Method and device for shared distribution of IP multicast - Patents.com

Abstract

A method is provided that is performed by a first network node, the method including: sending a first request for modification of a multicast broadcast service (MBS) related PDU (packet data unit) session to a first functional node, and receiving a first acknowledgement for the modification of the MBS related PDU session and an access stratum (AS) PDU session parameters message from a second network node. This solution enables AN delivered multicast to be combined with a 5G control plane to enable personalized policies and charging.

Description

[Technical field]

[0001] The present disclosure relates generally to the field of communications, and more particularly to a method and device for shared delivery of Internet Protocol (IP) multicast. [Background technology]

[0002] This section introduces aspects that may facilitate a better understanding of the present disclosure. Accordingly, the statements in this section should be read in this light and not understood as admissions about what is in the prior art or what is not in the prior art.

[0003] Wireless Wireline Convergence (WWC) aims to converge wired access onto the 5G core network.

[0004] One aspect not fully addressed to date by the WWC standardization work is the delivery of linear IPTV. In existing wired networks, this can be delivered using multicast from the Broadband Network Gateway (BNG) or via multicast delivered from the Access Node (AN). Multicast from the AN is the most efficient solution and is deployed by multiple operators.

[0005] 5MBS (5G Multicast Broadcast Service) aims to provide multicast and broadcast services for 5G systems. In the case of fixed wireless access using 5G wireless as an alternative access to wireline, it is also the only mechanism available for multicast services.

[0006] 5MBS (TS 23.247) uses the following terms:

[0007] 5GC (5th Generation Core) Dedicated MBS Traffic Delivery: The 5G CN (Core Network) receives a single copy of MBS data packets and delivers separate copies of those MBS data packets to individual UEs (User Equipments) via per-UE PDU (Packet Data Unit) sessions; hence, for each such UE, one PDU session needs to be associated with the multicast session.

[0008] 5GC shared MBS traffic delivery: The 5G CN receives a single copy of MBS data packets and delivers a single copy of those MBS data packets to the RAN node.

[0009] In the case of WWC with AN-based multicast and PON, there is the possibility of shared and individual distribution in the access nodes, so the use of these terms in this disclosure is in the spirit of TS 23.247, but generalized and used outside the 5GS context: Shared delivery - a single copy is transmitted over a physical or virtual (tunnel) link that can ultimately be distributed to multiple subscribers; Individual delivery - A copy for each subscriber is sent over a physical or virtual link.

[0010] In existing deployments, wireline operators deploy AN or BNG-based multicast using IGMP (Internet Group Management Protocol) signaling to support linear IPTV services.

[0011] The general operation mode of AN-based multicast is as follows: - IGMP requests sent by the STB (Set Top Box) and relayed by the RG (Residential Gateway); - The AN uses industry-standard IGMP proxy operations to snoop requests, perform access control, and aggregate valid requests into a multicast VLAN (Virtual Local Area Network), after basic access control checks. - Aggregated IGMP loses identity; - AN may proxy report to BNG to support "bandwidth adjust" on a per-subscriber basis; - This requires some means of communicating the RG identity and multicast group to the BNG so that the BNG knows the subscriber and the associated bandwidth profile.

[0012] BNG-based multicast simply considers the BNG as a multicast router that terminates subscriber IGMP requests.

[0013] 5GS Release 16 provides the equivalent of BNG based multicast. The UPF (User Plane Function) terminates STB originated IGMP messages.

[0014] FIG. 1 shows the current architecture of AN or BNG-based multicast.

[0015] With regard to linear IPTV and 5G systems, operators will want to include access node delivered multicast for IPTV as part of the convergence on 5G systems.

[0016] However, this desire also includes not modifying the deployed device.

[0017] The primary motivation is efficiency, to significantly offload traffic from the BNG, which correspondingly applies to the AGF (Access Gateway Function) / UPF deployment.

[0018] 5MBS, defined by 3GPP (3rd Generation Partnership Project) for Release 17, provides an opportunity to do this and introduces additional components into the architecture, which are common to FWA (Fixed Wireless Access), eMBB (Enhanced Mobile Broadband) and WWC.

[0019] It is desirable to have a solution that maximizes commonality between wired and FWA access, is easily adaptable to future enhancements to 5G systems, and can leverage AN multicast delivered in existing access networks without degrading the policy and billing capabilities that 5G systems provide. Summary of the Invention

[0020] One consideration driven by business requirements is that converged access to 5G systems can be retrofitted to deployed and unmodified access networks. This includes DSLAMs (Digital Subscriber Line Access Multiplexers) for DSL access and OLTs (Optical Line Terminals) for PON (Passive Optical Network)-Fiber access. Many of these devices in the access network are either aging or have limited footprint implementations (e.g. pluggable modules) and are not suitable for upgrade. More linear IPTV is a declining business limiting the business case for system upgrades.

[0021] Existing systems are based on IGMP originating from set-top boxes connected to the home LAN, which are relayed to the core network by the RG.

[0022] Several proposals have been discussed that do not use 5MBS but seek to exhibit similar characteristics. All have significant operational drawbacks.

[0023] The solution uses both 5GS signaling procedures and legacy procedures in parallel so that legacy components in the system can be coupled to 5G procedures at the Access Gateway Function (AGF) without actually modifying the legacy equipment.

[0024] A solution is proposed herein for integrating legacy AN-based IPTV distribution into a 5G system using 5MBS. This solution works whether the 5MBS is deployed wired or not. This solution can be made to work with ATSSS (access traffic steering splitting and switching) or with multi-access handover, has common NAS procedures with FWA, minimizes variations in RG implementation, and limits changes to the wired network (no changes to 5GS N1, N2, or N3 interfaces).

[0025] According to a first aspect of the present disclosure, there is provided a method performed by a first network node, the method including: sending a first request for a modification of an MBS (Multicast Broadcast Service) related PDU (Packet Data Unit) session to a first functional node, and receiving a first acknowledgement for the modification of the MBS related PDU session and an AS (Access Stratum) PDU session parameters message from a second network node.

[0026] In an alternative embodiment of the first aspect, the AS PDU session parameters message may indicate the use of IGMP (Internet Group Management Protocol) and IPoE (Internet Protocol over Ethernet) encapsulation.

[0027] In another alternative embodiment of the first aspect, the AS PDU session parameters message may be a multicast parameters message including a multicast discriminator type, a multicast discriminator value, and an auxiliary procedure.

[0028] In another alternative embodiment of the first aspect, the method may further include, before sending the first request, sending a second request for establishment of the MBS-related PDU session to the first functional node, and receiving a second acknowledgment for establishment of the MBS-related PDU session from the second network node.

[0029] In another alternative embodiment of the first aspect, the method may further include, after receiving the first acknowledgment, sending a third request for IGMP join to a third network node.

[0030] According to a second aspect of the present disclosure, there is provided a method performed by a second network node, the method including adding a subscriber to a Multicast Broadcast Service (MBS) shared distribution session, and sending a first acknowledgement for a modification of an MBS-related Packet Data Unit (PDU) session and an Access Stratum (AS) PDU session parameters message to the first network node.

[0031] According to a third aspect of the present disclosure, there is provided a method performed by a third network node, the method including receiving an Internet Group Management Protocol (IGMP) join request for multiple groups from the first network node and adding a subscriber drop as a new leaf.

[0032] According to a fourth aspect of the present disclosure, there is provided a first network node comprising a processor and a memory communicatively coupled to the processor and configured to store instructions that, when executed by the processor, cause the first network node to perform operations of a method according to the first aspect above.

[0033] According to a fifth aspect of the present disclosure there is provided a first network node, the first network node being configured to perform a method according to the first aspect above.

[0034] According to a sixth aspect of the present disclosure, there is provided a second network node comprising a processor and a memory communicatively coupled to the processor and configured to store instructions that, when executed by the processor, cause the second network node to perform operations of the method according to the second aspect above.

[0035] According to a seventh aspect of the present disclosure there is provided a second network node, the second network node being configured to perform the method according to the second aspect above.

[0036] According to an eighth aspect of the present disclosure there is provided a third network node comprising a processor and a memory communicatively coupled to the processor and configured to store instructions that, when executed by the processor, cause the third network node to perform operations of the method according to the third aspect above.

[0037] According to a ninth aspect of the present disclosure there is provided a third network node, the third network node being configured to perform the method according to the third aspect above.

[0038] According to a tenth aspect of the present disclosure, there is provided a communication system, the communication system including a first network node according to the fourth or fifth aspect, a second network node according to the sixth or seventh aspect in communication with at least the first network node, and a third network node according to the eighth or ninth aspect in communication with at least the first network node and the second network node.

[0039] According to an eleventh aspect of the present disclosure there is provided a non-transitory computer readable medium having stored thereon a computer program which, when executed by a set of one or more processors of a first network node, causes the first network node to perform operations of a method according to the first aspect above.

[0040] According to a twelfth aspect of the present disclosure there is provided a non-transitory computer readable medium having stored thereon a computer program which, when executed by a set of one or more processors of a second network node, causes the second network node to perform operations of a method according to the second aspect above.

[0041] According to a thirteenth aspect of the present disclosure there is provided a non-transitory computer readable medium having stored thereon a computer program which, when executed by a set of one or more processors of a third network node, causes the third network node to perform operations of a method according to the third aspect above.

[0042] This solution allows AN-delivered multicast to be combined with the 5G control plane to enable personalized policies and charging. It also provides a common NAS (non-access stratum) stack and procedures in the 5G-RG for FWA, wired or hybrid access, with procedural changes limited to wired access stratum handling only. [Brief description of the drawings]

[0043] The present disclosure may be best understood by referring to the following description and accompanying drawings, which are used to illustrate embodiments of the invention. In the drawings:

[0044] [Figure 1] FIG. 1 illustrates the current architecture of AN or BNG-based multicast. [Diagram 2] FIG. 2 illustrates an example architecture of AN-based multicast in accordance with an embodiment of the present disclosure. [Diagram 3] FIG. 3 is a sequence diagram illustrating a call flow for shared delivery according to some embodiments of the present disclosure. [Figure 4A] FIG. 4A illustrates a current access stratum (AS) message. [Figure 4B] FIG. 4B illustrates a further type of AS message in accordance with an embodiment of the present disclosure. [Figure 4C] FIG. 4C is a diagram illustrating the contents of a multicast parameters message according to an embodiment of the present disclosure. [Diagram 5] FIG. 5 is a flow chart illustrating a method performed on a first network node according to some embodiments of the present disclosure. [Figure 6] FIG. 6 is a flow chart illustrating a method performed on a second network node according to some embodiments of the present disclosure. [Figure 7] FIG. 7 is a block diagram illustrating a method performed on a third network node according to some embodiments of the disclosure. [Figure 8] FIG. 8 is a block diagram illustrating a first network node according to some embodiments of the disclosure. [Figure 9] FIG. 9 is another block diagram illustrating a first network node according to some embodiments of the disclosure. [Figure 10] FIG. 10 is a block diagram illustrating a second network node in accordance with some embodiments of the disclosure. [Figure 11] FIG. 11 is another block diagram illustrating a second network node according to some embodiments of the disclosure. [Figure 12] FIG. 12 is a block diagram illustrating a third network node in accordance with some embodiments of the disclosure. [Figure 13] FIG. 13 is another block diagram illustrating a third network node according to some embodiments of the disclosure. [Figure 14] FIG. 14 is a block diagram illustrating a communication system according to some embodiments of the disclosure. [Figure 15] FIG. 15 is a block diagram that illustrates a schematic of a communications network connected to a host computer through an intermediate network. [Figure 16] FIG. 16 is a generalized block diagram of a host computer communicating with a user device over a partially wireless connection via a base station. [Figure 17] , [Figure 18] , [Figure 19] , [Figure 20] 17 to 20 are flow charts illustrating methods carried out in a communication system including a host computer, a base station and a user equipment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] In the following detailed description, a method and device for shared distribution of IP multicast are described. In the following detailed description, numerous specific details, such as logic implementation, types and interrelationships of system components, are described to provide a more detailed understanding of the present disclosure. However, it should be understood by those skilled in the art that the present disclosure can be implemented without such specific details. In other examples, control structures, circuits, and instruction sequences are not shown in detail so as not to obscure the present disclosure. Those skilled in the art will be able to implement the appropriate functions without undue experimentation, including the description.

[0046] References herein to "one embodiment," "embodiment," "exemplary embodiment," and the like indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments may necessarily include that particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is within the knowledge of one of ordinary skill in the art to affect such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.

[0047] Bracketed text and blocks with dashed borders (e.g., big dashes, small dashes, dot dashes, and dots) may be used herein to indicate optional actions that add additional features to embodiments of the present disclosure. However, such notations should not be construed to mean that these are the only options or optional actions, and / or that blocks with solid borders are not optional in certain embodiments of the present disclosure.

[0048] In the following detailed description and claims, the terms "coupled" and "connected," along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. "Coupled" is used to indicate that two or more elements co-operate or interact with each other, even if they may not be in direct physical or electrical contact with each other. "Connected" is used to indicate the establishment of communication between two or more elements that are coupled with each other.

[0049] An electronic device stores and transmits (internally and / or over a network with other electronic devices) code (which may be comprised of software instructions and may be referred to as computer program code or computer programs) and / or data using machine-readable media (also referred to as computer-readable media), such as machine-readable storage media (e.g., magnetic disks, optical disks, read-only memories (ROMs), flash memory devices, phase-change memories), and machine-readable transmission media (also referred to as carriers) (e.g., electrical, optical, radio, acoustic, or other forms of propagated signals, such as carrier waves, infrared signals, etc.). Thus, an electronic device (e.g., a computer) includes hardware and software, such as a set of one or more processors coupled to one or more machine-readable storage media for storing code for execution on the set of processors and / or for storing data. For example, an electronic device may comprise a non-volatile memory containing code, such that the non-volatile memory can persist code / data even when the electronic device is turned off (power is removed), and while the electronic device is turned on, that portion of the code to be executed by the processor of the electronic device is copied from the typically slower non-volatile memory to a volatile memory (e.g., dynamic random access memory (DRAM), static random access memory (SRAM)) of the electronic device. A typical electronic device further includes a set of one or more physical network interfaces for establishing network connections (for transmitting and / or receiving code and / or data using propagated signals) with other electronic devices. One or more portions of the embodiments of the present disclosure may be implemented using different combinations of software, firmware, and / or hardware.

[0050] FIG. 2 illustrates an example architecture of AN-based multicast according to an embodiment of the present disclosure.

[0051] Note that the AN can be integrated into the AGF, such that there are deployment scenarios where the AN can be 5G "aware". It is also possible to have shared distribution between the AN and the STB using a PON system.

[0052] An artifact of attempting to integrate AN-based multicast with 5GS will need to be local to the wired system to avoid complicating 5GS.

[0053] Joining and leaving a 5MBS multicast group must use procedures and concepts common to wireless access.

[0054] 5MBS for wireline will also need to support ATSSS and handover (HO) in the future, therefore maximizing alignment with 5MBS procedures should simplify the addition of this functionality.

[0055] In the future, the AGF functionality may be integrated into the Access Node (AN) which implies different implementations, so flexibility is needed in any design.

[0056] The present disclosure works in deployments where shared distribution is not available or where the AGF does not support the 5MBS procedure.

[0057] It is possible to provide support for IPoE (Internet Protocol over Ethernet) FN-RG (Fixed Network-RG) but without the full personalization that 5GS offers. This is a result of IGMP aggregation from the AN to the AGF, there is no visibility of individual FN-RGs and therefore individual subscriber management uses existing procedures.

[0058] In the broad brush aspect, the AGF has a proxy ID to request 5MBS service on behalf of the set of served FN-RGs. The AGF splices shared distribution from 5GS to the multicast VLAN to the AN. The AGF receives aggregate IGMP from the AN. The AGF gets the multicast content by performing 5MBS procedures using a proxy subscription to the 5GS. The AGF provides the shared distribution feed to the AN which replicates it to the individual RGs / STBs. The RG uses a normal PDU session to access the FCC (Fast Channel Change) server.

[0059] Deployed access nodes do not have 5G capabilities. Multicast "joins" in the AN are the result of STB initiated IGMP messages relayed by the RG. There is a leaf initiated join (LIJ) via the user plane. There is no root initiated join (RIJ) capability that allows the network to control the multicast.

[0060] IGMP can only be understood by legacy ANs if it is delivered as raw IPoE frames. Since legacy ANs only do multicast replication of IPoE frames downstream, there is no 5G metadata such as QFI or UP Session ID. However, each multicast stream has a unique multicast address.

[0061] IGMP signaling uses IP multicast addresses to identify the multicast group of interest.

[0062] Most IPTV systems are implemented as IPv4, and since access is local there has been no impetus to define an IPv6 version.

[0063] This disclosure will only refer to IGMP procedures, although MLD for IPv6 may be a perfectly valid embodiment.

[0064] Prior to 5MBS, numerous proposals were submitted to the WWC for achieving joint distribution to the AGF. A common format used a single subscriber PDU session as the shared access session for multicast, but this had very complicated procedures for a particular subscriber to select another subscriber session to leave the multicast group.

[0065] Since then, the use of IGMP from the 5G-RG and having the AGF interworking IGMP with the 5MBS has been considered. This has many issues: there is a different wired implementation than wireless (not desirable) and the AGF acting as a proxy does not have the 5G-RG authentication credentials (considered to be a showstopper).

[0066] A preferred embodiment is where the 5G RG uses 5MBS NAS procedures according to the 5MBS architecture and multicast distribution is set up, the access stratum part of the session setup (where the access specific aspects of the communication channel configuration were communicated) will indicate to the 5G-RG that supplementary procedures and different encapsulation are required to establish access to the shared distribution between the AGF and the AN. Thus, the successful response to joining the multicast group will include additional information encoded as additional information in the access stratum signaling from the AGF to the 5G-RG: 1. An indication to use IGMP (IPv4) or MLD (dIPv6) encapsulated as IPoE as an additional non-5G signaling step; 2.Multicast is delivered as IPoE and is not 5WE encapsulated.

[0067] As a prerequisite, a legacy access node (AN) is typically pre-provisioned with an access control list for a subscriber to indicate the TV channels / multicast groups that the subscriber has the right to access.

[0068] This provisioning must be coordinated with 5G system subscriber management.

[0069] FIG. 3 is a sequence diagram illustrating a call flow for shared delivery according to some embodiments of the present disclosure.

[0070] In step 1, a subscriber is provisioned with the set of multicast TV channels that he or she is allowed to view. In step 2, the list is provisioned to 5GS and legacy ANs.

[0071] In step 3, the 5G-RG receives IGMP from the Set Top Box (STB). In step 4, the 5G-RG generates a 5MBS PDU Associate Session Initiation procedure. In step 5, the 5G-RG requests multicast using a session modification using the IP multicast address obtained from IGMP. In step 6, a 5MBS shared distribution session is set up to the AGF if it does not already exist.

[0072] In step 7, the subscriber is added to the 5MBS shared distribution session at the AGF. In step 8, the AGF instructs the 5G-RG to use IGMP using AS PDU session parameters, and the session encapsulation is raw IPoE.

[0073] In step 9, the 5G-RG issues an IGMP to the multicast group.

[0074] In step 10, the AN receives the IGMP and then performs one of the following two actions: If it does not have the multicast group, issue a join upstream and add the subscriber drop as a new leaf; If it has a multicast group, add the subscriber drop as a new leaf.

[0075] In step 11, when the AGF receives a new IGMP join, it maps it to the associated 5MBS session (which should pre-exist at that time). Before adding a shared distribution to the AN, the AGF needs to check whether there is a valid client UE for the 5MBS multicast group.

[0076] Additional steps may occur in parallel with some of these procedures, such as the STB accessing a fast channel change server to pre-fill playout buffers.

[0077] In step 12, multicast distribution begins.

[0078] It will be recognized that non-5G ANs delivering multicast are simply local optimizations for access, and solutions need to accommodate both shared and individual delivery.

[0079] This allows for a desirable scenario where common procedures can be used in 5G systems and any changes to integrate non-5G components can be local to the specific access type. It is limited to access layer procedures for configuration that are purely local matter between the 5G-RG and the AGF. In the general case (AGF integrated with FWA and possibly AN), step 8 above simply indicates the multicast distribution details (individual distribution direct from the AGF) and does not indicate that additional steps (9 and 10) are required to start the multicast distribution and that there are specific protocol details to be configured (use of IPoE).

[0080] 4A is a diagram showing a current AS message. The AS message can be one of five defined TLVs (type length values).

[0081] 4B illustrates a further type of AS message according to an embodiment of the present disclosure. A sixth type of AS message includes a multiple parameter message.

[0082] 4C is a diagram illustrating the contents of a multicast parameter message according to an embodiment of the present disclosure. The multicast parameter message includes a multicast discriminator type, a multicast discriminator value, and supplementary procedures.

[0083] The multicast discriminator type indicates: 5WE (AGF / AN integration with individual distribution UPF to 5G-RG and possibly shared distribution to AN / AGF) -IPoE (AN distribution).

[0084] Multicast discriminator values ​​indicate the following: · Existing Associate PDU Session 5WE Session ID for individual delivery New 5WE Session ID for AN / AGF Integrated Shared Delivery ·IP multicast address for IPoE (AN-based shared distribution).

[0085] The auxiliary procedures show: 0 = None (individual distribution and AN / AGF integrated shared distribution) · 1 = IGMP (for AN-based shared distribution).

[0086] 5 is a flowchart illustrating a method 500 performed on a first network node according to some embodiments of the present disclosure. By way of example, but not by way of limitation, the operations of the flowchart may be performed by an RG, such as the RG of FIG. 3. The operations in this and other flowcharts are described with reference to example embodiments of other figures. However, it should be understood that the operations of the flowchart may be performed by embodiments of the present disclosure other than those discussed with reference to other figures, and that the embodiments of the present disclosure discussed with reference to these other figures may perform different operations than those discussed with reference to the flowchart.

[0087] In one embodiment, a first network node may send a first request for modifying an MBS-related PDU session to a first functional node (block 501). The first network node may receive a first acknowledgment ACK for modifying the MBS-related PDU session and an AS PDU session parameters message from a second network node (block 502).

[0088] As an example, the first functional node may be an SMF and the second network node may be an AGF.

[0089] As an example, the AS PDU session parameters message may indicate the use of IGMP and IPoE encapsulation.

[0090] As an example, the AS PDU session parameters message may be a multicast parameters message that includes a multicast discriminator type, a multicast discriminator value, and an auxiliary procedure.

[0091] As an example, the method 500 further includes: sending a second request for establishment of an MBS-related PDU session to the first functional node before sending the first request; and Receiving a second ACK for establishment of the MBS-related PDU session from the second network node.

[0092] As an example, the method 500 further includes: After receiving the first ACK, sending a third request for IGMP join to the third network node.

[0093] As a further example, the third network node may be an AN.

[0094] The present disclosure further provides a first network node adapted to perform the method 500.

[0095] 6 is a flowchart illustrating a method 600 performed on a second network node according to some embodiments of the present disclosure. As an example, the operations of the flowchart may be performed by an AGF such as the AGF of FIG.

[0096] In one embodiment, the second network node may add a subscriber to the MBS shared distribution session (block 601). The second network node may send a first ACK for modifying the MBS-related PDU session and an AS PDU session parameters message to the first network node (block 602).

[0097] As an example, the first network node may be an RG.

[0098] As an example, the AS PDU session parameters message may indicate the use of IGMP and IPoE encapsulation.

[0099] As an example, the AS PDU session parameters message may be a multicast parameters message that includes a multicast discriminator type, a multicast discriminator value, and an auxiliary procedure.

[0100] As an example, if there is no MBS shared distribution session to the second network node, an MBS shared distribution session may be established between the second network node and the second function node.

[0101] As a further example, the second functional node may be a MB-SMF.

[0102] As an example, the method 600 further includes: receiving a second ACK for establishment of the MBS-related PDU session from the first functional node; and Sending a second ACK to the first network node.

[0103] As a further example, the first functional node may be an SMF.

[0104] As an example, the method 600 further includes: receiving aggregate IGMP join requests for the multicast group from a third network node; Mapping aggregate IGMP join requests to MBS shared broadcast sessions; Checking whether there are valid clients for a multicast group; and Establishing a shared distribution session with a third network node, if one exists.

[0105] As a further example, the third network node may be an AN.

[0106] As an example, the second network node may be integrated with the AN.

[0107] Furthermore, the present disclosure provides a second network node adapted to perform the method 600.

[0108] 7 is a flow chart illustrating a method 700 performed on a third network node according to some embodiments of the present disclosure. As an example, the operations of the flow chart may be performed by an AN such as the AN of FIG.

[0109] In one embodiment, the third network node may receive an IGMP join request for a multicast group from the first network node (block 701). The third network node may add a subscriber drop as a new leaf (block 702).

[0110] As an example, the first network node may be an RG.

[0111] As an example, the method 700 further includes: If the third network node does not have the multicast group, it sends an abstract IGMP join request for the multicast group to the second network node.

[0112] As a further example, the second network node may be an AGF.

[0113] As a further example, the method 700 may further include: Receiving a second shared distribution session from a second network node.

[0114] Furthermore, the present disclosure provides a third network node adapted to perform the method 700.

[0115] Figure 8 is a block diagram illustrating a first network node 800 according to some embodiments of the present disclosure. By way of example, and not by way of limitation, the first network node 800 may operate as an RG, such as the RG of Figure 3. It should be understood that the first network node 800 may be implemented using components other than those shown in Figure 8.

[0116] 8, the first network node 800 may include at least a processor 801, a memory 802, a network interface 803, and a communication medium 804. The processor 801, the memory 802, and the network interface 803 may be communicatively coupled to each other via the communication medium 804.

[0117] Processor 801 may include one or more processing units. A processing unit may be a physical device or product that includes one or more integrated circuits that read data and instructions from a computer-readable medium, such as memory 802, and selectively execute the instructions. In various embodiments, processor 801 may be implemented in various ways. As one example, processor 801 may be implemented as one or more processing cores. As another example, processor 801 may include one or more separate microprocessors. In yet another example, processor 801 may include an application specific integrated circuit (ASIC) that provides particular functionality. In yet another example, processor 801 may provide particular functionality by using an ASIC and / or by executing computer-executable instructions.

[0118] The memory 802 may include one or more computer usable or computer readable storage media capable of storing data and / or computer executable instructions. It should be appreciated that the storage media are preferably non-transitory storage media.

[0119] The network interface 803 may be a device or product that enables the first network node 800 to transmit data to or receive data from other devices. In various embodiments, the network interface 803 may be implemented in various ways. As an example, the network interface 803 may be implemented as an Ethernet interface, a token ring network interface, a fiber optic network interface, a network interface (e.g., Wi-Fi, WiMax, etc.), or another type of network interface.

[0120] The communications medium 804 may facilitate communications between the processor 801, the memory 802, and the network interface 803. The communications medium 804 may be implemented in a variety of ways. For example, the communications medium 804 may include a Peripheral Component Interconnect (PCI) bus, a PCI Express bus, an Accelerated Graphics Port (AGP) bus, a Serial Advanced Technology Attachment (ATA) interconnect, a Parallel ATA interconnect, a Fibre Channel interconnect, a USB bus, a Small Computing System Interface (SCSI) interface, or another type of communications medium.

[0121] In the example of FIG. 8, the instructions stored in the memory 802 may include instructions that, when executed by the processor 801, cause the first network node 800 to perform the method described with respect to FIG.

[0122] 9 is another block diagram illustrating a first network node 900 according to some embodiments of the present disclosure. By way of example, and not by way of limitation, the first network node 900 may operate as an RG, such as the RG of FIG. 3. It should be understood that the first network node 900 may be implemented using components other than those shown in FIG. 9.

[0123] 9, the first network node 900 may comprise at least a sending unit 901 and a receiving unit 902. The sending unit 901 may be adapted to perform at least the operations described in block 501 of FIG. 5. The receiving unit 902 may be adapted to perform at least the operations described in block 502 of FIG. 5.

[0124] 10 is a block diagram illustrating a second network node 1000 according to some embodiments of the present disclosure. By way of example, but not limitation, the second network node 1000 may be an AGF such as the AGF of FIG. 3. It should be understood that the second network node 1000 may be implemented using components other than those shown in FIG.

[0125] 10, the second network node 1000 may include at least a processor 1001, a memory 1002, a network interface 1003, and a communication medium 1004. The processor 1001, the memory 1002, and the network interface 1003 are communicatively coupled to each other via the communication medium 1004.

[0126] The processor 1001, memory 1002, network interface 1003, and communication medium 1004 are structurally similar to the processor 801, memory 802, network interface 803, and communication medium 804, respectively, and will not be described in detail herein.

[0127] In the example of FIG. 10, the instructions stored in the memory 1002 may include instructions that, when executed by the processor 1001, cause the second network node 1000 to perform the method described in relation to FIG.

[0128] 11 is another block diagram illustrating a second network node 1100 according to some embodiments of the present disclosure. By way of example, but not limited to, the second network node 1100 may be an AGF such as the AGF of FIG. 3. It should be understood that the second network node 1100 may be implemented using components other than those shown in FIG.

[0129] 11, the second network node 1100 may include at least an additional unit 1101 and a sending unit 1102. The additional unit 1101 may be adapted to perform at least the operations described in block 601 of FIG. 6. The sending unit 1102 may be adapted to perform at least the operations described in block 602 of FIG. 6.

[0130] 12 is a block diagram illustrating a third network node 1200 according to some embodiments of the present disclosure. By way of example, and without limitation, the third network node 1200 may be an AN such as the AN of FIG. 3. It should be understood that the third network node 1200 may be implemented using components other than those shown in FIG. 12.

[0131] 12, the third network node 1200 may include at least a processor 1201, a memory 1202, a network interface 1203, and a communication medium 1204. The processor 1201, the memory 1202, and the network interface 1203 are communicatively coupled to each other via the communication medium 1204.

[0132] The processor 1201, the memory 1202, the network interface 1203, and the communication medium 1204 are structurally similar to the processor 801 or 1001, the memory 802 or 1002, the network interface 803 or 1003, and the communication medium 804 or 1004, respectively, and will not be described in detail herein.

[0133] In the example of FIG. 12, the instructions stored in the memory 1202 may include instructions that, when executed by the processor 1201, cause the third network node 1200 to perform the method described in relation to FIG.

[0134] 13 is another block diagram illustrating a third network node 1200 according to some embodiments of the present disclosure. By way of example, but not limitation, the third network node 1300 may be an AN such as the AN of FIG. 3. It should be understood that the third network node 1300 may be implemented using components other than those shown in FIG.

[0135] 13, the third network node 1300 may include at least a receiving unit 1301 and an adding unit 1302. The receiving unit 1301 may be adapted to perform at least the operations described in block 701 of FIG. 7. The adding unit 1302 may be adapted to perform at least the operations described in block 702 of FIG. 7.

[0136] The units shown in Figures 9, 11, and 13 may constitute machine-executable instructions embodied in a machine (e.g., a readable medium) that, when executed by a machine, cause the machine to perform the operations described. Any of these units may also be implemented as hardware, such as an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), etc.

[0137] Furthermore, it should be understood that the configurations described herein are given by way of example only: other configurations (e.g., more controllers or more detectors, etc.) may be used in addition to or instead of those shown, and some units may be omitted entirely. The function and cooperation of these units are explained in more detail with reference to Figures 5-7 correspondingly.

[0138] 14 is a block diagram illustrating a communication system 1400 according to some embodiments of the present disclosure. The communication system 1400 may include at least a first network node 1401, a second network node 1402, and a third network node 1403. In one embodiment, the first network node 1401 may function as a first network node 800 or 900 as shown in FIG. 8 or FIG. 9, the second network node 1402 may function as a second network node 1000 or 1100 as shown in FIG. 10 or FIG. 11, and the third network node 1403 may function as a third network node 1200 or 1300 as shown in FIG. 12 or FIG. 13. In one embodiment, the first network node 1401, the second network node 1402, and the third network node 1403 may communicate with each other.

[0139] FIG. 15 is a block diagram that illustrates a schematic of a communications network connected to a host computer through an intermediate network.

[0140] Referring to Fig. 15, according to one embodiment, a communication system includes a communication network 1510, such as a 3GPP type cellular network, including an access network 1511, such as a radio access network, and a core network 1514. The access network 1511 comprises a number of base stations 1512a, 1512b, 1512c, such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 1513a, 1513b, 1513c. Each base station 1512a, 1512b, 1512c can be connected to the core network 1514 via a wired or wireless connection 1515. A first user equipment (UE) 1591 located in the coverage area 1513c can be configured to wirelessly connect to or be paged by a corresponding base station 1512c. A second UE 1592 in the coverage area 1513a can be wirelessly connected to a corresponding base station 1512a. In this example, multiple UEs 1591, 1592 are shown, however, the disclosed embodiments are equally applicable to situations where a single UE is within the coverage area or where a single UE is connected to a corresponding base station 1512.

[0141] The communication network 1510 itself is connected to a host computer 1530, which may be implemented in hardware and / or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host computer 1530 may be under the ownership or control of a service provider, or may be operated by or on behalf of the service provider. The connection 1521, 1522 between the communication network 1510 and the host computer 1530 may extend directly from the core network 1514 to the host computer 1530, or may extend through any intermediate network 1520. The intermediate network 1520 may be a combination of one or more of a public network, a private network, or a host network, if any, the intermediate network 1520 may be a backbone network or the Internet, and in particular the intermediate network 1520 may include two or more sub-networks (not shown).

[0142] The communication system of FIG. 15 generally provides connectivity between one of the connected UEs 1591, 1592 and a host computer 1530. Such connectivity may be described as an over-the-top (OTT) connection 1550. The host computer 1530 and the connected UEs 1591, 1592 are configured to communicate data and / or signaling via the OTT connection 1550 using the access network 1511, the core network 1514, any intermediate networks 1520, and possibly further infrastructure (not shown) as intermediaries. The OTT connection 1550 may be transparent in the sense that participating communication devices through which the OTT connection 1550 passes are unaware of the routing of the uplink and downlink communications. For example, the base station 1512 may not be or need not be informed about the past routing of an incoming downlink communication having data originating from the host computer 1530 that is forwarded (e.g., handed over) to the connected UE 1591. Similarly, the base station 1512 does not need to know the future routing of an outgoing uplink communication from the UE 1591 to the host computer 1530.

[0143] With reference to Fig. 16, an implementation example according to the embodiment of the UE, base station and host computer described in the previous paragraph will be described below. In the communication system 1600, the host computer 1610 comprises hardware 1615 including a communication interface 1616 configured to set up and maintain wired or wireless connections with interfaces of different communication devices of the communication system 1600. The host computer 1610 further comprises a processing circuit 1618, which may have storage and / or processing capabilities. In particular, the processing circuit 1618 may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. The host computer 1610 further comprises software 1611, which is stored in or accessible by the host computer 1610 and executable by the processing circuit 1618. The software 1611 includes a host application 1612. The host application 1612 may be operable to provide services to a remote user, such as a UE 1630, connecting via an OTT connection 1650 that terminates at the UE 1630 and the host computer 1610. In providing services to the remote user, the host application 1612 may provide user data that is transmitted using the OTT connection 1650.

[0144] The communication system 1600 further includes a base station 1620 provided within the communication system and comprising hardware 1625 enabling communication with the host computer 1610 and the UE 1630. The hardware 1625 may include a communication interface 1626 for setting up and maintaining wired or wireless connections with interfaces of different communication devices of the communication system 1600, and a wireless interface 1627 for setting up and maintaining at least a wireless connection 1670 with a UE 1630 located within a coverage area (not shown in FIG. 16) served by the base station 1620. The communication interface 1626 may be configured to facilitate a connection 1660 to the host computer 1610. The connection 1660 may be direct or may pass through a core network (not shown in FIG. 16) of the communication system and / or one or more intermediate networks external to the communication system. In the illustrated embodiment, the hardware 1625 of the base station 1620 further includes processing circuitry 1628, which may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. The base station 1620 further includes software 1621, either stored internally or accessible via an external connection.

[0145] The communication system 1600 may further include the UE 1630, whose hardware 1635 may include a wireless interface 1637 configured to set up and maintain a wireless connection 1670 with a base station serving a coverage area in which the UE 1630 is currently located. The hardware 1635 of the UE 1630 further includes a processing circuit 1638, which may comprise one or more programmable processors, application specific integrated circuits, field programmable gate arrays, or combinations thereof (not shown) adapted to execute instructions. The UE 1630 further includes software 1631 stored within or accessible to the UE 1630 and executable by the processing circuit 1638. The software 1631 includes a client application 1632. The client application 1632 may be operable to provide services to a human or non-human user via the UE 1630 with the support of the host computer 1610. At the host computer 1610, an executing host application 1612 may communicate with an executing client application 1632 via the UE 1630 and an OTT connection 1650 that terminates at the host computer 1610. In providing services to a user, the client application 1632 may receive request data from the host application 1612 and provide user data in response to the request data. The OTT connection 1650 may transport both the request data and the user data. The client application 1632 may interact with the user to generate the user data that it provides.

[0146] Note that the host computer 1610, the base station 1620, and the UE 1630 shown in Fig. 16 may be the same as the host computer 1530, one of the base stations 1512a, 1512b, and 1512c, and one of the UEs 1591 and 1592 in Fig. 15, respectively. That is, the internal operations of these entities may be as shown in Fig. 16, and independently, the surrounding network topology may be that of Fig. 15.

[0147] 16, an OTT connection 1650 is depicted abstractly to show communication between a host computer 1610 and a user equipment 1630 via a base station 1620, without explicitly referring to any intermediate devices and the exact routing of messages through those devices. The network infrastructure may determine the routing, which may be configured to be hidden from the UE 1630, or from the service provider operating the host computer 1610, or both. The network infrastructure may further decide to dynamically change the routing while the OTT connection 1650 is active (e.g., based on load considerations or network reconfiguration).

[0148] The wireless connection 1670 between the UE 1630 and the base station 1620 follows the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of the OTT service provided to the UE 1630 using the OTT connection 1650 of which the wireless connection 1670 forms the final segment. More precisely, the teachings of these embodiments may improve the efficiency of radio resource utilization, thereby providing benefits such as reduced user latency.

[0149] Measurement procedures may be provided for the purpose of monitoring data rates, latencies, and other factors that one or more embodiments improve upon. There may further be optional network functionality to reconfigure the OTT connection 1650 between the host computer 1610 and the UE 1630 in response to changes in the measurement results. The measurement procedures and / or network functionality to reconfigure the OTT connection 1650 may be implemented in the software 1611 of the host computer 1610, or in the software 1631 of the UE 1630, or both. In an embodiment, a sensor (not shown) may be located in or associated with a communication device through which the OTT connection 1650 passes. The sensor may participate in the measurement procedure by providing values ​​of monitored quantities, as exemplified above, or other physical quantities from which the software 1611, 1631 may calculate or estimate the monitored quantities. Reconfiguration of the OTT connection 1650 may include message formats, retransmission configurations, preferred routing, etc., and such reconfiguration need not impact the base station 1620 and may be unknown or imperceptible to the base station 1620. Such procedures and functions are known in the art and may be implemented. In certain embodiments, the measurements may include proprietary UE signaling to facilitate the host computer 1610 measuring throughput, propagation time, latency, etc. The measurements may be performed in having the software 1611, 1631 send messages (particularly null or "dummy" messages) using the OTT connection 1650 while monitoring propagation times, errors, etc.

[0150] FIG. 17 is a flow chart illustrating a method performed in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be described with reference to FIG. 15 and FIG. 16. To simplify the disclosure, only drawing references to FIG. 17 are included in this section. In a first step 1710 of the method, the host computer provides user data. In an optional sub-step 1711 of the first step 1710, the host computer provides the user data by executing a host application. In a second step 1720, the host computer initiates a transmission carrying the user data to the UE. In an optional third step 1730, the base station transmits the user data carried in the host computer initiated transmission to the UE according to the teachings of the embodiments described throughout this disclosure. In an optional fourth step 1740, the UE executes a client application associated with the host application executed by the host computer.

[0151] FIG. 18 is a flow chart illustrating a method performed in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be described with reference to FIG. 15 and FIG. 16. To simplify the disclosure, only drawing references to FIG. 18 are included in this section. In a first step 1810 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides the user data by executing a host application. In a second step 1820, the host computer initiates a transmission carrying the user data to the UE. The transmission may pass through a base station in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step 1830, the UE receives the user data carried in the transmission.

[0152] FIG. 19 is a flow chart illustrating a method performed in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be described with reference to FIG. 15 and FIG. 16. To simplify the disclosure, only drawing references to FIG. 19 are included in this section. In an optional first step 1910 of the method, the UE receives input data provided by the host computer. Additionally or alternatively, in an optional second step 1920, the UE provides user data. In an optional sub-step 1921 of the second step 1920, the UE provides the user data by executing a client application. In an optional sub-step 1911 of the first step 1910, the UE executes a client application that provides the user data in response to the received input data provided by the host computer. In providing the user data, the executed client application may further take into account user input received from a user. Regardless of the particular manner in which the user data was provided, the UE initiates transmission of the user data to the host computer in an optional third sub-step 1930. In a fourth step 1940 of the method, the host computer receives user data transmitted from UE2 according to the teachings of the embodiments described throughout this disclosure.

[0153] FIG. 20 is a flow chart illustrating a method performed in a communication system according to one embodiment. The communication system includes a host computer, a base station, and a UE, which may be described with reference to FIG. 15 and FIG. 16. To simplify the disclosure, only drawing references to FIG. 20 are included in this section. In an optional first step 2010 of the method, the base station receives user data from the UE, according to the teachings of the embodiments described throughout this disclosure. In an optional second step 2020, the base station initiates transmission of the received user data to the host computer. In a third step 2030, the host computer receives the user data carried in the transmission initiated by the base station.

[0154] Some portions of the preceding detailed description are presented in terms of algorithms and symbolic representations of transactions on data bits within a computer memory. These algorithmic descriptions and representations are the methods used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is herein generally conceived to be a self-consistent sequence of transactions leading to a desired result. The transactions are those transactions requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of public usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.

[0155] It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless otherwise apparent from the above discussion, throughout the description, discussions utilizing terms such as "processing" or "computing" or "calculating" or "determining" or "displaying" will be understood to refer to the actions and processes of a computer system or similar electronic computing device that manipulate and transform data represented as physical (electronic) quantities in the computer system's registers and memory to other data also represented as physical quantities in the computer system's memory or registers, or other such information storage, transmission or display devices.

[0156] The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct a more specialized apparatus to perform the required method transactions. The required structure for a variety of these systems will be apparent from the above description. In addition, embodiments of the present disclosure are not described with reference to any particular programming language. It will be understood that a variety of programming languages ​​can be used to implement the teachings of the embodiments of the present disclosure described herein.

[0157] An embodiment of the present disclosure may be a manufacture in which a non-transitory machine-readable medium (such as a microelectronic memory) stores instructions (e.g., computer code) that program one or more data processing components (collectively referred to herein as "processors") to perform the operations described above. In other embodiments, some of these operations may be performed by specific hardware components that include hardwired logic (e.g., dedicated digital filter blocks and state machines). These operations may alternatively be performed by any combination of programmed data processing components and fixed hardwired circuitry components.

[0158] In the foregoing detailed description, embodiments of the present disclosure have been described with reference to certain exemplary embodiments thereof. It will be apparent that various modifications may be made thereto without departing from the spirit and scope of the present disclosure as set forth in the following claims. The specification and drawings are therefore to be regarded in an illustrative rather than a restrictive sense.

[0159] Throughout the description, some embodiments of the present disclosure are presented through flow diagrams. It should be understood that the transactions and order of transactions depicted in these flow diagrams are intended for illustrative purposes only and are not intended as limitations of the present disclosure. Those skilled in the art will recognize that changes can be made to the flow diagrams without departing from the spirit and scope of the present disclosure, as set forth in the following claims.

Claims

1. A method (500) performed by a first network node, said method comprising: Sending (501) a first request for modification of an MBS (Multicast Broadcast Service) related PDU (Packet Data Unit) session to a first functional node; receiving (502) a first acknowledgment for the modification of the MBS-related PDU session and an AS (Access Stratum) PDU Session Parameters message from a second network node; A method comprising:

2. 2. The method of claim 1 , The AS PDU Session Parameters message indicates the use of IGMP (Internet Group Management Protocol) and IPoE (Internet Protocol over Ethernet) encapsulation.

3. 3. The method according to claim 1 or 2, The AS PDU Session Parameter Message is a Multicast Parameter Message including a Multicast Discriminator Type, a Multicast Discriminator Value, and an Auxiliary Procedure.

4. 4. The method according to any one of claims 1 to 3, sending a second request for establishing the MBS-related PDU session to the first functional node before sending the first request; receiving a second acknowledgment for the establishment of the MBS-related PDU session from the second network node; The method further comprises:

5. 5. The method according to any one of claims 1 to 4, The method further comprising sending a third request for IGMP join to a third network node after receiving the first acknowledgment.

6. 6. The method according to any one of claims 1 to 5, The method, wherein the first network node is a residential gateway, the first functional node is a session management function, and the second network node is an access gateway function.

7. A method (600) performed by a second network node, said method comprising: Adding a subscriber to a Multicast Broadcast Service (MBS) shared distribution session (601); Sending (602) a first acknowledgement for a change of MBS-related PDU (Packet Data Unit) session and an AS (Access Stratum) PDU Session Parameters message to a first network node; A method comprising:

8. 8. The method of claim 7, The AS PDU Session Parameters message indicates the use of IGMP (Internet Group Management Protocol) and IPoE (Internet Protocol over Ethernet) encapsulation.

9. 9. The method according to claim 7 or 8, The AS PDU Session Parameter Message is a Multicast Parameter Message including a Multicast Discriminator Type, a Multicast Discriminator Value, and an Auxiliary Procedure.

10. 10. The method according to any one of claims 7 to 9, comprising: If there is no MBS sharing distribution session to the second network node, the MBS sharing distribution session is established between the second network node and a second function node.

11. 11. The method according to any one of claims 7 to 10, comprising: receiving a second acknowledgement for the establishment of the MBS-related PDU session from a first functional node; transmitting the second acknowledgment to the first network node; and The method further comprises:

12. 12. The method according to any one of claims 7 to 11, comprising: receiving an aggregate IGMP join request for the multicast group from a third network node; Mapping the aggregated IGMP join request to the MBS shared broadcast session; checking whether there are valid clients for the multicast group; if present, establishing a shared broadcast session with the third network node; The method further comprises:

13. 12. The method according to any one of claims 7 to 11, comprising: A method according to claim 1, wherein the second network node is integrated with a third network node that is an access node.

14. 14. The method according to any one of claims 7 to 13, comprising: The method, wherein the second network node is an access gateway function and the first network node is a residential gateway.

15. A method (700) performed by a third network node, said method comprising: Receiving an Internet Group Management Protocol (IGMP) join request for multiple groups from a first network node (701); Adding a subscriber drop as a new leaf (702); A method comprising:

16. 16. The method of claim 15, The method further comprising: if the third network node does not have the multicast group, sending an aggregate IGMP join request for the multiple groups to a second network node.

17. 17. The method of claim 16, The method further comprising receiving a shared broadcast session from the second network node.

18. 18. The method according to any one of claims 15 to 17, comprising: The method, wherein the third network node is an access node and the first network node is a residential gateway.

19. A first network node (800), A processor (801); A memory (802) communicatively coupled to the processor and configured to store instructions that, when executed by the processor, cause the first network node to perform the operations of the method of any one of claims 1 to 6; A first network node comprising:

20. A first network node configured to perform the method according to any one of claims 1 to 6.

21. A second network node (1000), A processor (1001), a memory (1002) communicatively coupled to the processor and configured to store instructions that, when executed by the processor, cause the second network node to perform the operations of the method of any one of claims 7 to 14; A second network node comprising:

22. A second network node configured to perform the method according to any one of claims 7 to 14.

23. A third network node (1200), A processor (1201), a memory (1202) communicatively coupled to the processor and configured to store instructions that, when executed by the processor, cause the third network node to perform the operations of the method of any one of claims 15 to 18; A third network node comprising:

24. A third network node configured to carry out the method of any one of claims 15 to 18.

25. A communication system (1400), A first network node (1401) according to claim 19 or 20, A second network node (1402) according to claim 21 or 22, in communication with at least the first network node; A third network node (1403) according to claim 23 or 24, in communication with at least the first network node and the second network node; 23. A communication system comprising:

26. A non-transitory computer readable medium having stored thereon a computer program which, when executed by a set of one or more processors of a first network node, causes the first network node to perform the operations of the method according to any one of claims 1 to 6.

27. A non-transitory computer readable medium having stored thereon a computer program which, when executed by a set of one or more processors of a second network node, causes the second network node to perform the operations of the method according to any one of claims 7 to 14.

28. A non-transitory computer readable medium having stored thereon a computer program which, when executed by a set of one or more processors of a third network node, causes the third network node to perform the operations of the method of any one of claims 15 to 18.

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