Patent Description:
An example of Internet Protocol (IP) Multimedia Subsystem (IMS) architecture is defined in <NUM>rd Generation Partnership Project (3GPP) Technical Specification (TS) <NUM>. The IMS architecture can interwork with evolved packet core (EPC) and 3GPP <NUM>th Generation (<NUM>, also called New Radio or NR) Core (5GC) when it comes to Multimedia Telephony (e.g., Voice over Long Term Evolution LTE (VOLTE)). In Multimedia Telephony, there are different user plane (UP) functions in charge of managing the voice/video traffic/IP packets (e.g., real-time transport protocol (RTP) packets). These functions are placed in different hops in the network and are selected by different IMS functions, e.g., proxy call session control function (P-CSCF) selects an access media gateway (A-MGW/ATGW) so that the voice media sent by the user's user equipment (UE, also called wireless device or WD) traverse this gateway. A media gateway control function (MGCF) also selects a media gateway (MGW, also called IP multimedia gateway or IM-MGW) when interworking with the circuit switched (CS) domain. Additionally, when voice media or announcements are to be sent from the network, an IMS application server (IMS-AS, acting as a media resource function controller (MRFC) can select an MRFP (media resource function processor) which, similarly to MGWs, can manage the voice packets in the uplink and downlink direction (i.e., from/to the UE).

<FIG> and <FIG> show how an example MGW selection may be performed and in which IMS network functions (NFs) the example MGW selection may be performed. With such an arrangement, in order to select a proper MGW in IMS, the configuration of the different parameters (H. <NUM> IP addresses, codecs supported, transcoding support, dual-tone multi-frequency (DTMF)/telephone-events supported, etc.) must be performed in all the IMS nodes deployed, which may include media gateway controllers (e.g., P-CSCF, access transfer control function (ATCF), Multimedia Telephony application server (MMTEL-AS), MGCF). Each time a new software upgrade is performed in an MGW (e.g., to support a new voice or video codec), all the affected IMS nodes are then re-configured to have the most up to date information. During scale out procedures, if a new MGW is instantiated in the network, again, all the IMS nodes are re-configured to have the whole set of information for the new MGW. This consumes network resources.

In addition, it may be desirable to select an MGW near the geographical area where the UE is camping on. Hence, the existing configuration may allow additional options to select the closest MGW. However, this further complicates the operations and maintenance (O&M) of the whole network because the cell identifiers (cell IDs) or geographical area information is very large (i.e., exceeds a predetermined area threshold), and may be consistent across all the IMS NFs the whole time.

Document 3GPP TS <NUM> V17. <NUM> may be construed to disclose the Stage <NUM> system architecture for the <NUM> System. The <NUM> System provides data connectivity and services. The document covers both roaming and non-roaming scenarios in all aspects, including interworking between 5GS and EPS, mobility within 5GS, QoS, policy control and charging, authentication and in general <NUM> System wide features e.g. SMS, Location Services, Emergency Services.

Document 3GPP TS <NUM> V16. <NUM> may be construed to disclose the Stage <NUM> procedures and Network Function Services for the <NUM> system architecture which is described in the TS <NUM> and for the policy and charging control framework which is described in TS <NUM>.

Some embodiments advantageously provide methods and apparatuses for media gateway dynamic discovery in IMS.

According to the present disclosure, there are provided methods, computer-readable media and network nodes. Further developments are set forth in the dependent claims.

In one aspect, some embodiments of the present disclosure provide arrangements to include new functionality in e.g., 3GPP according to one or more of the following:.

In some embodiments, the specific information for one or more of these new types of NFs are also part of the NF's profile. Non-limiting examples of this new NF profile information for the new NF types include one or more of:.

In some embodiments, IMS nodes (especially the 5GC (service-based interface) SBI capable nodes, e.g., P-CSCF, IMS-AS, etc.) and/or any NF nodes are configured to discover MGWs in the network by reusing the existing NRF services. In some embodiments, IMS nodes and/or any NF nodes may also subscribe to MGW NF profile changes, so that when an MGW/media function configuration is updated or introduced at the MGW, all the subscribed IMS nodes and/or any subscribed NF nodes are notified immediately about it and may act accordingly, such as reconfiguring themselves with the updated information.

In some embodiments, an NRF is provisioned/configured with the MGW/media function information in a first step (e.g., 3GPP may allow the NRF to be provisioned with the new NFs' information via O&M); this does not preclude that the MGW can register its profile in NRF by using existing NRF services defined in 5GC.

One or more of the embodiments described herein may have one or more of the following advantages:.

Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to media gateway dynamic discovery in IMS. Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

The UE herein can be any type of wireless device capable of communicating with a network node or another UE over radio signals. In some embodiments, the UE may be an autonomous machine configured to communicate via IMS. The UE herein can by any type of communication device capable of communicating with another UE, an application server (AS), a network node, a server, an IMS NF or other IMS network node, via a wired connection and/or a wireless connection. The UE may also be a radio communication device, target device, device to device (D2D) UE, machine type UE or UE capable of machine to machine communication (M2M), low-cost and/or low-complexity UE, a sensor equipped with UE, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a Narrowband IoT (NB-IOT) device etc..

In some embodiments, the term "node" is used herein and can be any kind of network node, such as, NRF node, NF node, IMS node, AF node, etc. In some embodiments, a node can be a Proxy-Call Session Control Function (P-CSCF) node, a mobility management node (e.g., Mobility Management Entity (MME) and/or Access and Mobility Function (AMF)), a gateway node (e.g., access gateway), a session management node (e.g., session management function (SMF) node), a user plane function (UPF) node, an AS node or any network node. In some embodiments, the network node may be, for example, a subscriber database node (e.g., unified data repository (UDR), home subscriber server (HSS)), a core network node, a Fifth Generation (<NUM>) and/or New Radio (NR) network node, an Evolved Packet System (EPS) node, an Internet Protocol (IP) Multimedia Subsystem (IMS) node, an Serving-CSCF node, an Interrogating-CSCF node, a network repository function (NRF) node, a unified data management (UDM) node, a Network Exposure Function (NEF) node, a home subscriber server (HSS) node, a home location register (HLR) node, etc..

In yet other embodiments, the network node may include any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), relay node, integrated access and backhaul (IAB), donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. The term "radio node" used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node.

In some other embodiments, the term NF node can be and/or comprise a P-CSCF node, a media NF type node (i.e., an NF associated with processing/handling/transferring/routing of media and/or any other process step associated with media and/or media type communication, e.g., a media type communication for a UE), an A-MGW, an ATGW, IM-MGW, IWK-MGW, an MGCF, IMS-AS, an MRF, etc. However, the NF node is not limited as such and may be and/or comprise any type of node. Further, a media NF type node may refer to one or more of a P-CSCF node (and/or any CSCF node), an A-MGW, an ATGW, IM-MGW, IWK-MGW, an MGCF, IMS-AS, an MRF, any other node described herein, etc..

In some embodiments, a Third Generation Partnership Project (3GPP) core network (e.g., 5GC) may include a Service Based Architecture (SBA) in which Network Functions (NFs) provide one or more services to one or more service consumers. This can be performed, for example, via Hyper Text Transfer Protocol/Representational State Transfer (HTTP/REST), application programming interfaces (APIs), etc. Generally, the various services may be considered self-contained functionalities that can be changed and modified in an isolated manner without affecting other services. Furthermore, the services may include various service operations, which may be more granular divisions of the overall service functionality. In some embodiments, in order to access a service, both the service name and the targeted service operation is to be indicated. The interactions between service consumers and service producers may be, for example, a "request/response" or "subscribe/notify" type or yet other types of interactions.

In some embodiments, one or more of the nodes described herein may be more generally considered and/or comprise an application function (AF) and may be referred to as an AF node. For example, the NRF node, NF node, IMS node, described herein may be more generally referred to as AF node.

In some embodiments, the various AF nodes and NF nodes that may be described herein may be referred to by their function names and/or more generally as network nodes and/or nodes.

A node described herein may include physical components, such as processors, allocated processing elements, or other computing hardware, computer memory, communication interfaces, and other supporting computing hardware. The node may use dedicated physical components, or the node may be allocated use of the physical components of another device, such as a computing device or resources of a datacenter, in which case the node may be said to be virtualized. A node may be associated with multiple physical components that may be located either in one location, or may be distributed across multiple locations.

An indication generally may explicitly and/or implicitly indicate the information it represents and/or indicates. Implicit indication may for example be based on position and/or resource used for transmission. Explicit indication may for example be based on a parametrization with one or more parameters, and/or one or more index or indices corresponding to a table, and/or one or more bit patterns representing the information.

In some embodiments, the term "media" may indicate video, voice over IP, circuit switched voice call, etc..

Although some embodiments are described with reference to an NRF, it should be understood that the principles of the present disclosure may also be applied to an NF that operates the same or substantially similar to the NRF, i.e., allowing NFs to discover the services offered by other NFs and/or subscribing to NFs.

Note also that some embodiments of the present disclosure may be supported by standard documents disclosed in Third Generation Partnership Project (3GPP) technical specifications. That is, some embodiments of the description can be supported by the above documents. In addition, all the terms disclosed in the present document may be described by the above standard documents.

Note that although terminology from one particular wireless system, such as, for example, <NUM>rd Generation Partnership Project (3GPP), Long Term Evolution (LTE), <NUM>th Generation (<NUM>) and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation 3GPP 6th Generation (<NUM>) or later Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure.

Note further, that functions described herein as being performed by a NRF node, NF node described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

With that being said, it should be understood that, in some embodiments, the names used may not be limited to the specific names used herein, which may be exemplary and/or descriptive since it may be given another name in a technical specification, such as a 3GPP Technical Specification (TS) even though the use/function is as disclosed in the present disclosure.

Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in <FIG> a schematic diagram of a communication system <NUM>, according to one embodiment, constructed in accordance with the principles of the present disclosure. The communication system <NUM> in <FIG> is a non-limiting example and other embodiments of the present disclosure may be implemented by one or more other systems and/or networks. Referring to <FIG>, system <NUM> includes a NRF node <NUM> and a NF node <NUM>. In some embodiments, the NF node <NUM> may be any IMS node. In some embodiments, the NF node <NUM> may be any of the NFs discussed herein.

It should be understood that the system <NUM> may include numerous nodes of those shown in <FIG>, as well as additional nodes not shown in <FIG>. In addition, the system <NUM> may include many more connections/interfaces than those shown in <FIG>.

The system <NUM> may include one or more nodes having a media function information (MFI) unit <NUM>, a media function discovery (MFD) unit <NUM> and a media function subscription (MFS) unit <NUM>.

In one embodiment, NRF node <NUM> includes a MFI unit <NUM> which is configured to cause the network node to: receive a discovery request from a first network function (NF) node, the discovery request indicating at least one media-related information associated with a user equipment (UE); discover at least one second NF node based at least in part on the media-related information; and send a discovery response to the discovery request, the discovery response indicating the discovered at least one second NF node.

In another embodiment, NF node <NUM> includes an MFD unit <NUM> and an MFS unit <NUM>, which is configured to cause the network node to: send a discovery request, the discovery request indicating at least one media-related information associated with a user equipment (UE); and receive a discovery response to the discovery request, the discovery response indicating at least one second NF node, the at least one second NF node being discovered based at least in part on the media-related information.

Example implementations, in accordance with some embodiments, of NFR node <NUM> and NF node <NUM>, which may include any of the devices/nodes discussed herein and will now be described with reference to <FIG>.

The NRF node <NUM> includes a communication interface <NUM>, processing circuitry <NUM>, and memory <NUM>. The communication interface <NUM> may be configured to communicate with other elements in the system <NUM> according to some embodiments of the present disclosure. In some embodiments, the communication interface <NUM> may be formed as or may include, for example, one or more radio frequency (RF) transmitters, one or more RF receivers, and/or one or more RF transceivers, and/or may be considered a radio interface. In some embodiments, the communication interface <NUM> may also include a wired interface.

The processing circuitry <NUM> may include one or more processors <NUM> and memory, such as, the memory <NUM>. In particular, in addition to a traditional processor and memory, the processing circuitry <NUM> may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor <NUM> may be configured to access (e.g., write to and/or read from) the memory <NUM>, which may comprise any kind of volatile and/or non-volatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory).

Thus, the NRF node <NUM> may further include software stored internally in, for example, memory <NUM>, or stored in external memory (e.g., database) accessible by the NRF node <NUM> via an external connection. The software may be executable by the processing circuitry <NUM>. The processing circuitry <NUM> may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by the NRF node <NUM>. The memory <NUM> is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software may include instructions stored in memory <NUM> that, when executed by the processor <NUM> and/or media function information (MFI) unit <NUM>, causes the processing circuitry <NUM> and/or configures the NRF node <NUM> to perform the processes described herein with respect to the NRF node <NUM> (e.g., processes described with reference to <FIG> and/or any of the other figures).

The NF node <NUM> includes a communication interface <NUM>, processing circuitry <NUM>, and memory <NUM>. The communication interface <NUM> may be configured to communicate with any of the nodes in the system <NUM> according to some embodiments of the present disclosure. In some embodiments, the communication interface <NUM> may be formed as or may include, for example, one or more radio frequency (RF) transmitters, one or more RF receivers, and/or one or more RF transceivers, and/or may be considered a radio interface. In some embodiments, the communication interface <NUM> may also include a wired interface.

Thus, the NF node <NUM> may further include software stored internally in, for example, memory <NUM>, or stored in external memory (e.g., database) accessible by the NF node <NUM> via an external connection. The software may be executable by the processing circuitry <NUM>. The processing circuitry <NUM> may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., NF node <NUM>. The memory <NUM> is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software may include instructions stored in memory <NUM> that, when executed by the processor <NUM> and/or media function discovery (MFD) unit <NUM> and/or media function subscription (MFS) unit <NUM> causes the processing circuitry <NUM> and/or configures the NF node <NUM> to perform the processes described herein with respect to the NF node <NUM> (e.g., processes described with reference to <FIG> and/or any of the other figures).

In <FIG>, the connection between the devices NF node <NUM> and NRF node <NUM> is shown without explicit reference to any intermediary devices or connections. However, it should be understood that intermediary devices and/or connections may exist between these devices, although not explicitly shown.

Although <FIG> shows various "units", such as MFI unit <NUM>, MFD unit <NUM>, MFS unit <NUM>, as being within a respective processor, it is contemplated that these elements may be implemented such that a portion of the elements is stored in a corresponding memory within the processing circuitry. In other words, the elements may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

In some embodiments, the inner workings of the NRF node <NUM> and NF node <NUM> from <FIG> may be as shown in <FIG> and independently, the surrounding network topology may be that of <FIG> and/or 7A and/or 7B and/or 7C, where the NF node <NUM> may be any of the nodes shown in <FIG> and/or 7A and/or 7B and/or 7C.

<FIG> is a flowchart of an example process in NRF node e.g., NRF node <NUM> according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by the NRF node <NUM> may be performed by one or more elements of NRF node <NUM> such as MFI unit <NUM> in processing circuitry <NUM>, memory <NUM>, processor <NUM>, communication interface <NUM>, etc. according to the example process/method. The example process includes receiving (Block S100), such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, a discovery request from a first network function (NF) node, the discovery request indicating at least one media-related information associated with a user equipment, UE. The method includes discovering (Block S102), such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, at least one second NF node based at least in part on the media-related information. The method includes sending (Block S104), such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, a discovery response to the discovery request, the discovery response indicating the discovered at least one second NF node.

In some embodiments, the discovered at least one second NF node comprises a media NF type node. In some embodiments, the media NF type node is one of an access media gateway (A-MGW), an Internet Protocol (IP) multi-media gateway (IM-MGW), and a media resource function (MRF). In some embodiments, the requesting first NF node is an Internet Protocol (IP) multimedia subsystem (IMS) node. In some embodiments, the IMS node is one of a proxy call session control function (P-CSCF) node, a media gateway control function (MGCF) node and an IMS application server (IMS-AS) node. In some embodiments, the discovery request indicating the at least one media-related information is received as a result of a message that indicates a request for a media type communication for the UE and wherein the discovered at least one second NF node is selected to serve the media type communication for the UE.

In some embodiments, the at least one media-related information associated with the UE comprises a location information for the UE, a media type requested by the UE and at least one codec supported by the UE. In some embodiments, the location information for the UE comprises a cell identifier associated with UE and network provided location information (NPLI) for the UE. In some embodiments, the at least one media-related information associated with the UE at least one of: is based on information in a session initiation protocol (SIP) message from the UE; is based on information in a SIP INVITE message; is based on information in a P-Access-Network-Info (PANI) SIP header; and/or comprises a target media NF type node that the at least one second NF node is requesting to be discovered to serve the UE.

In some embodiments, discovering the at least one second NF node further comprises discovering, such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, the at least one second NF node having profile information corresponding to the media-related information associated with the UE. In some embodiments, discovering the at least one second NF node having profile information corresponding to the media-related information comprises at least one of: discovering the at least one second NF node having profile information indicating support for at least one codec supported by the UE; discovering the at least one second NF node having profile information indicating a location proximity to the UE; and/or discovering the at least one second NF node having profile information indicating a media NF type node that is requested by the first NF node for the UE.

In some embodiments, the network node comprises a network repository function, NRF. In some embodiments, the network node is provisioned with profile information for at least one NF node in the at least one second NF node. In some embodiments, at least one NF node in the at least one second NF node requests to register profile information to the network node. In some embodiments, the method further includes receiving, such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, a subscription request to be notified about one of an addition of a new media NF type node and a profile information update of an existing media NF type node; and sending, such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, a notification upon detection of the one of the addition and the profile information update.

<FIG> is a flowchart of an example process in a NF or AF node e.g., NF node <NUM> according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by the NF node <NUM> may be performed by one or more elements of NF node <NUM> such as by MFD unit <NUM>, MFS unit <NUM> in processing circuitry <NUM>, memory <NUM>, processor <NUM>, communication interface <NUM>, etc. according to the example process/method. The example process includes sending (Block S106), such as via MFD unit <NUM>, MFS unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM>, and/or communication interface <NUM>, a discovery request, the discovery request indicating at least one media-related information associated with a user equipment, UE. The method includes receiving (Block S108), such as via MFD unit <NUM>, MFS unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM>, and/or communication interface <NUM>, a discovery response to the discovery request, the discovery response indicating at least one second NF node, the at least one second NF node being discovered based at least in part on the media-related information.

In some embodiments, the discovered at least one second NF node comprises a media NF type node. In some embodiments, the media NF type node is one of an access media gateway (A-MGW), an Internet Protocol (IP) multi-media gateway (IM-MGW), and a media resource function (MRF). In some embodiments, the network node is an Internet Protocol (IP) multimedia subsystem (IMS) node. In some embodiments, the IMS node is one of a proxy call session control function (P-CSCF) node, a media gateway control function (MGCF) node and an IMS application server (IMS-AS) node. In some embodiments, the discovery request indicating the at least one media-related information is sent as a result of a message that indicates a request for a media type communication for the UE and wherein the discovered at least one second NF node is selected to serve the media type communication for the UE.

In some embodiments, the at least one media-related information associated with the UE comprises a location information for the UE, a media type requested by the UE and at least one codec supported by the UE. In some embodiments, the location information for the UE comprises a cell identifier associated with UE and network provided location information (NPLI) for the UE. In some embodiments, the at least one media-related information associated with the UE at least one of: is based on information in a session initiation protocol (SIP) message from the UE; is based on information in a SIP message is a SIP INVITE message; is based on information in a P-Access-Network-Info (PANI) SIP header; and/or comprises a target media NF type node that the network node is requesting to be discovered to serve the UE.

In some embodiments, the at least one second NF node is discovered based at least in part on the at least one second NF node having profile information corresponding to the media-related information associated with the UE. In some embodiments, the at least one second NF node is discovered based at least in part on at least one of: the at least one second NF node having profile information indicating support for at least one codec supported by the UE; the at least one second NF node having profile information indicating a location proximity to the UE; and the at least one second NF node having profile information indicating a media NF type node that is requested by the network node for the UE.

In some embodiments, the discovery request is sent to a network repository function, NRF, node. In some embodiments, profile information for at least one NF node in the at least one second NF node is provisioned to the NRF node. In some embodiments, profile information for at least one NF node in the at least one second NF node is registered to the NRF node. In some embodiments, the method further includes sending, such as via MFD unit <NUM>, MFS unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM>, and/or communication interface <NUM>, a subscription request to be notified about one of an addition of a new media NF type node and a profile information update of an existing media NF type node; and receiving, such as via MFD unit <NUM>, MFS unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM>, and/or communication interface <NUM>, a notification upon detection of the one of the addition and the profile information update.

<FIG> is a flowchart of another example process in NRF node e.g., NRF node <NUM> according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by the NRF node <NUM> may be performed by one or more elements of NRF node <NUM> such as MFI unit <NUM> in processing circuitry <NUM>, memory <NUM>, processor <NUM>, communication interface <NUM>, etc. according to the example process/method. The method includes receiving (Block S110), such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, a discovery request from a first network function (NF) node 14a to discover at least one media NF type node, the discovery request indicating a media NF type of the at least one media NF type node 14b. The media NF type is one of an access media gateway (A-MGW), an Internet Protocol (IP) multi-media gateway (IM-MGW), and a media resource function (MRF). The method further includes discovering (Block S112), such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, the at least one media NF type node 14b; and transmitting (Block S114), such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>, a discovery response to the discovery request. The discovery response indicates the discovered at least one media NF type node 14b and at least one corresponding NF profile. The at least one corresponding NF profile comprise at least one of one or more media types, one or more supported codecs, and transcoding support information.

In some embodiments, the first NF node 14a is an Internet Protocol (IP) multimedia subsystem (IMS) node.

In some other embodiments, the IMS node is one of a proxy call session control function (P-CSCF) node, a media gateway control function (MGCF) node and an IMS application server (IMS-AS) node.

In one embodiment, the discovery request further indicates at least one of the one or more media types, the one or more supported codecs, and the transcoding support information required to be supported by the at least one media NF type node 14b, and discovering the at least one media NF type node further comprises discovering the at least one media NF type node supporting the at least one of one or more media types, one or more supported codecs, and transcoding support information indicated in the discovery request.

In another embodiment, the discovery request further indicates location information for the UE, the location information for the UE including at least one of a cell identifier associated with UE and network provided location information, NPLI, for the UE.

In some embodiments, the at least one corresponding NF profile further comprises one or more H. <NUM> capabilities.

In one embodiment, discovering the at least one media NF type node 14b further comprises discovering the at least one media NF type node 14b having profile information corresponding to at least one parameter indicated in the discovery request.

In another embodiment, at least one of: the network node comprises a network repository function, NRF, node <NUM>; and the network node is provisioned with at least one NF profile corresponding to the at least one media NF type node 14b.

In some embodiments, the method further includes, such as via MFI unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM> and/or communication interface <NUM>,receiving a subscription request to be notified about one of an added media NF type node and an NF profile update of an existing media NF type node; and transmitting a notification upon detection of the one of the added media NF type node and the NF profile update.

<FIG> is a flowchart of another example process in a network node, e.g., NF node <NUM> according to some embodiments of the present disclosure. One or more Blocks and/or functions and/or methods performed by the NF node <NUM> may be performed by one or more elements of NF node <NUM> such as by MFD unit <NUM>, MFS unit <NUM> in processing circuitry <NUM>, memory <NUM>, processor <NUM>, communication interface <NUM>, etc. according to the example process/method. The example process includes transmitting (Block S116), such as via MFD unit <NUM>, MFS unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM>, and/or communication interface <NUM>, a discovery request to trigger a discovery of at least one media NF type node 14b. The discovery request indicates a media NF type of the at least one media NF type node 14b. The media NF type is one of an access media gateway (A-MGW), an Internet Protocol (IP) multi-media gateway (IM-MGW), and a media resource function (MRF); and receiving (Block S118), such as via MFD unit <NUM>, MFS unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM>, and/or communication interface <NUM>, a discovery response to the discovery request. The discovery response indicates a discovered at least one media NF type node 14b and at least one corresponding NF profile. The at least one corresponding NF profile comprises at least one of one or more media types, one or more supported codecs, and transcoding support information.

In one embodiment, the discovery request is transmitted as a result of a message that indicates a request for a media type communication for a UE, and the discovered at least one media NF type node 14b is selected to serve the media type communication for the UE.

In some embodiments, the message that indicates the request for the media type communication for the UE is any one of: a session initiation protocol (SIP) message from the UE; a SIP invite message; and the SIP invite message including a P-Access-Network-Info (PANI) SIP header.

In some other embodiments, the at least one corresponding NF profile further comprises one or more H. <NUM> capabilities.

In one embodiment, the discovered at least one media NF type node 14b has profile information corresponding to at least one parameter indicated in the discovery request.

In another embodiment, at least one of: the discovery request is transmitted to another network node comprising a network repository function (NRF) node <NUM>; the discovery response is received from the other network node; and the other network node is provisioned with at least one NF profile corresponding to the at least one media NF type node 14b.

In some embodiments, the method further includes, such as via MFD unit <NUM>, MFS unit <NUM>, processing circuitry <NUM>, memory <NUM>, processor <NUM>, and/or communication interface <NUM>, transmitting, to the other network node, a subscription request to be notified about one of an added media NF type node and an NF profile update of an existing media NF type node; and receiving, from the other network node, a notification upon detection of the one of the added media NF type node and the NF profile update.

Having generally described arrangements for media gateway dynamic discovery in IMS, a more detailed description of some of the embodiments are provided as follows with reference to <FIG> and <FIG>, and which may be implemented by one or more NF nodes14 (e.g., IMS node, P-CSCF node, IMS-AS node, MGCF node, or any NF node configured to discover, subscribe to and otherwise utilize the services of the NRF) and the NRF node <NUM>.

<FIG>, <FIG>, and <FIG> illustrate an example call flow arrangement according to some embodiments of the present disclosure. Although <FIG> is described as a continuation of the call flow diagram of <FIG>, and <FIG> is described as a continuation of the call flow diagram of <FIG> and/or 7B any one of the steps S200-S240 may be performed in any order and/or be dependent/independent from any other step.

The example arrangement may include one or more of the following (each of P-CSCF (i.e., NF 14a), A-MGW (i.e., NF 14b), MGCF (i.e., NF 14c), IM-MGW (i.e., NF 14d), IMS-AS (i.e., NF 14e), MRF (i.e., NF 14f) may be a NF node <NUM>):
Step S200 of <FIG>. NRF <NUM> is provisioned with new NF profile information associated to new NF types, which may be referred to herein as media NF types and which may include one or more of A-MGW, IM-MGW, MRF). The profile information contains specific information to be consumed by the IMS NFs, such as one or more of the following media-related information:.

P-CSCF (i.e., NF 14a) receives a new (e.g., packet data unit/PDU) session establishment for a voice call, e.g., from a UE. The UE (i.e., session establishment) indicates the codecs supported and preferred, together with the access network information (e.g., cell ID). For example, the UE sends a session initiation protocol (SIP) invite message (via a radio access network (RAN), such as a gNB). The SIP invite message may include a "P-Access-Network-Info" (PANI) indicating the cell ID (e.g., cell ID identifying the cell used by the UE and being associated with the RAN). The SIP message may further include information about a media type, list of audio codecs supported, etc., which may be comprised in a session description protocol (SDP) within the SIP message.

After ensuring that the information is correct (possibly retrieving the access network information from the network via network provided location information (NPLI)), P-CSCF (i.e., NF 14a) uses the information in a PANI header (which may be a type of SIP header) to discover A-MGWs (i.e., NF 14b) close/proximate to the UE and supporting the codecs offered by the UE. For example, P-CSCF (i.e., NF 14a) sends a discovery request to NRF <NUM> comprising criteria/information (e.g., location information for the UE, codecs offered by the UE, media NF type, etc.).

NRF <NUM> searches and selects the NF profiles satisfying the criteria/information in the discovery message, e.g., close to UE location and/or supporting the codecs offered by the UE. The NF type of the selected NF profiles should match the requested NF type (e.g., A-MGW) and the rest of information (e.g., codecs, UE location information).

NRF <NUM> returns the matched NF profiles with all the information provisioned, e.g., cell IDs/areas served by the A-MGW (i.e., NF 14b), codecs, etc. For example, the NRF <NUM> sends a discovery response indicating the matched NF profiles. In some embodiments, NRF <NUM> may return only A-MGWs (i.e., NF 14b) serving cell IDs/areas that are the same as the cell ID in the PANI or the NLPI.

After caching the NF profiles received (to avoid subsequent discoveries if there is a local match against the cached NF profiles), in step S212, P-CSCF (i.e., NF 14a) selects a A-MGW (i.e., NF 14b) based on the information received and other standard NF profile information present (e.g., priority, capacity, as defined in 3GPP TS <NUM>).

<FIG> and <FIG> illustrate the continuation of the call flow diagram introduced in <FIG>, as follows:.

In some embodiments, at any point in time after the caching of the NF profiles, the IMS NFs <NUM> may subscribe to NF profile changes for the e.g., NF profile instances cached or all the MGWs (i.e., NFs <NUM>) in the network (to be notified when a new MGW is deployed or updated in the network).

One or more of the following abbreviations may be used herein:.

Claim 1:
A method in a network node (<NUM>), the method comprising:
receiving (S110) a discovery request from a first network function, NF, node (14a) to discover at least one media NF type node, the discovery request indicating:
a media NF type of the at least one media NF type node (14b), the media NF type being one of an access media gateway, A-MGW, an Internet Protocol, IP, multi-media gateway, IM-MGW, and a media resource function, MRF; and
at least one of one or more supported codecs and transcoding support information by the media NF type;
discovering (S112) the at least one media NF type node (14b) based on the at least one of the one or more supported codecs and transcoding support information by the media NF type; and
transmitting (S114) a discovery response to the discovery request, the discovery response indicating the discovered at least one media NF type node (14b) and at least one corresponding NF profile, the at least one corresponding NF profile comprising at least one of one or more media types, one or more supported codecs, and transcoding support information.