WO2017135859A1

WO2017135859A1 - Network nodes and methods performed therein

Info

Publication number: WO2017135859A1
Application number: PCT/SE2016/050106
Authority: WO
Inventors: Angelo Centonza; Jari Vikberg; Oscar Zee; Paul Schliwa-Bertling
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2016-02-05
Filing date: 2016-02-12
Publication date: 2017-08-10

Abstract

Embodiments herein relate to a method performed by a Radio Access Network, RAN, node (12), for enabling connection setup for a wireless device 10 in a communication network (1). The communication network (1) comprises a first network and a second network. The RAN node (12) is associated with the first and the second network. A first core network node (19) is associated with the first network and a second core network node (20) is associated with the second network. The RAN node receives a paging request from a core network node (19), which paging request comprises an indication of a network identity for the network associated with the core network node, a core network node IDentity, ID, associated with the core network node (19) and a wireless device identity of the wireless device (10) which is being paged. The RAN node transmits the paging request to the wireless device (10) associated to the wireless device identity, which paging request indicates the network identity for the network associated with the core network node (19), the core network node ID associated with the core network node (19), and the wireless device identity.

Description

NETWORK NODES AND METHODS PERFORMED THEREIN

TECHNICAL FIELD

Embodiments herein relate to a Radio Access Network, RAN, node, a core network node, a wireless device and methods performed therein for communication. Furthermore, a computer program and a computer readable storage medium are also provided herein. In particular, embodiments herein relate to enabling connection setup for a wireless device in a communication network.

BACKGROUND

In a typical communication network, wireless devices, also known as wireless communication devices, mobile stations, stations (STA) and/or user equipments (UE), communicate via a Radio Access Network (RAN) to one or more core networks (CN). The RAN covers a geographical area which is divided into service areas or cell areas, with each service area or cell area being served by a radio network node such as a radio access node e.g., a Wi-Fi access point or a radio base station (RBS), which in some networks may also be denoted, for example, a "NodeB" or "eNodeB". A service area or cell area is a geographical area where radio coverage is provided by the radio network node. The radio network node communicates over an air interface operating on radio frequencies with the wireless device within range of the radio network node.

A Universal Mobile Telecommunications System (UMTS) is a third generation telecommunication network, which evolved from the second generation (2G) Global System for Mobile Communications (GSM). The UMTS terrestrial radio access network (UTRAN) is essentially a RAN using wideband code division multiple access (WCDMA) and/or High Speed Packet Access (HSPA) for user equipments. In a forum known as the Third Generation Partnership Project (3GPP), telecommunications suppliers propose and agree upon standards for third generation networks, and investigate enhanced data rate and radio capacity. In some RANs, e.g. as in UMTS, several radio network nodes may be connected, e.g., by landlines or microwave, to a controller node, such as a radio network controller (RNC) or a base station controller (BSC), which supervises and coordinates various activities of the plural radio network nodes connected thereto. This type of connection is sometimes referred to as a backhaul connection. The RNCs and BSCs are typically connected to one or more core networks.

Specifications for the Evolved Packet System (EPS), also called a Fourth

Generation (4G) network, have been completed within the 3^rd Generation Partnership Project (3GPP) and this work continues in the coming 3GPP releases, for example to specify a Fifth Generation (5G) network. The EPS comprises the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), also known as the Long Term Evolution (LTE) radio access network, and the Evolved Packet Core (EPC), also known as System Architecture Evolution (SAE) core network. E-UTRAN/LTE is a variant of a 3GPP radio access network wherein the radio network nodes are directly connected to the EPC core network rather than to RNCs. In general, in E-UTRAN/LTE the functions of an RNC are distributed between the radio network nodes, e.g. eNodeBs in LTE, and the core network. As such, the RAN of an EPS has an essentially "flat" architecture comprising radio network nodes connected directly to one or more core networks, i.e. they are not connected to RNCs. To compensate for that, the E-UTRAN specification defines a direct interface between the radio network nodes, this interface being denoted the X2 interface. EPS is the Evolved 3GPP Packet Switched Domain. Figure 1 is an overview of the EPC architecture. This architecture is defined in 3GPP TS 23.401 v.13.4.0 wherein a definition of a Packet Data Network Gateway (PGW), a Serving Gateway (SGW), a Policy and Charging Rules Function (PCRF), a Mobility Management Entity (MME) and a wireless or mobile device (UE) is found. The LTE radio access, E-UTRAN, comprises one or more eNBs. Figure 2 shows the overall E-UTRAN architecture and is further defined in for example 3GPP TS 36.300 v.13.1.0. The E-UTRAN comprises eNBs, providing a user plane comprising the protocol layers Packet Data Convergence Protocol (PDCP)/Radio Link Control (RLC)/Medium Access Control (MAC)/Physical layer (PHY), and a control plane comprising Radio Resource Control (RRC) protocol in addition to the user plane protocols towards the wireless device. The radio network nodes are interconnected with each other by means of the X2 interface. The radio network nodes are also connected by means of the S1 interface to the EPC, more specifically to the MME by means of an S1- MME interface and to the S-GW by means of an S1-U interface.

Figure 3 shows a management system architecture in the communications network. The node elements (NE), also referred to as eNodeB, are managed by a domain manager (DM), also referred to as the operation and support system (OSS). A DM may further be managed by a network manager (NM). Two NEs are interfaced by X2, whereas the interface between two DMs is referred to as ltf-P2P. The management system may configure the network elements, as well as receive observations associated to features in the network elements. For example, DM observes and configures NEs, while NM observes and configures DM, as well as NE via DM.

By means of configuration via the DM, NM and related interfaces, functions over the X2 and S1 interfaces can be carried out in a coordinated way throughout the RAN, eventually involving the Core Network, i.e. MMEs and S-GWs.

The S1-MME interface is used for control plane between eNodeB/E-UTRAN and MME. The main protocols used in this interface are S1 Application Protocol (S1AP) and Stream Control Transmission Protocol (SCTP). S1AP is the application Layer Protocol between the radio network node and the MME and SCTP for example guarantees delivery of signaling messages between MME and the radio network node. The transport network layer is based on Internet Protocol (IP).

A subset of the S1 interface provided functions are:

S1-interface management functions such as S1 setup, error indication, reset and the radio network node and MME configuration update.

UE Context Management functionality such as Initial Context Setup Function and UE Context Modification Function.

E-UTRAN Radio Access Bearer (E-RAB) Service Management functions e.g. Setup, Modify, Release.

- Mobility Functions for wireless devices in EPS Connection Management

(ECM)-CONNECTED, e.g. Intra-LTE Handover and inter-3GPP-Radio Access Technology (RAT) Handover.

S1 Paging function.

Non Access Stratum (NAS) Signaling Transport function.

Establishment of the S1-MME interface on S1AP protocol level is shown in Figure

4 as the S1 setup procedure. The purpose of the S1 Setup procedure is to exchange application level data needed for the radio network node and the MME to correctly interoperate on the S1 interface. The radio network node may initiate the procedure by sending an S1 SETUP REQUEST message to the MME once it has gained IP

connectivity and it has been configured with at least one Tracking Area Indicator (TAI). The TAI(s) are used by the radio network node to locate IP-addresses of the different MMEs, possibly in different MME pools. The radio network node includes its global radio network node identity and other information in the S1 SETUP REQUEST message. The MME responds with an S1 SETUP RESPONSE message. This S1 SETUP RESPONSE message includes for example the Globally Unique MME identifier(s) (GUMMEI) of the MME.

An Initial Context Setup process is shown in Figure 5. An INITIAL CONTEXT SETUP REQUEST message is sent by the MME to request the setup of a UE context or context of a wireless device. This INITIAL CONTEXT SETUP REQUEST message comprises information related to both the UE context and different E-RABs to be established. For each E-RAB the MME includes E-RAB Quality of Service (QoS) parameters such as QoS Class Identifier (QCI) and Allocation and Retention Priority (ARP). The QCI is a scalar that is used as a reference to radio access node-specific parameters that control bearer level packet forwarding treatment, e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc., and that have been pre-configured by the operator owning the radio network node. Current assumption is that the RAN-CN split is similar for 5G as for 4G, implying an (evolved) S1 interface. An INITIAL CONTEXT SETUP RESPONSE message is sent by eNB to the MME confirming the setup.

Within a LTE/EPC network, there are several identities which are used for distinguishing, which may also be referred to as identifying, elements within the network. An overview of these identities is shown in Figure 6.

The purpose of the Globally Unique Temporary UE Identity (GUTI) is to provide an unambiguous identification of the UE that does not reveal the UE or the user's permanent identity in the Evolved Packet System (EPS). The GUTI also allows the identification of the MME and the network. It can be used by the network and the UE to establish the UE's identity during signaling between the UE and the network in the EPS. The GUTI may have a length of 76 to 80 bits.

The GUTI comprises two main components:

The Globally Unique MME Identifier (GUMMEI) that uniquely identifies the MME which allocated the GUTI; and

· a Temporary Mobile Subscriber Identity called M-TMSI that uniquely

identifies the UE within the MME that allocated the GUTI.

Within the MME, the mobile is identified by the M-TMSI.

The GUMMEI may be constructed from a Mobile Country Code (MCC), a Mobile Network Code (MNC) and an MME Identifier (MMEI). The MMEI is constructed from an MME Group ID (MMEGI) and an MME Code (MMEC).

The GUTI is constructed from the GUMMEI and the M-TMSI.

For paging purposes, the mobile is paged with an S-TMSI, which S-TMSI is constructed from the MMEC and the M-TMSI.

An operator will need to ensure that the MMEC is unique within the MME pool area and, if overlapping pool areas are in use, unique within the area of overlapping MME pools. If the MMEC is not unique within the MME pool, the transmission in the network might be directed to the wrong MME

For the purpose of selecting a core network node to which a UE should be connected to in case a UE context is registered or attached in the serving core network, the UE may signal to the RAN, during a service request or paging response procedure, an S-TMSI or a GUMMEI. A detection of the right CN node may then be performed based on these parameters.

The GUTI supports subscriber identity confidentiality, and, in the shortened S-

TMSI form, enables more efficient radio signalling procedures, e.g. during Paging and/or Service Request.

The format and size of the GUTI is therefore the following:

<GUTI> = <GUMMEI><M-TMSI>,

where

<GUMMEI> = <MCC><MNC><MME Identifier

and where

<MME Identifier = <MME Group ID><MME Code>. The wireless communication industry is at the verge of a unique business crossroads. The growing gap between capacity and demand is an urgent call for new approaches and alternative network technologies to enable mobile operators to achieve more with less. Today, mobile broadband data is growing at an annual rate of 40-50 percent per year in the U.S. and other regions globally. Mobile service providers address these rapidly expanding traffic volumes through deployment of additional network functions, which will be a significant capital expenditure (CAPEX) challenge. The nature of the mobile broadband data traffic is also evolving with new services including new video applications, connected cars and the Internet of Things (loT). This rapid capacity growth and increasing traffic diversity in LTE networks stresses the assumptions of existing network architectures and operational paradigms. As expected by leading operators and vendors in Next Generation Mobile

Networks (NGMN) association, diverse applications or services are expected to be provided by 5G networks. 5G will support countless emerging use cases with a high variety of applications and variability of their performance attributes: from delay-sensitive video applications to ultra-low latency, from high speed entertainment applications in a vehicle to mobility on demand for connected objects, and from best effort applications to reliable and ultra-reliable ones such as health and safety. Furthermore, use cases will be delivered across a wide range of devices, e.g., smartphones, wearables, MTCs, and across a fully heterogeneous environment.

Network Functions Virtualization (NFV) provides a new path that can increase the flexibility required by mobile service providers and network operators to adapt and accommodate this dynamic market environment. NFV is a new operational approach applying well-known virtualization technologies to create a physical Commercial Off-the- Shelf (COTS) distributed platform for the delivery of end-to-end services in the context of the demanding environment of telecom network infrastructure and applications.

Because EPC is critical to the realization and management of all LTE traffic, it is important to consider use cases related to virtualization of the EPC elements. Each individual EPC element also has specific considerations that determine whether to deploy with NFV. Virtualized EPC (vEPC) is a good example: Multiple virtualized network functions (VNF) can be deployed and managed on a Network Functions Virtualization Infrastructure (NFVI) but must cater to performance scalability in both signaling/control plane and user plane, each potentially demanding different levels of NFVI resources. vEPC elements can benefit from more agile deployment and scalability. However, virtual resource monitoring and orchestration, along with service awareness, are essential for implementing elasticity effectively. Due to the nature of telecom networks, service Level Agreements (SLA) will be a key issue for a virtualized mobile core network.

Because virtualization usually leads to a performance trade-off, equipment vendors must optimize data-plane processing to satisfy carrier-grade bandwidth and latency

requirements and sufficient control-plane performance for SLAs needed to ensure availability of regulatory services, such as emergency calls.

VNF is a virtualized network function which serves as a VNF Software for providing virtual network capabilities. A VNF could be decomposed and instantiated in roles such as Virtualized MME (vMME), Virtualized PCRF (vPCRF), Virtualized SGW (vSGW) or Virtualized PDN-GW (vPDN-GW). NFV is seen as an enabler for network slicing and network sharing that is described herein.

Network slicing is about creating logically separated partitions of the network, which may also be referred to as slices or network slices, addressing different business purposes. These network slices are logically separated to a degree that they can be regarded and managed as networks of their own.

Network slicing is a new concept that applies to both LTE Evolution and New 5G RAT, which herein is referred to as NX. The key driver for introducing network slicing is business expansion, i.e. improving the operator's ability to serve other industries, by offering connectivity services with different network characteristics, such as e.g.

performance, security, robustness, and/or complexity.

The current main working assumption is that there will be one shared RAN infrastructure that will connect to several EPC instances, where one EPC instance relates to a network slice. As the EPC functions are being virtualized, it is assumed that an operator will instantiate a new CN when a new slice should be supported.

RAN sharing is based on the possibility for operators to share the same RAN and optionally the same spectrum by means of two standardized architectures, which are shown in Fig. 7. The first architecture is called Mobile Operator Core Network (MOCN) and consists of different participating operators to connect their CN infrastructure to a commonly shared RAN. In this case each participating operator can run CN-RAN procedures from its own managed RAN. A second architecture option is called Gateway Core Network (GWCN) and it consists of the shared RAN connecting to a single shared CN. Participating operators would therefore share the CN as well as the RAN.

The RAN may be managed by one of the participating operators or may be managed by a third party. It may also be possible that the CN infrastructure is managed by one of the participating operators or by a third party or it may be managed in part, i.e. for some nodes, by a third party and in part by the participating operator. Each participating operator has access to a set of resources both in the CN and in the RAN.

When looking at the wide range of applications and use cases that are addressed with a 5G network, it is quite obvious these cannot effectively be addressed with a traditional approach of having a purpose built network for each application. This will lead to high cost for networks and devices as well as inefficient use of valuable frequency resources. Obviously, different use cases put different requirements to future networks. Examples of such requirements may include acceptable interruption time, reliability and availability, acceptable latency, data rate, as well as cost per user. It would be quite difficult or cost-wise impossible to deploy a common network service to fulfill such extremely diverse requirements. In the situation, network slicing was proposed as a concept to fulfill rich requirements from various 5G use cases. Meanwhile, the network slicing concept is getting widely recognition in NGMN. A network slice supports the communication service of a particular connection type with a specific way of handling C- plane and U-plane for the service. A 5G slice could be composed by a collection of 5G network functions and possibly specific RAT with specific settings that are combined together for the specific use case or business model. It should be noted that not all slices contain the same network functions. A specific network service can be instantiated according to on demand requirements for third party users/operators and the business policy between the network service providers and network the service consumers. Thus, an operator may have one physical network infrastructure and one pool of frequency bands, which may support many separate virtualized networks, also called network slices. Each network slice may have unique characteristics for meeting the specific requirements of the use case/s it serves.

A key function of 5G Core network is to allow for flexibility in network service creation, making use of different network functions suitable for the offered service in a specific network slice, e.g. Evolved Mobile Broadband (MBB), Massive Machine Type Communication (MTC), Critical MTC, Enterprise, etc.

In addition to Service optimized networks there are more drivers for Network slicing, such as;

Business expansion by low initial investment: Given the physical infrastructure it is much easier to instantiate another Packet Core instance for the business expansion than to set up a new parallel infrastructure or even integrated nodes

Low risk by no/limited impact on legacy: As the new instance is logically separated from the other network slices, the network slices can also provide resource isolation between each other. Thus introduction of a new isolated network slice will not impact the existing operator services and therefore only provide low risk

Short Time To Market (TTM): The operators are concerned about the time it takes to set up the network for a new service. Slicing of the network for different services/operator use cases provides a separation of concern that can result in a faster setup of a network slice for a certain service as it is separately managed and with limited impact on other network slices Optimized use of resources: Today the network is supporting many different services but with new use cases and more diverging requirements there is a need for optimize the network for the specific type use case. Network slicing allows to match services to optimized network instances, and it also allows for a more optimized use of those specific resources

- Allows for individual network statistics: With service specific network slices and possibly even on the level of individual enterprises, there is a possibility of collecting network statistics specific for a limited and well defined group of users of the network slice. This is not the key driver for slicing but rather a benefit that may be a useful tool

Slicing can also be used to isolate different services in an operator's network. Future networks are expected to support new use cases going beyond the basic support for voice services and mobile broadband currently supported by existing cellular network, e.g. 2G/3G/4G. Some example use cases include:

- Evolution of MBB

> Evolved communication services

> Cloud services

> Extended mobility and coverage

Mission critical Machine Type Communication

> Intelligent traffic systems

> Smart grid

> Industrial applications

Massive Machine Type Communication

> Sensors/actuators

> Capillary networks

- Media

> Efficient on-demand media delivery

> Media awareness

> Efficient support for broadcast services

These use cases are expected to have different performance requirements, e.g. bit-rates, latencies, as well as other network requirements, e.g. mobility, availability, security etc., affecting the network architecture and protocols.

Supporting these use cases could also mean that new players and business relations are needed compared to existing cellular networks. For instance it is expected that future network should address the needs of Enterprise services

Government services, e.g. national and/or public safety

- Verticals industries, e.g. automation, transportation

Residential users

These different users and services are also expected to put new requirements on the network. Fig. 8 shows an example of a network slicing for a case when there exists different network slices in the core network for MBB, Massive MTC and Critical MTC. In other words, the network slices may comprise separate core network instances supporting the different network slices. In addition, it is also possible that parts of the EPC are shared between the different network slices. One such example of shared EPC functionality may be a core network node, such as a MME.

A RAN in a sliced network may be implemented with the following pre-requisites:

• A RAN operator manages a number of eNBs which are comprised in the operators own transport network in the RAN.

· The RAN operator, CN operators and other participating parties in the shared system have mutual Service Level Agreements (SLA).

• The shared network supports a number of coexisting network slices,

wherein each slice is served by part of the overall RAN/CN infrastructure. Each core network node, such as an MME, in the CN can handle one or several slices. The maximum number of core network nodes which can be addressed within a CN operator will be 256 as long as 8-bits MMEC is used, since each core network node requires a unique MMEC.

The aim of the network slicing is therefore to provide a simple tool for cellular operators to introduce new services and features to different industries.

Due to the highly increased number of virtualized networks sharing the

infrastructure of the communications network the capacity of the infrastructure might soon reach its limit. Furthermore, the increased number of parties, such as network operators and/or infrastructure owners, cooperating in the communications network, leads to an increased effort for coordinating different identifiers between the virtualized networks within the communications network in order to avoid wrongful routing of transmissions between the different network entities, such as network nodes and/or network slices. Such coordination is both time consuming and cost intensive for all parties involved. SUMMARY

An object of embodiments herein is to provide a mechanism for improving capacity and reducing the coordination effort of the communication network in an efficient manner. According to an aspect the object is achieved by a method, performed by a Radio

Access Network (RAN) node, for enabling connection setup for a wireless device in a communication network. The communication network comprises a first network and a second network. The RAN node is associated with the first and with the second network. A first core network node is associated with the first network and a second core network node is associated with the second network. The RAN node receives a paging request from a core network node, which paging request comprises an indication of a network identity for the network associated with the core network node, an indication of a core network node IDentity (ID) associated with the core network node and a wireless device ID of the wireless device which is being paged. The RAN node further transmits the paging request to the wireless device associated with the wireless device ID, wherein the paging request indicates the network identity for the network associated with the core network node, the core network node ID associated with the core network node, and the wireless device identity.

According to another aspect the object is achieved by a method performed by a first core network node, for enabling connection setup for a wireless device in a communication network. The communication network comprises a first network and a second network. The first core network node is associated with the first network and a second core network node is associated with the second network. The first core network node is being identified by a first core network node IDentity (ID) and the second core network node is being identified by a second core network node ID. The first and the second core network node IDs are uncoordinated between the first network and the second network. The core network node initiates a connection establishment for the wireless device by transmitting a paging request to a Radio Access Network (RAN) node. The paging request comprises an indication of a network identity for the first network associated with the core network node, the core network node ID and a wireless device identity of the wireless device which is being paged.

According to yet another aspect the object is achieved by a method performed by a wireless device, for establishing a connection to a communication network. The communication network comprises a first network and a second network. The first network is associated with a first core network node and the second network is associated with a second core network node. The first and the second network are further associated to a Radio Access Network (RAN) node. The wireless device receives a paging request from the RAN node. The paging request comprises an indication of a network identity (ID) of the network associated with the core network node, a core network node ID identifying the first core network node 19 and the wireless device identity of the wireless device. The wireless device further transmits a response to the RAN node. The response comprises the network ID of the first network indicated in the paging request, the core network node ID for the core network node indicated in the paging request and the wireless device identity of the wireless device.

According to still another aspect the object is achieved by providing a Radio Access Network (RAN) node for enabling connection setup for a wireless device in a communication network. The communication network comprises a first network and a second network. The RAN node is associated with the first and the second network. A first core network node is associated with the first network and a second core network node is associated with the second network. The RAN node is configured to receive a paging request from a core network node, which paging request comprises an indication of a network identity for the network associated with the core network node, a core network node IDentity (ID) associated with the core network node and a wireless device identity of the wireless device which is being paged. The RAN node is further configured to transmit the paging request to the wireless device which is associated with the wireless device identity. The paging request indicates the network identity for the network associated with the core network node, the core network node ID associated with the core network node and the wireless device identity.

According to a further aspect the object is achieved by providing a first core network node, for enabling connection setup for a wireless device in a communication network. The communication network comprises a first network and a second network. The first core network node is associated with the first network and a second core network node is associated with the second network. The first core network node is being identified by a first core network node IDentity (ID) and the second core network node is being identified by a second core network node ID. The first and the second core network node IDs are uncoordinated between the first network and the second network. The core network node is configured to initiate a connection establishment for the wireless device by transmitting a paging request to a Radio Access Network (RAN) node. The paging request comprises an indication of a network identity for the first network associated with the core network node, the core network node ID and a wireless device identity of the wireless device which is being paged.

According to yet a further aspect the object is achieved by providing a wireless device, for establishing a connection to a communication network. The communication network comprises a first network and a second network. The first network is associated with a first core network node and the second network is associated with a second core network node. The first and the second network are further associated to a Radio Access Network (RAN) node. The wireless device is configured to receive a paging request from the RAN node. The paging request comprises an indication of a network identity (ID) of the network associated with the core network node, a core network node ID identifying the first core network node and a wireless device identity of the wireless device. The wireless device is further configured to transmit a response to the RAN node. The response comprises the network ID of the first network indicated in the paging request, the core network node ID for the core network node indicated in the paging request and the wireless device identity of the wireless device.

It is furthermore provided herein a computer program comprising instructions, which, when executed on at least one processor, cause the at least one processor to carry out any of the methods above, as performed by the first network node or the second network node. It is additionally provided herein a computer-readable storage medium, having stored thereon a computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any of the methods above, as performed by the first network node or the second network node. Embodiments herein introduce an efficient manner of coordinating different identifiers between PLMNs when multiple PLMNs with slices are hosted in the same RAN. By adding a network ID for each network in the different signaling procedures such as paging and service request, the MMECs do not have to be unique across different networks, such as e.g. PLMNs. This allows a reuse of MMEC values. Thereby, a communications network can handle an overall number of MMECs higher than the current limit of 256, which increases the capacity of the network. Further, since MMECs and Slice IDs do not need to be coordinated across different PLMNs cross-PLMN configurations can be minimized, thereby reducing coordination between RAN operator, CN operators (PLMNs) and other participating parties such as e.g. network slice operators. A further advantage is that M-TMSI does not need to be coordinated between core network nodes in different networks. By minimizing the coordination of the different identifiers between the participating parties the costs of running such networks can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described in more detail in relation to the enclosed drawings, in which:

Fig. 1 is a schematic overview depicting a communication network according to prior art; Fig. 2 is a schematic overview depicting a radio access network in connection with a core network;

Fig. 3 is a schematic overview depicting a management system architecture for a

communications network;

Fig. 4 is a signalling scheme according to prior art;

Fig. 5 is a signalling scheme according to prior art;

Fig. 6 is a schematic overview of identities used for distinguishing elements within the network;

Fig. 7 is a schematic overview depicting examples of standardized architectures for sharing Radio Access Networks;

Fig. 8 is a schematic overview depicting an example of network slicing with slice specific core network instances according to prior art;

Fig. 9 is a schematic overview depicting a communication network according to

embodiments herein;

Fig. 10 is a signaling diagram depicting a paging procedure according to embodiments herein.

Fig. 11 is a schematic flowchart depicting a method performed by a RAN node according to a first aspect of embodiments herein;

Fig. 12 is a schematic flowchart depicting a method performed by a core network node according to a first aspect of embodiments herein;

Fig. 13 is a schematic flowchart depicting a method performed by a wireless device

according to a first aspect of embodiments herein; Fig. 14 is a signaling diagram depicting a service request procedure according to embodiments herein.

Fig. 15 is a schematic flowchart depicting a method performed by a wireless device

according to a second aspect of embodiments herein;

Fig. 16 is a schematic flowchart depicting a method performed by a RAN node according to a second aspect of embodiments herein;

Fig. 17 is a schematic flowchart depicting a method performed by a core network node according to a second aspect of embodiments herein;

Fig. 18 is a block diagram depicting a RAN node according to embodiments herein;

Fig. 19 is a block diagram depicting a core network node according to embodiments

herein; and

Fig. 20 is a block diagram depicting a wireless device according to embodiments herein.

DETAILED DESCRIPTION

Embodiments herein relate to communication networks in general. Fig. 9 is a schematic overview depicting a communication network 1. The communication network 1 comprises a RAN and a CN. The communication network 1 may use a number of different technologies, such as Wi-Fi, Long Term Evolution (LTE), LTE-Advanced, 5G, Wideband Code Division Multiple Access (WCDMA), Global System for Mobile

communications/Enhanced Data rate for GSM Evolution (GSM/EDGE), Worldwide

Interoperability for Microwave Access (WiMax), or Ultra Mobile Broadband (UMB), just to mention a few possible implementations. Embodiments herein relate to recent technology trends that are of particular interest in a 5G context, however, embodiments are

applicable also in further development of the existing communication systems such as e.g. 3G and LTE.

In the communication network 1 , wireless devices e.g. a wireless device 10 such as a mobile station, a non-access point (non-AP) STA, a STA, a User Equipment (UE) and/or a wireless terminals, communicate via one or more Access Networks (AN), e.g. RAN, to one or more CNs. It should be understood by those skilled in the art that

"wireless device" is a non-limiting term which means any terminal, wireless

communication terminal, user equipment, Machine Type Communication (MTC) device, Device to Device (D2D) terminal, or node e.g. smart phone, laptop, mobile phone, sensor, relay, mobile tablets or even a base station communicating within a cell. The communication network 1 comprises a radio network node 12 providing radio coverage over a geographical area, a service area 11 , of a radio access technology (RAT), such as LTE, UMTS, Wi-Fi or similar. The radio network node 12 may be a radio access network node such as radio network controller or an access point such as a wireless local area network (WLAN) access point or an Access Point Station (AP ST A), an access controller, a base station, e.g. a radio base station such as a NodeB, an evolved Node B (eNB, eNodeB), a base transceiver station, Access Point Base Station, base station router, a transmission arrangement of a radio base station, a stand-alone access point or any other network unit capable of serving a wireless device within the service area served by the radio network node 12 depending e.g. on the first radio access technology and terminology used. The radio network node 12 is comprised in a first radio access network (RAN1) of a first network.

Furthermore, the communication network 1 comprises a first core network (CN1) and a second core network (CN2). The radio network node 12 may communicate with both the CN1 and the CN2. The first network comprises the first core network CN1. The first network is a virtual network sliced into a number of network slices, the CN1 and/or the RAN1 may be a virtual network sliced into CN slices and/or RAN slices, each network slice or core network slice supports one or more type of wireless devices and/or one or more type of services i.e. each network slice supports a different set of functionalities. Network slicing introduces the possibility that the network slices are used for different services and use cases and these services and use cases may introduce differences in the functionality supported in the different network slices. Each network slice may comprise one or more network nodes or elements of network nodes providing the services/functionalities for the respective network slice. Each slice may comprise a network node such as a core network slice node or a RAN slice node. For example, a first network slice for e.g. MTC devices may comprise a first network slice node 13. A second network slice for e.g. MBB devices may comprise a second network slice node 14. Each network slice supports a set of functionalities out of a total set of functionalities in the communication network. E.g. the first network slice node 13 supports a first set of functionalities out of the total set of functionalities in the communication network 1. The first set of functionalities is separated from a different set of functionalities out of the total set of functionalities in the communication network 1. E.g. the first set of functionalities being associated with MTC devices is separated or logically separated, e.g. using separated data storage or processing resources, from a second set of functionalities of the second network slice being associated with MBB devices. The first set of functionalities may use one or more resources in a core or RAN network of the communication network, which one or more resources are separated from other resources used by a different set of functionalities, i.e. different network slices, out of the total set of functionalities in the communication network 1. The resources may then be dedicated or virtually dedicated for each set of functionalities or network slice. Thus, the network slice node may be separated from other network slice nodes supporting a second set of functionalities out of the total set of functionalities in the communication network. Separated meaning herein physically separated wherein the network slice nodes may be executed on different hardware platforms and therefore using different resources of the hardware, and/or logically separated wherein the network slice nodes may be executed on a same hardware platform and use different resources such as memory parts or resources of processor capacity but may also use some same resources of the hardware e.g. a single physical network slice node may be partitioned into multiple virtual network slice nodes.

Hence, the first network slice node 13 supports the first set of functionalities out of the total set of functionalities in the first network of the communication network, which first set of functionalities belongs to the first network slice of the first network, and is separated from another set of functionalities out of the total set of functionalities in the first network.

A first network comprises one or more first network nodes 15, such as first core network nodes 19 e.g. Radio Software Defined Networking (SDN) nodes, MMEs, S-GWs, Serving GPRS Support Nodes (SGSN), or corresponding nodes in e.g. a 5G network or similar. The GPRS meaning General Packet Radio Services. The first network node 15 may further be a radio access network node such as the first radio network node 12.

A second network comprises one or more second network nodes 18, such as second core network nodes 20 e.g. Radio SDN nodes, MMEs, S-GWs, SGSNs, or corresponding nodes in e.g. a 5G network or similar. The second network node 18 may further be a radio access network node such as the first radio network node 12.

When shared networks are introduced a problem occurs when multiple PLMNs, such as the first and the second network, are hosted in RAN and MMEC is not

coordinated between the PLMNs. As S-TMSI is generated independently by core network node instances, there will be a risk that in a paging message a unique UE cannot be pointed out by the MMEC included in the S-TMSI. If the MMEC for the first network node 19 and the second network node 20 are not coordinated, the CN1 may assign the same MMEC to the first network node 19 as the CN2 assigns the second network node 20.

Thereby the MMEC part of the S-TMSI would be identical between the nodes. Further, since the M-TMSI is randomly generated by each network node there is also a high possibility that the M-TMSI is identical for the first and second network nodes 19, 20. Hence, the radio network node will transmit an S-TMSI to the UEs in the RAN which does not uniquely identify a single UE. In the scenario described herein, the UE 10 may be paged by the first network node 19 with a S-TMSI. However, since paging request are transmitted to UEs using broadcasting all UEs comprised in the RAN will listen to the transmitted S-TMSI. If the second UE 10' has been identified with an identical M-TMSI by the second network node 20, which has an identical MMEC as the first network node 19 the second UE 10' will listen to the S-TMSI and determine that the transmitted S-TMSI is intended for the second UE 10'. The second UE 10' will therefore try to send an erroneous paging response to the CN2. Further, when the first radio network node 12 receives the paging response it will not know if the response is intended for the first network node 19 or the second network node 20 and may also forward the message to the wrong CN node.

If slicing is introduced and simultaneous registration at multiple slices is supported for a given wireless device 10, then paging may originate from one of the multiplicity of slices that the wireless device 10 is registered with. In case where a single core network node can support multiple slices, the S-TMSI included in the paging message that includes a single MMEC identifying a single core network node 19 will not be enough for the wireless device 10 to identify the specific slice in the core network node 19 that issued the paging message.

If the slice identifiers are not coordinated between core networks within the communication network 1 supporting multiple slices it may not be possible to identify from the identities in a service request message, such as e.g. a paging message, which slice the paging request concerns. The latter may generate a number of problems such as e.g. erroneous service request from the wireless device to a wrong slice as response to a reception of a paging message.

Embodiments herein therefore provide a cost effective and easy way of identifying an intended sending and/or a receiving logical node in a communications network comprising a plurality of networks, such as PLMNs, that is simple and feasible from an implementation perspective, e.g. only enhancement on existing interfaces and network functions.

By minimizing the coordination of different identifiers, such as e.g. MMEC and slice ID, between PLMNs when multiple PLMNs are hosted in the same RAN the number of cross-PLMN configurations can be reduced which saves costs of running such networks.

Furthermore, if the PLMNs comprise multiple network slices and multiple slices are configured in a core network node, some of the embodiments described herein enable routing of a NAS message to the NAS instance associated with the slice instance in the network that triggered paging, when a paging message is received by the wireless device. The embodiments herein, enable a correct identification of logical nodes during service request initiated by either the wireless device or by the core network node, by using not only S-TMSI but also a network ID for identification of the logical nodes. Thereby the dependencies of MMEC and/or slice ID between PLMNs are removed. Hence, by minimizing the coordination of identifiers across different PLMNs, the number of cross- PLMN configurations may be reduced which saves costs of running such networks.

A first aspect of embodiments herein therefore relate to a Network Initiated Service Request procedure, which may also be referred to as paging, for enabling connection setup for a wireless device 10 in the communication network 1.

When a wireless device 10 is attached to a network, which may be referred to as

EMM REGISTERED, it may enter RRC IDLE (ECM IDLE) mode, due to e.g. inactivity.

The core network can initiate a Network Initiated Service Request by transmitting a paging message to the wireless device 10 through S1AP and RRC protocols and related signalling. According to current 3GPP standards S-TMSI, which comprises the MMEC for identifying a core network node and the M-TMSI for identifying a wireless device, is used as an identifier for the wireless device 10 and the core network node 19 in paging and service request procedures. The S-TMSI consists of MMEC for identifying the core network node 19 and the M-TMSI generated by the core network node 19 for identifying the wireless device 10. However, this requires that the MMEC and the M-TMSI have to be coordinated between different networks.

The paging procedure according to embodiments described herein is shown in

FIG. 10, where the identifiers introduced in the embodiments herein are indicated with bold font. The Network Initiated Service Request according to embodiments herein comprises the following actions:

Action 1001 : The core network node 19 transmits a paging message over the S1 interface to the RAN node 12. The paging message comprises a network ID, such as a

PLMN-ID, for the network which is sending the paging message and a S-TMSI, which S- TMSI comprises the MMEC for the core network node 19 sending the paging request and the M-TMSI generated by the core network node 19 for identifying the wireless device 10. When the core network node 19 is serving several slices, the paging message may further comprise a slice identification, such as a slice ID, of the network slice transmitting the paging message.

Action 1002: The RAN node 12 forwards the paging message to the wireless device 10 over the RRC connection. The paging message is broadcasted in the RAN which allows all wireless devices located in the RAN to listen to the message.

Action 1003: The wireless device 10 may determine that it is the intended receiver of the paging message based on the network ID, such as the PLMN-ID, and the MMEC and M-TMSI comprised in the S-TMSI.

Action 1004: The wireless device 10 may respond to the paging message by sending a RRC paging response to the RAN node 12. The response comprises the received PLMN-ID of the network paging the wireless device 10, the S-TMSI indicating the MMEC of the core network node 19 paging the wireless device 10 and a NAS- Protocol Data Unit (PDU). When the core network node 19 is serving several slices, the response message may further comprise the slice identification, such as the slice ID, of the network slice transmitting the paging message.

The different identifiers may be transmitted to the RAN node 12 in one single message or may be transmitted in a plurality of messages, such as e.g. transmitting the S-TMSI in a RRC Connection Request message and the PLMN-ID, the slice ID and the NAS-PDU in a RRC Connection Setup Complete message.

Action 1005: The RAN node 12 may determine the receiving core network node based on the network ID and the core network node ID received in the paging response from the wireless device 10.

Action 1006: The RAN node 12 may further transmit an initial setup message, such as a S1AP Initial UE message, to the determined core network node 19. The initial setup message comprises the S-TMSI and the NAS-PDU. When the core network node 19 is serving several slices, the response message may further comprise the slice identification, such as the slice ID, of the network slice transmitting the paging message.

Action 1007: The core network node 19 may identify a specific wireless device

10 instance based on the M-TMSI. When the core network node 19 is serving several slices, the core network node 19 may further identify a specific wireless device 10 slice instance based on the M-TMSI and the slide ID indicated in the initial setup message received from the RAN node. Hence, if the RAN is hosting multiple PLMNs, current 3GPP standards require that the MMECs are coordinated between the participating PLMNs in the RAN for avoiding false paging, since the S-TMSI is generated independently between the core network node instances. If the MMECs would not be coordinated between networks, there would be a risk that core network nodes in different networks would have the same MMEC.

Further, there is a possibility that these two core network nodes generate the same M- TMSI which would lead to a duplicate S-TMSI in the communication network. Since MMECs are not necessarily coordinated across different PLMNs, a paging message only comprising an S-TMSI would not be able to unequivocally be associated to one wireless device 10 only.

In this embodiment the method is therefore enhanced to enable a correct delivery of paging messages for uncoordinated MMECs. An un-coordination of MMECs implies that there could be more than one wireless device 10 with the same S-TMSI. To avoid this, a PLMN ID for the network to which the paged wireless device 10 is attached to is added to the paging message.

In a further embodiment herein, there may be more than one slice configured on a given CN node. This means that in case where multiple slices are configured on a single CN node and where paging can be triggered by any of such slices, the PLMN ID and the S-TMSI will not be sufficient to provide information about which slice has triggered the paging when the paging message is received by the wireless device 10. If the wireless device 10 has a NAS entity per slice to which it is registered, the lack of the slice identifier (Slice ID) makes it impossible for the AS layer to inform the right NAS entity about the paging. In general if a slice ID is missing in the paging message the wireless device 10 would not be able to derive the Slice ID for which a service request is needed, following a paging request. Therefore, in a further embodiment the paging message may further contain a Slice ID.

In a scenario where a core network node 19, such as e.g. an MME, which is identified by a single MMEC, is serving multiple slices, there is a need to specify which partition of the core network node 19 the paging message is originated from. Since the core network node 19 may use the same M-TMSI for both slices, an indication of the slice sending the paging message may be included. Since the correct core network itself is identified by the MMEC code and the network ID, it is sufficient to only coordinate the slice ID within each core network node. Hence, the slice ID may be reused in the

communications network as long as they are unique within each core network node 19. In order to maintain the backward compatibility with legacy wireless device 10, where only S-TMSI is used as paging identifier, the MMEC range may be divided into two parts, where one part is used for legacy wireless devices, where the MMEC in this range needs to be coordinated between participating PLMNs in RAN network, and the second 5 part of MMEC range is used by wireless device type supporting shared RAN, paged according to the methods above, where MMEC coordination is not required.

The method actions performed by the RAN node 12, for enabling connection setup for the wireless device 10 in the communication network 1 according to embodiments

10 herein will now be described with reference to a flowchart depicted in Fig. 11. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes. The

communication network 1 comprises the first network and the second network. The RAN node 12 is associated with the first and the second network. The first core network node

15 19 is associated with the first network and a second core network node 20 is associated with the second network. In some embodiments herein, the first network may further comprise partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10, and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first

20 network.

Action 1101 : The RAN node 12 receives a paging request from a core network node 19. The paging request comprises an indication of a network identity, such as e.g. a PLMN-ID, for the network associated with the core network node 19, a core network node IDentity (ID), such as a MMEC, associated with the core network node 19 and a wireless 25 device identity, such as S-TMSI or a M-TMSI, of the wireless device 10 which is being paged.

If the first network comprises partitioned sets of functionalities belonging to network slices of the first network, the paging request may further comprise an indication of the first network slice supporting the wireless device 10. The indication may indicate

30 that the first network slice of the core network node 19 is paging the wireless device 10.

By adding an indication of the network slice, paging originating from different slices managed by a single core network node, such as a MME, can be uniquely identified in the paging message. Furthermore, if multiple slices are configured in the core network node 19, embodiments herein enable routing of a NAS message to the NAS instance

35 associated with the slice instance in the network that triggered paging at reception of the paging message in the wireless device 10. Hence it enables identification of a wireless device during a paging procedure, using not only S-TMSI but also PLMN-ID and slice ID as a combination of parameters for correct identification of CN nodes and wireless device. Thereby, the dependencies of MMEC and slice ID between PLMN can be removed, which reduces the amount of coordination between the networks in the communication network 1.

The combination of the parameters <PLMN ID> <S-TMSI> <Slice ID> allows the RAN node 12 to unequivocally identify a single network device and the slice for which the UE is paged, since the S-TMSI and optionally the Slice ID are unique within a PLMN ID.

The paging request may be received from the core network node over the S1 interface.

In order to maintain the backward compatibility with legacy wireless devices, which only use S-TMSI as paging identifier, the MMEC range may be divided into two parts. A first part may be used for legacy wireless devices, wherein the MMEC in this first part of the range is coordinated between participating networks, such as PLMNs in the RAN network. A second part of the MMEC range is used by new wireless device types, which may be paged according to the methods above, where a coordination of MMEC is not required between participating networks. Thereby an implementation of the method according to embodiments herein is possible in existing networks supporting legacy wireless devices.

This action 1 101 is similar to the action 1001 described above in relation to Fig. 10. Action 1102: The RAN node 12 transmits the paging request to the wireless device 10 associated with the wireless device identity, such as S-TMSI. The paging request is transmitted as a broadcasted message in the RAN, thereby every wireless device 10 in the RAN may listen to the paging request. The paging request however, indicates the network identity for the network associated with the core network node, the core network node ID associated with the core network node, and the wireless device identity. Based on the network identity, the core network node ID and the wireless device ID the wireless device 10 may determine that it is the intended receiver of the paging request. Thereby only the wireless device 10 camping on the network identified by the network ID in the paging message, and associated to the wireless device identity, such as an S-TMSI, in the paging message will respond to the paging message.

If the first network comprises partitioned sets of functionalities, the paging request may further comprise an indication of the first network slice paging the wireless device. Such an indication may also be referred to as a slice ID. The indication may indicate that the first network slice of the core network node 19 is paging the wireless device 10. By including the slice ID the wireless device 10 will know that it has been paged for a specific slice ID of the network, hence it may perform a page response for the Slice ID indicated in the paging message.

The RAN node 12 may transmit the paging request to the wireless device 10 using a RRC protocol.

This action 1 102 is similar to the action 1002 described above in relation to Fig. 10.

Action 1103: The RAN node 12 may receive a response from the wireless device 10, which response comprises the network ID of the first network selected for

communication with the wireless device 10, the core network node ID for the core network node associated with the selected network and a wireless device identity of the wireless device 10 which is being paged. When the wireless device had been paged, the network selected for communication is the network which has sent the paging request.

When the first network comprises partitioned sets of functionalities, the response may further comprise an indication of the first network slice paging the wireless device. Thereby the wireless device can indicate which network slice the response is directed to.

The response may be a connection request such as a RRC Connection

Establishment Request and/or a RRC Connection Setup Complete message.

This action 1 103 is similar to the action 1004 described above in relation to Fig. 10. Action 1104: The RAN node 12 may determine, which may also be referred to as identify, a core network node based on the received network ID and the received core network node ID from the wireless device 10. Since the core network node ID is unique for each core network node within each network ID, the RAN node 12 will be able to unequivocally identify an intended receiving core network node for the response received from the wireless device 10.

This action 1104 corresponds to the action 1005 described above in relation to Fig.

10.

Action 1105: The RAN node 12 may transmit an initial setup message for the wireless device 10 to the determined core network node. The initial setup message comprises the wireless device identity of the wireless device 10 which is being paged. If the first network comprises partitioned sets of functionalities the initial setup message may further comprises an indication of the network slice paging the wireless device 10.

The method actions performed by the first core network node 19 for enabling connection setup for a wireless device 10 in a communication network 1 according to embodiments herein will now be described with reference to a flowchart depicted in Fig. 12. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes. The communication network 1 comprises a first network and a second network, which first core network node 19 is associated with the first network and wherein a second core network node 19 is associated with the second network. The first core network node 19 is being identified by a first core network node IDentity, ID, and the second core network node is being identified by a second core network node ID. The first and the second core network node IDs are uncoordinated between the first network and the second network. According to some embodiments herein, the first network may further comprise partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10. The first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network. The core network node may further comprise partitioned sets of functionalities wherein a first set of functionalities belongs to the first network slice.

Action 1201 : The core network node 19 initiates a connection establishment for the wireless device 10 by transmitting a paging request to the RAN node 12. The paging request comprises an indication of a network identity for the first network associated with the core network node 19, the core network node ID and a wireless device identity of the wireless device 10 which is being paged by the core network node.

When the first network comprises partitioned sets of functionalities, the paging request may further indicate the first network slice paging the wireless device 10. This indication indicates which network slice of the core network node is paging the wireless device.

The paging request may be transmitted to the RAN node 12 over the S1 interface.

In order to maintain the backward compatibility with legacy wireless devices, which only use S-TMSI as paging identifier, the MMEC range comprised in the S-TMSI may be divided into two parts. A first part may be used for legacy wireless devices, wherein the MMEC in this first part of the range is coordinated between participating networks, such as PLMNs in the RAN network. A second part of the MMEC range is used by new wireless device types, which may be paged according to the methods above, where a coordination of MMEC is not required between participating networks. Thereby an implementation of the method according to embodiments herein is possible in existing networks supporting legacy wireless devices.

This action 1201 is similar to the action 1001 described above in relation to Fig. 10. Action 1202: The core network node 19 may receive an initial setup message for the wireless device 10 from the RAN node 12. The initial setup message may comprise a wireless device identity of the wireless device 10 which is being paged and an indication of the network slice paging the wireless device 10.

This action 1202 is similar to the action 1006 described above in relation to Fig. 10.

Action 1203: The core network node 19 may identify a specific wireless device instance based on the received wireless device identity and the received network slice indication.

This action 1203 is similar to the action 1007 described above in relation to Fig. 10.

The method actions performed by the wireless device 10, for establishing a connection to a communication network 1 according to embodiments herein will now be described with reference to a flowchart depicted in Fig. 13. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes. The communication network 1 comprises a first network and a second network. The first network is associated with a first core network node 19 and the second network is associated with a second core network node 20. The first and the second networks are further associated to the RAN node 12.

In some embodiments herein, the first network may further comprise partitioned sets of functionalities, wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10. The first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network.

In some embodiments herein, the wireless device 10 may further comprise partitioned sets of functionalities. A first set of functionalities may belong to the first network slice supporting the wireless device 10 and a second set of functionalities may belong to a second network slice supporting the wireless device 10, wherein the first set of functionalities is separated from the second set of functionalities in the wireless device 10.

Action 1301 : The wireless device receives a paging request from the RAN node

12. The paging request is transmitted as a broadcasted message in the RAN, thereby every wireless device 10 in the RAN may listen to the paging request. The paging request comprises an indication of a network identity, ID, of the network associated with the core network node 19 transmitting the paging request, a core network node ID identifying the first core network node 19 and the wireless device identity of the wireless device 10. This allows the wireless device 10 to identify the network and the core network node 19 in the network which has transmitted the paging request.

When the first network comprises partitioned sets of functionalities each belonging to a network slice, the paging request may further indicate the first network slice paging the wireless device 10.

This action 1301 is similar to the action 1002 described above in relation to Fig. 10.

Action 1302: The wireless device 10 may determine that the wireless device is the intended receiver of the paging message based on the received network ID of the network associated with the core network node 19 transmitting the paging request, a core network node ID identifying the first core network node 19 and the wireless device identity.

This action 1302 corresponds to the action 1003 described above in relation to Fig.

10.

Action 1303: The wireless device 10 may further determine, when the wireless device and the network comprise partitioned sets of functionalities, the first set of functionalities belonging to the first network slice indicated in the paging request, based on the indication of the network slice.

Action 1304: The wireless device 10 may further forward the paging request to the determined set of functionalities in the wireless device 10.

Action 1305: The wireless device 10 transmits a response to the RAN node 12. The response comprises the network ID of the first network indicated in the paging request, the core network node ID for the core network node 19 indicated in the paging request and the wireless device identity of the wireless device 10. By including the network ID as well as the core network ID in the response, the RAN node 12 is able to determine which core network node 19 is the receiving node for the response, even if two core network nodes 19, 20 in two separate networks would have the same core network node ID.

When the wireless device 10 comprises partitioned sets of functionalities, the transmitting may be initiated by the determined set of functionalities belonging to the first network slice indicated in the paging request.

When the first network comprises partitioned sets of functionalities each belonging to a network slice, the response may further comprise an indication of the network slice paging the wireless device, which allows the receiving core network node 19 to determine which network slice, i.e. which set of functionalities in the core network node 19 the wireless device 10 shall be connected to. The response may be a connection request such as a RRC Connection

Establishment Request and/or a RRC Connection Setup Complete message transmitted via the RRC protocol.

This action 1305 is similar to the action 1004 described above in relation to Fig. 10.

A similar scenario as described above may occur when the wireless device initiates a service request procedure. The wireless device is attached to a core network node but has entered RRC IDLE, due to e.g. inactivity. In order to request service on the core network from this state, the wireless device 10 will initiate a RRC Connection

Establishment procedure. During this procedure the wireless device will send a request to the RAN node comprising an indication of the core network node which it is attached to. According to current standard the wireless device 10 will indicate the core network node by sending the S-TMSI to the RAN node 12. If the MMECs for core network nodes in different networks, such as PLMNs, hosted by the RAN are uncoordinated, the RAN node may not be able to identify the correct core network node 12. For the same reason in case where a single core network node can support multiple slices, the S-TMSI included in a RRCConnectionRequest message, that includes a single MMEC identifying a single core network node can't be used to identify a specific slice in the core network node.

Hence a second aspect of embodiments herein relate to a Service Request procedure initiated by the wireless device 10. In particular, it relates to CN node selection and wireless device 10 slice instance identification performed during service request.

During the service request, the wireless device 10 indicates a network, a core network node and a network slice for which a service request, or in general for which attachment to the network, is to be initiated. This indication may be performed as part of an RRC connection establishment procedure. The wireless device may indicate the network based on a PLMN-ID, the core network node based on S-TMSI comprising MMEC, and the network slice based on a slice ID. The receiving core network node may be identified by other nodes, such as the RAN node 12, based on PLMN-ID and MMEC information.

Addressing of the right MME is therefore achieved by ensuring a coordination of MMECs of MMEs supporting slices within a PLMN. MMECs can be reused across PLMNs but are unique within a single PLMN. Therefore, determining the core network node to which NAS PDUs are to be forwarded, based on PLMN ID and MMEC ensures unequivocal routing of the service request. The service request procedure according to embodiments described herein is shown in Fig. 14, where the identifiers introduced in the embodiments herein are indicated with bold font. The Service Request initiated by the wireless device 10 comprises the following actions:

Action 1401 : The RAN node may transmit a System Information Block 1 (SIB1) message to the wireless device 10, comprising an indication of the supported PLMN-IDs, a Tracking Area Code (TAC) and a Closed Subscriber Group (CSG) for assisting the wireless device 10 in evaluating a cell access.

Action 1402: The wireless device 10 initiates the setup request by transmitting a RRC Connection Request (RRCConnReq) to the RAN node 12 comprising S-TMSI and the reason for the setup request.

Action 1403: The RAN node 12 may transmit a RRC Connection Setup

(RRCConnSetup) message to the wireless device 10 in response to the RRC Connection Request, which may comprise an indication of a configuration used for the connection with the wireless device 10.

Action 1404: The wireless device 10 transmits a RRC Connection Setup

Complete (RRCConnSetupComp) message to the RAN node 12 comprising an indication of the selected network, such as a PLMN-ID, an indication of the network slice, such as a slice ID, supporting the wireless device 10 in the selected network and the NAS-PDU.

Action 1405: The RAN node 12 may determine the receiving core network node 19 based on the selected network ID, such as the PLMN-ID, and the core network node ID, such as the MMEC, comprised in the S-TMSI received from the wireless device 10.

Action 1406: The RAN node 12 may transmits an initial setup message, such as a S1AP Initial UE message, to the determined core network node 19. The initial setup message comprises the S-TMSI, the slice identification, such as the slice ID, of the network slice supporting the wireless device 10 in the selected network and the NAS-PDU.

Action 1407: The core network node 19 identifies a specific wireless device 10 slice instance based on the M-TMSI comprised in the S-TMSI and the slide ID indicated in the initial setup message received from the RAN node.

The method actions performed by the wireless device 10, for establishing a connection to the communication network 1 according to embodiments herein will now be described with reference to a flowchart depicted in Fig. 15. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes. The communication network 1 comprises a first network and a second network, which first network is associated with a first core network node and which second network is associated with a second core network node. The first and the second network are further associated to a Radio Access Network (RAN) node 12. The first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10. The first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network.

Action 1501 : The wireless device 10 initiates a connection establishment by transmitting a service request to the RAN node 12. The service request comprises a network ID, such as a PLMN-ID, of the first network associated with the first network slice, a core network node ID, such as a MMEC, for the core network node associated with the first network slice, a wireless device ID, such as a S-TMSI or M-TMSI, of the wireless device and an indication of the network slice, such as a slice ID, to which the wireless device is initiating the connection establishment.

In some embodiments herein the wireless device 10 may comprise partitioned sets of functionalities, wherein a first set of functionalities belongs to the first network slice supporting the wireless device 10 and a second set of functionalities belongs to a second network slice supporting the wireless device 10. The first set of functionalities may be separated from the second set of functionalities in the wireless device 10. When the wireless device comprises partitioned set of functionalities the initiating of the connection establishment may be initiated, which may also be referred to as performed, by the first set of functionalities of the wireless device 10.

The initiating may be performed over the RRC protocol as part of a RRC

Connection Setup procedure.

This action 1501 is similar to the actions 1402 and 1404 described above in relation to Fig. 14.

The method actions performed by the Radio Access Network (RAN) node 12, for enabling connection setup for the wireless device 10 to the communication network 1 according to embodiments herein will now be described with reference to a flowchart depicted in Fig. 16. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes. The communication network 1 comprises a first network and a second network, which RAN node 12 is associated with the first and the second network. A first core network node 19 is associated with the first network and a second core network node 20 is associated with the second network. The first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10, and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network.

Action 1601 : The RAN node 12 receives a service request or a paging response from the wireless device 10. The service request comprises a network ID, such as a PLMN-ID of the first network associated with a first network slice supporting the wireless device 10, a core network node ID, such as a MMEC, for the core network node associated with the first network slice, a wireless device ID, such as a M-TMSI, of the wireless device 10 and an indication of the network slice supporting the wireless device 10, such as a slice ID.

This action 1601 is similar to the actions 1402 and 1404 described above in relation to Fig. 14.

Action 1602: The RAN node 12 determines a core network node based on the received network ID and the received core network node ID. Since the core network IDs are unique within each network and the RAN node 12 can determine the correct network based on the network ID the correct core network node can be determined without having to coordinate the core network node IDs between networks. Thereby an unequivocal routing of the service request can be performed.

This action 1602 corresponds to the action 1405 described above in relation to Fig.

14.

Action 1603: The RAN node 12 transmits an initial setup message for the wireless device 12 to the determined core network node. The initial setup message comprises an indication of a wireless device ID of the wireless device 10 and an indication of the network slice supporting the wireless device 10. Based on the indication of the wireless device ID and the indication of the network slice, such as a slice ID, the core network node 19 can, when the core network node comprises partitioned sets of functionalities, determine the set of functionalities of the core network node responsible for the

communication with the wireless device 10.

This action 1603 is similar to the action 1406 described above in relation to Fig. 14. The method actions performed by the first core network node 19, for enabling connection setup for the wireless device 10 to the communication network 1 according to embodiments herein will now be described with reference to a flowchart depicted in Fig. 17. The actions do not have to be taken in the order stated below, but may be taken in any suitable order. Actions performed in some embodiments are marked with dashed boxes. The communication network 1 comprises a first network and a second network, which first core network node 19 is associated with the first network and wherein a second core network node 20 is associated with the second network. The first core network node is being identified by a first core network node IDentity, ID, and the second core network node is being identified by a second core network node ID. The first and the second core 5 network node IDs are uncoordinated between the first network and the second network. The first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10, and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network.

10 Action 1701 : The core network node 19 receives an initial setup message for the wireless device 10 from the RAN node 12. The initial setup message comprises a wireless device identity of the wireless device 10 performing the setup request and an indication of the network slice supporting the wireless device 10.

The wireless device identity may be a S-TMSI or a M-TMSI and the indication of

15 the network slice may be a slice ID.

The initial setup message may be received from the RAN node 12 over the S1 interface.

This action 1701 is similar to the action 1406 described above in relation to Fig. 14. Action 1702: The core network node identifies a specific wireless device instance, 20 which identification is based on the received wireless device identity and the network slice indication.

The identification of the wireless device instance may comprise determining a set of functionalities belonging to the received indication of the network slice supporting the wireless device.

25 The identification of the wireless device instance may further comprise forwarding the initial setup message to the determined set of functionalities in the core network node for enabling a connection between the wireless device 10 and the set of functionalities in the core network node supporting the wireless device 10.

This action 1702 corresponds to the action 1407 described above in relation to Fig.

30 14.

Fig. 18 is a block diagram depicting the RAN node 12 for enabling connection setup for the wireless device 10 in the communication network 1. The communication network 1 comprises the first network and the second network, which RAN node 12 is associated with the first and the second network. A first core network node 19 is

35 associated with the first network and a second core network node 20 is associated with the second network. The first network may further comprise partitioned sets of functionalities, wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10, and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network. The RAN node 12 may comprise a processing unit 1801 , e.g. one or more processors, configured to perform the methods described herein.

The RAN node 12 is configured to, e.g. by means of a receiving module 1802 and/or the processing unit 1801 being configured to, receive a paging request from a core network node 19, which paging request comprises an indication of a network identity for the network associated with the core network node 19, a core network node ID associated with the core network node 19 and a wireless device identity of the wireless device 10 which is being paged. The RAN node 12 may further be configured to, e.g. by means of the receiving module 1802 and/or the processing unit 1801 being configured to, receive the paging request further comprising an indication of the first network slice supporting the wireless device 10, wherein the indication is indicating that the first network slice is paging the wireless device 10.

The RAN node 12 is configured to, e.g. by means of a transmitting module 1803 and/or the processing unit 1801 being configured to, transmit the paging request to the wireless device 10 associated to the wireless device ID, which paging request indicates the network ID for the network associated with the core network node 19, the core network node ID associated with the core network node 19, and the wireless device ID. The RAN node may further be configured to, e.g. by means of a transmitting module 1803 and/or the processing unit 1801 being configured to, transmit the paging request as a broadcasted message in the RAN.

The RAN node 12 may further be configured to, e.g. by means of the receiving module 1802 and/or the processing unit 1801 being configured to, receive a response from the wireless device 10, which response comprises the network ID of the first network selected for communication with the wireless device 10, the core network node ID for the core network node 19 associated with the selected network and the wireless device ID of the wireless device 10. The response may further comprise an indication of the first network slice supporting the wireless device 10.

The RAN node 12 may further be configured to, e.g. by means of the receiving module 1802 and/or the processing unit 1801 being configured to, receive a service request from the wireless device 10, which service request comprises the network ID of the first network selected for communication with the wireless device 10, the core network node ID for the core network node 19 associated with the selected network and the wireless device ID of the wireless device 10.

The RAN node 12 may further be configured to, e.g. by means of a determining module 1804 and/or the processing unit 1801 being configured to, determine a core network node 19 based on the received network ID and the received core network node ID.

The RAN node 12 may further be configured to, e.g. by means of the transmitting module 1803 and/or the processing unit 1801 being configured to, transmit an initial setup message for the wireless device 10 to the determined core network node 19, which initial setup message comprises the wireless device identity of the wireless device 10 transmitting the response to the paging request and/or the wireless device 10 transmitting the service request. The initial setup message may further comprise an indication of the network slice supporting the wireless device 10.

The RAN node 12 further comprises a memory 1805. The memory comprises one or more units to be used to store data on, such as network slice information, wireless device IDs, network slice and roaming policies, Slice IDs applications to perform the methods disclosed herein when being executed, and similar.

The methods according to the embodiments described herein for the RAN node 12 are respectively implemented by means of e.g. a computer program 1806 or a computer program product, comprising instructions, i.e., software code portions, which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the RAN node 12. The computer program 1806 may be stored on a computer-readable storage medium 1807, e.g. a disc or similar. The computer-readable storage medium 1807, having stored thereon the computer program, may comprise the instructions which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the RAN node 12. In some embodiments, the computer-readable storage medium may be a non-transitory computer-readable storage medium.

Fig. 19 is a block diagram depicting the core network node 19 for enabling connection setup for the wireless device 10 in the communication network 1. The communication network 1 comprises a first network and a second network, which first core network node 19 is associated with the first network and wherein a second core network node 20 is associated with the second network. The first core network node 19 is being identified by a first core network node ID and the second core network node 20 is being identified by a second core network node ID, wherein the first and the second core network node IDs are uncoordinated between the first network and the second network. The first network may further comprise partitioned sets of functionalities wherein a first set 5 of functionalities belongs to a first network slice supporting the wireless device 10, and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network. The core network node 19 may comprise a processing unit 1901 , e.g. one or more processors, configured to perform the methods described herein.

10 The core network node 19 is configured to, e.g. by means of an initiating module

1902 and/or a transmitting module 1903 and/or the processing unit 1901 being configured to, initiate a connection establishment for the wireless device 10 by

transmitting a paging request to a RAN node 12, which paging request comprises an indication of a network identity for the first network associated with the core network node

15 19, the core network node ID and a wireless device identity of the wireless device 10 which is being paged. The paging request may further indicate the first network slice supporting the wireless device 10.

The core network node 19 may further be configured to, e.g. by means of an receiving module 1904 and/or the processing unit 1901 being configured to, receive an

20 initial setup message for the wireless device 10 from the RAN node 12, which initial setup message comprises a wireless device identity of the wireless device 10 which is being paged and an indication of the network slice supporting the wireless device 10.

The core network node 19 may further be configured to, e.g. by means of an identification module 1905 and/or the processing unit 1901 being configured to, identify

25 a specific wireless device instance, based on the received wireless device identity and the network slice indication.

The core network node 19 may further be configured to, e.g. by means of a determining module 1906 and/or the identification module 1904 and/or the processing unit 1901 being configured to, determining a set of functionalities in the core network node

30 belonging to the received network slice indication.

The core network node 19 may further be configured to, e.g. by means of a forwarding module 1907 and/or the identification module 1904 and/or the processing unit 1901 being configured to, forward the initial setup message to the determined set of functionalities. The core network node 19 further comprises a memory 1908. The memory comprises one or more units to be used to store data on, such as network slice

information, wireless device IDs, network slice and roaming policies, Slice IDs

applications to perform the methods disclosed herein when being executed, and similar.

The methods according to the embodiments described herein for the core network node 19 are respectively implemented by means of e.g. a computer program 1909 or a computer program product, comprising instructions, i.e., software code portions, which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the core network node 19. The computer program 1909 may be stored on a computer-readable storage medium 1910, e.g. a disc or similar. The computer-readable storage medium 1910, having stored thereon the computer program, may comprise the instructions which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the core network node 19. In some embodiments, the computer-readable storage medium may be a non-transitory computer-readable storage medium.

Fig. 20 is a block diagram depicting the wireless device 10 for establishing a connection to the communication network 1. The communication network comprises a first network and a second network, which first network is associated with a first core network node 19 and which second network is associated with a second core network node 20. The first and the second networks are further associated to a RAN node 12. The first network may further comprise partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device 10, and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network. The wireless device 10 may further comprise partitioned sets of functionalities wherein a first set of functionalities belongs to the first network slice supporting the wireless device 10 and a second set of functionalities belongs to a second network slice supporting the wireless device 10. The first set of functionalities is separated from the second set of functionalities in the wireless device 10. The wireless device 10 may comprise a processing unit 2001 , e.g. one or more processors, configured to perform the methods described herein.

The wireless device 10 is configured to, e.g. by means of a receiving module 2002 and/or the processing unit 2001 being configured to, receive a paging request from the RAN node 12, which paging request comprises an indication of a network ID of the network associated with the core network node 19, a core network node ID identifying the first core network node 19 and a wireless device identity of the wireless device 10. The paging request may further indicate the first network slice supporting the wireless device 10.

The wireless device 10 is configured to, e.g. by means of a transmitting module 5 2003 and/or the processing unit 2001 being configured to, transmit a response to the RAN node 12, which response comprises the network ID of the first network indicated in the paging request, the core network node ID for the core network node 19 indicated in the paging request and the wireless device identity of the wireless device 10. The wireless device 10 may further be configured to, e.g. by means of the transmitting module 2003

10 and/or the processing unit 2001 being configured to, transmit a service request to the RAN node 12, which service request comprises the network ID of the first network indicated in the paging request, the core network node ID for the core network node 19 indicated in the paging request and the wireless device identity of the wireless device 10. The response and/or the service request may further comprise an indication of the

15 network slice supporting the wireless device 10.

The wireless device 10 may further be configured to, e.g. by means of a determining module 2004 and/or the processing unit 2001 being configured to, determine that the wireless device 10 is the intended receiver of the paging message based on the received network ID of the network associated with the core network node

20 19 transmitting the paging request, a core network node ID identifying the first core

network node 19 and the wireless device identity.

The wireless device 10 may further be configured to, e.g. by means of a determining module 2004 and/or the processing unit 2001 being configured to, determining a set of functionalities, in the wireless device 10, belonging to the first

25 network slice indicated in the paging request, based on the indication of the network slice belonging to the received network slice indication.

The wireless device 10 may further be configured to, e.g. by means of a forwarding module 2005 and/or the processing unit 2001 being configured to, forward the paging request to the determined set of functionalities.

30 The wireless device 10 further comprises a memory 2006. The memory

comprises one or more units to be used to store data on, such as network slice information, wireless device IDs, network slice and roaming policies, Slice IDs

The methods according to the embodiments described herein for the wireless

35 device 10 are respectively implemented by means of e.g. a computer program 2007 or a computer program product, comprising instructions, i.e., software code portions, which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the wireless device 10. The computer program 2007 may be stored on a computer-readable storage medium 2008, e.g. a disc or similar. The computer-readable storage medium 2008, having stored thereon the computer program, may comprise the instructions which, when executed on at least one processor, cause the at least one processor to carry out the actions described herein, as performed by the wireless device 10. In some embodiments, the computer-readable storage medium may be a non-transitory computer-readable storage medium.

Embodiments herein relate to a network with network slices i.e. a (core or RAN or both) network with partitioned sets of functionalities wherein the core network node 19, the wireless device 10 and/or the RAN node 12 may support the first set of functionalities out of the total set of functionalities in the network of the communication network. The first set of functionalities belongs to the first network slice of the network, and is separated from another set of functionalities out of the total set of functionalities in the network.

As will be readily understood by those familiar with communications design, that functions means or modules may be implemented using digital logic and/or one or more microcontrollers, microprocessors, or other digital hardware. In some

embodiments, several or all of the various functions may be implemented together, such as in a single application-specific integrated circuit (ASIC), or in two or more separate devices with appropriate hardware and/or software interfaces between them. Several of the functions may be implemented on a processor shared with other functional components of a network node, for example.

Alternatively, several of the functional elements of the processing means discussed may be provided through the use of dedicated hardware, while others are provided with hardware for executing software, in association with the appropriate software or firmware. Thus, the term "processor" or "controller" as used herein does not exclusively refer to hardware capable of executing software and may implicitly include, without limitation, digital signal processor (DSP) hardware, read-only memory (ROM) for storing software, random-access memory for storing software and/or program or application data, and non-volatile memory. Other hardware, conventional and/or custom, may also be included. Designers of network nodes will appreciate the cost, performance, and maintenance trade-offs inherent in these design choices. It will be appreciated that the foregoing description and the accompanying drawings represent non-limiting examples of the methods and apparatus taught herein. As such, the apparatus and techniques taught herein are not limited by the foregoing description and accompanying drawings. Instead, the embodiments herein are limited only by the following claims and their legal equivalents.

Claims

A method performed by a Radio Access Network, RAN, node (12), for enabling connection setup for a wireless device 10 in a communication network (1), which communication network (1) comprises a first network and a second network, which RAN node (12) is associated with the first and the second network, wherein a first core network node (19) is associated with the first network and a second core network node (20) is associated with the second network, the method comprising:

- receiving (1001) a paging request from a core network node (19), which paging request comprises an indication of a network identity for the network associated with the core network node, a core network node IDentity, ID, associated with the core network node (19) and a wireless device identity of the wireless device (10) which is being paged;

- transmitting (1002) the paging request to the wireless device (10) associated to the wireless device identity, which paging request indicates the network identity for the network associated with the core network node (19), the core network node ID associated with the core network node (19), and the wireless device identity.

The method according to claim 1 , wherein the method further comprises:

- receiving (1003), a response from the wireless device (10), which response comprises the network ID of the first network selected for communication with the wireless device (10), the core network node ID for the core network node associated with the selected network and a wireless device identity of the wireless device (10) which is being paged;

- determining (1004) a core network node based on the received network ID and the received core network node ID,

- transmitting (1005), to the determined core network node (19), an initial setup message for the wireless device (10), which initial setup message comprises the wireless device identity of the wireless device (10) which is being paged.

The method according to claim 1 or 2, wherein the first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device (10), and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network; wherein

- the paging request further comprises an indication of the first network slice supporting the wireless device (10), wherein the indication is indicating that the first network slice is paging the wireless device (10).

The method according to claim 3, wherein:

- the response further comprises an indication of the first network slice

supporting the wireless device (10); and

- the initial setup message further comprises an indication of the network slice supporting the wireless device (10), wherein the indication is indicating that the first network slice is paging the wireless device (10).

A method performed by a first core network node (19), for enabling connection setup for a wireless device (10) in a communication network (1), which

communication network (1) comprises a first network and a second network, which first core network node (19) is associated with the first network and wherein a second core network node (20) is associated with the second network, wherein the first core network node (19) is being identified by a first core network node IDentity, ID, and the second core network node (20) is being identified by a second core network node ID, wherein the first and the second core network node IDs are uncoordinated between the first network and the second network, the method comprising:

- initiating (1101) a connection establishment for the wireless device (10) by transmitting a paging request to a Radio Access Network, RAN, node (12), which paging request comprises an indication of a network identity for the first network associated with the core network node (19), the core network node ID and a wireless device identity of the wireless device (10) which is being paged.

The method according to claim 5, wherein the first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to first network slice supporting the wireless device (10), and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network; wherein

- the paging request further indicates the first network slice paging the

wireless device (10).

The method according to claim 5 or 6, wherein the method further comprises:

- receiving (1 102), from the RAN node (12), an initial setup message for the wireless device (10), which initial setup message comprises a wireless device identity of the wireless device (10) which is being paged and an indication of the network slice paging the wireless device (10); and

- identifying (1 103) a specific wireless device instance, which identification is based on the received wireless device identity and the network slice indication.

A method performed by a wireless device (10), for establishing a connection to a communication network (1), which communication network (1) comprises a first network and a second network, which first network is associated with a first core network node (19) and which second network is associated with a second core network node (20), and which first and second network further are associated to a Radio Access Network, RAN, node (), the method comprising:

- receiving (1201) a paging request from the RAN node (12), which paging request comprises an indication of a network identity, ID, of the network associated with the core network node (19), a core network node ID identifying the first core network node (19) and the wireless device identity of the wireless device (10); and

- transmitting (1204), to the RAN node (12), a response, which response comprises the network ID of the first network indicated in the paging request, the core network node ID for the core network node (19) indicated in the paging request and the wireless device identity of the wireless device (10).

9. The method according to claim 8, wherein the first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device (10), and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network, wherein

- the paging request further indicates the first network slice paging the

wireless device (10); and

- the response further comprises an indication of the network slice paging the wireless device (10).

10. The method according to claim 8 or 9, wherein the wireless device (10) comprises partitioned sets of functionalities wherein a first set of functionalities belongs to the first network slice supporting the wireless device (10) and a second set of functionalities belongs to a second network slice supporting the wireless device (10), and wherein the first set of functionalities is separated from the second set of functionalities in the wireless device (10), the method further comprising:

- determining (1202) the first set of functionalities belonging to the first

network slice indicated in the paging request based on the indication of the network slice;

- forwarding (1203) the paging request to the determined set of

functionalities.

11. The method according to claim 10, wherein the transmitting (1204) is initiated by the determined set of functionalities.

12. A Radio Access Network, RAN, node (12) for enabling connection setup for a wireless device (10) in a communication network (1), which communication network (1) comprises a first network and a second network, which RAN node (12) is associated with the first and the second network, wherein a first core network node (19) is associated with the first network and a second core network node (20) is associated with the second network, the RAN node (12) being configured to:

- receive a paging request from a core network node (19), which paging request comprises an indication of a network identity for the network associated with the core network node (19), a core network node IDentity, ID, associated with the core network node (19) and a wireless device identity of the wireless device (10) which is being paged;

- transmit the paging request to the wireless device (10) associated to the wireless device identity, which paging request indicates the network identity for the network associated with the core network node (19), the core network node ID associated with the core network node (19), and the wireless device identity of the wireless device (10) which is being paged.

13. The RAN node (12) according to claim 12, wherein the RAN node further is

configured to:

- receive a response from the wireless device (10), which response

comprises the network ID of the first network selected for communication with the wireless device (10), the core network node ID for the core network node (19) associated with the selected network and a wireless device identity of the wireless device (10) which is being paged;

- determine a core network node (19) based on the received network ID and the received core network node ID,

- transmit, to the determined core network node (19), an initial setup

message for the wireless device (10), which initial setup message comprises the wireless device identity of the wireless device (10) which is being paged.

14. The RAN node (12) according to claim 12 or 13, wherein the first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device (10), and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network; wherein

- the paging request further comprises an indication of the first network slice paging the wireless device (10), wherein the indication is indicating that the first network slice is paging the wireless device (10).

15. The RAN node (12) according to claim 14, wherein:

- the response further comprises an indication of the first network slice paging the wireless device (10); and

- the initial setup message further comprises an indication of the network slice paging the wireless device (10).

16. A first core network node (19), for enabling connection setup for a wireless device (10) in a communication network (1), which communication network (1) comprises a first network and a second network, which first core network node (19) is associated with the first network and wherein a second core network node (20) is associated with the second network, wherein the first core network node (19) is being identified by a first core network node IDentity, ID, and the second core network node (20) is being identified by a second core network node ID, wherein the first and the second core network node IDs are uncoordinated between the first network and the second network, the core network node (19) being configured to:

- initiate a connection establishment for the wireless device (10) by

transmitting a paging request to a Radio Access Network, RAN, node (12), which paging request comprises an indication of a network identity for the first network associated with the core network node (19), the core network node ID and a wireless device identity of the wireless device (10) which is being paged.

17. The core network node (19) according to claim 16, wherein the first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device (10), and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network; wherein

- the paging request further indicates the first network slice paging the

wireless device (10);

18. The core network node (19) according to claim 16 or 17, wherein the core network node further is configured to:

- receive, from the RAN node (12), an initial setup message for the wireless device (10), which initial setup message comprises a wireless device identity of the wireless device (10) which is being paged and an indication of the network slice paging the wireless device (10); and

- identify a specific wireless device instance, based on the received wireless device identity and the network slice indication.

A wireless device (10), for establishing a connection to a communication network (1), which communication network (1) comprises a first network and a second network, which first network is associated with a first core network node (19) and which second network is associated with a second core network node (20), and which first and second network further is associated to a Radio Access Network, RAN, node (12), the wireless device (10) being configured to:

- receive a paging request from the RAN node (12), which paging request comprises an indication of a network identity, ID, of the network associated with the core network node (19), a core network node ID identifying the core network node (19) and a wireless device identity of the wireless device (10); and

- transmit, to the RAN node (12), a response, which response comprises the network ID of the first network indicated in the paging request, the core network node ID for the core network node (19) indicated in the paging request and the wireless device identity of the wireless device (10).

20. The wireless device (10) according to claim 19, wherein the first network further comprises partitioned sets of functionalities wherein a first set of functionalities belongs to a first network slice supporting the wireless device (10), and which first set of functionalities is separated from another set of functionalities out of a total set of functionalities in the first network, wherein

- the paging request further indicates the first network slice paging the

wireless device (10); and

21. The wireless device (10) according to claim 19 or 20, wherein the wireless device (10) comprises partitioned sets of functionalities wherein a first set of

functionalities belongs to the first network slice supporting the wireless device (10) and a second set of functionalities belongs to a second network slice supporting the wireless device (10), and wherein the first set of functionalities is separated from the second set of functionalities in the wireless device (10), the wireless device further being configured to:

- determine the first set of functionalities belonging to the first network slice indicated in the paging request based on the indication of the network slice;

- forward the paging request to the determined set of functionalities.

22. The wireless device (10) according to claim 21 , wherein wireless device (10) is further configured to initiate the transmitting by the determined set of functionalities.

23. A computer program comprising instructions, which, when executed on at least one processor, cause the at least one processor to carry out any of the methods according to any of the claims 1-1 1 , as performed by the core network node (19), the RAN node (12) or the wireless device (10).

24. A computer-readable storage medium, having stored thereon a computer program comprising instructions which, when executed on at least one processor, cause the at least one processor to carry out the method according to any of the claims 1-1 1 , as performed by the core network node (19), the RAN node (12) or the wireless device (10).