Patent Description:
The <NUM>th generation wireless communication technology (<NUM>) is based on a so-called network slicing concept as schematically illustrated in <FIG>. A network slicing refers to an implementation in which a physical infrastructure of a telecommunication network <NUM> is shared between service providers <NUM> executing virtual logical networks created on a top of the physical infrastructure. In that manner it is possible to establish an independent set of logical network functions for each virtual network to dedicate the network slice in question to different application areas <NUM>. This kind of conceptual thinking allows to define network performance parameters and functions optimal to each use case. As regards to the non-limiting example of <FIG> it may be arranged that a first slice (SLICE <NUM>) is dedicated to providing multimedia services as application area <NUM> and, thus, serving clients requiring services in that area. For example, a requirement for a communication service, and, thus, to the corresponding slice, may e.g. be a broadband communication. On the other hand, a second slice (SLICE <NUM>) may relate to so-called loT communication which means that a significant amount of resources of a mobile communication network <NUM> resources shall be allocated to this slice, since an amount of communication may be huge. Still further, in a third slice (SLICE <NUM>) an essential feature is that a latency in the communication is low, which may e.g. relate to a communication of connected vehicles, and for that reason the slice in question may be harnessed to provide low latency communication service. In at least some embodiment, one slice (SLICE <NUM>) may be reserved for other service types. In the described manner, resources of the mobile communication network <NUM> may be optimally directed according to the service needs and, in that manner, allowing the service providers, such as virtual network operators, to serve the subscribers in a better way. As said, an example of a communication system implementing the slicing concept is so-called <NUM> communication network system.

In a document <CIT> it is disclosed a solution for registering a user terminal in a wireless communication system.

In view of above, there is need to develop mechanisms and solutions for setting up a communication connection in the sliced communication network environment.

It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention, which is solely defined by the appended claims.

The following summary merely presents some concepts in a simplified form as a prelude to a more detailed description of exemplifying embodiments.

An object of the invention is to present a method, according to claim <NUM>, a network node, according to claim <NUM>, a communication system according to claim <NUM>, and a computer program product, according to claim <NUM>, for setting up a communication session to a terminal device.

The objects of the invention are reached by a method, a network node, a communication system and a computer program product as defined by the respective independent claims.

According to a first aspect, a method for setting up a communication session to a terminal device is provided, the method, performed by an Access and Mobility Function, AMF, comprises: receiving a registration request from the terminal device, the registration request comprising data indicating a unique transaction identifier for the terminal device, the unique transaction identifier for the terminal device being a non-IMSI based user identifier having a form [ID]. username@realm, wherein a portion denoted with [ID] comprises a determination of a service provider followed by a determination of a task defined to a subscription; interacting communicatively with a Network Slice Selection Function, NSSF, for assigning on a basis of the unique transaction identifier a network slice of a mobile communication network providing communication service to the terminal device, the network slice being accessible with a session management function initiated for the terminal device; interacting communicatively with a Policy Control Function, PCT, for assigning a charging and policy scheme to be applied to the terminal device, the charging and policy scheme being accessible with an application function initiated for the terminal device; in response to the assigning of the network slice and the assigning of the charging and policy scheme for the communication session generating an acknowledgement to the terminal device, the acknowledgement indicating an acceptance to the registration request for causing a setup of the communication session by the terminal device between the terminal device and the application function through a user plane function.

According to a second aspect, an Access and Mobility Function, AMF, is provided, the network node comprising: at least one processor; at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the Access and Mobility Function, AMF, to perform: receive a registration request from a terminal device, the registration request comprising data indicating a unique transaction identifier for the terminal device, the unique transaction identifier for the terminal device being a non-IMSI based user identifier having a form [ID]. username@realm, wherein a portion denoted with [ID] comprises a determination of a service provider followed by a determination of a task defined to a subscription; interact communicatively with a Network Slice Selection Function, NSSF, for assigning, on a basis of the unique transaction identifier, a network slice of a mobile communication network providing communication service to the terminal device, the network slice being accessible with a session management function initiated for the terminal device; interact communicatively with a Policy Control Function, PCF, for assigning a charging and policy scheme to be applied to the terminal device determined on a basis of the unique transaction identifier, the charging and policy scheme being accessible with an application function initiated for the terminal device; in response to the assigning of the network slice and the assigning of the charging and policy scheme for the communication session generate an acknowledgement to the terminal device, the acknowledgement indicating an acceptance to the registration request for causing a setup of the communication session by the terminal device between the terminal device and the application function through a user plane function.

According to a third aspect, a communication system is provided, the communication system comprising an Access and Mobility Function, AMF, according to the second aspect defined in the foregoing description.

According to a fourth aspect, a computer program product for setting up a communication session is provided which computer program product, when executed by at least one processor, cause an Access and Mobility Function, AMF, to perform the method according to the first aspect defined in the foregoing description.

Various exemplifying and non-limiting embodiments both as to constructions and to methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying and non-limiting embodiments when read in connection with the accompanying drawings.

In order to describe at least some aspects according to an embodiment of the a referral is made to <FIG> illustrates schematically at least some entities in a core network <NUM> and in a radio access network <NUM> of a <NUM> network arranged to serve a terminal device <NUM>. For a purpose of describing at least some aspects of the present disclosure the core network <NUM> comprises at least the following entities/functions:.

As is derivable from above a <NUM> architecture is definable as a functional architecture wherein functions are executed by an applicable physical device or devices. Still further, interfaces between the mentioned functions, and other functions not disclosed in <FIG>, are defined and implemented as indicated in <FIG>.

Still further, the radio access network <NUM> of <NUM> communication network comprises one or more Next Generation Node B (gNB) <NUM> supporting at least so-called <NUM> NR (New Radio) air interface for communicating with terminal devices <NUM>.

<FIG> illustrates schematically an example of a method for setting up a communication session to a terminal device <NUM> according to an embodiment.

In order to initiate a setup of the communication session the terminal device <NUM> may be arranged to generate a registration request e.g. in response to a user interaction with the terminal device <NUM> or automatically e.g. in response to a detection that one or more predetermined conditions are fulfilled. The generation of the registration request may comprise, but is not limited to, an insertion of a unique transaction identifier representing the terminal device <NUM>, or the user, in the registration request. The unique transaction identifier is established by manipulating a typically used non-IMSI (International Mobile Subscription Identifier) based user identifier so that it also comprises an identifier of a transaction relating to the communication session to be established. Such an identifier of the transaction may represent a mission to be accomplished with the communication session, or any particulars being relevant in the communication session to be established. An example useful for understanding the present invention is that the identifier of the transaction may indicate a group the user belongs to, which may be used for reporting, billing and prioritization purposes if desired. In other words, in accordance with the present invention the typically used non-IMSI based user identifier username@realm is modified to a form [ID]. username@realm (e.g. wherein the [ID] portion may be expressed in a form of ABC-running_number, wherein the ABC determines the service provider in question and the running_number a task defined to the subscription). In any case, the portion representing the identifier of the transaction provides further information to be used for setting up the communication session as will be described in the forthcoming description. As mentioned, the terminal device <NUM> generates the registration request with the data as indicated and transmits it towards the core network <NUM>, and specifically to the Access and Mobility Management Function AMF <NUM>, over the radio access network <NUM>. In other words, the AMF <NUM> receives <NUM> the registration request from the terminal device <NUM>. In some embodiments the registration request may correspond to so-called attach request message.

For sake of clarity it is worthwhile to mention that the identifier of the transaction represented e.g. with the [ID] portion in the above described user identifiers may be used for identifying a purpose of use and/or targeting actions in the communication network (e.g. beamforming, slicing, enabling Multi-access Edge Computing (MEC) service, Local Break Out (LBO) service, and so on). Moreover, it is worthwhile to mention that a computing platform applied to a management of a number of subscriptions, such as dedicated to machine-to-machine communication, may be formed so as to serve the above described group-based approach. This may be achieved by arranging a data field in a context of subscription identifiers, such as MSISDN numbers, defining a group a subscription in question belongs to. Data defined in such a field may then be used e.g. for allocating tasks to subscribers belonging to a certain group.

In response to a receipt <NUM> of the registration request from the terminal device <NUM> over the communication network the AMF <NUM> is arranged to determine the unique transaction identifier from the registration request and to determine a network slice from a plurality of network slices arranged for different purposes as discussed in a context of <FIG>. Naturally, prior to taking any steps in this regard the AMF <NUM> may perform authentication of the user through a communication with the UDM/UDR <NUM>, wherein the authentication is performed by checking information carried in the unique transaction identifier from the UDM/UDR <NUM>. If the authentication is performed and is confirmed, the determination of the network slice may be performed. Moreover, if no authentication procedure is applied to, the process continues directly by determining the network slice, as will be described. The determination of the network slice may be performed on a basis of the unique transaction identifier by requesting, by the AMF <NUM> from the NSSF <NUM>, a selection of the network slice by generating so-called Slice Selection Request message to NSSF <NUM>. The request may comprise the unique transaction identifier, or at least relevant parts of it, for selecting the applicable network slice. The NSSF <NUM> may detect at least some details relating to the requested communication session, such as the mission of the communication session on the basis of the unique transaction identifier, and is arranged to match an applicable network slice suitable to provide communication service required to accomplish the mission. As a non-limiting example, the communication session may be established to serving a drone. The unique transaction identifier may indicate e.g. a service provider of the drone and a mission to be accomplished with the drone. Based on this, the suitable slice may be determined which is hosted by a network service provider providing services to a certain customer segment, such as to service provider of the drone. More specifically, the NSSF <NUM> may be arranged to determine a suitable network slice, and hence a suitable AMF, by generating a query to a Network Function Repository Function (NRF) supporting a service discover function. As a result, the NSSF <NUM> provides so-called NSI (Network Slice Instance) identifier(s), allowed S-NSSAI(s) (Single - Network Slice Selection Assistance Information) and AMF candidate(s) to the AMF <NUM> which initiated the inquiry. Hence, as a result of the determination of the network slice on the basis of the unique transaction identifier, the determined network slice may be assigned <NUM> to the terminal device <NUM> which allows a Session Management Function SMF <NUM> initiated by the AMF <NUM> in response to a receipt of the registration request from the terminal device <NUM> to access to the assigned network slice i.e. at least to control a utilization of the communication resources reserved for the network slice. In this regard, the AMF <NUM> may send a registration accept message including allowed S-NSSAI(s) to the terminal device <NUM>.

Moreover, in response to a receipt of the registration request with the unique transaction identifier a determination of a charging and policy scheme to be applied to the terminal device <NUM> in the communication session is performed. The charging and policy scheme may be determined by arranging the AMF <NUM> to inquire it from the Policy Control Function PCF <NUM> the unique transaction identifier as a parameter in the inquiry. Since the service provider in question has created an agreement, i.e. service level agreement defining the charging and policy scheme, with a telecom operator providing the network and, hence, the network slices, the PCF <NUM> may generate data, based on information obtainable from data storage on the basis of the parameter, indicating the charging and policy scheme to be applied to, and returns the data to the AMF <NUM> causing an assignment <NUM> of the charging and policy scheme to the terminal device <NUM> in question. The charging and policy scheme to be applied is accessible with the application function initiated in the network side for the terminal device <NUM> in question in order to generate session related information to a PCRF (Policy and Charging Rules Function).

For sake of clarity it is worthwhile to mention that the steps of assigning the network slice <NUM> and the step of assigning the charging and policy scheme <NUM> may be performed consecutively to each other, as shown in <FIG>, or concurrently at least in part.

In response to the assignment of the network slice <NUM> and the assignment of the charging and policy scheme <NUM> for the communication session the AMF <NUM> may be arranged to generate <NUM> an acknowledgement to the terminal device <NUM>. The acknowledgement may at least indicate an acceptance of the registration request causing a setup of the communication session between the terminal device <NUM> and a user plane function <NUM>. Hence, the terminal device <NUM> may communicate with an entity, such as with the application function, AF, <NUM>, residing in the data network <NUM> over the communication session. For example, the entity may provide service to the terminal device <NUM> for accomplishing the mission, or task, over the selected network slice.

<FIG> illustrates schematically an example of the method according to an embodiment as a flow chart. In <FIG> signals being relevant to understand the present disclosure are disclosed. The signal <NUM> in <FIG> represents a registration request transmitted from the terminal device <NUM> to the AMF <NUM>. In response to a receipt <NUM> of the signal <NUM> the AMF <NUM> is arranged to generate a signal towards NSSF <NUM> for achieving an assignment <NUM> of a network slice to the terminal device <NUM>. In order to reach the assignment of the network slice <NUM> the unique transaction identifier is used as a parameter for determining an applicable slice. Signal <NUM> in <FIG> represents an interaction between the mentioned entities for reaching the assignment of the network slice. Correspondingly, in response to a receipt <NUM> of the signal <NUM> the AMF <NUM> may also be arranged to generate a signal towards PCF <NUM> as described for achieving an assignment <NUM> of a charging and policy scheme to the terminal device <NUM> to be applied in the communication session over the network slice. In order to reach the assignment <NUM> of the charging and policy scheme the unique transaction identifier is used as a parameter for determining the charging and policy scheme to be applied to the terminal device <NUM> as described in the foregoing description. Signal <NUM> in <FIG> represents an interaction between the mentioned entities for reaching the assignment <NUM> of the charging and policy scheme. In response to the successful assignments <NUM>, <NUM> the AMF <NUM> generates <NUM> the acknowledgement <NUM> to the terminal device <NUM>. The acknowledgement <NUM> may comprise data indicating the network slice to be used in the communication session as well as data representing aspects relating to the charging and policy scheme to be applied. For example, the pieces of data may comprise information on suitable, or selected, SMF <NUM> and UPF <NUM>. In response to a receipt of the pieces of data the terminal device <NUM> may establish <NUM> the communication session over the selected UPF <NUM> which is arranged to forward the data traffic to the application function, AF, <NUM> by the UPF <NUM> over the data network <NUM>.

As discussed above, a network node arranged to perform functionalities of an Access and Mobility Management Function, AMF, may perform at least some steps of the method as described. <FIG> illustrates schematically as a block diagram a non-limiting example of the network node applicable to perform the method. The block diagram of <FIG> depicts some components of an apparatus that may be employed to implement an operation of the network node. The apparatus comprises a processor <NUM> and a memory <NUM>. The memory <NUM> may store data and computer program code <NUM>. The apparatus may further comprise communication means <NUM> for wired and/or wireless communication with other apparatuses, such as other network nodes implementing the functionalities as described. Furthermore, I/O (input/output) components <NUM> may be arranged, together with the processor <NUM> and a portion of the computer program code <NUM>, to provide a user interface for receiving input from a user and/or providing output to the user. In particular, the user I/O components may include user input means, such as one or more keys or buttons, a keyboard, a touchscreen or a touchpad, etc. The user I/O components may include output means, such as a display or a touchscreen. The components of the apparatus may be communicatively coupled to each other via a bus <NUM> that enables transfer of data and control information between the components.

The memory <NUM> and a portion of the computer program code <NUM> stored therein may be further arranged, with the processor <NUM>, to cause the apparatus, i.e. the network node to perform a method as described in the foregoing description.

The processor <NUM> may be configured to read from and write to the memory <NUM>. Although the processor <NUM> is depicted as a respective single component, it may be implemented as respective one or more separate processing components. Similarly, although the memory <NUM> is depicted as a respective single component, it may be implemented as respective one or more separate components, some or all of which may be integrated/removable and/or may provide permanent / semi-permanent / dynamic / cached storage.

The computer program code <NUM> may comprise computer-executable instructions that implement functions that correspond to steps of the method as will be described when loaded into the processor <NUM>. As an example, the computer program code <NUM> may include a computer program consisting of one or more sequences of one or more instructions. The processor <NUM> is able to load and execute the computer program by reading the one or more sequences of one or more instructions included therein from the memory <NUM>. The one or more sequences of one or more instructions may be configured to, when executed by the processor <NUM>, cause the apparatus to perform the method be described. Hence, the apparatus may comprise at least one processor <NUM> and at least one memory <NUM> including the computer program code <NUM> for one or more programs, the at least one memory <NUM> and the computer program code <NUM> configured to, with the at least one processor <NUM>, cause the apparatus to perform the method as described.

The computer program code <NUM> may be provided e.g. a computer program product comprising at least one computer-readable non-transitory medium having the computer program code <NUM> stored thereon, which computer program code <NUM>, when executed by the processor <NUM> causes the apparatus to perform the method. The computer-readable non-transitory medium may comprise a memory device or a record medium such as a CD-ROM, a DVD, a Blu-ray disc or another article of manufacture that tangibly embodies the computer program. As another example, the computer program may be provided as a signal configured to reliably transfer the computer program.

Still further, the computer program code <NUM> may comprise a proprietary application, such as computer program code for executing the setup of the communication session in the manner as described.

Any of the programmed functions mentioned may also be performed in firmware or hardware adapted to or programmed to perform the necessary tasks.

Some aspects of the present disclosure relate to a communication system comprising a network node implementing the method as described.

Claim 1:
A method for setting up a communication session to a terminal device (<NUM>), the method, performed by an Access and Mobility Function, AMF, (<NUM>) comprises:
receiving (<NUM>) a registration request from the terminal device (<NUM>), the registration request comprising data indicating a unique transaction identifier for the terminal device (<NUM>), the unique transaction identifier for the terminal device (<NUM>) being a non-IMSI based user identifier having a form [ID].username@realm, wherein a portion denoted with [ID] comprises a determination of a service provider followed by a determination of a task defined to a subscription ,
interacting (<NUM>) communicatively with a Network Slice Selection Function, NSSF, (<NUM>) for assigning (<NUM>), on a basis of the unique transaction identifier, a network slice of a mobile communication network providing communication service to the terminal device (<NUM>), the network slice being accessible with a session management function initiated for the terminal device (<NUM>),
interacting (<NUM>) communicatively with a Policy Control Function, PCF, (<NUM>) for assigning (<NUM>) a charging and policy scheme to be applied to the terminal device (<NUM>) determined on a basis of the unique transaction identifier, the charging and policy scheme being accessible with an application function initiated for the terminal device,
in response to the assigning (<NUM>) of the network slice and the assigning (<NUM>) of the charging and policy scheme for the communication session generating (<NUM>) an acknowledgement to the terminal device (<NUM>), the acknowledgement indicating an acceptance to the registration request for causing a setup of the communication session by the terminal device (<NUM>) between the terminal device and the application function through a user plane function.