Patent Description:
Network slicing is a new concept that applies to both LTE Evolution and new <NUM> RAT (in this document called NR). The key driver for introducing network slicing is application expansion, i.e. improving the cellular operator's ability to serve other industries, e.g., by offering connectivity services with different network characteristics (performance, security, robustness, and complexity).

Network slicing in a network creates logically separated partitions of the network, addressing different applications. These "network slices" are logically separated to a degree that they can be regarded and managed as networks of their own. Network slices can be associated to different slice tenants, namely entities that provide services to the end used via the network slice. Example of slice tenants could be the armed forces, e.g. providing Voice services via a dedicated network slice; vehicles manufacturers, e.g. providing vehicle diagnostic services via a dedicated network slice; and more. It is also common to associate a Service Level Agreement (SLA) to each network slice. Such SLA indicates the treatment services provided within the network slice should be subject to.

A problem that has not been addressed is related to limited slice availability in the network. Limited slice availability may occur where a given network slice is not supported in all cells of the cellular network or not for all wireless devices/subscribers in all cells. In these cases problems will occur when the wireless is moving in or out of areas with different slice support. Problems will also occur when the wireless device is connecting to the network for the first time (or re-connecting) in case the slice the wireless device wants to connect to or is already registered in is not available in that area. Accordingly there is proposed herein several embodiments for handling limited slice availability in the network.

Additional background information can be found in Ericsson: "Radio interface implications of network slicing" 3GPP Draft; [NR] R2-<NUM>.

According to certain embodiments, a method is disclosed for use in a network node. The method comprises obtaining network slice availability associated with one or more neighboring network nodes. The network slice availability indicates which of a plurality of network slices is supported by each of the one or more neighboring network nodes. The method further comprises managing slice connectivity of a wireless device based on the network slice availability of the one or more neighboring network nodes. The method further comprises creating a paging area with consistent network slice availability for the wireless device, wherein the paging area comprises one or more of the neighboring network nodes that, based on the network slice availability, support a first network slice of the plurality of network slices, and communicating an indication of the paging area that supports the first network slice to the wireless device.

According to certain embodiments, a network node comprises storage operable to store instructions and processing circuitry operable to execute the instructions. The network node is operable to obtain network slice availability associated with one or more neighboring network nodes. The network slice availability indicates which of a plurality of network slices is supported by each of the one or more neighboring network nodes. The network node is further operable to manage slice connectivity of a wireless device based on the network slice availability of the one or more neighboring network nodes. The network node is further operable to create a paging area with consistent network slice availability for the wireless device, wherein the paging area comprises one or more of the neighboring network nodes that, based on the network slice availability, support a first network slice of the plurality of network slices, and to communicate an indication of the paging area that supports the first network slice to the wireless device.

According to certain embodiments, a computer program product comprises a non-transitory computer readable medium storing computer readable program code. The computer readable program code comprises program code for obtaining network slice availability associated with one or more neighboring network nodes. The network slice availability indicates which of a plurality of network slices is supported by each of the one or more neighboring network nodes. The computer readable program code further comprises program code for managing slice connectivity of a wireless device based on the network slice availability of the one or more neighboring network nodes. The computer readable program code further comprises code for creating a paging area with consistent network slice availability for the wireless device, wherein the paging area comprises one or more of the neighboring network nodes that, based on the network slice availability, support a first network slice of the plurality of network slices, and code for communicating an indication of the paging area that supports the first network slice to the wireless device.

The above-described method, network node, and/or computer program code may include various other features, including any one or more of the following:
In certain embodiments, each of the network slices comprises a respective logical network that supports a respective network function having different characteristics than the network functions of the other network slices.

In certain embodiments, each of the network slices supports a respective business operation that is independent of the business operations supported by the other network slices.

In certain embodiments, the one or more neighboring nodes comprise a plurality of core network nodes, and the method/wireless device/computer program product receives a slice identifier indicating which of the network slices the wireless device requests to use. The method/wireless device/computer program product further selects one of the core network nodes based on the network slice availability, wherein the selected core network node supports the network slice indicated by the slice identifier. The method/wireless device/computer program product further provides the wireless device with access to the selected core network node.

In certain embodiments, the one or more neighboring nodes comprise a plurality of radio network nodes, and the method/wireless device/computer program product manages the slice connectivity of the wireless device by determining which of the network slices the wireless device is connected to. The method/wireless device/computer program product further manages the slice connectivity of the wireless device by selecting one of the radio network nodes for handover based on the network slice availability. The selected radio network node supports the network slice(s) that the wireless device is connected to. The method/wireless device/computer program product further manages the slice connectivity of the wireless device by initiating handover of the wireless device to the selected radio network node.

In certain embodiments, the plurality of network slices comprises a first network slice and the method/wireless device/computer program product manages the slice connectivity of the wireless device by removing a connection between the wireless device and the first network slice in response to determining, based on the network slice availability, that the wireless device is connected to a radio access node that does not support the first network slice.

In certain embodiments, the plurality of network slices comprises a first network slice and the method/wireless device/computer program product manages the slice connectivity of the wireless device by adding a connection between the wireless device and the first network slice in response to determining, based on the network slice availability, that the wireless device is connected to a radio access node that supports the first network slice.

In certain embodiments, the plurality of network slices comprises a first network slice and the method/wireless device/computer program product manages the slice connectivity of the wireless device by rejecting a request to connect the wireless device to the first network slice in response to determining that the wireless device is connected to a radio access node that does not support the first network slice.

In certain embodiments, at least a portion of the network slice availability is obtained during an initial connection set up between the first network node and at least one of the neighboring network nodes.

In certain embodiments, at least a portion of the network slice availability is obtained from handover signaling between the first network node and one of the neighboring network nodes.

In certain embodiments, at least a portion of the network slice availability is obtained in response to the wireless device performing a state transition from an idle state to an active state.

In certain embodiments, the method/wireless device/computer program product maintains slice connection information at the first network node. The slice connection information indicating which of the network slices the wireless device is connected to. The method/wireless device/computer program also receives an indication that the wireless device has added or removed a connection to one of the network slices. The method/wireless device/computer program also updates the slice connection information maintained by the first network node based on the received indication.

In certain embodiments, method/wireless device/computer program, in response to determining that the wireless device has added or removed a connection to one of the network slices, creates a new paging area with consistent network slice availability for the wireless device. The method/wireless device/computer program also communicates the new paging area to the wireless device.

In certain embodiments, method/wireless device/computer program manages slice connectivity by initiating removal of a connection between the wireless device and a network slice that is unsupported by a neighboring network node selected for a handover procedure involving the wireless device.

In certain embodiments, the method/wireless device/computer program manages slice connectivity by receiving, from the wireless device, a request to connect to a first network slice. The method/wireless device/computer program further manages slice connectivity by rejecting the request and redirecting the wireless device to another network slice in response to determining that the first network node does not support the first network slice.

In certain embodiments, the method/wireless device/computer program manages the slice connectivity by receiving, from the wireless device, a request to connect to a first network slice. The method/wireless device/computer program further manages the slice connectivity by rejecting the request and redirecting the wireless device to another network slice based on a likelihood of the wireless device moving to a neighboring network node that does not support the first network slice.

In certain embodiments, the method/wireless device/computer program broadcasts a parameter associated with the network slice availability of the first network node and/or one or more of the neighboring network nodes.

In certain embodiments, method/wireless device/computer program communicates the first network node's network slice availability to one or more of the neighboring network nodes.

In certain embodiments, the network node is a core network node.

In certain embodiments, the network node is a radio network node.

According to certain embodiments, a method is disclosed for use in a wireless device. The method comprises receiving, from a network node, information associated with network slice availability in a network comprising the network node. The method further comprises communicating a connectivity request to the network node for access to a first network slice. The first network slice is selected by the wireless device based at least in part on the information associated with network slice availability received from the network node. The method further comprises receiving a paging area with consistent network slice availability for the wireless device, wherein the paging area comprises one or more neighboring network nodes that, based on network slice availability of the neighboring network nodes, support the first network slice; and preventing the generation of mobility signaling when the wireless device is within the paging area.

According to certain embodiments, a wireless device comprising storage operable to store instructions and a processor operable to execute the instructions. The wireless device is operable to receive, from a network node, information associated with network slice availability in a network comprising the network node. The wireless device is further operable to communicate a connectivity request to the network node for access to a first network slice. The first network slice is selected by the wireless device based at least in part on the information associated with network slice availability received from the network node.

The wireless device is further operable to receive a paging area with consistent network slice availability for the wireless device, wherein the paging area comprises one or more neighboring network nodes to the network node that, based on network slice availability of the neighboring network node, support the first network slice; and to prevent the generation of mobility signaling when the wireless device is within the paging area.

According to certain embodiments, a computer program product comprises a non-transitory computer readable medium storing computer readable program code. The computer readable program code comprises program code for receiving, from a network node, information associated with network slice availability in a network comprising the network node. The computer readable program code further comprises program code for communicating a connectivity request to the network node for access to a first network slice. The first network slice is selected by the wireless device based at least in part on the information associated with network slice availability received from the network node. The computer readable program code further comprises program code for receiving a paging area with consistent network slice availability for the wireless device, wherein the paging area comprises one or more neighboring network nodes that, based on network slice availability of the neighboring network nodes, support the first network slice; and program code for preventing the generation of mobility signaling when the wireless device is within the paging area.

The above-described method, wireless device, and/or computer program code may include various other features, including any one or more of the following:
In certain embodiments, at least a portion of the information associated with network slice availability is received in a broadcast from the network node.

In certain embodiments, at least a portion of the information associated with network slice availability is based on network configuration information received from the network prior to receiving the broadcast from the network node.

In certain embodiments, the method/wireless device/computer program initiates the setup of a network slice connection based on the information associated with network slice availability.

In certain embodiments, the method/wireless device/computer program initiates a removal of a network slice connection based on the information associated with network slice availability.

In certain embodiments, the method/wireless device/computer program performs reselection of one or more of a cell, a frequency, or a radio access technology based on the information associated with network slice availability.

In certain embodiments, the method/wireless device/computer program performs reselection by determining that a current cell, frequency, or radio access technology (RAT) on which the wireless device is operating does not support the first network slice. The method/wireless device/computer program performs reselection by further selecting a new cell, frequency, or RAT that supports the first network slice. The method/wireless device/computer program performs reselection by further accessing the first network slice through the new cell, frequency, or RAT.

In certain embodiments, the method/wireless device/computer program communicates a slice identifier indicating the first network slice. The method/wireless device/computer program further accesses a core network node that supports the first network slice indicated by the slice identifier.

In certain embodiments, the method/wireless device/computer program receives an initiation of a handover procedure to a second network node. The second network node supports the first network slice. The method/wireless device/computer program further completes handover to a second network node. The method/wireless device/computer program further accesses the first network slice through the second network node.

In certain embodiments, the method/wireless device/computer program communicates the information associated with network slice availability to another network node when performing a state transition from an idle state to an active state.

In certain embodiments, the method/wireless device/computer program receives a paging area with consistent network slice availability for the wireless device. The paging area comprises one or more neighboring network nodes to the network node that, based on network slice availability of the neighboring network node, support the first network slice. The method/wireless device/computer program further prevents the generation of mobility signaling when the wireless device is within the paging area.

In certain embodiments, the method/wireless device/computer program communicates area update signaling from the wireless device when the wireless device moves outside the received paging area. The method/wireless device/computer program further receives a new paging area with consistent network slice availability for the wireless device.

In certain embodiments, the method/wireless device/computer program communicates the wireless device's network slice connection information to the network node. The method/wireless device/computer program further receives handover signaling from the network node. The handover signaling comprises a handover candidate based on the network slice availability of neighboring network nodes and the network slice connection information of the wireless device. The method/wireless device/computer program further connects to the handover candidate.

In certain embodiments, the handover candidate does not support the first network slice, the method further comprising connecting to a second network slice.

Certain embodiments of the present disclosure may provide one or more technical advantages. For example, enhance connectivity of wireless devices to network slices in a network with limited network slice availability by managing the connectivity of the wireless device based on the network slice availability. As another example, certain embodiments may advantageously manage connectivity using a slice identifier indicating the network slices the wireless device requests to use. As yet another example, certain embodiments may advantageously create a paging area with consistent network slice availability for the wireless device. In this manner, when the wireless device moves within the paging area, the wireless device does not unnecessarily generate mobility signaling. As another example, certain embodiments may advantageously inform the wireless device when it is connected to a network slice. Other advantages may be readily apparent to one having skill in the art. Certain embodiments may have none, some, or all of the recited advantages.

The support for network slicing is an important part of the vision for the Next Generation architecture. As stated by different fora, such as Next Generation Mobile Networks, network slicing consists of deploying multiple end-to-end logical networks in support of independent business operations. In contrast to deploying an independent network infrastructure, each instance of a slice (blueprint) should be possible to realize as a logical network corresponding to a shared infrastructure (including shared processing, storage, transport, radio spectrum, and hardware platforms), where it co-exists with other slices having potentially different characteristics.

In this way, the infrastructure and assets utilization will be much more cost- and energy-efficient while the logical separation allows for a flexible and independent configuration and management of the slices without compromising stability and security. Enabling slice realization over a common physical infrastructure would of course not prevent the realization of a slice instance by means of dedicated resources and assets.

In 3GPP, the notion of network slicing has also been introduced as a way to address the needs for the different vertical industries, translated into a wide range of use cases for the Next Generation architecture. To give a few examples, <NPL>) explicitly states that a network slice should support the communication service requirements of particular use case(s). A set of service and operations requirements associated to network slicing has been provided. In 3GPP SA2, network slicing is presented as one of the high level architectural requirements and is listed as one of the key issues in order to enable the operator to create networks customised to provide optimized solutions for different market scenarios, which present diverse requirements. Example use cases for such customized logical networks could include public safety, V2X, Internet-of-Things (IoT), highlighting the importance of network slicing as a common platform to address multiple industries.

The support for network slicing is also listed as a requirement for the new RAT, as discussed in <NPL>). In order to fulfill that, one of the objectives listed in 3GPP SID Proposal RP-<NUM> is to study and identify specification impacts when enabling the realization of network slicing. Some initial studies have also been done within the research community. In RAN3 the following aspects have been captured for network slicing in TR <NUM>(the editor's notes have been removed):.

Network slicing is a new concept that applies to both LTE Evolution and new <NUM> RAT (in this document called NR). The key driver for introducing network slicing is business expansion, i.e. improving the cellular operator's ability to serve other industries, e.g., by offering connectivity services with different network characteristics (performance, security, robustness, and complexity).

The current working assumption is that there will be one shared Radio Access Network (RAN) infrastructure that will connect to several Core Network instances, such as Evolved Packet Core (EPC) instances (one EPC instance per network slice) or a further EPC evolution. As the CN functions (e.g. EPC functions) are being virtualized, it is assumed that the operator may instantiate a new Core Network (CN) when a new slice should be supported. In another case the network slices could be implemented based on existing monolithic EPC architecture based on special purpose hardware.

<FIG> illustrates an embodiment of a network <NUM> with network slices <NUM>, according to certain embodiments. Network <NUM> may comprise wireless devices <NUM>, radio access network (RAN) <NUM>, core network functions 130A and 130B, and network slices <NUM> (i.e. Slice <NUM> and Slice <NUM>). Wireless devices <NUM> may connect to one of network slices <NUM> through RAN <NUM> and one of core network functions 130A or 130B.

In certain embodiments, each of core network functions 130A or 130B may support a specific one of network slices <NUM>. For example, core network function 130A may support Slice <NUM> and core network function 130B may support Slice <NUM>, as illustrated in <FIG>. Wireless device <NUM> may connect to a particular one of network slices <NUM> by connecting through RAN <NUM> to a particular one or one of a group of core network functions <NUM> that support that particular one of network slices <NUM>.

Each of network slices <NUM> may represent a different function or application. For example, Slice <NUM> of network slices <NUM> may be a Mobile Broadband slice and Slice <NUM> of network slices <NUM> may be a Machine Type Communication network slice. Although illustrated as wireless devices <NUM> connected to only one of network slices <NUM>, respectively, in certain embodiments, one or more of wireless devices <NUM> may connect to more than one of network slices <NUM> concurrently.

Although the solutions described herein may be implemented in any appropriate type of system using any suitable components, particular embodiments of the described solutions may be implemented in a wireless network such as the example wireless communication network illustrated in <FIG>. In the example embodiment of <FIG>, the wireless communication network provides communication and other types of services to one or more wireless devices. In the illustrated embodiment, the wireless communication network includes one or more instances of network nodes that facilitate the wireless devices' access to and/or use of the services provided by the wireless communication network. The wireless communication network may further include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device, such as a landline telephone.

Network <NUM> may comprise one or more IP networks, public switched telephone networks (PSTNs), packet data networks, optical networks, wide area networks (WANs), local area networks (LANs), wireless local area networks (WLANs), wired networks, wireless networks, metropolitan area networks, and other networks to enable communication between devices.

The wireless communication network may represent any type of communication, telecommunication, data, cellular, and/or radio network or other type of system. In particular embodiments, the wireless communication network may be configured to operate according to specific standards or other types of predefined rules or procedures. Thus, particular embodiments of the wireless communication network may implement communication standards, such as Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), and/or other suitable <NUM>, <NUM>, <NUM>, or <NUM> standards; wireless local area network (WLAN) standards, such as the IEEE <NUM> standards; and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, and/or ZigBee standards.

<FIG> illustrates a wireless network comprising a more detailed view of network node <NUM> and wireless device (WD) <NUM>, in accordance with a particular embodiment. For simplicity, <FIG> only depicts network <NUM>, network nodes <NUM> and 200a, and WD <NUM>. Network node <NUM> comprises processor <NUM>, storage <NUM>, interface <NUM>, and antenna 201a. Similarly, WD <NUM> comprises processor <NUM>, storage <NUM>, interface <NUM> and antenna 211a. These components may work together in order to provide network node and/or wireless device functionality, such as providing wireless connections in a wireless network. In different embodiments, the wireless network may comprise any number of wired or wireless networks, network nodes, base stations, controllers, wireless devices, relay stations, and/or any other components that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections.

As used herein, "network node" refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a wireless device and/or with other equipment in the wireless communication network that enable and/or provide wireless access to the wireless device. Examples of network nodes include, but are not limited to, access points (APs), in particular radio access points. A network node may represent base stations (BSs), such as radio base stations. Particular examples of radio base stations include Node Bs, and evolved Node Bs (eNBs). "Network node" also includes one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Parts of a distributed radio base stations may also be referred to as nodes in a distributed antenna system (DAS).

As a particular non-limiting example, a base station may be a relay node or a relay donor node controlling a relay.

Yet further examples of network nodes include multi-standard radio (MSR) radio equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, Multi-cell/multicast Coordination Entities (MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SON nodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. More generally, however, network nodes may represent any suitable device (or group of devices) capable, configured, arranged, and/or operable to enable and/or provide a wireless device access to the wireless communication network or to provide some service to a wireless device that has accessed the wireless communication network.

As used herein, the term "radio node" is used generically to refer both to wireless devices and network nodes, as each is respectively described above.

In <FIG>, Network node <NUM> comprises processor <NUM>, storage <NUM>, interface <NUM>, and antenna 201a. These components are depicted as single boxes located within a single larger box. In practice however, a network node may comprise multiple different physical components that make up a single illustrated component (e.g., interface <NUM> may comprise terminals for coupling wires for a wired connection and a radio transceiver for a wireless connection). As another example, network node <NUM> may be a virtual network node in which multiple different physically separate components interact to provide the functionality of network node <NUM> (e.g., processor <NUM> may comprise three separate processors located in three separate enclosures, where each processor is responsible for a different function for a particular instance of network node <NUM>). Similarly, network node <NUM> may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, a BTS component and a BSC component, etc.), which may each have their own respective processor, storage, and interface components. In such a scenario, each unique NodeB and BSC pair, may be a separate network node. In such embodiments, some components may be duplicated (e.g., separate storage <NUM> for the different RATs) and some components may be reused (e.g., the same antenna 201a may be shared by the RATs).

Processor <NUM> may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node <NUM> components, such as storage <NUM>, network node <NUM> functionality. For example, processor <NUM> may execute instructions stored in storage <NUM>. Such functionality may include providing various wireless features discussed herein to a wireless device, such as WD <NUM>, including any of the features or benefits disclosed herein. For example, in certain embodiments processor <NUM> may execute instructions to perform the method discussed with respect to <FIG>.

Storage <NUM> may comprise any form of volatile or non-volatile computer readable memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), removable media, or any other suitable local or remote memory component. Storage <NUM> may store any suitable instructions, data or information, including software and encoded logic, utilized by network node <NUM>. Storage <NUM> may be used to store any calculations made by processor <NUM> and/or any data received via interface <NUM>.

Network node <NUM> also comprises interface <NUM> which may be used in the wired or wireless communication of signaling and/or data between network node <NUM>, network <NUM>, and/or WD <NUM>. For example, interface <NUM> may perform any formatting, coding, or translating that may be needed to allow network node <NUM> to send and receive data from network <NUM> over a wired connection. Interface <NUM> may also include a radio transmitter and/or receiver that may be coupled to or a part of antenna 201a. The radio may receive digital data that is to be sent out to other network nodes or WDs via a wireless connection. The radio may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters. The radio signal may then be transmitted via antenna 201a to the appropriate recipient (e.g., WD <NUM>).

Antenna 201a may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 201a may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between, for example, <NUM> and <NUM>.

As used herein, "wireless device" (WD) refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or another wireless device. Communicating wirelessly may involve transmitting and/or receiving wireless signals using electromagnetic signals, radio waves, infrared signals, and/or other types of signals suitable for conveying information through air. In particular embodiments, wireless devices may be configured to transmit and/or receive information without direct human interaction. For instance, a wireless device may be designed to transmit information to a network on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the network. Generally, a wireless device may represent any device capable of, configured for, arranged for, and/or operable for wireless communication, for example radio communication devices. Examples of wireless devices include, but are not limited to, user equipment (UE) such as smart phones. Further examples include wireless cameras, wireless-enabled tablet computers, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, and/or wireless customer-premises equipment (CPE).

As one specific example, a wireless device may represent a UE configured for communication in accordance with one or more communication standards promulgated by the <NUM>rd Generation Partnership Project (3GPP), such as 3GPP's GSM, UMTS, LTE, and/or <NUM> standards. As used herein, a "user equipment" or "UE" may not necessarily have a "user" in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but that may not initially be associated with a specific human user.

The wireless device may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, and may in this case be referred to as a D2D communication device.

As yet another specific example, in an Internet of Things (IoT) scenario, a wireless device may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another wireless device and/or a network node. The wireless device may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as a machine-type communication (MTC) device. As one particular example, the wireless device may be a UE implementing the 3GPP narrow band internet of things (NB-IoT) standard. Particular examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, e.g. refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a wireless device may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

A wireless device as described above may represent the endpoint of a wireless connection, in which case the device may be referred to as a wireless terminal. Furthermore, a wireless device as described above may be mobile, in which case it may also be referred to as a mobile device or a mobile terminal.

As depicted in <FIG>, WD <NUM> may be any type of wireless endpoint, mobile station, mobile phone, wireless local loop phone, smartphone, user equipment, desktop computer, PDA, cell phone, tablet, laptop, VoIP phone or handset, which is able to wirelessly send and receive data and/or signals to and from a network node, such as network node <NUM> and/or other WDs. WD <NUM> comprises processor <NUM>, storage <NUM>, interface <NUM>, and antenna 211a. Like network node <NUM>, the components of WD <NUM> are depicted as single boxes located within a single larger box, however in practice a wireless device may comprises multiple different physical components that make up a single illustrated component (e.g., storage <NUM> may comprise multiple discrete microchips, each microchip representing a portion of the total storage capacity).

Processor <NUM> may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in combination with other WD <NUM> components, such as storage <NUM>, WD <NUM> functionality. Such functionality may include providing various wireless features discussed herein, including any of the features or benefits disclosed herein. For example, in certain embodiments, processor <NUM> may execute instructions to perform the method discussed with respect to <FIG>.

Storage <NUM> may be any form of volatile or non-volatile memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), removable media, or any other suitable local or remote memory component. Storage <NUM> may store any suitable data, instructions, or information, including software and encoded logic, utilized by WD <NUM>. Storage <NUM> may be used to store any calculations made by processor <NUM> and/or any data received via interface <NUM>.

Interface <NUM> may be used in the wireless communication of signaling and/or data between WD <NUM> and network node <NUM>. For example, interface <NUM> may perform any formatting, coding, or translating that may be needed to allow WD <NUM> to send and receive data from network node <NUM> over a wireless connection. Interface <NUM> may also include a radio transmitter and/or receiver that may be coupled to or a part of antenna 211a. The radio may receive digital data that is to be sent out to network node <NUM> via a wireless connection. The radio may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters. The radio signal may then be transmitted via antenna 211a to network node <NUM>.

Antenna 211a may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In some embodiments, antenna 211a may comprise one or more omni-directional, sector or panel antennas operable to transmit/receive radio signals between <NUM> and <NUM>. For simplicity, antenna 211a may be considered a part of interface <NUM> to the extent that a wireless signal is being used.

<FIG> illustrates an example wireless device, user equipment (UE) <NUM>. UE <NUM> includes an antenna <NUM>, radio front-end circuitry <NUM>, processing circuitry <NUM>, and a computer-readable storage medium <NUM>. Antenna <NUM> may include one or more antennas or antenna arrays, and is configured to send and/or receive wireless signals, and is connected to radio front-end circuitry <NUM>. In certain alternative embodiments, wireless device <NUM> may not include antenna <NUM>, and antenna <NUM> may instead be separate from wireless device <NUM> and be connectable to wireless device <NUM> through an interface or port.

The radio front-end circuitry <NUM> may comprise various filters and amplifiers, is connected to antenna <NUM> and processing circuitry <NUM>, and is configured to condition signals communicated between antenna <NUM> and processing circuitry <NUM>. In certain alternative embodiments, wireless device <NUM> may not include radio front-end circuitry <NUM>, and processing circuitry <NUM> may instead be connected to antenna <NUM> without radio front-end circuitry <NUM>.

Processing circuitry <NUM> may include one or more of radio frequency (RF) transceiver circuitry, baseband processing circuitry, and application processing circuitry. In some embodiments, the RF transceiver circuitry, baseband processing circuitry, and application processing circuitry may be on separate chipsets. In alternative embodiments, part or all of the baseband processing circuitry and application processing circuitry may be combined into one chipset, and the RF transceiver circuitry may be on a separate chipset. In still alternative embodiments, part or all of the RF transceiver circuitry and baseband processing circuitry may be on the same chipset, and the application processing circuitry may be on a separate chipset. In yet other alternative embodiments, part or all of the RF transceiver circuitry, baseband processing circuitry, and application processing circuitry may be combined in the same chipset. Processing circuitry <NUM> may include, for example, one or more central processing units (CPUs), one or more microprocessors, one or more application specific integrated circuits (ASICs), and/or one or more field programmable gate arrays (FPGAs).

In particular embodiments, some or all of the functionality described herein as being provided by a wireless device may be provided by the processing circuitry <NUM> executing instructions stored on a computer-readable storage medium <NUM>. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry <NUM> without executing instructions stored on a computer-readable medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a computer-readable storage medium or not, the processing circuitry can be said to be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry <NUM> alone or to other components of UE <NUM>, but are enjoyed by the wireless device as a whole, and/or by end users and the wireless network generally.

Antenna <NUM>, radio front-end circuitry <NUM>, and/or processing circuitry <NUM> may be configured to perform any receiving operations described herein as being performed by a wireless device. Any information, data and/or signals may be received from a network node and/or another wireless device.

The processing circuitry <NUM> may be configured to perform any determining operations described herein as being performed by a wireless device. Determining as performed by processing circuitry <NUM> may include processing information obtained by the processing circuitry <NUM> by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the wireless device, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. In certain embodiments, processing circuitry may execute instructions to perform the method discussed with respect to <FIG>.

Antenna <NUM>, radio front-end circuitry <NUM>, and/or processing circuitry <NUM> may be configured to perform any transmitting operations described herein as being performed by a wireless device. Any information, data and/or signals may be transmitted to a network node and/or another wireless device.

Computer-readable storage medium <NUM> is generally operable to store instructions, such as a computer program, software, an application including one or more of logic, rules, code, tables, etc. and/or other instructions capable of being executed by a processor. Examples of computer-readable storage medium <NUM> include computer memory (for example, Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (for example, a hard disk), removable storage media (for example, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory computer-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry <NUM>. In some embodiments, processing circuitry <NUM> and computer-readable storage medium <NUM> may be considered to be integrated.

Alternative embodiments of UE <NUM> may include additional components beyond those shown in <FIG> that may be responsible for providing certain aspects of the UE's functionality, including any of the functionality described herein and/or any functionality necessary to support the solution described above. As just one example, UE <NUM> may include input interfaces, devices and circuits, and output interfaces, devices and circuits. Input interfaces, devices, and circuits are configured to allow input of information into UE <NUM>, and are connected to processing circuitry <NUM> to allow processing circuitry <NUM> to process the input information. For example, input interfaces, devices, and circuits may include a microphone, a proximity or other sensor, keys/buttons, a touch display, one or more cameras, a USB port, or other input elements. Output interfaces, devices, and circuits are configured to allow output of information from UE <NUM>, and are connected to processing circuitry <NUM> to allow processing circuitry <NUM> to output information from UE <NUM>. For example, output interfaces, devices, or circuits may include a speaker, a display, vibrating circuitry, a USB port, a headphone interface, or other output elements. Using one or more input and output interfaces, devices, and circuits, UE <NUM> may communicate with end users and/or the wireless network, and allow them to benefit from the functionality described herein.

As another example, UE <NUM> may include power source <NUM>. Power source <NUM> may comprise power management circuitry. Power source <NUM> may receive power from a power supply, which may either be comprised in, or be external to, power source <NUM>. For example, UE <NUM> may comprise a power supply in the form of a battery or battery pack which is connected to, or integrated in, power source <NUM>. As a further example, UE <NUM> may be connectable to an external power supply (such as an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power supply supplies power to power source <NUM>. Power source <NUM> may be connected to radio front-end circuitry <NUM>, processing circuitry <NUM>, and/or computer-readable storage medium <NUM> and be configured to supply UE <NUM>, including processing circuitry <NUM>, with power for performing the functionality described herein.

UE <NUM> may also include multiple sets of processing circuitry <NUM>, computer-readable storage medium <NUM>, radio circuitry <NUM>, and/or antenna <NUM> for different wireless technologies integrated into wireless device <NUM>, such as, for example, GSM, WCDMA, LTE, NR, Wi-Fi, or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chipsets and other components within wireless device <NUM>.

The third generation partnership project (3GPP) is currently working on standardization of Release <NUM> of the Long Term Evolution (LTE) concept. The architecture of the LTE system is shown in <FIG>, including radio access nodes (eNBs, Home eNBs - HeNBs, HeNB GW) and evolved packet core nodes (MME/S-GW). As it can be seen an S1 interface connects HeNBs/eNBs to the MME/S-GW and HeNBs to the HeNB GW, while an X2 interface connects peer eNBs/HeNBs, optionally via an X2 GW.

The management system assumed in this disclosure is shown in <FIG>. 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 Itf-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. MME and S-GWs.

It is not yet specified by 3GPP if and how the LTE architecture should evolve to meet the challenges of the <NUM> time frame. We can however assume that there will be evolved counterparts of the S1, X2 and Uu interfaces and that any new RAT would be integrated with the LTE radio interface at RAN level in a similar fashion as the way LTE Dual Connectivity is defined. The overall principles disclosed herein would work for both an LTE-like architecture and a new architecture based on an evolution of the S1 interface.

When it comes to the <NUM> RAN architecture, there could be novel interfaces e.g. between some synchronous and asynchronous functionalities. Different discussions are ongoing in the industry about a possible future evolution of the current RAN architecture. From a starting point in a macro site based topology the introduction of low power cells, the evolution of the transport network between the different radio base station sites, the radio base station hardware evolution, the increased need for processing power and so on, have given rise to new challenges and opportunities. Several strong forces are at work on the RAN architecture, pulling in sometimes different directions. Some, like the gains of coordination, hardware pooling gains, energy saving gains and the evolution of the backhaul/fronthaul network are working in favor of a more centralized deployment while others are working towards de-centralization, such as very low latency requirements for some <NUM> use cases e.g. mission critical MTC applications. The terms fronthaul and backhaul are used in relation to the base station. The traditional definition for fronthaul is the CPRI based fiber link between the baseband (Main Unit) and the Radio Unit. The backhaul refers to the transport network used for S1/X2-interfaces.

The recent evolution in backhaul/fronthaul has indeed opened up the possibility to centralize the baseband, often referred to as C-RAN. C-RAN is a term that can be interpreted in different ways. For some it means a "baseband hotel" like solutions in which the basebands from many sites are collocated to a central site but there is no tight connection and fast exchange of data between the sites. The most common interpretation is maybe "Centralized RAN" where there is at least some kind of coordination between the basebands. A potentially attractive solution is the smaller centralized RAN that is based on a macro base station and the lower power nodes covered by it. In this configuration a tight coordination between the macro and the low power nodes can often give considerable gains. The term "Coordinated RAN" is an often used interpretation that focuses on the coordination gains of the centralization. Other more futuristic interpretations of C-RAN include "cloud" based and "virtualized" RAN solutions where the radio Network functionality is supported on generic hardware (general purpose processors) and possibly as virtual machines.

A centralized deployment can be driven by one or several forces like e.g. a possible ease of maintenance, upgrade and less need for sites as well as harvesting of coordination gains. A common misconception is that there is a large pooling gain and a corresponding HW saving to be done by the centralization. The pooling gain is large over the first number of pooled cells but then diminishes quickly. One key advantage of having the basebands from a larger number of sites co-located and interconnected is the tight coordination that it allows. Examples of these are UL CoMP and combining several sector/carriers into one cell. The gains of these features can sometimes be significant in relation to the gains of looser coordination schemes such as e.g. eICIC that can be done over standard interfaces (X2) without co-location of the baseband.

An attractive C-RAN deployment from a coordination gain perspective is the C-RAN built around a larger macro site, normally with several frequency bands, and a number of lower power radios, covered by the macro site, that are tightly integrated into the macro over high-speed interconnect. The largest gains are expected to be seen in deployment scenarios such as stadiums and malls. An important consideration for any C-RAN deployment is the transport over the fronthaul, i.e. the connection between the centralized baseband part and the radios, "the first mile". The cost of the fronthaul, which vary rather greatly between markets, needs to be weighed against the benefits.

Future discussions in 3GPP may lead to a RAN functional split shown in <FIG>. Therein, the RAN functions are classified in synchronous (placed in a logical node called s-eNB) and asynchronous (placed in a logical node called a-eNB) functions. The instances of functions associated to the s-eNB i.e. the synchronous functions (SFs) are placed at the closest node to the air interfaces. These will form what is called a synchronous functional group (SFG). Meanwhile, the instances of the asynchronous functions (AFs) associated to the eNB-a (also called a-eNB in the current document) can be flexibly instantiated either at closest node to the air interface (i.e. the same node where the s-eNB (also called eNB-s in the current document) functions are instantiated) or in fixed network nodes (FNNs).

There are several architecture options discussed and documented in the 3GPP TR <NUM>. The below is the Option <NUM> which reflects an option that will certainly be modified in the course of the ongoing study and thus modifications can be expected. The below is section <NUM> from 3GPP TR <NUM>.

The NextGen network reference architecture should consider the following aspects:.

Allow scalability of UP and CP functions independently.

Concurrent access to local and centralized services is supported as follows.

NOTE <NUM>: The control plane can also configure multiple UP functions in the single PDU session case for local data network access.

<FIG> (labeled as Figure <NUM>. <NUM>-<NUM> in section <NUM> from 3GPP TR <NUM>. <NUM>) depicts the non-roaming architecture functional view.

<FIG> (labeled as Figure <NUM>. <NUM>-<NUM> in section <NUM> from 3GPP TR <NUM>. <NUM>) depicts the non-roaming architecture for UEs concurrently accessing a local and a central data network using multiple PDU Sessions.

<FIG> (labeled as Figure <NUM>. <NUM>-<NUM> in section <NUM> from 3GPP TR <NUM>. <NUM>) depicts the non-roaming architecture in case concurrent access to local and central data networks is provided within a single PDU session:.

<FIG> (labeled as figure <NUM>. <NUM>-<NUM> from section <NUM> from 3GPP TR <NUM>. <NUM>) depicts the roaming architecture in case of home routed scenario:.

<FIG> (labeled as figure <NUM>. <NUM>-<NUM> from section <NUM> from 3GPP TR <NUM>. <NUM>) depicts the roaming architecture in case of local break out scenario.

Editor's note: The choice between NG6* and NG6 depends on whether the PDU Session has a single IP address/prefix or multiple IP address/prefixes. It is FFS whether both types need to be supported. Whether the distinction between NG6 and NG6* is needed is also FFS.

Editor's note: The interconnection model for all control plane network functions is FFS.

Editor's note: Need for NG8 from H-SMF to NG-SDM (i.e. in the home routed scenario) is FFS.

NOTE <NUM>: Regardless of the number of CCFs, there is only one NAS interface instance between the UE and the CN, terminated at one of the CCFs that implements at least access authentication and mobility management.

NOTE <NUM>: Criteria to select multi-vendor open (standardized) interfaces should be determined.

The <NUM> Reference Architecture consist of the following functions:.

The following is a high level split of functionality between the control plane and the user plane.

The NG Mobility Management function (MMF) includes the following functionality:.

The NG Authentication function (AUF) includes the following functionality:.

Editor's note: AUF functionality and roaming architecture needs to be updated based on outcome of Key issue #<NUM>, SA3 work on Security framework for NextGen.

The NG Session Management function (SMF) includes the following functionality:.

NOTE <NUM>: Not all of the MMF, SMF, AUF functions are required to be supported in an instance of CCFs of a network slice.

The NG Core User plane function includes the following functionality:.

NOTE <NUM>: Not all of the UPF functions are required to be supported in an instance of user plane function of a network slice.

The NG Policy function includes the following functionality:.

Editor's note: The need for an interface between NG Policy Function and SDM is FFS.

The NG ASR supports the following functionality:.

Editor's note: ASR functionality needs to be updated based on outcome of SA3 work on Security framework for NextGen.

The NG SDM supports the following functionality:.

The <NUM> Reference Architecture contain the following reference points:.

<FIG> is a block diagram illustrating an embodiment of a user equipment (UE) connected to multiple network slices, in accordance with certain embodiments. UE has a single NAS termination point at Common CP Function (CCF). This results in RAN having a single Control Plane (CP) interface for that UE. The User Plane (UP) is shown as being separated one per Core Network Instance (CNI).

When it comes to one physical RAN used for multiple network slices, two aspects should be taken into account. The first aspect is that network slicing should make possible to support several different virtual networks on the same physical network infrastructure in order to reduce costs and energy consumption compared to deploying separate physical networks for the different use case or business scenarios. In order to fully exploit this benefit, it is required that the slicing concept allows for efficient usage of common resources such as radio resources and infrastructure, and transport links between the slices such as fronthaul and backhaul. The second aspect is that mechanisms are required to protect common channels or resources used for UEs accessing system so that congestion in one slice does not have a negative impact on another slice (often called slice isolation). Currently in 3GPP system there is some support for protecting common control channels for extensive load from different services. These mechanisms include Access Class Barring, Enhanced Access Barring, Service Specific Access Barring, as well as implementation specific admission control etc. These are described in the next section.

One problem which has not been addressed is related to limited slice availability in the network. Limited slice availability could be scenarios where a given network slice is not supported in all cells of the cellular network or not for all UEs/subscribers in all cells. If this is the case problems will occur when the UE is moving in or out of areas with different slice support. Problem will also occur when UE is connecting to the network for the first time (or is re-connecting) in case the slice the UE wants to connect to or is already registered in is not available in that area. Accordingly there is proposed herein several embodiments for handling limited slice availability in the network. The advantage of the solutions is that limited slice availability is handled in a consistent way avoiding issues such as:.

It is to be noted that any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to the other embodiments, and vice versa.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein.

Some of the embodiments contemplated herein will now be described more fully hereinafter with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of this disclosure and the invention should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the inventive concept to those skilled in the art.

The work on network slicing has progressed in the 3GPP meetings with some text and agreements being captured in the technical reports etc. One topic however that has not been discussed so much is if a given network slice should be available in all base stations / cells or if the concept should support network slices which are only available in a subset of the base station / cells.

Although it would be technically simple if all slices where available in all base station or cell, we assume this not possible. Operator may want to offer a slice only in a specific region and prefer not to configure other network nodes in other regions to support the same slice. There could also be scenarios where access to a slice is very location dependent e.g. only within an enterprise campus, factory, processing planet,. meeting some specific business or performance needs which cannot be provided network wide. So from this we draw the conclusion that all network slices will not be available in all base station of a cellular network. the networks will typically support slices with limited availability. Limited availability here could mean.

With the assumptions that slices are not always available solutions are here proposed for how the information about availability can be handled inside the network. The solutions are as follows:.

In order to get a consistent UE performance, solutions are proposed on how to handle the limited slice availability towards the UE. Several embodiments are considered:.

Cellular networks typically support power saving stage like CN IDLE where the UE is allowed to move in an area without notifying the network, listening for paging from the network. In CN IDLE this area is the area of a Tracking Area List. But it could also be an area of a cell or a list of cells.

In networks with limited slice availability a given slice may not be supported in all cells. A problem could then occur where the UE in power saving is camping on a cell which does not support the slice the UE is connected to. Assuming the cell does not provide information about all slices it supports or that the UE, in order to save power does not read such information, there is no way the UE would know that the slice is no longer supported. This problem is addressed with the following embodiment:.

When the UE is active in the system it is capable of sending / receiving data from the network. Typically, the network controls the mobility in this state using handover procedures. Assuming the network does not support all slices in all nodes, cells or frequency bands. In this case the UE would lose slice connectivity if it moves to an area where the slice is not supported. This could lead to poor service performance. This problem is addressed with the following embodiment:.

In this case the UE will send a request to the network to transition to an active state e.g. to perform signaling or user data transfer. The receiving network node can based on the knowledge of which slices the UE are connected to or wants to connected, together with information about slice availability in the network decide to either accept or reject the UE request.

The reject message that the network sends to the UE can include re-direction instructions to other frequency bands etc. where the slice is supported.

There is also embodiment in the UE for handling limited slice availability. These embodiments could include the UE reading information from the broadcast channel of the system (the information is broadcasted from the network). The information is related to the slice availability in the cell, frequency for which the broadcast information is associated with. Different sub embodiments exist:.

Once the UE reads the information about the slice availability it can take different actions:.

In the network the knowledge about slice availability can be used in access control, as well as assigning resources too different UEs. It is possible for the network to assign the UE a slice policy parameter which is associated with a specific slice or a group of slice. When the UE request resources for a slice indicating this slice policy parameter the RAN can either accept or reject the UE connecting e.g. based on if the slice is available or not.

Similar functionality can also be applied between network nodes when one node is asking for resources for a slice that a UE is connected to. The resource request can include information about which slice the UE wants to use or is connected to. The target node (e.g. the serving base station, or target base station at handover) can then either accept or reject request based on slice availability. Also partial reject is possible where resources for some slices are accepted while other slices are not.

Other functionality that can be applied between network nodes, could be for one node e.g. CN node to generate a mobility restriction list which is sent to another node e.g. RAN node. This mobility restriction list may be based on information about which slices the UE is connected to or may access, and information about slice availability in other nodes. This mobility restriction list can then be used by the other node when controlling the mobility of the UE e.g. to avoid that the UE goes to an area where a given slice is not supported. The mobility restriction list can also be provided to the UE to control the UE cell selection.

<FIG> is a flow diagram of a method in a network node. The method may be performed in any suitable network node, such as a radio access network node or a core network node. Examples of radio access network nodes and core network nodes are illustrated in <FIG>. As one example, the method may be performed by network node <NUM> of <FIG>. At step S <NUM>, network node <NUM> obtains slice availability associated with one or more neighboring network nodes. The neighboring network nodes may include the same type of node as the network node performing the method (e.g., neighboring nodes of an eNB may include other eNBs, neighboring nodes of an MME may include other MMEs, neighboring nodes of a gateway may include other gateways, etc.) In addition, or in the alternative, neighboring nodes may include different types of nodes. As an example, in certain embodiments, a core network node may obtain slice availability associated with radio access network nodes, As another example, in certain embodiments, a radio access node may obtain slice availability associated with core network nodes. In certain embodiments, the network slice availability indicates which of a plurality of network slices is supported by each of the one or more neighboring network nodes. For example, in certain embodiments, neighboring network nodes may have limited network slice availability, such that one or more of the neighboring network nodes may support only a limited subset of all network slices and/or the neighboring network nodes may support different network slices.

At step S1320, network node <NUM> manages slice connectivity of a wireless device, such as wireless device <NUM> of <FIG> or UE <NUM> of <FIG>, based on the network slice availability of the one or more neighboring network nodes. In this manner, the performance of the wireless network, including wireless device <NUM> and network node <NUM>, may be improved by managing the connectivity using the obtained network slice availability.

In certain embodiments, certain steps in the method discussed in <FIG> may comprise substeps. For example, in certain embodiments, the one or more neighboring nodes comprise a plurality of core network nodes. In some embodiments, step S <NUM> may comprise optional substeps. At substep S1321, network node <NUM> receives a slice identifier indicating which of the network slices wireless device <NUM> requests to use. In some embodiments, a single network slice identifier is received at network node <NUM>, or alternatively, more than one network slice identifier is received. For example, in some embodiments, the slice identifier received at network node <NUM> may comprise separate slice identifiers for each of the network slices wireless device <NUM> requests to use. At substep <NUM>, network node <NUM> selects one or more of the core network nodes based on the network slice availability. Selecting one or more of the core network nodes may include selecting a single core network node, selecting a subset of core network nodes (e.g., a subset comprising more than one core network node, but fewer than all core network nodes), or selecting all core network nodes. For example, the core network node(s) may be selected based on a functional group thereof. The one or more selected core network node supports the network slice indicated by the slice identifier. At substep <NUM>, network node <NUM> provides wireless device <NUM> with access to the selected core network node. In this manner, network node <NUM> may ensure that wireless device <NUM> is provided the proper access to a core network node that supports the requested network slice. As discussed above, this is particularly important when there is limited network slice availability at one or more network nodes, such as limited network slice availability at one or more core network nodes.

In certain embodiments, the one or more neighboring nodes comprise a plurality of radio network nodes. For example, the one or more neighboring nodes may comprise one or more evolved NodeB or any other radio network nodes. As an example, the one or more neighboring nodes may comprise one or more radio network nodes that make up at least a portion of radio access network <NUM>. In some embodiments, step <NUM> of managing the slice connectivity of the wireless device comprises substeps. For example, in certain embodiments, network node <NUM> may determine which of the network slices wireless device <NUM> is connected to. Network node <NUM> may then select one of the radio network nodes for handover based on the network slice availability. The selected radio network node supports the network slice(s) that wireless device <NUM> is connected to. Network node <NUM> may then initiate handover of wireless device <NUM> to the selected radio network node. In this manner, network node may ensure that wireless device <NUM> is handed over to a radio network node that supports the network slice(s) it currently is connected to.

In certain embodiments, managing slice connectivity includes initiating removal of a connection between the wireless device and a network slice that is unsupported by a neighboring network node selected for a handover procedure involving the wireless device. For example, network node <NUM> may, during handover or prior to handover, may remove connection to particular network slices that would not be supported in the new network node. In this manner, network node <NUM> may prevent wireless device <NUM> from attempting to access an unsupported network slice after handover.

In certain embodiments, managing slice connectivity includes receiving, from wireless device <NUM>, a request to connect to a first network slice. In some embodiments, network node <NUM> may determine that the first network node does not support the first network slice. In response, network node <NUM> may reject the request and redirect wireless device <NUM> to another network slice. In this manner, network node <NUM> may prevent wireless device <NUM> from attempting to access an unsupported network slice.

In certain embodiments, managing slice connectivity includes receiving, from the wireless device, a request to connect to a first network slice. In some embodiments, network node <NUM> may determine that there is a likelihood of wireless device <NUM> moving to a neighboring network node that does not support the first network slice. For example, network node <NUM> may use information regarding wireless device <NUM>'s movement or historical connection information to predict that wireless device <NUM> is likely to move to one or more neighboring network nodes that do not support the first network slice. In response, network node <NUM> may reject the request to connect to the first network slice and may redirect the wireless device to another network slice (i.e., based on the likelihood of the wireless device moving to a neighboring network node that does not support the first network slice).

In certain embodiments, the plurality of network slices comprises a first network slice. In certain embodiments, the method discussed in <FIG> may include optional additional steps. At step S1330, network node <NUM> creates a paging area with consistent network slice availability for the wireless device. The paging area comprises one or more of the neighboring network nodes that, based on the network slice availability, support the first network slice. For example, the paging area may comprise a group of neighboring network nodes, e.g., a coverage area, in which the network slice availability does not change. In some embodiments, the paging area may be specific to wireless device <NUM>. For example, the paging area may comprise a group of neighboring network nodes that support all of the network slices that wireless device <NUM> is connected to and/or may request access to and/or that are supported by wireless device <NUM>. At optional step S1340, network node <NUM> may communicate an indication of the paging area that supports the first network slice to the wireless device. In this manner, network node <NUM> may provide information to wireless device <NUM> that prevents unnecessary mobility signaling when moving within the paging area.

In certain embodiments, network node <NUM> may determine that wireless device <NUM> has added or removed a connection to one of the network slices. Network node <NUM> may, in response, create a new paging area with consistent network slice availability for the wireless device. For example, network node <NUM> may determine which neighboring network nodes support the changed set of network slices and create the new paging area accordingly. Network node <NUM> may then communicate the new paging area to the wireless device. In this manner, network node <NUM> may continue to prevent unnecessary mobility signaling by wireless device <NUM> even when wireless device <NUM> adds or removes connections to network slices.

In some embodiments, managing the slice connectivity of wireless device <NUM> comprises a substep of removing a connection between wireless device <NUM> and the first network slice. For example, network node <NUM> determine, based on the network slice availability, that the wireless device is connected to a radio access node that does not support the first network slice. In response, network node <NUM> may remove the connection to the first network slice. In this manner, wireless device <NUM> will be prevented from attempted to access a network slice that is not supported by the connected radio access node.

In some embodiments, managing the slice connectivity of wireless device <NUM> comprises a substep of adding a connection between wireless device <NUM> and the first network slice. For example, network node may determine, based on the network slice availability, that the wireless device is connected to a radio access node that supports the first network slice. In response, network node may add a connection to the first network slice. In this manner, wireless device <NUM> may be provided a connection to the network slice when available through the radio access node. Accordingly, wireless device <NUM> may be connected to a network slice that optimizes the performance of wireless device <NUM> and/or the wireless network. For example, wireless device <NUM> may operate on alternative network slices when the first network slice is unavailable on the currently connected-to radio access node. If the first network slice become available, either through the same radio access node or after changing radio access nodes, then it may be preferable to connect wireless device <NUM> to first network slice.

In some embodiments, managing the slice connectivity of wireless device <NUM> comprises a substep of rejecting a request to connect the wireless device to the first network slice in response to determining that the wireless device is connected to a radio access node that does not support the first network slice. For example, wireless device <NUM> may have been previously connected to a radio access node that supported the first network slice, but has now connected to a second radio access node that does not support the first network slice. As another example, the connected-to radio access node may no longer support the first network slice, or may no longer have resources to connect wireless device <NUM> to the first network slice, and therefore does not support the first network slice.

In certain embodiments, each of the network slices comprises a respective logical network that supports a respective network function having different characteristics than the network functions of the other network slices. In certain embodiments, each of the network slices supports a respective business operation that is independent of the business operations supported by the other network slices.

In certain embodiments, at least a portion of the network slice availability is obtained during an initial connection set up between the first network node and at least one of the neighboring network nodes. For example, each network node in the wireless network may access their own network slice availability, e.g., which network slices are supported on the network node. During initial connection set up between the nodes, network node <NUM> may communicate its network slice availability information and receive the same from the neighboring nodes. In this manner, network node <NUM> may obtain network slice availability information during the initial connection set up.

In certain embodiments, at least a portion of the network slice availability is obtained from handover signaling between the first network node and one of the neighboring network nodes. For example, network nodes may exchange their network slice availability when communicating the signally for handover of wireless device <NUM>. Additionally, in certain embodiments, once the network node has obtained the network slice availability of one of its neighboring nodes (e.g., neighboring node A), the network node may forward neighboring node A's network slice availability to another of its neighboring nodes (e.g., neighboring node B), Thus, network nodes may exchange their own network slice availability and/or the network slice availability of other network nodes. In some embodiments, the network slice availability may be incorporated into the existing handover signaling, e.g., as an additional parameter or message.

In certain embodiments, at least a portion of the network slice availability is obtained in response to the wireless device performing a state transition from an idle state to an active state. For example, wireless device <NUM> may transmit network slice availability information known to wireless device <NUM> to network node <NUM> during the state transition. In this manner, network node <NUM> may obtain network slice availability information that may be useful for managing the connection of wireless device <NUM> as it transitions to an active state.

In certain embodiments, the method discussed in <FIG> comprises the additional step of maintaining slice connection information at network node <NUM>. The slice connection information may indicate which of the network slices wireless device <NUM> is connected to. Network node <NUM> may receiving an indication that wireless device <NUM> has added or removed a connection to one of the network slices. For example, wireless device <NUM> may no longer require access to a network slice or may want access to another or additional network slice. Network node <NUM> may update its slice connection information (slice connection information maintained by network node <NUM>) based on the received indication. In this manner, network node <NUM> may maintain current slice connection information for wireless device <NUM>. The slice connection information may be used for managing the connection of wireless device <NUM> to one or more network slices, including management at another network node, e.g., through signaling the slice connection information.

In certain embodiments, network node <NUM> may broadcast a parameter associated with its network slice availability and/or the network slice availability of one or more of the neighboring network nodes. In some embodiments, network node <NUM> communicates network node <NUM>'s network slice availability to one or more of the neighboring network nodes. Neighboring network nodes and/or wireless device <NUM> may use information determined from the parameter to determine the network slice availability of the network node <NUM> and/or one or more of the neighboring network nodes. In this manner, network node <NUM> may provide information to wireless device <NUM>, or other network nodes, of the network slice availability that may be used for managing connections in a limited availability scenario.

A network slice may encompass functionality that is provided by a single network node or functionality that is distributed throughout a network. The functionality may be distributed in any suitable manner. For example, in certain embodiments, a first network node may provide a portion of the functionality of a network slice, and a second network node may provide another portion of the functionality of the network slice. Thus, selecting one or more core network nodes may comprise selecting one or more functional groups implemented on one or more network nodes. For example, network node <NUM> may select a function of several core network nodes and provide access to those functions across the several core network nodes to wireless device <NUM>. Selecting a core network node may comprise selecting the network node in its entirety or selecting a functional group or function within the core network node that is limited to a subset of components within the network node (e.g., a subset of hardware, software, resources, memory, etc.).

<FIG> is a flow diagram of a method in a wireless device, such as wireless device <NUM> in <FIG> or UE <NUM> in <FIG>, in accordance with certain embodiments. At step S1410, wireless device <NUM> receives, from a network node, such as network node <NUM>, information associated with network slice availability in a network comprising the network node. In some embodiments, at least a portion of the information associated with network slice availability is received in a broadcast from the network node. In some embodiments, at least a portion of the information associated with network slice availability is based on network configuration information received from the network prior to receiving the broadcast from the network node.

At step S1420, wireless device <NUM> communicates a connectivity request to network node <NUM> for access to a first network slice. The first network slice may be selected by wireless device <NUM> based at least in part on the information associated with network slice availability received from the network node. For example, wireless device <NUM> may receive network slice availability information that indicates that network node <NUM> supports one or more network slices. In response, wireless device <NUM> may communicate its connectivity request for a network slice that is supported by network node <NUM>. The first network slice may be a first choice of wireless device based on its connection needs, or alternatively, may be an alternative choice based on the availability at network node <NUM>. In some embodiments, wireless device <NUM> communicates the information associated with network slice availability to network node <NUM> when performing a state transition from an idle state to an active state.

In certain embodiments, the method discussed in <FIG> includes additional optional steps. In certain embodiments, wireless device <NUM> initiates the setup of a network slice connection based on the information associated with network slice availability. In certain embodiments, wireless device <NUM> initiates a removal of a network slice connection based on the information associated with network slice availability. In this manner, wireless device <NUM> may adjust the network slice connections based on the information associated with network slice availability. For example, wireless device <NUM> may only want to maintain or establish connections to network slices that are supported on the network nodes wireless device <NUM> is connected to. In doing so, wireless device <NUM> may prevent attempts at accessing unsupported network slices.

In certain embodiments, wireless device <NUM> performs reselection of one or more of a cell, a frequency, or a radio access technology based on the information associated with network slice availability. For example, a particular network slice may not be available on the current cell, frequency, and/or radio access technology. Wireless device <NUM> may then perform reselection to select a cell, frequency, and/or radio access technology that supports the network slice. In some embodiments, performing reselection includes determining that a current cell, frequency, or radio access technology (RAT) on which the wireless device is operating does not support the first network slice. Wireless device <NUM> may then select a new cell, frequency, or RAT that supports the first network slice. Once selected, wireless device <NUM> may then access the first network slice through the new cell, frequency, or RAT. In this manner, wireless device <NUM> may connect to the desired network slice, even if it is not available on the current cell, frequency, or radio access technology.

In certain embodiments, wireless device <NUM> communicates a slice identifier indicating the first network slice. For example wireless device <NUM> may communicate the slice identifier to network node <NUM>. Network node <NUM> may then identify which network slice wireless device requests access to. In response, network node <NUM> may determine which core network nodes support the desired network slices. Wireless device <NUM> may then access a core network node that supports the first network slice indicated by the slice identifier. In this manner, wireless device <NUM> may provide information for network node <NUM> to select the correct core network nodes in order to provide the desired connections to one or more network slices.

In certain embodiments, wireless device <NUM> receives an initiation of a handover procedure to a second network node. For example, the second network node may support the first network slice. Wireless device <NUM> may then complete handover to a second network node and access the first network slice through the second network node. In this manner, wireless device may continue to access the first network slice despite being handed over to a second network node.

In certain embodiments, wireless device <NUM> receives a paging area with consistent network slice availability for the wireless device. The paging area comprises one or more neighboring network nodes that, based on network slice availability of the neighboring network nodes, support the first network slice. For example, the paging area may include an indication of which of the neighboring network nodes support the first network slice. Wireless device <NUM> may then prevent the generation of mobility signaling when the wireless device is within the paging area. For example, wireless device may suppress any mobility signaling when moving within the paging area, even if moving between network nodes. In some embodiments, wireless device <NUM> communicates area update signaling from the wireless device when the wireless device moves outside the received paging area. For example, if wireless device <NUM> moves to a network node that does not support the first network slice, wireless device <NUM> may generate an area update to send to the current network node. Wireless device <NUM> may then receive a new paging area with consistent network slice availability for the wireless device. For example, wireless device <NUM> may receive a paging area that includes neighboring network nodes that support the same network slices supported at the current network node wireless device <NUM> is connected to.

In certain embodiments, wireless device <NUM> communicates wireless device <NUM>'s network slice connection information to the network node. Wireless device <NUM> may then receive handover signaling from the network node. The handover signaling may include a handover candidate based on the network slice availability of neighboring network nodes and the network slice connection information of the wireless device. For example, the handover candidate may be selected to be a network node that supports each of the network slices that wireless device <NUM> is connected to or is likely to request based on the network slice connection information. Wireless device <NUM> may then connect to the handover candidate. In this manner, wireless device <NUM> may provide sufficient information for network node <NUM> to select an appropriate handover candidate that supports the network slices wireless device is connected to. In some embodiments, the handover candidate does not support the first network slice. Wireless device <NUM> may then connect to a second network slice. For example, wireless device <NUM> may connect to a network slice that most closely relates to the first network slice or provides the most overlapping functionality provided by the first network slice.

Any steps or features described herein are merely illustrative of certain embodiments. It is not required that all embodiments incorporate all the steps or features disclosed nor that the steps be performed in the exact order depicted or described herein. Furthermore, some embodiments may include steps or features not illustrated or described herein, including steps inherent to one or more of the steps disclosed herein.

Any appropriate steps, methods, or functions may be performed through a computer program product that may, for example, be executed by the components and equipment illustrated in one or more of the figures above. For example, storage <NUM> may comprise computer readable means on which a computer program can be stored. The computer program may include instructions which cause processor <NUM> (and any operatively coupled entities and devices, such as interface <NUM> and storage <NUM>) to execute methods according to embodiments described herein. The computer program and/or computer program product may thus provide means for performing any steps herein disclosed.

Any appropriate steps, methods, or functions may be performed through one or more functional modules. Each functional module may comprise software, computer programs, sub-routines, libraries, source code, or any other form of executable instructions that are executed by, for example, a processor. In some embodiments, each functional module may be implemented in hardware and/or in software. For example, one or more or all functional modules may be implemented by processors <NUM> and/or <NUM>, possibly in cooperation with storage <NUM> and/or <NUM>. Processors <NUM> and/or <NUM> and storage <NUM> and/or <NUM> may thus be arranged to allow processors <NUM> and/or <NUM> to fetch instructions from storage <NUM> and/or <NUM> and execute the fetched instructions to allow the respective functional module to perform any steps or functions disclosed herein.

Certain aspects of the inventive concept have mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, embodiments other than the ones disclosed above are equally possible and within the scope of the inventive concept. Similarly, while a number of different combinations have been discussed, all possible combinations have not been disclosed. One skilled in the art would appreciate that other combinations exist and are within the scope of the inventive concept. Moreover, as is understood by the skilled person, the herein disclosed embodiments are as such applicable also to other standards and communication systems and any feature from a particular figure disclosed in connection with other features may be applicable to any other figure and or combined with different features.

Modifications, additions, or omissions may be made to the systems and apparatuses described herein without departing from the scope of the disclosure. The components of the systems and apparatuses may be integrated or separated. Moreover, the operations of the systems and apparatuses may be performed by more, fewer, or other components. Additionally, operations of the systems and apparatuses may be performed using any suitable logic comprising software, hardware, and/or other logic. As used in this document, "each" refers to each member of a set or each member of a subset of a set.

Claim 1:
A method performed by a first network node, comprising:
obtaining (S1310) network slice availability associated with one or more neighboring network nodes, the network slice availability indicating which of a plurality of network slices is supported by each of the one or more neighboring network nodes;
managing (S1320) slice connectivity of the wireless device based on the network slice availability of the one or more neighboring network nodes;
creating (S1330) a paging area with consistent network slice availability for the wireless device, wherein the paging area comprises one or more of the neighboring network nodes that, based on the network slice availability, support a first network slice of the plurality of network slices; and
communicating (S1340) an indication of the paging area that supports the first network slice to the wireless device.