WO2021155942A1

WO2021155942A1 - Communication system

Info

Publication number: WO2021155942A1
Application number: PCT/EP2020/053058
Authority: WO
Inventors: Tsunehiko Chiba; Andres ARJONA; Subramanya CHANDRASHEKAR; Pawel Hieronim NOWAK
Original assignee: Nokia Technologies Oy
Priority date: 2020-02-07
Filing date: 2020-02-07
Publication date: 2021-08-12

Abstract

There is provided an apparatus configured to receive, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

Description

Title

COMMUNICATION SYSTEM

Field [0001] The present application relates to a method, apparatus, and computer program.

Background

[0002] A communication system can be seen as a facility that enables communication sessions between two or more entities such as user terminals, base stations/access nodes and/or other nodes by providing carriers between the various entities involved in the communications path. A communication system can be provided, for example, by means of a communication network and one or more compatible communication devices. The communication sessions may comprise, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and/or content data and so on. Non-limiting examples of services provided comprise two-way or multi-way calls, data communication or multimedia services and access to a data network system, such as the Internet.

Summary [0003] According to a first aspect, there is provided an apparatus for a control plane function, the apparatus comprising: means for receiving, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell. [0004] The apparatus may further comprise means for using the cell-specific identification in response to the terminal service connection event to select a user plane function for a terminal.

[0005] The apparatus may further comprise means for selecting a user plane function based at least on part on said cell-specific information. [0006] The transmission may comprise an identification of a public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell in advance of a terminal service connection event involving said first cell, and the apparatus further comprises: means for receiving a service request from a terminal that identifies a mode supported by a cell and at least one logical network; and means for using said service request, identification of the public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell to select a user plane function for said terminal.

[0007] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0008] The cell-specific indication of at least one mode may be an indication of whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be, e.g., a 5G network or a Long Term Evolution network.

[0009] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0010] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0011] The terminal service connection event may be a handover of a terminal from or to said first cell.

[0012] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal.

[0013] The cell-specific information may comprise a slice identification.

[0014] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[0015] According to a second aspect, there is provided an apparatus for a user plane function, the apparatus comprising: means for transmitting, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell. [0016] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0017] The cell-specific indication of at least one mode may be an indication of whether the first cell uses control plane functions of only a first network type, only a second network type, or any of the first and second network types depending on a current configuration. The first network type may be a 5G network and the second network type may be a Long Term Evolution network.

[0018] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0019] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0020] The terminal service connection event may be a handover of a terminal from or to said first cell.

[0021] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal. [0022] The cell-specific information may comprise a slice identification.

[0023] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[0024] According to a third aspect, there is provided an apparatus for a control plane function, the apparatus comprising: at least one processor; and at least one memory comprising code that, when executed by the at least one processor, causes the apparatus to receive, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

[0025] The apparatus may further be caused to use the cell-specific identification in response to the terminal service connection event to select a user plane function for a terminal. [0026] The apparatus may further be caused to select a user plane function based at least on part on said cell-specific information.

[0027] The transmission may comprise an identification of a public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell in advance of a terminal service connection event involving said first cell, and the apparatus may further be caused to: receive a service request from a terminal that identifies a mode supported by a cell and at least one logical network; and use said service request, identification of the public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell to select a user plane function for said terminal.

[0028] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability. [0029] The cell-specific indication of at least one mode may be an indication of whether the first cell uses control plane functions of only a first network type, only a second network type, or any of the first and second network types depending on a current configuration. The first network type may be a 5G network and the second network type may be a Long Term Evolution network. [0030] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0031] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid. [0032] The terminal service connection event may be a handover of a terminal from or to said first cell.

[0033] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal.

[0034] The cell-specific information may comprise a slice identification. [0035] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[0036] According to a fourth aspect, there is provided an apparatus for a user plane function, the apparatus comprising: at least one processor; and at least one memory comprising code that, when executed by the at least one processor, causes the apparatus to transmit, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

[0037] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0038] The cell-specific indication of at least one mode may be an indication of whether the first cell uses control plane functions of only a first network type, only a second network type, or any of the first and second network types depending on a current configuration. The first network type may be a 5G network and the second network type may be a Long Term Evolution network.

[0039] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0040] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0041] The terminal service connection event may be a handover of a terminal from or to said first cell.

[0042] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal. [0043] The cell-specific information may comprise a slice identification.

[0044] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell. [0045] According to a fifth aspect, there is provided a method for a control plane function, the method comprising receiving, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

[0046] The method may further comprise using the cell-specific identification in response to the terminal service connection event to select a user plane function for a terminal.

[0047] The method may further comprise selecting a user plane function based at least on part on said cell-specific information.

[0048] The transmission may comprise an identification of a public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell in advance of a terminal service connection event involving said first cell, and the method may further comprise: receiving a service request from a terminal that identifies a mode supported by a cell and at least one logical network; and using said service request, identification of the public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell to select a user plane function for said terminal. [0049] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0050] The cell-specific indication of at least one mode may be an indication whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be a 5G network or a Long Term Evolution network.

[0051] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0052] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0053] The terminal service connection event may be a handover of a terminal from or to said first cell. [0054] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal. [0055] The cell-specific information may comprise a slice identification.

[0056] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[0057] According to a sixth aspect, there is provided a method for a user plane function, the method comprising transmitting, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

[0058] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0059] The cell-specific indication of at least one mode may be an indication whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be a 5G network or a Long Term Evolution network.

[0060] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0061] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0062] The terminal service connection event may be a handover of a terminal from or to said first cell.

[0063] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal.

[0064] The cell-specific information may comprise a slice identification. [0065] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[0066] According to a seventh aspect, there is provided an apparatus for a control plane function, the apparatus comprising receiving circuitry for receiving, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell. [0067] The apparatus may further comprise using circuitry for using the cell-specific identification in response to the terminal service connection event to select a user plane function for a terminal.

[0068] The apparatus may further comprise selecting circuitry for selecting a user plane function based at least on part on said cell-specific information. [0069] The transmission may comprise an identification of a public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell in advance of a terminal service connection event involving said first cell, and the apparatus further comprises: receiving circuitry for receiving a service request from a terminal that identifies a mode supported by a cell and at least one logical network; and using circuitry for using said service request, identification of the public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell to select a user plane function for said terminal.

[0070] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0071] The cell-specific indication of at least one mode may be an indication whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be a 5G network or a Long Term Evolution network.

[0072] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function. [0073] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0074] The terminal service connection event may be a handover of a terminal from or to said first cell.

[0075] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal.

[0076] The cell-specific information may comprise a slice identification.

[0077] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[0078] According to an eighth aspect, there is provided an apparatus for a user plane function, the apparatus comprising transmitting circuitry for transmitting, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

[0079] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0080] The cell-specific indication of at least one mode may be an indication whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be a 5G network or a Long Term Evolution network.

[0081] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0082] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0083] The terminal service connection event may be a handover of a terminal from or to said first cell. [0084] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal. [0085] The cell-specific information may comprise a slice identification.

[0086] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[0087] According to a ninth aspect, there is provided a computer program comprising program instructions for causing a computer to perform any method as described above.

[0088] According to a tenth aspect, there is provided a computer program product stored on a medium may cause an apparatus to perform any method as described herein. [0089] According to an eleventh aspect, there is provided an electronic device that may comprise apparatus as described herein.

[0090] According to a twelfth aspect, there is provided a chipset that may comprise an apparatus as described herein.

[0091] According to a thirteenth aspect, there is provided non-transitory computer readable medium comprising program instructions for causing an apparatus for a control plane function to perform at least the following: receive, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell. [0092] The apparatus may further be caused to use the cell-specific identification in response to the terminal service connection event to select a user plane function for a terminal.

[0093] The apparatus may further be caused to select a user plane function based at least on part on said cell-specific information. [0094] The transmission may comprise an identification of a public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell in advance of a terminal service connection event involving said first cell, and the apparatus may further be caused to: receive a service request from a terminal that identifies a mode supported by a cell and at least one logical network; and use said service request, identification of the public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell to select a user plane function for said terminal.

[0095] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[0096] The cell-specific indication of at least one mode may be an indication whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be a 5G network or a Long Term Evolution network.

[0097] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[0098] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[0099] The terminal service connection event may be a handover of a terminal from or to said first cell. [00100] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal.

[00101] The cell-specific information may comprise a slice identification. [00102] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

[00103] According to an fourteenth aspect, there is provided non-transitory computer readable medium comprising program instructions for causing an apparatus for a control plane function to perform at least the following: transmit, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell. [00104] The cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

[00105] The cell-specific indication of at least one mode may be an indication whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be a 5G network or a Long Term Evolution network. [00106] Said transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

[00107] Said transmission may provide an identification of a public land mobile network in which the cell-specific information is valid.

[00108] The terminal service connection event may be a handover of a terminal from or to said first cell. [00109] The terminal service connection event may be a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal.

[00110] The cell-specific information may comprise a slice identification. [00111] The information regarding a supported mode may indicate whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

Description of Figures [00112] Examples will now be described, by way of example only, with reference to the accompanying Figures in which:

[00113] Figure 1 shows a schematic diagram of an example communication system comprising a plurality of base stations and a plurality of communication devices; [00114] Figure 2 shows a schematic diagram of an example mobile communication device;

[00115] Figure 3 shows a schematic diagram of an example network element; [00116] Figures 4 to 6 show schematic diagrams of example communication networks;

[00117] Figure 7 is a flow chart of potential operations by a control plane function; and [00118] Figure 8 is a flow chart of potential operations by a user plane function.

Detailed description

[00119] In general, the following disclosure relates to a control plane function that receives cell-specific information from a user plane function about a cell in advance of a connection event involving that cell. For example, the connection event may be a user terminal switching from obtaining a service from that cell to obtaining the service from another cell. The control plane function may then use the received cell-specific information in response to the connection event happening. In particular, the information may be used for determining an appropriate new network configuration for providing the service to the user in a new cell.

[00120] A connection event may be caused and be effected in a variety of different ways. In general, it may refer to at least one terminal at least temporarily ceasing to receive or starting to receive at least one service from the cell associated with the cell-specific information. In other words, a connection event may, in the following, refer to both a terminal connecting to a cell and to a terminal disconnecting from a cell. This is because the information provided is useful for a connecting apparatus when accessing a cell (regardless of whether the cell supports 5G in standalone or non-standalone mode), when moving to a different cell, and when an ongoing user terminal connection is relocated due to a different cell needing to be accessed (e.g. due to load balancing or to a change in user applications/services, as described in the examples below).

[00121] For example, a static user terminal initially receiving a service through a first cell may reconnect to the service using a second cell. This may be triggered by the control plane function after the control plane function seeks to rebalance the network after the first cell becomes overloaded. At this time, multiple user terminals may be relocated to at least one other cell (such as the second cell).

[00122] As another example, a user terminal may be receiving a service through a first cell while moving relative to the boundaries of the first cell. In this case, the control plane function (either autonomously or in response to some instruction or request from another apparatus and/or function) may trigger a handover of the user terminal from the first cell to a second cell in order that the service may be continuously maintained. [00123] As another example, a user terminal may initially be receiving several services through a first cell before one of the services is terminated. The control plane function may determine that the remaining services being provided to the user terminal may be provided through a second cell (which did not support the dropped service). Consequently, the control plane function may cause the user terminal to be handed over from the first cell to the second cell.

[00124] Further features of this are discussed below in examples.

[00125] Before explaining in detail the examples, certain general principles of a wireless communication system and mobile communication devices are briefly explained with reference to Figures 1 to 2 to assist in understanding the technology underlying the described examples.

[00126] In a wireless communication system 100, such as that shown in figure 1, mobile communication devices, user apparatus, or terminal 102, 104, 105 are provided wireless access via at least one base station or similar wireless transmitting and/or receiving node or point. A user can access the communication system by means of an appropriate communication device or terminal. A communication device of a user is often referred to as user equipment (UE) or as a user apparatus. Throughout the following, these terms will be used interchangeably. It is understood that the term “terminal” is used to cover communication devices that may access a network through an access node, and which may or may not have a user. Examples of such terminals without a user include devices that make machine-to-machine transmissions in a factory. A communication device is provided with an appropriate signal receiving and transmitting apparatus for enabling communications, for example enabling access to a communication network or communications directly with other users. The communication device may access a carrier provided by a station or access node, and transmit and/or receive communications on the carrier.

[00127] The communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters which shall be used for the connection are also typically defined. One example of a communications system is UTRAN (3G radio). An example of attempts to solve the problems associated with the increased demands for capacity is an architecture that is known as the long-term evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. The LTE standard is developed by the 3rd Generation Partnership Project (3GPP). LTE was first released in 2008 (known as LTE Release 8), and new enhancements (in form of releases) has been introduced since then. LTE Release 13 and onwards is also known as LTE Advanced Pro. Another example of communications system is 5G system and New Radio (NR) radio interface, which is the latest 3GPP development.

[00128] A base station is referred to as an eNodeB (eNB) in LTE and as a gNodeB (gNB) in New Radio, and may be referred to more generally as simply a network apparatus or a network access node. Base stations are typically controlled by at least one appropriate controller apparatus, so as to enable operation thereof and management of mobile communication devices in communication with the base stations. The controller apparatus may be located in a radio access network (e.g. wireless communication system 100) or in a core network (CN) (not shown) and may be implemented as one central apparatus or its functionality may be distributed over several apparatus. The controller apparatus may be part of the base station and/or provided by a separate entity such as a Radio Network Controller. In Figure 1 control apparatus 108 and 109 are shown to control the respective macro level base stations 106 and 107. In some systems, the control apparatus may additionally or alternatively be provided in a radio network controller. [00129] 3GPP systems may however be considered to have a so-called “flat” architecture, without the provision of RNCs; rather the (e)/(g)NB is in communication with a system architecture evolution gateway (SAE-GW) and a mobility management entity (MME), which entities may also be pooled meaning that a plurality of these nodes may serve a plurality (set) of (e)/(g)NBs. Each user apparatus is served by only one MME and/or S-GW at a time and the (e)/(g)NB keeps track of current association. SAE-GW is a “high-level” user plane core network element in LTE, which may comprise the S-GW and the P-GW (serving gateway and packet data network gateway, respectively). The functionalities of the S-GW and P-GW are separated, and they are not required to be co-located. For 5G systems, in the 5G core the above- mentioned network entities are denoted User Plane Function (UPF) and Access and Mobility Management Function (AMF). The UPF is in charge of the user plane connectivity in the core and the AMF is in charge of access-related control plane functions in the core.

[00130] In a 3GPP system, radio resource control (RRC) is defined to be a sublayer of radio interface Layer 3 that exists in the control plane only, and which provides information transfer service to the non-access stratum (an example is provided in 3GPP Technical Specification Group Services and System Aspects 21.905). RRC is a protocol layer between a user apparatus and a base station, and is in charge of, for example, paging the user apparatus when traffic comes, establishing/maintaining or release of radio links (establishing an RRC connection between user apparatus and (e)/(g)NB), user apparatus mobility, user apparatus measurement configuration and user apparatus reporting configuration, etc. RRC is also responsible for controlling the configuration of radio interface Layers 1 and 2. [00131] In Figure 1 base stations 106 and 107 are shown as connected to a wider communications network 113 via gateway 112. A further gateway function may be provided to connect to another network.

[00132] The smaller base stations 116, 118 and 120 may also be connected to the network 113, for example by a separate gateway function and/or via the controllers of the macro level stations. The base stations 116, 118 and 120 may be pico or femto level base stations or the like. In the example, base stations 116 and 118 are connected via a gateway 111 whilst station 120 connects via the controller apparatus 108. In some examples, the smaller stations may not be provided. It is understood that this is just an example communication system, and other network structures may be defined by an operating communication protocol.

[00133] A possible mobile communication device will now be described in more detail with reference to Figure 2 showing a schematic, partially sectioned view of a communication device 200. Such a communication device is often referred to as user equipment, apparatus or terminal. An appropriate mobile communication device may be provided by any device capable of sending and receiving radio signals. Non-limiting examples comprise a mobile station (MS) or mobile device such as a mobile phone or what is known as a ’smart phone’, a computer provided with a wireless interface card or other wireless interface facility (e.g., USB dongle), personal data assistant (PDA) or a tablet provided with wireless communication capabilities, or any combinations of these or the like. Other non-limiting examples include apparatuses that may be used for Industrial Internet of things applications, such as, for example, smart robotics, assembly devices, warehouse-based devices, intelligent logistics, etc. A mobile communication device may provide, for example, communication of data for carrying communications such as voice, electronic mail (email), text message, multimedia and so on. Users may thus be offered and provided numerous services via their communication devices. Non-limiting examples of these services comprise two-way or multi-way calls, data communication or multimedia services or simply an access to a data communications network system, such as the Internet. Users may also be provided broadcast or multicast data. Non-limiting examples of the content comprise downloads, television and radio programs, videos, advertisements, various alerts and other information. It is understood that although a “mobile” communication device is referred to in the above and in the following, that the communication device may be stationary for extended periods of time.

[00134] The mobile device 200 may receive signals over an air or radio interface 207 via appropriate apparatus for receiving and may transmit signals via appropriate apparatus for transmitting radio signals. In Figure 2 transceiver apparatus is designated schematically by block 206. The transceiver apparatus 206 may be provided for example by means of a radio part and associated antenna arrangement. The antenna arrangement may be arranged internally or externally to the mobile device.

[00135] A mobile device is typically provided with at least one data processing entity 201 , at least one memory 202 and other possible components 203 for use in software and hardware aided execution of tasks it is designed to perform, including control of access to and communications with access systems and other communication devices. The data processing, storage and other relevant control apparatus can be provided on an appropriate circuit board and/or in chipsets. This feature is denoted by reference 204. The user may control the operation of the mobile device by means of a suitable user interface such as key pad 205, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 208, a speaker and a microphone can be also provided. Furthermore, a mobile communication device may comprise appropriate connectors (either wired or wireless) to other devices and/or for connecting external accessories, for example hands-free equipment, thereto. The communication devices 102, 104, 105 may access the communication system based on various access techniques. [00136] An example of wireless communication systems are architectures standardized by the 3rd Generation Partnership Project (3GPP). A latest 3GPP based development is often referred to as the 5th Generation (5G) New Radio (NR). Other examples of radio access system comprise those provided by base stations of systems that are based on technologies such as wireless local area network (WLAN) and/or WiMax (Worldwide Interoperability for Microwave Access). A base station can provide coverage for an entire cell or similar radio service area.

[00137] An example network equipment for the 3GPP system is shown in Figure 3. Figure 3 shows an example of a control apparatus 300 for a communication system, for example to be coupled to and/or for controlling a station of an access system, such as a radio access network node, e.g. a base station or (g) node B, or a node of a core network such as an MME or Access and Mobility Management Function (AMF). The method may be implanted in a single control apparatus or across more than one control apparatus. The control apparatus may be integrated with or external to a node or module of a core network or radio access network. In some examples, base stations comprise a separate control apparatus unit or module. In other examples, the control apparatus can be another network element such as a radio network controller or a spectrum controller. In some examples, each base station may have such a control apparatus as well as a control apparatus being provided in a radio network controller. The control apparatus 300 can be arranged to provide control on communications in the service area of the system. The control apparatus 300 comprises at least one memory 301 , at least one data processing unit 302, 303 and an input/output interface 304. Via the interface the control apparatus can be coupled to a receiver and a transmitter of the base station. The receiver and/or the transmitter may be implemented as a radio front end or a remote radio head. For example, the control apparatus 300 can be configured to execute an appropriate software code to provide the control functions. Control apparatus 300 may be included in a chipset or modem apparatus. A chipset or modem apparatus which includes apparatus 300 may be included in a control node such as a gNB. [00138] It is understood that although the example network element is shown as a single apparatus, that the functions of the network element may be split amongst several distinct apparatuses.

[00139] In particular, 3GPP specifications for 5G allow the functions of a gNB to be split up into a centralised unit (labelled as gNB-CU) and at least one distributed unit (labelled as a gNB-DU). The centralised unit may host the radio resource control (RRC) layer, the Service Data Adaptation Protocol (SDAP) layer, and the Packet Data Convergence Protocol (PDCP) Layer. The distributed unit may host the radio link control (RLC) layer, the Medium Access Control (MAC) layer, and the Physical (PHY) layer.

[00140] This is illustrated with respect to Figure 4 with respect to Integrated access and backhaul (IAB) architecture.

[00141] IAB is being investigated in 5G to realise backhaul links for relaying network access traffic. Previously, backhaul/fronthaul traffic was transmitted using a fixed/wired connection such as, for example, using fibres. In contrast, IAB utilises part of a wireless spectrum in order to provide a backhaul/fronthaul connection for the IAB nodes to base stations connected to the core network. Therefore, by avoiding a need for wired connections, the use of IAB may help to reduce deployment costs when setting up a communication network. This also means that there may be more mobility- related events in such networks as the specific area covered by each node changes. This can lead to more connection events, as described in the following.

[00142] Figure 4 shows a core network element 401 , three access points 402, 403, 404, each access point being communicatively coupled to a respective terminal(s) 405a, 405b, 405c. Centralised Unit functionality may be comprised within a gNB, but not within an IAB node. Consequently, access points 403 and 404 may be considered as IAB nodes. The access point 402 may be a gNB. Access point 402 is the only access point shown that has a backhaul connection 410 with the core network element 401 . Access point 402 is also shown as having interfaces to access points 403, 404 from a centralised unit 407. The centralised unit 407 may host the radio resource control (RRC) layer, the Service Data Adaptation Protocol (SDAP) layer, and the Packet Data Convergence Protocol (PDCP) Layer. Access point 402 also shows a distributed unit 406 that interfaces with a mobile termination part 411 of the access point 403 and terminal 405a. A mobile termination part is used by a mobile node to communicate with a parent node. This is in contrast with a distributed unit (such as 406, 408, 409 shown in Figure 4), which is used to communicate with a child node or a user terminal. Access point 403 comprises a distributed unit 408 that interfaces with a mobile termination part 412 of access point 504 and terminal 405b. Access point 404 comprises a distributed unit 409 that interfaces with terminal 405c. The distributed unit may host the radio link control (RLC) layer, the Medium Access Control (MAC) layer, and the Physical (PHY) layer.

[00143] Some 3GPP specifications also allow for network slicing. Network slicing is a type of virtual networking architecture that allows the creation of multiple virtual networks on top of a shared physical infrastructure. For example, control plane parts of a network and user plane parts of a network may be separated. This would enable user plane functionality to be deployed closer to an edge of a communication network (such as in access points), while management functions for the network may remain in the core network architecture. The virtual/logical networks are referred to as network slices. Network slices may be also be configured for specific use cases. For example, there may be an Internet of Things slice, a mobile broadband slice and a healthcare slice all operating the same network infrastructure. Therefore, network slices may be thought of an end-to-end logical network running on a common underlying network (virtual or physical) that are mutually isolated with independent control and management functions.

[00144] Interfaces between these entities support for effecting the radio access network (RAN) internal functional split are also defined in 3GPP specifications. For example, an F1 interface is defined between a control plane part of a gNB-CU and a gNB-DU. Further, an E1 interface is defined between a control plane part of a gNB- CU and a user plane part of a gNB-CU.

[00145] An illustration of these interfaces is illustrated with respect to Figure 5.

[00146] Figure 5 shows a control plane part of a CU-gNB 501 connected to multiple user plane parts of CU-gNBs 502a, 502b,... 502n via respective E1 interfaces 503a, 503b,... 503n. The control plane part of a CU-gNB 501 is also connected to multiple gNB-DUs 504a, 504b,... 504n via respective F1 (control part) interfaces 505a, 505b,... 505n. The user plane parts of CU-gNBs 502a, 502b,... 502n are also connected to the multiple gNB-DUs 504a, 504b,... 504n via respective F1 (user part) interfaces, which are shown as dashed lines extending from the user plane parts of CU-gNBs 502a, 502b,... 502n to the gNB-DUs 504a, 504b,... 504n in Figure 5. [00147] However, some of the implications of the current architecture of multiple gNB-DUs connected to multiple user plane part of a gNB-CUs have not been fully considered. This is because the user plane parts of the gNB-CUs (gNB-CU-UPs) may be offering different kinds of services for particular cells, and so not all services or slices are necessarily supported at each gNB-CU-UP for all of the cells and slices that it serves. There are thus some cases which may lead to mis-mapping at a user plane part of a gNB-CU and a control plane part of a gNB-CU, which may impact on cell configuration.

[00148] This problem becomes more apparent when multiple gNB-DUs are connected to multiple gNB-CU-UPs and/or when multiple gNB-CU-UPs provide different service types, such as, for example, enhanced mobile broadband services and ultra-reliable low-latency communication services. This is because the information that a gNB-CU-UP provides to a control part of the gNB-CU (gNB-CU-CP) relates to a total/cumulative amount of services for a cell. This is illustrated via Table 1, which shows some information elements included in an Έ1 setup request” message sent between a gNB-CU-UP to a gNB-CU-CP.

Table 1 - Information elements in an E1 setup request [00149] As can be seen from Table 1 , when a gNB-CU-UP requests an interface to be set up between itself and a gNB-CU-CP, it includes a list of supported public land mobile networks (PLMNs). This includes both a list of the types of virtual networks (slices) supported by the gNB-CU-UP and a list of the cells that the gNB-CU-UP supports (identified by, for example, a cell global identifier). A public land mobile network may be considered to be a combination of wireless communication services offered by a specific operator in a specific country.

[00150] A problem with this is illustrated with respect to the following example. [00151] First, we assume that there are 200 cell global identifiers (CGIs), labelled between 00 and 199, and three gNB-CU-UPs, each connected to multiple gNB-DUs. [00152] CGIs 00-49 are within an area that is served by a first gNB-CU-UP or a second gNB-CU-UP. These CGIs may comply with delay requirements for an ultra reliable low latency communication (URLLC) slice due to their location. Selection of an appropriate gNB-CU-UP may not be an issue for other types of slices (e.g. enhanced Mobile Broadband (eMBB) slice).

[00153] CGIs 50-99 are within an area that is served by the first gNB-CU-UP or a third gNB-CU-UP. These CGIs may comply with delay requirements for an ultra reliable low latency communication (URLLC) slice due to their location. Selection of an appropriate gNB-CU-UP may not be an issue for other types of slices (e.g. enhanced Mobile Broadband (eMBB) slice).

[00154] CGIs 00-99 are all standalone cells, support URLLC and eMBB slices, and serve a first PLMN.

[00155] CGIs 100-199 are non-standalone cells, do not have any supported slices defined and serve the first PLMN. [00156] The first gNB-CU-UP supports URLLC and eMBB by marking CGIs GO-

199 as being supported. This means that the first gNB-CU-UP guarantees a delay constraint required for URLLC service for the entire specified cell range.

[00157] The second gNB-CU-UP supports partial URLLC and full eMBB by marking CGIs 00-49 as supported with both URLLC and eMBB and CGIs 50-199 as being supported with eMBB. This means that the second gNB-CU-UP can only guarantee a delay constraint required for URLLC service for cells 00-49 (i.e. not guaranteed for cells 50-199). However, eMBB may be provided by the second gNB- CU-UP in any cell. [00158] The third gNB-CU-UP supports partial URLLC and full eMBB by marking CGIs 50-99 as supported with both URLLC and eMBB and CGIs 00-49 and 100-199 as being supported with eMBB. This means that the second gNB-CU-UP can only guarantee a delay constraint required for URLLC service for cells 50-99 (i.e. not guaranteed for cells 50-199). However, eMBB may be provided by the third gNB-CU- UP in any cell.

[00159] The above setup is illustrated with respect to Figure 6.

[00160] Figure 6 shows a virtual network function (VNF) cluster of cells 601 at a first location, providing CGIs 100-199. Cells 601 offer services that are not specific to any slice. Also shown is a VNF cluster of cells 602 at a second location. Cells 602 offer a first Industrial Internet of Things services, providing CGIs 00-49 for URLLC. Also shown is a VNF cluster of cells 603 at a third location. Cells 603 offer a second Industrial Internet of Things services, providing CGIs 50-99 for URLLC. The first gNB- CU-UP 604 may be located such that it may support URLLC in every cell. The second gNB-CU-UP 605 may be located such that it may support URLLC only in cells 00-49. The third gNB-CU-UP 606 may be located such that it may support URLLC only in cells 50-99.

[00161] Based on this example, the information provided by each of the gNB- CU-UPs to the gNB-CU-CP in an E1 setup request message is as follows. [00162] Under the “Supported PLMNs” section, the first gNB-CU-UP indicates a

“PLMN Identity” of PLMN1, a “Slice Support List” of URLLC and eMBB and a “CGI Support List” of 00-199.

[00163] Under the “Supported PLMNs” section, the second gNB-CU-UP indicates a “PLMN Identity” of PLMN1 , a “Slice Support List” of URLLC and eMBB and a “CGI Support List” of 00-199.

[00164] Under the “Supported PLMNs” section, the third gNB-CU-UP indicates a “PLMN Identity” of PLMN1, a “Slice Support List” of URLLC and eMBB and a “CGI Support List” of 00-199.

[00165] In other words, despite the different capabilities of the three gNB-CU- UPs with respect to URLLC support, the same information is provided by the gNB-CU- UPs to a gNB-CU-CP, which means that the gNB-CU-CP is unable to distinguish between their capabilities. In other words, a gNB-CU-CP cannot recognise what a gNB-CU-UP can support with respect to cells and services. [00166] This issue may become further complicated and worse when Radio Access Network sharing is supported (i.e. when there are multiple PLMNs). Moreover, load balancing and gNB-CU-UP selection algorithms employed by a gNB-CU-CP may end up choosing gNB-CU-UPs that cannot support the required services. This may lead to eventual rejection/bearer drop.

[00167] A similar issue relates to standalone and non-standalone cells. Standalone cells are cells that use a 5G deployments for both user plane functions and control plane functions. Non-standalone cells use a 5G deployment of the user plane functions, but may use a control plane function of an LTE network. [00168] In particular, it is not currently possible for a gNB-CU-CP to identify a gNB-CU-UP’s ability to support standalone and/or non-standalone mode for a particular cell served by it.

[00169] For example, assume that there are three gNB-CU-UPs (gNB-CU-UP1 , gNB-CU-UP2 and gNB-CU-UP3). The gNB-CU-UP1 is configured to support standalone mode but not non-standalone mode. The gNB-CU-UP2 is configured to support non-standalone mode but not standalone mode. The gNB-CU-UP3 is configured to support both standalone mode and non-standalone mode. It is further assumed that there are three gNB-DUs that are served by all the gNB-CU-UPs, but which are specific for the deployment that they are configured to support (e.g. standalone mode only, non-standalone mode only, or both standalone and non- standalone). It is understood that a gNB-CU-UP does not need to serve the entire set of gNB-DUs. Instead, a gNB-CU-UP may serve a subset of the entire set of gNB-DUs located within their geographic area.

[00170] Irrespective of which mode a particular gNB-CU-UP is configured to support, it would be useful for the gNB-CU-CP to know the list of cells that each gNB- CU-UP supports and their deployment capabilities. Therefore, gNB-CU-UP1 may indicate that it supports all three gNB-DUs for standalone mode only, gNB-CU-UP2 may indicate that it supports all three gNB-DUs for non-standalone mode only, and gNB-CU-UP3 may indicate that it may that is supports all three gNB-DUs for both standalone and non-standalone mode.

[00171] In order to address at least one of these issues, the following proposes a mechanism for indicating, for each cell/CGI, an indication of which slices are supported by that cell. [00172] This concept is illustrated with respect to Table 2.

Table 2 - Information elements in an E1 setup request

[00173] Table 2 differs from Table 1 in at least the following respects.

[00174] First, a new parameter set has been defined under “Supported PLMNs”. This parameter set is labelled as “Slices per NR CGI Support List” in Table 2. This may be indicated by a numeric value. The numeric value may have a maximum value of the number of CGIs in the communication network. The numeric value may have a minimum value of 1.

[00175] Within this new parameter set may be three parameters. These are described further below.

[00176] One of the parameters is labelled as “NR CGI”. This parameter provides an identification of the cell that is the subject of that parameter set.

[00177] Another of the parameters is labelled as “Slice support list”. This parameter provides an indication of the slices/virtual networks supported by the cell identified in “NR CGI”.

[00178] The third parameter is labelled “CN support”. This parameter provides a list of which core networks are supported by the cell identified in “NR CGI”. In other words, this parameter provides an indication of whether the cell is only configured to operate in only a standalone mode, in only a non-standalone mode, or in both standalone and non-standalone modes. This “CN support” parameter was previously provided at a “per gNB-CU-UP” level, and not at a cell level (see fourth row of Table 1 ). [00179] Having provided some specific examples, the following considers some more general principles behind the present application, with reference to Figure 7 and 8.

[00180] Figure 7 relates to operations performed by an apparatus for a control plane function. A control plane function may be considered to be a function of a communication network that carries signalling and that is responsible for selecting the routing entity (i.e. , the gNB-CU-UP) in which the user data will be routed through. [00181] At 701 , a control plane function receives, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a connection event involving said first cell.

[00182] The control plane function may use this cell-specific identification to select a user plane control function. For example, the selection may be made to select a user plane control function for establishing or de-establishing a bearer between the user plane function and a terminal involved in said connection event. [00183] The “transmission” may be made internally when the control plane function and the user plane function are collocated. However, it is understood that the “transmission” may be made in any way that causes the control plane function to access the first identification and the at least one cell-specific identification after the user plane function has determined to make this information available to the control plane function.

[00184] As previously discussed, a connection event may be caused and be effected in a variety of different ways. In general, it may refer to at least one terminal at least temporarily ceasing to receive or starting to receive at least one service from the cell associated with the cell-specific information. In other words, a connection event may, in the following, refer to both a terminal connecting to a cell and to a terminal disconnecting from a cell. This is because the information provided is useful for a connecting apparatus when accessing a cell (regardless of whether the cell supports 5G in standalone or non-standalone mode), when moving to a different cell, and when an ongoing user terminal connection is relocated due to a different cell needing to be accessed (e.g. due to load balancing or to a change in user applications/services, as described in the examples below).

[00185] For example, a static user terminal initially receiving a service through a first cell may reconnect to the service using a second cell. This may be triggered by the control plane function after the control plane function seeks to rebalance the network after the first cell becomes overloaded. At this time, multiple user terminals may be relocated to at least one other cell (such as the second cell).

[00186] As another example, a user terminal may be receiving a service through a first cell while moving relative to the boundaries of the first cell. In this case, the control plane function (either autonomously or in response to some instruction or request from another apparatus and/or function) may trigger a handover of the user terminal from the first cell to a second cell in order that the service may be continuously maintained. [00187] As another example, a user terminal may initially be receiving several services through a first cell before one of the services is terminated. The control plane function may determine that the remaining services being provided to the user terminal may be provided through a second cell (which did not support the dropped service). Consequently, the control plane function may cause the user terminal to be handed over from the first cell to the second cell.

[00188] The control plane function may then use this cell-specific identification in response to the connection event happening. The information may be used to determine whether or not the first cell is suitable for providing at least one service to a terminal that has newly entered an area served by the first cell. [00189] As one example, the case of a control plane function establishing a bearer is considered. This may be performed during initial access and/or during mobility-related events (e.g. handover).

[00190] In this case, the control plane function may receive information from a distributed unit over an F1 interface regarding what slices each cell supports, and may receive information from a user plane function regarding what cells and what slices are supported by that user plane function. The control plane part may need to select a user plane part for establishing a bearer and so uses the provided information to select a user plane function that can support both the indicated cell and also a particular slice. Other aspects, such as load, may also be considered during the selection. For example, if there are multiple user plane functions that have indicated support for the same cell and slice, the control plane function may select the user plane function of these multiple user plane functions that has the lowest load. [00191] As another example, the case of when relocation of a user plane function is required as a result of some non-mobility-related event (for example, in response to overload of a particular user plane function, for load balancing , and/or in response to a change in the slices used by a terminal).

[00192] In this case, the user plane function may receive information from a distributed unit over an F1 interface regarding what slices each cell supports, and may receive information from a user plane function regarding what cells and what slices are supported by that user plane function. The control plane function may determine that an ongoing connection needs to be placed in a different user plane function to that currently being used. This determination may be made in response to having received an overload or a high load report from a user plane function currently being used for that connection. This may be in response to the control plane part being informed that a user terminal that had multiple slices ongoing had deactivated at least one slice, this deactivation resulting in a user plane function currently being used for that connection no longer being an optimal user plane function for that user terminal. In this latter scenario, the control plane part may decide to relocate any remaining services in a different user plane function.

[00193] Figure 8 is a flow chart relating to operations that may be performed by a user plane function.

[00194] At 801 , the user plane function transmits, to a control plane function, a transmission comprising a first indication of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a connection event involving said first cell. The first cell may be a cell served by the user plane function.

[00195] As per the above, the “transmission” may be made internally when the control plane function and the user plane function are collocated. Flowever, it is understood that the “transmission” may be made in any way that causes the control plane function to access the first identification and the at least one cell-specific identification after the user plane function has determined to make this information available to the control plane function.

[00196] In both of the above-mentioned cases, the cell-specific indication of at least one logical network may be an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability. It is understood that these are merely examples of types of slices/logical networks, and that other types may be defined. For example, other logical networks/slices include massive Machine Type Communications (mMTC), vehicle-to-everything (V2X) networks, voice, and operator-defined slices. [00197] The cell-specific indication of at least one mode may be an indication whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type. The first network type may be a 5G network or a Long Term Evolution network. [00198] According to a possibility the cell-specific indication of at least one mode may be an indication of whether the first cell uses control plane functions of only a first network type, only a second network type, or any of the first and second network types depending on a current configuration. The first network type may be a 5G network and the second network type may be a Long Term Evolution network. Therefore, the user plane function may be able to indicate on a per-cell basis whether or not a particular cell is a standalone cell, a non-standalone cell, of a hybrid.

[00199] In a non-standalone mode, a radio resource control connection may use control plane functions present in LTE eNBs and 5G gNBs in a dual connectivity mode for throughput enhancements. In this case, a terminal may connect to a LTE core network. In a standalone mode, a radio resource control connection may use control plane functions present in 5G gNBs. In this case, a terminal may connect to a 5G core network.

[00200] In both of the above-mentioned cases, the transmission may be transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function. For example, the request may be a request to set up an E1 interface between the control plane function and the user plane function. However, it is understood that this is not the only time that the information can be provided, and it may be provided in response to an explicit request from the control plane function to the user plane function, and/or it may be pushed to the control plane function by the user plane function.

[00201] One example of when it would be useful for this information to be provided to the control plane function post-setup of the E1 interface is as follows. A user plane function may initially define a cell that was deployed as a standalone cell only. However, due to expansion on a macro level, an operator may cause the cell to be able to operate in either standalone mode or non-standalone mode (i.e. it is able to operate in both modes). This change in configuration of the cell from standalone only to both standalone and non-standalone should be propagated to the control plane function in order that the control plane function may use this information for network planning.

[00202] In the above, it is understood that the transmission may also provide an identification of a public land mobile network in which the cell-specific information is valid. [00203] It should be understood that each block of the flowchart of the Figures and any combination thereof may be implemented by various means or their combinations, such as hardware, software, firmware, one or more processors and/or circuitry.

[00204] It is noted that whilst examples have been described in relation to one example of a standalone 5G, similar principles may be applied in relation to other examples of standalone 3G, LTE or 5G networks. It should be noted that other examples may be based on other cellular technology other than LTE, NR or on variants of both. Therefore, although certain examples were described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, examples may be applied to any other suitable forms of communication systems than those illustrated and described herein.

[00205] It is also noted herein that while the above describes examples, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present claims. [00206] It should be understood that the apparatuses may comprise or be coupled to other units or modules etc., such as radio parts or radio heads, used in or for transmission and/or reception. Although the apparatuses have been described as one entity, different modules and memory may be implemented in one or more physical or logical entities.

[00207] In general, the various examples may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the described may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the claimed is not limited thereto. While various aspects of the claimed may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[00208] The examples of this disclosure may be implemented by computer software executable by a data processor of the mobile device, such as in the processor entity, or by hardware, or by a combination of software and hardware. Computer software or program, also called program product, including software routines, applets and/or macros, may be stored in any apparatus-readable data storage medium and they comprise program instructions to perform particular tasks. A computer program product may comprise one or more computer-executable components which, when the program is run, are configured to carry out examples. The one or more computer- executable components may be at least one software code or portions of it.

[00209] Further in this regard it should be noted that any blocks of the logic flow as in the Figures may represent program steps, or interconnected logic circuits, blocks and functions, or a combination of program steps and logic circuits, blocks and functions. The software may be stored on such physical media as memory chips, or memory blocks implemented within the processor, magnetic media such as hard disk or floppy disks, and optical media such as for example DVD and the data variants thereof, CD. The physical media is a non-transitory media. [00210] The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processors may be of any type suitable to the local technical environment, and may comprise one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASIC), FPGA, gate level circuits and processors based on multi core processor architecture, as non-limiting examples.

[00211] Examples of the above disclosures may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[00212] The foregoing description has provided by way of non-limiting examples a full and informative description of the exemplary example of this disclosure. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this disclosure will still fall within the scope of the appended claims.

Claims

1 . An apparatus for a control plane function, the apparatus comprising: means for receiving, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

2. An apparatus as claimed in claim 1, further comprising: means for using the cell-specific identification in response to the terminal connection event to select a user plane function for a terminal.

3. An apparatus as claimed in any preceding claim, further comprising means for selecting a user plane function based at least on part on said cell-specific information.

4. An apparatus as claimed in any preceding claim, wherein the transmission comprises an identification of a public land mobile network, said least one cell- specific identification of at least one logical network and said mode supported by said first cell in advance of a terminal service connection event involving said first cell, and wherein the apparatus further comprises: means for receiving a service request from a terminal that identifies a mode supported by a cell and at least one logical network; and means for using said service request, identification of the public land mobile network, said least one cell-specific identification of at least one logical network and said mode supported by said first cell to select a user plane function for said terminal.

5. An apparatus for a user plane function, the apparatus comprising: means for transmitting, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

6. An apparatus as claimed in any preceding claim, wherein the cell-specific indication of at least one logical network is an indication of at least one of enhanced mobile broadband capability and ultra-reliable low-latency communication capability.

7. An apparatus as claimed in any preceding claim, wherein the cell-specific indication of at least one mode is an indication of whether the first cell can operate in non-standalone mode of a first network type, standalone mode of the first network type, or either of the modes of the first network type.

8. An apparatus as claimed in claim 6, wherein the first network type is one of a 5G network and a Long Term Evolution network.

9. An apparatus as claimed in any preceding claim, wherein said transmission is transmitted to the control plane function as part of a request to set up an interface between the control plane function and the user plane function.

10. An apparatus as claimed in any preceding claim, wherein said transmission provides an identification of a public land mobile network in which the cell- specific information is valid.

11. An apparatus as claimed in any preceding claim, wherein the terminal service connection event is a handover of a terminal from or to said first cell.

12. An apparatus as claimed in any of claims 1 to 10, wherein the terminal service connection event is a terminal ceasing the use of at least one logical network previously used by the terminal or the terminal service connection event is a terminal seeking to use an additional logical network to those currently used by the terminal.

13. An apparatus as claimed in any preceding claim, wherein the cell-specific information comprises a slice identification.

14. An apparatus as claimed in any preceding claim, wherein the information regarding a supported mode indicates whether a cell is configured to operate as only a standalone cell, as only a non-standalone cell, or as any of a standalone cell and a non-standalone cell.

15. A method for a control plane function, the method comprising: receiving, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

16. A method for a user plane function, the method comprising: transmitting, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

17. A computer program product comprising computer code that, when executed by at least one processor of an apparatus, causes the apparatus to perform the steps of claim 15.

18. A computer program product comprising computer code that, when executed by at least one processor of an apparatus, causes the apparatus to perform the steps of claim 16.

19. An apparatus for a control plane function, the apparatus comprising: at least one processor; and at least one memory comprising computer code that, when run on the at least one processor, causes the apparatus to: receive, from a user plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.

20. An apparatus for a user plane function, the apparatus comprising: at least one processor; and at least one memory comprising computer code that, when run on the at least one processor, causes the apparatus to: transmit, to a control plane function, a transmission comprising a first identification of a first cell and at least one cell-specific identification of at least one logical network and/or mode supported by said first cell in advance of a terminal service connection event involving said first cell.