Patent Publication Number: US-2022225059-A1

Title: Method, system and apparatus of multicast communication

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of priority under 35 U.S.C. § 120 as a continuation of PCT Patent Application No. PCT/CN2019/109282, filed on Sep. 30, 2019, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The disclosure relates generally to enabling one to many multicast communication in a 5G wireless network. In particular, the disclosure relates to methods of multicast group management in the 5G Core (5GC) network. 
     BACKGROUND 
     In the 3GPP Release 16 specifications, the 5G wireless network supports the 5G virtual network (VN) group communication. 5G VN group communication includes one to one communication, and also one to many communication. One to one communication supports forwarding of unicast traffic between two User Equipment (UEs) within a 5G VN, or between a UE and a device on the Data Network (DN). One to many communication supports forwarding of broadcast traffic from one UE (or device on the DN) to all other UEs (or device on the DN) within a 5G VN , or multicast traffic from one UE (or device on the DN) to some UEs (or device on the DN) within a 5G VN. 
     However, currently there is no support for one to many multicast communication in 3GPP Release 16 specifications. There is a need to find a solution to resolve the issue of supporting one to many 5G VN multicast communication. 
     SUMMARY 
     The example embodiments disclosed herein are directed to solving the issues relating to one or more of the problems presented in the prior art, as well as providing additional features that will become readily apparent by reference to the following detailed description when taken in conjunction with the accompany drawings. In accordance with various embodiments, example systems, methods, devices and computer program products are disclosed herein. It is understood, however, that these embodiments are presented by way of example and are not limiting, and it will be apparent to those of ordinary skill in the art who read the present disclosure that various modifications to the disclosed embodiments is made while remaining within the scope of this disclosure. 
     In one embodiment, an example wireless communication method to enable multicast operation includes: querying, by a first wireless communication node, a second wireless communication node to receive one or more multicast group member information. The method further includes receiving, by the first wireless communication node, the one or more multicast group member information from the second wireless communication node, and configuring, by the first wireless communication node, one or more third wireless communication nodes with the one or more multicast group member information received from the second wireless communication node, to set up rules for multicast packet forwarding at the one or more third wireless communication nodes. 
     In another embodiment, a wireless communication method to provision multicast operation in a wireless network, includes: receiving, by the second wireless communication node, a provisioning message from a fourth wireless communication node wherein the provisioning message includes the multicast group member information, and provisioning, by the second wireless communication node, the multicast group member information into a data repository. 
     In yet another embodiment, a wireless communication method to provision multicast operation in a wireless network includes: receiving, by the fourth wireless communication node, a provisioning message from a fifth wireless communication node wherein the provisioning message includes the multicast group member information; and provisioning, by the fourth wireless communication node, the multicast group member information into a data repository. 
     In yet another embodiment, a method for enabling multicast operation in a wireless network, includes: receiving, by a first wireless communication node, a group management protocol message from a second wireless communication node, and forwarding, by the first wireless communication node, the group management protocol message to a third wireless communication node. 
     The above and other aspects and their implementations are described in greater detail in the drawings, the descriptions, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various example embodiments of the present disclosure are described in detail below with reference to the following figures or drawings. The drawings are provided for purposes of illustration only and merely depict example embodiments of the present disclosure to facilitate the reader&#39;s understanding of the present disclosure. Therefore, the drawings should not be considered limiting of the breadth, scope, or applicability of the present disclosure. It should be noted that for clarity and ease of illustration, these drawings are not necessarily drawn to scale. In the drawings, similar symbols typically identify similar components, unless dictated otherwise. 
         FIG. 1  illustrates an example 5G VN topology in which techniques and other aspects disclosed herein may be implemented, in accordance with an embodiment of the present disclosure. 
         FIG. 2  illustrates the operation of one to many broadcast communication in the example 5G VN network of  FIG. 1 , in accordance with an embodiment of the present disclosure. 
         FIG. 3  illustrates the operation of one to many multicast communication in the example 5G VN network of  FIG. 1  to contrast multicast communication from broadcast communication depicted in  FIG. 2 , in accordance with an embodiment of the present disclosure. 
         FIG. 4A  illustrates a message sequence diagram of an example method to provision one to many multicast communication in the various nodes of the 5G Core network in the example of  FIG. 1 , according to yet another example embodiment of the present disclosure. 
         FIG. 4B  depicts a message sequence diagram of how various nodes of the 5G Core network interact with each other to utilize the provisioning of  FIG. 4A  to enable one to many multicast communication in the 5G network, according to an example embodiment of the present disclosure. In particular,  FIG. 4B  depicts how the Session Management Function (SMF) obtains the multicast group information and configures the User Plane Function (UPF). 
         FIG. 5A  illustrates a message sequence diagram depicting a different method of enabling one to many multicast operation in the 5G VN of  FIG. 1 , according to an embodiment in which the UE and DN are capable of handling Multicast group management protocol. 
         FIG. 5B  depicts a message sequence diagram about the interactions between various components of the 5G Core network to detect the group management message and enable one to many multicast communication, according to an example embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Overview of Multicast Operation in 5G Network 
     Various example embodiments of the present disclosure are described below with reference to the accompanying figures to enable a person of ordinary skill in the art to make and use the present disclosure. As would be apparent to those of ordinary skill in the art, after reading the present disclosure, various changes or modifications to the examples described herein is made without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the example embodiments and applications described and illustrated herein. Additionally, the specific order or hierarchy of steps in the methods disclosed herein are merely example approaches. Based upon design preferences, the specific order or hierarchy of steps of the disclosed methods or processes is re-arranged while remaining within the scope of the present disclosure. Thus, those of ordinary skill in the art will understand that the methods and techniques disclosed herein present various steps or acts in a sample order, and the present disclosure is not limited to the specific order or hierarchy presented unless expressly stated otherwise. 
     In the following description, the terms “5G wireless network” and “mobile network” are used interchangeably. Also, the terms “DN” and “a device in the DN” are used interchangeably. 
     Referring to  FIG. 1 , an example 5G VN network  100  is illustrated for a 5G system. The VN group consists of UE- 1  (reference numeral  152 ), UE- 2  ( 154 ), UE- 3  ( 156 ) and UE- 4  ( 158 ) in multiple Next Generation Base Stations (gNBs  142 ,  144 ,  146  and  148 ) belonging to 5G Radio Access Network (RAN), as well as a Device-A ( 132 ) in the DN ( 130 ). The VN group consisting of the group members and related Protocol Data Unit (PDU) sessions and 5GC network entities comprise a 5G VN network. The UE- 1   152  and UE- 2   154  establish the PDU session to UPF- 1   122 , which is the PDU session anchor (PSA) for UE- 1   152  and UE- 2   154  in the example embodiment. The UE- 3   156  and UE- 4   158  establish the PDU session to UPF- 2   124 , which is the PSA for UE- 3   156  and UE- 4   158  in the example. A dedicated SMF  110  is responsible for configuring all the PDU sessions for communication between members of a certain 5G VN group. The SMF  110  establishes N19 interface  170  between PSA UPF- 1  and PSA UPF- 2  for VN group N19 forwarding. Also shown in  FIG. 1  is a N6 interface  160  between the Device-A  132  and the UPF- 1   122 . In the following disclosure and figures, the example topology of  FIG. 1  shall be used to illustrate examples of operation of any member of 5G VN group sending data to any other member of VN group (unicast), or all the other members of VN group (broadcast), or subset of all the other member of VN group (multicast). 
     Referring now to  FIG. 2 , an example of 5G VN broadcast communication is shown to differentiate it from multicast communication described later. The UE- 1  sends VN group broadcast traffic by sending the packet  205  with a broadcast destination address. The data is first sent to PSA UPF- 1  via PDU session of UE- 1 . To enable broadcast communication, it is assumed that the SMF has provisioned PSA UPF- 1  and PSA UPF- 2  with related packet detection rule (PDR) and forwarding action rule (FAR) for 5G VN broadcast forwarding corresponding to the broadcast destination address used by UE- 1 . Actions by the PSA UPF- 1  include: send packet to Device-A via N6 interface  210  (so called N6 forwarding), send packet to UE- 2  via UE- 2  PDU session  214  (so called local switch), and send packet to PSA UPF- 2  via N19 interface  212  (so called N19 forwarding). Actions by the PSA UPF- 2  include: send packet to UE- 3  via UE- 3  PDU session  216 , and send packet to UE- 4  via UE- 4  PDU session  218 . Thus, to achieve broadcast communication, the PSA UPF- 1  sends three (3) copies of received packet to interfaces N6, N19 and UE- 2  separately, the PSA UPF- 2  sends two (2) copies of received packet to UE- 3  and UE- 4  separately. 
     In the case of 5G VN unicast communication, the UE sends VN group unicast traffic by sending the packet with unicast destination address (i.e. remote address). The data is first sent to PSA UPF via PDU session of UE. The PSA UPF may send via N6 interface (if the remote end is in the DN), or via N19 interface (if the remote end is under the peer UPF), or via local switch (if the remote end is under the same PSA UPF). 
     Referring to  FIG. 3 , in the example case of 5G VN multicast, a particular multicast group may be a subset of the whole 5G VN group member. For example, in  FIG. 3 , the Virtual group member are UE- 1 , UE- 3  and UE- 4  in 5G network and Device-A in the DN. The UE- 1 , UE- 3  and Device-A are the member of multicast group A (UE- 1 , UE- 3 , Device-A), the UE- 3  and Device-A are the member of multicast group B (UE- 3 , Device-A), the UE- 1  and UE- 4  are the member of multicast group C (UE- 1 , UE- 4 ). Every multicast group is identified by a particular multicast address. If the UE- 1  send the data packet  305  which destination address is set to multicast group A address, the packet will be send to UE- 3  via N19 interface  314  and sent to Device-A via N6 interface  312 . To enable support for one to many multicast communication in the 5G wireless network, some means have to be provided for the network know who the members of each multicast group are (which is associated with a unique multicast address), and where in the 5G network the multicast member is in, so that the multicast packet can be forwarded to each member using the correct interface and service (i.e., message). 
     Embodiment #1 
     In a fixed network (as opposed to a 5G wireless network or a mobile network), devices typically support Internet Group Management Protocol (IGMP) or Multicast Listener Discovery (MLD) for multicast communication. In a mobile network (e.g. 5G system), the IGMP or MLD are typically not supported due to UE capability or due to network complexity. Thus, in the first embodiment of the 5G network of the present disclosure, neither the UE nor the 5G network provides inherent support for multicast group management protocols. 
     Referring now to  FIG. 4A , in one embodiment of the present disclosure, support is provided for multicast communication by provisioning the multicast group information from the Application Function (AF)  402  to the Network Exposure Function (NEF)  404 . The multicast group information includes 5G VN group ID, one or more multicast group member identities, and the multicast address. 
     The NEF provision group member information to Unified Data Management (UDM)  406 , by using a modified version of the Nudm_ParameterProvision service that includes the multicast group information. The 5G VN group ID can be the external group ID or internal group ID (if NEF  404  has the mapping between these two IDs. In some embodiment, the NEF  404  checks with UDM  406  for translating the external group ID to internal Group ID), the group member identity could be GPSI, multicast address can be IP multicast address or MAC multicast address. 
     In one embodiment, the NEF  404  provisions group member information to the Packet Control Function (PCF)  406 , with a new service being required for PCF  406 . The UDM or PCF then provision group member information to Unified Data Repository (UDR)  408 . The UDR is a repository of subscriber information (or subscription information, or policy information, among other data) and can be used to service a number of network functions. In some embodiments, the NEF  404  provisions group member information to UDR  408  directly. To UDR  408 , the group member identity could be GPSI or SUPI (Subscription Permanent Identifier). The translation form GPSI to SUPI may be performed by UDM or PCF  406 . 
     The SMF  450  obtains the multicast group member information from UDR  408 . The SMF  450  analyzes the multicast group member information to configure all the involved UPFs  452  with related PDR and FAR. The involved UPFs are the ones that act as PDU session anchors for the one or more UEs and Devices in the DN that are mentioned in the multicast group member information. The message sequence diagram of  FIG. 4A  depicts the following steps: 
     At step  101 , the AF  402  provision the multicast group information to NEF  404 . The multicast group information includes 5G VN group ID, one or more multicast group member identities, and the multicast address. 
     At step  102 , the NEF  404  provision the multicast group information to UDM or PCF  406 . 
     At step  103 , the UDM or PCF  406  provision the multicast group information to UDR  408 . Note: In one embodiment, the NEF  404  provisions the multicast group information to UDR  408  directly. 
     Now referring to  FIG. 4B , a message sequence diagram is depicted regarding how the SMF  450  obtains the multicast group member information from the UDR  408 , and configures all the involved UPFs  452  to enable multicast communication in the 5G Core network. The steps depicted in the message sequence diagram are: 
     At step  201 , the SMF  450  either requests or subscribes for the multicast group member information from the UDM or PCF  406 . If SMF  450  uses the request/response mechanism, the API/message is Nudm_SDM_Get, whereas if SMF  450  uses the subscribe/notify mechanism, the API/message is Nudm_SDM_subscribe. If SMF  450  uses the PCF  406  to receive the multicast group member information, then a new PCF service has to be used for that purpose. 
     At step  202 , he UDM or PCF  406  query the UDR  408  for the multicast group information. The multicast group information includes 5G VN group ID, one or more multicast group member identities, and the multicast address. The service/messages used at this step is Nudr_DM_query service. 
     At step  203 , the UDM or PCF  406  either send a response message or notify the SMF  450  with multicast group member information. If SMF  450  uses the request/response mechanism, the API/message is output of Nudm_SDM_Get. On the other hand, if SMF  450  uses the subscribe/notify mechanism, the API/message is Nudm_SDM_notification. 
     At step  204 , the SMF configure the involved UPF with related PDR and FAR. The involved UPF(s) includes the UPF which is involved in the related multicast group data forwarding using the N 4  session Establishment/Modification request. 
     Embodiment #2 
     In another embodiment, the UE and 5G network support the Multicast group management protocol, while the 5G network does not support Multicast Routing protocol. In such an embodiment, the present disclosure provides a method for the 5G network to use its own feature to support multicast routing. 
     Referring now to  FIG. 5A , a second embodiment of a method of enabling one to many multicast operation in the example 5G VN of  FIG. 1  is illustrated. The various steps in the sequence diagram of  FIG. 5A  are: 
     At step  301 , the UE  502  sends the Group Management Protocol message  621  (e.g join message, or leave message) in the PDU session. The message indicate the multicast address that the UE want to join or leave. 
     At step  302 , the UPF detects the Group Management Protocol message  623  from UE  502  and sends it to SMF  508 . 
     At step  303 , the SMF  508  calculates the multicast group topology (i.e., SMF  508  figures out all the involved UPFs  510 ) and configures the involved UPFs  510  with related PDR and FAR. The involved UPF(s)  510  includes all the UPF which is involved in the related multicast group data forwarding. 
     At step  304 , the SMF  508  send the Group Management Protocol message  629  to UPF  506 . 
     At step  305 , the UPF  506  send the Group Management Protocol message to DN (data network) and/or UE  512 . 
     Referring now to  FIG. 5B , a message sequence diagram about the interactions between various components of the 5G Core network to detect the group management message and enable one to many multicast communication is depicted, the individual steps in the method being: 
     At step  401 , the UPF  610  receives the Group Management Protocol message from DN  652 . 
     At step  402 , the UPF  610  detects the Group Management Protocol message from DN  652  and sends it to SMF  608 . 
     At step  403 , the SMF  608  calculates the multicast group topology (i.e., SMF  608  figures out all the involved UPFs  606 ) and configures the involved UPFs  606  with related PDR and FAR. The involved UPF(s) includes all the UPF which is involved in the related multicast group data forwarding. 
     At step  404 , the SMF  608  sends the Group Management Protocol message to UPF  606 . 
     At step  405 , the UPF  606  sends the Group Management Protocol message to UE  602 . 
     While various embodiments of the present disclosure have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. Likewise, the various diagrams may depict an example architectural or configuration, which are provided to enable persons of ordinary skill in the art to understand example features and functions of the present disclosure. Such persons would understand, however, that the disclosure is not restricted to the illustrated example architectures or configurations, but is implemented using a variety of alternative architectures and configurations. Additionally, as would be understood by persons of ordinary skill in the art, one or more features of one embodiment is combined with one or more features of another embodiment described herein. Thus, the breadth and scope of the present disclosure should not be limited by any of the above-described illustrative embodiments. 
     It is also understood that any reference to an element herein using a designation such as “first,” “second,” and so forth does not generally limit the quantity or order of those elements. Rather, these designations is used herein as a convenient means of distinguishing between two or more elements or instances of an element. Thus, a reference to first and second elements does not mean that only two elements is employed, or that the first element must precede the second element in some manner. 
     Additionally, a person having ordinary skill in the art would understand that information and signals is represented using any of a variety of different technologies and techniques. 
     A person of ordinary skill in the art would further appreciate that any of the various illustrative logical blocks, modules, processors, means, circuits, methods and functions described in connection with the aspects disclosed herein is implemented by electronic hardware (e.g., a digital implementation, an analog implementation, or a combination of the two), firmware, various forms of program or design code incorporating instructions (which is referred to herein, for convenience, as “software” or a “software module), or any combination of these techniques. To clearly illustrate this interchangeability of hardware, firmware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware, firmware or software, or a combination of these techniques, depends upon the particular application and design constraints imposed on the overall system. Skilled artisans can implement the described functionality in various ways for each particular application, but such implementation decisions do not cause a departure from the scope of the present disclosure. 
     Furthermore, a person of ordinary skill in the art would understand that various illustrative logical blocks, modules, devices, components and circuits described herein is implemented within or performed by an integrated circuit (IC) that can include a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, or any combination thereof. The logical blocks, modules, and circuits can further include antennas and/or transceivers to communicate with various components within the network or within the device. A general purpose processor is a microprocessor, but in the alternative, the processor is any conventional processor, controller, or state machine. A processor can also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other suitable configuration to perform the functions described herein. 
     If implemented in software, the functions is stored as one or more instructions or code on a computer-readable medium. Thus, the steps of a method or algorithm disclosed herein is implemented as software stored on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that is enabled to transfer a computer program or code from one place to another. A storage media is any available media that is accessed by a computer. By way of example, and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that is used to store desired program code in the form of instructions or data structures and that is accessed by a computer. 
     In this document, the term “module” as used herein, refers to software, firmware, hardware, and any combination of these elements for performing the associated functions described herein. Additionally, for purpose of discussion, the various modules are described as discrete modules; however, as would be apparent to one of ordinary skill in the art, two or more modules may be combined to form a single module that performs the associated functions according embodiments of the present disclosure. 
     Additionally, memory or other storage, as well as communication components, may be employed in embodiments of the present disclosure. It will be appreciated that, for clarity purposes, the above description has described embodiments of the present disclosure with reference to different functional units and processors. However, it will be apparent that any suitable distribution of functionality between different functional units, processing logic elements or domains may be used without detracting from the present disclosure. For example, functionality illustrated to be performed by separate processing logic elements, or controllers, may be performed by the same processing logic element, or controller. Hence, references to specific functional units are only references to a suitable means for providing the described functionality, rather than indicative of a strict logical or physical structure or organization. 
     Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein is applied to other implementations without departing from the scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein, but is to be accorded the widest scope consistent with the novel features and principles disclosed herein, as recited in the claims below.