DESCRIPTION

BACKGROUND

Field

The present invention relates to apparatuses, methods, systems, computer programs, computer program products and computer-readable media usable for conducting a communication connection control procedure using selected network slices or communication connection slices, an in particular to a communication connection control procedure where a user plane function conducted a radio slice selection.

Background Art

The following description of background art may include insights, discoveries, understandings or disclosures, or associations, together with disclosures not known to the relevant prior art, to at least some examples of embodiments of the present invention but provided by the invention. Some of such contributions of the invention may be specifically pointed out below, whereas other of such contributions of the invention will be apparent from the related context.

The following meanings for the abbreviations used in this specification apply:

3GPP 3 ^rd Generation Partner Project

5G fifth generation

AF application function

AMF access and mobility function

AN access network

AUSF authentication server function

BS base station

CN core network

CP control plane

CPU central processing unit DL downlink

DN data network

DPI deep packet inspection

eNB evolved node B

EPC evolved packet core

ETSI European Telecommunications Standards Institute

IE information element

IP Internet protocol

LDN local data network

LTE Long Term Evolution

LTE-A LTE Advanced

MEC mobile edge computing

NR new radio

PCF policy control function

PDU packet data unit

QoS quality of service

RAN radio access network

RAT radio access technology

SMF session and mobility management function

TFT traffic flow template

UDM user data management

UE user equipment

UL uplink

UP user plane

UPF user plane function

UMTS universal mobile telecommunication system

VoIP voice over IP

SUMMARY

According to an example of an embodiment, there is provided, for example, an apparatus for use by a core network control element or function configured to execute a communication connection related control, the apparatus comprising at least one processing circuitry, and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the apparatus at least: to generate an information element including information related to at least one communication connection slice selectable for a downlink packet transmission towards a communication element or function, and to cause transmission of the information element to a network control element or function configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission.

Furthermore, according to an example of an embodiment, there is provided, for example, a method for use in a core network control element or function configured to execute a communication connection related control, the method comprising generating an information element including information related to at least one communication connection slice selectable for a downlink packet transmission towards a communication element or function, and causing transmission of the information element to a network control element or function configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission.

According to further refinements, these examples may include one or more of the following features:

- data used for generating the information element may be obtained from at least one of a core network control element or function configured for session management, a core network control element or function configured for user data management, and a core network control element or function configured for policy control;

- the information element may include information indicating which of a plurality of communication connection slices is allowed to be selected for a specific session in which the downlink packet transmission is executed, and information indicating a transmission characteristic of the at least one communication connection slice;

- the information element may further indicate whether the at least one communication connection slice has a guaranteed bandwidth;

- the information element may further indicate all available communication connection slices irrespective of whether or not they are allowed to be selected for the specific session;

- the information element may further indicate information enabling a mapping between a content of the information element and quality of service requirements for the downlink packet transmission for creating a mapping between a traffic type of the communication connection and the selected communication connection slice;

- the transmission of the information element to the network control element or function configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission may be caused in a session establishment procedure or in a session update procedure; - the transmission of the information element to the network control element or function configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission may be caused by using a downlink transport level marking signaling transmitted via an interface between a control plane network control element or function and a user plane network control element or function, wherein the information element may be included in the downlink transport level marking signaling in place of a type of service indication or a traffic class indication;

- the transmission of the information element to the network control element or function configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission may be caused by using a dedicated signaling transmitted via an interface between a control plane network control element or function and a user plane network control element or function;

- in case to there is a plurality of network control elements or functions configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission, it may be decided which of the plurality of network control elements or functions is allowed to conduct the traffic steering processing, and an indication may be sent to the plurality of network control elements or function for informing about the decision;

- the apparatus or method may be implemented in control plane core network control element orfunction, the network control element or function configured to conduct the traffic steering processing may be included in a user plane core network control element or function or in a mobile edge computing network control element or function, the communication connection slice for the downlink packet transmission may include a radio slice, and the information element may be transmitted via an interface between a control plane core network control element or function and a user plane core network control element or function.

In addition, according to an example of an embodiment, there is provided, for example, an apparatus for use by a network control element or function configured to conduct a traffic steering processing in a communication connection, the apparatus comprising at least one processing circuitry, and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured to, with the at least one processing circuitry, cause the apparatus at least: to receive and process an information element including information related to at least one communication connection slice selectable for a downlink packet transmission towards a communication element or function, and to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission on the basis of the received information element.

Furthermore, according to an example of an embodiment, there is provided, for example, a method for use in a network control element or function configured to conduct a traffic steering processing in a communication connection, the method comprising receiving and processing an information element including information related to at least one communication connection slice selectable for a downlink packet transmission towards a communication element or function, and conducting a traffic steering processing for selecting a communication connection slice for a downlink packet transmission on the basis of the received information element.

According to further refinements, these examples may include one or more of the following features:

- for conducting the traffic steering processing, a packet inspection may be executed for determining a quality of service requested for a packet to be transmitted in downlink direction, and a communication connection slice for the downlink packet transmission may be selected by considering the requested quality of service and the information obtained from the information element;

- the information element may include information indicating which of a plurality of communication connection slices is allowed to be selected for a specific session in which the downlink packet transmission is executed, and information indicating a transmission characteristic of the at least one communication connection slice;

- the information element may further indicate whether the at least one communication connection slice has a guaranteed bandwidth;

- the information element may further indicate all available communication connection slices irrespective of whether or not they are allowed to be selected for the specific session;

- the information element further may indicate information enabling a mapping between a content of the information element and quality of service requirements for the downlink packet transmission for creating a mapping between a traffic type of the communication connection and the selected communication network slice;

- the information element may be received and processed in a session establishment procedure or in a session update procedure;

- the information element may be received by a downlink transport level marking signaling transmitted via an interface between a control plane network control element or function and a user plane network control element or function, wherein the information element may be included in the downlink transport level marking signaling in place of a type of service indication or a traffic class indication;

- the information element may be received by a dedicated signaling transmitted via an interface between a control plane network control element or function and a user plane network control element or function;

- an indication regarding an allowance to conduct the traffic steering processing may be received and processed in case there is a plurality of network control elements or functions configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission, and the traffic steering processing may be conducted in case the allowance is received, or the traffic steering processing may be stopped in case the allowance is not received;

- the apparatus and method may be implemented in a user plane core network control element or function or in a mobile edge computing network control element or function, the information element may be received from a core network control element or function configured to execute a communication connection related control in control plane core network control element or function, the communication connection slice for the downlink packet transmission may include a radio slice, and the information element may be transmitted via an interface between a control plane core network control element or function and a user plane core network control element or function.

In addition, according to embodiments, there is provided, for example, a computer program product for a computer, including software code portions for performing the steps of the above defined methods, when said product is run on the computer. The computer program product may include a computer-readable medium on which said software code portions are stored. Furthermore, the computer program product may be directly loadable into the internal memory of the computer and/or transmittable via a network by means of at least one of upload, download and push procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

Some embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 shows a diagram illustrating a communication network configuration in which examples of embodiments of the invention are implementable; Fig. 2 shows a diagram illustrating an information element structure according to some examples of embodiments;

Fig. 3 shows a flow chart of a communication connection control procedure according to some examples of embodiments;

Fig. 4 shows a flow chart of a communication connection control procedure according to some examples of embodiments;

Fig. 5 shows a diagram of a network element or function acting as a core network control element for conducting a communication connection control procedure according to some examples of embodiments; and

Fig. 6 shows a diagram of a network element or function acting as a core network control element for conducting a communication connection control procedure according to some examples of embodiment.

DESCRIPTION OF EMBODIMENTS

In the last years, an increasing extension of communication networks, e.g. of wire based communication networks, such as the Integrated Services Digital Network (ISDN), DSL, or wireless communication networks, such as the cdma2000 (code division multiple access) system, cellular 3 ^rd generation (3G) like the Universal Mobile Telecommunications System (UMTS), fourth generation (4G) communication networks or enhanced communication networks based e.g. on LTE or LTE-A, fifth generation (5G) communication networks, cellular 2 ^nd generation (2G) communication networks like the Global System for Mobile communications (GSM), the General Packet Radio System (GPRS), the Enhanced Data Rates for Global Evolution (EDGE), or other wireless communication system, such as the Wireless Local Area Network (WLAN), Bluetooth or Worldwide Interoperability for Microwave Access (WiMAX), took place all over the world. Various organizations, such as the European Telecommunications Standards Institute (ETSI), the 3 ^rd Generation Partnership Project (3GPP), Telecoms & Internet converged Services & Protocols for Advanced Networks (TISPAN), the International Telecommunication Union (ITU), 3 ^rd Generation Partnership Project 2 (3GPP2), Internet Engineering Task Force (IETF), the IEEE (Institute of Electrical and Electronics Engineers), the WiMAX Forum and the like are working on standards or specifications for telecommunication network and access environments. Generally, for properly establishing and handling a communication between two or more end points (e.g. communication stations or elements, such as terminal devices, user equipments (UEs), or other communication network elements, a database, a server, host etc.), one or more network elements such as communication network control elements, for example access network elements like access points, radio base stations, relay stations, eNBs, gNBs etc., and core network elements or functions, for example control nodes, support nodes, service nodes, gateways etc., may be involved, which may belong to one communication network system or different communication network systems.

Next-generation (also referred to as 5G) networks will provide significant improvements for achieving a fully mobile and connected society. A variety of new use cases and business models is under discussion as being available for customers. However, for providing sufficient capabilities in the communication networks to allow this, it is necessary to rethink the structure of communication networks and in particular mobile networks to support very diverse and extreme requirements for e.g. latency, throughput, capacity, and availability.

Traditionally, telecommunication networks mainly target mobile phone like devices (e.g. smartphones, tablets, etc.). However, in future network architectures, such as 5G networks, the mobile network needs to serve a wide variety of devices (e.g. vehicular devices, etc.) with different requirements. Hence, as one approach to reach this, a shift from the current network of entities architecture to a network of capabilities architecture is considered.

In order to achieve this, a concept called network slicing is employed. Network slicing describes the idea of providing multiple isolated network slices for a variety of services on a common infrastructure. For example, slicing is based on using virtualization technology to architect, partition and organize computing and communication resources of a physical infrastructure to enable flexible support of diverse use case realizations. With network slicing, one physical network is sliced into multiple virtual networks, each architected and optimized for a specific requirement and/or specific application/service.

For example, a slice is composed of a collection of logical customized network functions that supports the communication service requirements. The operator’s physical network is sliced into multiple virtual and end-to-end networks and each slice is logically isolated. Each slice has a dedicated treatment in terms of performance (e.g. latency, throughput, etc.) or functionality (e.g. resiliency, security, etc.). In the following, different exemplifying embodiments will be described using, as an example of a communication network to which the embodiments may be applied, a communication network architecture based on 3GPP standards, such as 5G communication networks, without restricting the embodiments to such architectures, however. It is obvious for a person skilled in the art that the embodiments may also be applied to other kinds of communication networks having suitable means by adjusting parameters and procedures appropriately, e.g. 4G networks, WiFi, worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, mobile ad-hoc networks (MANETs), wired access, etc.. Furthermore, without loss of generality, the description of some examples of embodiments is related to a mobile communication network, but principles of the invention can be extended and applied to any other type of communication network, such as a wired communication network.

The following examples and embodiments are to be understood only as illustrative examples. Although the specification may refer to“an",“one", or“some” example(s) or embodiment(s) in several locations, this does not necessarily mean that each such reference is related to the same example(s) or embodiment(s), or that the feature only applies to a single example or embodiment. Single features of different embodiments may also be combined to provide other embodiments. Furthermore, terms like“comprising” and “including” should be understood as not limiting the described embodiments to consist of only those features that have been mentioned; such examples and embodiments may also contain features, structures, units, modules etc. that have not been specifically mentioned.

A basic system architecture of a (tele)communication network including a mobile communication system where some examples of embodiments are applicable may include an architecture of one or more communication networks including wireless access network subsystem(s) and core network(s). Such an architecture may include one or more communication network control elements or network functions, access network elements, radio access network elements, access service network gateways or base transceiver stations, such as a base station (BS), an access point (AP), a NodeB (NB), an eNB or a gNB, a distributed or a centralized unit, which control a respective coverage area or cell(s) and with which one or more communication stations such as communication elements, user devices or terminal devices, like a UE, or another device having a similar function, such as a modem chipset, a chip, a module etc., which can also be part of a station, an element, a function or an application capable of conducting a communication, such as a UE, an element or function usable in a machine-to-machine communication architecture, or attached as a separate element to such an element, function or application capable of conducting a communication, or the like, are capable to communicate via one or more channels for transmitting several types of data in a plurality of access domains. Furthermore, core network elements or network functions, such as gateway network elements/functions, mobility management entities, a mobile switching center, servers, databases and the like may be included.

The general functions and interconnections of the described elements and functions, which also depend on the actual network type, are known to those skilled in the art and described in corresponding specifications, so that a detailed description thereof is omitted herein. However, it is to be noted that several additional network elements and signaling links may be employed for a communication to or from an element, function or application, like a communication endpoint, a communication network control element, such as a server, a gateway, a radio network controller, and other elements of the same or other communication networks besides those described in detail herein below.

A communication network architecture as being considered in examples of embodiments may also be able to communicate with other networks, such as a public switched telephone network or the Internet. The communication network may also be able to support the usage of cloud services for virtual network elements or functions thereof, wherein it is to be noted that the virtual network part of the telecommunication network can also be provided by noncloud resources, e.g. an internal network or the like. It should be appreciated that network elements of an access system, of a core network etc., and/or respective functionalities may be implemented by using any node, host, server, access node or entity etc. being suitable for such a usage.

Furthermore, a network element, such as communication elements, like a UE, a terminal device, control elements or functions, such as access network elements, like a base station (BS), an gNB, a radio network controller, a core network element or network functions, such as a gateway element, other network elements as well as corresponding functions as described herein, and other elements, functions or applications may be implemented by software, e.g. by a computer program product for a computer, and/or by hardware. For executing their respective processing, correspondingly used devices, nodes, functions or network elements may include several means, modules, units, components, etc. (not shown) which are required for control, processing and/or communication/signaling functionality. Such means, modules, units and components may include, for example, one or more processors or processor units including one or more processing portions for executing instructions and/or programs and/or for processing data, storage or memory units or means for storing instructions, programs and/or data, for serving as a work area of the processor or processing portion and the like (e.g. ROM, RAM, EEPROM, and the like), input or interface means for inputting data and instructions by software (e.g. floppy disc, CD-ROM, EEPROM, and the like), a user interface for providing monitor and manipulation possibilities to a user (e.g. a screen, a keyboard and the like), other interface or means for establishing links and/or connections under the control of the processor unit or portion (e.g. wired and wireless interface means, radio interface means including e.g. an antenna unit or the like, means for forming a radio communication part etc.) and the like, wherein respective means forming an interface, such as a radio communication part, can be also located on a remote site (e.g. a radio head or a radio station etc.). It is to be noted that in the present specification processing portions should not be only considered to represent physical portions of one or more processors, but may also be considered as a logical division of the referred processing tasks performed by one or more processors.

It should be appreciated that according to some examples, a so-called“liquid” or flexible network concept may be employed where the operations and functionalities of a network element, a network function, or of another entity of the network, may be performed in different entities orfunctions, such as in a node, host or server, in a flexible manner. In other words, a“division of labor” between involved network elements, functions or entities may vary case by case.

Fig. 1 shows a diagram illustrating a communication network configuration in which examples of embodiments of the invention are implementable. Specifically, Fig. 1 shows an architecture of a communication network including a next generation core network structure.

While in communication networks such as 4G networks protocols and reference points are defined for each entity (such as Mobility Management Entity (MME), Serving Gateway (S- GW), and Packet Data Network Gateway (P-GW)), in Next Generation networks like 5G networks protocols and reference points are defined for network functions (NF) and reference points connecting NFs.

Basically, there are two ways of representing a next generation architecture. One is a so- called a point-to-point architecture which is the basis of the configuration of Fig. 1. Another representation is a so-called a service-based architecture. The point-to-point architecture is similar a traditional 3GPP architecture, as it defines functions and interfaces between them. On the other hand, the service-based architecture incorporates basically the same functional elements and the same user-plane processing path between a UE and an external data networks, but in the control plane, a services model is used in which components query an NF repository function to discover and communicate with each other. This is more related to a cloud-native networking concept in which libraries of functions can be requested from a virtualized network function catalog and composed into end-to-end service chains on demand.

Generally, NF can be implemented either as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, or as a virtualized function instantiated on an appropriate platform, e.g., a cloud infrastructure.

As shown in Fig. 1 , a communication element such as a user equipment (UE) 10 is connected to a RAN or access network (AN) 20 and to an access and mobility function (AMF) 50. The RAN 20 represents a base station (BS) using a NR RAT and/or an evolved LTE base station, while AN 20 is a general base station including e.g. non-3GPP access, e.g., Wi-Fi.

It is assumed that UE 10 supports multi-connectivity communication in order to imply a steering algorithm for at least two radio legs.

The core network architecture shown in Fig. 1 applied for a 5G network comprises various NFs. As shown in Fig. 1 , the CN NFs comprises the AMF 50, a session management function (SMF) 40, a policy control function (PCF) 60, an application function (AF) 90, an authentication server function (AUSF) 70, one or more user plane functions (UPF) 30/35, and a user data management (UDM) 80.

The AMF 50 provides UE-based authentication, authorization, mobility management, etc. A UE (e.g. UE 10) even using multiple access technologies is basically connected to a single AMF because the AMF 50 is independent of the access technologies.

The SMF 40 sets up and manages sessions according to network policy. The SMF 40 is responsible, for example, for session management and allocates IP addresses to UEs. Furthermore, it selects and controls the UPF 30/35 for data transfer. That is, the SMF 40 can configure different UPFs, e.g. the UPF 35 in a mobile edge computing (MEC) entity or the UPF 30 in a central cloud entity. It is to be noted that the SMF 40 controls the UPFs 30/35 via an N4 interface. It is to be noted that it is also possible that in case UE 10 UE has e.g. multiple sessions, different SMFs may be allocated to each session to manage them individually and possibly provide different functionalities per session.

The UPF 30/35 can be deployed in various configurations and locations, according to the service type. As indicated in Fig. 1 , an UPF can be located either in the central cloud (UPF 30) or in a MEC environment (UPF 35). Functions of the UPF 30/35 are e.g. QoS handling for user plane, packet routing and forwarding, packet inspection and policy rule enforcement, traffic accounting and reporting.

The PCF 60 provides a policy framework incorporating network slicing, roaming and mobility management, similar to a policy and charging rules function in a 4G network.

The AF 90 provides information on the packet flow to the PCF 60 in order to support QoS. Based on the information, the PCF 60 determines policies about mobility and session management to make the AMF 50 and the SMF 40 operate properly.

The AUSF 70 stores and provides data for authentication of the UE 10. The UDM 80 stores and provides subscription data of the UE 10, similar to an home subscriber server (HSS) in 4G networks.

Furthermore, data networks 100 (e.g. the Internet) and 1 10 (e.g. a local data network) are shown in Fig. 1 which are not part of the core network architecture, for providing access to the Internet or to operator services.

Furthermore, as shown in Fig. 1 , the NFs are connected by means of so-called reference points N1 to N 15. This representation of reference points N1 to N14 is used for illustrating how call flows are developed. For example, N1 is defined to carry signaling between the UE 10 and the AMF 50. The reference point for connecting between the RAN/AN 20 and the AMF 50 is defined as N2, and the reference point between RAN/AN 20 and the UPF 30/35 is defined as N3, respectively. A reference point N 1 1 is defined between the AMF 50 and the SMF 40 so that SMF 40 is controllable by the AMF 50. Reference point N4 is used by the SMF 40 and the UPF 30/35 so that the UPF 30/35 can be set using the control signal generated by the SMF 40, and the UPF 30/35 can report its state to the SMF 40. Reference point N9 is the reference point for the connection between different UPFs, and reference point N14 is the reference point connecting between different AMFs, respectively. Reference point N15 and N7 are defined for connecting the PCF 60 to the AMF 50 and the SMF 40, respectively, so that the PCF 60 can apply policy to the AMF 50 and the SMF40, respectively. Reference point N12 to AUSF 70 is required for the AMF 50 to perform authentication of the UE 10. Reference points N8 and N10 are defined because the subscription data of the UE 10 is required for the AMF 50 and the SMF 40, respectively. Reference point N5 is defined for connecting between the AF 90 and the PCF 60, and reference point N13 is defined for connecting between the AUSF 70 and the UDM 80. Reference points N6 are defined for connecting between the UPFs 30/35 and the DN 100/1 10, respectively.

It is to be noted that in the network configuration as shown in Fig. 1 a separation of control and user planes is considered. The user plane carries user traffic while the control plane carries signaling in the network. In Fig. 1 , the UPF 30/35 is in the user plane and the AMF 50, the SMF 40, the PCF 60, the AF 90, the AUSF 70 and the UDM 80 are in the control plane. Separating the user and control planes guarantees each plane resource to be scaled independently. It also allows UPFs to be deployed separately from control plane functions in a distributed fashion. For example, UPFs can be deployed very close to RAN or UEs to shorten a round trip time (RTT) between the UE and data network for some applications requiring low latency.

Generally, each NF interacts with another NF directly, but is it also possible that an intermediate function is used for routing messages from one NF to another NF. In the control plane, a set of interactions between two NFs is defined as service so that its reuse is possible. The user plane supports interactions such as forwarding operations between different UPFs.

For traffic steering of data in a communication connection, it is possible to use different network elements or functions. In a configuration as shown in Fig. 1 , traffic steering can be conducted, for example, by the AMF. Another possibility is to use the UPF 30/35 for traffic steering, i.e. to select which network slice or communication connection slice (e.g. a radio slice) is to be used.

For example, the UPF 30 can make steering decisions of the used radio or radio slices in DL direction in a manner as described below.

When a procedure begins, the AMF 50 and SMF 40 may initially cause transmission of an initial setup request requesting a tunnel identifier for packets that will be sent via a tunnel to the RAN/AN 20. The RAN/AN 20 then allocates a tunnel identifier and sends this tunnel identifier back to the UPF 30. The UPF may then inspect the packets to be sent in order to determine the QoS classification that is needed, e.g. by performing a DPI or other technologies. After the QoS classification associated with the packets is determined, the packets will be assigned a tunnel identifier. The UPF 30 then causes the one or more packets to be transmitted via the tunnel to the RAN/AN 20. Upon receiving the one or more packets associated with a tunnel identifier, the RAN/AN 20 identifies the QoS classification for the one or more packets, e.g. based on predefined bits of the tunnel identifier. The RAN/AN 20 can receive the packets for a plurality of applications associated with different QoS classifications via the same tunnel. After the QoS classification has been identified, the RAN/AN 20 causes the one or more packets to be transmitted and/or further processed in accordance with the QoS classification. This further transmission may be done using different radios that provide different QoS levels in order to deliver a plurality of packets from different applications with different QoS classifications to UE 10 with the packets being handled in accordance with the different corresponding QoS levels even though the packets were transmitted via the same tunnel.

Basically, it is preferable to run traffic steering and radio selection algorithms in the central cloud or in the MEC where there usually is more computing power. The reason is, amongst others, that algorithms used for DL packet prioritization and radio slice selection often require DPI which is a resource greed process. CN functions located in a central cloud or MEC entities offer a good platform for such a process since there is usually sufficient computing power to execute e.g. the DPI.

When the UPF 30/35 in the core network executes such a processing including e.g. radio slice selection, it is necessary for the UPF 30/35 to know about all possible radios and radio slices in use as well as capabilities of them. The intelligence and required subscriber and network information are available in the core network NFs, e.g. in the SMF 40, the PCF 60 and the UDM 80.

On the other hand, as indicated above, the SMF 40 configures the UPFs both in the MEC and in the central cloud via N4 interface by means of a corresponding N4 PDU created in the SMF 40. Hence, according to examples of embodiments of the invention, the SMF 40 uses information received e.g. from the PCF 60, the UDM 80 and/or being available in the SMF 40 for creating a suitable information element (e.g. in the form of a N4 PDU) and deliver this information to the UPF 30/35 in order to enable traffic steering processing. In other words, according to examples of embodiments of the invention, the interface between the CP CN function like the SMF 40 and the UP CN function like the UPF 30/35 (which shall execute traffic steering processing), such as the N4 reference point, is configured to provide information about the possible radio slices that can be used for a specific UE or a related flow. Therefore, the UPF 30/35 is able to use improved steering algorithms since it has improved knowledge about radios and radio slices being available.

According to examples of embodiments of the invention, in order to enable the UPF 30/35 to make those improved decision based on steering algorithms usable for radio slice selection, the interface (e.g. N4) between the SMF and the UPFs is adapted.

In this context, it is to be noted that the radio slice selection based on e.g. DPI is further preferably executed by the UPF since the UPF executes packet inspection of DL data packets e.g. due to charging. Furthermore, it is also preferable to provide the required information (e.g. the needed subscriber specific information) from the CP CN side to the UPF (and hence to locate the decision process in the UPF) compared e.g. to a RAN element since a distance between the CN and RAN can be long so it is faster to make local changes in the core network.

In the following, examples of embodiments for generating and providing the information element to the UPF 30/35 are described.

Fig. 2 shows a diagram illustrating an information element structure according to some examples of embodiments. The information element according to Fig. 2 illustrates an example where the information element is added to a specified signaling based on existing standards, such as a signaling using a Sx interface (see also specification 3GPP TS 29.244).

In detail, it is proposed to modify an interface that already supports carrying of an information element like DL Transport Level Marking IE. This information element is transported between the CP CN side and the UP CN side during a session establishment signaling and a session modification or update signaling.

The existing information element like the DL Transport Level Marking IE is used, for example, to deliver a traffic flow template specifying parameters and operations for a packet data protocol context. For example, a ToS/Traffic Class mask field is delivered to the UPF by this IE. By means of this information, types of service and the type of data included in the packet (e.g. prioritized data) are identified. Furthermore, it is possible to set a GTP-U Service Class Indicator extension header for service indication towards GERAN. As shown in Fig. 2, an existing IE, such as the DL Transport Level Marking IE, includes 7+n octets. Octets 1 to 2 indicate the type of the IE (in the shown example type is“30”). Octets 3 to 4 indicate a length of the IE, i.e. defines the value of n. Octets 5 to 6 indicate e.g. the TFT information, or an information element according to examples of embodiments of the invention. Octets 7 to n are present only when specified and can include, for example, further parts of the information element carried in octets 5 and 6.

According to examples of embodiments of the invention, the existing IE like the DL Transport Level Marking IE is modified in such a manner that the same IE can be used also to deliver radio slice / QoS information. That is, in the example shown in Fig. 2, one of the information elements ToS, Traffic Class, and radio QoS marker is included at a time.

According to examples of embodiments, the radio slice / QoS information is provided, for example, during the sessions establishment to the UPF 30 so as to enable the selection of the radio slice to be used.

Furthermore, according to examples of embodiments, the information element for the radio slice / QoS information can also be provided to the UPF 30/35 during a session update, e.g. to restrict a subscriber or an application to use a specific radio slice (e.g. if subscribers quota for a specific radio service has been exceeded). As indicated above, the SMF 40 obtains required information for generating the radio slice / QoS information, e.g. from the SMF itself, the UDM and/or the PCF. Then, the SMF 30 performs a session update procedure, for example, to limit a radio usage.

The information provided by octets 5 to 6 (and 7 etc,) in the example of Fig. 2, i.e. the ToS/Traffic Class/Radio QoS marker, can be encoded on two or more octets as an octet string. The first octet contain, for example, an IPv4 Type-of-Service, an IPv6 Traffic-Class or Radio QoS Marker Class field. The second (and following, if present) octet(s) contain the ToS/Traffic Class mask field/Radio QoS Marker bitmask. The Radio QoS Marker bitmask shows which radio slices are currently available and allowed for the subscriber. For example, bit 1 equals to radio slice 1 and so on. When the UE 10 moves in the network, available radio slices may change. This information is updated to the UPF 30/35 by means of this information element. Also, if the user quota for a specific slice gets full it will be removed from the allowed radio slice list of the UPF 30/35. As indicated above, the IE can be included on both Sx session establishment and modification messages. In the following, another option for providing the information element is described.

In contrast to the example shown in Fig. 2, where an existing information element is modified, it is also possible to define a completely new information element which is transported in an interface between the CP CN side and the UP CN side, e.g. in a Sx interface.

The new information element includes the following information.

One type of information is an indication of available communication connection (e.g. radio) slices for the subscriber (UE 10), i.e. for example radio characteristics of the respective radio slice(s) and an indication whether the radio or radio slice provides a guaranteed bitrate or not.

A further type of information is an indication of (all) available communication connection slices, e.g. of all radio slices in the RAN 20; for example, in case of emergency, all possible resources (e.g. radios) can be used even if the user is not subscribed to use those.

That is, the information element provides information which communication connection slices (e.g. radio slices) are allowed for the subscriber (this represents a static information), and information about the current communication connection status (e.g. status of the radio (this is a dynamic information, i.e. the radios being available for the UE in total may change when UE moves).

Furthermore, the new information element includes information allowing a mapping between a DL marker (TFT) and QoS requirements so that the UPF 30 can make radio selections for DL packets. That is, a mapping between e.g. application traffic and preferred communication connection slice(s) is created, so that, for example, VoIP traffic can be always steered to some specific radio slice. For that, DL marker is needed.

It is to be noted that a coding used for the new information element may be the same or different to the coding of the radio QoS marker defined in connection with Fig. 2.

Thus, according to examples of embodiments of the invention, communication connection slice related information available at the CP CN side, such as radio slice selection specific information, is delivered to the UPF 30 which uses it for a radio slice selection for each DL packet on the basis of subscriber information, radio status and application specific requirements.

It is to be noted that even though the above described examples of embodiments are related to an interface between the CP CN side and the UP CN side like the 3GPP Sx interface, the principles described above are applicable also with other types of interfaces, such as 5G variants of the above defined interface for a N4 reference point or the like.

According to further examples of embodiments, it is also conceivable that there are multiple possible network functions which are configured to execute a traffic steering procedure and hence a radio slice selection in the DL direction. For example, several UPFs or other NFs can be configured to execute a corresponding processing. For example, it is possible that in future 5G networks traffic steering can happen in multiple NFs (not only in the UPF). Therefore, according to examples of embodiments of the invention, a network function is provided that is able to coordinate and control that only one instance (e.g. one UPF or another NF) is allowed to steer the traffic at a time. As one example, the coordination can be done by the SMF 40 or another CN element or function.

Fig. 3 shows a flow chart of a communication connection control procedure according to some examples of embodiments. Specifically, the example according to Fig. 3 is related to a procedure conducted by a control plane core network control element or function, such as the SMF 40 as shown in connection with Fig. 1.

In S100, an information element including information related to at least one communication connection slice selectable for a DL packet transmission towards a communication element or function, such as UE 10, is generated.

According to some examples of embodiments, data used for generating the information element are obtained from at least one of a core network control element or function configured for session management, such as the SMF 40 in Fig. 1 , a core network control element or function configured for user data management, such as the UDM 80 in Fig. 1 , and a core network control element or function configured for policy control, such as the PCF 60 in Fig. 1.

Furthermore, according to some examples of embodiments, the information element includes information indicating which of a plurality of communication connection slices is allowed to be selected for a specific session in which the DL packet transmission is executed. In addition, the information element includes information indicating a transmission characteristic of the at least one communication connection slice, such as a radio characteristic.

Moreover, according to some examples of embodiments, the information element further indicates whether the at least one communication connection slice has a guaranteed bandwidth.

In addition, according to some examples of embodiments, the information element further indicates all available communication connection slices, for example of RAN 20 communicating with the communication element such as the UE 10, irrespective of whether or not they are allowed to be selected for the specific session.

Furthermore, according to some examples of embodiments, the information element further indicates information enabling a mapping between a content of the information element and QoS requirements for the DL packet transmission, in order to create a mapping between a traffic type of the communication connection (e.g. VoIP) and the selected communication connection slice (e.g. a communication connection slice adapted to VoIP communication connection).

In S1 10, the information element generated in S100 is transmitted to a network control element or function, such as the UPF 30 in Fig. 1 , which is configured to conduct a traffic steering processing for selecting a communication connection slice for a DL packet transmission.

According to some examples of embodiments, transmission of the information element to the network control element or function configured to conduct a traffic steering processing for selecting a communication connection slice for a DL packet transmission is caused in a session establishment procedure or in a session update procedure.

Moreover, according to some examples of embodiments, the transmission of the information element to the network control element orfunction configured to conduct a traffic steering processing for selecting a communication connection slice for a DL packet transmission is caused by using a DL transport level marking signaling (e.g. an IE as shown in Fig. 2) transmitted via an interface between a control plane network control element or function and a user plane network control element orfunction (for example, the N4 interface between SMF 40 and UPF 30 in Fig. 1 ). The information element is included in the DL transport level marking signaling in place of a type of service indication or a traffic class indication.

Alternatively, according to some examples of embodiments, the transmission of the information element to the network control element orfunction configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission is done by using a dedicated signaling (i.e. different to a DL transport level marking IE) which is transmitted via an interface between a control plane network control element or function and a user plane network control element or function (for example, the N4 interface between SMF 40 and UPF 30 in Fig. 1 ).

Furthermore, according to some examples of embodiments, an entity orfunction is provided which is configured to decide, in case to there is a plurality of network control elements or functions configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission (e.g. a plurality of UPFs as shown in Fig. 1 or other network element or functions being different to the UPF 30), which of the plurality of network control elements or functions is allowed to conduct the traffic steering processing. When such a decision is made, an indication to the plurality of network control elements or function for informing about the decision.

Moreover, according to some examples of embodiments, the network control element or function configured to conduct the traffic steering processing is included in a user plane core network control element or function (such as the UPF 30 in Fig. 1 ) or in a mobile edge computing network control element or function (such as the UPF (MEC) 35 in Fig. 1 ). On the other hand, according to some examples of embodiments, the communication connection slice for the downlink packet transmission includes a radio slice, and the information element is transmitted via an interface between a control plane core network control element or function and a user plane core network control element or function.

Fig. 4 shows a flow chart of a communication connection control procedure according to some examples of embodiments; Specifically, the example according to Fig. 4 is related to a procedure conducted by a user plane core network control element or function or a mobile edge computing network control element or function, such as the UPF 30 and the UPF(MEC) 35 as shown in connection with Fig. 1 .

In S200, according to some examples of embodiments, an information element including information related to at least one communication connection slice selectable for a DL packet transmission towards a communication element or function, such as the UE 10 in Fig. 1 , is received and processed.

According to some examples of embodiments, the information element includes information indicating which of a plurality of communication connection slices is allowed to be selected for a specific session in which the DL packet transmission is executed. Furthermore, according to some examples of embodiments, the information element includes information indicating a transmission characteristic of the at least one communication connection slice, such as a radio characteristic.

Furthermore, according to some examples of embodiments, the information element further indicates whether the at least one communication connection slice has a guaranteed bandwidth.

In addition, according to some examples of embodiments, the information element further indicates all available communication connection slices, for example of RAN 20 communicating with the communication element such as the UE 10, irrespective of whether or not they are allowed to be selected for the specific session.

Moreover, according to some examples of embodiments, the information element further indicates information enabling a mapping between a content of the information element and QoS requirements for the DL packet transmission, in order to create a mapping between a traffic type of the communication connection (e.g. VoIP) and the selected communication connection slice (e.g. a communication connection slice adapted to VoIP communication connection).

According to some examples of embodiments, the information element is received and processed in a session establishment procedure or in a session update procedure.

Furthermore, according to some examples of embodiments, the information element is received by a DL transport level marking signaling (e.g. an IE as shown in Fig. 2) transmitted via an interface between a control plane network control element or function and a user plane network control element or function (for example, the N4 interface between SMF 40 and UPF 30/35 in Fig. 1 ). The information element is included in the DL transport level marking signaling in place of a type of service indication or a traffic class indication. Alternatively, according to some examples of embodiments, the information element is received by a dedicated signaling (i.e. different to the DL transport level marking IE of Fig. 2) which is transmitted via an interface between a control plane network control element or function and a user plane network control element or function (for example, the N4 interface between SMF 40 and UPF 30/35 in Fig. 1 ).

In S210, a traffic steering processing for selecting a communication connection slice for a DL packet transmission is executed on the basis of the received information element.

For example, according to some examples of embodiments, for conducting the traffic steering processing, a packet inspection (e.g. a DPI) is conducted so as to determine a QoS requested for a packet to be transmitted in DL direction. Then, a communication connection slice for the DL packet transmission is selected by considering the requested QoS and the information obtained from the information element.

According to some examples of embodiments, in case there is a plurality of network control elements or functions configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission (e.g. a plurality of UPFs as shown in Fig. 1 or other network element or functions being different to the UPF 30), an indication regarding an allowance to conduct the traffic steering processing is received and processed. For example, the traffic steering processing of S210 is conducted in case the allowance is received. Otherwise, the traffic steering processing is stopped or not conducted in case the allowance is not received.

According to some examples of embodiments, the information element is received from a core network control element orfunction configured to execute a communication connection related control in control plane core network control element or function, such as the SMF 40 of Fig. 1. Furthermore, according to some examples of embodiments, the communication connection slice for the DL packet transmission includes a radio slice, and the information element is transmitted via an interface between a control plane core network control element or function and a user plane core network control element or function.

Fig. 5 shows a diagram of a network control element or function acting as a core network control element according to some examples of embodiments, e.g. the SMF 40 of Fig. 1 , which is configured to conduct a communication connection control procedure as described in connection with some of the examples of embodiments. It is to be noted that the control element or function, like the SMF 40 of Fig. 1 , may include further elements or functions besides those described herein below. Furthermore, even though reference is made to a network control element or function, the element or function may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and/or circuitry.

The network control element 40 shown in Fig. 5 may include a processing circuitry, a processing function, a control unit or a processor 401 , such as a CPU or the like, which is suitable for executing instructions given by programs or the like related to the communication connection control procedure. The processor 401 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference sign 402 and 403 denotes input/output (I/O) units or functions (interfaces) connected to the processor or processing function 401. The I/O units 402 may be used for communicating with CN elements or functions, such as UDM 80 and PCF 60, as described in connection with Fig. 1 , for example. The I/O units 403 may be used for communicating with the UPF 30/35, as described in connection with Fig. 1 , for example. The I/O units 402 and 403 may be a combined unit including communication equipment towards several entities, or may include a distributed structure with a plurality of different interfaces for different entities. Reference sign 404 denotes a memory usable, for example, for storing data and programs to be executed by the processor or processing function 401 and/or as a working storage of the processor or processing function 401. It is to be noted that the memory 404 may be implemented by using one or more memory portions of the same or different type of memory.

The processor or processing function 401 is configured to execute processing related to the above described communication connection control processing. In particular, the processor or processing circuitry or function 401 includes one or more of the following sub-portions. Sub-portion 4011 is a processing portion which is usable as a portion for generating an information element. The portion 401 1 may be configured to perform processing according to S100 of Fig. 3. Furthermore, the processor or processing circuitry or function 4010 may include a sub-portion 4012 usable as a portion for transmitting the information element. The portion 4012 may be configured to perform a processing according to S110 of Fig. 3.

Fig. 6 shows a diagram of a network element or function acting as a core network control element according to some examples of embodiments, e.g. the UPF 30 (or UPF(MEC) 35) of Fig. 1 , which is configured to conduct a communication connection control procedure as described in connection with some of the examples of embodiments. It is to be noted that the network element or function, like the UPF 30 of Fig. 1 , may include further elements or functions besides those described herein below. Furthermore, even though reference is made to a network element or function, the element or function may be also another device or function having a similar task, such as a chipset, a chip, a module, an application etc., which can also be part of a network element or attached as a separate element to a network element, or the like. It should be understood that each block and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and/or circuitry.

The network element 30 shown in Fig. 6 may include a processing circuitry, a processing function, a control unit or a processor 301 , such as a CPU or the like, which is suitable for executing instructions given by programs or the like related to the communication connection control procedure. The processor 301 may include one or more processing portions or functions dedicated to specific processing as described below, or the processing may be run in a single processor or processing function. Portions for executing such specific processing may be also provided as discrete elements or within one or more further processors, processing functions or processing portions, such as in one physical processor like a CPU or in one or more physical or virtual entities, for example. Reference sign 302 and 303 denotes input/output (I/O) units orfunctions (interfaces) connected to the processor or processing function 301. The I/O units 302 may be used for communicating with CN elements orfunctions, such as SMF 40, as described in connection with Fig. 1 , for example. The I/O units 303 may be used for communicating with the RAN 20, as described in connection with Fig. 1 , for example. The I/O units 302 and 303 may be a combined unit including communication equipment towards several entities, or may include a distributed structure with a plurality of different interfaces for different entities. Reference sign 304 denotes a memory usable, for example, for storing data and programs to be executed by the processor or processing function 301 and/or as a working storage of the processor or processing function 301 . It is to be noted that the memory 304 may be implemented by using one or more memory portions of the same or different type of memory. The processor or processing function 301 is configured to execute processing related to the above described communication connection control processing. In particular, the processor or processing circuitry or function 301 includes one or more of the following sub-portions. Sub-portion 3011 is a processing portion which is usable as a portion for receiving and processing an information element. The portion 301 1 may be configured to perform processing according to S200 of Fig. 4. Furthermore, the processor or processing circuitry or function 3010 may include a sub-portion 3012 usable as a portion for conducting a traffic steering processing. The portion 3012 may be configured to perform a processing according to S210 of Fig. 4.

It is to be noted that examples of embodiments of the invention are applicable to various different network configurations. In other words, the examples shown in the above described figures, which are used as a basis for the above discussed examples, are only illustrative and do not limit the present invention in any way. That is, additional further existing and proposed new functionalities available in a corresponding operating environment may be used in connection with examples of embodiments of the invention based on the principles defined.

According to a further example of embodiments, there is provided, for example, an apparatus for use by a core network control element or function configured to execute a communication connection related control, the apparatus comprising means configured to generate an information element including information related to at least one communication connection slice selectable for a downlink packet transmission towards a communication element or function, and means configured to cause transmission of the information element to a network control element or function configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission.

Furthermore, according to some other examples of embodiments, the above defined apparatus may further comprise means for conducting at least one of the processing defined in the above described methods, for example a method according that described in connection with Fig 3.

According to a further example of embodiments, there is provided, for example, an apparatus for use by a network control element or function configured to conduct a traffic steering processing in a communication connection, the apparatus comprising means configured to receive and process an information element including information related to at least one communication connection slice selectable for a downlink packet transmission towards a communication element or function, and means configured to conduct a traffic steering processing for selecting a communication connection slice for a downlink packet transmission on the basis of the received information element.

Furthermore, according to some other examples of embodiments, the above defined apparatus may further comprise means for conducting at least one of the processing defined in the above described methods, for example a method according that described in connection with Fig 4.

It should be appreciated that

- an access technology via which traffic is transferred to and from an entity in the communication network may be any suitable present or future technology, such as WLAN (Wireless Local Access Network), WiMAX (Worldwide Interoperability for Microwave Access), LTE, LTE-A, 5G, Bluetooth, Infrared, and the like may be used; additionally, embodiments may also apply wired technologies, e.g. IP based access technologies like cable networks or fixed lines.

- embodiments suitable to be implemented as software code or portions of it and being run using a processor or processing function are software code independent and can be specified using any known or future developed programming language, such as a high-level programming language, such as objective-C, C, C++, C#, Java, Python, Javascript, other scripting languages etc., or a low-level programming language, such as a machine language, or an assembler.

- implementation of embodiments is hardware independent and may be implemented using any known or future developed hardware technology or any hybrids of these, such as a microprocessor or CPU (Central Processing Unit), MOS (Metal Oxide Semiconductor), CMOS (Complementary MOS), BiMOS (Bipolar MOS), BiCMOS (Bipolar CMOS), ECL (Emitter Coupled Logic), and/or TTL (Transistor-Transistor Logic).

- embodiments may be implemented as individual devices, apparatuses, units, means or functions, or in a distributed fashion, for example, one or more processors or processing functions may be used or shared in the processing, or one or more processing sections or processing portions may be used and shared in the processing, wherein one physical processor or more than one physical processor may be used for implementing one or more processing portions dedicated to specific processing as described,

- an apparatus may be implemented by a semiconductor chip, a chipset, or a (hardware) module including such chip or chipset; - embodiments may also be implemented as any combination of hardware and software, such as ASIC (Application Specific 1C (Integrated Circuit)) components, FPGA (Field- programmable Gate Arrays) or CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components.

- embodiments may also be implemented as computer program products, including a computer usable medium having a computer readable program code embodied therein, the computer readable program code adapted to execute a process as described in embodiments, wherein the computer usable medium may be a non-transitory medium. Although the present invention has been described herein before with reference to particular embodiments thereof, the present invention is not limited thereto and various modifications can be made thereto.