Negotiation applicability for inactive or idle reception of multicast services

Abstract

An apparatus in a user equipment is provided, the apparatus comprising: at least one processor and at least one memory containing computer program code, the at least one memory and the computer program code configured by the at least one processor to cause the apparatus to at least receive an indication of whether a transmission mode for inactive / idle reception of multicast is applied for a multicast session, and based on the indication, perform a procedure for enabling reception of the multicast session using the transmission mode for inactive / idle mode reception.

Description

[Technical field]

[0001] Various exemplary embodiments described herein relate to apparatus, methods, and computer program products for enabling inactive or idle reception of a multicast service. [Background technology]

[0002] For abbreviations used herein, the following meanings apply: AF Application Features AMF Access and Mobility Management Functions AS Application Server (Access and Mobility Management Function) DL Downlink MBS Multicast / Broadcast Service MBSF Multicast / Broadcast Service Function MB-SMF Multicast / Broadcast Session Management Function MB-UPF Multicast / Broadcast User Plane Function NEF Network Exposure Function NG-RAN Next Generation Radio Access Network NRF Network Repository Function PCC Policy Control and Charging PDU Protocol Data Unit QoS Quality of Service RAN Radio Access Network RRC Radio Resource Control SMF Session Management Function TMGI Temporary Mobile Group Identity UE User Equipment

[0003] 5G multicast and broadcast procedures are defined, for example, in TS 23.247. Summary of the Invention [Problem to be solved by the invention]

[0004] It is possible for a UE that joins a multicast session to have inactive / idle reception of the multicast, in which case no feedback regarding radio reception is sent from the UE to the network.

[0005] However, the quality of service may be affected by inactive / idle reception of multicast. On the one hand, this feature allows reception by a higher number of UEs in the same cell, since they do not send feedback to the network. On the other hand, radio transmissions are not adjusted based on feedback by inactive or idle UEs, and therefore transmission errors may increase.

[0006] The exemplary embodiments are particularly directed to improved handling of multicast transmissions. [Means for solving the problem]

[0007] According to a first aspect, an apparatus in a user equipment is provided, the apparatus comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured by the at least one processor to cause the apparatus to at least receive an indication of whether a transmission mode for inactive / idle reception of multicast is applied for a multicast session, and based on the indication, perform a procedure for enabling reception of the multicast session using the transmission mode for inactive / idle mode reception.

[0008] According to a second aspect, there is provided a method in a user equipment, the method comprising: receiving an indication of whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session; performing a procedure based on the indication to enable reception of the multicast session using a transmission mode for inactive / idle mode reception; Includes.

[0009] The first and second aspects may be modified as follows:

[0010] An indication as to whether inactive / idle reception of multicast applies for a multicast session may be included in the announcement for the multicast session.

[0011] A join request message for the multicast session may be sent to a network control element, and a join accept message may be received from the network control element, where the join accept message may include an indication as to whether a transmission mode for inactive / idle reception is enabled for the multicast session.

[0012] Support for idle / inactive reception of multicast may be indicated in the join request message.

[0013] A procedure for enabling reception of a multicast session using a transmission mode for inactive / idle mode reception may include monitoring broadcasted information whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session in a cell in which the UE is located.

[0014] While in the RRC inactive or RRC idle state, data for the multicast session may be received.

[0015] When multicast inactive / idle reception should be applied for a multicast session, feedback regarding reception of the multicast session to the network while the transmission mode for multicast inactive / idle reception is applied may be omitted, or less feedback regarding reception of the multicast session may be sent to the network while the transmission mode for multicast inactive / idle reception is applied than if the transmission mode for multicast inactive / idle reception is not applied for the multicast session.

[0016] According to a third aspect, there is provided an apparatus in a network element for performing an application function, the apparatus comprising: at least one processor and at least one memory containing computer program code, the at least one memory and the computer program code being configured by the at least one processor to cause the apparatus to at least request creation of a multicast session and to indicate whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session.

[0017] According to a fourth aspect, there is provided a method in a network element for performing an application function, the method comprising: requesting the creation of a multicast session; indicating whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; Includes.

[0018] The third and fourth aspects may be modified as follows:

[0019] A service announcement for the multicast session targeted to user equipment may be prepared, the service announcement including an indication of whether a transmission mode for inactive / idle reception of the multicast should be enabled for the multicast session.

[0020] According to a fifth aspect, there is provided an apparatus in a network element for performing a multicast broadcast session management function, the apparatus comprising: at least one processor and at least one memory containing computer program code, the at least one memory and the computer program code being configured by the at least one processor to cause the apparatus to at least manage the multicast session and to indicate to network elements involved in the multicast session whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session.

[0021] According to a sixth aspect, there is provided a method in a network element for performing multicast broadcast session management functions, the method comprising: Managing a multicast session; Indicating to network elements involved in a multicast session whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; Includes.

[0022] The fifth and sixth aspects may be modified as follows:

[0023] From an application function, a multicast / broadcast service function, or a network exposure function requesting the creation of a multicast session, an indication may be received as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session.

[0024] An indication may be pre-configured in the network as to whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session.

[0025] an indication to network elements involved in a multicast session of whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; An indication to the session management function, in the Nmbsmf_MBSSession_ContextStatusSubscribe response, of whether the transmit mode for inactive / idle reception of multicast should be enabled for the multicast session; An indication to the access management function in the Nsmf_PDUSession_UpdateSMContext response of whether the transmit mode for multicast inactive / idle reception should be enabled for the multicast session, or An indication to a radio access network node of whether a transmission mode for inactive / idle reception of multicast in an N2 session management container should be enabled for a multicast session. may include at least one of:

[0026] According to a seventh aspect, there is provided an apparatus in a network element performing session management functions, the apparatus comprising: at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code causing, by the at least one processor, the apparatus to at least receive a join request message for a multicast session from a user equipment; and send a join acceptance message in response to the join request message, the join acceptance message including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session. It is configured as follows.

[0027] According to an eighth aspect, there is provided a method in a network element for performing session management functions, the method comprising: receiving a join request message for a multicast session from a user equipment; sending a join acceptance message in response to the join request message, the join acceptance message including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; Includes.

[0028] The seventh and eighth aspects may be modified as follows.

[0029] The join acceptance message may include an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled in at least one of an N1 session management container to be sent to the user equipment or an N2 session management container to be sent to the radio access network node.

[0030] The join request message for the multicast session received from the user equipment may include information that the user equipment supports a transmission mode for idle / inactive reception of the multicast.

[0031] From the multicast broadcast session management function, an indication may be received as to whether a transmit mode for inactive / idle reception of multicast should be enabled for the multicast session.

[0032] The sent indication as to whether the transmission mode for inactive / idle reception of multicast should be enabled for the multicast session is: a received indication from a multicast broadcast session management function; or information received from a user equipment that the user equipment supports the transmission mode for idle / inactive reception of multicast. The determination may be based on at least one of the following:

[0033] According to a ninth aspect, there is provided an apparatus in a network element performing a radio access network node, the apparatus comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured by the at least one processor to cause the apparatus to receive information regarding a multicast session including at least an indication on whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; to determine, based at least in part on the received indication, whether to apply a transmission mode for inactive / idle reception of multicast for the multicast session in at least one radio cell served by the apparatus, and to transmit data of the multicast session in the radio cell using the determined transmission mode.

[0034] According to a tenth aspect, there is provided a method in a network element performing a radio access network node, the method comprising: receiving information regarding the multicast session, including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; determining, based at least in part on the received indication, whether to apply a transmission mode for inactive / idle reception of multicast for the multicast session in at least one wireless cell served by the device; Transmitting data of the multicast session in the wireless cell using the determined transmission mode. Includes.

[0035] The ninth and tenth aspects may be modified as follows.

[0036] In the at least one radio cell, an indication may be broadcast as to whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session; if a transmission mode for inactive / idle reception of multicast is not applied for the multicast session, user equipments that are located in the at least one radio cell and that have joined the multicast session may be kept in an RRC connected state while the multicast session is active; and if a transmission mode for inactive / idle reception of multicast is applied for the multicast session, user equipments that are located in the at least one radio cell and that have joined the multicast session may be allowed to transition to an RRC inactive state or an RRC idle state while the multicast session is active.

[0037] According to an eleventh aspect, there is provided a computer program product comprising code means for, when executed on a processing means or module, performing a method according to any one of the second, fourth, sixth, eighth and tenth aspects and / or variations thereof. The computer program product may be embodied on a computer readable medium and / or the computer program product may be directly loadable into an internal memory of a computer and / or transmittable over a network by at least one of an upload procedure, a download procedure and a push procedure.

[0038] According to a twelfth aspect, means for receiving an indication of whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session; means for performing a procedure for enabling reception of the multicast session using a transmission mode for inactive / idle mode reception based on the indication; An apparatus is provided comprising:

[0039] According to a thirteenth aspect, means for requesting the creation of a multicast session; means for indicating whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session; An apparatus is provided comprising:

[0040] According to a fourteenth aspect, means for managing a multicast session; means for indicating to network elements involved in a multicast session whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; An apparatus is provided comprising:

[0041] According to a fifteenth aspect, means for receiving a join request message for a multicast session from a user equipment; means for sending a join acceptance message in response to the join request message, the join acceptance message including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; An apparatus is provided comprising:

[0042] According to a sixteenth aspect, means for receiving information regarding the multicast session, including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; means for determining, based at least in part on the received indication, whether to apply a transmission mode for inactive / idle reception of multicast for the multicast session in at least one wireless cell served by the device; means for transmitting data of a multicast session in a radio cell using the determined transmission mode; An apparatus is provided comprising:

[0043] These and other objects, features, details and advantages will become more fully apparent from the following detailed description of illustrative embodiments taken in conjunction with the accompanying drawings. [Brief description of the drawings]

[0044] [Figure 1A] A diagram showing UE1 according to an example embodiment. [Figure 1B] A diagram showing a process performed by UE1 according to an exemplary embodiment. [Figure 2A] FIG. 2 illustrates AF2 according to an exemplary embodiment. [Figure 2B] FIG. 1 illustrates a process performed by AF2 according to an exemplary embodiment. [Figure 3A] FIG. 1 illustrates a MB-SMF3 according to an exemplary embodiment. [Figure 3B] FIG. 1 illustrates a process performed by the MB-SMF3 according to an exemplary embodiment. [Figure 4A] FIG. 2 illustrates an SMF4 according to an exemplary embodiment. [Figure 4B] FIG. 1 illustrates a process performed by SMF4 in accordance with an exemplary embodiment. [Figure 5A] FIG. 1 illustrates a RAN node according to an example embodiment. [Figure 5B] FIG. 1 illustrates a process performed by a RAN node according to an example embodiment. [Figure 6A] FIG. 2 illustrates a signal flow between several network elements when creating a multicast session according to an example embodiment. [Figure 6B]FIG. 2 illustrates a signal flow between several network elements when creating a multicast session according to an example embodiment. [Figure 7A] A diagram illustrating MBS session creation without a PCC according to an example embodiment. [Figure 7B] A diagram illustrating MBS session creation without a PCC according to an example embodiment. [Figure 8] FIG. 1 illustrates the establishment of shared distribution towards NG-RAN nodes according to an example embodiment. [Figure 9A] A diagram illustrating a PDU session change for a UE participating in a multicast session according to an example embodiment. [Figure 9B] A diagram illustrating a PDU session change for a UE participating in a multicast session according to an example embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] In the following, a description of exemplary embodiments will be provided, with the understanding that the description is given by way of example only and that the exemplary embodiments described should not be construed as limiting in any way.

[0046] Exemplary embodiments relate to, but are not limited to, 5G multicast and broadcast procedures, for example, as defined in TS 23.247.

[0047] Before describing the exemplary embodiments, some problems addressed by certain exemplary embodiments are described in a bit more detail below.

[0048] As mentioned above, in multicast transmission, the quality of service can be affected by inactive / idle reception of the multicast. On the one hand, this feature allows reception by a higher number of UEs in the same cell, since they do not send feedback to the network. On the other hand, the radio transmission is not adjusted based on the feedback by the inactive or idle UEs, and thus transmission errors may increase. Thus, according to some embodiments, an external entity creating a multicast session is enabled to control the quality of service (i.e., whether inactive / idle reception of the multicast should be applied or not).

[0049] More specifically, an external entity creating a multicast session should be able to control the quality of service (i.e. whether inactive / idle reception of multicast should be applied or not). Inactive / idle mode reception may enable service for more UEs in a cell. However, the quality of service for individual UEs may be degraded.

[0050] SUMMARY OF THE DISCLOSURE The illustrative embodiments are directed to providing improved handling of multicast transmissions that take into account the above-mentioned issues.

[0051] In the following, a general overview of some exemplary embodiments will be described with reference to Figures 1A, 1B, 2A, 2B, 3A, 3C, 4A, 4B, 5A and 5C.

[0052] FIG. 1A shows a UE1 according to the present exemplary embodiment. The UE1 is an example of an apparatus that may be a part of user equipment. A procedure executed by the UE1 is shown in FIG. 1B. The UE1 shown in FIG. 1A includes at least one processor 11 and at least one memory 12 including computer program code. The at least one processor 11, together with the at least one memory 12 and the computer program code, is configured to cause the apparatus to receive an indication of whether a transmission mode for inactive / idle reception is enabled for a multicast session (S11 in FIG. 1B), and to perform a procedure for enabling the multicast session to be received using the transmission mode for inactive / idle reception based on the indication (S12 in FIG. 1B).

[0053] Fig. 2A shows AF2 as an example of an apparatus performing an application function, which is an example of an external entity that may request to establish a multicast session. The procedure executed by AF2 is shown in Fig. 2B. AF2 shown in Fig. 2A includes at least one processor 21 and at least one memory 22 including computer program code. The at least one processor 21, together with the at least one memory 22 and the computer program code, is configured to cause the apparatus to request the creation of a multicast session (S21 in Fig. 2B) and to indicate whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session (S22 in Fig. 2B).

[0054] FIG. 3A shows MB-SMF3 as an example for an apparatus performing multicast broadcast session management function. The procedure executed by MB-SMF3 is shown in FIG. 3B. MB-SMF3 shown in FIG. 3A includes at least one processor 31 and at least one memory 32 including computer program code. The at least one processor 31, together with the at least one memory 32 and the computer program code, is configured to cause the apparatus to manage a multicast session and to cause network elements involved in the multicast session (e.g., UE1 shown in FIG. 1A, SMF4 shown in FIG. 4A, RAN shown in FIG. 5A) to indicate whether a transmission mode for inactive / idle mode inactive / idle reception of multicast should be enabled for the multicast session (S32 in FIG. 3B).

[0055] FIG. 4A shows the SMF4 as an example for an apparatus performing session management functions. The procedure executed by the SMF4 is shown in FIG. 4B. The SMF4 shown in FIG. 4A includes at least one processor 41 and at least one memory 42 including computer program code. The at least one processor 41, together with the at least one memory 42 and the computer program code, is configured to cause the apparatus to receive a join request message for a multicast session from a user equipment (e.g., UE1 shown in FIG. 1A) (S41 in FIG. 4B) and send a join acceptance message in response to the join request message, where the join acceptance message includes information regarding whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session (S42 in FIG. 4B).

[0056] FIG. 5A shows the RAN 5 as an example for an apparatus performing session management functions. The procedure executed by the RAN 5 is shown in FIG. 5B. The RAN-54 shown in FIG. 5A includes at least one processor 51 and at least one memory 52 including computer program code. The at least one processor 51 together with the at least one memory 52 and the computer program code is configured to cause the apparatus to receive information about a multicast session including an indication on whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session (S51 in FIG. 5B), to determine whether a transmission mode for inactive / idle reception of multicast should be applied for the multicast session in at least one wireless cell served by the apparatus based at least in part on the received indication (S52 in FIG. 5B), and to transmit data of the multicast session in the wireless cell using the determined transmission mode (S53 in FIG. 5B).

[0057] Thus, according to an exemplary embodiment, a new kind of information is provided in the network, namely, whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session. Based on this information, the network elements involved in the multicast session can configure their operation accordingly. For example, UE1 may not send feedback on reception of the multicast session to the network (e.g., not send feedback on radio quality) so that less traffic is generated and more UEs can join the multicast session.

[0058] Information regarding whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session may be sent, for example, in some message when the establishment of a multicast session is requested. Alternatively, the information may be pre-configured in the network.

[0059] The term "inactive / idle reception of multicast", sometimes referred to as "passive reception of multicast", means that in response to receiving the multicast, as described above, the receiver (e.g., UE1) does not need to send a response, e.g., there is no feedback.

[0060] Thus, the creator of the multicast session (AF2) and / or the network operator can decide whether there should be inactive / idle reception of the multicast in the network or for a particular multicast session, i.e., whether the creator of the multicast session or the network operator can decide whether to sacrifice radio quality to increase the number of UEs that can join the multicast session, or whether to guarantee radio quality at the expense of a reduction in the number of UEs involved in the multicast session.

[0061] The information regarding whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session may be present in the form of a parameter such as an "idle / inactive reception indicator".

[0062] The devices 1 to 4 shown in Figures 1A, 2A, 3A and 4A may include more components than those described above and may further include I / O units 13, 23, 33, 43 that are capable of transmitting to and receiving from other network elements.

[0063] In the following, the above described procedure will be explained below by referring to some further detailed embodiments, which are also referred to in Fig. 6, which will be explained in more detail later. Fig. 6, which comprises Fig. 6A and Fig. 6B, shows the signal flow between some network elements when creating a multicast session according to an exemplary embodiment, Fig. 6A shows processes A1 to A8, and Fig. 6B shows processes A9 to A14.

[0064] In particular, according to some example embodiments, when an AF requests the creation of a multicast MBS session, the AF indicates whether multicast inactive / idle reception shall be enabled for the session (see also A1 in FIG. 6). The AF may also indicate in a service announcement towards the UE whether a transmission mode for multicast inactive / idle reception should be enabled (see also A3 in FIG. 6).

[0065] Alternatively, the information whether inactive / idle reception of multicast is enabled for a multicast session is pre-configured in the network.

[0066] The MB-SMF indicates to the RAN node whether multicast inactive / idle reception is applicable when the RAN requests shared delivery for a multicast MBS session (see also A10 to A14 in FIG. 6).

[0067] The MB-SMF may also indicate to the SMF whether a transmission mode for inactive / idle reception of multicast is enabled when the SMF requests creation of an MBSSessionContext for an MBS session (see A6 in Figure 6).

[0068] When the SMF replies to the UE's join request, the SMF indicates in the join acceptance whether a transmission mode for inactive / idle reception is enabled for the multicast session based on at least one of the network capabilities, the user equipment capabilities, and the information about the multicast session provided by the AF or the preconfigured information about the multicast session.

[0069] When inactive / idle reception is applicable for a multicast session and UE: The network and the UE may negotiate the UE transition to an RRC inactive state or an RRC idle state while the UE is in an active multicast; The UE listens to multicast transmissions and related radio signaling while in an RRC inactive state or an RRC idle state; and The UE sends less or no radio level feedback regarding multicast reception while in an RRC inactive or RRC idle state.

[0070] When a multicast session is activated and a transmission mode for inactive / idle reception is applied, the network may not page the UE, thus reducing further traffic.

[0071] In the following, an example of how the AF requests the creation of a session is described by referring to the flowchart shown in Figure 6. The involved elements are the UE, NG-RAN, AMF, SMF, MB-SMF, NEF / MBSF and the AF.

[0072] It is assumed that the AF wants to establish a multicast session. At A1, the AF sends a Nnef_MBSSession_Create request (MBS Session ID, Service Type, QoS Request, Idle / Inactive Reception Indicator) to the NEF / MBSF. Note that the "Idle / Inactive Reception Indicator" is a new parameter according to this embodiment and is an example for "information on whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session".

[0073] At A2, the NEF / MBSF forwards the request (i.e., Nmbsmf_MBSSession_Create request (MBS Session ID, service type, idle / inactive receiving indicator) to the MB-SMF.

[0074] At A3, the MB-SMF establishes a session announcement that includes a new idle / inactive receiving indicator.

[0075] It is then assumed that the UE wants to join the multicast session announced by the session announcement. Thus, at A4, the UE sends a UL NAS message (N1 SM Container (PDU Session Change Request: Join)) to the AMF. At A5, the AMF sends a Nsmf_PDUSession_UpdateSMContext request to the SMF. At A6, the subscribe procedure is performed by sending a Nmbsmf_MBSSession_ContextStatusSubscribe request / response (idle / inactive receiving indicator) between the SMF and the MB-SMF. Note that now a new idle / inactive receiving indicator is included.

[0076] In A7, the SMF sends an Nsmf_PDUSession_UpdateSMContext response (N1 SM container (idle / inactive receiving indicator), N2 SM container (idle / inactive receiving indicator)) to the AMF. Note that this message also includes the new idle / inactive receiving indicator. In A8, the AMF sends an N2 message request to the NG-RAN, including the N1 SM container and the N2 SM container received in A7. Then, in A9, the RRC change is performed by sending an RRC message (PDU session change command, N1 SM container (idle / inactive receiving indicator)) between the NG-RAN and the UE.

[0077] If the NG-RAN decides to establish shared distribution for the multicast MBS session, the NG-RAN executes A10 to A13. At A10, the NG-RAN sends an N2 MBS message () to the AMF. At A11, the AMF sends a Nmbsmf_MBSSession_ContextUpdate request to the MB-SMF. At A12, the MB-SMF responds with a Nmbsmf_MBSSession_ContextUpdate response, including a new idle / inactive reception indicator. At A13, the AMF sends an N2 MBS message (idle / inactive reception indicator) to the NG-RAN.

[0078] A further embodiment is described by referring to Fig. 7, which is based on Fig. 7.1.1.2-1 of TS 23.247 and shows MBS session creation without PCC. In the following, the additions introduced according to the exemplary embodiment are highlighted. Fig. 7 includes Fig. 7A showing processes B1 to B12 and Fig. 7B showing processes B13 to B22.

[0079] In B1, the AF sends a Nnef_TMGI_AllocateRequest(TMGI number) message to the NEF / MBSF to request allocation of TMGI(s) to identify new MBS session(s). In B2, the NEF checks the authorization of the AF. In B3, the NEF / MBSF discovers and selects an MB-SMF using the NRF or based on local configuration. In B4, the NEF / MBSF sends a Nmbsmf_TMGI_AllocateRequest(TMGI number) message to the MB-SMF. In B5, the MB-SMF allocates the TMGI(s) and returns the TMGI(s) to the NEF / MBSF via a Nmbsmf_TMGI_AllocateResponse(TMGI(s), expiration time). In B6, the NEF or MBSF responds to the AF by sending a Nnef_TMGI_AllocateResponse(TMGI(s), expiration time). At B7, the AF may perform a service announcement to the UE.

[0080] In B8, it is assumed that the AF of the content provider requests the creation of a multicast session. In particular, the AF sends an Nnef_MBSSession_Create request to the NEF / MBSF, including the MBS session ID, the service type, the QoS request, and the new idle / inactive reception indicator. In B9, the NEF / MBSF checks the permission of the content provider. In B10, the NEF / MBSF discovers MB-SMF candidates, possibly based on the MBS service area, and selects the MB-SMF as an ingress control node. If a TMGI is included in B8, the NEF / MBSF finds the MB-SMF based on the TMGI. In B11, the NEF / MBSF sends an Nmbsmf_MBSSession_Create request to the MB-SMF, including the MBS session ID, the service type, the TMGI allocation indication, the MBS service area information, the ingress transport address request indication, and the new idle / inactive reception indicator.

[0081] In B12, if source-specific multicast is provided as MBS Session ID in B11, the MB-SMF updates its NF profile in the NRF with the serving MBS Session ID. If MBS service area information is received in B11, the MB-SMF updates its NF profile in the NRF with the information. In B13, the MB-SMF locally derives the required QoS parameters.

[0082] In B14, the MB-SMF selects an MB-UPF and sends a session request to the selected MB-UPF. In B15, if requested, the MB-UPF selects an ingress address (IP address and port) and a tunnel endpoint for outgoing data and provides it to the MB-SMF. In B16, in case of broadcast communication, the MB-SMF continues the procedure towards the AMF and NG-RAN as specified in clause 7.3.1. In B17, the MB-SMF indicates to the NEF / MBSF the possibly allocated ingress address. In B18, which is optional, if the MBSF decides to use the MBSTF, the NEF / MBSF provides the ingress address received in B17 towards the MBSTF as DL destination. In B19, subject to B18, if requested, the MBSTF selects an ingress address (IP address and port) and provides it to the NEF / MBSF. In B20, the NEF / MBSF-C indicates the possibly allocated ingress address and other parameters (e.g. TMGI) to the AF via a Nnef_MBSSession_Create response ([TMGI], [Allocated ingress address]). In B21, which is the same as B7, the AF may also perform a service announcement in this phase. In particular, the service announcement includes a new idle / inactive reception indicator. In B22, in case of multicast communication, depending on the configuration, the UE may join the MBS session as specified in clause 7.2.1.

[0083] A further exemplary embodiment is described by reference to Fig. 8, which is based on Fig. 7.2.1.4-1 of TS 23.247, showing the establishment of shared distribution towards NG-RAN nodes. In the following, in particular the additions according to the embodiment are described, in particular in which messages the new idle / inactive reception indicator is included.

[0084] In C1, when an NG-RAN node serves at least one UE in a multicast MBS session, the NG-RAN node decides to establish shared distribution for the multicast MBS session. In C2, the NG-RAN sends an N2 MBS Session Request message (MBS Session ID, [Area Session ID], N2 SM Info ([Unicast DL Tunnel Info])) towards the AMF. In C3, the AMF selects an MB-SMF to serve the multicast MBS session, for example, using an NRF discovery service or locally stored information. The AMF invokes an Nmbsmf_MBSSession_ContextUpdate request (MBS Session ID, [Area Session ID], N2 SM Info) to the MB-SMF in C3a. The AMF stores the information of the NG-RAN node (e.g., NG-RAN node ID) for subsequent signaling related to the multicast MBS session in C3b. Conditionally, at C4, if the MB-SMF receives unicast DL tunnel information at C3, the MB-SMF configures the MB-UPF to send multicast data for the multicast MBS session (or location-dependent content of the multicast MBS session if an area session ID is received) towards that GTP tunnel endpoint via unicast transport. At C5, the MB-SMF stores the AMF's information (e.g., AMF ID) in the MBS multicast session context (or location-dependent part of the multicast MBS session context if an area session ID is received) to enable subsequent signaling towards that AMF.

[0085] At C6, the MB-SMF sends a Nmbsmf_MBSSession_ContextUpdate response to the AMF, which in particular includes the new idle / inactive reception indicator. At C7, the AMF sends an N2 MBS Session Response message to the NG-RAN node, which also includes the response and includes the new idle / inactive reception indicator.

[0086] Another exemplary embodiment is described below by referring to Fig. 9, which is based on Fig. 7.2.1.3-1 of TS 23.247, showing PDU session modification for UEs joining a multicast session. Fig. 9 includes Fig. 9A, which shows processes D1 to D10, and Fig. 9B, which shows processes D11 to D19. This embodiment describes a variant in which the UE can indicate its support for idle / inactive reception in the join request, and the network can use this as a criterion to indicate in the join reply whether idle / inactive reception applies for the MBS session and the UE.

[0087] In order to join a multicast group, at D1, the UE sends a PDU Session Change Request for the associated PDU session, further including one or several MBS Session IDs and a Join Request. In detail, the message sent to the AMF in D1a includes a new idle / inactive reception indicator. In D2, based on the received MBS Session ID and Join Request, the SMF determines that this is an MBS Session Join Request. In D3, for each MBS session in D1, if the SMF did not subscribe to the MBS session context, the SMF subscribes to event notifications related to the multicast MBS session and invokes a Nmbsmf_MBSSession_ContextStatusSubscribe request (MBS Session ID) towards the MB-SMF to request information about the MBS session context. The MB-SMF responds with information about the indicated multicast MBS session in a Nmbsmf_MBSSession_ContextStatusSubscribe response. The request and response also include a new idle / inactive reception indicator.

[0088] At D4, the SMF performs an authorization check as described in clause 6.41 of TS 23.247. At D5, if the join request is accepted, the SMF responds to the AMF through a Nsmf_PDUSession_UpdateSMContext response (N2 SM Information (PDU Session ID, MBS Session ID, [Updated PDU Session Information], [Mapping information between (one or more) unicast QoS flows and (one or more) multicast QoS flows]), N1 SM Container (PDU Session Change Command)). This response also includes a new idle / inactive receiving indicator.

[0089] At D6, an N2 message containing the multicast MBS session information and the PDU session modification information is sent to the NG-RAN. As mentioned above, this message also contains the new idle / inactive reception indicator.

[0090] The following processes D7 through D19 correspond exactly to steps 7 through 19 in Figure 7.2.1.3-1 of TS 23.247.

[0091] Therefore, according to some example embodiments, the new idle / inactive reception indicator may be included in a different message so that corresponding network elements may be informed whether to apply idle / inactive reception for the multicast session.

[0092] The exemplary embodiments described above are by way of example only and may be modified.

[0093] The names of network elements, protocols, and methods are based on the current standard. In other versions or other technologies, the names of these network elements and / or protocols and / or methods may be different as long as they provide the corresponding functions.

[0094] In general, the exemplary embodiments may be implemented by computer software stored in memories (memory resources, memory circuits) 12, 22, 32, 42, 52 and executable by processors (processing resources, processing circuits) 11, 21, 31, 41, 51, or by hardware, or by a combination of software and / or firmware and hardware.

[0095] As used in this application, the term "circuit" refers to any of the following: (a) a hardware-only circuit implementation (e.g., an implementation in analog and / or digital circuitry only); and (b) (when applicable), (i) a combination of processor(s) or (ii) a combination of circuitry and software (and / or firmware), such as processor(s) / software, software, and memory(s) portions (including digital signal processor(s)) that work together to cause a device, such as a mobile phone or a server, to perform various functions; and (c) Any circuitry, such as a microprocessor(s) or portion of a microprocessor(s), that requires software or firmware for its operation even though the software or firmware is not physically present.

[0096] This definition of "circuitry" applies to all uses of the term in this application, including any claims. As a further example, the term "circuitry" as used in this application will also cover merely an implementation of a processor (or processors) or part of a processor and its (or their) accompanying software and / or firmware. The term "circuitry" will also cover, for example, and where applicable to certain claim elements, a baseband integrated circuit or an application processor integrated circuit for a mobile phone, or a similar integrated circuit in a server, cellular network device, or other network device.

[0097] The terms "connected" and "coupled," or any variation thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements may be physical, logical, or a combination thereof. As employed herein, two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables, and printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency, microwave, and optical (both visible and invisible) regions, as non-limiting examples.

[0098] The memories (memory resources, memory circuits) 12, 22, 32, 42, 52 may be of any type suitable for the local technology environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed and removable memories, and non-transitory computer-readable media. The processors (processing resources, processing circuits) 11, 21, 31, 41, 51 may be of any type suitable for the local technology environment and may include, as non-limiting examples, one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multi-core processor architectures.

[0099] It should be understood that the exemplary embodiments described above are illustrative and should not be construed as limiting. Various modifications and applications may occur to those skilled in the art without departing from the true spirit and scope of the exemplary embodiments.

[0100] Some exemplary embodiments provide:

[0101] 1. A method in a user equipment, comprising: receiving an indication of whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session; performing a procedure based on the indication to enable reception of the multicast session using a transmission mode for inactive / idle mode reception; A method comprising:

[0102] A further method, wherein an indication as to whether inactive / idle reception of multicast applies for the multicast session is included in the announcement for the multicast session.

[0103] The method is: sending a join request message for a multicast session to a network controlling element; receiving a join accept message from a network control element, the join accept message including an indication as to whether a transmission mode for inactive / idle reception is enabled for the multicast session; It may further include.

[0104] The method is: Indicating support for multicast idle / inactive reception in the join-request message It may further include.

[0105] In the method, a procedure for enabling reception of a multicast session using a transmission mode for inactive / idle mode reception may include monitoring broadcasted information of whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session in a cell in which the UE is located.

[0106] The method is: Receiving data for a multicast session while in RRC inactive or RRC idle state It may further include.

[0107] The method when multicast inactivity / idle reception should be applied for a multicast session: Omitting feedback to the network regarding the reception of the multicast session while a transmission mode for inactive / idle reception of multicast is applied, or While the sending mode for multicast inactivity / idle reception is applied, sending less feedback regarding the reception of the multicast session to the network than if the sending mode for multicast inactivity / idle reception was not applied for the multicast session. It may further include.

[0108] Some example embodiments may provide a method in a network element for performing an application function, the method comprising: requesting the creation of a multicast session; indicating whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; Includes.

[0109] The method is: Preparing a service announcement for a multicast session, the service announcement including an indication of whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session, the service announcement being directed to a user equipment. It may further include.

[0110] Some example embodiments may further provide a method in a network element performing multicast broadcast session management functions, the method comprising: Managing a multicast session; Indicating to network elements involved in a multicast session whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; Includes.

[0111] The method is: receiving an indication from an application function, a multicast / broadcast service function, or a network exposure function requesting creation of a multicast session as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; It may further include.

[0112] In the method, an indication may be pre-configured in the network as to whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session.

[0113] The method, comprising: an indication to network elements involved in a multicast session of whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session, comprising: An indication to the session management function, in the Nmbsmf_MBSSession_ContextStatusSubscribe response, of whether send mode for inactive / idle reception of multicast should be enabled for the multicast session; An indication to the access management function, in the Nsmf_PDUSession_UpdateSMContext response, of whether transmission mode for multicast inactive / idle reception should be enabled for the multicast session; or An indication to a radio access network node of whether a transmission mode for inactive / idle reception of multicast in an N2 session management container should be enabled for a multicast session. may include at least one of:

[0114] Some example embodiments may provide a method in a network element performing session management functions, the method comprising: receiving a join request message for a multicast session from a user equipment; sending a join acceptance message in response to the join request message, the join acceptance message including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; Includes.

[0115] In the method, the participation acceptance message: An indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled, an N1 session management container to be sent to the user equipment; or N2 session management container to be transmitted to a radio access network node It may be included in at least one of the following.

[0116] In the method, the join request message for the multicast session received from the user equipment may include information that the user equipment supports a transmission mode for idle / inactive reception of the multicast.

[0117] The method is: receiving an indication from a multicast broadcast session management function as to whether a transmit mode for inactive / idle reception of multicast should be enabled for the multicast session; It may further include.

[0118] The method, comprising: sending an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session, comprising: a received indication from a Multicast Broadcast Session Management Function; or Received information from the user equipment that the user equipment supports a transmission mode for idle / inactive reception of multicast. The determination may be based on at least one of the following:

[0119] Some example embodiments may provide a method in a network element performing a radio access network node, the method comprising: receiving information regarding the multicast session, including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; determining, based at least in part on the received indication, whether to apply a transmission mode for inactive / idle reception of multicast for the multicast session in at least one wireless cell served by the device; Transmitting data of the multicast session in the wireless cell using the determined transmission mode. Includes.

[0120] The method is: broadcasting, in at least one radio cell, an indication as to whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session; if a transmission mode for inactive / idle reception of multicast is not applied for the multicast session, keeping user equipments that have joined the multicast session and are located in at least one radio cell in an RRC connected state while the multicast session is active; allowing user equipment that has joined the multicast session and is located in at least one radio cell to transition to an RRC inactive state or an RRC idle state while the multicast session is active, if a transmission mode for multicast inactive / idle reception is applied for the multicast session; It may further include.

Claims

1. An apparatus in a user equipment, comprising: At least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to cause the at least one processor to provide an apparatus with at least: receiving an indication of whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session; Based on the indication, a procedure is performed to enable reception of the multicast session using a transmission mode for inactive / idle mode reception. An apparatus configured as follows.

2. 2. The apparatus of claim 1, wherein an indication as to whether inactive / idle reception of multicast applies for the multicast session is included in an announcement for the multicast session.

3. At least one memory and computer program code are configured to cause the apparatus to: causing a network control element to send a join request message for the multicast session; receiving a join acceptance message from a network control element, the join acceptance message including an indication as to whether a transmission mode for inactive / idle reception is enabled for the multicast session; The apparatus of claim 1 further configured to:

4. At least one memory and computer program code are configured to cause the apparatus to: Indicate support for multicast idle / inactive listening in join-request messages The apparatus according to claim 3 , configured so as to

5. 5. The apparatus according to claim 1, wherein the procedure for enabling reception of a multicast session using a transmission mode for inactive / idle mode reception comprises monitoring broadcasted information whether a transmission mode for inactive / idle reception of multicast is applied for a multicast session in a cell in which the UE is located.

6. At least one memory and computer program code are configured to cause the apparatus to: Allowing reception of multicast session data while in RRC inactive or RRC idle state The apparatus of claim 1 , further configured to:

7. When inactivity / idle reception of multicast is to be applied for a multicast session, at least one memory and computer program code are provided to the apparatus, by at least one processor, to: Omitting feedback to the network regarding the reception of the multicast session while the transmission mode for multicast inactivity / idle reception is applied, or While a transmission mode for multicast inactivity / idle reception is applied, less feedback regarding reception of the multicast session is sent to the network than if the transmission mode for multicast inactivity / idle reception was not applied for the multicast session. The apparatus of claim 1 , further configured to:

8. An apparatus in a network element for performing an application function, comprising: At least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to cause the at least one processor to provide an apparatus with at least: Request the creation of a multicast session, Indicates whether the transmit mode for inactive / idle reception of multicast should be enabled for the multicast session. An apparatus configured as follows.

9. At least one memory and computer program code are configured to cause the apparatus to: Preparing a service announcement for a multicast session, the service announcement including an indication of whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session, the service announcement being directed to a user equipment. The apparatus of claim 8 further configured to:

10. An apparatus in a network element performing a multicast / broadcast session management function, comprising: At least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to cause the at least one processor to provide an apparatus with at least: Manage the multicast session. Allowing network elements involved in a multicast session to indicate whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session An apparatus configured as follows.

11. At least one memory and computer program code are configured to cause the apparatus to: Receive an indication from an application function, a multicast / broadcast service function, or a network exposure function requesting the creation of a multicast session as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session. The apparatus of claim 10 further configured to:

12. The apparatus of claim 10, wherein an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for a multicast session is preconfigured in the network.

13. an indication to network elements involved in a multicast session of whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; An indication to the session management function in the Nmbsmf_MBSSession_ContextStatusSubscribe response of whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; An indication to the access management function in the Nsmf_PDUSession_UpdateSMContext response of whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session, or Indication to a radio access network node of whether a transmission mode for inactive / idle reception of multicast in an N2 session management container should be enabled for a multicast session 13. The apparatus according to claim 10, further comprising at least one of:

14. An apparatus in a network element performing session management functions, comprising: At least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to cause the at least one processor to provide an apparatus with at least: receiving a join request message for a multicast session from a user equipment; sending a join acceptance message in response to the join request message, the join acceptance message including an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session; An apparatus configured as follows.

15. The join acceptance message carries an indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled, an N1 session management container to be sent to the user equipment; or N2 session management container to be transmitted to a radio access network node The apparatus of claim 14 , further comprising at least one of:

16. 16. The apparatus of claim 15, wherein a join request message for a multicast session received from a user equipment includes information that the user equipment supports a transmission mode for idle / inactive reception of multicast.

17. At least one memory and computer program code are configured to cause the apparatus to: Receive an indication from a multicast broadcast session management function as to whether a transmit mode for inactive / idle reception of multicast should be enabled for the multicast session.

17. Apparatus according to any one of claims 14 to 16, configured so as to

18. The sent indication as to whether a transmission mode for inactive / idle reception of multicast should be enabled for the multicast session is a received indication from a Multicast Broadcast Session Management Function, or Received information from a user equipment that the user equipment supports a transmission mode for idle / inactive reception of multicast. The apparatus of claim 14 , wherein the determination is based on at least one of:

19. An apparatus in a network element performing a radio access network node, comprising: At least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured to cause the at least one processor to provide an apparatus with at least: receiving information regarding the multicast session, including an indication as to whether a transmission mode for inactive / idle reception of the multicast should be enabled for the multicast session; determining, based at least in part on the received indication, whether to apply a transmission mode for inactive / idle reception of multicast for the multicast session in at least one wireless cell served by the device; Transmitting data of a multicast session in a wireless cell using the determined transmission mode An apparatus configured as follows.

20. At least one memory and computer program code are configured to cause the apparatus to: - broadcasting, in at least one radio cell, an indication as to whether a transmission mode for inactive / idle reception of multicast is applied for the multicast session; if a transmission mode for inactive / idle reception of multicast is not applied for the multicast session, keeping user equipments that have joined the multicast session and are located in at least one radio cell in an RRC connected state while the multicast session is active; allowing user equipments that have joined the multicast session and are located in at least one radio cell to transition to an RRC inactive state or an RRC idle state while the multicast session is active, if a transmission mode for inactive / idle reception of multicast is applied for the multicast session; 20. The apparatus of claim 19, further configured to cause at least one of:

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