EMERGENCY CALLS IN IOPS

Background

[0001] Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features, and advantages of the enclosed embodiments will be apparent from the following description.

[0002] Mission Critical (MC) communication services are essential for the work performed by public safety users e.g. police and fire brigade. The MC communications service requires preferential handling compared to normal telecommunication services including handling of prioritized MC calls for emergency and imminent threats. Furthermore, the MC communication services require several resilience features that provide a guaranteed service level even if part of the network or backhaul infrastructure fails.

[0003] The most commonly used communication method for public safety users is Group Communication (GC), which requires delivery of the same information to multiple users. One type of GC is Push to Talk (PTT) service. A GC system can be designed with a centralized architecture approach, in which a centralized GC control node provides full control of all group data e.g. group membership, policies, user authorities, and prioritizations. Such an approach requires a network infrastructure that provides high network availability. This type of operation is sometimes known as Trunked Mode Operation (TMO) or on-network operation.

[0004] Third Generation Partnership Project (3GPP) based networks supporting GC services or Mission Critical (MC) services like Mission Critical Push To Talk (MCPTT) are specified in 3GPP Technical Specification (TS) 23.280 v16.3.0 and 3GPP TS 23.379 v16.3.0. Other MC services are also specified. For example,

Mission Critical Video (MCVideo) is specified in 3GPP TS 23.281 v16.3.0 and Mission Critical Data (MCData) is specified in 3GPP TS 23.282 v16.3.0.

[0005] Each MC service supports several types of communications amongst the users (e.g. group call, private call). There are several common functions and entities (e.g. group, configuration, identity) which are used by the MC services. The common functional architecture, described in 3GPP TS 23.280 v16.3.0, to support MC services comprises a central MC service server connected to the network providing full control of the MC service data, and MC service client(s) operating on a User Equipment(s) (UE(s)) providing MC service communications support. The MC service UE primarily obtains access to a MC service via the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) using the Evolved Packet System (EPS) architecture defined in 3GPP TS 23.401 v16.3.0.

[0006] If a MC service UE is going out of the network coverage, it can attempt to switch to the off-network mode of operation to make use of Proximity Services (ProSe) as specified in 3GPP TS 23.303 v15.1.0. ProSe provides support for the off-network operation based on a direct communication with another UE without direct support from the network. In this case, the MC service clients operating on the UEs are controlling and providing the MC service communication. For that, all the configuration data (which is similar to but normally a subset of the configuration data for an on-network operation) must be pre-provisioned to each UE.

[0007] In a 3GPP based network that provides MC services, the MC services can be guaranteed even in the case of backhaul failure by using the feature known as Isolated E-UTRAN Operations for Public Safety (IOPS) described in 3GPP TS 23.401 v16.3.0 Annex K. The IOPS functionality provides local connectivity to the public safety users’ devices that are within the communication range of an E-UTRAN radio base station(s) (eNB(s)) that supports IOPS, i.e. one or more lOPS-capable eNBs. The lOPS-capable eNB(s) is co-sited with a local Evolved Packet Core (EPC) which is used during the IOPS mode of operation. The local EPC may include the following functional entities: Mobility Management Entity (MME), Serving Gateway (S-GW), Packet Data Network Gateway (P-GW), and Home Subscriber Server (HSS).

[0008] The IOPS EPS system, i.e. the lOPS-capable eNB(s) and the local EPC, can be used in different types of deployments. One common scenario is when radio base station is located on a remote location (e.g. an island) and the radio base station is connected to the macro core network via e.g. a microwave link. If there is a microwave link failure, it is critical for Public Safety users to be able to at least have local connectivity for the communication between the users in the coverage of the lOPS-capable eNBs.

Figure 1

[0009] When the IOPS mode of operation is initiated, e.g. due to a backhaul link failure, the public safety/MC users should be able to begin being served by the IOPS EPS network. The support of MC services in the IOPS mode of operation is being specified in 3GPP TS 23.180 (currently in TS 23.180 v0.3.0). As described in Figure 2.1-1 of TS 23.180, which is reproduced herein as Figure 1, the IOPS MC system is represented by a functional model that includes an IOPS MC connectivity function and an IOPS distribution function. The UE includes an MC service client and an IOPS connectivity client to support MC services in the IOPS mode of operation.

[0010] In the IOPS mode of operation, the MC services can be supported based on an off-network like operation, where the IOPS MC system only provides Internet Protocol (IP) connectivity for the communication among the MC users. Thus, the MC services are directly provided by the MC service clients, but the corresponding MC service IP packets are transmitted over the IOPS EPS network to the IOPS connectivity function. The IOPS MC connectivity function, which is co-located with the IOPS EPS, distributes those IP packets to the targeted MC user(s) over the IOPS EPS network. This functionality is defined in 3GPP TS 23.180 as the IP connectivity functionality.

[0011] Based on the IP connectivity functionality, the IOPS MC system, via the IOPS MC connectivity function, enables MC users operating on the UEs to be registered and discovered in the IOPS mode of operation. The IOPS MC system, via the IOPS distribution function, provides IP connectivity for the MC service communication among the MC users. This means that the IOPS MC system distributes IP packets received from an MC user targeting one or more MC users. For the case of IP packets related to group communications, e.g. IP packets targeting multiple users in a group call, the IOPS MC system can distribute them to the targeted users over unicast and/or multicast transmissions over the IOPS EPS network.

[0012] 3GPP TS 23.180 also includes procedures describing how MC users are discovered by the IOPS MC system based on the publication of user information via an IOPS discovery request. Within the IOPS discovery request, an MC user includes IP connectivity information, e.g. the MC UE’s IP address assigned by the IOPS EPS. The IOPS MC system, via the IOPS connectivity function, indicates to the MC user the success or not of the IOPS discovery request. If the IOPS discovery request is accepted by the IOPS connectivity function, the MC user is registered as discovered.

Summary

[0013] There currently exist certain challenge(s). The support of MC services in the IOPS mode of operation is being specified in Release 17 3GPP TS 23.180. The IOPS mode of operation should include supporting emergency calls (private and group calls). Therefore, mechanisms are still needed to specify how emergency calls are supported in the IOPS mode of operation.

[0014] Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. The proposed solutions define mechanisms to be implemented in the IOPS mode of operation to support emergency calls, for private and/or group calls. [0015] There are, proposed herein, various embodiments which address one or more of the issues disclosed herein.

[0016] Certain embodiments may provide one or more of the following technical advantage(s). For example, embodiments of the solution(s) described herein define a new mechanism that enables the I OPS MC system to define a user (e.g., a UE) in an emergency state. Hence, the IOPS MC system serves the user with a higher (or the highest) priority for any communication based on the IP connectivity functionality.

[0017] One embodiment is directed to a method performed by a wireless communication device (208) indicating an emergency state while operating in an isolated radio access network mode of operation, the method comprising: sending (300), to a connectivity function (214) of an isolated radio access network system, a discovery request that comprises an indication that the wireless communication device (208) is in an emergency state; and receiving (304) a discovery response from the connectivity function (214).

Brief Description of the Drawings

[0018] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in a constitute a part of this application, illustrate certain non-limiting embodiments of inventive concepts. In the drawings:

Figure 1 illustrates an IOPS MC system that is represented by a functional model that includes an IOPS MC connectivity function and an IOPS distribution function;

Figure 2 illustrates one example of an IOPS MC system 200 in which embodiments of the present disclosure may be implemented;

Figure 3 illustrates an example of a discovery procedure for the MC service UE 208 in the IOPS mode of operation;

Figure 4 is a schematic block diagram of a network 400 according to some embodiments of the present disclosure;

Figure 5 is a schematic block diagram that illustrates a virtualized embodiment of the network node 400 according to some embodiments of the present disclosure;

Figure 6 is a schematic block diagram of the network node 400 according to some other embodiments of the present disclosure;

Figure 7 is a schematic block diagram of a wireless communication device 700 according to some embodiments of the present disclosure;

Figure 8 is a schematic block diagram of the wireless communication device 700 according to some other embodiments of the present disclosure. Detailed Description

[0019] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0020] Radio Node: As used herein, a “radio node” is either a radio access node or a wireless communication device.

[0021] Radio Access Node: As used herein, a “radio access node” or “radio network node” or “radio access network node” is any node in a Radio Access Network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB) in a Third Generation Partnership Project (3GPP) Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB) in a 3GPP Long Term Evolution (LTE) network), a high-power or macro base station, a low-power base station (e.g., a micro base station, a pico base station, a home eNB, or the like), a relay node, a network node that implements part of the functionality of a base station (e.g., a network node that implements a gNB Central Unit (gNB-CU) or a network node that implements a gNB Distributed Unit (gNB-DU)) or a network node that implements part of the functionality of some other type of radio access node.

[0022] Core Network Node: As used herein, a “core network node” is any type of node in a core network or any node that implements a core network function. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a Packet Data Network Gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), or the like. Some other examples of a core network node include a node implementing a Access and Mobility Management Function (AMF), a User Plane Function (UPF), a Session Management Function (SMF), an Authentication Server Function (AUSF), a Network Slice Selection Function (NSSF), a Network Exposure Function (NEF), a Network Function (NF) Repository Function (NRF), a Policy Control Function (PCF), a Unified Data Management (UDM), or the like.

[0023] Communication Device: As used herein, a “communication device” is any type of device that has access to an access network. Some examples of a communication device include, but are not limited to: mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or Personal Computer (PC). The communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless or wireline connection.

[0024] Wireless Communication Device: One type of communication device is a wireless communication device, which may be any type of wireless device that has access to (i.e., is served by) a wireless network (e.g., a cellular network). Some examples of a wireless communication device include, but are not limited to: a User Equipment device (UE) in a 3GPP network, a Machine Type Communication (MTC) device, and an Internet of Things (loT) device. Such wireless communication devices may be, or may be integrated into, a mobile phone, smart phone, sensor device, meter, vehicle, household appliance, medical appliance, media player, camera, or any type of consumer electronic, for instance, but not limited to, a television, radio, lighting arrangement, tablet computer, laptop, or PC. The wireless communication device may be a portable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data via a wireless connection.

[0025] Network Node: As used herein, a “network node” is any node that is either part of the RAN or the core network of a cellular communications network/system.

[0026] Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system.

[0027] Note that, in the description herein, reference may be made to the term “cell”; however, particularly with respect to 5G NR concepts, beams may be used instead of cells and, as such, it is important to note that the concepts described herein are equally applicable to both cells and beams.

[0028] The solution(s) described herein are described within the context of a 3GPP-based LTE network, i.e. an EPS including E-UTRAN and EPC. However, the problems and solutions described herein are equally applicable to wireless access networks and user-equipment (UE) implementing other access technologies and standards (e.g. a 5G system including 5G core and 5G radio access). LTE is used as an example technology where the invention is suitable and using LTE in the description therefore is particularly useful for understanding the problem and solutions solving the problem. Furthermore, this invention focuses in the IOPS mode of operation, however, the problems and solutions described herein are also equally applicable to other scenarios, e.g. for the case of implementing a private network, a.k.a. non-public networks (NPN), with a local EPC or 5GC to provide application services to authorized users within the private network coverage area.

[0029] Throughout this description, it is assumed that the public safety users, also referred to herein as MC service UEs or MC users or just UEs or users, have been provided with the configuration needed to support MC services. Such a configuration, to be referred to herein as the MC service user configuration profile, is assumed to be stored at the UEs (e.g., stored by MC service clients operating on the UEs). For each UE, the MC service user configuration profile may comprise information (e.g., static data) needed for the configuration of the MC service (e.g., MCPTT service) that is supported by the UE in question. For each UE, the MC service user configuration profile may contain information about at least one of: the current UE configuration, MC service user profile configuration, group configuration (e.g., group ID), and service configuration data or similar which is stored at the UE for off-network operation (e.g., see the specific parameters described in 3GPP TS 23.280 Annex A and 3GPP TS 23.379 Annex A for the MC services and MCPTT service UE/off-network, respectively). The MC service user configuration profile can be provisioned by either offline procedures or after the UEs have been authenticated and registered with the central MC system.

[0030] The user configuration profile can also include specific configuration to be utilized in the IOPS mode of operation. It can include specific IOPS group configuration, e.g. IOPS group IP multicast addresses associated to IOPS MC service groups that a user can belong to.

[0031] In the case there is a link failure between the radio access network (eNBs) and the macro core network (EPC), it is assumed that the IOPS mode of operation is initiated, i.e. an off-network like operation, where the MC services are directly provided by the MC users, but the corresponding MC service IP packets are transmitted over the IOPS MC system. This means that the IOPS MC system only provides IP connectivity for the communication among the users. This is also defined as an IP connectivity communication in the IOPS mode of operation. For that, authorized UEs have been configured to support the IOPS mode of operation.

Figure 2

[0032] In this regard, Figure 2 illustrates one example of an IOPS MC system 200 in which embodiments of the present disclosure may be implemented. The IOPS MC system 200 includes a 3GPP IOPS system 202, which in the example embodiments described herein is an IOPS EPS. The 3GPP IOPS system 202 includes an IOPS capable base station 204, which in the example embodiments described herein is an IOPS capable eNB, and a local core 206, which in the example embodiments described herein is a local EPC. The IOPS MC system 200 also includes a MC service UE(s) 208, which includes an MC service client 210 and an IOPS connectivity client 212. The MC service client 210 and the IOPS connectivity client 212 may be implemented in software, which is executed by a processor(s) of the MC service UE 208. The IOPS MC system 200 also includes an IOPS connectivity function 214, which includes an IOPS distribution function 216. The IOPS connectivity function 214 is, in some embodiments, co-sited with the 3GPP IOPS system 212.

[0033] Embodiments related to a user emergency state in the IOPS mode of operation are described. In one embodiment, the MC service UE 208 indicates its emergency state to the IOPS MC connectivity function 214 within an IOPS discovery request. Based on this indication, the IOPS MC system 200 defines the priority for handling all transactions related to the MC service UE 208, e.g. the priority of distributing packets related to any MC communication from or to the MC service 208, subscriptions, and notifications. If the MC service UE 208 indicates that it is in an emergency state, the IOPS MC system 200 provides a highest priority to the transactions related to the MC service UE 208. Therefore, when the MC service UE 208 is intending to establish an IOPS (group or private) emergency call, the MC service UE 208 indicates that it is in an emergency state.

[0034] In one embodiment, for the case that the MC service UE 208 has been already discovered by the IOPS MC system 200 and the MC service UE 208 is not defined in an emergency state, the MC service UE 208 can update its discovery request by sending a new IOPS discovery request to the IOPS MC connectivity function. This new IOPS discovery request can include an indication that the MC service UE 208 is in the emergency state.

[0035] The emergency state of the MC service UE 208 remains unchanged until the MC service UE 208 explicitly changes it (i.e. by sending a new IOPS discovery request) or the discovery status of the MC service UE 208 changes due to not-discovered on the IOPS MC system 200.

[0036] In one embodiment, only authorized MC service UEs may be provisioned or pre-configured to indicate an emergency state in the IOPS mode of operation.

[0037] Additionally, for the case of group communications, based on the emergency state indicator, the IOPS MC system 200 can define the IOPS groups associated to the corresponding MC service UE as groups in an emergency state. Thus, while the corresponding MC service UE is defined as discovered by the IOPS MC system 200 and it is in an emergency state, the associated IOPS groups are served with a highest priority, i.e. the distribution of packets addressed to the associated IOPS groups are distributed with the highest priority by the IOPS MC system.

[0038] In a further embodiment, the MC service UE 208 may explicitly indicate within the IOPS discovery request which IOPS group(s) should be defined as in an emergency state. Hence, only packets received by the IOPS MC system 200 that are addressed to the indicated IOPS group(s) are handled with the highest priority. [0039] When the corresponding MC service UE 208 initiates a communication in the IOPS mode of operation, it can additionally or alternatively indicate in the IOPS (group or private) call setup if the call is an emergency call. Hence, the called MC user(s) are notified that the call is an emergency call and can provide the highest priority for the handling of the corresponding communication.

[0040] In an embodiment, if the MC service UE 208 has not indicated to the IOPS MC system 200 that it is in an emergency state, but the MC service UE 208 desires to establish an emergency call as soon as possible, the MC service UE 208 can initiate establishing the communication while sending a new IOPS discovery request that includes an indication of the emergency state. For that, the MC service UE 208 can assign the highest priority to the related IP packets by means of using the differentiated service field (DS field) within the IP header, as described in RFC 2474. The IOPS MC system 200 can consider distributing the received IP packets with a different priority based on the DS field.

[0041] Table 5.2-1 below shows the enhanced IOPS discovery request including the new information elements to indicate the MC user’s emergency state and optionally the IOPS group(s) that should also be defined in an emergency state in accordance one example of some embodiments of the present disclosure. Table 5.2-1 : IOPS discovery request

Figure 3

[0042] One example of a discovery procedure for the MC service UE 208 in the IOPS mode of operation is illustrated in Figure 3. Note that optional steps are represented by dashed lines/boxes. The IOPS discovery is initiated by the MC service UE 208 to support MC services based on the IP connectivity functionality. [0043] As part of the IOPS discovery procedure, the MC service UE 208 can indicate its emergency state to the IOPS MC connectivity function 214, as described above. Based on this indication, the IOPS MC connectivity function 214 can define the priority for handling transactions related to the MC service UE 208, e.g. the priority for distributing packets related to any MC communication from or to the MC service UE 208, subscriptions, and notifications. If the MC service UE 208 indicates that it is in an emergency state, the IOPS MC connectivity function 214 can provide higher access privileges, i.e. a higher priority, to the MC user's related transactions. So, when the MC service UE 208 is intending to establish an IOPS emergency (group or private) call, the MC service UE 208 indicates that it is in an emergency state.

[0044] Based on the emergency state of the MC service UE 208, the IOPS MC connectivity function 214 can define IOPS groups associated to the MC service UE 208 as also being in an emergency state. Thus, while the MC service UE 208 is defined as discovered by the IOPS MC connectivity function 214 and it is in an emergency state, the associated IOPS groups can be served with a higher priority, i.e. the distribution of packets addressed to the associated IOPS groups are distributed with a higher priority by the IOPS distribution function. Also, the MC service UE 208 may explicitly indicate within the IOPS discovery request which IOPS group(s) are to be defined as in an emergency state.

[0045] In one embodiment, the MC user's emergency state remains unchanged until the MC service UE 208 explicitly changes it (i.e. by sending a new IOPS discovery request) or the discovery status of the MC service UE 208 changes to not-discovered on the IOPS MC connectivity function 214.

[0046] Some example pre-conditions for the discovery procedure are as follows:

• the MC service UE 208 is authenticated on the IOPS MC connectivity function 214; • the MC service UE 208 has an active Packet Data Network (PDN) connection to the IOPS MC connectivity function 214 for the specific IP connectivity functionality procedure; and

• the IOPS MC connectivity function 214 has indicated to the IOPS connectivity client 212 the support of the IP connectivity functionality.

[0047] The steps of the discovery procedure of Figure 3 are as follows:

• Step 300: The MC service UE 208 sends an IOPS discovery request to the IOPS MC connectivity function 214. The request includes providing connectivity information for the support of MC services based on the IP connectivity functionality. As described above, the IOPS discovery request includes an indication of an emergency state of the MC service UE 208. As also described above, in some embodiments, the IOPS discovery request may also include information that indicates one or more IOPS groups that are in an emergency state.

• Step 302: The IOPS MC connectivity function 214 performs one or more actions based on or using the information included in the IOPS discovery request, including the emergency indication. For example, the IOPS MC connectivity function 214 stores the information received from the MC service UE 208 in the IOPS discovery request and registers the connectivity status of the MC service UE 208 as discovered. In addition, based on the emergency state indication included in the IOPS discovery request and, optionally, the information that indicates one or more IOPS groups as being in an emergency state also included in the IOPS discovery request, the IOPS MC connectivity function 214 provides higher access privileges, i.e. a higher priority, to the MC user's related transactions, as described above.

• Step 304: The IOPS MC connectivity function 214 provides a response to the IOPS connectivity client 210 indicating the success or failure of the discovery of the requesting MC service UE 208.

• Step 306 (Optional): Note that the MC service UE 208sends a new IOPS discovery request to update or modify information elements.

[0048] Note that, in one embodiment, the IOPS MC connectivity function 214 sends a new IOPS discovery response to the IOPS connectivity client 210 for the case that the periodic IOPS discovery request has not been received yet or when the IOPS discovery request periodicity needs to be changed. The IOPS MC connectivity function 214 can verify the availability and IP connectivity information of the discovered MC service UE 208within the IOPS MC system 200 based on the reception of periodic IOPS discovery requests. Figure 4

[0049] Figure 4 is a schematic block diagram of a network 400 according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The network 400 may be, for example, the IOPS capable base station 204 or a network node that implements the functionality of the IOPS MC connectivity function 214 described herein. Note that, in one particular embodiment, the IOPS MC connectivity function 214 is implemented at the IOPS capable base station 204. However, in another embodiment, the IOPS MC connectivity function 214 is implemented on a separate network node, e.g., that is connected to and preferably co-sited with the IOPS capable base station 204. All or part of the functionality of the IOPS connectivity function 214 described above (e.g., with respect to Figure 3) may be implemented in the network node 400, in some embodiments.

[0050] As illustrated, the network node 400 includes a control system 402 that includes one or more processors 404 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory 406, and a network interface 408. The one or more processors 404 are also referred to herein as processing circuitry. In addition, if the network node 400 is a radio access node, the network node 400 also includes one or more radio units 410 that each includes one or more transmitters 412 and one or more receivers 414 coupled to one or more antennas 416. The radio units 410 may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s) 410 is external to the control system 402 and connected to the control system 402 via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) 410 and potentially the antenna(s) 416 are integrated together with the control system 402. The one or more processors 404 operate to provide one or more functions of a radio access node 400 as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory 406 and executed by the one or more processors 404.

Figure 5

[0051] Figure 5 is a schematic block diagram that illustrates a virtualized embodiment of the network node 400 according to some embodiments of the present disclosure. Again, optional features are represented by dashed boxes. As used herein, a “virtualized” network node is an implementation of the network node 400 in which at least a portion of the functionality of the network node 400 is implemented as a virtual component(s) (e.g., via a virtual machine(s) executing on a physical processing node(s) in a network(s)). As illustrated, in this example, the network node 400 may optionally include the control system 402 and/or the one or more radio units 410, as described above. The network node 400 includes one or more processing nodes 500 coupled to or included as part of a network(s) 502. If present, the control system 402 or the radio unit(s) are connected to the processing node(s) 500 via the network 502. Each processing node 500 includes one or more processors 504 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 506, and a network interface 508.

[0052] In this example, functions 510 of the network node 400 described herein (e.g., all or part of the functionality of the IOPS connectivity function 214 described above) are implemented at the one or more processing nodes 500 or distributed across the one or more processing nodes 500 and the control system 402 and/or the radio unit(s) 410 in any desired manner. In some particular embodiments, some or all of the functions 510 of the network node 400 described herein are implemented as virtual components executed by one or more virtual machines implemented in a virtual environment(s) hosted by the processing node(s) 500. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 500 and the control system 402 is used in order to carry out at least some of the desired functions 510. Notably, in some embodiments, the control system 402 may not be included, in which case the radio unit(s) 410 communicate directly with the processing node(s) 500 via an appropriate network interface(s). [0053] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the network node 400 or a node (e.g., a processing node 500) implementing one or more of the functions 510 of the network node 400 in a virtual environment according to any of the embodiments described herein is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

Figure 6

[0054] Figure 6 is a schematic block diagram of the network node 400 according to some other embodiments of the present disclosure. The network node 400 includes one or more modules 600, each of which is implemented in software. The module(s) 600 provide the functionality of the network node 400 described herein (e.g., all or part of the functionality of the IOPS connectivity function 214 described above). This discussion is equally applicable to the processing node 500 of Figure 5 where the modules 600 may be implemented at one of the processing nodes 500 or distributed across multiple processing nodes 500 and/or distributed across the processing node(s) 500 and the control system 402. Figure 7

[0055] Figure 7 is a schematic block diagram of a wireless communication device 700 according to some embodiments of the present disclosure. The wireless communication device 700 is one example of the MC service UE 208. As illustrated, the wireless communication device 700 includes one or more processors 702 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 704, and one or more transceivers 706 each including one or more transmitters 708 and one or more receivers 710 coupled to one or more antennas 712. The transceiver(s) 706 includes radio-front end circuitry connected to the antenna(s) 712 that is configured to condition signals communicated between the antenna(s) 712 and the processor(s) 702, as will be appreciated by on of ordinary skill in the art. The processors 702 are also referred to herein as processing circuitry. The transceivers 706 are also referred to herein as radio circuitry. In some embodiments, the functionality of the wireless communication device 700 described above (e.g., all or part of the functionality the MC service UE described above) may be fully or partially implemented in software that is, e.g., stored in the memory 704 and executed by the processor(s) 702. Note that the wireless communication device 700 may include additional components not illustrated in Figure 7 such as, e.g., one or more user interface components (e.g., an input/output interface including a display, buttons, a touch screen, a microphone, a speaker(s), and/or the like and/or any other components for allowing input of information into the wireless communication device 700 and/or allowing output of information from the wireless communication device 700), a power supply (e.g., a battery and associated power circuitry), etc.

[0056] In some embodiments, a computer program including instructions which, when executed by at least one processor, causes the at least one processor to carry out the functionality of the wireless communication device 700 according to any of the embodiments described herein (e.g., all or part of the functionality the MC service UE described above) is provided. In some embodiments, a carrier comprising the aforementioned computer program product is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as memory).

Figure 8

[0057] Figure 8 is a schematic block diagram of the wireless communication device 700 according to some other embodiments of the present disclosure. The wireless communication device 700 includes one or more modules 800, each of which is implemented in software. The module(s) 800 provide the functionality of the wireless communication device 700 described herein (e.g., all or part of the functionality the MC service UE described above). [0058] Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

[0059] While processes in the figures may show a particular order of operations performed by certain embodiments of the present disclosure, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, etc.).

[0060]

Some Embodiments

1. A method performed by a wireless communication device (208) indicating an emergency state while operating in an isolated radio access network mode of operation, the method comprising: sending (300), to a connectivity function (214) of an isolated radio access network system, a discovery request that comprises an indication that the wireless communication device (208) is in an emergency state; and receiving (304) a discovery response from the connectivity function (214).

2 The method of embodiment 1 wherein the indication indicates that the wireless communication device

(208) is in the emergency state for a private service (e.g. a private call) or a group service (e.g., a group call). 3. The method of embodiment 1 or 2 wherein the discovery request further comprises information that indicates one or more service groups for which the wireless communication device (208) is in the emergency state.

4. The method of any one of embodiments 1 to 3 further comprising sending (306) a new discovery request to the connectivity function (214) that comprises an indication that the wireless communication device (208) is either in the emergency state or not in the emergency state.

5. The method of any one of embodiments 1 to 4 further comprising indicating, in a call setup message, whether the wireless communication device (208) is in the emergency state.

6. The method of any one of embodiments 1 to 4 wherein sending (300) the discovery request comprises sending (300) the discovery request while establishing an emergency call.

7. The method of any one of embodiments 1 to 6 wherein the isolated radio access network mode of operation is an IOPS mode of operation, and the isolated radio access network system is an IOPS system.

8. The method of any one of embodiments 1 to 6 wherein the isolated radio access network mode of operation is an IOPS mode of operation for MC services, and the isolated radio access network system is an IOPS MC system.

9. A wireless communication device (208) for indicating an emergency state while operating in an isolated radio access network mode of operation, the wireless communication device (208) adapted to: send (300), to a connectivity function (214) of an isolated radio access network system, a discovery request that comprises an indication that the wireless communication device (208) is in an emergency state; and receive (304) a discovery response from the connectivity function (214).

10. The wireless communication device (208) of embodiment 9 wherein the wireless communication device (208) is further adapted to perform the method of any one of embodiments 2 to 8. 11. The wireless communication device (208) of embodiment 9 or 10 wherein the wireless communication device (208) comprises: one or more transmitters (708); one or more receivers (710); and processing circuitry (702) associated with the one or more transmitters (708) and the one or more receivers (710), the processing circuitry (702) configured to cause the wireless communication device (208) to: send (300), to a connectivity function (214) of an isolated radio access network system, a discovery request that comprises an indication that the wireless communication device (208) is in an emergency state; and receive (304) a discovery response from the connectivity function (214).

12. A method performed by a connectivity function (214) of an isolated radio access network system (200), the method comprising: receiving (300), from a wireless communication device (208), a discovery request that comprises an indication that the wireless communication device (208) is in an emergency state; performing (302) one or more actions based on information comprises in the discovery request, including the indication; and sending (304) a discovery response to the wireless communication device (208).

13. The method of embodiment 12 wherein the indication indicates that the wireless communication device (208) is in the emergency state for a private service (e.g. a private call) or a group service (e.g., a group call).

14. The method of embodiment 13 wherein the one or more actions comprise defining a priority for handling transactions related to the wireless commination device (208) in the isolated radio access network system (e.g., defining the priority of distributing packets related to any communication (e.g., MC communication) from or to the wireless communication device (208), subscriptions, and/or notifications).

15. The method of embodiment 13 or 14 wherein the one or more actions comprise defining one or more service groups (e.g., one or more IOPS groups) associated to the wireless communication device (208) as groups in an emergency state. 16. The method of any one of embodiments 12 to 14 wherein the discovery request further comprises information that indicates one or more service groups for which the wireless communication device (208) is in the emergency state.

17. The method of any one of embodiments 12 to 15 further comprising receiving (306) a new discovery request from the wireless communication device (208) that comprises an indication that the wireless communication device (208) is either in the emergency state or not in the emergency state.

18. The method of any one of embodiments 12 to 17 wherein the discovery request is received while the wireless communication device (208) is establishing an emergency call.

19. The method of any one of embodiments 12 to 18 wherein the isolated radio access network system is an I OPS system.

20. The method of any one of embodiments 12 to 18 wherein the isolated radio access network system is an I OPS MC system.

21. A network node (400) implementing a connectivity function (214) for an isolated radio access network system (200), the network node (400) adapted to: receive (300), from a wireless communication device (208), a discovery request that comprises an indication that the wireless communication device (208) is in an emergency state; perform (302) one or more actions based on the information comprises in the discovery request; and send (304) a discovery response to the wireless communication device (208).

22. The network node (400) of embodiment 21 wherein the network node (400) is further adapted to perform the method of any one of embodiments 13 to 20.

23. The network node (400) of embodiment 21 or 22 wherein the network node (400) comprises processing circuitry (404; 504) configured to cause the network node (400) to: receive (300) the discovery request that comprises the indication that the wireless communication device (208) is in the emergency state from the wireless communication device (208); perform (302) the one or more actions based on information comprised in the discovery request, including the indication; and send (304) the discovery response to the wireless communication device (208).

Abbreviations

At least some of the following abbreviations may be used in this disclosure. If there is an inconsistency between abbreviations, preference should be given to how it is used above. If listed multiple times below, the first listing should be preferred over any subsequent listing(s).

3GPP Third Generation Partnership Project

5G Fifth Generation

5GC Fifth Generation Core

5GS Fifth Generation System

ASIC Application Specific Integrated Circuit

CPU Central Processing Unit

DSP Digital Signal Processor eNB Enhanced or Evolved Node B

EPC Evolved Packet Core

EPS Evolved Packet System

E-UTRA Evolved Universal Terrestrial Radio Access

E-UTRAN Evolved Universal Terrestrial Radio Access Network

FPGA Field Programmable Gate Array

GC Group Communication gNB New Radio Base Station

FISS Flome Subscriber Server

IOPS Isolated Evolved Universal Terrestrial Radio Access Network Operations for

Public Safety

IP Internet Protocol

LTE Long Term Evolution

MC Mission Critical

MME Mobility Management Entity

NR New Radio

P-GW Packet Data Network Gateway • ProSe Proximity Services

• PTT Push to Talk

• QoS Quality of Service

• RAM Random Access Memory · RAN Radio Access Network

• ROM Read Only Memory

• RRH Remote Radio Head

• UE User Equipment

Appendix A

3GPP TSG-SA WG6 Meeting #36-BIS-e S6-200xxx

E-meeting, 31 ^st March - 8 ^th April 2020 (revision of S6-20xxxx)

Source: Ericsson

Title: Pseudo-CR on Emergency group calls in IOPS

Spec: 3GPP TS 23.180 v0.3.0

Agenda item: 7.2 Document for: Approval Contact: Camilo Solano (camilo.solano@ericsson.com)

1. Introduction

As described in section 5.2, MCPTT emergency group calls shall be supported in the IOPS mode of operation. For that, based on the IP connectivity functionality and as described in S6-200xxx, an MC user can indicate within the IOPS discovery request its emergency state to the IOPS MC connectivity function. Based on this indication, the IOPS MC system defines the priority for handling all the MC user’s related transactions, e.g. the priority for distributing packets related to any MC communication from or to the corresponding MC user, subscriptions and notifications. Nevertheless, an MC user shall also indicate during an IOPS group call if it is an emergency call. Hence, the called group’s MC users can be notified that the call is an emergency call and can provide a higher priority for the handling of the corresponding communication. Besides, an IOPS group call in-progress can be upgraded to an emergency call.

2. Reason for Change

For the support of MC services in IOPS based on the IP connectivity functionality, the IOPS group call procedure is updated to support IOPS emergency group calls.

3. Conclusions

<Conclusion part (optional)>

4. Proposal

It is proposed to approve the following changes to 3GPP TS 23.180 v0.3.0.

10.5.1.2.1 IOPS group call announcement

Table 10.5.1.2.1-1 describes the information flow for the IOPS group call announcement from one MCPTT client to other MCPTT clients. The packet(s) carrying the IOPS group call announcement are transmitted from the originating MCPTT client to the IOPS MC connectivity function for distribution to the target MCPTT clients. Table 10.5.1.2.1-1: IOPS group call announcement

10.5.1.2.x IOPS emergency group call upgrade

Table 10.5.1.2.X-1 describes the information flow for the IOPS emergency group call upgrade from one MCPTT client to other MCPTT clients. The packet(s) carrying the IOPS emergency group call upgrade are transmitted from the originating MCPTT client to the IOPS MC connectivity function for distribution to the target MCPTT clients.

Table 10.5.1.2.X-1 : IOPS emergency group call upgrade

10.5.1.2. y IOPS emergency group call state cancel

Table 10.5.1.2.y-l describes the information flow for the IOPS emergency group call state cancel from one MCPTT client to other MCPTT clients. The packet(s) carrying the IOPS emergency group call state cancel are transmitted from the originating MCPTT client to the IOPS MC connectivity function for distribution to the target MCPTT clients.

Table 10.5.1.2.y-1: IOPS emergency group call state cancel 10.5.1.x IOPS emergency group call

The IOPS emergency group call is a special case of the IOPS group call setup procedure described in clause 10.5.1.3. The following are further considerations required for the aforementioned clause to support an IOPS emergency group call:

- The MCPTT client initiating an IOPS emergency group call may have previously been provisioned with a specific IOPS MCPTT group(s) designated as the IOPS MCPTT emergency group(s). The MCPTT client initiates IOPS emergency group calls on this IOPS group(s). Alternatively, the MCPTT client could have been provisioned for an emergency behaviour on the selected IOPS MCPTT group.

- As a pre-condition, the MCPTT client initiating an IOPS emergency group call may have indicated within the IOPS discovery request that it is in an emergency state. Additionality, the MCPTT client may have indicated the specific IOPS MCPTT group(s) designated as the IOPS MCPTT emergency group(s).

- The IOPS group call announcement contains an indication that the IOPS group call is an IOPS emergency group call. Hence, group call participants are notified that the group call is an emergency call and therefore, can provide a higher priority for the handling of the corresponding communication.

- The originating MCPTT client of an IOPS group call in-progress can upgrade the call to an IOPS emergency group call by including the emergency indicator within the periodic IOPS group call announcement.

- An IOPS group call in-progress may be upgraded by another participating MCPTT client by sending an IOPS emergency group call upgrade to the IOPS group.

- The originating MCPTT user of an IOPS emergency group call in-progress, or the MCPTT user who upgraded an IOPS group call to an emergency group call can cancel the emergency state of the call by sending an IOPS emergency group call state cancel to the IOPS group.

- An IOPS emergency group call becomes cancelled when the call is released or the emergency call state is cancelled.

NOTE: Only the MCPTT client initiating an IOPS emergency group call is required to indicate within an IOPS discovery request its emergency state to the IOPS MC connectivity function. The group call participants are not lurther required to indicate an emergency state.

Appendix B

3GPP TSG-SA WG6 Meeting #36-BIS-e S6-200xxx

E-meeting, 31 ^st March - 8 ^th April 2020 (revision of S6-20xxxx)

Source: Ericsson

Title: Pseudo-CR on Emergency private calls in IOPS

Spec: 3GPP TS 23.180 v0.3.0

Agenda item: 7.2 Document for: Approval Contact: Camilo Solano (camilo.solano@ericsson.com)

1. Introduction

As described in section 5.2, MCPTT emergency private calls shall be supported in the IOPS mode of operation. For that, based on the IP connectivity functionality and as described in S6-200xxx, an MC user can indicate within the IOPS discovery request its emergency state to the IOPS MC connectivity function. Based on this indication, the IOPS MC system defines the priority for handling all the MC user’s related transactions, e.g. the priority for distributing packets related to any MC communication from or to the corresponding MC user, subscriptions and notifications. Nevertheless, an MC user shall also indicate during an IOPS private call if it is an emergency call. Hence, the called MC user can be notified that the call is an emergency call and can provide a higher priority for the handling of the corresponding communication. Besides, an IOPS private call in-progress can be upgraded to an emergency call.

2. Reason for Change

For the support of MC services in IOPS based on the IP connectivity functionality, the IOPS private call procedure is updated to support IOPS emergency private calls.

3. Conclusions

<Conclusion part (optional)>

4. Proposal

It is proposed to approve the following changes to 3GPP TS 23.180 v0.3.0.

10.5.2.2.1 IOPS call setup request

Table 10.5.2.2.1-1 describes the information flow for the IOPS call setup request from one MCPTT client to another MCPTT client. The packet(s) carrying the IOPS call setup request are transmitted from the calling MCPTT client to the IOPS MC connectivity function for distribution to the called MCPTT client. Table 10.5.2.2.1-1: IOPS call setup request

10.5.2.2.x IOPS emergency private call upgrade

Table 10.5.2.2.X-1 describes the information flow for the IOPS emergency private call upgrade from one MCPTT client to another MCPTT client. The packet(s) carrying the IOPS emergency private call upgrade are transmitted from the originating MCPTT client to the IOPS MC connectivity function for distribution to the target MCPTT client.

Table 10.5.2.2.X-1 : IOPS emergency private call upgrade

10.5.2.2. y IOPS emergency private call state cancel

Table 10.5.2.2.y-l describes the information flow for the IOPS emergency private call state cancel from one MCPTT client to another MCPTT client. The packet(s) carrying the IOPS emergency private call state cancel are transmitted from the originating MCPTT client to the IOPS MC connectivity function for distribution to the target MCPTT client.

Table 10.5.2.2.y-1: IOPS emergency private call state cancel

10.5.2.x IOPS emergency private call

The IOPS emergency private call is a special case of the IOPS private call setup procedures described in clause 10.5.2.3. The following are further considerations required for the aforementioned clause to support an IOPS emergency group call:

- As a pre-condition, the MCPTT client initiating an IOPS emergency group call may have indicated within the IOPS discovery request that it is in an emergency state.

- The IOPS call setup request contains an indication that the IOPS private call is an IOPS emergency call. Hence, the called MCPTT user is notified that the call is an emergency call and therefore, can provide a higher priority for the handling of the corresponding communication. - Either call participant of an IOPS private call in-progress can upgrade the call to an IOPS emergency private call by sending an IOPS emergency private call upgrade.

- The originating MCPTT user of an IOPS emergency private call in-progress, or the MCPTT user who upgraded an IOPS private call to an emergency private call can cancel the emergency state of the call by sending an IOPS emergency private call state cancel.

- An IOPS emergency private call becomes cancelled when the call is released or the emergency call state is cancelled.

NOTE: Only the MCPTT client initiating an IOPS emergency private call is required to indicate within an IOPS discovery request its emergency state to the IOPS MC connectivity function. The other participant is not further required to indicate an emergency state.

Appendix C

3GPP TSG-SA WG6 Meeting #36-BIS-e S6-200xxx

E-meeting, 31 ^st March - 8 ^th April 2020 (revision of S6-20xxxx)

Source: Ericsson

Title: Pseudo-CR on MC user’s emergency state in IOPS

Spec: 3GPP TS 23.180 v0.3.0

Agenda item: 7.2 Document for: Approval Contact: Camilo Solano (camilo.solano@ericsson.com)

1. Introduction

As described in section 5.2, MCPTT emergency group and private calls shall be supported in the IOPS mode of operation. For that, based on the IP connectivity functionality, an MC user can indicate within the IOPS discovery request its emergency state to the IOPS MC connectivity function. Based on this indication, the IOPS MC system defines the priority for handling all the MC user’s related transactions, e.g. the priority for distributing packets related to any MC communication from or to the corresponding MC user, subscriptions and notifications. If an MC user indicates that it is in an emergency state, the IOPS MC connectivity function provides elevate access privileges, i.e. a higher priority, to the MC user’s related transactions. So, when an MC user is intending to establish an IOPS (group or private) emergency call, the MC user indicates that it is in an emergency state.

Optionally, for the case of group communications, the IOPS MC connectivity function based on the MC user’s emergency state can define the IOPS groups associated to the corresponding MC user as groups in an emergency state. Thus, while the corresponding MC user is defined as discovered by the IOPS MC system and it is in an emergency state, the associated IOPS groups are served with a higher priority, i.e. the distribution of packets addressed to the associated IOPS groups are distributed with a higher priority by the IOPS MC connectivity function. Also, the MC user may explicitly indicate within the IOPS discovery request which IOPS group(s) should be defined as in an emergency state.

This contribution updates the IOPS discovery procedure to include the user’s emergency state.

2. Reason for Change

For the support of MC services in IOPS based on the IP connectivity functionality, an MC user can indicate within the IOPS discovery procedure its emergency state. Thus, the IOPS MC connectivity function can provide elevate access privileges, i.e. a higher priority, to the MC user’s related transactions.

3. Conclusions

<Conclusion part (optional)>

4. Proposal

It is proposed to approve the following changes to 3GPP TS 23.180 v0.3.0. 10.2.2.3 IOPS discovery request

Table 10.2.2.3-1 describes the information flow for the IOPS discovery request from the IOPS connectivity client to the IOPS MC connectivity function.

Table 10.2.2.3-1 : IOPS discovery request

10.2.3 Procedure

After an MC service user is authenticated on the IOPS MC connectivity function, the IOPS discovery procedure is initiated by the MC users requesting support of the IP connectivity functionality to the IOPS MC connectivity function.

If the IOPS MC connectivity function indicates the support of the IP connectivity functionality, the MC service users can send an IOPS discovery request.

The procedure for requesting support of the IP connectivity functionality by the IOPS connectivity client to the IOPS MC connectivity function is described in figure 10.2.3-1.

NOTE 1 : The procedure for requesting support of the IP connectivity functionality is only required when the IOPS connectivity client does not contain information about the support of this functionality by the serving IOPS MC connectivity function.

Pre-conditions:

- The MC service user is authenticated on the IOPS MC connectivity function.

- The MC service user has an active PDN connection to the IOPS MC connectivity function for the specific IP connectivity functionality procedure

The IOPS connectivity client does not contain information about the support of the IP connectivity functionality by the serving IOPS MC connectivity function

Figure 10.2.3-1 IP connectivity functionality request in the IOPS mode of operation

1. The IOPS connectivity client requests to the IOPS MC connectivity iunction the support of the IP connectivity functionality.

2. The IOPS MC connectivity function indicates to the IOPS connectivity client if the IP connectivity functionality is supported or not for the MC user.

The procedure for the discovery of MC users in the IOPS mode of operation is described in figure 10.2.3-2. The IOPS discovery is initiated by the MC users to support MC services based on the IP connectivity functionality.

As part of the IOPS discovery procedure, an MC user can indicate its emergency state to the IOPS MC connectivity function. Based on this indication, the IOPS MC connectivity function can define the priority for handling the MC user's related transactions, e.g. the priority for distributing packets related to any MC communication from or to the corresponding MC user, subscriptions and notifications. If an MC user indicates that it is in an emergency state, the IOPS MC connectivity function can provide higher access privileges, i.e. a higher priority, to the MC user's related transactions. So, when an MC user is intending to establish an IOPS emergency (group or private) call, the MC user indicates that it is in an emergency state.

The IOPS MC connectivity iunction based on the MC user's emergency state can define in an emergency state the IOPS groups associated to the corresponding MC user. Thus, while the corresponding MC user is defined as discovered by the IOPS MC connectivity function and it is in an emergency state, the associated IOPS groups can be served with a higher priority, i.e. the distribution of packets addressed to the associated IOPS groups are distributed with a higher priority by the IOPS distribution function. Also, the MC user may explicitly indicate within the IOPS discovery request which IOPS group(s) shall be defined as in an emergency state.

The MC user's emergency state remains unchanged until the MC user explicitly changes it (i.e. by sending a new IOPS discovery request) or the MC user's discovery status changes to no-discovered on the IOPS MC connectivity function.

Pre-conditions:

- The MC service user is authenticated on the IOPS MC connectivity function.

- The MC service user has an active PDN connection to the IOPS MC connectivity function for the specific IP connectivity functionality procedure

The IOPS MC connectivity function has indicated to the IOPS connectivity client the support of the IP connectivity functionality.

Figure 10.2.3-2 User discovery in the IOPS mode of operation

1. The MC user sends an IOPS discovery request to the IOPS MC connectivity function. The request includes providing connectivity information for the support of MC services based on the IP connectivity functionality.

2. The IOPS MC connectivity function stores the information received from the MC user and registers the user's connectivity status as discovered.

3. The IOPS MC connectivity function provides a response to the IOPS connectivity client indicating the success or failure of the discovery of the requesting MC user.

NOTE 2: The MC user shall send a new IOPS discovery request to update or modify information elements.

NOTE 3 : The IOPS MC connectivity function shall send a new IOPS discovery response to the IOPS connectivity client for the case that the periodic IOPS discovery request has not been received yet or when the IOPS discovery request periodicity needs to be changed. The IOPS MC connectivity function can verily the availability and IP connectivity information of the discovered MC user within the IOPS MC system based on the reception of periodic IOPS discovery requests.