, laptop computers, and tablet computers. Examples of radio access network nodes  110  include, but are not limited to, radio base stations, base transceiver stations, node Bs, evolved node Bs, and access points. As the skilled person understands, the communications system  100  may comprise a plurality of radio access network nodes  110 , each providing network access to a plurality of wireless devices  150   a ,  150   b . The herein disclosed embodiments are not limited to any particular number of radio access network nodes  110 , client nodes  300   a ,  300   b , or wireless devices  150   a ,  150   b.    
     As disclosed above, due to the group communications dynamic need for MBMS capacity, and the time consuming provisioning process, it can be difficult to efficiently use the MBMS capacity for a group communication system such as a PIT system. Furthermore, to perform an interactive service announcement would require that the wireless devices  150   a ,  150   b  hosting the client nodes  150   a ,  150   b  becomes operatively connected to the radio access network  110  (by being in radio resource control connected (RRC_CONNECTED) mode). 
     Reference is now made to the signalling diagram of  FIG. 8  illustrating a method according to prior art for activating and announcing two (or more) MBMS bearers. 
     S 301 : One MBMS bearer is activated and announced to the client nodes  300   a ,  300   b  by the control node  200 . This MBMS bearer can be used for group communication control messages such as floor control. The client nodes  300   a ,  300   b  in the wireless devices  150   a ,  150   b  are actively monitoring this group communication control messages channel. 
     Steps S 302  and S 303  are then repeated for each new MBMS bearer that needs to be activated and announced. Steps S 302  and S 303  may occur in any order. 
     S 302 : A new MBMS bearer is activated by the control node  200  based on a need for group communication. This new MBMS bearer can be used to broadcast the group communication data. 
     S 303 : An MBMS service for the new MBMS bearer is (optionally) announced to the client nodes  300   a ,  300   b  by the control node  200  according to any of the defined procedures for service announcement in 3GPP TS 26.346 v13.2.0. However the service may be inactive (if step S 303  is performed before S 302 ) as indicated by scheduling information in the service announcement information. 
     This is an issue in scenarios where there are a large number of wireless devices  150   a ,  150   b  in a small area, since it will lead to that a large number of wireless devices  150   a ,  150   b  are simultaneously switching to radio resource control connected mode when a new service announcement distributed to a large number of wireless devices  150   a  and  150   b . This may drain the capacity of one or more radio access network nodes  120  in the radio access network  110 . If service announcement is performed on a broadcast channel the wireless devices  150   a ,  150   b  are configured to receive updates repetitive based on a configured time interval. This service announcement also includes all services typically in large areas. This is not optimal for dynamic and real time service announcement requirements. 
     According to the embodiments disclosed herein there is proposed mechanisms that enable an optimized service announcement process that can be broadcasted over an MBMS bearer carrying a group communication service. The service announcement information can be sent in real time application protocol, such as the Real-Time Protocol (RTP), or its controlling protocol, the Real-time Transport Control Protocol (RTCP). The optimized service announcement information could be limited to the mandatory parts, and may optionally refer to an already announced service, which may include more complete information that applies also to the new service being announced. 
     The embodiments disclosed herein thus relate to mechanisms for MBMS bearer handling in a group communications system  100 . In order to obtain such mechanisms there is provided a control node  200 , a method performed by the control node  200 , a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the control node  200 , causes the control node  200  to perform the method. In order to obtain such mechanisms there is further provided a client node  300   a ,  300   b , a method performed by the client node  300   a ,  300   b , and a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the client node  300   a ,  300   b , causes the client node  300   a ,  300   b  to perform the method. 
       FIG. 5  is a flow chart illustrating an embodiment of a method for MBMS bearer handling in a group communications system  100  as performed by the control node  200 .  FIGS. 6 and 7  are flow charts illustrating embodiments of methods for MBMS bearer handling in a group communications system  100  as performed by the client node  300   a ,  300   b . The methods are advantageously provided as computer programs  420   a ,  420   b.    
     Reference is now made to  FIG. 5  illustrating a method for MBMS bearer handling in a group communications system  100  as performed by the control node  200  according to an embodiment. 
     It is assumed that there is a need for a new MBMS bearer to be activated in the group communications system  100 . The control node  200  is therefore configured to perform step S 102 : 
     S 102 : The control node  200  obtains a need for a new MBMS bearer to be activated. 
     The control node  200  then activates the new MBMS bearer. The control node  200  is thus configured to perform step S 104 : 
     S 104 : The control node  200  activates the new MBMS bearer. 
     The MBMS bearer handling in the group communications system  100  is based on making a service announcement of a new MBMS bearer on an already announced MBMS bearer, where the service announcement comprises complementary service announcement information. Hence, the control node  200  announces the new MBMS bearer according to step S 106 : 
     S 106 : The control node  200  announces MBMS bearer identity and complementary service announcement information of the new MBMS bearer on an already announced MBMS bearer. The new MBMS bearer is thereby announced. 
     This enables the control node  200  to quickly announce new services over a known MBMS bearer. It allows the client nodes  300   a ,  300   b  to stay in idle mode and still receive information of the new MBMS service. This allows rapid modification of MBMS capacity allocation to dynamically meet the current needs of the group communications system  100 . It also avoids massive unicast transmissions of service announcements. 
     Embodiments relating to further details of MBMS bearer handling in the group communications system  100  relating to the control node  200  will now be disclosed. 
     There may be different purposes for activating the new MBMS bearer. According to some aspects the new MBMS bearer is activated for supporting media transmission in a group call of the group communications system  100 . 
     There may be different ways to announce the new MBMS bearer. According to some aspects the MBMS bearer identity and complementary service announcement information is announced on demand and in direct response to the new MBMS bearer being activated. Hence, according to some aspects step S 106  is performed in direct response to step S 104 . 
     Reference is now made to  FIG. 6  illustrating a method for MBMS bearer handling in a group communications system  100  as performed by the client node  300   a ,  300   b  according to an embodiment. 
     As disclosed above the control node  200  in step S 106  announces MBMS bearer identity and complementary service announcement information of the new MBMS bearer on an already announced MBMS bearer. It is here assumed that the client node  300   a ,  300   b  receives this announcement. Hence, the client node  300   a ,  300   b  is configured to perform step S 204 : 
     S 204 : The client node  300   a ,  300   b  obtains a broadcast service announcement of the new MBMS bearer on the already announced MBMS bearer from the control node  200  of the group communications system  100 . The service announcement comprises the MBMS bearer identity and (mandatory and optional) complementary service announcement information of the new MBMS bearer. 
     Embodiments relating to further details of MBMS bearer handling in the group communications system  100  relating to the client node  300   a ,  300   b  will now be disclosed. 
     Reference is now made to  FIG. 7  illustrating methods for MBMS bearer handling in the group communications system  100  as performed by the client node  300   a ,  300   b  according to further embodiments. It is assumed that step S 204  is performed as disclosed above. 
     There may be different ways for the client node  300   a ,  300   b  to obtain the broadcast service announcement. According to some aspects the client node  300   a ,  300   b  monitors the already announced MBMS bearer. Hence, according to an embodiment the client node  300   a ,  300   b  is configured to perform step S 202 : 
     S 202 : The client node  300   a ,  300   b  monitors the already announced MBMS bearer upon obtaining the broadcast service announcement. Step S 202  is performed prior to step S 204 . 
     The client node  300   a ,  300   b  is then allowed to be in idle mode when obtaining the broadcast service announcement in step S 204 . 
     There may be different ways for the client node  300   a ,  300   b  to handle the complementary information. For example, according to some aspects, the client node  300   a ,  300   b  combines the complementary information with any previously received service announcement information (if existing). Hence, according to an embodiment the client node  300   a ,  300   b  is configured to perform step S 206 : 
     S 206 : The client node  300   a ,  300   b  combines the complementary service announcement information with any previously received service announcement information of the new MBMS bearer. The combining generates complete service announcement information of the new MBMS bearer. Step S 206  is performed after step S 204 . Here, the complementary service announcement information and the previously received service announcement information can both be regarded as defining partial service announcement information. 
     Embodiments which are applicable to the methods for MBMS bearer handling in the group communications system  100  as performed by both the control node  200  and the client node  300   a ,  300   b  will now be described in turn. 
     There can be different examples of the already announced MBMS bearer. According to some aspects the already announced MBMS bearer is used by the control node  200  for transmitting group communication control messages in the group communications system  100 . 
     There can be different examples of how to announce the MBMS bearer identity and complementary service announcement information. According to some aspects the MBMS bearer identity and complementary service announcement information is announced using a Real-Time Protocol (RTP), or a Real-time Transport Control Protocol (RTCP). 
     There can be different examples of complementary service announcement information. According to an embodiment the complementary service announcement information comprises group communication streaming media initialization parameters of the new MBMS bearer. Here, the streaming media initialization parameters could comprise at least one of a multicast Internet Protocol, IP, address, User datagram protocol, UDP, port information, IP source address information of media source, media protocol information, codec information and reference to at least one other announced MBMS bearer. In this respect the thus listed parameters can be reused from previous announcements. According to an embodiment the complementary service announcement information comprises at least one reference to service announcement information of at least one previously announced MBMS bearer. 
     A particular embodiment for MBMS bearer handling in a group communications system  100  based on at least some of the above disclosed embodiments will now be disclosed in detail with reference to the signalling diagram of  FIG. 9 . 
     A pre-condition for this particular embodiment is a group communication system  100  comprising a group communication application server (GCS AS) as represented by the control node  200 ) and an MBMS system as represented by the BM-SC  135 . 
     S 401 : One MBMS bearer is activated and announced to the client nodes  300   a ,  300   b  by the control node  200 . This MBMS bearer can be used for group communication control messages such as floor control. The client nodes  300   a ,  300   b  in the wireless devices  150   a ,  150   b  are actively monitoring this group communication control messages channel. One way to implement step S 401  is to perform step S 202 . 
     S 402 : An MBMS service is (optionally) announced to the client nodes  300   a ,  300   b  by the control node  200  according to any of the defined procedures for service announcement in 3GPP TS 26.346 v13.2.0. However the service may be inactive as indicated by scheduling information in the service announcement information. 
     S 403 : A new MBMS bearer is activated by the control node  200  based on a need for group communication. This new MBMS bearer can be used to broadcast the group communication data. One way to implement step S 403  is to perform any of steps S 102 , S 104 . 
     S 404 : To announce the new MBMS bearer, the control node  200  sends a service announcement message to the BM-SC  135  in the MBMS system. The new MBMS bearer is thus announced on an already announced MBMS bearer. The service announcement message for the new MBMS bearer will be broadcasted over the radio access network  120  to the wireless devices  150   a ,  150   b , and thus to the client nodes  300   a ,  300   b . This message may be carried in a RTCP packet, and can thus be sent on demand, and contains at least the minimum required parameters for the client nodes  300   a ,  300   b  to be able to start monitoring the new MBMS bearer. This includes the MBMS bearer identity in the form of a Temporary Mobile Group Identity (TMGI), the Session Description Protocol (SDP) for the session and potentially additional parameters. The SDP includes a Multicast IP address, port, source address, protocol, codec. Additionally this message may include a reference to an already announced MBMS service. This would allow reuse of other type of features such as scheduling information, error correction procedures, reception reporting procedures etc. One way to implement step S 404  is to perform step S 106  and step S 204 . 
       FIG. 2 a    schematically illustrates, in terms of a number of functional units, the components of a control node  200  according to an embodiment. Processing circuitry  210  is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product  410   a  (as in  FIG. 4 ), e.g. in the form of a storage medium  230 . The processing circuitry  210  may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA). 
     Particularly, the processing circuitry  210  is configured to cause the control node  200  to perform a set of operations, or steps, S 102 -S 106 , S 403 , S 404 , as disclosed above. For example, the storage medium  230  may store the set of operations, and the processing circuitry  210  may be configured to retrieve the set of operations from the storage medium  230  to cause the control node  200  to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry  210  is thereby arranged to execute methods as herein disclosed. 
     The storage medium  230  may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. 
     The control node  200  may further comprise a communications interface  220  for communications at least with at least one client node  300   a ,  300   b . As such the communications interface  220  may comprise one or more transmitters and receivers, comprising analogue and digital components and a suitable number of antennas for wireless communications and ports for wireline communications. 
     The processing circuitry  210  controls the general operation of the control node  200  e.g. by sending data and control signals to the communications interface  220  and the storage medium  230 , by receiving data and reports from the communications interface  220 , and by retrieving data and instructions from the storage medium  230 . Other components, as well as the related functionality, of the control node  200  are omitted in order not to obscure the concepts presented herein. 
       FIG. 2 b    schematically illustrates, in terms of a number of functional modules, the components of a control node  200  according to an embodiment. The control node  200  of  FIG. 2 b    comprises a number of functional modules; an obtain module  210   a  configured to perform step S 102 , an activate module  210   b  configured to perform step S 104 , and an announce module  210   c  configured to perform step S 106 . The control node  200  of  FIG. 2 b    may further comprise at least one optional functional module. In general terms, each functional module  210   a - 210   c  may be implemented in hardware or in software. Preferably, one or more or all functional modules  210   a - 210   c  may be implemented by the processing circuitry  210 , possibly in cooperation with functional units  220  and/or  230 . The processing circuitry  210  may thus be arranged to from the storage medium  230  fetch instructions as provided by a functional module  210   a - 210   c  and to execute these instructions, thereby performing steps S 102 -S 106 , S 403 , S 404 . 
     The control node  200  may be provided as a standalone device or as a part of at least one further device. For example, the control node  200  may be provided in a node of the radio access network  120  or in a node of the core network  130  or in a node of the service network  140 . Alternatively, functionality of the control node  200  may be distributed between at least two devices, or nodes. These at least two nodes, or devices, may either be part of the same network part (such as the radio access network or the core network or the service network) or may be spread between at least two such network parts. Some examples of where in the communications system  100  the control node  200  may be provided are illustrated in  FIG. 1 . 
     Functionality of the control node  200  may be implemented at the service layer of the protocol stack. In general terms, instructions that are required to be performed in real time may be performed in a device, or node, operatively closer to the radio access network  120  than instructions that are not required to be performed in real time. In this respect, at least part of the control node  200  may reside in the radio access network  120 , such as in the radio access network node  110 , for cases when embodiments as disclosed herein are performed in real time. 
     Thus, a first portion of the instructions performed by the control node  200  may be executed in a first device, and a second portion of the of the instructions performed by the control node  200  may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the control node  200  may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a control node  200  residing in a cloud computational environment. Therefore, although a single processing circuitry  210  is illustrated in  FIG. 2 a    the processing circuitry  210  may be distributed among a plurality of devices, or nodes. The same applies to the functional modules  210   a - 210   c  of  FIG. 2 b    and the computer program  420   a  of  FIG. 4  (see below). 
       FIG. 3 a    schematically illustrates, in terms of a number of functional units, the components of a client node  300   a ,  300   b  according to an embodiment. Processing circuitry  310  is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product  410   b  (as in  FIG. 4 ), e.g. in the form of a storage medium  330 . The processing circuitry  310  may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA). 
     Particularly, the processing circuitry  310  is configured to cause the client node  300   a ,  300   b  to perform a set of operations, or steps, S 202 -S 206 , S 401 , S 404 , as disclosed above. For example, the storage medium  330  may store the set of operations, and the processing circuitry  310  may be configured to retrieve the set of operations from the storage medium  330  to cause the client node  300   a ,  300   b  to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry  310  is thereby arranged to execute methods as herein disclosed. 
     The storage medium  330  may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. 
     The client node  300   a ,  300   b  may further comprise a communications interface  320  for communications at least with a control node  200 . As such the communications interface  320  may comprise one or more transmitters and receivers, comprising analogue and digital components and a suitable number of antennas for wireless communications and ports for wireline communications. 
     The processing circuitry  310  controls the general operation of the client node  300   a ,  300   b  e.g. by sending data and control signals to the communications interface  320  and the storage medium  330 , by receiving data and reports from the communications interface  320 , and by retrieving data and instructions from the storage medium  330 . Other components, as well as the related functionality, of the client node  300   a ,  300   b  are omitted in order not to obscure the concepts presented herein. 
       FIG. 3 b    schematically illustrates, in terms of a number of functional modules, the components of a client node  300   a ,  300   b  according to an embodiment. The client node  300   a ,  300   b  of  FIG. 3 b    comprises an obtain module  310   a  configured to perform step S 204 . The client node  300   a ,  300   b  of  FIG. 3 b    may further comprise a number of optional functional modules, such as any of a combine module  310   b  configured to perform step S 206 , and a monitor module  310   c  configured to perform step S 202 . In general terms, each functional module  310   a - 310   c  may be implemented in hardware or in software. Preferably, one or more or all functional modules  310   a - 310   c  may be implemented by the processing circuitry  310 , possibly in cooperation with functional units  320  and/or  330 . The processing circuitry  310  may thus be arranged to from the storage medium  330  fetch instructions as provided by a functional module  310   a - 310   c  and to execute these instructions, thereby performing steps S 202 -S 206 , S 401 , S 404 . 
     The client node  300   a ,  300   b  may be provided as a standalone device or as a part of at least one further device. For example, the client node  300   a ,  300   b  may be provided in a wireless device  150   a ,  150   b . Hence, any processing circuitry, communications interface and storage medium of the wireless device  150   a ,  150   b  may be shared with the processing circuitry  310 , communications interface  320  and storage medium  330  of the client node  300   a ,  300   b . It is thus not necessary for the client node  300   a ,  300   b  to have its own processing circuitry  310 , communications interface  320  and storage medium  330  as long as the processing circuitry, communications interface and storage medium of the wireless device  150   a ,  150   b  is configured to implement the functionality of the herein disclosed client node  300   a ,  300   b.    
       FIG. 4  shows one example of a computer program product  410   a ,  410   b  comprising computer readable means  430 . On this computer readable means  430 , a computer program  420   a  can be stored, which computer program  420   a  can cause the processing circuitry  210  and thereto operatively coupled entities and devices, such as the communications interface  220  and the storage medium  230 , to execute methods according to embodiments described herein. The computer program  420   a  and/or computer program product  410   a  may thus provide means for performing any steps of the control node  200  as herein disclosed. On this computer readable means  430 , a computer program  420   b  can be stored, which computer program  420   b  can cause the processing circuitry  310  and thereto operatively coupled entities and devices, such as the communications interface  320  and the storage medium  330 , to execute methods according to embodiments described herein. The computer program  420   b  and/or computer program product  410   b  may thus provide means for performing any steps of the client node  300   a ,  300   b  as herein disclosed. 
     In the example of  FIG. 4 , the computer program product  410   a ,  410   b  is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product  410   a ,  410   b  could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program  420   a ,  420   b  is here schematically shown as a track on the depicted optical disk, the computer program  420   a ,  420   b  can be stored in any way which is suitable for the computer program product  410   a ,  410   b.    
     The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.