EP3949679A1

EP3949679A1 - Iops user availability verification

Info

Publication number: EP3949679A1
Application number: EP20842694.0A
Authority: EP
Inventors: John Camilo SOLANO ARENAS
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2020-01-07
Filing date: 2020-12-16
Publication date: 2022-02-09
Also published as: WO2021139981A1

Abstract

Disclosed herein is a method performed by an IOPS connectivity client (316) of a wireless communication device (312). The method comprising: sending (400) a request to an IOPS connectivity function (300) of an IOPS system, the request being a request for an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality; and receiving (402) a response from the IOPS connectivity function (300), the response comprising an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality.

Description

IOPS USER A VAI LABILITY VERIFICA TION

1 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 communications service requires 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 that the same information is delivered to multiple users. One type of Group Communication is Push to Talk (PTT) service. A Group Communication 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 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 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 like 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 (UE) providing MC service communications support. The MC service UE primarily obtains access to a MC service via Evolved Universal Mobile Telecommunications System (UMTS) 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 to 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 service 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 E-UTRAN radio base station(s) (enhanced or evolved Node B(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, 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.

[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. During 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 users, but the corresponding MC service IP packets are transmitted over the IOPS EPS to an IOPS MC system. The IOPS MC system, which is co-located with the IOPS EPS, distributes those IP packets to the targeted user(s) over the IOPS EPS. [0010] The support of MC services in the IOPS mode of operation is being specified in 3GPP TS 23.180 (currently in TS 23.180 v0.2.0). As described here, the IOPS MC system is represented by a functional model that includes an IOPS MC connectivity function and an IOPS distribution function. On the other hand, the UE includes an MC service client and an IOPS connectivity client to support MC services in the IOPS mode of operation.

[0011] Figure 1 depicts a general IOPS system.

[0012] 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.

[0013] Considering that the IOPS mode of operation is an off-network like operation, for the case of a one to one communication, e.g. a private call between two users, the IP packets received by the IOPS distribution function have, as their final destination IP address, the unicast IP address of the targeted user. For the case of a group communication, e.g. a group call, the IP packets received by the IOPS distribution function have, as their final destination IP address, the multicast IP address of the targeted group.

[0014] 3GPP TS 23.180 v0.2.0 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. An MC user includes within the IOPS discovery request 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.

2 SUMMARY

[0015] 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 can comprise small coverage areas, e.g. for the case of only one eNB or very few eNBs operating in IOPS and connected to the same local EPC. This can lead to a problem where discovered MC UEs can suddenly move out from the IOPS system coverage and the IOPS MC connectivity function cannot be aware of it. Likewise, other MC UEs that have received a notification about the availability of an MC UE within the IOPS system are not aware of that MC UE has moved out from the coverage of the IOPS system. Also, every time an MC UE moves into an IOPS system coverage, the IP connectivity information may change, e.g. the UE’s IP address assigned by the IOPS EPC. Therefore, mechanisms are required to define how the IOPS MC connectivity function can verify the availability and IP connectivity information of MC UEs which have already been registered as discovered. [0016] Certain aspects of the present disclosure and their embodiments may provide solutions to the aforementioned or other challenges. Systems and methods are disclosed herein that provide mechanisms to be implemented in the IOPS mode of operation to verify the availability of discovered MC UEs on the IOPS MC system. This improves the performance of the IOPS MC system since the notification to others MC UEs can be kept updated and valid.

[0017] In some embodiments, systems and methods are disclosed herein for verifying the availability and IP connectivity information of discovered MC UEs on an IOPS MC system.

[0018] There are, proposed herein, various embodiments which address one or more of the issues disclosed herein.

[0019] One embodiment is directed to a method performed by an IOPS connectivity client of a wireless communication device. The method comprises: sending a request to an IOPS connectivity function of an IOPS system, the request being a request for an indication of whether the IOPS connectivity function supports IP connectivity functionality; and receiving a response from the IOPS connectivity function, the response comprising an indication of whether the IOPS connectivity function supports IP connectivity functionality. [0020] Another embodiment is directed to method performed by an IOPS connectivity client of a wireless communication device. The method comprises: sending an IOPS discovery request to an IOPS connectivity function of an IOPS system; and receiving an IOPS discovery response from the IOPS connectivity function, the IOPS discovery response comprising information that indicates that the IOPS connectivity client is to periodically transmit IOPS discovery requests.

[0021] Another embodiment is directed to a wireless communication device adapted to perform the method of any of the above methods.

[0022] Another embodiment is directed to a method performed by a network node that implements an IOPS connectivity function of an IOPS system, the method comprises: receiving a request from an IOPS connectivity client of a wireless communication device, the request being a request for an indication of whether the IOPS connectivity function supports IP connectivity functionality; and sending a response to the IOPS connectivity client, the response comprising an indication of whether the IOPS connectivity function supports IP connectivity functionality. [0023] Another embodiment is directed to a method performed by a network node that implements an IOPS connectivity function of an IOPS system, the method comprising: receiving an IOPS discovery request from an IOPS connectivity client of a wireless communication device; and sending an IOPS discovery response to the IOPS connectivity client, the IOPS discovery response comprising information that indicates that the IOPS connectivity client is to periodically transmit IOPS discovery requests.

[0024] Another embodiment is directed to a network node (700) that implements an IOPS connectivity function (300) of an IOPS system, the network node (700) adapted to perform any of the above methods performed by a network node.

[0025] Certain embodiments may provide one or more of the following technical advantage(s). Certain embodiments provide the advantage of defining new mechanisms that can be used by the IOPS MC connectivity function to verify the availability of discovered MC UEs on the IOPS MC system. Certain embodiments provide the advantage that discovered MC UEs can be properly notified about the availability of other discovered MC UEs within the IOPS system.

3 BRIEF DESCRIPTION OF THE DRAWINGS

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

Figure 1 depicts a general IOPS system;

Figure 2 illustrates one example of a cellular communications system 200 in which embodiments of the present disclosure may be implemented;

Figure 3 illustrates one example architecture of an IOPS system for embodiments of the present disclosure;

Figure 4 illustrates a procedure for requesting support of IP connectivity functionality by an IOPS connectivity client of a MC service UE to an IOPS MC connectivity function in in accordance with one example embodiment of the present disclosure;

Figure 5 illustrates a procedure for discovery of MC service UEs in an IOPS mode of operation in accordance with an embodiment of the present disclosure;

Figure 6 illustrates the operation of an IOPS connectivity client of a particular MC service UE and an IOPS connectivity function in accordance with at least some aspects of the embodiments of the present disclosure;

Figure 7 is a schematic block diagram of a radio access node according to some embodiments of the present disclosure; Figure 8 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node according to some embodiments of the present disclosure;

Figure 9 is a schematic block diagram of the radio access node 700 according to some other embodiments of the present disclosure;

Figure 10 is a schematic block diagram of a wireless communication device according to some embodiments of the present disclosure;

Figure 11 is a schematic block diagram of the wireless communication device 1000 according to some other embodiments of the present disclosure.

4 DETAILED DESCRIPTION

[0026] 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. Additional information may also be found in the document(s) provided in the Appendix.

[0027] Radio Node: As used herein, a “radio node” is either a radio access node or a wireless communication device.

[0028] 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 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.

[0029] 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 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.

[0030] 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.

[0031] 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.

[0032] Network Node: As used herein, a “network node” is any node that is either part of the radio access network or the core network of a cellular communications network/system.

[0033] 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. Flowever, the concepts disclosed herein are not limited to a 3GPP system.

[0034] 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.

[0035] Embodiments of the solutions described herein are described within the context of a 3GPP-based LTE network, i.e. an Evolved Packet System (EPS) including Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network (E-UTRAN) and Evolved Packet Core (EPC). However, the problems and solutions described herein are equally applicable to wireless access networks and UE implementing other access technologies and standards (e.g. a 5G system including 5G Core (5GC) and 5G radio access). LTE is used as an example technology where the embodiments of the solutions described herein are suitable. Since the embodiments of the solutions described herein are suitable for LTE, using LTE in the description therefore is particularly useful for understanding the problems and solutions disclosed herein for solving those problems. Furthermore, embodiments of the solutions described herein focus on the Isolated E- UTRAN Operations for Public Safety (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.

[0036] In some embodiments of the proposed solutions, systems and methods are disclosed herein that provide mechanisms to be implemented in the IOPS mode of operation to verify the availability of discovered Mission Critical (MC) UEs on the IOPS MC system. This improves the performance of the IOPS MC system since the notification to others MC UEs can be kept updated and valid. Note that the terms “MC UE” and “MC user” and “MC service UE” are used interchangeably herein. Also, a “MC UE” or “MC service UE” is more generally a wireless communication device, such as a UE, having a respective MC service client and IOPS connectivity client.

[0037] Figure 2 illustrates, in this regard, one example of a cellular communications system 200 in which embodiments of the present disclosure may be implemented. In the embodiments described herein, the cellular communications system 200 is an EPS including an LTE Radio Access Network (RAN) (i.e., an E-

UTRAN); however, the embodiments described herein are equally applicable to other types of cellular communications systems such as, e.g., a 5G system. In this example, the RAN includes base stations 202-1 and 202-2, which in LTE are referred to as eNBs, controlling corresponding (macro) cells 204-1 and 204-2. The base stations 202-1 and 202-2 are generally referred to herein collectively as base stations 202 and individually as base station 202. Likewise, the (macro) cells 204-1 and 204-2 are generally referred to herein collectively as

(macro) cells 204 and individually as (macro) cell 204. The RAN may also include a number of low power nodes 206-1 through 206-4 controlling corresponding small cells 208-1 through 208-4. The low power nodes

206-1 through 206-4 can be small base stations (such as pico or femto base stations) or Remote Radio Heads

(RRHs), or the like. Notably, while not illustrated, one or more of the small cells 208-1 through 208-4 may alternatively be provided by the base stations 202. The low power nodes 206-1 through 206-4 are generally referred to herein collectively as low power nodes 206 and individually as low power node 206. Likewise, the small cells 208-1 through 208-4 are generally referred to herein collectively as small cells 208 and individually as small cell 208. The cellular communications system 200 also includes a core network 210, which in the 5GS is referred to as the 5GC. The base stations 202 (and optionally the low power nodes 206) are connected to the core network 210.

[0038] The base stations 202 and the low power nodes 206 provide service to wireless communication devices 212-1 through 212-5 in the corresponding cells 204 and 208. The wireless communication devices 212-1 through 212-5 are generally referred to herein collectively as wireless communication devices 212 and individually as wireless communication device 212. In the following description, the wireless communication devices 212 are oftentimes UEs, but the present disclosure is not limited thereto.

[0039] While not illustrated, at least some of the base stations 202 and/or low power nodes 206 include or are connected to a local core (e.g., a Local EPC for LTE) and an IOPS MC system. As illustrated in Figure 1, the IOPS MC system includes an IOPS MC connectivity function and an IOPS distribution function. In the example embodiments described herein in which the cellular communications system 200 is an LTE system, the base stations 202 are eNBs, and one or more of these eNBs support IOPS (i.e., one or more of the eNBs are lOPS-capable eNBs). Further, using IOPS, the cellular communications system 200 together with the IOPS MC system support a MC service(s) (e.g., a MCPTT service) and enables the MC service(s) even in the case of backhaul failure by using the IOPS feature. Further, at least some of the wireless communication devices 212 are MC service devices (e.g., MC service UEs).

[0040] In this regard, the discussion now turns to some example embodiments implemented in an LTE system to provide MC service(s) (e.g., MC service(s) such as, e.g., MC Push to Talk (PTT) (MCPTT)) using IOPS to guarantee the MC service(s) even when there is a failure in the backhaul network (i.e., the network connecting the eNB(s) to the EPC).

[0041] Figure 3 illustrates, in this regard, one example architecture of an IOPS system for embodiments of the present disclosure. As illustrated, the architecture includes an IOPS connectivity function 300 and an IOPS distribution function 302. The architecture further includes an IOPS EPS including a local EPC 308 and an lOPS-enabled base station 310, and a MC service UE 312 including an MC service client 314 and an IOPS connectivity client 318. While illustrated separately for clarity and ease of discussion, it should be noted that the local EPC 308 may be implemented either separate from or within the IOPS enabled base station 310. Likewise, the IOPS MC system may be implemented either separate from or within the IOPS enabled base station 310.

[0042] Also note that the IOPS enabled base station 310 may be, e.g., any of the base stations 202 of

Figure 2. Likewise, the MC service UE 312 may be, e.g., any one of the UEs 212 of Figure 3. [0043] Lastly, while only one MC service UE 312 is illustrated in Figure 3, there can be many MC service UEs 312 using the IOPS MC system. To distinguish between such MC service UEs, the notation of MC service UE 312-X is used herein, where X may be, e.g., 1, 2, ..., N. Likewise, while only one IOPS enabled base station 310 is illustrated in Figure 3, there may be one or more IOPS enabled base stations 310 within the coverage area of the IOPS MC system (e.g., all base stations on an island).

4.1 Some Assumptions

[0044] Throughout the following 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 a “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 Identifier (ID)), and service configuration data or similar which is stored at the UE for off-network operation (the specific parameters are described in 3GPP TS 23.280 Annex A and 3GPP TS 23.379 Annex A for the MC services and MCPTT service U E/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.

[0045] 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.

[0046] In the case there is a link failure between the RAN (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 Internet Protocol (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.

4.2 User Availability Verification in IOPS

[0047] In one embodiment, when the IOPS MC connectivity function 300 has received an IOPS discovery request from the IOPS connectivity client 316 of the corresponding MC service UE 312, the IOPS MC connectivity function 300 includes within the corresponding IOPS discovery response an indication for the MC service UE 312 to transmit periodic IOPS discovery requests. The IOPS MC connectivity function 300 uses the periodic IOPS discovery requests to verify the availability of the MC service UE 312 and its IP connectivity information within the IOPS system.

[0048] In some embodiments, e.g., when desired or required, the IOPS MC connectivity function 300 modifies the IOPS discovery request periodicity and transmit a new IOPS discovery response to the MC service UE 312. For instance, when the IOPS MC connectivity function 300 detects that discovered MC UEs are not reachable due to moving often out from the IOPS system coverage area, the IOPS MC connectivity function 300 may modify the IOPS discovery request periodicity of those MC UEs or all discovered MC UEs and send respective new/modified IOPS discovery responses that indicate the modified IOPS discovery request periodicity.

[0049] Also, in some embodiments, the MC service UE 312 is able to send (e.g., at any time) a new IOPS discovery request to update or modify information, e.g. the user’s IP connectivity information, already published to the IOPS MC connectivity function 300 via a previous IOPS discovery request.

[0050] In one embodiment, the IOPS MC connectivity function 300 can send (e.g., at any time) an IOPS discovery response to the IOPS connectivity client 316 of the MC service UE 312 that indicates that the connectivity status of the corresponding MC service UE 312 is not discovered. This can be used by the IOPS MC connectivity function 300 to receive a new IOPS discovery request from the corresponding IOPS connectivity client 316 or for the case that the periodic IOPS discovery request has not been received yet.

Thus, the IOPS MC connectivity function 300 can verify the availability and IP connectivity information of the corresponding MC service UE 312 within the IOPS system.

[0051] In some embodiments, as described in 3GPP TS 23.180 v0.2.0, an MC service UE 312 can subscribe to the IOPS MC connectivity function 300 to receive notifications about other discovered MC service UEs available within the system. To provide notifications, the IOPS MC connectivity function 300 sends a notification request (via an IP connectivity notify request) to the IOPS connectivity client 316 of the corresponding MC service UE 312, and the IOPS connectivity client 316 responds via an IP connectivity notify response. Based on this and as an embodiment, if the IOPS MC connectivity function 300 does not receive the corresponding IP connectivity notify response, the IOPS MC connectivity function 300 transmits an IOPS discovery response to verify the availability and IP connectivity information of the corresponding MC service UE 312.

[0052] In some embodiments, if the IOPS MC connectivity function 300 does not receive the expected IP connectivity notify response nor a new IOPS discovery request (or the periodic IOPS discovery request) from the corresponding MC service UE 312 within a pre-defined time interval, the IOPS MC connectivity function 300 changes the registration of the corresponding MC service UE 312 to “not discovered” and notifies other discovered MC UEs with active subscriptions associated to the corresponding MC service UE 312 about the registration status change of the MC service UE 312. Thus, all discovered MC service UEs are properly notified about the availability of the discovered MC service UE 312 within the IOPS MC system.

[0053] Table 2.2-1 (also see e.g. Table 10.2.2.4-1 in the Appendix below) shows the new information flow message of the IOPS discovery response including the IOPS discovery request periodicity.

Table 2.2-1: IOPS discovery response

[0054] Section 2.2.1 (also see e.g. section 10.2.3 and Figure 10.2.3-2 in the Appendix below) describes the updated IOPS discovery procedure including this mechanism to verify the availability of a discovered MC service UE 312 in the IOPS mode of operation.

4.2.1 Updated IOPS Discovery Procedure

[0055] After an MC service UE 312 is authenticated on the IOPS MC connectivity function 300, the IOPS discovery procedure is initiated by the MC service UEs requesting support of the IP connectivity functionality to the IOPS MC connectivity function 300. If the IOPS MC connectivity function 300 indicates the support of the IP connectivity functionality, the MC service UEs can send an IOPS discovery request.

[0056] Figure 4 illustrates, in accordance with one example embodiment of the present disclosure, a procedure for requesting support of the IP connectivity functionality by the IOPS connectivity client 316 of the MC service UE 312 to the IOPS MC connectivity function 300. [0057] NOTE: The procedure for requesting support of the IP connectivity functionality is only required when the IOPS connectivity client 316 does not contain information about the support of this functionality by the serving IOPS MC connectivity function 300.

[0058] In some embodiments, the following pre-conditions are satisfied for the procedure of Figure 4:

• the MC service UE 312 is authenticated on the IOPS MC connectivity function 300;

• the MC service UE 312 has an active PDN connection to the IOPS MC connectivity function 300 for the specific IP connectivity functionality procedure; and

• the IOPS connectivity client 316 of the MC service UE 312 does not contain information about the support of the IP connectivity functionality by the serving IOPS MC connectivity function 300.

[0059] The steps of the procedure of Figure 4 are as follows:

• Step 400: The IOPS connectivity client 316 sends a request to the IOPS MC connectivity function 300 for the support of the IP connectivity functionality. This request is referred to herein as an IP connectivity request.

• Step 402: The IOPS MC connectivity function 302 sends a response to the IOPS connectivity client 316 that indicates to the IOPS connectivity client 316 whether the IP connectivity functionality is supported or not for the MC service UE 312.

[0060] Figure 5 illustrates a procedure for the discovery of MC service UEs in the IOPS mode of operation in accordance with one embodiment of the present disclosure. The IOPS discovery is initiated by the MC service UEs to support MC services based on the IP connectivity functionality.

[0061] In some embodiments, the following pre-conditions are satisfied for the procedure of Figure 5:

• the MC service UE 312 is authenticated on the IOPS MC connectivity function;

• the MC service UE 312 has an active PDN connection to the IOPS MC connectivity function for the specific IP connectivity functionality procedure; and

• the IOPS MC connectivity function 300 has indicated to the IOPS connectivity client 316 the support of the IP connectivity functionality.

[0062] The steps of the procedure of Figure 5 are as follows:

• Step 500: The IOPS connectivity client 316 of the MC service UE 312 sends an IOPS discovery request to the IOPS MC connectivity function 300. The request includes connectivity information for the support of MC services based on the IP connectivity functionality. • Step 502: The IOPS MC connectivity function 300 stores the connectivity information received from the MC service UE 312 and registers the connectivity status of the MC service UE 312 (or equivalently the user of the MC service UE 312) as “discovered”.

• Step 504: The IOPS MC connectivity function 300 provides a response to the IOPS connectivity client 316 indicating the success or failure of the discovery of the requesting MC service UE 312. As discussed above, the IOPS discovery response includes a periodicity that the IOPS connectivity client 316 is to use for sending again (i.e., resending) an IOPS discovery request. In this example embodiment, the periodicity indicated in the IOPS discovery response serves as an indication for the MC service UE 312 to transmit periodic IOPS discovery requests at the indicated periodicity. Note that any of the embodiments described above may be used in relation to including the periodicity in the IOPS discovery response.

[0063] NOTE 1: As discussed above, in some embodiments, the MC service UE 312 sends a new IOPS discovery request to update or modify the connectivity information (e.g., to update or modify information element(s) used to provide the connectivity information).

[0064] NOTE 2: As discussed above, in some embodiments, the IOPS MC connectivity function 300 can send an IOPS discovery response to the IOPS connectivity client 316 indicating that the connectivity status of the corresponding MC service UE 312 is not discovered. This can be used by the IOPS MC connectivity function 300 to receive (e.g., to trigger) a new IOPS discovery request from the corresponding IOPS connectivity client 316 or for the case that the periodic IOPS discovery request has not been received yet.

Thus, the IOPS MC connectivity function 300 can verify the availability and IP connectivity information of the MC service UE 312 within the IOPS system.

[0065] Figure 6 illustrates the operation of the IOPS connectivity client 316 of a particular MC service UE 312 and the IOPS connectivity function 300 in accordance with at least some aspects of the embodiments described above. Optional steps are represented by dashed lines/boxes. As illustrated, the IOPS connectivity client 316 sends an IOPS discovery request to the IOPS connectivity function 300, as described above (step 600). The IOPS connectivity function 300 stores the connectivity information received in the IOPS discovery request and sets the status, or registration, of the MC service UE 312 to “discovered” (step 602). The IOPS connectivity function 300 sends an IOPS discovery response including a periodicity indication to the IOPS connectivity client 316 (step 604). The IOPS connectivity client 316 sends a new IOPS discovery request to the IOPS connectivity function 300 at the indicated periodicity, as described above (step 606). This new IOPS discovery request may, in some embodiments, contain updated or modified connectivity information, as described above. The IOPS connectivity function 300 monitors for such periodic IOPS discovery requests from the IOPS connectivity client 316. Upon receiving the IOPS discovery request in step 606, the IOPS connectivity function 300 stores the updated/modified connectivity information, if any (step 608). The status of the MC service UE 312 remains “discovered”. The IOPS connectivity function 300 sends an IOPS discovery response including a periodicity indication to the IOPS connectivity client 316 (step 610). As discussed above, in some embodiments, the periodicity indicated in the response of step 610 may be the same periodicity as that indicated in step 604 or may be a different periodicity (e.g., if the IOPS connectivity function 300 has decided to change the periodicity for IOPS discovery requests). The process continues in this manner as the IOPS connectivity client 316 continues to sends IOPS discovery requests at the indicated periodicity.

[0066] At some point, the IOPS connectivity function 300 determines that an IOPS discovery request has not been received from the IOPS connectivity client 316 (e.g., has not been received within an amount of time defined by the indicated periodicity) (step 612). As such, the IOPS connectivity function 300 updates the status of the MC service UE 612 to “not discovered” and notifies other discovered MC service UEs of the new status of the MC service UE 612, as described above (steps 614 and 616). The IOPS MC connectivity function 300 may send, to the IOPS connectivity client 316, an indication that the status of the MC service UE 312 is unknown (step 618). For example, the IOPS connectivity function 300 may send a message to the IOPS connectivity client 316 that triggers the IOPS connectivity client 316 to send a new IOPS discovery request. If this indication is received by the IOPS connectivity client 316, the IOPS connectivity client 316 sends a new IOPS discovery request to the IOPS connectivity function 300 (step 620), and the procedure may continue as described above.

4.3 Further Aspects

[0067] Figure 7 is a schematic block diagram of a radio access node 700 according to some embodiments of the present disclosure. Optional features are represented by dashed boxes. The radio access node 700 may be, for example, a base station 202 or 206 or a network node that implements all or part of the functionality of the base station 202 or eNB described herein. In particular, all or part of the functionality of the IOPS connectivity function 300 described above (e.g., with respect to Figures 4 through 6) may be implemented in the radio access node 700, in some embodiments. As illustrated, the radio access node 700 includes a control system 702 that includes one or more processors 704 (e.g., Central Processing Units (CPUs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and/or the like), memory 706, and a network interface 708. The one or more processors 704 are also referred to herein as processing circuitry. In addition, the radio access node 700 may include one or more radio units 710 that each includes one or more transmitters 712 and one or more receivers 714 coupled to one or more antennas 716. The radio units 710 may be referred to or be part of radio interface circuitry. In some embodiments, the radio unit(s) 710 is external to the control system 702 and connected to the control system 702 via, e.g., a wired connection (e.g., an optical cable). However, in some other embodiments, the radio unit(s) 710 and potentially the antenna(s) 716 are integrated together with the control system 702. The one or more processors 704 operate to provide one or more functions of a radio access node 700 as described herein. In some embodiments, the function(s) are implemented in software that is stored, e.g., in the memory 706 and executed by the one or more processors 704.

[0068] Figure 8 is a schematic block diagram that illustrates a virtualized embodiment of the radio access node 700 according to some embodiments of the present disclosure. This discussion is equally applicable to other types of network nodes. Further, other types of network nodes may have similar virtualized architectures. Again, optional features are represented by dashed boxes.

[0069] As used herein, a “virtualized” radio access node is an implementation of the radio access node 700 in which at least a portion of the functionality of the radio access node 700 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 radio access node 700 may include the control system 702 and/or the one or more radio units 710, as described above. The control system 702 may be connected to the radio unit(s) 710 via, for example, an optical cable or the like. The radio access node 700 includes one or more processing nodes 800 coupled to or included as part of a network(s) 802. If present, the control system 702 or the radio unit(s) are connected to the processing node(s) 800 via the network 802. Each processing node 800 includes one or more processors 804 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 806, and a network interface 808.

[0070] In this example, functions 810 of the radio access node 700 described herein (e.g., all or part of the functionality of the IOPS connectivity function 300 described above (e.g., with respect to Figures 4 through 6)) are implemented at the one or more processing nodes 800 or distributed across the one or more processing nodes 800 and the control system 702 and/or the radio unit(s) 710 in any desired manner. In some particular embodiments, some or all of the functions 810 of the radio access node 700 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) 800. As will be appreciated by one of ordinary skill in the art, additional signaling or communication between the processing node(s) 800 and the control system 702 is used in order to carry out at least some of the desired functions 810. Notably, in some embodiments, the control system 702 may not be included, in which case the radio unit(s) 710 communicate directly with the processing node(s) 800 via an appropriate network interface(s).

[0071] 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 radio access node 700 or a node (e.g., a processing node 800) implementing one or more of the functions 810 of the radio access node 700 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).

[0072] Figure 9 is a schematic block diagram of the radio access node 700 according to some other embodiments of the present disclosure. The radio access node 700 includes one or more modules 900, each of which is implemented in software. The module(s) 900 provide the functionality of the radio access node 700 described herein (e.g., all or part of the functionality of the IOPS connectivity function 300 described above (e.g., with respect to Figures 4 through 6)). This discussion is equally applicable to the processing node 800 of Figure 8 where the modules 900 may be implemented at one of the processing nodes 800 or distributed across multiple processing nodes 800 and/or distributed across the processing node(s) 800 and the control system 702.

[0073] Figure 10 is a schematic block diagram of a wireless communication device 1000 according to some embodiments of the present disclosure. The wireless communication device 1000 is one example of the wireless communication device 212. In some embodiments, the wireless communication device 1000 is a MC service device (e.g., a MC service UE 312). As illustrated, the wireless communication device 1000 includes one or more processors 1002 (e.g., CPUs, ASICs, FPGAs, and/or the like), memory 1004, and one or more transceivers 1006 each including one or more transmitters 1008 and one or more receivers 1010 coupled to one or more antennas 1012. The transceiver(s) 1006 includes radio-front end circuitry connected to the antenna(s) 1012 that is configured to condition signals communicated between the antenna(s) 1012 and the processor(s) 1002, as will be appreciated by on of ordinary skill in the art. The processors 1002 are also referred to herein as processing circuitry. The transceivers 1006 are also referred to herein as radio circuitry.

In some embodiments, the functionality of the wireless communication device 1000 described above (e.g., all or part of the functionality the MC service UE described above with respect to, e.g., Figures 4 to 6) may be fully or partially implemented in software that is, e.g., stored in the memory 1004 and executed by the processor(s)

1002. Note that the wireless communication device 1000 may include additional components not illustrated in

Figure 10 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 1000 and/or allowing output of information from the wireless communication device 1000), a power supply (e.g., a battery and associated power circuitry), etc.

[0074] 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 1000 according to any of the embodiments described herein (e.g., all or part of the functionality the MC service UE 312 described above with respect to, e.g., Figures 4 to 6) 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).

[0075] Figure 11 is a schematic block diagram of the wireless communication device 1000 according to some other embodiments of the present disclosure. The wireless communication device 1000 includes one or more modules 1100, each of which is implemented in software. The module(s) 1100 provide the functionality of the wireless communication device 1000 described herein (e.g., all or part of the functionality the MC service UE 312 described above with respect to, e.g., Figures 4 to 6).

[0076] 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.

[0077] 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.). 5 SOME EMBODIMENTS DESCRIBED ABOVE MAY BE SUMMARIZED IN THE FOLLOWING MANNER:

1. A method performed by an IOPS connectivity client (316) of a wireless communication device (312), the method comprising: sending (400) a request to an IOPS connectivity function (300) of an IOPS system, the request being a request for an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality; and receiving (402) a response from the IOPS connectivity function (300), the response comprising an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality.

2. A method performed by an IOPS connectivity client (316) of a wireless communication device (312), the method comprising: sending (500; 600) an IOPS discovery request to an IOPS connectivity function (300) of an IOPS system; and receiving (502; 604) an IOPS discovery response from the IOPS connectivity function (300), the IOPS discovery response comprising information that indicates that the IOPS connectivity client (316) is to periodically transmit IOPS discovery requests.

3. The method of embodiment 2 further comprising periodically transmitting IOPS discovery requests in accordance with information comprised in the IOPS discovery response.

4. The method of embodiment 2 wherein the information comprised in the IOPS discovery response comprises an indication of a periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

5. The method of embodiment 4 further comprising: transmitting (606) a second IOPS discovery request to the IOPS connectivity function (300) of the IOPS system in accordance with the indicated periodicity.

6. The method of any of embodiments 2 to 5 further comprising: receiving (618), from the IOPS connectivity function (300), an indication that a status of the wireless communication device (312) is unknown; and in response to receiving (618) the indication that the status of the wireless communication device (312) is unknown, sending (620) an IOPS discovery request to the IOPS connectivity function (300).

7. The method of any of embodiments 1 to 6 wherein the wireless communication device (312) is a MC service enabled wireless communication device (312).

8. A wireless communication device (312; 1000) adapted to perform the method of any of embodiments 1 to 7.

9. A wireless communication device (312; 1000) comprising: one or more transmitters (1008); one or more receivers (1010); and processing circuitry (1002) associated with the one or more transmitters (1008) and the one or more receivers (1010), the processing circuitry (1002) configured to cause the wireless communication device (212;

1000) to perform the method of any of embodiments 1 to 7.

10. A method performed by a network node that implements an IOPS connectivity function (300) of an IOPS system, the method comprising: receiving (400) a request from an IOPS connectivity client (316) of wireless communication device (312), the request being a request for an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality; and sending (402) a response to the IOPS connectivity client (316), the response comprising an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality.

11. A method performed by a network node that implements an IOPS connectivity function (300) of an IOPS system, the method comprising: receiving (500; 600) an IOPS discovery request from an IOPS connectivity client (316) of a wireless communication device (312); and sending (502; 604) an IOPS discovery response to the IOPS connectivity client (316), the IOPS discovery response comprising information that indicates that the IOPS connectivity client (316) is to periodically transmit IOPS discovery requests. 12. The method of embodiment 11 further comprising, in response to receiving (500; 600) the IOPS discovery request, setting (502) a status or registration of the wireless communication device (312) in the IOPS system as discovered.

13. The method of embodiment 11 wherein the IOPS discovery request comprises connectivity information, and the method further comprises storing (502) the connectivity information.

14. The method of any of embodiments 11 to 13 further comprising monitoring (606) for periodic IOPS discovery requests from the IOPS connectivity client (316) in accordance with the information comprised in the IOPS discovery response.

15. The method of any of embodiments 11 to 13 wherein the information comprised in the IOPS discovery response comprises an indication of a periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

16. The method of embodiment 15 further comprising sending (e.g., in another IOPS discovery response) to the IOPS connectivity client (316) information that indicates a new periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

17. The method of embodiment 15 or 16 further comprising receiving (606) a second IOPS discovery request from the IOPS connectivity client (316) in accordance with the indicated periodicity.

18. The method of embodiment 17 further comprising sending (610) a second IOPS discovery response to the IOPS connectivity client (316).

19. The method of embodiment 18 wherein the second IOPS discovery response comprises information that indicates a new periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

20. The method of any of embodiments 11 to 19 further comprising: determining (612) that an IOPS discovery request has not been received from the IOPS connectivity client (316) in accordance with the information comprised in the IOPS discovery response; and upon determining (612) that an IOPS discovery request has not been received from the IOPS connectivity client (316) in accordance with the information comprised in the IOPS discovery response, setting a status of the wireless communication device (312) in the IOPS system as not discovered.

21. The method of embodiment 20 further comprising notifying (616) one or more other wireless communication devices in the IOPS system of the status of the wireless communication system (312) in the IOPS system being not discovered.

22. The method of embodiment 20 or 21 further comprising sending (618), to the IOPS connectivity client (316), an indication that a status of the wireless communication device (312) is unknown.

23. The method of embodiment 22 further comprising, in response to sending (618) the indication that the status of the wireless communication device (312) is unknown, receiving (620) an IOPS discovery request from the IOPS connectivity client (316).

24. The method of any of embodiments 11 to 23 wherein the wireless communication device (312) is a MC service enabled wireless communication device (312).

25. A network node (700) that implements an IOPS connectivity function (300) of an IOPS system, the network node (700) adapted to perform the method of any of embodiments 11 to 24.

26. A network node (700) that implements an IOPS connectivity function (300) of an IOPS system, the network node (700) comprising: processing circuitry (704; 804) configured to cause the network node (700) to perform the method of any of embodiments 11 to 24.

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

AMF Access and Mobility Function

AUSF Authentication Server Function eNB Enhanced or Evolved Node B

EPC Evolved Packet Core

EPS Evolved Packet System

E-UTRAN Evolved Universal Mobile Telecommunications System Terrestrial Radio Access Network

GC Group Communication gNB New Radio Base Station

HSS Flome Subscriber Server

IOPS Isolated Evolved Universal Mobile Telecommunications System Terrestrial Radio

Access Network Operations for Public Safety loT Internet of Things

IP Internet Protocol

LTE Long Term Evolution

MC Mission Critical

MCData Mission Critical Data

MCPTT Mission Critical Push to Talk

MCVideo Mission Critical Video

MME Mobility Management Entity

MTC Machine Type Communication

NEF Network Exposure Function

NF Network Function

NPN Non-Public Network

NR New Radio

NRF Network Function Repository Function NSSF Network Slice Selection Function

PCF Policy Control Function

P-GW Packet Data Network Gateway

ProSe Proximity Services

PTT Push to Talk

RAN Radio Access Network

SCEF Service Capability Exposure Function

S-GW Serving Gateway

SMF Session Management Function

TS Technical Specification

UDM Unified Data Management

UE User Equipment

UMTS Universal Mobile Telecommunications System

UPF User Plane Function

Appendix

3GPP TSG-SA WG6 Meeting #35 S6-200094 Hyderabad, India, 13^th - 17^th Jan 2020 (revision of S6-20xxxx)

Source: Ericsson

Title: Pseudo-CR on IOPS discovery update

Spec: 3GPP TS 23.180 v0.2.0

Agenda item: 10.2 Document for: Approval Contact: Camilo Solano (camilo.solano@ericsson.com)

1. Introduction

The IP connectivity functionality includes an IOPS discovery procedure. The IOPS discovery procedure contains to steps. Firstly, a user requests to the IOPS MC connectivity function the support of the IP connectivity functionality. Once a user has been indicated the support of the IP connectivity functionality, the user can send a discovery request.

This contribution updates the discovery procedure and splits it into two procedures.

2. Reason for Change

With the current procedure, every time a user sends a discovery request to the IOPS MC connectivity function, the user first sends an IP connectivity request. However, if the user has already been indicated that the IP connectivity functionality is supported by the IOPS MC connectivity function, then the user can directly send a discovery request.

3. Conclusions

4. Proposal

It is proposed to approve the following changes to 3GPP TS 23.180 v0.2.0.

10.2 IOPS discovery (IP connectivity functionality)

10.2.1 General

The support of the IP connectivity functionality in the IOPS mode of operation enables that MC services are provided by the MC service clients operating on the MC service UEs via the IOPS MC connectivity function. An IOPS MC connectivity lunction provides IP connectivity for the communication among MC service users based on an IOPS discovery procedure.

The IOPS discovery procedure enables that the IOPS MC connectivity lunction discovers MC service users within the coverage of the system and receives connectivity information required to establish a communication between discovered users based on the IP connectivity functionality. The following clauses specify the IOPS discovery procedure and information flows for the IP connectivity functionality in the IOPS mode of operation.

10.2.2 Information flows

10.2.2.1 IP connectivity request

Table 10.2.2.1-1 describes the information flow for the IP connectivity request from the IOPS connectivity client to the IOPS MC connectivity function.

Table 10.2.2.1-1 : IP connectivity request

10.2.2.2 IP connectivity response

Table 10.2.2.2-1 describes the information flow for the IP connectivity response from the IOPS MC connectivity function to the IOPS connectivity client.

Table 10.2.2.2-1 : IP connectivity response

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 10.2.2.4 IOPS discovery response

Table 10.2.2.4-1 describes the information flow for the IOPS discovery response from the IOPS MC connectivity function to the IOPS connectivity client.

Table 10.2.2.4-1: IOPS discovery response

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 fP 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: 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 function the support of the fP 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.

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. The IOPS discovery response includes an indication of a periodicity at which the IOPS connectivity client is required to transmit IOPS discovery requests.

NOTE 1 : The MC user shall send a new IOPS discovery request to update or modify information elements.

NOTE 2: 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. The IOPS MC connectivity function can verify the availability and IP connectivity information of the MC user within the IOPS system.

Claims

CLAIMS What is claimed is:

3. The method of claim 2 further comprising periodically transmitting IOPS discovery requests in accordance with information comprised in the IOPS discovery response.

4. The method of claim 2 wherein the information comprised in the IOPS discovery response comprises an indication of a periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

5. The method of claim 4 further comprising: transmitting (606) a second IOPS discovery request to the IOPS connectivity function (300) of the IOPS system in accordance with the indicated periodicity.

6. The method of any of claim 2 to 5 further comprising: receiving (618), from the IOPS connectivity function (300), an indication that a status of the wireless communication device (312) is unknown; and in response to receiving (618) the indication that the status of the wireless communication device (312) is unknown, sending (620) an IOPS discovery request to the IOPS connectivity function (300).

7. The method of any of claim 1 to 6 wherein the wireless communication device (312) is a MC service enabled wireless communication device (312).

8. A wireless communication device (312; 1000) adapted to perform the method of any of claim 1 to 7.

1000) to perform the method of any of claim 1 to 7.

10. A method performed by a network node that implements an IOPS connectivity function (300) of an IOPS system, the method comprising: receiving (400) a request from an IOPS connectivity client (316) of a wireless communication device (312), the request being a request for an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality; and sending (402) a response to the IOPS connectivity client (316), the response comprising an indication of whether the IOPS connectivity function (300) supports IP connectivity functionality.

11. A method performed by a network node that implements an IOPS connectivity function (300) of an IOPS system, the method comprising: receiving (500; 600) an IOPS discovery request from an IOPS connectivity client (316) of a wireless communication device (312); and sending (502; 604) an IOPS discovery response to the IOPS connectivity client (316), the IOPS discovery response comprising information that indicates that the IOPS connectivity client (316) is to periodically transmit IOPS discovery requests.

12. The method of claim 11 further comprising, in response to receiving (500; 600) the IOPS discovery request, setting (502) a status or registration of the wireless communication device (312) in the IOPS system as discovered.

13. The method of claim 11 wherein the IOPS discovery request comprises connectivity information, and the method further comprises storing (502) the connectivity information.

14. The method of any of claim 11 to 13 further comprising monitoring (606) for periodic IOPS discovery requests from the IOPS connectivity client (316) in accordance with the information comprised in the IOPS discovery response.

15. The method of any of claim 11 to 13 wherein the information comprised in the IOPS discovery response comprises an indication of a periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

16. The method of claim 15 further comprising sending (e.g., in another IOPS discovery response) to the IOPS connectivity client (316) information that indicates a new periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

17. The method of claim 15 or 16 further comprising receiving (606) a second IOPS discovery request from the IOPS connectivity client (316) in accordance with the indicated periodicity.

18. The method of claim 17 further comprising sending (610) a second IOPS discovery response to the IOPS connectivity client (316).

19. The method of claim 18 wherein the second IOPS discovery response comprises information that indicates a new periodicity at which the IOPS connectivity client (316) is to transmit IOPS discovery requests.

20. The method of any of claim 11 to 19 further comprising: determining (612) that an IOPS discovery request has not been received from the IOPS connectivity client (316) in accordance with the information comprised in the IOPS discovery response; and upon determining (612) that an IOPS discovery request has not been received from the IOPS connectivity client (316) in accordance with the information comprised in the IOPS discovery response, setting a status of the wireless communication device (312) in the IOPS system as not discovered.

21. The method of claim 20 further comprising notifying (616) one or more other wireless communication devices in the IOPS system of the status of the wireless communication system (312) in the IOPS system being not discovered.

22. The method of claim 20 or 21 further comprising sending (618), to the IOPS connectivity client (316), an indication that a status of the wireless communication device (312) is unknown.

23. The method of claim 22 further comprising, in response to sending (618) the indication that the status of the wireless communication device (312) is unknown, receiving (620) an IOPS discovery request from the IOPS connectivity client (316).

24. The method of any of claim 11 to 23 wherein the wireless communication device (312) is a MC service enabled wireless communication device (312).

25. A network node (700) that implements an IOPS connectivity function (300) of an IOPS system, the network node (700) adapted to perform the method of any of claim 11 to 24.

26. A network node (700) that implements an IOPS connectivity function (300) of an IOPS system, the network node (700) comprising: processing circuitry (704; 804) configured to cause the network node (700) to perform the method of any of claim 11 to 24.