RRC Idle and inactive mode methods and apparatus

Abstract

A method of a network controlled repeater (NCR), configured to perform a forwarding function in a network, comprises: when camping on a first cell of the network, detecting a trigger for performing ce

Description

BACKGROUND Field Certain examples of the present disclosure relate to techniques fora repeater node in idle and / or inactive modes. For example, certain examples of the present disclosure provide methods, apparatus and systems for a Network Control Repeater (NCR) in a 3rd Generation Partnership Project (3GPP) 5th Generation (5G) New Radio (NR) network for Radio Resource Control (RRC) Idle mode and / or Inactive mode. Description of the Related Art The content of the following documents is referred to below and / or their content provides background information that the following disclosure should be considered in the context of: [1] 3GPP TS 38.304; 5G, NR, User Equipment (UE) procedures in idle mode and in RRC Inactive state; Release 17 (e.g., version 17.2.0) [2] 3GPP TS 23.501; 5G, system architecture for the 5G System (5GS); Release 17 (e.g., version 17.7.0) [3] 3GPP TS 38.300; 5G, NR, NR and NG-RAN Overall description; Stage-2; Release 17 (e.g., version 17.2.0) (Note: the example versions shown for each TS are non-limiting, other versions of the TS may be considered also) Wireless or mobile (cellular) communications networks in which a mobile terminal (e.g., user equipment (UE), such as a mobile handset) communicates via a radio link with a network of base stations, or other wireless access points or nodes, have undergone rapid development through a number of generations. The 3rd Generation Partnership Project (3GPP) design, specify and standardise technologies for mobile wireless communication networks. Fourth Generation (4G) and Fifth Generation (5G) systems are now widely deployed. 3GPP standards for 4G systems include an Evolved Packet Core (EPC) and an Enhanced-UTRAN (E-UTRAN: an Enhanced Universal Terrestrial Radio Access Network). The E-UTRAN uses Long Term Evolution (LTE) radio technology. LTE is commonly used to refer to the whole system including both the EPC and the EUTRAN, and LTE is used in this sense in the remainder of this document. LTE should also be taken to include LTE enhancements such as LTE Advanced and LTE Pro, which offer enhanced data rates compared to LTE. In 5G systems a new air interface has been developed, which may be referred to as 5G New Radio (5G NR) or simply NR. NR is designed to support the wide variety of services and use case scenarios envisaged for 5G networks, though builds upon established LTE technologies. New frameworks and architectures are also being developed as part of 5G networks in order to increase the range of functionality and use cases available through 5G networks. In order to provide enhanced network coverage, a variety of different types of network nodes have been developed. For example, a Radio Frequency (RF) repeater may be deployed to amplify and forward any signal that it receives to supplement coverage provided by a regular cell. An enhanced type of repeater node, called a Network-Controlled Repeater (NCR), is currently under development and is a Release 18 Study Item / Work Item (3GPP RP-213700). Figure 1 illustrates the network architecture of NCR communication. As shown, the NCR receives and forwards signals from a base station (e.g. a 5G NR base station, such as a gNB) to a target UE, User Equipment, via an NCR-Fwd link. The NCR also receives control signals from gNB via a control link, terminating at a NCR-Mobile Termination (MT) node. These control signals are used by the NCR-MT to configure the NCR. Once configured, the NCR provides an amplify-and-forward function (NCR-FWD) between the gNB (via backhaul link) and the UE (via access link) that is transparent to the UE. Accordingly, the gNB may communicate with the UE directly or through an NCR. The NCR-MT control link is intended to function similarly to a UE. Therefore, the NCR-MT has a full protocol stack to correspond to the UE control plane stack, and NCR configurations are signalled similarly to those for a UE. The NCR-MT may therefore be configured to search for serving cells, initiate and perform RRC signalling, transfer NCR capabilities, register to the network, and perform authentication. However, some functionality normally used by a UE may not be applicable to the NCR, and will not be implemented by NCR-MT and / or configured by the network. RRC protocol, as supported by the NCR, defines modes (or states) of behaviour for a UE according to resource: RRC_Connected, RRC_ldle and RRCJnactive. In RRC_Connected, the UE is assigned and communicating with a serving base station (e.g., gNB). In RRC_ldle, the UE is in a standby state and is not assigned to a serving base station. The UE camps on, that is, monitors a control channel of, a serving cell, wherein received incoming signals can be utilised during a cell reselection procedure. The UE can initiate RRC Connection establishment to the gNB and move from RRC_ldle to RRC_Connected. During RRC_lnactive, the gNB maintains the UE context, such that the UE does not need to be fully re-configured for re-connection to the gNB (RRC_Connected). Therefore the UE may move faster to RRC_Connected compared to RRC_idle, e.g. to perform data transmissions. This mechanism is enabled by the UE being configured with a RAN Notification Area (RNA). The UE may move freely within the same RNA without informing the network, and can perform RRC Connection Resume for mobile originated data to move to RRC Connected. Procedures, or state tasks, for a UE in either an idle or inactive mode (i.e., in RRCJdle or RRCJnactive), include: • PLMN or SNPN (network) selection, o For instance, a UE scans and reports detected PLMN to NAS. E.g., a PLMN is reported as a high quality PLMN if the measured RSRP value is greater than -110 dBm. • Cell selection and reselection, o For instance, a UE selects an (often initial) cell based on two criteria known as the Cell selection criteria. The UE selects a cell that fulfils the criteria, but it is not specified which of the cells that the UE shall select. The criteria are based on the received power level as well as the quality of the signal, which are in turn based on signaled thresholds and measurements. • Cell reselection, o For instance, cell reselection is for the UE to camp on the most suitable cell. In addition to the cell selection criteria, the UE also ranks different cells of the same priority to choose the best cell. The UE also measures on different frequencies that have either high or lower priority, which ensures that the UE always camps on the best cell with the highest priority. • Location registration, for instance: o Tracking Area registration - The UE reports the tracking area information to NAS, and if a UE camps on a new tracking area a Tracking Area Update is triggered. This may also be done periodically. Procedures (or state tasks) in the RRC_lnactive state include: o RAN Area Registration - The UE performs a RAN-based notification area update when the UE camps on a new cell that does not belong to the current RNA. This can also be done periodically. Thus, RNA update may be applicable only to the RRCJnactive state. An overview of procedure for a UE in RRC Idle mode is described by Figure 5.2.2-1, TS 38.304 [1]. As indicated, as the configurations of the NCR correspond to those of a UE, and the NCR supports RRC protocol, the NCR also supports RRC idle and RRC inactive modes. The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention. SUMMARY It is an aim of certain examples of the present disclosure to address, solve and / or mitigate, at least partly, at least one of the problems and / or disadvantages associated with the related art, for example at least one of the problems and / or disadvantages described herein. It is an aim of certain examples of the present disclosure to provide at least one advantage over the related art, for example at least one of the advantages described herein. The present invention is defined in the independent claims. Advantageous features are defined in the dependent claims. Embodiments or examples disclosed in the description and / or figures falling outside the scope of the claims are to be understood as examples useful for understanding the present invention. Other aspects, advantages and salient features of the invention will become apparent to those skilled in the art from the following detailed description taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 illustrates network architecture of NCR communication according to various examples of the present disclosure; Figure 2 is a flow diagram for an NCR configured to perform a forwarding function in a network according to various examples of the present disclosure; Figure 3 is a flow diagram for an NCR configured to perform a forwarding function in a network according to various examples of the present disclosure; Figure 4 is a flow diagram for reporting NCR presence of an NCR according to various examples of the present disclosure; Figure 5 is a diagram for reporting NCR presence according to various examples of the present disclosure; Figure 6 illustrates NCR-Specific tracking areas according to various examples of the present disclosure; Figure 7 is a flow diagram for configuring measurement relaxation of an NCR according to various examples of the present disclosure; Figure 8 is a flow diagram for configuring measurement relaxation of an NCR according to various examples of the present disclosure; Figure 9 is a block diagram of an exemplary network entity that may be used in certain examples of the present disclosure. DETAILED DESCRIPTION The following description of examples of the present disclosure, with reference to the accompanying drawings, is provided to assist in a comprehensive understanding of the present invention, as defined by the claims. The description includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the examples described herein can be made without departing from the scope of the invention. The same or similar components may be designated by the same or similar reference numerals, although they may be illustrated in different drawings. Detailed descriptions of techniques, structures, constructions, functions or processes known in the art may be omitted for clarity and conciseness, and to avoid obscuring the subject matter of the present invention. The terms and words used herein are not limited to the bibliographical or standard meanings, but, are merely used to enable a clear and consistent understanding of the invention. Throughout the description and claims of this specification, the words “comprise”, “include” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other features, elements, components, integers, steps, processes, operations, functions, characteristics, properties and / or groups thereof. Throughout the description and claims of this specification, the singular form, for example “a”, “an” and “the”, encompasses the plural unless the context otherwise requires. For example, reference to “an object” includes reference to one or more of such objects. Throughout the description and claims of this specification, language in the general form of “X for Y” (where Y is some action, process, operation, function, activity or step and X is some means for carrying out that action, process, operation, function, activity or step) encompasses means X adapted, configured or arranged specifically, but not necessarily exclusively, to do Y. Features, elements, components, integers, steps, processes, operations, functions, characteristics, properties and / or groups thereof described or disclosed in conjunction with a particular aspect, embodiment, example or claim are to be understood to be applicable to any other aspect, embodiment, example or claim described herein unless incompatible therewith. The skilled person will appreciate that the techniques described herein may be used in any suitable combination. Certain examples of the present disclosure provide methods, apparatus and systems for performing random access to a network. For example, certain examples of the present disclosure provide methods, apparatus and systems for performing random access to a 3GPP 5G NR network including an NCR. However, the skilled person will appreciate that the present invention is not limited to these examples, and may be applied in any suitable system or standard, for example one or more existing and / or future generation wireless communication systems or standards, including any existing or future releases of the same standards specification, for example 3GPP 5G. The following examples are applicable to, and use terminology associated with, 3GPP 5G. However, the skilled person will appreciate that the techniques disclosed herein are not limited to 3GPP 5G. For example, the functionality of the various network entities and other features disclosed herein may be applied to corresponding or equivalent entities or features in other communication systems or standards. Corresponding or equivalent entities or features may be regarded as entities or features that perform the same or similar role, function or purpose within the network. A particular network entity may be implemented as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, and / or as a virtualised function instantiated on an appropriate platform, e.g., on a cloud infrastructure. Certain examples of the present disclosure may be provided in the form of an apparatus / device / network entity configured to perform one or more defined network functions and / or a method therefor. Certain examples of the present disclosure may be provided in the form of a system (e.g. network or wireless communication system) comprising one or more such apparatuses / devices / network entities, and / or a method therefor. At least the following problems exist in view of the related art: As for a UE, the NCR-MT may support configuration in RRC_Connected mode, RRCJnactive mode, and / or RRCJdle mode. Therefore cell reselection, and RRM measurements, may be supported fora NCR. In particular: • 1 / 1 / / 76 / 7 NCR-MT is in RRC_Connected mode, the NCR-Fwd can be on or off following side control information received from the gNB; • After NCR-MT enters RRC_lnactive mode, the NCR_Fwd can be On or OFF following the last configuration received from the gNB; • Release to RRCJdle is FFS (for further study) • NCR-MT mandatorily supports cell reselection and RRM measurements in RRC_ldle and RRC_lnactive; • In Release 18, NCR-MT does not support handover and RRM measurements in RRC_CONNECTED. During deployment of an NCR, a control link is needed between the NCR (i.e., terminating at NCR-MT) and the gNB in order to control the NCR transmissions. When the UE connects to an NCR rather than a gNB, the connection (i.e. forwarding function NCR-Fwd) is intended to be transparent to the UE, such that it is unaware of the communication via NCR. However, whilst similarly configured, the reasoning and operation for the NCR performing idle or inactive mode procedures may be different to that of a UE. In particular, whilst NCR supports cell reselection procedure, and RRM measurements, NCR-specific problems may arise. For example, the problem may arise that NCR reselects to a cell (i.e., NCR-MT is camping on a reselected cell) different to the forwarding signals (i.e. a cell where NCR-Fwd is configured to signal from gNB to UE). Furthermore, during cell reselection procedure, a network entity (e.g. gNB, or other network entity) may be unaware of the presence of the NCR. Accordingly, there is a need to consider the operation of the NCR device, and configuration of the NCR-Fwd link, during RRC Idle and Inactive modes. In addition, there is a need to consider techniques for reporting presence of the NCR following cell reselection. Accordingly, certain examples of the present disclosure provide one or more techniques for configuration of a repeater node, such as an NCR, or of a forwarding function, such as the NCR-Fwd function, when operating in idle or inactive mode. Other examples of the present disclosure provide one or more techniques for configuration relating to cell reselection according to the state of the forwarding function, such as the NCR-Fwd function. Certain examples of the present disclosure relate to one or more techniques for performing measurement relaxation for cell selection by a repeater node, such as the NCR. Further examples relate to methods for reporting presence of a repeater node, such as the NCR, on or to a cell. Herein, NCR and gNB may be referred to as different network elements, entities and / or nodes. That is, the skilled person will appreciate that the techniques described herein may be applied to network elements, entities and / or nodes other than NCR and gNB. Certain examples of the present disclosure provide a method (and corresponding apparatus and / or system(s)), of a repeater node (e.g. NCR) configured to perform a forwarding function in a network, the method comprising: when camping on a first cell of the network, detecting a trigger for performing cell reselection; in response to a second cell being selected during the cell reselection, camping on the second cell, and modifying the forwarding function. In certain examples, when performing the cell reselection, the method may further comprise identifying, based on at least one cell selection criterion, the second cell to not be a suitable cell based on at least one cell selection criterion. In certain examples, the detected trigger may be a trigger for performing a network re-selection, and the second cell may be located in a second network different to the network of the first cell. In certain examples, when the detected trigger is a trigger for performing a network re-selection, and the method may further comprise receiving a signal rejecting a selected network during the network re-selection. In certain examples, when the detected trigger is a trigger for performing a network re-selection, the method further comprises receiving a signal accepting a selected network during the network re-selection. In certain examples, the method may further comprise modifying the forwarding function comprises changing the forwarding function from an on state to an off state. In certain examples, the off state may comprise: preventing a state in which the repeater node forwards data; or forwarding configuration of the repeater node is discarded; and / or a default forwarding configuration is applied. In certain examples, the on state may comprise one of: performing the forwarding function for all signals; performing the forwarding function selected signals; performing the forwarding function for specific transmissions received from a network entity controlling the first cell; and performing the forwarding function on specific transmissions by the repeater node. In certain examples the first cell may be selected as the second cell. Certain examples provide a method of a repeater node (e.g. NCR) configured to perform a forwarding function in a network, the method comprising: camping on a cell in the network; and whilst the forwarding function (e.g. NCR-Fwd) is on:configuring to turn off cell reselection whilst keeping the forwarding function on; or performing cell reselection based on modified cell reselection parameters in response to detecting a trigger for performing cell reselection. In certain examples, the modified cell reselection parameters may be received in system information, or a RRC message. In certain examples, the modified cell reselection parameters may be met for a configured period of time. In certain examples, the modified cell reselection parameters may be at least one of: Qrxlevmin; Qrlevminoffset; Pcompensation; QoffsetTemp; Qqualmin; Qqualminoffset. In certain examples, the cell reselection may be turned off for a configured period of time. In certain examples, the configured period of time may be one of: a signalled or pre-configured time duration following turning on of the forwarding function; a period of time until the forwarding function changes to off; and until a cell selection criterion is met. Certain examples of the present disclosure provide a repeater node (e.g. NCR) for reporting presence, the method comprising: when camping on a first cell of a network, detecting a trigger for performing cell reselection; performing cell reselection to select a second cell to camp on; camping on the selected second cell; and transmitting a message reporting presence of the repeater node on the selected second cell to a network entity (e.g. gNB) controlling the selected second cell. In certain examples, transmitting the message may comprise: reporting presence of the repeater node periodically to the controlling network entity; and / or reporting presence based on receiving a signal from another entity. In certain examples, the reporting presence of the repeater node may be performed using RRC signalling. In certain examples, the reporting presence of the repeater node on the selected cell to the network entity may trigger the network entity to notify another network entity controlling the first cell of the presence of the repeater node. In certain examples, the network entity is a base station (e.g., a 5G NR base station, e.g., a gNB). Certain examples of the present disclosure provide a method of a repeater node (e.g., NCR) for reporting presence, comprising: when camping on a first cell of a network, detecting a trigger for performing cell reselection; performing cell reselection to select a second cell to camp on; camping on the selected second cell; determining the repeater node to be in a new location area different to a location area of the first cell; and transmitting a message reporting presence of the repeater node in the new location area to a network entity. In certain examples, the location area may be one of a tracking area or a notification area. In certain examples, the method further comprises transmitting a message reporting presence of the repeater node on the selected second cell to a network entity controlling the selected second cell. Certain examples of the present disclosure provide a method of a repeater node (e.g., a NCR) for configuring measurement relaxation, comprising, while the repeater node is operating in an idle or inactive mode in which measurement relaxation is instructed by a network entity, one of: performing measurement relating to cell reselection by the repeater node without applying measurement relaxation; or determining whether a forwarding function of the repeater node is on, and performing measurement relating to cell reselection by the repeater node based on the determination. In certain examples, performing measurement based on the determination may further comprise: if the forwarding function of the repeater node is off, performing measurement relating to cell reselection without configuring measurement relaxation parameters; or if the forwarding function of the repeater node is on, performing measurement relating to cell reselection by configuring measurement relaxation parameters. Certain examples of the present disclosure provide an apparatus (e.g., a NCR) for performing a forwarding function in a network, the apparatus being configured to perform the method according to any aspect, example, claim or embodiment described herein. Certain examples of the present disclosure provide an apparatus (e.g., a NCR) being configured to perform the method according to any aspect, example, claim or embodiment described herein. Certain examples of the present disclosure provide an apparatus (e.g., a NCR) for configuring measurement relaxation, the apparatus being configured to perform the method according to any aspect, example, claim or embodiment described herein. Certain examples of the present disclosure provide a computer program comprising instructions which, when the program is executed by a computer or processor, cause the computer or processor to carry out a method according to any aspect, example, claim or embodiment described herein. Certain examples of the present disclosure provide a method of a network entity (e.g. gNB) controlling a first cell in a network, comprising: receiving notification of a repeater node camping on the first cell; in response to the notification, notifying another network entity of the presence of the repeater node on the first cell, the other network entity controlling a second cell on which the repeater node camped prior to the first cell. In certain examples, the received notification of the repeater node camping on the first cell may be performed using RRC signalling. Certain examples of the present disclosure provide a network entity controlling a first cell in a network, the network entity being configured to perform the above-example method. With reference to the present disclosure, the NCR-Fwd of the NCR (i.e., a forwarding function of a repeater node) will be defined as either ON or OFF; i.e., operating, or configured to operate, in either an ON state or an OFF state. In various examples, an ON state of the NCR is intended to define a state of forwarding, or being configured to perform a forwarding function for, signals between a base station (e.g. gNB) to a target UE. In some examples, when operating in the ON state, the NCR-Fwd may forward all signals from the gNB to the UE. In some examples, it may forward only selected signals. Information on selected signals to forward may be received via signalling, or instruction from a network entity etc. In another example, based on a connected Donor gNB, the NCR may forward the full bandwidth of the donor gNB, which is known from knowing what frequencies the donor gNB operates on. In some examples, the NCR-Fwd operating in the ON state may be configured to forward signals received on specific transmissions from the gNB; and / or forward signals to the UE on specific transmissions generated by the NCR-Fwd. These transmissions may be one or more beams, for example, each having one or more allocated SIB index. In other examples, the specific transmissions may refer to a set of allocated SIB indices. Similarly, in various examples of the present disclosure, where NCR-Fwd is described as being OFF, or in an OFF state, this defines a state of the NCR not forwarding, or not currently being configured to perform a forwarding function, for signals between a base station (e.g. gNB) and a target UE. In some examples, the NCR-FWD is turned off, such that it is not configured to, and / or does not provide, any forwarding of signals to the UE. In some examples, the NCR-Fwd in an OFF state refers to any state or configuration related to NCR-Fwd being in an off state. The NCR-Fwd being in an OFF state may indicate that the NCR-Fwd does not forward anything, or that the forwarding configuration is discarded and / or a default forwarding configuration is applied. For example, said forwarding configuration may refer to beam information, which indicates slot and / or indices information, for signal transmission. Figure 2 illustrates a flowchart of a method of a repeater node (e.g. an NCR) performing a forwarding function. For example, the method of Figure 2 may be performed by an NCR as described with reference to Figure 1, wherein the NCR performs a forwarding function (e.g. via NCR-Fwd) from a base station (e.g. gNB) to a UE. As described, the NCR-Fwd function may be configured in accordance with control signals received from gNB via a control link to NCR-Mobile Termination (MT) (NCR-MT). It will be appreciated that one or more of the operations shown in Fig. 2 may be omitted, replaced and / or re-ordered, thereby providing additional examples of the present disclosure. In first step 201, the NCR is in an idle mode or inactive mode (i.e. RRC_ldle, or RRC_lnactive) and camping on a first cell (e.g., Cell#1) of a network. In some examples, the first cell may be an initial cell, that is, a cell of the an initially selected network that fulfils cell selection criteria. Whilst camping (i.e., monitoring the control channel) on this first (serving) cell, the NCR-MT, through the control link, is configured to receive signals from a base station (e.g. gNB) controlling this first cell. In this example, NCR-Fwd is configured in an ON state, in that it is providing (or configured to provide) a forwarding function on NCR-Fwd to a target UE of the network. At step 203, the NCR may receive or detect a trigger (e.g., the NCR may be triggered) for performing a cell reselection (e.g., the NCR may detect a situation in which to reselect cell). Any suitable trigger by which a cell (or network) reselection may be used in various examples of the present disclosure. Some non-limiting examples will be described below. In an example, to determine that a trigger for cell reselection when in an idle (or inactive) state may be in response to cell reselection criteria being met. Such cell reselection criteria may be based on measurements of serving and neighbouring cells performed by the NCR. When the performed measurements (e.g., measurement parameters) meet a cell reselection criteria (e.g., a cell reselection trigger, for example, based on cell ranking) the cell reselection procedure is triggered at step 205. At step 205, during the cell reselection procedure, the NCR may determine, or detect / identify, a different cell, and subsequently may determine to camp on this cell. In various examples, a suitable cell may be determined or selected in view of criteria specified in TS 38.304 [1], e.g., referring to the definition of a suitable cell found therein. In some examples, as indicated in the example of Figure 2, a / the reselected cell may be determined as the first cell, i.e. that the NCR remains camped on the first cell or is considered to reselect to the first cell. This may arise if no suitable cell is found during cell-reselection (for example, if the cell selection criteria are not met, and / or a gNB of a cell is not NCR-capable). In the example where the NCR remains on the first cell in response to a cell reselection procedure being triggered, the NCR-Fwd may be modified from an ON to an OFF state. This may prevent NCR-Fwd from forwarding (or continuing to forward) signals to the UE when there is an insufficient connection to a base station (e.g. gNB) controlling the first cell of the network. In further examples, when performing the cell reselection procedure, the NCR may determine another cell as a better cell to camp on. For example, at step 207, the NCR may determine Cell#2 as a better cell to camp on, and the NCR may reselect to camp on this cell. When a different (i.e., another) cell to the first cell is selected during the cell reselection procedure, the NCR-Fwd may be modified from an initial ON state to an OFF state. In the above example, the NCR-Fwd is modified from an ON to an OFF state in response to a cell being selected during the cell reselection procedure (e.g. following step 205). In other examples, the NCR-Fwd may be modified from an ON to an OFF state in response to a cell reselection trigger being received (i.e. step 203). In some of the above examples, the NCR may be configured to modify NCR-Fwd based on actions performed by the NCR-MT. By modifying the NCR-Fwd from an ON state into an OFF state in response to cell reselection, or triggering of cell reselection, a problem where the NCR-MT is camping on the second (reselected) cell whilst NCR-Fwd is performing a forwarding function from a controlling gNB to the UE of the first cell may be resolved or mitigated. In further examples, the detected trigger (i.e. trigger 203 as show in Figure 2) may be a trigger for performing a network (e.g. PLMN) reselection. The trigger for network reselection can be triggered over the Non Access Stratum (NAS), e.g., based on any type of suitable procedure. It is apparent that any suitable trigger may be used here by which network (e.g. PLMN) selection may be triggered. In non-limiting examples, PLMN selection may be triggered by NAS when powering on the wireless device or when ordered by the Core Network in response to receiving a request. In an example, and following detection of the trigger for network reselection, the NCR may receive a signal over the NAS from an external network entity for accepting or rejecting the selected network. If this signal indicates that the reselected network is rejected, the NCR may remain on the first cell (e.g., Cell#1), and, in some examples, NCR-Fwd may be modified from an ON to an OFF state. If this signal indicates that the reselected network is accepted, the NCR may select a new initial cell of the accepted network (i.e., a cell reselection procedure is performed ), and may camp on this new (i.e. selected) cell. In response to reselecting to camp on this cell, NCR-Fwd may be modified from an ON to an OFF state (e.g., at step 207 of Figure 2). In other examples, NCR-Fwd may be modified from an ON to an OFF state on receipt of the trigger for performing a network reselection, and in further examples, in response to receipt of the signal accepting the selected network (i.e., prior to network change). Figure 3 is a flowchart of a further method of a repeater node (e.g. an NCR) performing a forwarding function in a network, according to an example of the present disclosure. In this example, and similarly to Figure 2, the method of Figure 3 may performed by an NCR as described with reference to Figure 1. It will be appreciated that one or more of the operations shown in Fig. 3 may be omitted, replaced and / or re-ordered, thereby providing additional examples of the present disclosure. At first step 301, NCR may be in an idle or inactive mode (e.g., RRCJdle or RRC_lnactive) and camping (or monitoring) a first cell (e.g., Cell#1) of a network, and the NCR-Fwd is operating in an ON state. That is, the NCR-Fwd may be performing a forwarding function for signals from a controlling base station (e.g., gNB) of the first cell to a UE in the network. In an example, whilst the NCR-Fwd is determined to be in the ON state, the NCR may be configured to turn off cell reselection, at step 303. In other words, the NCR-Fwd remains ON, but procedure for cell reselection is not performed, even if a trigger, such as described with reference to step 203 of Figure 2, is received or detected. This may prevent the situation where NCR-MT may reselect to camp on a different cell from a gNB providing data to be forwarded via the NCR-Fwd function. Turning off cell reselection may ensure that the NCR stays with the donor gNB (e.g., gNB of the first cell) and does not camp on a different cell. In some examples, turning off cell reselection comprises that all cell reselection operations are turned off for the duration of NCR-Fwd being in an ON state. In other examples, the cell reselection procedure may be turned off fora configured amount of time. The configured amount of time may be at least one of: a signalled or pre-configured time duration following NCR-Fwd being configured in (or turned to) an ON state; a period of time until NCR-Fwd changes to an OFF state; or until a cell reselection criterion (i.e. based on a cell ranking) is met. The cell selection criterion may correspond to the criterion being fulfilled as detailed in TS 38.304 [1] (e.g., refer to clause 5.2.3.2), in respect of a UE, as based on a combination of two conditions: Srxlev >0 AND Squal >0 That is, 1) received signal level is above threshold, and 2) received signal quality is above a threshold, and where: Srxlev = Qrxlevmeas - (Qrxlevmin + Qrxlevminoffset)- Pcompensation - Qoffsettemp Squal = Qqualmeas - (Qqualmin + Qqualminoffset) - Qoffsettemp These terms are defined in TS 38.304 [1] (§5.2.3.2) as follows: Srxlev Cell selection RX level value (dB) Squal Cell selection quality value (dB) QoffS©ttemp Offset temporarily applied to a cell as specified in TS 38.331 [3] (dB) Qrxlevmeas Measured cell RX level value (RSRP) Qqualmeas Measured cell quality value (RSRQ) Qrxlevmin Minimum required RX level in the cell (dBm). If the UE supports SUL frequency for this cell, Qrxievmin is obtained from q-RxLevMinSUL, if present, in SIB1, SIB2and SIB4, additionally, if QrxievminotftetceiisuL is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell; else Qrxievmin is obtained from q-RxLevMin in SIB1, SIB2 and SIB4, additionally, if Qrxievminoffsetceii is present in SIB3 and SIB4 for the concerned cell, this cell specific offset is added to the corresponding Qrxlevmin to achieve the required minimum RX level in the concerned cell. Qqualmin Minimum required quality level in the cell (dB). Additionally, if Qquaiminoffsetceii is signalled for the concerned cell, this cell specific offset is added to achieve the required minimum quality level in the concerned cell. Qixlevminoffset Offset to the signalled Qrxievmin taken into account in the Srxlev evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN, as specified in TS 23.122 [9], Qqualminoffset Offset to the signalled Qquaimin taken into account in the Squal evaluation as a result of a periodic search for a higher priority PLMN while camped normally in a VPLMN, as specified in TS 23.122 [9], P compensation For FR1, if the UE supports the additionalPmax in the NR-NS-PmaxList, if present, in SIB1, SIB2 and SIB4: max(PEMAX1 —PpowerClass, 0) - (mln(PEMAX2, PpowerClass) -min(PEMA.X1, PpowerClass)) (dB)^ else: max(PEMAX1 ~PpowerClass, 0) (dB) For FR2, Pcompensation iS Set tO 0. For IAB-MT, Pcompensation IS Set tO 0. However, in some examples, the cell selection criterion or cell-ranking may be fulfilled by conditions that are set differently for a NCR. In particular, the NCR may be configured with modified, or NCR-specific parameters, as will be discussed below. Referring back to Figure 3, and step 301, the NCR is camping on the first cell and NCR-Fwd is in an ON state. At step 305, as an alternative example to step 303, whilst the NCR-Fwd is determined to be in an ON state, the NCR may configured with modified parameters for performing cell reselection procedure. In other words, the cell reselection criterion is fulfilled by different (e.g., NCR-Specific) threshold parameters in comparison to UE parameters. These NCR-specific parameters may include at least the following parameters: Qrxlevmin; Qrlevminoffset; Pcompensation; QoffsetTemp; Qqualmin; Qqualminoffset, contributing to the cell selection criteria conditions Srxlev and Squal, as detailed above. In some examples, these parameters may be signalled in broadcast system information, over system information block(s), SIB(s), such asSIBI, SIB2, SIB3, orSIB4. In other examples, these parameters may be signalled in RRC messages. The NCR may be configured to perform cell reselection procedure only when the cell selection criterion or cell-ranking criterion, as based on NCR-specific parameters, are fulfilled for more than a certain amount of time or are fulfilled within a period of time (e.g., a specified period). In an example, this may be in a range of seconds, e.g., from 1 to 100 seconds: {1, 2, 5, 10, 15, 25, 50, 100}. This time may be configured and / or signalled in addition to, or separate to, the NCR-specific parameters, as detailed above. In other examples, this amount of time may be pre-configured at the NCR. In an example, the cell reselection procedure may be performed according to the modified parameters, at step 305. At step 307, the NCR may reselect to camp on a different cell (e.g., Cell #2, being a suitable cell (or, if necessary, an acceptable cell)), and NCR-Fwd may be turned off (corresponding to step 207 of Figure 2). In another example, Cell#1 may be selected at step 305, and the NCR may select (e.g., remain) camping on the same cell (Cell #1), and NCR-Fwd may be modified from an ON to an OFF state. According to the above-detailed examples, by configuring the cell reselection criteria of the NCR, the NCR device (e.g., NCR-MT) is discouraged from camping on another cell whilst NCR-Fwd is on. Figure 4 is a flowchart of a further method of a repeater node (e.g. an NCR) reporting presence according to an example of the present disclosure. For example, when camping on a new cell (i.e. following cell reselection), the network (and a controlling network entity) may be unaware of the presence of the NCR on the cell. The NCR may be configured to establish a connection (i.e. with the gNB) and report when camping on a new cell. It will be appreciated that one or more of the operations shown in Fig. 4 may be omitted, replaced and / or re-ordered, thereby providing additional examples of the present disclosure. It will further be appreciated how, in various examples of the present disclosure, the method of Fig. 4 may be combined with another method disclosed herein, such as that of Fig. 2 or Fig. 3. Referring to Figure 4, in step 401, the NCR may camp on a first cell (e.g., Cell#1). The NCR may be in either Idle or Inactive mode (e.g., RRC_ldle, RRC_lnactive). In the example shown in Figure 4, the forwarding function (NCR-Fwd) may either be in either an ON or OFF state. In some examples, whilst the NCR remains camping on this first cell (Cell#1), the NCR may periodically report its presence to a network entity (e.g., the gNB controlling the cell). At step 403, a cell reselection trigger may be received or detected. Any suitable trigger may be used or described, and may herein be defined similarly to cell reselection trigger 203 with reference to Figure 2. Following receipt of this trigger, the NCR may proceed to a cell reselection procedure at step 405. The NCR may reselect cell to camp on either a different cell at step 407, and in other examples, may select to remain on the same cell as a result of performing cell reselection. In some examples, the NCR may report its presence to the gNB (of the first cell) to indicate that it remains camping on the first cell. For example, the NCR may continue to periodically report its presence whilst it remains camping on the first cell. In various examples, when the second cell is selected at step 407, the NCR reselects cell to camp on the second cell (Cell #2). Subsequently, at step 409, the NCR may transmit a message reporting presence of the NCR on this second cell to a network entity (e.g. gNB) controlling the second cell. The message may be transmitted in response to starting camping on the second cell, i.e. on / following connection to the second cell. In other examples, the NCR may periodically report presence on the second cell to the controlling gNB (e.g., NCR reports presence after camping on second cell according to the timing of the periodic reporting, e.g., on a reporting occasion). In other examples, the NCR may report presence to the gNB when receiving a signal from another entity. For example, the NCR may be turned off, but monitoring activity from another network entity, and the NCR may transmit a message indicating presence on the second cell on detection of said entity. In some examples, the reporting presence of the repeater node in any of the above examples, is performed using RRC signalling. In examples, this can be done through the NCR performing RRC Connection establishment procedure (RRCSetupRequest- RRCSetup-RRCSetupComplete). In examples, it can also be performed through the RRC Resume procedure (RRCResumeRequest - RRCResume- RRCResumeComplete). In examples, the NCR presence update can be done through indicating that the NCR device is updating its presence in any of the RRC connection establishment request message - i.e. RRCSetupRequest, RRCResumeRequest, RRCConnectionEstablishmentRequest, or RRCConnectionResumeRequest. It will be appreciated that various examples of the present disclosure also include a network entity (e.g., a base station, such as a gNB) which is configured to operate according to the method of Fig. 4, in the sense of relating to the base station controlling the first cell or the base station controlling the second cell. For example, various examples relate to a network entity configured to receive an indication that a NCR (i.e., repeater node) is camped on a cell controlled by the network entity, following cell reselection by the NCR. Optionally, the network entity may report presence of the NCR on the cell controlled by the network entity to another network entity which controls a cell on which the NCR was previously camping. In various embodiments of the present disclosure, an NCR may be configured to periodically report presence to a network entity, such as a network entity controlling a cell on which the NCR has camped on. For example, reporting presence is not triggered (or not exclusively triggered by) cell or network (e.g., PLMN) reselection, but rather the NCR is configured to periodically report presence on a cell such that a gNB, for example, controlling the cell will (i.e., eventually) be informed of the presence of the NCR on that cell. Referring Figure 5, this illustrates an further example for reporting presence of a repeater node (e.g. NCR). It will be appreciated that one or more of the operations shown in Fig. 5 may be omitted, replaced and / or re-ordered, thereby providing additional examples of the present disclosure. It will further be appreciated how, in various examples of the present disclosure, the method of Fig. 5 may be combined with another method disclosed herein, such as that of Fig. 2 or Fig. 3. The NCR 520 may be in either an idle or inactive mode (e.g., RRCJdle or RRC_lnactive) and, at step 501, is initially camping on the first cell (e.g., Cell#1), the first cell being controlled by a first gNB 530. The NCR 520 may, at step 503, perform a cell reselection procedure, for example, in response to a cell reselection criterion (see Figure 2, step 203) being fulfilled. Following the cell reselection procedure, at step 505, the NCR 520 may reselect and camp on the second cell, the second cell controlled by a second gNB 540. In this example, the second gNB 540 controlling the second cell may remain unaware of the presence of the NCR 520 camping on the second cell. For instance, when in idle or inactive mode, the NCR 520 is camping on (monitoring) the serving cell thus not actively communicating with the controlling base station. The NCR 520 may indicate presence to the gNB 540 of the new (i.e., second) cell. For example, to support the performing of a forwarding function (NCR-Fwd) from the gNB to the target UE, the NCR 520 may indicate presence to the gNB 540 of the new (i.e., second) cell. As set out at step 507, following reselection to the second cell, the NCR may transmit a message reporting its presence on the second cell to the gNB 540. In some examples, as shown at step 507, this can be performed within an RRC message (e.g., RRC Setup Procedure). However, it will be appreciated that this example is non-limiting, and it may be otherwise signalled. On receipt of the reporting message at the second gNB 540, at step 509, the second gNB 540 may then transmit (i.e., is arranged to transmit on or following receipt of the message), a notification (e.g., inter-gNB notification) to the first gNB 530 indicating migration of the NCR 520 from the first cell to the second cell or, more generally, presence of the NCR 520 on the second cell. This notification may be referred to as an NCR migration notification, and may be in a separate inter-gNB message, or a flag or information element of an existing message. In some non-limiting examples, this existing message may comprise one of: Handover Success, Handover Report, Failure Indication. Thus, the first gNB 530 controlling the first cell may be made aware of the migration away of the NCR 520. In some examples, the second cell may be within the same tracking area, or RAN notification area (RNA), such that the NCR 520 may move freely within these areas without initiating a location update. Such location updates may comprise a tracking area update and / or an RNA update, respectively. In a further example, when in either RRCJdle or RRC_lnactive modes, the NCR 520 may report presence through utilising Tracking Area configurations. In a particular example, and referring back to Figure 4 and 5, after performing cell reselection procedure, the selected second cell may be determined by the NCR 520 to be in a different tracking area to the area of the first cell or, more generally, the NCR 520 may determine that it is in a different tracking area. In various examples, these tracking areas may be NCR-specific, that is, configured differently to tracking areas utilised by UE for reporting presence, as described below. Figure 6 illustrates an example of a configuration of tracking areas and NCR-specific tracking areas for a repeater node (e.g. NCR). It will be appreciated that one or more of the operations shown in Fig. 6 may be omitted, replaced and / or re-ordered, thereby providing additional examples of the present disclosure. It will further be appreciated how, in various examples of the present disclosure, the method of Fig. 6 may be combined with another method disclosed herein, such as that of Fig. 2, Fig. 3, Fig. 4 or Fig. 5. Figure 6 shows Cells #1-#4, which are arranged, or covered, by tracking areas TA1-TA4, and NCR tracking areas, NCR TA1-4. In this example, tracking areas TA 1 and TA2 correspond to mobile tracking areas of the NG-RAN, for example as set out in 3GPP TS 23.501 [2], Such areas correspond to regions through which the idle mobile (i.e. a UE in an idle state) may move without needing to inform the network. In this example, each cell (Cell #1-#4) is associated with one of tracking areas TA1 or TA2, as shown. Specifically, Cells #1 and #3 lie within TA1 and Cells #2 and #4 lie within TA2. In the example shown in Figure 6, each cell may also be associated with an NCR-Specific tracking area, NCR TA1-4. These may be termed NCR Tracking Areas (NCR TA, or nTA), and represent regions through which the NCR (in idle, or inactive state) may move without needing to inform the network. In the example shown, it can be seen that each of cells #1-#4 are located, respectively, in NCR TA1-4. However, in other examples it is apparent that one or more cells may lie within each NCR TA (nTA). In comparison to tracking areas (e.g., TA), the NCR TAs define different sizes (for example, in area or cells) of the NG-RAN, within which an NCR may freely move. For example, following cell reselection, and on selecting to camp on a second cell, the NCR may determine that the new (second) cell to be in a different location area to the first cell prior to reselection. The location area may correspond to either a tracking area, or a RAN notification area (or simply, notification area). In some examples, the NCR message indicating presence in a new location area may also include indication of presence in the current (second) cell. In an example, when the NCR is camping on the second cell, and the second cell is determined to be in new tracking area (or new tracking area lies outside a tracking area list), the NCR may transmit a message to a network entity (e.g., an AMF) indicating presence in the new tracking area. In some examples the indication of presence may be performed within a registration update message. In other examples, the indication of presence in a new tracking area may be a separate message, e.g. NCR presence update. In further examples, the NCR may report presence through an existing message or report, e.g., RRC signalling. Whilst the example of Figure 6 illustrates NCR tracking areas, it may similarly understood that one tracking area can be further divided into a RAN notification areas, RNAs, as indicated in 3GPP TS 38.300 [3] (e.g., referring to clause 9.2.2.3). In some examples, the NCR-specific tracking areas, nTAs, may be further divided into NCR-specific RNA areas. In an example, when in RRC_lnactive, the NCR may determine the location area of the second cell to be a new RAN notification area. In this example, the NCR may report presence to a controlling network entity (e.g., a gNB) of the second cell through the use of RAN Notification Area Update (RNAU). In this example, the NCR may report presence through transmittal of a message indicating presence in the new RNA and / or cell. In some examples, the indication of presence in a new RNA can be a separate message, e.g., RNA update. In other examples, the NCR can report presence through an existing message or report. Figure 7 is an example of configuring measurement relaxation for a repeater node (e.g., an NCR). It will be appreciated that one or more of the operations shown in Fig. 7 may be omitted, replaced and / or re-ordered, thereby providing additional examples of the present disclosure. It will further be appreciated how, in various examples of the present disclosure, the method of Fig. 7 may be combined with another method disclosed herein, such as that of one of Figs. 2 to 6. As indicated at step 701, in this example, the NCR may camp on a first cell and may be in an idle or inactive state (e.g., RRCJdle or RRCJnactive). At step 703, when in an idle (or inactive) state, the NCR may perform measurement (e.g., as relating to cell selection) without applying measurement relaxation. For example, the NCR may ignore broadcast measurement parameters from the gNB (i.e., as may be intended for a UE). Figure 8 is a further example of configuring measurement relaxation for a repeater node (e.g. NCR). It will be appreciated that one or more of the operations shown in Fig. 8 may be omitted, replaced and / or re-ordered, thereby providing additional examples of the present disclosure. It will further be appreciated how, in various examples of the present disclosure, the method of Fig. 8 may be combined with another method disclosed herein, such as that of one of Figs. 2 to 6. At step 801, in this example, the NCR may camp on a first cell, and may be in either an idle or inactive state(e.g., RRCJdle or RRC_lnactive). At step 803, the NCR may determine if NCR-Fwd is in an ON state, and may perform measurement (e.g., as relating to cell selection) based on whether the NCR-Fwd is in an OFF or ON state. In examples, if the NCR-Fwd is determined to be in an ON state at step 803, the NCR may, at step 805, perform said measurements by applying measurement relaxation. For example, the NCR may apply measurement relaxation parameters as received from a broadcast by the gNB. In this example, the NCR may apply measurement relaxation regardless of the signal strength with the gNB. In another example, if at step 803 NCR-Fwd is determined to be OFF, the NCR may determine, at step 807, to perform measurement without configuration of measurement parameters. In this example, the NCR may determine not to apply (or to ignore) broadcast measurement parameters by a gNB. Therefore, by configuring measurement relaxation based on a state of NCR-Fwd, it can be provided that unnecessary cell reselection (i.e. without relaxation), is reduced when NCR-Fwd is performing a forwarding operation. Figure 9 is a block diagram of an exemplary apparatus, or network entity, that may be used in examples of the present disclosure. The skilled person will appreciate said entity may be implemented, for example, as a network element on a dedicated hardware, as a software instance running on a dedicated hardware, and / or as a virtualised function instantiated on an appropriate platform, e.g. on a cloud infrastructure. The entity 1000 comprises a processor (or controller) 1001, a transmitter 1003 and a receiver 1005. The receiver 1005 is configured for receiving one or more messages from one or more other network entities, for example as described above. The transmitter 1003 is configured for transmitting one or more messages to one or more other network entities, for example as described above. The processor 1001 is configured for performing one or more operations, for example according to the operations as described above. The techniques described herein may be implemented using any suitably configured apparatus and / or system. Such an apparatus and / or system may be configured to perform a method according to any aspect, embodiment, example or claim disclosed herein. Such an apparatus may comprise one or more elements, for example one or more of receivers, transmitters, transceivers, processors, controllers, modules, units, and the like, each element configured to perform one or more corresponding processes, operations and / or method steps for implementing the techniques described herein. For example, an operation / function of X may be performed by a module configured to perform X (or an X-module). The one or more elements may be implemented in the form of hardware, software, or any combination of hardware and software. It will be appreciated that examples of the present disclosure may be implemented in the form of hardware, software or any combination of hardware and software. Any such software may be stored in the form of volatile or non-volatile storage, for example a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a CD, DVD, magnetic disk or magnetic tape or the like. It will be appreciated that the storage devices and storage media are embodiments of machine-readable storage that are suitable for storing a program or programs comprising instructions that, when executed, implement certain examples of the present disclosure. Accordingly, certain examples provide a program comprising code for implementing a method, apparatus or system according to any example, embodiment, aspect and / or claim disclosed herein, and / or a machine-readable storage storing such a program. Still further, such programs may be conveyed electronically via any medium, for example a communication signal carried over a wired or wireless connection. While the invention has been shown and described with reference to certain examples, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention, as defined by the appended claims. Abbreviations / Definitions 3GPP 3rd Generation Partnership Project 5G 5th Generation 5GC 5G Core 5QI 5G QoS Identifier 5GS 5G System 5GSM 5G System Session Management 5GMM 5G System Mobility Management AF Application Function Al Artificial Intelligence AM Acknowledged Mode AMF Access and Mobility Management Function AS Application Server ASP Application Service Provider AUSF Authentication Server Function CDN Content Delivery Network DCAF Data Collection Application Function DNAI Data Network Access Identifier DNN Data Network Name DNS Domain Name Server DRB Data Radio Bearer eNB Evolved Node B EPC Evolved Packet Core FEC Forward Error Correction Fwd Forward FQDN Fully Qualified Domain Name GBR Guaranteed Bit Rate gNB Next generation Node B GPSI Generic Public Subscription Identifier HSS Home Subscriber Service IAB Integrated Access and Backhaul ID Identity / ldentifier lloT Industrial Internet of Things IMEI International Mobile Equipment Identities IP Internet Protocol l-SMF Intermediate SMF LADN Local Area Data Network LL SSM Lower Layer SSM LTE Long Term Evolution MBMS Multimedia Broadcast / Multicast Service MBS Multicast / Broadcast Service MBSF Multicast / Broadcast Service Function MBSTF Multicast / Broadcast Service Transport Function MB-SMF Multicast / Broadcast Session Management Function MB-UPF Multicast / Broadcast User Plane Function ML Machine Learning MME Mobility Management Entity MN Master Node MNO Mobile Network Operator Msg Message MT Mobile Termination NAS Non-Access Stratum NCR Network-Controlled Repeater NEF Network Exposure Function NRF Network Repository Function NG-RAN Next Generation Radio Access Network NG-eNB Next Generation eNB NSA Non-Standalone NSSF Network Slice Selection Function NTN Non-Terrestrial Networks NUL Normal Uplink NW Network NWDAF Network Data Analytics Function OS Operating System OSAPP OS Application PCF Policy Control Function PCO Protocol Configuration Options PDR Packet Detection Rule PDU Protocol Data Unit PMN Public Land Mobile Network PTM Point To Multipoint PTP Point to Point QFI QoS Flow Identifier (ID) QoS Quality of Service RACH Random Access Channel RAN Radio Access Network RF Radio Frequency RNA RAN Notification Area RRC Radio Resource Control RRM Radio Resource Management RSD Route Selection Descriptor RSRP Reference Signal Received Power SA Standalone SDAP Service Data Adaptation Protocol SDU Service Data Unit SGW Serving Gateway SI System Information SIM Subscriber Identity Module SLA Service Level Agreement SM Session Management SMF Session Management Function SN Secondary Node SNPN Stand Alone Non-Public Network S-NSSAI Single Network Slice Selection Assistance Information SSB Synchronization Signal Block SSM Source Specific IP Multicast address SSC Session and Service Continuity SRB Signaling Radio Bearer SUPI Subscription Permanent Identifier TA Tracking Area TAG Timing Advance Group TAI Tracking Area Identity TE Terminal Equipment TM Transparent Mode TMGI Temporary Mobile Group Identity 5 TS Technical Specification UDM Unified Data Manager UDR Unified Data Repository UE User Equipment UL Uplink 10 UM Unacknowledged Mode UP User Plane UPF User Plane Function URLLC Ultra-Reliable and Low-Latency Communication URSP UE Route Selection Policy 15 03 02 25

Claims

1. A method, of a repeater node controlled by a network and configured to perform a forwarding function in the network, the method comprising:5 when camping on a first cell of the network, detecting a trigger for performing cellreselection;in response to a second cell being selected during the cell reselection, camping on the second cell, andmodifying the forwarding function.

102. The method of claim 1, further comprising:when performing the cell reselection, identifying, based on at least one cell selection criterion, the second cell to not be a suitable cell based on at least one cell selection criterion.15 3. The method of any preceding claim:wherein the detected trigger is a trigger for performing a network re-selection, andwherein the second cell is located in a second network different to the network of the first cell.20 4. The method of claim 1 or 2, wherein the detected trigger is a trigger for performing anetwork re-selection, and the method further comprises:receiving a signal rejecting a selected network during the network re-selection.

5. The method of claim 1 or 2, wherein the detected trigger is a trigger for performing a25 network re-selection, and the method further comprises:receiving a signal accepting a selected network during the network re-selection.

6. The method of any of claims 1 to 5, wherein modifying the forwarding function comprises changing the forwarding function from an on state to an off state.

307. The method of claim 6, wherein the off state comprises:preventing a state in which the repeater node forwards data; orforwarding configuration of the repeater node is discarded; and / ora default forwarding configuration is applied.

8. The method of claim 6 or claim 7, wherein the on state comprises one of:performing the forwarding function for all signals;performing the forwarding function selected signals;5 performing the forwarding function for specific transmissions received from a networkentity controlling the first cell; andperforming the forwarding function on specific transmissions by the repeater node.

9. The method of any preceding claim, wherein the first cell is selected as the second cell. 1010. An apparatus configured to perform the method of any of claims 1 to 9.

11. A computer program comprising instructions which, when the program is executed by a computer or processor, cause the computer or processor to carry out a method according to any 15 one of claims 1 to 9.

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