Access control for network energy saving

Abstract

Examples of the disclosure relate to access control for network energy saving. In examples of the disclosure an apparatus receives, from a network node, at least one network energy saving mode parameter of the network node and at least one evaluation criterion for the apparatus to determine whether to initiate an access procedure with the network node. The apparatus determines, based on the at least one network energy saving mode parameter and the at least one evaluation criterion, whether to initiate the access procedure with the network node.

Description

[0001]TITLEAccess Control for Network Energy SavingTECHNOLOGICAL FIELDExamples of the disclosure relate to access control. Some relate to access control fornetwork energy saving. BACKGROUND Network energy saving (NES) can be used by communications networks to improve environmental sustainability, to reduce environmental impact, and for operational cost savings. BRIEF SUMMARY According to various, but not necessarily all, examples of the disclosure there is providedan apparatus comprising: at least one processor;and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to perform: receiving, from a network node, at least one network energy saving mode parameter of the network node; receiving, from the network node, at least one evaluation criterion for the apparatus to determine whether to initiate an access procedure with the network node; and determining, based on the at least one network energy saving mode parameter and the at least one evaluation criterion, whether to initiate the access procedure with the network node.The at least one network energy saving mode parameter may comprise at least one of:a network energy saving barring factor; a network energy saving barring time; an indication of an energy saving mode of the network node.The apparatus may be caused to perform:determining that the at least one evaluation criterion is satisfied; and based on determining that the at least one evaluation criterion is satisfied, initiating the access procedure with the network node.The at least one network energy saving mode parameter may comprise at least thenetwork energy saving barring time; and the apparatus is caused to perform: determining that the at least one evaluation criterion is not satisfied; based on determining that the at least one evaluation criterion is not satisfied, determining a time period at least based on the network energy saving barring time; waiting until the determined time period expires before a next attempt to access a cell provided by the network node.The at least one network energy saving mode parameter may comprise differentparameters for different energy saving modes of the network node.The different network energy saving modes may comprise at least a first mode and asecond mode, wherein a number of active resources at the network node is higher in the first mode than in the second mode.The at least one network energy saving mode parameter may be associated with aspecific type of the apparatus.The at least one network energy saving mode parameter may comprise an indication ofthe energy saving mode of the network node and the apparatus is caused to performdetermining at least one of a network energy saving barring factor or a network energysaving barring time, based at least in part on the indication of the energy saving mode ofthe network node.The at least one evaluation criterion may comprise a mathematical operation based onthe at least one network energy saving mode parameter.The apparatus may be caused to perform:receiving an update for the at least one network energy saving mode parameter of the network node; updating or replacing the at least one network energy saving mode parameter based on the update.The at least one network energy saving mode parameter may comprise informationspecific to at least one of: an access category; oran access identity.The at least one network energy saving mode parameter may be received as additionalinformation to unified access control parameters.The at least one network energy saving mode parameter of the network node may bereceived via at least one of: -a broadcast message;- unified access control information;- a master information block; or- a system information block.The at least one evaluation criterion for the apparatus to determine whether to initiatethe access procedure with the network node may be received via at least one of:- a broadcast message;- unified access control information;- a master information block; or- a system information block.The apparatus may comprise or may be comprised in one of:- a user equipment;- an energy harvesting device;- a reduced capability device;- an internet of things device; or- an ambient internet of things device.According to various, but not necessarily all, examples of the disclosure there is provided a method comprising: receiving, from a network node, at least one network energy saving mode parameter of the network node; receiving, from the network node, at least one evaluation criterion for the apparatus to determine whether to initiate an access procedure with the network node; and determining, based on the at least one network energy saving mode parameter and the at least one evaluation criterion, whether to initiate the access procedure with the network node. According to various, but not necessarily all, examples of the disclosure there is provided a computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform at least: receiving, from a network node, at least one network energy saving mode parameter of the network node; receiving, from the network node, at least one evaluation criterion for the apparatus to determine whether to initiate an access procedure with the network node; and determining, based on the at least one network energy saving mode parameter and the at least one evaluation criterion, whether to initiate the access procedure with the network node. According to various, but not necessarily all, examples of the disclosure there is provided a network node comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network node at least to perform: determining at least one network energy saving mode parameter of the network node; determining at least one evaluation criterion for an apparatus to determinewhether to initiate an access procedure with the network node; andtransmitting to the apparatus the at least one network energy saving mode parameter of the network node and the at least one evaluation criterion for the apparatus.The at least one network energy saving mode parameter may comprise at least one of:a network energy saving factor; a network energy saving barring time; or an indication of an energy saving mode of the network node.The at least one network energy saving mode parameter may comprise differentparameters for different energy saving modes of the network node.The different network energy saving modes may comprise at least a first mode and asecond mode, wherein a number of active resources at the network node is higher in the first mode than in the second mode.The at least one network energy saving mode parameter may be associated with aspecific type of the apparatus.The at least one evaluation criterion may comprise a mathematical operation based onthe at least one network energy saving mode parameter.The network node may be caused to perform:determining an update for the at least one network energy saving mode parameter of the network node wherein the update relates to changes in at least one of a current network load or an upcoming network load; transmitting to the apparatus the update to the at least one network energy saving mode parameter.The at least one network energy saving mode parameter may comprise informationspecific to at least one of: an access category; an access identity.The at least one network energy saving mode parameter may be transmitted asadditional information to unified access control parameters.The at least one network energy saving mode parameter of the network node may betransmitted via at least one of: -a broadcast message;- unified access control information;- a master information block; or- a system information block.The at least one evaluation criterion for the apparatus to determine whether to initiatethe access procedure with the network node may be transmitted via at least one of:- a broadcast message;- unified access control information;- a master information block; or- a system information block.According to various, but not necessarily all, examples of the disclosure there is provided a method comprising: determining at least one network energy saving mode parameter of the network node; determining at least one evaluation criterion for an apparatus to determinewhether to initiate an access procedure with the network node; andtransmitting to the apparatus the at least one network energy saving mode parameter of the network node and the at least one evaluation criterion for the apparatus. According to various, but not necessarily all, examples of the disclosure there is provided a computer program comprising instructions which, when executed by an network node, cause the network node to perform at least: determining at least one network energy saving mode parameter of the network node; determining at least one evaluation criterion for an apparatus to determinewhether to initiate an access procedure with the network node; andtransmitting to the apparatus the at least one network energy saving mode parameter of the network node and the at least one evaluation criterion for the apparatus. While the above examples of the disclosure and optional features are described separately, it is to be understood that their provision in all possible combinations andpermutations is contained within the disclosure. It is to be understood that variousexamples of the disclosure can comprise any or all of the features described in respectof other examples of the disclosure, and vice versa. Also, it is to be appreciated that anyone or more or all of the features, in any combination, may be implemented by / comprised in / performable by an apparatus, a method, and / or computer program instructions as desired, and as appropriate. BRIEF DESCRIPTIONSome examples will now be described with reference to the accompanying drawings inwhich: FIG.1 shows an example network; FIG.2 shows an example method; FIG.3 shows an example method; FIG.4 shows an example signaling chart; FIG.5 shows an example network; FIG.6 shows an example of traffic change; and FIG.7 shows an example apparatus.The figures are not necessarily to scale. Certain features and views of the figures can beshown schematically or exaggerated in scale in the interest of clarity and conciseness. For example, the dimensions of some elements in the figures can be exaggeratedrelative to other elements to aid explication. Similar reference numerals are used in thefigures to designate similar features. For clarity, all reference numerals are notnecessarily displayed in all figures. DEFINITIONSAC Access CategoryAI Access IdentityAIoT Ambient Internet of ThingsgNB NR base stationIoT Internet of ThingsMIB Master Information BlockNES Network Energy SavingRedCap Reduced CapabilityRRC Radio Resource ControlSIB System Information BlockUAC Unified Access ControlUE User EquipmentUL UplinkDETAILED DESCRIPTION Fig.1 illustrates an example of a communications network 100 such as a 5G network ora 6G network or any other suitable type of network. The network 100 comprises aplurality of different types of nodes 110, 120, 130. The different types of nodes 110, 120,130 can comprise terminal nodes 110, and network nodes 120, 130. The network nodescan comprise access nodes 120 and core network nodes 130 and / or any other suitable type of apparatus. The access nodes 120 can be configured to communicate with the terminal nodes 110. The core network nodes 130 communicate with the access nodes 120. In some examples the core network nodes 130 communicate with the terminal nodes 110. The core network nodes 130 can, in some examples, communicate with each other. The one or more access nodes 120 can, in some examples, communicate with each other. The network 100 can be a cellular network comprising a plurality of cells 122. Each of the cells is served by an access node 120. In this example, the interface between theterminal node 110 and an access node 120 providing a cell 122 is a wireless interface124. The access nodes 120 can comprise one or more cellular radio transceivers. The terminal nodes 110 can comprise one or more cellular radio transceivers. The terminal nodes 110 can comprise user equipments (UE), energy harvesting devices,reduced capability (RedCap) devices, internet of things (IoT) devices, ambient internetof things (AIoT) devices, or any other suitable type of devices.The access nodes 120 can be base stations. The access nodes 120 can be any suitable type of base station. The access node 120 can be a network entity responsible for radiotransmission and reception in one or more cells to or from terminal nodes 110. Theaccess node 120 can be a network element in a Radio Access Network (RAN), or any other suitable type of network.The core network nodes 130 can be part of a core network. The core network nodes 130can be configured to manage functions relating to connectivity for the terminal nodes110. For example, the core network nodes 130 can be configured to manage functionssuch as connectivity, mobility, authentication, authorization and / or other suitable functions.In the example of Fig. 1 the core network node 130 is shown as a single entity. In someexamples the core network node 130 could be distributed across multiple entities. For example, the core network node 130 could be cloud based or distributed in any other suitable manner. The network 100 can be any suitable type of network, for example it can be a New Radio (NR) network that uses gNB as access nodes. New Radio is the 3GPP name for 5Gtechnology. In such cases the serving nodes 120 can comprise gNBs configured toprovide user plane and control plane protocol terminations towards the terminal nodes 110 and / or to perform any other suitable functions. The gNBs are interconnected with each other by means of an X2 / Xn interface 126. The gNBs are also connected by meansof the N2 interface 128 to the core network nodes 130. Other types of networks andinterfaces could be used in other examples. Other types of networks could comprisenext-generation mobile and communication network, for example, a 6G network. Unified Access Control (UAC) is a mechanism to determine whether a UE is allowed toaccess the network or specific services. UAC parameters can be broadcasted for all UEson the cell and UEs may have up-to-date UAC information before the UE starts theaccess attempt. Network can restrict access of the UEs using UAC without a need forrejection. When the UE may need to access a 5G system, the UE first performs accesscontrol checks to determine if the access is allowed. Access attempt may relate to, forexample, multimedia priority service (MPS), mission-critical service (MCS), or a disastercondition, etc. In UAC check, a UE maps its access attempt to an access category (AC)and one or more access identities (AIs) based on mapping rules, which may be pre- defined in standard specifications.The UE may have received barring information, e.g. via SIB1 message. For each AC,barring information may comprise a barring factor, barring time, and barring indicator foreach AIs. A barring indication for each AI informs whether an access attempt is allowedfor this AI for this AC. The barring factor indicates the probability that a given access request can be allowed. The barring time defines the minimum time interval, e.g. UAC-BarringTime, before a new access attempt can be performed after it was barred. Then,the UE may perform an access barring check as defined in TS 24.501 and TS 38.331.Network energy saving (NES) is important for networks such as the network 100 of Fig.1. NES helps to improve environmental sustainability, reduce environmental impact, andprovide operational cost savings. A significant proportion of the energy consumptioncomes from the radio access network and in particular from the active antenna unit (AAU). The power consumption of a radio access can be split into two parts: the dynamic part which is only consumed when data transmission / reception is ongoing, and the static part which is consumed all the time to maintain the necessary operation of the radio access devices, even when the data transmission / reception is not on-going.A network node or access node 120 can have one or more NES modes. The differentNES modes or energy saving modes can have different levels of energy usage. Forexample, a first NES mode could have a first amount of the antenna resources activewhile a second NES mode could have a second amount of the antenna resources activewhere the first and second amounts are different. An NES mode or energy saving modemay relate to adaptation of at least one of: antenna resource usage, bandwidth of activebandwidth part (BWP), transmission power, time (slots occupied for DL transmissions).For example, antenna resource usage may be adapted via adaptation of spatialelements / antennas. This adaptation aims to dynamically adapt the spatial elementsusing a scaling factor (e.g. ^ ^) for the fraction of active antenna elements at the networknode.For example, transmission power of signals or channels may be adapted. Thisadaptation aims at adapting the transmission power or power spectral density (PSD) ofdownlink signals using a scaling factor (e.g. ^ ^) for the ratio of PSD per transmission(Tx) between the DL transmission and reference configuration.For example, bandwidth of active BWP may be adapted. This adaptation aims atadapting the bandwidth of active BWP using a scaling factor (e.g. ^ ^) for the ratiobetween the RF bandwidth and the maximum system BW.For example, adaptation in time domain aims at adapting the slots occupied with DLtransmissions using a scaling factor (e.g. ^ ^) for the active slots occupied with data.Let us consider apparatuses or devices such as an energy harvesting device, a RedCapdevice, an IoT device, an AIoT device, which may be referred to as a low-priority deviceor low-priority user equipment, UE. When a UE, e.g. a low-priority UE, wakes up anetwork node, which is in NES mode, it is inefficient from a NES point of view. Examples of the disclosure provide methods and apparatuses configured to perform themethods to prevent UEs, e.g. low-priority UEs, from accessing the cells that are adopting NES techniques. For example, there is provided an access control process that canaccount for different NES modes or energy saving modes of a network 100.Fig.2 shows an example method that may be implemented in examples of the disclosure.The method of Fig.2 may be implemented by an apparatus comprising a terminal node110, e.g. UE, or an apparatus within a terminal node 110. For example, the apparatusconfigured to perform at least the method may be one of: a UE, a low-priority UE, anenergy harvesting device, a RedCap device, an IoT device, an AIoT device. The methodof Fig.3 is a method that could be implemented by a network node 120, e.g. gNB. The respective methods can be performed as part of an access procedure for a network 100 that can implement NES. The method of Fig. 2 comprises, at block 200, receiving from a network node 120, atleast one NES mode parameter of the network node 120. The NES mode parameter canbe an indication of an NES mode of the network node 120. The NES mode parameterscan comprise NES barring factor, an NES barring time, and / or any other suitableparameters. The at least one NES mode parameter can comprise different parameters for differentenergy saving modes of the network node 120. The different energy saving modes of thenetwork node 120 can comprise different amounts of resources of the network node 102being active or any other different types of arrangements of the network node 120. Forexample, the different NES modes or energy saving modes can comprise at least a firstmode (e.g. mode 1) and a second mode (mode 2), wherein the number of activeresources at the network node 120 is higher in the first mode than in the second mode.For example, in mode 1, 75 % of the resources of the network node are active; in mode2, 50 % of the resources of the network node are active; in mode 3, 25 % of the resourcesof the network node are active.The NES mode parameters can be associated with a specific type of apparatus. Thedifferent types of apparatus could be, or could be comprised within, a UE, an energy harvesting device, a RedCap device, an IoT device, an AIoT device or any other suitabletype of device. The different NES mode parameters associated with the different typesof apparatus can account for different levels of priority of the types of apparatus. Forexample, apparatuses or devices such as an energy harvesting device, a RedCap device, an IoT device, an AIoT device may be referred to as a low-priority device or low- priority UE. In some examples the at least one NES mode parameter can comprise informationspecific to an access category (AC) and / or an access identity (AI). This can enabledifferent NES mode parameters to be associated with different access categories and / ordifferent access identities.The at least one NES mode parameter can be received in any suitable format. In someexamples the at least one NES mode parameter can be received as additional information to unified access control (UAC) parameters.The at least one NES mode parameter can be received in any suitable signalling. Insome examples the NES mode parameter can be received in a broadcast message, UAC information, a master information block (MIB) or a system information block (SIB). At block 202 the method comprises receiving, from the network node 120, at least one evaluation criterion for the apparatus to determine whether to initiate an accessprocedure with the network node 120. The evaluation criterion can comprise amathematical operation. The mathematical operation can be based on the at least oneNES mode parameter. The mathematical operation can be performed by the apparatusat block 204. Examples of mathematical operations are given below.The access procedure that the evaluation criterion relates to can be any type of accessprocedure. The access procedure can be a random access procedure, a Radio ResourceControl (RRC) connection resume procedure, or any other suitable type of access procedure.The at least one evaluation criterion can be received in any suitable signalling. In someexamples the NES mode parameter can be received in a broadcast message, UACinformation, a master information block (MIB) or a system information block (SIB).The receiving 200 of the NES mode parameter and the receiving 202 of the evaluationcriterion are shown as separate blocks in Fig.2. In other examples they could be receivedtogether, e.g. in the same signalling or the same message. If the NES mode parameterand the evaluation criterion are received separately then they can be received in anyorder. That is, the NES mode parameter can be received before the evaluation criterionor the evaluation criterion can be received before the NES mode parameter. At block 204 the method comprises determining whether to initiate the access procedurewith the network node. The determination is based on the at least one NES modeparameter and the at least one evaluation criterion. The determination can compriseperforming one or more mathematical operations defined by the evaluation criterion where the at least one NES mode parameter is used in the one or more mathematical operations. If, at block 204, it is determined that the at least one evaluation criterion is satisfied thenthe apparatus will initiate the access procedure with the network node 120. An evaluationcriterion could be satisfied if the output of the mathematical operations satisfies the requirements defined by the evaluation criterion. If, at block 204, it is determined that the at least one evaluation criterion is not satisfiedthen the apparatus determines a time period. The time period can be based on an NESbarring time. Examples of calculation of the timer period are given below. The NESbarring time can be one of the NES mode parameters that is received at block 200. Theapparatus will wait until the determined time period expires before the apparatus makes a next attempt to access a cell provided by the network node 120. In some examples of the disclosure the method can also comprise receiving an updatefor the at least one NES mode parameter of the network node 120. The NES modeparameter could be updated by the network node 120 due to changes in the networkload. The changes in the network load could be a current network load or an upcomingnetwork load. The updates to the NES mode parameter could be received using anysuitable signalling. The apparatus could then update or replace the at least one NESmode parameter based on the received update. The apparatus can then use the updateor replaced NES mode parameter in an evaluation criterion.In some examples the NES mode parameter that is received from the network node cancomprise an indication of the NES mode. For example, the parameter could indicate ifthe network node is using mode 1, in which e.g. 75 % of the resources of the networknode are active; mode 2, in which e.g. 50 % of the resources of the network node areactive; or mode 3, in which e.g. 25 % of the resources of the network node are active.Other modes with different percentages can be used in other examples. In such casesthe apparatus can be caused to perform determining at least one of an NES barringfactor or an NES barring time, based at least in part on the indicated network energysaving mode. The determination of the NES barring factor or the NES barring time by the apparatus can also be based on other criteria. The other criteria can comprise criteria specific tothe apparatus. This can provide improved flexibility for the apparatus. For example, theNES barring factor or the NES barring time, can be determined based, at least in part, on a buffer status of the apparatus. In such cases the apparatus can determine if the buffer of the apparatus is full, or above a threshold level. If the buffer is full or above athreshold level then apparatus could use an NES barring factor and / or NES barring timesuch that the apparatus is allowed to transmit to avoid any data loss. If the buffer is notfull or is below a threshold level then apparatus could use an NES barring factor and / orNES barring time such that the apparatus restricts the access until more resources areavailable at the network node. The apparatus may also take into account its quality ofservice (QoS) requirements. For example, if QoS requirements are not too strict and thebuffer is empty or not full or is below a threshold level, the apparatus could use an NESbarring factor and / or NES barring time such that the apparatus restricts the access untilmore or all resources are available at the network node.Fig.3 shows an example method that may be implemented in examples of the disclosure.The method of Fig.3 may be implemented by an apparatus comprising a network node120, e.g. gNB, or an apparatus within a network node 110. For example, the apparatusconfigured to perform at least the method may be a network node, e.g. gNB. The methodof Fig.3 is a counterpart method to the method of Fig. 2.At block 300 the method comprises determining at least one NES mode parameter ofthe network node 120.At block 302 the method comprises determining at least one evaluation criterion for anapparatus (UE) to determine whether to initiate an access procedure with the networknode 120.At block 304 the method comprises transmitting to the apparatus the at least one NES mode parameter of the network node 120 and the at least one evaluation criterion for theapparatus. The NES parameter and the evaluation criterion can be transmitted to theapparatus to enable the apparatus to perform the method shown in Fig.2. The NES parameter and the evaluation criterion can be transmitted using any suitablesignalling such as a broadcast message, UAC information, a master information block(MIB) or a system information block (SIB).The NES parameter and the evaluation criterion can be transmitted separately ortogether, e.g. in the same signalling or the same message. If the NES mode parameterand the evaluation criterion are transmitted separately then they can be transmitted inany order. That is, the NES mode parameter can be transmitted before the evaluationcriterion or the evaluation criterion can be transmitted before the NES mode parameter.Fig.4 shows an example signaling chart that could be used in examples of the disclosure.In this example the signaling is between a UE and a gNB. Other types of terminal node110 and network node 120 could be used in other examples. For example, the UE maybe a low-priority UE as described earlier.The example method shown in Fig. 4 could be used to adapt a UAC procedure. Theexample method can be used to restrict network access through the use of one or moreNES mode parameters and corresponding evaluation criterion.At block 400 the method comprises transmitting one or more NES mode parameters andone or more evaluation criterion from the gNB to the UE. The NES mode parametersand one or more evaluation criterion can be transmitted in a broadcast message, UAC information, a master information block (MIB) or a system information block (SIB), or in any other suitable signalling. In examples where the NES mode parameters and one or more evaluation criterion are transmitted with UAC information the signaling at block 400 can also comprise a barringfactor, barring time and barring indicator for each Access Identity (AI). The NES modeparameters and evaluation criterion can be provided as additional information to the barring factor, barring time and barring indicator. The NES mode parameters can comprise an NES barring factor, an NES barring time, and / or any other suitable parameters or combinations of parameters.The NES mode parameters can be different for different NES modes of the gNB. TheNES modes parameters can be set so as to implement different limits on network trafficfor different NES modes. For example, a first NES mode could comprise the gNB using a sleep mode having a first duration and a second NES mode could comprise the gNB using a sleep mode having a second duration where the second duration is longer thanthe first duration. In this example the NES parameter, e.g. NES barring factor, could beset lower for the second NES mode so as to reduce access requests for the gNB. Forexample, configuring a value of ‘0’ for NES barring factor, all access control checks will lead to barred access attempts. In some examples a first NES mode could comprise a first amount of resources being active and a second NES mode could comprise a second amount of resources being active where the second amount is less than the first amount. In such examples the NESparameter, e.g. NES barring factor, could be set lower for the second NES mode so asto reduce access requests for the gNB. For example, configuring a value of ‘0’ for NESbarring factor, all access control checks will lead to barred access attempts. In some examples, NES barring time parameter may be different for different NESmodes. For example, a higher NES barring time may be set so as to increase UE waitingtime and thereby reduce access requests for the gNB.In some examples the NES mode parameters can apply to all UEs. This could be thecase in examples where there are very limited active or available resources at the gNB. In some examples different NES mode parameters can be associated with different typesof UEs. For instance, some UEs can be classed as low priority UEs and could havehigher levels of restrictions compared to other UEs that are not low priority UEs. TheNES mode parameters could apply for the low priority UEs but not for other types of UEs. There could be multiple levels or priority for the UEs and multiple NES mode parametersfor the respective priority levels. The priority level of the UEs can be determined basedon the active resources at the gNB and / or any other suitable factors.At block 402 the gNB can send an updated NES mode parameter. The NES modeparameter can be updated based on changes in a network load. The NES modeparameter can be updated to restrict network traffic to a limit. The change can be for acurrent network load or an upcoming network load. The changes in the NES modeparameter can indicate a change in NES mode being used by the gNB. The network canadjust the NES mode parameters to stop UE access and to keep network traffic below alimit. If the gNB does not determine that an updated NES mode parameter is needed then block 402 can be omitted and the UE can perform the method using the NES mode parameters received at block 400.The updated NES parameter can be transmitted in any suitable signaling. The updatedNES parameter can be transmitted with other information that enables a UE to determine whether or not it is permitted to access a cell. In some examples the updated NES parameter can be transmitted using SIB1.At block 404 the UE determines to perform the connection request. The connectionrequest can enable the UE to transition from an IDLE / INACTIVE mode to aCONNECTED mode. Once the UE has determined to perform the connection request then, at block 406, the UE checks the evaluation criterion to determine whether to initiate an access procedure,e.g. a random access procedure. The UE can map its access attempt to an AC or oneor more AIs . The UE can use the NES mode parameters received at block 400 or 402in the evaluation criterion. In some examples one or more additional parameters can alsobe used in the evaluation criterion. For example, one or more UAC parameters couldalso be used. The evaluation criterion can comprise any suitable mathematical operation. As an example, the evaluation criterion could comprise the UE generating a uniformlydistributed random number rnd between 0 and 1, and evaluating equation 1.rnd ≤ uac_BarringFactor × NESBarringFactor, Eq. (1)If the random number is less than the value of, the product of uac_BarringFactor and NESBarringFactor, then the access attempt is permitted. Otherwise, the access attempt is barred. In this example, configuring a value of ‘0’ for uac_BarringFactor orNESBarringFactor means that all checks of the evaluation criterion will lead to barredaccess attempts. Other equations or mathematical operations can be used in the evaluation criteriondepending on network implementations and NES requirements. In some examples, asshown in equations 2 and 3, the evaluation criterion can be based on an NES barringfactor in combination with a uac_BarringFactor.rnd ≤ (uac_BarringFactor + NESBarringFactor) / 2, Eq. (2)rnd ≤ ^^^(NESBarringFactor − uac_BarringFactor), Eq. (3)In some examples, as shown in equation 4 the evaluation criterion can be based on an NES barring factor alone without any other factors or parameters being used. rnd ≤ NESBarringFactor, Eq. (4)Other evaluation criterion could also be used in examples of the disclosure. In some examples the UE could choose the evaluation criterion to use based on the NESmode or energy saving mode. For instance, in a first NES mode the evaluation criterioncould comprise equation 1 and in a second NEs mode the evaluation criterion couldcomprise equation 2, or any other suitable mathematical operations.If the evaluation criterion is satisfied then the method proceeds to block 408. Theconnection request is not barred and the UE can determine to initiate an accessprocedure with the gNB. The UE can send a connection request to the gNB at block 410.For example, the UE can initiate a random access procedure with the gNB.If the evaluation criterion is not satisfied then the method proceeds to block 412. Theconnection request is barred and the UE determines not to initiate an access procedurewith the gNB. The UE refrains from initiating an access procedure with the gNB. The UEdoes not send a connection request to the gNB at that point. Instead, at block 414 abarring time period is computed. The barring time period can define the duration that theUE treats the cell of the gNB as barred for the corresponding access category. Thebarring time period can be determined by any suitable timer such as T390.The barring time period can be computed using a suitable mathematical operation from the evaluation criterion and any suitable NES mode parameters such as an NES barringtime. The mathematical operation can also use any other suitable parameters such as auac_BarringTime. Equation 5 gives an example of a mathematical operation that can beused to determine the barring time period. T390 = (0.7 + 0.6 ∗ rand) × uac_BarringTime × NESBarringTime, Eq. (5) Other equations or mathematical operations can be used to compute the barring timeperiod depending on network implementations and NES requirements. In someexamples, as shown in equation 6 the evaluation criterion can be based on an NES barring factor in combination with a uac_BarringTime. T390 = [(0.7 + 0.6 ∗ rand) × uac_BarringTime] + NESBarringTime, Eq. (6)In some examples, as shown in equation 7 the computation of the barring time period can be based on an NES barring factor alone without any other factors or parameters being used. T390 = (0.7 + 0.6 ∗ rand) × NESBarringTime, Eq. (7)For example, configuring a value of NES barring time close to ‘0’ means that the UE isallowed to transmit a new connection request without waiting. Thus, a higher NES barringtime may lead to larger waiting time for the UE. For example, a higher NES barring timemay be set so as to increase UE waiting time and thereby reduce access requests for the gNB.At block 416 the UE waits for the expiry of the barring time period. After the barring timeperiod has expired the process can return to block 400 or 402. The UE can make a nextattempt to access a cell provided by the gNB after the barring time period has expired.In some examples, the UE may try to access another network node, if UE is in a coverageof a cell provided by the other network node.If the barring time period is close to 0 then the UE can transmit the connection requestafter the barring time period has expired. If the barring time period is greater than 1 theUE can transmit the connection request after the gNB has deactivated the current NES mode.Figs. 5 and 6 show an example model network and results obtained using the model toindicate the power savings that can be obtained using examples of the disclosure. Theequations used in this model to obtain the results shown in Fig.6 are just one exampleand other equations and models could be used for other types of network node.In these examples the energy consumed by a receiver can be modeled as the energyconsumed by the components that maintain the necessary operation plus the energyconsumed by the decoding stages corresponds to Rx activities. The gNB powerconsumption in active Uplink (UL) state ^^^ can be expressed as shown in equation 8. where ^^ is the fraction of active transceiver units which can be expressed as shown inequation 9. where, ^^^^^^^^^ is the power consumption of the active transceiver units, ^^^^^^^^^^^ isthe power conserved by microsleeps of the active transceiver units, and Δ is theadditional e.g., decoding power consumption.The decoding power consumption can be assumed to increase with the data rate. Thedata rate can be correlated with the coding rate ^. A linear function model can be usedto describe the relationship between the data rate and the power consumed by the decoder can be expressed using equation 10. where ^^ is specific to a decoder and models the decoder efficiency.The expected uplink sum rate ^ = ∑^ ^^^ ^^and NES gain can be defined using equation 11, where ^^^^is active UL state power consumption with maximum load and active UEs. In can be assumed that the UE has (finite) queue buffers to store the network layer data. can denote the queue backlog of ^-th UE during time slot ^, which evolvesaccording to equation 12 ^(^ + 1) = [^ (^) − ^ (^) + ( )]^^ ^ ^ ^^ ^ , ∀^, Eq. (12)where [^]^ = max(^, 0), ^^(^) is the achievable rate, and ^^(^) denotes the data arrivalwith a mean arrival rate of ^[^^(^)] = ^^, ∀^.Fig. 5 schematically shows a network 100 comprising a gNB 500 transmitting data tomultiple UEs 502. In the example of Fig.5 three UEs 502-1, 502-k, 502-K are shown butany number of UEs could be used. Fig. 5 also shows, by way of examples, the queuebacklogs 504-1, 504-K for the respective UEs. In the model it is assumed that an access barring check involves the UE 502 generatinga uniformly distributed random number rnd ∈ [0, 1], and evaluating the networkconfigured values using equation q,rnd ≤ uac_BarringFactor × NESBarringFactor, Eq (1)If the random number is less than the value, then the access attempt is permitted. Otherwise, the access attempt is barred for the current time. A barring access timer suchas timer T390 is not considered for this model.Table 1 gives an indication of the parameter assumptions that were made for thesimulations that were used to obtain the results shown in Fig. 6. This example showsthree different NES modes, a first NES mode-1 where the network has 75% of resources available so that the system limit is reduced by 25%, a second NES mode-2 where the network has 50% of resources available so that the system limit is reduced by 50%, and a third NES mode-3 where the network has 25% of resources available so that the system limit is reduced by 75%, Parameter Assumption Descriptions^^ 1 fraction of active transceiver units^^^^^^^^^ 6.5 for BS category 2 Set 1 [3GPP TR 38.864]^^^^^^^^^^^ 5.5 for BS category 2 Set 1 [3GPP TR 38.864]^^ rand[0.1, 0.4], ∀ ^ decoder efficiencydata arrival Pois(^) Poisson distribution, with parameter ^ > 0.8With UAC 0.9 uac − BarringFactoruac − BarringFactor(0.9)NES Mode-1 ~0.85× NESBarringFactor(0.94)uac − BarringFactor(0.9)NES Mode-2 ~0.8× NESBarringFactor(0.88)uac − BarringFactor(0.9)NES Mode-3 0.75× NESBarringFactor(0.83)Table 1Fig. 6 shows a plot of the change in network traffic over time using the example systemand parameters of Fig. 5 and table 1. Plot 600 shows the traffic change without usingUAC (“Without UAC”), plot 602 shows the traffic change using UAC (“With UAC”), plot604 shows the traffic change using NES mode-1 (“Proposed NES Mode-1”), plot 606shows the traffic change using NES mode-2 (“Proposed NES Mode-2”) and plot 608shows the traffic change using NES mode-3 (“Proposed NES Mode-3”). Table 2 gives an indication of the power consumption and the normalized network energy savings for the respective modes. UAC Scheme PowerNormalized Network Energy Saving [%] consumption Without UAC 83.7525 0With UAC 50.7015 39.4627With UAC + NES Mode-1 39.9487 52.3015With UAC + NES Mode-2 28.7128 65.7171With UAC + NES Mode-3 22.8561 72.7099Table 2In examples of the disclosure when the network 100 identifies that traffic is exceedingthe system limit, the network can use NES mode parameters and evaluation criterion toapply restrictions to UEs so as to keep the traffic under the system limit. The use of theNES mode parameters and evaluation criterion can improve the network energy savingsand can enable the network nodes 120 to have longer sleep durations and / or feweractive resources at the gNB. For example, the NES Mode-3 shown in table 1 providesan NES of up to 72% compared to the baseline scenario.The above results are one possible example case, and these may scale differently fordifferent system configurations, and NES requirements. However, the underlyingrelationship between the parameters of power consumption, achievable rate, andnetwork energy savings, will still hold.Fig.7 illustrates an example apparatus 700. The apparatus 700 could be provided withinan entity such as a data node or a ML node or any other suitable apparatus.Implementation of the apparatus 700 may be as controller circuitry. The apparatus 700may be implemented in hardware alone, have certain aspects in software including firmware alone or can be a combination of hardware and software (including firmware).As illustrated in Fig. 7 the apparatus 700 can be implemented using instructions thatenable hardware functionality, for example, by using executable instructions of acomputer program 706 in a general-purpose or special-purpose processor 702 that maybe stored on a computer readable storage medium (disk, memory etc.) to be executedby such a processor 702.The processor 702 is configured to read from and write to the memory 704. Theprocessor 702 may also comprise an output interface via which data and / or commandsare output by the processor 702 and an input interface via which data and / or commandsare input to the processor 702.The memory 704 stores a computer program 706 comprising computer programinstructions (computer program code) that controls the operation of the apparatus whenloaded into the processor 702. The computer program instructions, of the computerprogram 706, provide the logic and routines that enables the apparatus to perform themethods illustrated in the Figs. The processor 702 by reading the memory 704 is able toload and execute the computer program 706.The apparatus 700 therefore comprises means for:receiving 200, from a network node, at least one network energy saving modeparameter of the network node; receiving 202, from the network node, at least one evaluation criterion for theapparatus to determine whether to initiate an access procedure with the network node; and determining 204, based on the at least one network energy saving modeparameter and the at least one evaluation criterion, whether to initiate the access procedure with the network node.The apparatus 700 therefore comprises means for:determining 300 at least one network energy saving mode parameter of thenetwork node; determining 302 at least one evaluation criterion for an apparatus to determinewhether to initiate an access procedure with the network node; andtransmitting 304 to the apparatus the at least one network energy saving mode parameter of the network node and the at least one evaluation criterion for the apparatus.The computer program 706 may arrive at the apparatus via any suitable deliverymechanism 708. The delivery mechanism 708 may be, for example, a machine-readablemedium, a computer-readable medium, a non-transitory computer-readable storage medium, a computer program product, a memory device, a record medium such as a Compact Disc Read-Only Memory (CD-ROM) or a Digital Versatile Disc (DVD) or a solid- state memory, an article of manufacture that comprises or tangibly embodies thecomputer program 706. The delivery mechanism may be a signal configured to reliablytransfer the computer program 706. The apparatus may propagate or transmit thecomputer program 706 as a computer data signal.The computer program 706 can comprise computer program instructions for causing adata node to perform at least the following or for performing at least the following: receiving 200, from a network node, at least one network energy saving modeparameter of the network node; receiving 202, from the network node, at least one evaluation criterion for theapparatus to determine whether to initiate an access procedure with the network node; and determining 204, based on the at least one network energy saving modeparameter and the at least one evaluation criterion, whether to initiate the access procedure with the network node.The computer program 706 can comprise computer program instructions for causing anML node to perform at least the following or for performing at least the following: determining 300 at least one network energy saving mode parameter of thenetwork node; determining 302 at least one evaluation criterion for an apparatus to determinewhether to initiate an access procedure with the network node; andtransmitting 304 to the apparatus the at least one network energy saving mode parameter of the network node and the at least one evaluation criterion for the apparatus. The computer program instructions may be comprised in a computer program, a non- transitory computer readable medium, a computer program product, a machine-readable medium. In some but not necessarily all examples, the computer program instructions may be distributed over more than one computer program.Although the memory 704 is illustrated as a single component / circuitry it may beimplemented as one or more separate components / circuitry some or all of which may be integrated / removable and / or may provide permanent / semi-permanent / dynamic / cached storage.Although the processor 702 is illustrated as a single component / circuitry it may beimplemented as one or more separate components / circuitry some or all of which may beintegrated / removable. The processor 702 may be a single core or multi-core processor.An example of a SIB1 that can be used in examples of the disclosure is given below. TheSIB1 may comprise at least one NES mode parameter of the network node. For example,the SIB1 may comprise NES barring factor (uac-NESBarringFactor). For example, theSIB1 may comprise NES barring time (uac-NESBarringTime). For example, the SIB1may comprise the NES barring factor and the NES barring time.The SIB1 may enable the network node to indicate NES mode parameters for respectiveNES modes (cellBarredNES-Mode1 / cellBarredNES-Mode2 / cellBarredNES-Mode3).The apparatus can save the NES mode parameters, or updated NES mode parameters for each type of mode. Once the apparatus has stored the NES mode parameters for therespective NES modes the network can just send the NES mode and the apparatus canselect the appropriate parameters based on the stored information.-- ASN1START-- TAG-SIB1-STARTSIB1 ::= SEQUENCE { cellSelectionInfo SEQUENCE { q-RxLevMin Q-RxLevMin, q-RxLevMinOffset INTEGER (1..8) OPTIONAL,-- Need Sq-RxLevMinSUL Q-RxLevMin OPTIONAL,-- Need Rq-QualMin Q-QualMin OPTIONAL,-- Need Sq-QualMinOffset INTEGER (1..8) OPTIONAL-- Need S} OPTIONAL, -- CondStandalone cellAccessRelatedInfo CellAccessRelatedInfo, connEstFailureControl ConnEstFailureControl OPTIONAL,-- Need Rsi-SchedulingInfo SI-SchedulingInfo OPTIONAL,-- Need R servingCellConfigCommon ServingCellConfigCommonSIBOPTIONAL, -- Need Rims-EmergencySupport ENUMERATED {true}OPTIONAL, -- Need ReCallOverIMS-Support ENUMERATED {true}OPTIONAL, -- Need Rue-TimersAndConstants UE-TimersAndConstantsOPTIONAL, -- Need Ruac-BarringInfo SEQUENCE { uac-NESBarringFactor UAC-BarringParameterForNES OPTIONAL, -- Need Suac-NESBarringTime UAC-BarringParameterForNES OPTIONAL, -- Need Suac-BarringForCommon UAC-BarringPerCatListOPTIONAL, -- Need Suac-BarringPerPLMN-List UAC-BarringPerPLMN-ListOPTIONAL, -- Need Suac-BarringInfoSetList UAC-BarringInfoSetList, uac-AccessCategory1-SelectionAssistanceInfo CHOICE { plmnCommon UAC-AccessCategory1-SelectionAssistanceInfo, individualPLMNList SEQUENCE (SIZE (2..maxPLMN)) OF UAC- AccessCategory1-SelectionAssistanceInfo }OPTIONAL -- NeedS }OPTIONAL, -- NeedR useFullResumeID ENUMERATED {true}OPTIONAL, -- Need RlateNonCriticalExtension OCTET STRING OPTIONAL, nonCriticalExtension SIB1-v1610-IEs OPTIONAL } SIB1-v1610-IEs ::= SEQUENCE { idleModeMeasurementsEUTRA-r16 ENUMERATED{true}OPTIONAL, -- Need R idleModeMeasurementsNR-r16 ENUMERATED{true}OPTIONAL, -- Need RposSI-SchedulingInfo-r16 PosSI-SchedulingInfo-r16OPTIONAL, -- Need RnonCriticalExtension SIB1-v1630-IEs OPTIONAL } SIB1-v1630-IEs ::= SEQUENCE { uac-BarringInfo-v1630 SEQUENCE { uac-AC1-SelectAssistInfo-r16 SEQUENCE (SIZE (2..maxPLMN)) OF UAC- AC1-SelectAssistInfo-r16 }OPTIONAL, -- Need RnonCriticalExtension SIB1-v1700-IEs OPTIONAL } SIB1-v1700-IEs ::= SEQUENCE { hsdn-Cell-r17 ENUMERATED {true} OPTIONAL,-- Need Ruac-BarringInfo-v1700 SEQUENCE { uac-BarringInfoSetList-v1700 UAC-BarringInfoSetList-v1700 }OPTIONAL, -- CondMINT sdt-ConfigCommon-r17 SDT-ConfigCommonSIB-r17OPTIONAL, -- Need RredCap-ConfigCommon-r17 RedCap-ConfigCommonSIB-r17OPTIONAL, -- Need RfeaturePriorities-r17 SEQUENCE { redCapPriority-r17 FeaturePriority-r17 OPTIONAL,-- Need RslicingPriority-r17 FeaturePriority-r17 OPTIONAL,-- Need Rmsg3-Repetitions-Priority-r17 FeaturePriority-r17OPTIONAL, -- Need R sdt-Priority-r17 FeaturePriority-r17 OPTIONAL-- Need R} OPTIONAL, -- Need Rsi-SchedulingInfo-v1700 SI-SchedulingInfo-v1700OPTIONAL, -- Need RhyperSFN-r17 BIT STRING (SIZE (10)) OPTIONAL,-- Need ReDRX-AllowedIdle-r17 ENUMERATED {true}OPTIONAL, -- Need ReDRX-AllowedInactive-r17 ENUMERATED {true}OPTIONAL, -- Cond EDRX-RCintraFreqReselectionRedCap-r17 ENUMERATED {allowed, notAllowed}OPTIONAL, -- Need ScellBarredNTN-r17 ENUMERATED {barred, notBarred}OPTIONAL, -- Need SnonCriticalExtension SIB1-v1740-IEs OPTIONAL } SIB1-v1740-IEs ::= SEQUENCE { si-SchedulingInfo-v1740 SI-SchedulingInfo-v1740OPTIONAL, -- Need RnonCriticalExtension SEQUENCE {} OPTIONAL } UAC-AccessCategory1-SelectionAssistanceInfo ::= ENUMERATED {a, b, c} UAC-AC1-SelectAssistInfo-r16 ::= ENUMERATED {a, b, c, notConfigured} SDT-ConfigCommonSIB-r17 ::= SEQUENCE { sdt-RSRP-Threshold-r17 RSRP-RangeOPTIONAL, -- Need Rsdt-LogicalChannelSR-DelayTimer-r17 ENUMERATED { sf20, sf40, sf64, sf128,sf512, sf1024, sf2560, spare1} OPTIONAL, -- Need R sdt-DataVolumeThreshold-r17 ENUMERATED {byte32, byte100, byte200, byte400, byte600, byte800, byte1000, byte2000, byte4000, byte8000, byte9000, byte10000, byte12000, byte24000, byte48000, byte96000}, t319a-r17 ENUMERATED { ms100, ms200, ms300, ms400, ms600, ms1000, ms2000, ms3000, ms4000, spare7, spare6, spare5, spare4, spare3, spare2, spare1} } RedCap-ConfigCommonSIB-r17 ::= SEQUENCE { halfDuplexRedCapAllowed-r17 ENUMERATED {true}OPTIONAL, -- Need RcellBarredRedCap-r17 SEQUENCE { cellBarredRedCap1Rx-r17 ENUMERATED {barred, notBarred}, cellBarredRedCap2Rx-r17 ENUMERATED {barred, notBarred} } NES-ConfigCommonSIB ::= SEQUENCE { cellBarredNES SEQUENCE { cellBarredNES-Mode1 ENUMERATED {barred, notBarred}, cellBarredNES-Mode2 ENUMERATED {barred, notBarred}, cellBarredNES-Mode3 ENUMERATED {barred, notBarred} }OPTIONAL, -- Need ROPTIONAL, -- Need R... } FeaturePriority-r17 ::= INTEGER (0..7)-- TAG-SIB1-STOP-- ASN1STOPThe term ‘comprise’ is used in this document with an inclusive not an exclusive meaning.That is any reference to X comprising Y indicates that X may comprise only one Y or may comprise more than one Y. If it is intended to use ‘comprise’ with an exclusive meaning then it will be made clear in the context by referring to “comprising only one...” or by using “consisting”. In this description, the wording ‘connect’, ‘couple’ and ‘communication’ and theirderivatives mean operationally connected / coupled / in communication. It should beappreciated that any number or combination of intervening components can exist (including no intervening components), i.e., so as to provide direct or indirectconnection / coupling / communication. Any such intervening components can includehardware and / or software components. As used herein, the term "determine / determining" (and grammatical variants thereof) can include, not least: calculating, computing, processing, deriving, measuring, investigating, identifying, looking up (for example, looking up in a table, a database or another datastructure), ascertaining and the like. Also, "determining" can include receiving (forexample, receiving information), accessing (for example, accessing data in a memory),obtaining and the like. Also, " determine / determining" can include resolving, selecting,choosing, establishing, and the like.In this description, reference has been made to various examples. The description offeatures or functions in relation to an example indicates that those features or functions are present in that example. The use of the term ‘example’ or ‘for example’ or ‘can’ or ‘may’ in the text denotes, whether explicitly stated or not, that such features or functions are present in at least the described example, whether described as an example or not, and that they can be, but are not necessarily, present in some of or all other examples.Thus ‘example’, ‘for example’, ‘can’ or ‘may’ refers to a particular instance in a class ofexamples. A property of the instance can be a property of only that instance or a property of the class or a property of a sub-class of the class that includes some but not all of theinstances in the class. It is therefore implicitly disclosed that a feature described withreference to one example but not with reference to another example, can where possiblebe used in that other example as part of a working combination but does not necessarilyhave to be used in that other example. Although examples have been described in the preceding paragraphs with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims. Features described in the preceding description may be used in combinations other thanthe combinations explicitly described above.Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not. Although features have been described with reference to certain examples, thosefeatures may also be present in other examples whether described or not.The term ‘a’, ‘an’ or ‘the’ is used in this document with an inclusive not an exclusivemeaning. That is any reference to X comprising a / an / the Y indicates that X may compriseonly one Y or may comprise more than one Y unless the context clearly indicates thecontrary. If it is intended to use ‘a’, ‘an’ or ‘the’ with an exclusive meaning then it will bemade clear in the context. In some circumstances the use of ‘at least one’ or ‘one or more’ may be used to emphasis an inclusive meaning but the absence of these termsshould not be taken to infer any exclusive meaning.The presence of a feature (or combination of features) in a claim is a reference to that feature or (combination of features) itself and also to features that achieve substantiallythe same technical effect (equivalent features). The equivalent features include, forexample, features that are variants and achieve substantially the same result in substantially the same way. The equivalent features include, for example, features that perform substantially the same function, in substantially the same way to achieve substantially the same result. In this description, reference has been made to various examples using adjectives oradjectival phrases to describe characteristics of the examples. Such a description of acharacteristic in relation to an example indicates that the characteristic is present in some examples exactly as described and is present in other examples substantially as described. The above description describes some examples of the present disclosure however those of ordinary skill in the art will be aware of possible alternative structures and method features which offer equivalent functionality to the specific examples of such structures and features described herein above and which for the sake of brevity andclarity have been omitted from the above description. Nonetheless, the above descriptionshould be read as implicitly including reference to such alternative structures and method features which provide equivalent functionality unless such alternative structures or method features are explicitly excluded in the above description of the examples of the present disclosure. Whilst endeavoring in the foregoing specification to draw attention to those features believed to be of importance it should be understood that the Applicant may seekprotection via the claims in respect of any patentable feature or combination of featureshereinbefore referred to and / or shown in the drawings whether or not emphasis has been placed thereon. I / we claim:

Claims

CLAIMS1. An apparatus comprising:at least one processor; and at least one memory storing instructions that, when executed by the at leastone processor, cause the apparatus at least to perform:receiving, from a network node, at least one network energy saving mode parameter of the network node; receiving, from the network node, at least one evaluation criterion for the apparatus to determine whether to initiate an access procedure with the network node; and determining, based on the at least one network energy saving mode parameter and the at least one evaluation criterion, whether to initiate the access procedure with the network node.

2. The apparatus as claimed in claim 1 wherein the at least one network energysaving mode parameter comprises at least one of: a network energy saving barring factor; anetwork energy saving barring time; oran indication of an energy saving mode of the network node.

3. The apparatus as claimed in claim 1 or 2, caused to perform: determining that the at least one evaluation criterion is satisfied; and based on determining that the at least one evaluation criterion is satisfied, initiating the access procedure with the network node.

4. The apparatus as claimed in claim 2, wherein the at least one network energy saving mode parameter comprises at least the network energy saving barring time; and the apparatus is caused to perform: determining that the at least one evaluation criterion is not satisfied; based on determining that the at least one evaluation criterion is not satisfied, determining a time period at least based on the network energy saving barring time; waiting until the determined time period expires before a next attempt to access a cell provided by the network node.

5. The apparatus as claimed in any preceding claim, wherein the at least onenetwork energy saving mode parameter comprises different parameters for different energy saving modes of the network node.

6. The apparatus as claimed in claim 5, wherein the different network energy saving modes comprises at least a first mode and a second mode, wherein a number of active resources at the network node is higher in the first mode than in the second mode.

7. The apparatus of any preceding claim, wherein the at least one network energy saving mode parameter is associated with a specific type of the apparatus.

8. The apparatus of any of claims 2 to 7, wherein the at least one network energysaving mode parameter comprises an indication of the energy saving mode of thenetwork node and the apparatus is caused to perform determining at least one of anetwork energy saving barring factor or a network energy saving barring time, based atleast in part on the indication of the energy saving mode of the network node.

9. The apparatus of any preceding claim, wherein the at least one evaluation criterion comprises a mathematical operation based on the at least one network energy saving mode parameter.

10. The apparatus as claimed in any preceding claim, caused to perform:receiving an update for the at least one network energy saving mode parameter of the network node; updating or replacing the at least one network energy saving mode parameter based on the update.

11. The apparatus as claimed in any preceding claim wherein the at least onenetwork energy saving mode parameter comprises information specific to at least one of: an access category; oran access identity.

12. The apparatus as claimed in any preceding claim wherein the at least onenetwork energy saving mode parameter is received as additional information to unified access control parameters.

13. The apparatus as claimed in any preceding claim, wherein at least one of, the atleast one network energy saving mode parameter of the network node or the at least oneevaluation criterion for the apparatus to determine whether to initiate the access procedure with the network node is received via at least one of: -a broadcast message;- unified access control information;- a master information block; or- a system information block.

14. The apparatus of any preceding claim, wherein the apparatus comprises or is comprised in one of: -a user equipment;- an energy harvesting device;- a reduced capability device;- an internet of things device; or- an ambient internet of things device.

15. A network node comprising:at least one processor; and at least one memory storing instructions that, when executed by the at leastone processor, cause the network node at least to perform:determining at least one network energy saving mode parameter of the network node; determining at least one evaluation criterion for an apparatus to determinewhether to initiate an access procedure with the network node; andtransmitting to the apparatus the at least one network energy saving mode parameter of the network node and the at least one evaluation criterion for the apparatus.

16. The network node as claimed in claim 15 wherein the at least one network energysaving mode parameter comprises at least one of: a network energy saving factor; a network energy saving barring time; or an indication of an energy saving mode of the network node.

17. The network node as claimed in any of claims 15 to 16 wherein the at least onenetwork energy saving mode parameter comprises different parameters for different energy saving modes of the network node.

18. The network node as claimed in any of claims 15 to 17 wherein the differentnetwork energy saving modes comprises at least a first mode and a second mode, wherein a number of active resources at the network node is higher in the first mode than in the second mode.

19. The network node as claimed in any of claims 15 to 18 wherein the at least onenetwork energy saving mode parameter is associated with a specific type of the apparatus.

20. The network node as claimed in any of claims 15 to 19 wherein the at least oneevaluation criterion comprises a mathematical operation based on the at least one network energy saving mode parameter.

21. The network node as claimed in any of claims 15 to 20, caused to perform:determining an update for the at least one network energy saving mode parameter of the network node wherein the update relates to changes in at least one of a current network load or an upcoming network load; transmitting to the apparatus the update to the at least one network energy saving mode parameter.

22. The network node as claimed in any of claims 15 to 21 wherein the at least onenetwork energy saving mode parameter comprises information specific to at least one of: an access category; oran access identity.

23. The network node as claimed in any of claims 15 to 22 wherein the at least onenetwork energy saving mode parameter is transmitted as additional information to unified access control parameters.

24. The network node as claimed in any of claims 15 to 23, wherein the at least onenetwork energy saving mode parameter of the network node is transmitted via at least one of: -a broadcast message;- unified access control information;- a master information block; or- a system information block.

25. The network node as claimed in any of claims 15 to 23, wherein the at least oneevaluation criterion for the apparatus to determine whether to initiate the accessprocedure with the network node is transmitted via at least one of: -a broadcast message;- unified access control information;- a master information block; or- a system information block.

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