WO2022031106A1

WO2022031106A1 - Method and apparatus for prose group management in wireless communication system

Info

Publication number: WO2022031106A1
Application number: PCT/KR2021/010404
Authority: WO
Inventors: Mehrdad Shariat; Mahmoud Watfa; Andrew Bennett
Original assignee: Samsung Electronics Co., Ltd.
Priority date: 2020-08-07
Filing date: 2021-08-06
Publication date: 2022-02-10
Also published as: GB2601396A; GB202110712D0; GB2601396A9

Abstract

The present disclosure refers to a method and apparatus for managing ProSe group efficently in wirless communication system. The method of managing a network is described. The network comprises a set of user equipment, UEs. The method comprises: establishing, by the set of UEs, a Proximity Services, ProSe, group comprising the set of UEs; groupcasting, by the set of UEs, to the established ProSe group; and managing, by the set of UEs, the established ProSe group at a ProSe application layer, AL, optionally in coordination with a ProSe Application Server, AS. A network is also described.

Description

METHOD AND APPARATUS FOR PROSE GROUP MANAGEMENT IN WIRELESS COMMUNICATION SYSTEM

The present disclosure relates to the Group management for interactive Proximity Services (ProSe).

To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a 'Beyond 4G Network' or a 'Post LTE System'. The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems. In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like. In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access(NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.

The Internet, which is a human centered connectivity network where humans generate and consume information, is now evolving to the Internet of Things (IoT) where distributed entities, such as things, exchange and process information without human intervention. The Internet of Everything (IoE), which is a combination of the IoT technology and the Big Data processing technology through connection with a cloud server, has emerged. As technology elements, such as "sensing technology", "wired/wireless communication and network infrastructure", "service interface technology", and "Security technology" have been demanded for IoT implementation, a sensor network, a Machine-to-Machine (M2M) communication, Machine Type Communication (MTC), and so forth have been recently researched. Such an IoT environment may provide intelligent Internet technology services that create a new value to human life by collecting and analyzing data generated among connected things. IoT may be applied to a variety of fields including smart home, smart building, smart city, smart car or connected cars, smart grid, health care, smart appliances and advanced medical services through convergence and combination between existing Information Technology (IT) and various industrial applications.

In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as a sensor network, Machine Type Communication (MTC), and Machine-to-Machine (M2M) communication may be implemented by beamforming, MIMO, and array antennas. Application of a cloud Radio Access Network (RAN) as the above-described Big Data processing technology may also be considered to be as an example of convergence between the 5G technology and the IoT technology.

Proximity Services (ProSe) (specifically the direct communication) have been enhanced to support Vehicle-to-Everything (V2X) services over LTE. For Fifth Generation Systems (5GS), the proximity services are expected to be an important system wide enabler to support various applications and services including public safety.

The present disclosure provides a method and apparatus for managing ProSe group efficently in wirless communication system.

A first aspect provides a method of managing a network comprising a set of user equipment, UEs, the method comprising:

establishing, by the set of UEs, a Proximity Services, ProSe, group comprising the set of UEs;

groupcasting, by the set of UEs, to the established ProSe group; and

managing, by the set of UEs, the established ProSe group at a ProSe application layer, AL, optionally in coordination with a ProSe Application Server, AS.

wherein establishing the ProSe group comprises providing, by the ProSe AL, a group identifier to the set of UEs.

wherein establishing the ProSe group comprises performing, by the respective UEs of the set thereof, group discovery using the provided group identifier by exchanging application discovery messages, optionally wherein establishing the ProSe group is restricted to UEs of the set thereof having the same group identifier provided thereto.

wherein exchanging the application discovery messages comprises exchanging the application discovery messages over a PC5 reference point between the UEs of the set thereof.

wherein establishing the ProSe group comprises selecting, by the respective UEs of the set thereof, respective source identifiers based on the provided group identifier and optionally, determining respective destination identifiers based on the provided group identifier.

wherein establishing the ProSe group comprises providing group identifier information to the respective UEs of the set thereof, optionally wherein the group identifier information comprises group member identifiers and/or a group size.

The method further comprising assigning, via the ProSe AS, a group lead UE from the established ProSe group.

The method further comprising reassigning, via the ProSe AS, the group lead UE from the established ProSe group.

The method further comprising reassigning, via the ProSe AS, the group lead UE from the established ProSe group is in response to receiving, from the group lead UE, a message indicating an intention of the group lead UE to leave the established ProSe group or become out-of-coverage.

The method further comprising reassigning, via the ProSe AS, the group lead UE from the established ProSe group comprises updating, via the ProSe AS, the established ProSe group thereupon.

The method further comprising comprising transmitting, by an out-of-coverage UE of the established ProSe group, a message to the established ProSe group, wherein the message indicates an intention of the out-of-coverage UE to leave the established ProSe group and providing, by the group lead UE, the message to the ProSe AS, in response to receiving the transmitted message.

The method further comprising comprising updating, via the ProSe AS and/or the group lead UE, the remaining UEs of the established ProSe group.

The method further comprising comprising joining, by a new UE, the established ProSe group and optionally transmitting by the group lead UE, a message to an out-of-coverage UE of the established ProSe group, in response to joining, by the new UE, the established ProSe group.

The method further comprising comprising transmitting, by an out-of-coverage UE of the established ProSe group, a message to the established ProSe group, wherein the message comprises a coverage report.

The method further comprising comprising providing, by the group lead UE to the established ProSe group, an update to group identifier information, in response to receiving the message.

The method further comprising determining a destination layer 2 identifier based on a mapping provisioned by the AS.

The method further comprising amending or deleting, by the ProSe AS, ProSe parameters provisioned via a path and/or a source (e.g. 5GC) within a Unified Data Repository, UDR, such that the ProSe parameters provisioned from another path and/or another source take effect.

The method further comprising updating, via the ProSe AS, a path for providing a group identifier to the set of UEs.

wherein the ProSe AS is integrated with a 5G Direct Discovery Name Management Function, 5G DDNMF.

A second aspect provides a network comprising a set of user equipment, UEs, wherein the network is configured to:

establish, by the set of UEs, a Proximity Services, ProSe, group comprising the set of UEs;

groupcast, by the set of UEs, to the established ProSe group; and

manage, by the set of UEs, the established ProSe group at a ProSe application layer, AL, optionally in coordination with a ProSe Application Server, AS.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "couple" and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms "transmit," "receive," and "communicate," as well as derivatives thereof, encompass both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and/or. The phrase "associated with," as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term "controller" means any device, system or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase "at least one of," when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, "at least one of: A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms "application" and "program" refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase "computer readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer readable medium" includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A "non-transitory" computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughout this disclosure. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

For a better understanding of the disclosure, and to show how exemplary embodiments of the same may be brought into effect, reference will be made, by way of example only, to the accompanying diagrammatic Figures, in which:

Figure 1 shows a baseline group management, group discovery and group communication, according to an exemplary embodiment;

Figure 2 shows a representation of a call flow according to an exemplary embodiment;

Figure 3 shows a representation of a call flow according to an exemplary embodiment;

Figure 4 shows a representation of a call flow according to an exemplary embodiment; and

Figure 5 shows a representation of a call flow according to an exemplary embodiment.

Figure 6 shows a block diagram of a UE performing operations according to an embodiment, and

Figure 7 shows a block diagram of a network entity performing operations according to an embodiment.

Hereinafter, embodiments of the disclosure are described in detail with reference to the accompanying drawings.

In describing embodiments, the description of technologies that are known in the art and are not directly related to the disclosure is omitted. This is for further clarifying the gist of the disclosure without making it unclear.

For the same reasons, some elements may be exaggerated or schematically shown. The size of each element does not necessarily reflects the real size of the element. The same reference numeral is used to refer to the same element throughout the drawings.

Advantages and features of the disclosure, and methods for achieving the same may be understood through the embodiments to be described below taken in conjunction with the accompanying drawings. However, the disclosure is not limited to the embodiments disclosed herein, and various changes may be made thereto. The embodiments disclosed herein are provided only to inform one of ordinary skilled in the art of the category of the disclosure. The disclosure is defined only by the appended claims. The same reference numeral denotes the same element throughout the specification. When determined to make the subject matter of the disclosure unclear, the detailed description of the known art or functions may be skipped. The terms as used herein are defined considering the functions in the disclosure and may be replaced with other terms according to the intention or practice of the user or operator. Therefore, the terms should be defined based on the overall disclosure.

Hereinafter, the base station may be an entity communicating with the UE and may be at least one of a (R)AN(radio access network), gNB, eNB, Node B, base station (BS), access point (AP), wireless access unit, base station controller, or node over network. The UE may be at least one of a user equipment (UE), a mobile station (MS), a terminal, a cellular phone, a smart phone, a smart watch, a wearable device, a computer, and various multimedia devices capable of performing a communication function. In the disclosure, downlink (DL) refers to a wireless transmission path of signals transmitted from the base station to the UE, and uplink (UL) refers to a wireless transmission path of signals transmitted from the UE to the base station. Although the LTE or LTE-A systems may be described below as an example, embodiments of the disclosure may be applied to other communication systems having a similar technical background or channel shape. For example, 5G mobile communication technology (5G, new radio, NR) developed after LTE-A may be included therein, and 5G below may be a concept including legacy LTE, LTE-A and other similar services. Further, embodiments of the disclosure may be modified in such a range as not to significantly depart from the scope of the disclosure under the determination by one of ordinary skill in the art and such modifications may be applicable to other communication systems.

Class of commercial services related to ProSe has recently emerged termed as Network-controlled Interactive services (NCIS) that share some commonality of requirements with public safety services and applications. NCIS refers to a kind of service which needs at least 2 UEs to join and share data, e.g. interactive gaming or data sharing.

For either public safety or NCIS services, a group can be determined externally at application layer (e.g. via coordination with a ProSe Application Server) where the UEs grouped form the same public safety or NCIS session together.

The ProSe group management may happen at the ProSe Application Server. For group communication over PC5 reference point, the application server (via the application layer) may provide group identifier information (e.g. application-layer group ID, ProSe Layer-2 Group ID, group member ID or group size) over PC1 reference point to the UEs. Then, the group identifier information is passed to ProSe layer of each UE and is converted into a destination Layer-2 ID used for groupcast communication at Access stratum level.

When the group identifier information is not provided by the ProSe application layer, the UE may determine the destination Layer-2 ID based on configuration of the mapping between ProSe service type and Layer-2 ID. Such configuration information can be provided from policy control function (PCF). Alternatively, the mobile network operator may pre-configure the UEs (e.g. in Universal integrated circuit card- UICC or Mobile Equipment- ME) with the required mapping information, without the need for the UEs to connect to the 5GC. This option can be in particular useful for public safety applications with known and established service types.

When it comes to commercial applications like NCIS, group identifier information can be more temporarily and dynamically assigned in an on-demand manner. The UEs may not always be pre-configured for required mapping information. Such dynamic identifier information may have limited validity time, subject to expiry. Frequent sharing of such information via PCF may result in control-plane level network congestion. Another challenge is, part of the UEs intended as group members may temporarily move out of coverage of the network (while still in proximity of other group members to continue the ProSe group communications). Without access to either the ProSe Application Server or 5GC to receive up-to-date dynamic group identifier information, such UEs are obliged to leave the group.

Hence, there is a need to improve ProSe.

According to the present disclosure there is provided a method, as set forth in the appended claims. Also provided is a network. Other features of the disclosure will be apparent from the dependent claims, and the description that follows.

The first aspect provides a method of managing a network comprising a set of user equipment, UEs, the method comprising:

groupcasting, by the set of UEs, to the established ProSe group; and

Additionally and/or alternatively, according to the present disclosure, there is provided a method of group management in a system where a 5G DDNMF entity and/or the ProSe Application server may assist on group management.

To address the above challenges, the method according to the first aspect provides:

1. On demand group identifier management (e.g. for commercial/ NCIS applications) to be handled by a 5G Direct Discovery Name Management Function (DDNMF) per PLMN and/or ProSe Application Server (i.e. either in data plane over a direct interface between 5G DDNMF and UEs, e.g. PC3-like reference point or via coordination with ProSe Application Server and then via PC1 reference point between application server and UEs).This is in addition to the PCF-based provisioning that can be triggered by ProSe Application Server. Here, ProSe Application Server may determine the path (PC1, PC3, or PCF-based) to provision the group identifiers (along any other policy /parameters) to the UE based on different criteria (e.g. based on the level of load on each interface). ProSe Application Server ensures that parameters to be shared across different paths are not in conflict (e.g. by avoiding to provide the same set of parameters from multiple paths unless the precedence is predefined).

2. When UEs in a group session move temporarily out of coverage, a UE still in coverage within the group (termed as the group lead UE, i.e. an initiating UE) may facilitate a delegated group identifier management (i.e. exchanging application discovery messages) over PC5 reference point via updating application layer group identifiers among intended group members. For such delegated group information update, the source Layer-2 ID is self-selected by each member UE intending to use delegated group information update. A specific Destination Layer-2 ID for sharing delegated group identifier information is determined based on a mapping provisioned by 5G DDNMF in coordination with application layer (when UE joins the group). This is different from the destination Layer-2 ID used for groupcast communication. A message type field within group information update message indicates that the payload is related to delegated group identifier management to distinguish it from other direct discovery messages. This is to be identified at the ProSe application layer of the UE. The message type field can be transparent to Access Stratum.

In one example, establishing the ProSe group comprises providing, by the ProSe AL, a group identifier to the set of UEs.

In one example, establishing the ProSe group comprises performing, by the respective UEs of the set thereof, group discovery using the provided group identifier by exchanging application discovery messages, optionally wherein establishing the ProSe group is restricted to UEs of the set thereof having the same group identifier provided thereto.

In one example, exchanging the application discovery messages comprises exchanging the application discovery messages over a PC5 reference point between the UEs of the set thereof.

In a preferred embodiment of the disclosure, there is provided one or more of enhanced signalling procedures, for delegated PC5 group information update via an in-coverage UE termed as the group lead UE.

In one example, establishing the ProSe group comprises selecting, by the respective UEs of the set thereof, respective source identifiers based on the provided group identifier and optionally, determining respective destination identifiers based on the provided group identifier.

In one example, establishing the ProSe group comprises providing group identifier information to the respective UEs of the set thereof, optionally wherein the group identifier information comprises group member identifiers and/or a group size.

In one example, the method comprises assigning, via the ProSe AS, a group lead UE from the established ProSe group.

In one example, the method comprises reassigning, via the ProSe AS, the group lead UE from the established ProSe group.

In one example, reassigning, via the ProSe AS, the group lead UE from the established ProSe group is in response to receiving, from the group lead UE, a message indicating an intention of the group lead UE to leave the established ProSe group or become out-of-coverage.

In one example, reassigning, via the ProSe AS, the group lead UE from the established ProSe group comprises updating, via the ProSe AS, the established ProSe group thereupon.

In one example, the method comprises transmitting, by an out-of-coverage UE of the established ProSe group, a message to the established ProSe group, wherein the message indicates an intention of the out-of-coverage UE to leave the established ProSe group and providing, by the group lead UE, the message to the ProSe AS, in response to receiving the transmitted message.

In one example, the method comprises updating, via the ProSe AS and/or the group lead UE, the remaining UEs of the established ProSe group.

In one example, the method comprises joining, by a new UE, the established ProSe group and optionally transmitting by the group lead UE, a message to an out-of-coverage UE of the established ProSe group, in response to joining, by the new UE, the established ProSe group.

In one example, the method comprises transmitting, by an out-of-coverage UE of the established ProSe group, a message to the established ProSe group, wherein the message comprises a coverage report.

In one example, the method comprises providing, by the group lead UE to the established ProSe group, an update to group identifier information, in response to receiving the message.

In one example, the method comprises determining a destination layer 2 identifier based on a mapping provisioned by the AS.

In one example, the method comprises amending or deleting, by the ProSe AS, ProSe parameters provisioned via a path and/or a source (e.g. 5GC) within a Unified Data Repository, UDR, such that the ProSe parameters provisioned from another path and/or another source take effect.

In a preferred embodiment of the disclosure, there is provided a method and enhanced signalling procedure for ProSe Application Server to amend or delete the policy / parameters on the UE in order to indicate the change of the path that the group identifiers (along other policy / parameters) to be provisioned.

In one example, the method comprises updating, via the ProSe AS, a path for providing a group identifier to the set of UEs.

In one example, the the ProSe AS is integrated with a 5G Direct Discovery Name Management Function, 5G DDNMF.

The second aspect provides a network comprising a set of user equipment, UEs, wherein the network is configured to:

groupcast, by the set of UEs, to the established ProSe group; and

The network, the set of UEs, the establishing, the ProSe group, the groupcasting, the established ProSe group, the groupcasting, the managing, the ProSe AL and/or the ProSe AS may be as described with respect to the first aspect.

The network may be configured to implement any method step as described with respect to the first aspect.

In one example, the network comprises and/or is a 5G network.

In the present disclosure, an access network (AN) may provide a channel for wireless communication with a UE. AN may mean a radio access network (RAN), a base station, an eNB, an eNodeB, a 5G node, a transmission/reception point (TRP, transmission/reception point), or a 5th generation NodeB (gNB). Also, in the present disclosure, a core network (CN) may manage at least one of subscriber information of the UE, mobility, access authorization, and data packet traffic (traffic), or a charging policy. The CN comprises at least one of access and mobility management function (AMF) managing network access and mobility of the UE, session management function (SMF) managing session of the UE, user plane function (UPF) transferring user data and controlled by the SMF, unified data repository (UDR), and/or policy control function (PCF) managing operator policies. The UDR may store subscription information of the UE. Functions and operations of the entities included in the core network CN may refer to a standard defined by 3GPP (TS 23.501 etc.). (5G) Direct Discovery Name Management Function (DDNMF) is a NF of the logical function handling network related actions required for dynamic ProSe Direct Discovery.

The Figures show various network functions/entities, whose functions and definitions are known in the art in at least: 3GPP TS　23.287, TS 23.303, and TS 29.555:

User Equipment: UE

ProSe Application Server: AS

Direct Discovery Name Management Function: DDNMF

(Radio) Access Network: (R)AN

Access and Mobility Management Function: AMF

Policy Control Function: PCF

Unified Data Repository: UDR

It should be understood that the functions of these network functions/entities are adapted according to the method of the first aspect and/or the network according to the second aspect.

It should be understood that the respective steps described with respect to Figures 1 to 5 may be combined, in any combination, except where the respective steps are mutually exclusive.

Figure 1 shows a first scenario according to an exemplary embodiment. This scenario indicates that group management is carried out at application layer in coordination with AS and/or 5G DDNMF.

The method is of managing a network comprising a set of user equipment, UEs, the method comprising:

groupcasting, by the set of UEs, to the established ProSe group; and

The AS may also assign a group lead within the coverage. The AS may use different criteria e.g. the location of UE, assistance information from 5G DDNMF or other 5G NFs to select the group lead. This can also be implementation specific. The assignment can be shifted on-demand to another UE, e.g. based on some application-layer signalling from the group lead indicating it is about to leave the group, to go out of coverage or indicating it is low on battery. The assignment may also change, e.g. due to lack of periodic keep alive messages from the group lead. Alternatively the assignment can be periodically rotated across in-coverage group members.

Referring to Figure 1, details of each step are as follows:

Step 101. Group management is carried out at application layer. On demand group identifier management (e.g. for commercial applications) to be handled by 5G DDNMF in coordination with AS (that is, AS+5G DDNF 140). AS may also assign a group lead within the coverage as outlined above. AS+5G DDNF 140 means a combo node of AS and 5G DDNF. The function of NF(network function) exemplified by the combo node may be implemented through interworking between two or more network entities. In Figure. 1, a "+" sign may indicate an NF that simultaneously supports functions of the AS and 5G DDNF. For example, if the AS and 5G DDNF are configured as the combo node, it may be expressed as the AS+5G DDNF 140.

Step 102. ProSe Application layer may provide group identifiers received in step 101 to ProSe Layer.

Step 103. Each

UE

110, 120 and 130 may run a ProSe direct group discovery that is restricted only to users sharing similar group identifiers (e.g. a group ID) based on step 102.

Step 104. Each

UE

110, 120 and 130 self-selects a source Layer-2 ID and determines (groupcast destination) Layer-2 ID based on group identifiers received in step 102 from ProSe Layer or based on configuration of the mapping between ProSe service type and (Destination) Layer-2 ID.

Step 105. ProSe Service for groupcast is established.

Figure 2 shows a second scenario according to an exemplary embodiment. In this scenario UE-1 110 is in-coverage and is assigned as group lead to assist the 5G DDNMF and/or AS (AS+5G DDNF 140) in Group Management. Out of coverage UE-3 130 plans to leave the group.

groupcasting, by the set of UEs, to the established ProSe group; and

Referring to Figure 2, details of each step are as follows:

Step 201. Group Communication is established and ongoing. UE-1 110 is assigned as the group lead for delegated group management by AS (or AS+5G DDNF 140).

Step 202. UE-3 130 plans to leave the group, e.g. exchanges some ProSe application layer signalling messages with

other UEs

110, 120 but UE-3 130 is temporarily out-of-coverage with no access to AS or 5GC.

Step 203. UE-3 130 invokes a Delegated Group Information Update over PC5. The PC5 is a reference point between ProSe-enabled UEs used for control and user plane for ProSe Direct Discovery, ProSe Direct Communication and ProSe UE-to-Network Relay.

Step 204. UE-1 110 as the group lead periodically listens for Delegated Group Information Update from other members on specific Destination layer 2 ID (mapped based on parameters already provisioned by AS+5G DDNF 140 when UE-1 110 joined the group or based on configuration of the mapping between ProSe service type and Destination Layer-2 ID). UE-1 110 as the group lead UE provides Group Information Update to the application server (AS) and/or 5G DDNMF (or AS+5G DDNF 140)(e.g. over PC1 and/or PC3) on behalf of UE-3 130. The PC1 is a reference point between a ProSe application in a UE and in a ProSe Application Server (AS). It is used to define application level signalling requirements. The PC3 is a reference point between a UE and a ProSe Function.

Step 205. AS in coordination with 5G DDNMF (AS+5G DDNF 140) may provide group identifier update to the remaining UEs incl. the group lead after the step 204. AS (or AS+5G DDNF 140) may also provide acknowledgment to UE-3 130 that it has left the group e.g. via the group lead.

NOTE 1: In step 204, the group lead 110 may or may not decode the payload of the delegated message when sharing with the application server and/or 5G DDNMF (AS+5G DDNF 140). In one variant of the disclosure, UE-1 110 may decode the payload and invoke a subsequent application-layer signalling message to the AS (or AS+5G DDNF 140). In another variant of the disclosure, UE-1 110 may simply relay the delegated message to the AS. In either variant, the decoding entity (either UE-1 110 or AS) can be equipped with an application-layer authentication mechanism to verify genuineness and integrity of the message from UE-3 130. This may include some unique signature and/or time stamp from UE-3 130.

Figure 3 shows a third scenario according to an exemplary embodiment. In this scenario, UE-4 (not shown in the figure 3) plans to join the group but UE-3 130 has temporarily moved out of coverage.

groupcasting, by the set of UEs, to the established ProSe group; and

Referring to Figure 3, details of each step are as follows:

Step 301. Group Communication is established and ongoing. UE-4 (not shown in the figure) plans to join the group.

Step 302. UE-3 130 is temporarily out-of-coverage with no access to AS or 5GC. UE-3 130 (being out-of-coverage) may groupcast some form of out of coverage report (e.g. optionally after some time window without coverage) to reach the group lead. UE-3 130 may also periodically listen for Delegated Group Information Update (i.e. exchanging application discovery messages) over PC5 on specific Destination layer 2 ID (mapped based on parameters already provisioned by 5G DDNMF and AS (AS+5G DDNF 140) when UE-3 130 joined the group or based on configuration of the mapping between ProSe service type and Destination Layer-2 ID).

Step 303. AS in coordination with 5G DDNMF (AS+5G DDNF 140) may provide group identifier update for the new UE (UE-4) joining the group (e.g. over PC1 and/or PC3). They may also indicate to the group lead to share this as Delegated Group information Update.

Step 304. UE-1 110 as the group lead UE provides Group Information Update over PC5 (e.g. based on the trigger of out of coverage report in the step 302.) to be collected by UE-3 130.

NOTE 2: In steps 303 and/or 304, UE-1 110 as the group lead may or may not know the ID(s) of UE(s) that the delegated message is intended for.

Figure 4 shows a fourth scenario according to an exemplary embodiment. In this scenario, the lead UE-1 110 plans to leave the group (or moves out of coverage). AS may assign another in-coverage UE as group lead for delegated PC5 group management or otherwise to terminate the group communication.

groupcasting, by the set of UEs, to the established ProSe group; and

Referring to Figure 4, details of each step are as follows:

Step 401. Group Communication is established and ongoing.

Step 402. UE-1 110 formerly assigned as the group lead by the AS (or AS+5G DDNF 140) may plan to leave the group, leave the group lead position (or is about to move out of coverage). This can be indicated by an application-layer signalling to the AS. Alternatively, this could be implicitly identified by the AS (e.g. due to lack of periodic keep alive messages from UE-1 over PC1). The AS may also provide acknowledgment to UE-1 110 that it has left the group or group lead position.

Step 403. UE-3 130 is assigned as the new group lead by the AS (or AS+5G DDNF 140) (e.g. over PC1).

Step 404. AS in coordination with 5G DDNMF (AS+5G DDNF 140) may provide group identifier update to remaining UEs including UE-3 130 (e.g. over PC1 and/or PC3).

NOTE 3: UE-1 110, when moves out of coverage, is aware that it will lose the group lead status so may listen for Delegated Group Information Update PC5 messages (from the new group lead) in case it plans to continue on group communication.

NOTE 4: Each member UE may listen for Delegated Group Information update over PC5 when out of coverage only as far as the validly time of delegated group identifier parameters (e.g. the mapping for specified Destination layer 2 ID already provisioned by 5G DDNMF) has not expired. After the expiry, if the UE is still not back in coverage, it may discontinue all discovery procedures for this group assuming its membership has been terminated.

NOTE 5: Each member UE may or may not be aware of the group lead assignment or ID as they listen to the specified Destination layer 2 ID based on the mapping provisioned by 5G DDNMF (or AS+5G DDNF 140) (e.g. over PC1 and/or PC3) or based on configuration of the mapping between ProSe service type and Destination Layer-2 ID.

Figure 5 shows a fifth scenario according to an exemplary embodiment. In this scenario, the AS decides to update the path for provisioning group identifiers (along other policy / parameters) from e.g. PCF to PC1/ PC3 or vice versa. However, having multiple different data paths for provisioning group identifiers may result in a conflict in the UE on what information to be adopted.

groupcasting, by the set of UEs, to the established ProSe group; and

In one sub-variant of this disclosure the UE may rely on a predefined precedence i.e. priority of one path of data provisioning over another. For example, parameters provided by Application server can be given priority over the ones provided by PCF or vice versa. However, this scheme may not always work due to a fixed priority if the AS decides to change the priority and the path based on the defined criteria (e.g. based on the level of load on each interface).

In another sub-variant of the disclosure, the UE may treat parameters provided from different paths (i.e. PC1, PC3 or PCF) equivalently. However, the priority can be given to parameters with e.g. longer validity timer.

In another sub-variant of the disclosure, the UE may be given an indication as part of policy /parameters provisioning for the group discovery/ communication on the current precedence of one data source and/or path over another. Such indication can be static, semi-static or dynamically changed by PCF.

In another sub-variant of the disclosure, the AS may amend or delete the Application Data within the UDR, relevant to the group identifiers (along other policy / parameters) such that PCF can update, delete or nullify the parameters already given through its path. This enables provisioning of new parameters from an alternative path (e.g. PC1 or PC3) or other sources (e.g. pre-configured parameters in the UEs in Universal Integrated Circuit Card (UICC) or Mobile Equipment (ME)).

Referring to Figure 5, details of each step are as follows:

Step 501. The AS 560 decides to update the parameters provisioning path (e.g. from PCF to PC1). The AS 560 provides a Service Parameter Update to amend the associated parameters (e.g. group identifiers) from the PCF-based provisioning. The amendment could be for example to shorten the validity time or to lower the precedence of PCF path based on different sub-variants of this disclosure as described before. Alternatively, the AS 560 may request to delete such parameters from UDR 550 based on another sub-variant of this disclosure described before.

Step 502. Based on data change in UDR 550 in the step 501, the UDR 550 may notify PCF 540 through Nudr_DM_Notify (referred in 3GPP TS 23.501) for notification of data change from the UDR 550. Here, it is assumed that PCF 540 has already subscribed to UDR 550 to be notified on Application Data changes.

Step 503. PCF 540 amends or deletes associated policy/ parameters (e.g. group identifiers).

Step 504. PCF 540 provisions updated parameters to the UE 510 via UE configuration Update Procedure in 3GPP standard.

Step 505. Based on the updated policy/ parameters, UE 510 prioritises parameters provided from other sources or paths (e.g. PC1 path or what pre-configured in UICC or ME).

NOTE 6: In

steps

501, 502, PCF 540 can additionally be notified on the new parameters to be shared via other path (e.g. PC1). However, a new indication parameter or service type may request from the PCF 540 to only authorise or withhold such information but not to update the UE 510 (over UE Configuration Update) to avoid conflict in the UE 510.

Although presented in terms of ProSe and 5GC, the skilled person will readily appreciate that other network topologies and/or protocols which rely on group communication between UEs will benefit from embodiments of the disclosure.

Although a preferred embodiment has been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the disclosure, as defined in the appended claims and as described above.

Figure 6. shows a block diagram of a UE performing operations according to an embodiment.

Referring to Figure. 6, the UE may include a processor 610 and a transceiver 620. In a communication system described above in connection with Figures. 1 to 5, according to the disclosure, the UE may be operated in the manners described above in connection with Figures. 1 to 5. However, the components of the UE are not limited thereto. According to an embodiment, the UE may include more components than those described above or, the UE may include fewer components. According to an embodiment, the processor 610 and the transceiver 620 may be implemented in the form of a single chip.

According to an embodiment, the transceiver 620 may include a transmitter and a receiver. The transceiver 620 may transmit and receive signals to/from (R)AN(a base station, etc.) or other UE(s). The signals may include at least one of control information and data. To that end, the transceiver 620 may include a radio frequency (RF) transmitter for frequency-up converting and amplifying signals transmitted and an RF receiver for low-noise amplifying signals received and frequency-down converting the frequency of the received signals. The transceiver 620 may receive signals via a radio channel, output the signals to the processor 610, and transmit signals output from the processor 610 via a radio channel.

The processor 610 may control operations to allow the UE to operate according to one or a combination of the above-described embodiments.

Figure 7. shows a block diagram of a network entity performing operations according to an embodiment. The network entity may be one of the above AS, DDNMF, AS + DDNMF, UDR, PCF, AMF and RAN.

Referring to Figure. 7, the network entity may include a processor 710 and a transceiver 720. In a communication system described above in connection with Figures. 1 to 5, according to the disclosure, the network entity may be operated in the manners described above in connection with Figures. 1 to 5. However, the components of the network entity are not limited thereto. According to an embodiment, the network entity may include more components than those described above or, the network entity may include fewer components. According to an embodiment, the processor 710 and the transceiver 720 may be implemented in the form of a single chip or a server.

According to an embodiment, the transceiver 720 may include a transmitter and a receiver, or include a communication interface communicating with other network entity via wired or wireless communication. The processor 710 may control operations to allow the network entity to operate according to one or a combination of the above-described embodiments.

At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as 'component', 'module' or 'unit' used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term "comprising" or "comprises" means including the component(s) specified but not to the exclusion of the presence of others.

Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The disclosure is not restricted to the details of the foregoing embodiment(s). The disclosure extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

A method of managing a network comprising a set of user equipment, UEs, the method comprising:

establishing, by the set of UEs, a Proximity Services, ProSe, group comprising the set of UEs;

groupcasting, by the set of UEs, to the established ProSe group; and

managing, by the set of UEs, the established ProSe group at a ProSe application layer, AL, optionally in coordination with a ProSe Application Server, AS.
The method of claim 1, wherein establishing the ProSe group comprises providing, by the ProSe AL, a group identifier to the set of UEs.
The method of claim 2, wherein establishing the ProSe group comprises performing, by the respective UEs of the set thereof, group discovery using the provided group identifier by exchanging application discovery messages, optionally wherein establishing the ProSe group is restricted to UEs of the set thereof having the same group identifier provided thereto.
The method of claim 3, wherein exchanging the application discovery messages comprises exchanging the application discovery messages over a PC5 reference point between the UEs of the set thereof.
The method of any one of claims 2 to 4, wherein establishing the ProSe group comprises selecting, by the respective UEs of the set thereof, respective source identifiers based on the provided group identifier and optionally, determining respective destination identifiers based on the provided group identifier.
The method of any one of claims 2 to 5, wherein establishing the ProSe group comprises providing group identifier information to the respective UEs of the set thereof, optionally wherein the group identifier information comprises group member identifiers and/or a group size.
The method of claim 1, comprising assigning, via the ProSe AS, a group lead UE from the established ProSe group.
The method of claim 7, comprising reassigning, via the ProSe AS, the group lead UE from the established ProSe group.
The method of claim 8, wherein reassigning, via the ProSe AS, the group lead UE from the established ProSe group is in response to receiving, from the group lead UE, a message indicating an intention of the group lead UE to leave the established ProSe group or become out-of-coverage.
The method of any one of claims 8 to 9, wherein reassigning, via the ProSe AS, the group lead UE from the established ProSe group comprises updating, via the ProSe AS, the established ProSe group thereupon.
The method of any one of claims 7 to 10, comprising transmitting, by an out-of-coverage UE of the established ProSe group, a message to the established ProSe group, wherein the message indicates an intention of the out-of-coverage UE to leave the established ProSe group and providing, by the group lead UE, the message to the ProSe AS, in response to receiving the transmitted message.
The method of claim 11, comprising updating, via the ProSe AS and/or the group lead UE, the remaining UEs of the established ProSe group.
The method of any one of claims 7 to 12, comprising joining, by a new UE, the established ProSe group and optionally transmitting by the group lead UE, a message to an out-of-coverage UE of the established ProSe group, in response to joining, by the new UE, the established ProSe group.
A network comprising a set of user equipment, UEs, wherein the network is configured to:

establish, by the set of UEs, a Proximity Services, ProSe, group comprising the set of UEs;

groupcast, by the set of UEs, to the established ProSe group; and

manage, by the set of UEs, the established ProSe group at a ProSe application layer, AL, optionally in coordination with a ProSe Application Server, AS.
A network of claim 14 adapted to operate according to any one of claims 2 to 13.