Improvements in and relating to non-terrestrial networks (NTN)

Abstract

Operating a User Equipment, UE, where the UE is communicatively connectable to a Non-Terrestrial Network, NTN, the method comprising the step of, in response to a determination of a predetermined cond

Description

The present invention relates to the provision of Non-Terrestrial Network (NTN) access for E-UTRAN loT devices (NB-loT and LTE-M / eMTC). It further relates to specifying adaptation to allow New Radio (NR) to function over NTN. Non-Terrestrial Network access may be through Lower Earth Orbit (LEO), Medium Earth Orbit (MEO) and Geostationary Orbit (GEO), as well as through High-Altitude Platform Systems (HAPS). Figure 1 shows a generic configuration of part of a Non-Terrestrial Network. It includes a User Equipment (UE) 10 operable within a NTN cell 100. The cell 100 is facilitated by the satellite 20, which is operable to communicate with the UE 10 and a gateway 30. The gateway 300 is then further coupled to a base station (gNB or eNB) 40, which is then coupled to a Core network 50. The invention has several aspects to it, which are set out below. Narrowband Internet of Things (NB-loT) is a 3GPP-defined network based on 4G E-UTRAN that supports ultra-low complexity devices with very narrow bandwidth that was introduced in 3GPP Release 13. The use case of NB-loT is to serve massive loT application, where requirements, for instance, are to support enhanced coverage, power-efficient operation and a massive number of devices. Some of the features introduced are: support for enhanced coverage through low bandwidth and extreme amounts of repetitions; and power-efficient operation by allowing the User Equipment (UE) to sleep for very long times, relaxed requirements and more efficient signaling to establish with a cell. Further, prior to 3GPP Release 17, neighbour cell measurements for a NB-loT UE was not specified. This was not introduced for NB-loT as it was imagined that an NB-loT UE should be simple and stationary and only connect to an eNodeB (eNB) to deliver short packets, and as a result connected mode handovers were never defined. This meant that an NB-loT UE would measure cells and select a suitable one when in idle mode and then stay with that cell until moving back to idle mode. If a Radio Link Failure (RLF) is triggered due to mobility, then an NB-loT UE would perform cell selection and then connect to a suitable cell. Thus NB-loT mobility in connected mode would rely on triggering RLF and then measuring other cells. In 3GPP Release 17, enhancements were introduced to improve NB-loT mobility. The enhancements were based on targeting the NB-loT RLF-like mobility by introducing the ability of NB-loT UE to measure neighbouring cells while in connected mode. If RLF is triggered, then the NB-loT UE would already have performed the measurements needed in order to select a suitable cell. This procedure compared to the previous situation is shown in Figure 2, where a) shows the RLF procedure according to Release 17 and b) shows the NB-loT enhancements. In essence, b) includes an extra step of the UE performing measurements of neighbouring cells so that it can be prepared in the event of RLF. The solutions are specified by having neighbour cell measurement criteria that is broadcasted for the UE to apply. In release 1,7 the criteria to perform neighbour cell measurements is that the relaxed monitoring criteria, is fulfilled. The specifications in [TSTS36.331, V17.3.0] are as follows: ------------------------------TS36.331 V17.3.0------------------------------ 5.5.8 Measurements in NB-loT Upon transition to RRC_CONNECTED mode, the UE shall: 1> if neighCellMeasCriteria is present in SystemlnformationBlockType3-NB: 2> set NRSRPRef to the latest result of the serving cell measurement as used for cell selection / reselection evaluation; 2> if the relaxed monitoring criterion defined in TS 36.304 [4] was not fulfilled: 3> start T326 with the value t-MeasureDeltaP; While in RRC_CONNECTED mode, after performing a measurement, the UE shall: 1> in the following use the NRSRP measurement for the measured carrier and nrs-PowerOffsetNonAnchor corresponding to the measured carrier; 1> if neighCellMeasCriteria is present in SystemlnformationBlockType3-NB: 2> if (NRSRPRef - (NRSRP- nrs-PowerOffsetNonAnchor)) >s-MeasureDeltaP'. 3> set NRSRPRef = (NRSRP - nrs-PowerOffsetNonAnchor); 3> start or restart T326 with the value t-MeasureDeltaP; 1> if neighCellMeasCriteria is not present in SystemlnformationBlockType3-NB; or 1> if T326 is running: 2> if (NRSRP - nrs-PowerOffsetNonAnchor) <s-Measurelntra, perform intra-frequency measurements as defined in TS 36.133

[16] ; 2> if (NRSRP - nrs-PowerOffsetNonAnchor) <s-Measurelnter, perform inter-frequency measurements as defined in TS 36.133

[16] . TS36.331 V17.3.0 Where the related information elements are as follows: ------------------------------TS36.331 V17.3.0------------------------------ - SystemlnformationBlockType3-NB The IE SystemlnformationBlockType3-NB contains cell re-selection information common for intrafrequency, and inter-frequency cell re-selection as well as intra-frequency cell re-selection information other than neighbouring cell related. SystemlnformationBlockType3-NB information element — ASN1START SystemInformationBlockType3-NB-rl3 ::= cellReselectionlnfoCommon-rl3 q-Hyst-rl3 dB8, dB10, dB24 b cellReselectionServingFreqlnfo-rl3 s-NonIntraSearch-rl.3 b intraFreqCellReselectionlnfo-rl3 q-RxLevMin-rl3 q-QualMin-rl3 Need OP p-Max-rl3 Need OP s-IntraSearchP-rl.3 t-Reselection-rl3 b freqBandlnfo-rl3 -- Need OR multiBandInfoList-rl3 -- Need OR lateNonCriticalExtension SEQUENCE { SEQUENCE { ENUMERATED { dBO, dBl, dB2, dB3, dB4, dB5, dB6, dB12, dB14, dB16, dB18, dB20, dB22 } SEQUENCE { ReselectionThreshold SEQUENCE { Q-RxLevMin, Q-QualMin-r9 OPTIONAL, P-Max OPTIONAL, ReselectionThreshold, T-Reselection-NB-rl3 NS-PmaxList-NB-rl3 OPTIONAL, SEQUENCE (SIZE (1..maxMultiBands)) OF NS-PmaxList-NB-rl3 OPTIONAL, OCTET STRING OPTIONAL, [[ intraFreqCellReselectionlnfo-vl350 IntraFreqCellReselectionlnfo-NB-vl350 OPTIONAL -- Cond Qrxlevmin J J , [[ intraFreqCellReselectionInfo-vl360 IntraFreqCellReselectionInfo-NB-vl360 OPTIONAL -- Need OR J J r [[ intraFreqCellReselectionInfo-vl430 IntraFreqCellReselectionInfo-NB-vl430 OPTIONAL -- Need OR J J r [[ cellReselectionInfoCommon-vl450 CellReselectionInfoCommon-NB-vl450 OPTIONAL -- Need OR nsss-RRM-Config-r15 npbch-RRM-Config-rl5 NSSS-RRM-Config-NB-r15 ENUMERATED {enabled} OPTIONAL OPTIONAL , -- Need -- Need OR OR connMeasConfig-r17 t-Service-rl7 ConnMeasConfig-NB-r17 TimeOffsetUTC-rl7 OPTIONAL , -- Need OPTIONAL OR -- Need OR IntraFreqCellReselectionInfo-NB-vl350 ::= SEQUENCE { delta-RxLevMin-vl.350 INTEGER (-8..-1) IntraFreqCellReselectionInfo-NB-vl360 ::= SEQUENCE { s-IntraSearchP-vl.3 60 ReselectionThreshold-NB-vl360 IntraFreqCellReselectionInfo-NB-vl430 ::= SEQUENCE { powerClassl4dBm-Offset-rl4 ENUMERATED {dB-6, dB-3, dB3, dB6, dB9, dB12} OPTIONAL, — Need OP ce-AuthorisationOffset-rl4 ENUMERATED {dB5, dB10, dB15, dB20, dB25, dB30, dB35} OPTIONAL — Need OP CellReselectionInfoCommon-NB-vl450 ::= SEQUENCE { s-SearchDeltaP-r!4 ENUMERATED {dB6, dB9, dB12, dB15} ConnMeasConfiq-NB-rl7 ::= SEQUENCE { s-Measurelntra-rl? NRSRP-Range-NB-rl4, s-Measurelnter-rl? NRSRP-Range-NB-rl4 OPTIONAL, — Need OP neighCellMeasCriteria-rl7 SEQUENCE { s-MeasureDeltaP-r!7 ENUMERATED {dB6, dB9, dB12, dB15}, L-MeasureDeltaP-rl7 ENUMERATED {sl5, s30, s45, s60} } OPTIONAL — Need OR — ASN1STOP § SystemlnformationBlockType3-NBfie\d descriptions § ce-AuthorisationOffset § Parameter "Qoffsetauthorization" in TS 36.304 [4]. Value in dB. Value dB5 corresponds to 5 dB, i dB10 corresponds to 10 dB and so on. i If the field is absent, the UE applies the value of ce-authorisationOffset in i SystemlnformationBlockType 1-NB. : multiBandlnfoList § A list of additionalPmax and additionalSpectrumEmission values as defined in TS 36.101 §

[42] , clause 6.2.4F, applicable for the intra-frequency neighbouring NB-loT cells if the UE § selects the frequency band from freqBandlndicator in SystemlnformationBlockType1-NB. § npbch-RRM-Config § For FDD: Configuration for NPBCH-based RRM measurements. See TS 36.214

[24] . § If enabled, NPBCH can be used in addition to NRS for RRM measurements for serving cell. i nsss-RRM-Config i For FDD: Configuration for NSSS-based RRM measurements for the serving cell. i powerClass14dBm-Offset i Parameter "Poffset" in TS 36.304 [4], only applicable for UE supporting powerClassNB- i 14dBm. Value in dB. Value dB-6 corresponds to -6 dB, dB-3 corresponds to -3 dB and so on. i If the field is absent, the UE applies the (default) value of 0 dB for "Poffset" in TS 36.304 [4]. i SystemlnformationBlockType3-NB field descriptions i p-Max i Value applicable for the intra-frequency neighbouring E-UTRA cells. If absent the UE applies i i the maximum power according to the UE capability. q-Hyst.........................................................................................................................................................................................................j i Parameter Qhyst in TS 36.304 [4], Value in dB. Value dB1 corresponds to 1 dB, dB2 i i corresponds to 2 dB and so on. s q-QualMin i Parameter "Qquaimin" in TS 36.304 [4], applicable for intra-frequency neighbour cells. If the field i i is not present, the UE applies the (default) value of negative infinity for Qquaimin. § q-RxLevMin, deita-RxLevMin § Parameter "Qrxievmin" in TS 36.304 [4], applicable for intra-frequency neighbour cells. If delta- i § RxLevMin is not included, actual value Qrxievmin = q-RxLevMin * 2 [dBm]. If deita-RxLevMin is i § included, actual value Qrxievmin = (q-RxLevMin + deita-RxLevMin) * 2 [dBm]. i s-lntraSearchP i Parameter "Sintrasearchp" in TS 36.304 [4]. i In case s-lntraSearchP-v1360 is included, the UE shall ignore s-lntraSearchP (i.e. without i i suffix). i s-Measu reDelta P i Threshold of change in serving cell NRSRP to trigger neighbour cell measurement in i § RRC_CONNECTED state. i s-Measurelnter i NRSRP threshold to trigger inter-frequency neighbour cell measurement in i i RRC_CONNECTED state. If the field is absent in connMeasConfig, the UE applies the value i i of s-Measurelntra. i s-Measurelntra i NRSRP threshold to trigger intra-frequency neighbour cell measurement in i | RRC_CONNECTED state. § s-NonlntraSearch ] Parameter SnonintrasearchP in TS 36.304 [4]. i s-SearchDeltaP i Parameter "SsearchDeitap" in TS 36.304 [4]. This parameter is only applicable for UEs supporting i § relaxed monitoring as specified in TS 36.306 [5]. Value dB6 corresponds to 6 dB, dB9 i § corresponds to 9 dB and so on. i t-MeasureDeltaP i Duration after which the UE is not required to perfom neighbour cell measurement in i i RRC_CONNECTED when s-MeasureDeltaP criterion is fulfilled. § SystemlnformationBlockType3-NB field descriptions i t-Reselection i Parameter "TreselectionNB-ioTjntra" in TS 36.304 [4]. i t-Service i Time information on when a NTN quasi-Earth fixed cell is going to stop serving the area it is i i currently covering. § Conditional presence i Explanation § Qrxlevmin i This field is optionally present, Need OR. if q-RxLevMin is set to the i § minimum value. Otherwise the field is not present. ------------------------------TS36.331 V17.3.0------------------------------ The relaxed monitoring critera is that the received signal strength level is within a threshold of a reference received signal strength level. This is basically to ensure that the UE is not very mobile and not on the cell edge This can be seen in the idle mode specifications which follow [TS36.304]: ------------------------------TS36.304V17.3.0------------------------------ 5.2.4.12 Relaxed monitoring 5.2.4.12.0 Relaxed monitoring measurement rules When the UE is required to perform intra-frequency or inter-frequency measurement according to the measurement rules in clause 5.2.4.2 or 5.2.4.2a, the UE may choose not to perform intra-frequency or inter-frequency measurements when: The relaxed monitoring criterion in clause 5.2.4.12.1 is fulfilled for a period of TsearchDeltaP, and Less than 24 hours have passed since measurements for cell reselection were last performed, and The UE has performed intra-frequency or inter-frequency measurements for at least TsearchDeltaP after selecting or reselecting a new cell. 5.2.4.12.1 Relaxed monitoring criterion The relaxed monitoring criterion is fulfilled when: (SrxleVRef-Srxlev) <SsearchDeltaP Where: Srxlev = current Srxlev value of the serving cell (dB). SrxlevRet = reference Srxlev value of the serving cell (dB), set as follows: After selecting or reselecting a new cell, or If (Srxlev - SrxlevRef) >0, or If the relaxed monitoring criterion has not been met for TsearchDeitap: the UE shall set the value of SrxlevRef to the current Srxlev value of the serving cell; TsearchDeitap = 5 minutes, or the eDRX cycle length if eDRX is configured and the eDRX cycle length is longer than 5 minutes. ------------------------------TS36.304V17.3.0------------------------------ NTN system information As NTN has a number of NTN-specific information elements that are only required when accessing an NTN cell, and also due to the rather large information elements it was agreed that a new system information block (SIB) was needed. In NR NTN, SIB19 contains the required information to access an NTN cell: ------------------------------TS38.331 V17.3.0------------------------------ SIB19 SIB19 contains satellite assistance information for NTN access. SIB19 information element — ASN1START — TAG-SIB1 9-START SIB19-rl7 ::= SEQUENCE ( ntn-Con ,fig-rl7 NTN-Config-rl7 OPTIONAL, -- Need R t-Servi ce-rl7 INTEGER (0..549755813887) OPTIONAL, -- Need R referen .ceLocation-r!7 ReferenceLocation-rl7 OPTIONAL, -- Need R distanc 'eThresh-r!7 INTEGER (0. .65525) OPTIONAL, -- Need R ntn-NeighCellConfigList-rl7 lateNonCriticalExtension NTN-NeighCellConfigList-rl7 OCTET STRING OPTIONAL, OPTIONAL, -- Need R ntn-NeighCellConfigListExt-vl720 NTN-NeighCellConfigList-rl7 OPTIONAL -- Need R J J NTN-NeighCellConfigList-rl7 ::= SEQUENCE ( SIZE (1. .maxCellNTN-rl7) ) OF NTN- NeighCellConfig-rl7 NTN-NeighCellConfig-r!7 ::= SEQUENCE { ntn-Config-rl7 NTN-Config-rl7 OPTIONAL, -- Need R carrierFreg-rl7 ARFCN-ValueNR OPTIONAL, -- Need R physCellId-rl7 PhysCellld OPTIONAL -- Need R — TAG-SIB19-STOP — ASN1STOP i SIB19 field descriptions i distanceThresh i Distance from the serving cell reference location and is used in location-based measurement i i initiation in RRCJDLE and RRCJNACTIVE, as defined in TS 38.304

[20] . Each step represents i i 50m. i ntn-Config i Provides parameters needed for the UE to access NR via NTN access such as Ephemeris data, i i common TA parameters, k_offset, validity duration for UL sync information and epoch. i ntn-NeighCellConfigList, ntn-NeighCellConfigListExt i Provides a list of NTN neighbour cells including their ntn-Config, carrier frequency and PhysCellld. i i This set includes all elements of ntn-NeighCellConfigList and all elements of ntn- i i NeighCellConfigListExt. If ntn-Config is absent for an entry in ntn-NeighCellConfigListExt, the ntn- i i Config provided in the entry at the same position in ntn-NeighCellConfigList applies. i referenceLocation i Reference location of the serving cell provided via NTN quasi-Earth fixed system and is used in i i location-based measurement initiation in RRCJDLE and RRCJNACTIVE, as defined in TS 38.304 i |

[20] , i t-Service i Indicates the time information on when a cell provided via NTN quasi-Earth fixed system is going to i i stop serving the area it is currently covering. The field indicates a time in multiples of 10 ms after i i 00:00:00 on Gregorian calendar date 1 January, 1900 (midnight between Sunday, December 31, i i 1899 and Monday, January 1, 1900). The exact stop time is between the time indicated by the value i i of this field minus 1 and the time indicated by the value of this field. ------------------------------TS38.331 V17.3.0------------------------------ In loT NTN SIB31 contains the required information to access an loT NTN cell: 5 ------------------------------TS36.331 V17.3.0------------------------------ - SystemlnformationBlockType31 10 The IE SystemlnformationBlockType31 contains satellite assistance information for the serving cell. SystemlnformationBlockType31 is only signalled in a NTN cell. SystemlnformationBlockType31 information element — ASN1START 15 SystemInformationBlockType31-rl7 ::= SEQUENCE { servingSatelliteInfo-rl7 ServingSatelliteInfo-rl7, lateNonCriticalExtension OCTET STRING OPTIONAL, ServingSatelliteInfo-rl7 ::= ephemerisInfo-r17 stateVectors orbital Parameters nta-CommonParameters-17 nta-Common-rl7 nta-CommonDrift-rl7 nta-CommonDriftVariation-rl7 SEQUENCE { CHOICE { EphemerisStateVectors-r17 r EphemerisOrbital Parameters-r17 SEQUENCE { INTEGER (0..8316827) INTEGER (-261935..261935) INTEGER (0..29479) OPTIONAL, OPTIONAL, OPTIONAL - Need OP - Need OP - Need OP b ul-SyncValidityDuration-rl7 s900}, epochTime-rl7 startSFN-rl7 startSubErame-rl7 } k-Offset-rl7 k-Mac-rl7 ENUMERATED {s5, slO, sl5, s20, s25, s30, s35, s40, s45, s50, s55, s60, sl20, sl80, s240, SEQUENCE { INTEGER (0..1023), INTEGER (0..9) OPTIONAL, — Need OP INTEGER (0..1023), INTEGER (1..512) OPTIONAL, — Need OP — ASN1STOP SystemlnformationBlockType31 field descriptions epochTime Epoch time of the satellite ephemeris data and common TA parameters, see TS 36.213

[23] . The reference point for epoch time of the serving satellite ephemeris and Common TA parameters is the uplink time synchronization reference point. epochTime is the starting time of a DL subframe indicated by startSFN and startSubframe. For serving cell, the startSFN indicates the current SFN or the next upcoming SFN after the frame where the message indicating the epochTime is received. If the field is absent, the UE uses the starting time of the DL subframe corresponding to the end of the SI window during which the SI message carrying SIB31 is transmitted. E-UTRAN always includes epochTime when SystemlnformationBlockType31 is provided through dedicated signalling. In case of handover or conditional handover, this field is based on the timing of the target cell, i.e. the startSFN and startSubFrame number indicated in this field refers to the SFN and sub-frame of the target cell, and UE considers the target cell epoch time (indicated by the startSFN and startSubFrame in this field) to be the frame nearest to the frame where RRCConnectionReconfiguration message is received. k-Mac Scheduling offset used when downlink and uplink frame timing are not aligned at the eNB, see TS 36.213

[23] , Unit in ms. If the field if absent, the UE uses the (default) value of 0. k-Offset Scheduling offset used in the timing relationships in NTN, see TS 36.213

[23] . Unit in ms. SystemlnformationBlockType31 field descriptions nta-Common Network-controlled common TA, see TS 36.213

[23] . Unit of ps. Step of 32.55208 xio3ps. Actual value = field value * 32.55208 xW3. If the field is absent, the UE uses the (default) value of 0. nta-Common Drift Drift rate of the common TA, see TS 36.213

[23] . Unit of ps / s. Step of 0.2 xio 3 ps / s. Actual value = field value * 0.2 xW 3. If the field is absent, the UE uses the (default) value of 0. nta-CommonDriftVariation Drift rate variation of the common TA, see TS 36.213

[23] . Unit of ps / s2. Step of 0.2 x-| CH ps / s2. Actual value = field value * 0.2 xi 01 If the field is absent, the UE uses the (default) value of 0. orbitalParameters Instantaneous values of the satellite orbital parameters. The signalled values are only valid for the duration as defined by ul-SyncValidityDuration and epochTime. stateVectors Instantaneous values of the satellite state vectors. The signalled values are only valid for the duration as defined by ul-SyncValidityDuration and epochTime. ul-SyncValidityDuration Validity duration of the satellite ephemeris data and common TA parameters, i.e. maximum time duration (from epochTime) during which the UE can apply the satellite ephemeris without acquiring new satellite ephemeris, see TS 36.213

[23] . Unit in second. Value s5 corresponds to 5 seconds, value s10 corresponds to 10 seconds and so on. ------------------------------TS36.331 V17.3.0------------------------------ The system information contains the following: 5 Serving cell Ephemeris elements - which allows UE to calculate the satellite position for doppler and time pre-compensation. This can be of two formats: o PVT format - which describes a (X,Y,Z) position as well as a speed vector (vX, vY, vZ) 10 o Orbital parameters - this describes the orbital movements of the satellite which is then used to infer the satellite position TA common parameters - this provides the common timing advance parameters which is introduced to compensate for the feeder link delays. The signaling consists of (in total taking up 57 bits) 15 o Absolute TA common, taking up 23 bits o Drift of the TA common - how the TA common drifts, i.e the first derivative, taking up 19 bits o Variation of the TA common - how the TA common varies, i.e the second derivative of the TA common, taking up 15 bits Synchronization validity duration - used to define how long the ephemeris and TA common is valid Epoch time - when the synchronization validity duration should start K-Offset - scheduling offset for timing relationship in NTN K-Mac - Scheduling offset used when the downlink and uplink frame timing is not aligned NR NTN specific information also include (as part of TS38.331): o T-Service (signaled in SIB3 in loT NTN) o Reference location and distance threshold - used for location-based measurement initiation in RRC IDLE and RRC Connected mode o Neighbour cell ephemeris ■ This is used for idle mode measurements NTN System information acquisition As the ephemeris constantly changes due to the movement of the NTN payload, there is a need to make sure that the UE is correctly synchronized. Thus, whenever UE is connected to an eNB, the UE needs to read the system information. There is furthermore a timer (T317) associated with the ephemeris element that is started every time SIB31 is read. At expiry of T317, the UE is no longer considered synchronized and it will have to re-acquire SIB31 in order to stay synchronized. In NR NTN, the UE shall ensure that it has a recent ephemeris (SIB19 in NR) by reading the SIB in time by UE implementation. In loT NTN, since an loT UE (LTE-M and NB-loT UE) is not expected to be able to acquire system information in connected mode, the UE tunes away and is likely unreachable while reading SIB31. If the loT NTN UE is unable to read the SIB31 within a timer (T318) with a configured duration, the UE performs RLF similar to other cases where Radio Link Failure (RLF) is performed. Global navigation satellite system (GNSS) measurements in loT NTN Both loT NTN and NR NTN are heavily reliant on GNSS in order to synchronize in frequency and in time, as well as to determine correct configuration and whether the UE is allowed to operate in the cell or not. However, due to the nature of how GNSS is usually in a separate part of the device and that GNSS operation is not standardized, it is not specified when a UE shall perform GNSS measurement in the current specification. It is, rather, specified as a requirement that the UE shall have a recent and precise enough GNSS position. For instance, the UE is required to have determined its own position to be used for time and frequency-synchronization and in loT NTN the UE is required to report its GNSS validity duration in certain RRC messages. Furthermore, if the GNSS is deemed to be invalid and the UE is in connected mode, the UE shall move to idle mode. This operation can be seen in Figure 3, (a) where the UE is released (i.e. moved to RRC Idle mode) by the eNB. In Figure 3 (b), the UE releases itself. ----------------------TS36.331 V17.3.0---------------------- 5.3.3.21 UE actions upon indication of out-of-date GNSS position Upon indication that the GNSS position has become out-of-date while in RRC_CONNECTED, the UE shall: 1> perform the actions upon leaving RRC_CONNECTED as specified in 5.3.12, with release cause 'other'. ----------------------TS36.331 V17.3.0---------------------- In the most recent standardisation discussion, some agreements have been reached and these are set out below: Agreement (RAN1#109-e) At least the following options can be considered on GNSS measurement in connected for potential enhancements for improved GNSS operations: • Option 1: UE re-acquires GNSS position fix during RLF procedure • Option 2: UE re-acquires GNSS position fix with a new gap Note: this does not imply that a Rel-18 loT NTN UE is mandated to support one or both of the options. Agreement (RAN1#109-e) Further study on whether there is a need for potential enhancements on the following for long connection time • UE triggered GNSS measurement. • Network triggered GNSS measurement. Agreement (RAN1#110-e) When eNB triggers UE to make GNSS measurements, UE re-acquires GNSS position fix • FFS details of signalling • FFS how UE reports GNSS assistance information after eNB trigger and the detailed content • Note: further discuss whether a UE is expected to handle all eNB triggers Agreement (RAN#110b-e) Support eNB to at least aperiodically trigger UE to make GNSS measurement. Agreement (RAN#110b-e) If eNB aperiodically triggers UE to make GNSS measurement, a MAC CE is used. Agreement (RAN#111) For GNSS measurement in RRC connected, if eNB aperiodically triggers connected UE to make GNSS measurement, UE can re-acquire GNSS position fix with a gap • FFS details of gap configuration The UE may re-acquire GNSS autonomously (when configured by the network) if UE does not receive eNB trigger to make GNSS measurement • FFS based on configured timing One of the options considered is to introduce measurement gaps where the UE may perform GNSS measurements. In Rel-18 loT NTN, 3GPP is working on methods to specify connected mode measurements to allow for longer connection times. These are neighbour cell measurements and GNSS measurements. Several proposals on how to put conditions on measuring neighbouring cells have been proposed: Using t-service - The UE thus performs neighbour cell measurements before the satellite will no longer serve the area (this time is given by t-Service) Using distance-based measurements where a UE will measure and check whether the distance to a serving satellite / NTN node / cell and / or a neighbouring satellite / NTN node / cell fulfills some type of condition. Using signaling of the coverage of an upcoming NTN cell To support neighbour cell measurements, it has also been agreed that neighbour cell satellite ephemeris will be provided. For performing connected mode GNSS measurements, it has been agreed (3GPP RAN1#111): For GNSS measurement in RRC connected, if eNB aperiodically triggers connected UE to make GNSS measurement, UE can re-acquire GNSS position fix with a gap • For further study - details of gap configuration The UE may re-acquire GNSS autonomously (when configured by the network) if UE does not receive eNB trigger to make GNSS measurement • For further study based on configured timing This means that the UE will perform GNSS measurements in so-called measurement gaps that are configured by the network autonomously. These measurements may be mandatory based on a broadcasted configuration as this is often how devices are configured in NB-loT networks. Both neighbour cell measurements and GNSS measurements are likely to be very powerconsuming and, in many cases, not needed to be performed for shorter connection times. For instance, for an NB-loT UE to perform neighbour cell measurements, it is relatively time and power consuming. For an NB-loT device, according to the requirements [TS36.133, V18.0.0, Requirements for support of radio resource management], to perform neighbour cell measurements in a terrestrial cell may take from 1.5 seconds up to 300 seconds. It should furthermore especially be considered in a Non-terrestrial Network where power consumption is expected to be high, and where time-consuming procedures need to be carefully considered, as the satellites and, by extension, the cells, are moving rather quickly. Power consumption may also be increased in a non-terrestrial network due to the need to acquire ephemeris of neighbouring cells. As a specific example, if the UE only has a small amount of data to deliver, performing neighbour cell measurements may cause the connection time to be made a lot longer. Therefore, regardless of the location of network nodes and UEs, there is a need to consider whether neighbour cell measurements should be considered or are needed from a service perspective. It is an aim of an embodiment of the present invention to address shortcomings in the prior art, whether mentioned herein or not. According to the present invention there is provided an apparatus and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows. According to a first aspect of the present invention, there is provided a method of operating a User Equipment, UE, where the UE is communicatively connectable to a Non-Terrestrial Network, NTN, the method comprising the step of in response to a determination of a predetermined condition, the UE determines whether to acquire or not to acquire System Information from a System Information Block, SIB. In an embodiment, if the UE determines not to acquire System Information from SIB, it further determines to not make one or more of: a measurement of a neighbouring cell; and a Global navigation satellite system, GNSS, measurement. In an embodiment, the predetermined condition relates to t-service, wherein t-service relates to a time until a satellite does not serve an area where the UE is located and wherein if t-service is within a defined threshold period, then the UE determines to acquire the System Information. In an embodiment, the predetermined condition relates to a distance-based measurement, where the UE determines if a distance to a satellite or NTN node or cell and / or a neighbouring satellite or NTN node is smaller than a defined threshold distance, and, if so, then the UE determines to acquire the System Information. In an embodiment, the predetermined condition relates to the UE determining if it is within the coverage of an upcoming NTN cell In an embodiment, the predefined condition relates to a volume of data traffic to or from the network and if the volume of data traffic is lower than a defined threshold, then the UE determines not to acquire the System Information. In an embodiment, the predefined condition relates to an amount of data an uplink buffer of the UE and if the volume of data is lower than a defined threshold, then the UE determines not to acquire the System Information. In an embodiment, the amount of data in the uplink buffer is calculated based on Medium Access Control, MAC, or upper layer, RRC, buffer size, and the determination is based on a threshold which is configured by the network, a threshold that is hard-coded, or a threshold that is determined by UE. In an embodiment, the predefined condition relates to a volume of data received in a downlink message and the UE is so instructed by the network not to acquire the System Information. In an embodiment, the predefined condition relates to the UE being configured in short data mode and so the UE determines not to acquire the System Information. In an embodiment, the predefined condition relates to certain predefined services or data types or if the UE is required to perform or be involved in certain predefined operations and so the UE determines not to acquire the System Information. According to a second aspect of the present invention, there is provided apparatus arranged to perform the method of the first aspect. An aspect of this invention is to prevent neighbour cell NTN measurements or GNSS measurements from being performed based on certain conditions. Although a few preferred embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes and modifications might be made without departing from the scope of the invention, as defined in the appended claims. For a better understanding of the invention, and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example only, to the accompanying diagrammatic drawings in which: Figure 1 shows a general NTN architecture known in the prior art; Figures 2a) and 2b) show RLF procedures known in the prior art; Figures 3a) and 3b) show GNSS validity operations known in the prior art; Figures 4a) and 4b) show two operations according to embodiments of the invention; Figure 5 shows an operation according to an embodiment of the invention; and Figure 6 shows an operation according to an embodiment of the invention; An embodiment of the invention provides service-based conditions for performing or not performing neighbour cell measurements in a Non-Terrestrial Network. There may be a number of conditions provided which determine whether to perform neighbour cell measurements or not. All embodiments set out herein apply to NR NTN or LTE-M / eMTC NTN. Embodiments may also find utility with other systems not referred to explicitly, but which will be know to the skilled person. In this application, the expression “performing measurements” may also mean “performing measurements, given all other conditions are fulfilled” or “if supported, performing measurements” or “if applicable, performing measurements”, or any other suitable wording. In other words, whether performing measurements may be dependent on other already introduced conditions or independent of already introduced conditions. Wording such as “considering whether to perform neighbour cell measurements” may also be a valid term. In other words, any other conditions for performing measurements such as those given by prior art may still be considered. In some embodiments the conditions are generalized to both GNSS measurements and neighbour cell measurements, and in some conditions only neighbour cell measurements are considered. In one embodiment, the UE will ignore any conditions to perform neighbour cell measurements or GNSS measurements if the traffic to be delivered by the UE or the network is very low. In a further embodiment, the UE can detect the amount of data in the uplink buffer and then decides whether to perform any neighbour cell measurements or GNSS measurements. If, for instance, the buffer size is low or very low, then no measurement is performed. This can be determined by a UE in any of the following ways: The UE calculates the buffer size in Medium Access Control (MAC) or upper layer (RRC buffer size) and determines whether to perform neighbour cell measurements or GNSS measurement. The determination can be performed using a threshold configured by the network, a threshold that is hard-coded, or a threshold that is determined by UE according to some algorithm. The first of these is shown as an example of neighbour cell measurements discussed later and in Figure 4. In another embodiment, the UE will ignore any configurations from the network, to perform neighbour cell measurements or GNSS measurements, if the UE determines that the traffic size exchanged between the network and the UE is below a traffic threshold. In one example, the traffic threshold is preconfigured by the network. In one embodiment, if supported, the UE may postpone performing neighbour cell measurements or GNSS measurements until the UE decides that the traffic size has increased above a predefined threshold. In a further embodiment, in the case where the data is downlink data delivered by the network, the network can indicate to the UE that there is no need to perform any neighbour cell measurements or GNSS measurements, as the data is rather small. This can be indicated in a number of ways: In a paging message In an RRC configuration • This can also be a flag In a newly defined RRC procedure, messages and / or lEs. In a broadcasted message • This can be a flag that instructs all UEs that are initiated by network for downlink data that there is no need to perform any neighbour cell measurements or GNSS measurements In a downlink data packet • This may especially be suitable for an NB-loT UE where data is delivered over NAS and a flag can be added in an RRC message along with the data. This can be seen later. Can also be implicit if the UE is utilizing certain procedures: • For instance, in the case of utilizing RRC Resume and suspend procedure. This means that if the UE is paged and utilizes RRC suspend and resume procedure, the UE does not need to perform neighbour cell measurements or GNSS measurements • Similarly, if the UE is paged and using Early Data Transmission (EDT) procedure, the UE is not required to perform neighbour cell measurements or GNSS measurements In one embodiment, the UE is configured with a short data mode, where most of the uplink data is short (i.e. small data size) and thus the UE does not need to perform neighbour cell measurements or GNSS measurements. This can, for instance, be configured by MME or eNB. Alternatively, it can be based on some historic conditions such as previous data packets. For instance, the UE can be configured in such a mode if the data packets of the previous certain number (X) transmissions have been less than a defined threshold, or if the average packet size is smaller than a defined threshold. For example, this short data mode may be configured by a network. An example of this can be seen in Figure 5. In one embodiment, if supported, the UE may or may not inform the network of its decision to not perform neighbour cell measurements or GNSS measurements. In one example, the UE may provide to the network a cause value for not performing the configured measurements. In one embodiment, if supported, the UE ignores neighbouring cell measurements or GNSS measurements for certain services and / or traffic type. In another embodiment, the UE does not perform neighbour cell measurements or GNSS measurements when the UE needs to perform (or be involved) in specific procedures. For example, these procedures can be tracking area updates (periodic or triggered). If the UE is configured with suspended RRC connection (also known as resuming RRC connection / RRC Resume procedures / utilizing RRCConnectionResume), the UE may be configured to not consider any neighbour cell measurements or GNSS measurements. For example, this can be configured in a broadcast manner (i.e. via system information broadcast, SIB) or for instance in an RRCConnectionRelease message (and / or using any newly defined RRC signaling / messages and / or lEs). An example of this is described later. This can be beneficial for a UE that is configured with a suspended RRC connection state or mode. This is because the UE is not expected to remain in a RRC connected state or mode for a very long time, and the UE may already have performed measurements in idle mode. An example of this is shown in Figure 6. In one embodiment, the UE considers the neighbour cell measurements or GNSS measurements if it has been connected for a period longer than a configured time. For example, this period may be configured by the network. In a further example, the UE starts a timer, whenever it connects to a cell, and once the configured time has been reached, then the UE considers whether to perform neighbour cell measurements. In order to measure neighbouring cells in a non-terrestrial network, there may be a need to read or acquire more System Information, compared to not performing any measurements. Therefore, in one embodiment, if the conditions are fulfilled whereby the UE does not need to perform any neighbour cell measurements, the UE does not need to acquire the related system information for performing the measurements. This system information could, for instance, be neighbouring cell ephemeris, which may or may not be included in a separate System Information Block (SIB). This can save the UE a lot of time and power consumption by not needing to acquire this SIB, as the SIB is also expected to be large since NTN ephemeris is a rather large field. In one embodiment, the UE does not need to perform neighbour cell measurements or GNSS measurements if Early Data Transmission (EDT) is performed. There now follows certain illustrative examples to further describe certain embodiments of the invention. In a first example, the UE will not perform any neighbour cell measurements unless the size of the resulting MAC PDU is larger than a configured threshold: -------------------------TS36.331 V17.3.0 EXAMPLE------------------------------ 5.5.8 Measurements in NB-loT Upon transition to RRC_CONNECTED mode, the UE shall: 1> if neighCellMeasCriteria is present in SystemlnformationBlockType3-NB: 2> set NRSRPRef to the latest result of the serving cell measurement as used for cell selection / reselection evaluation; 2> if the relaxed monitoring criterion defined in TS 36.304 [4] was not fulfilled or for mobile originating calls, if the size of the resulting MAC PDU including total UL data is expected to be larger than or equal to the TBS signalled in tbs-NeighCellMeas: 3> start T326 with the value t-MeasureDeltaP; While in RRC_CONNECTED mode, after performing a measurement, the UE shall: 1> in the following use the NRSRP measurement for the measured carrier and nrs-PowerOffsetNonAnchor corresponding to the measured carrier; 1> if neighCellMeasCriteria is present in SystemlnformationBlockType3-NB: 2> if (NRSRPRef - (NRSRP- nrs-PowerOffsetNonAnchor)) >s-MeasureDeltaP: 3> set NRSRPRef = (NRSRP - nrs-PowerOffsetNonAnchor); 3> start or restart T326 with the value t-MeasureDeltaP; 1> if neighCellMeasCriteria is not present in SystemlnformationBlockType3-NB; or 1> if T326 is running: 2> if (NRSRP - nrs-PowerOffsetNonAnchor) <s-Measurelntra, perform intrafrequency measurements as defined in TS 36.133

[16] ; 2> if (NRSRP - nrs-PowerOffsetNonAnchor) <s-Measurelnter, perform interfrequency measurements as defined in TS 36.133

[16] . <...OMITTED...> - SystemlnformationBlockType3-NB The IE SystemlnformationBlockType3-NB contains cell re-selection information common for intrafrequency, and inter-frequency cell re-selection as well as intra-frequency cell re-selection information other than neighbouring cell related. The following is a representation of SystemlnformationBlockType3-NB information element — ASN1START SystemInformationBlockType3-NB-rl3 ::= SEQUENCE { cellReselectionInfoCommon-rl.3 SEQUENCE { q-Hyst-rl.3 ENUMERATED { dBO, dBl, dB2, dB3, dB4, dB5, dB6, dB8, dB10, dB12, dB14, dB16, dB18, dB20, dB22, dB24 } b cellReselectionServingFreqInfo-rl3 SEQUENCE { s-NonIntraSearch-rl.3 ReselectionThreshold }, intraFreqCellReselectionlnf o-rl.3 q-RxLevMin-rl3 q-QualMin-rl3 p-Max-rl3 s-IntraSearchP-rl3 t-Reselection-rl3 b freqBandlnfo-rl3 multiBandInfoList-rl3 lateNonCriticalExtension [[ intraFreqCellReselectionlnfo-vl350 -- Cond Qrxlevmin J J r [[ intraFreqCellReselectionInfo-vl360 -- Need OR J J r [[ intraFreqCellReselectionInfo-vl430 -- Need OR J J r [[ cellReselectionInfoCommon-vl450 -- Need OR J J r [[ nsss-RRM-Config-rl5 npbch-RRM-Config-rl5 J J r [[ connMeasConfig-rl7 t-Service-rl7 J J r [[ connMeasConfig-rl8 J J SEQUENCE { Q-RxLevMin, Q-QualMin-r9 OPTIONAL, P-Max OPTIONAL, ReselectionThreshold, T-Reselection-NB-rl3 NS-PmaxList-NB-rl3 Need OP Need OP OPTIONAL, — Need OR SEQUENCE (SIZE (1..maxMultiBands)) OF NS-PmaxList-NB-rl3 OPTIONAL, — Need OR OCTET STRING OPTIONAL, IntraFreqCellReselectionlnfo-NB-vl350 OPTIONAL IntraFreqCellReselectionInfo-NB-vl360 OPTIONAL IntraFreqCellReselectionInfo-NB-vl430 OPTIONAL CelIReselectionlnfoCommon-NB-vl450 OPTIONAL NSSS-RRM-Co ENUMERATED nfig-NB-rl5 {enabled} OPTIONAL, OPTIONAL -- Need -- Need OR OR ConnMeasCon fig-NB-rl7 OPTIONAL, -- Need OR TimeOffsetUTC-rl7 OPTIONAL -- Need OR ConnMeasCon fig-NB-rl8 OPTIONAL -- Need OR IntraFreqCellReselectionInfo-NB-vl350 ::= delta-RxLevMin-vl350 SEQUENCE { INTEGER (-8..-1) IntraFreqCellReselectionInfo-NB-vl360 ::= s-IntraSearchP-vl360 SEQUENCE { ReselectionThreshold-NB-vl360 IntraFreqCellReselectionInfo-NB-vl430 ::= SEQUENCE { powerClassl4dBm-Offset-rl4 ENUMERATED {dB-6, dB-3, dB3, dB6, dB9, dB12} OPTIONAL, — Need OP ce-AuthorisationOffset-rl4 ENUMERATED {dB5, dB10, dB15, dB20, dB25, dB30, dB35} OPTIONAL — Need OP } CelIReselectionlnfoCommon-NB-vl450 s-SearchDeltaP-rl4 } SEQUENCE { ENUMERATED {dB6, dB9, dB12, dB15} ConnMeasConfig-NB-rl7 ::= SEQUENCE { s-MeasureIntra-rl7 NRSRP-Range-NB-rl4, s-MeasureInter-rl7 NRSRP-Range-NB-rl4 OPTIONAL, — Need OP neighCellMeasCriteria-rl7 SEQUENCE { s-MeasureDeltaP-rl7 ENUMERATED {dB6, dB9, dB12, dB15}, t-MeasureDeltaP-rl7 ENUMERATED {sl5, s30, s45, s60} } OPTIONAL — Need OR } ConnMeasConfig-NB-rl8 ::= SEQUENCE { tbs-NeighCellMeas-rl8 ENUMERATED {true} } — ASN1STOP SystemlnformationBlockType3-NB field descriptions § SystemlnformationBlockType3-NB field descriptions i ce-AuthorisationOffset i Parameter "Qoffsetauthorization" in TS 36.304 [4]. Value in dB. Value dB5 corresponds to 5 dB, i i dB10 corresponds to 10 dB and so on. § If the field is absent, the UE applies the value of ce-authorisationOffset in i § SystemlnformationBlockType1-NB. i muitiBandinfoList i A list of additionalPmax and additionalSpectrumEmission values as defined in TS 36.101 i i

[42] , clause 6.2.4F, applicable for the intra-frequency neighbouring NB-loT cells if the UE i i selects the frequency band from freqBandlndicator in SystemlnformationBlockTypel -NB. i npbch-RRM-Config i For FDD: Configuration for NPBCH-based RRM measurements. See TS 36.214

[24] . i If enabled, NPBCH can be used in addition to NRS for RRM measurements for serving cell. § nsss-RRM-Config § For FDD: Configuration for NSSS-based RRM measurements for the serving cell. § powerClass14dBm-Offset § Parameter "Poffset" in TS 36.304 [4], only applicable for UE supporting powerClassNB- i § 14dBm. Value in dB. Value dB-6 corresponds to -6 dB, dB-3 corresponds to -3 dB and so on. i § If the field is absent, the UE applies the (default) value of 0 dB for "Poffset" in TS 36.304 [4]. § p-Max § Value applicable for the intra-frequency neighbouring E-UTRA cells. If absent the UE applies i § the maximum power according to the UE capability. q-Hyst.........................................................................................................................................................................................................] i Parameter Qhyst in TS 36.304 [4], Value in dB. Value dB1 corresponds to 1 dB, dB2 i i corresponds to 2 dB and so on. i q-QualMin i Parameter "Qquaimin" in TS 36.304 [4], applicable for intra-frequency neighbour cells. If the field i i is not present, the UE applies the (default) value of negative infinity for Qquaimin. § q-RxLevMin, delta-RxLevMin § Parameter "Qrxievmin" in TS 36.304 [4], applicable for intra-frequency neighbour cells. If delta- i § RxLevMin is not included, actual value Qrxievmin = q-RxLevMin * 2 [dBm]. If delta-RxLevMin is i § included, actual value Qrxievmin = (q-RxLevMin + delta-RxLevMin) * 2 [dBm]. § s-lntraSearchP § Parameter "Sintrasearchp" in TS 36.304 [4]. § In case s-lntraSearchP-v1360 is included, the UE shall ignore s-lntraSearchP (i.e. without i § suffix). § SystemlnformationBlockType3-NB field descriptions i s-MeasureDeltaP i Threshold of change in serving cell NRSRP to trigger neighbour cell measurement in i | RRC_CONNECTED state. i s-Measurelnter i NRSRP threshold to trigger inter-frequency neighbour cell measurement in i i RRC_CONNECTED state. If the field is absent in connMeasConfig, the UE applies the value i i of s-Measurelntra. i s-Measurelntra i NRSRP threshold to trigger intra-frequency neighbour cell measurement in i | RRC_CONNECTED state. § s-NoniniraSearch j Parameter SnonintrasearchP in TS 36.304 [4]. i s-SearchDeltaP i Parameter "SsearchDeitap" in TS 36.304 [4]. This parameter is only applicable for UEs supporting i i relaxed monitoring as specified in TS 36.306 [5]. Value dB6 corresponds to 6 dB, dB9 i i corresponds to 9 dB and so on. i t-MeasureDeltaP i Duration after which the UE is not required to perfom neighbour cell measurement in i i RRC_CONNECTED when s-MeasureDeltaP criterion is fulfilled. i t-Reselection i Parameter "TreselectionNB-ioTjntra" in TS 36.304 [4]. i t-Service i Time information on when a NTN quasi-Earth fixed cell is going to stop serving the area it is i i currently covering. § ibs-NeighCeHMeas § Threshold of Transport block size condition to trigger neighbour cell measurements. In a second example, it is indicated to the UE that it does not need to perform any neighbour cell measurements in a DLlnformation-NB message: 5 ------------------------------TS36.331 V17.3.0 EXAMPLE------------------------------ - DLlnformationTransfer-NB The DLlnformationTransfer-NB message is used for the downlink transfer of NAS dedicated information. 10 Signalling radio bearer: SRB1 or SRBIbis RLC-SAP: AM Logical channel: DCCH Direction: E UTRAN to UE The following is a DLlnformationTransfer-NB message: — ASN1START DLInformationTransfer-NB ::= SEQUENCE ( rrc-Transactionidentifier criticalExtensions cl dllnformationTrans f er-rl.3 sparel NULL b criticalExtensions Future } RRC-Transactionldenti fier, CHOICE { CHOICE { DLInf ormationTrans fer-NB-rl.3-IEs , SEQUENCE {} DLInformationTransfer-NB-rl3-IEs ::= dedicatedInfoNAS-rl.3 lateNonCriticalExtension dlInformationTrans fer-18 SEQUENCE { DedicatedlnfoNAS, OCTET STRING OPTIONAL, DLInformationTransfer-NB-rl8-IEs OPTIONAL DLInformationTransfer-NB-rl8-IEs ::= neighbourCellMeasurement-rl8 lateNonCriticalExtension nonCriticalExtension SEQUENCE { ENUEMRATED {true} OCTET STRING SEQUENCE {} OPTIONAL, OPTIONAL, OPTIONAL — ASN1STOP In a third example, neighbour cell measurements are not performed if the UE is performing RRC resume: ------------------------------ 36.331 V17.3.0 EXAMPLE------------------------------ 5.5.8 Measurements in NB-loT Upon transition to RRC_CONNECTED mode, the UE shall: 1> if neighCellMeasCriteria is present in SystemlnformationBlockType3-NB: 2> set NRSRPRef to the latest result of the serving cell measurement as used for cell selection / reselection evaluation; 2> if the relaxed monitoring criterion defined in TS 36.304 [4] was not fulfilled or if neighCellMeasResumeCriteria is true and the UE is not resuming from an RRC suspend state: 3> start T326 with the value t-MeasureDeltaP; While in RRC_CONNECTED mode, after performing a measurement, the UE shall: 1> in the following use the NRSRP measurement for the measured carrier and nrs-PowerOffsetNonAnchor corresponding to the measured carrier; 1> if neighCellMeasCriteria is present in SystemlnformationBlockType3-NB: 2> if (NRSRPRef - (NRSRP- nrs-PowerOffsetNonAnchor)) >s-MeasureDeltaP: 3> set NRSRPRef = (NRSRP - nrs-PowerOffsetNonAnchor); 3> start or restart T326 with the value t-MeasureDeltaP; 1> if neighCellMeasCriteria is not present in SystemlnformationBlockType3-NB; or 1> if T326 is running: 2> if (NRSRP - nrs-PowerOffsetNonAnchor) <s-Measurelntra, perform intra-frequency measurements as defined in TS 36.133

[16] ; 2> if (NRSRP - nrs-PowerOffsetNonAnchor) <s-Measurelnter, perform inter-frequency measurements as defined in TS 36.133

[16] . The corresponding ANSI code is as follows: SystemlnformationBlockType3-NB The IE SystemlnformationBlockType3-NB contains cell re-selection information common for intra-frequency, and inter-frequency cell re-selection as well as intra-frequency cell re-selection information other than neighbouring cell related. The following is the SystemlnformationBlockType3-NB information element: — ASN1START Systemlnf ormationBlockType.3-NB-rl.3 cellReselectionlnfoCommon-r13 q-Hyst-rl.3 dB8, dB10, dB24 b cellReselectionServingFreqlnf o-rl.3 s-NonIntraSearch-rl.3 b intraFreqCellReselectionlnf o-rl.3 q-RxLevMin-rl.3 q-QualMin-rl.3 p-Max-rl.3 s-IntraSearchP-rl.3 t-Reselection-rl.3 b f reqBandlnf o-rl.3 multiBandInfoList-rl.3 lateNonCriticalExtension [[ intraFreqCellReselectionlnfo-vl350 -- Cond Qrxlevmin J J r [ [ intraFreqCellReselectionInfo-vl.360 -- Need OR J J r [[ intraFreqCellReselectionInfo-vl430 -- Need OR J J r [[ cellReselectionInfoCommon-vl450 -- Need OR J J r [[ nsss-RRM-Config-rl5 npbch-RRM-Config-rl5 SEQUENCE { SEQUENCE { ENUMERATED { dBO, dBl, dB2, dB3, dB4, dB5, dB6, dB12, dB14, dB16, dB18, dB20, dB22, } SEQUENCE { ReselectionThreshold SEQUENCE { Q-RxLevMin, Q-QualMin-r9 OPTIONAL,— Need OP P-Max OPTIONAL, — Need OP ReselectionThreshold, T-Reselection-NB-rl3 NS-PmaxList-NB-rl3 OPTIONAL, — Need OR SEQUENCE (SIZE (1..maxMultiBands)) OF NS-PmaxList-NB-rl3 OPTIONAL, — Need OR OCTET STRING OPTIONAL, IntraFreqCellReselectionlnfo-NB-vl350 OPTIONAL IntraFreqCellReselectionInfo-NB-vl360 OPTIONAL IntraFreqCellReselectionInfo-NB-vl430 OPTIONAL CellReselectionlnfoCommon-NB-vl450 OPTIONAL NSSS-RRM-Config-NB-rl5 OPTIONAL, — Need OR ENUMERATED {enabled} OPTIONAL — Need OR ] J, [[ connMeasConfig-rl7 t-Service-rl7 J J r [[ connMeasConfig-rl8 J J ConnMeasConfig-NB-r17 TimeOffsetUTC-rl7 ConnMeasConfig-NB-r18 OPTIONAL, — Need OR OPTIONAL — Need OR OPTIONAL -- Need OR IntraFreqCellReselectionInfo-NB-vl350 ::= delta-RxLevMin-vl.350 } SEQUENCE { INTEGER (-8..-1) IntraFreqCellReselectionInfo-NB-vl360 ::= SEQUENCE { s-IntraSearchP-vl.3 60 ReselectionThreshold-NB-vl360 } IntraFreqCellReselectionInfo-NB-vl430 ::= SEQUENCE { powerClassl4dBm-Offset-rl4 ENUMERATED {dB-6, dB-3, dB3, dB6, dB9, dB12} OPTIONAL, — Need OP ce-AuthorisationOffset-rl4 ENUMERATED {dB5, dB10, dB15, dB20, dB25, dB30, dB35} OPTIONAL — Need OP } CellReselectionInfoCommon-NB-vl450 ::= SEQUENCE { s-SearchDeltaP-rl4 ENUMERATED {dB6, dB9, dB12, dB15} } ConnMeasConfig-NB-rl7 ::= SEQUENCE { s-MeasureIntra-rl7 NRSRP-Range-NB-rl4, s-MeasureInter-rl7 NRSRP-Range-NB-rl4 OPTIONAL, — Need OP neighCellMeasCriteria-rl7 SEQUENCE { s-MeasureDeltaP-rl7 ENUMERATED {dB6, dB9, dB12, dB15}, t-MeasureDeltaP-rl7 ENUMERATED {sl5, s30, s45, s60} } OPTIONAL — Need OR } ConnMeasConfig-NB-r18 SEQUENCE neighCellMeasResumeCriteria } { ENUMERATED {true} OPTIONAL, — Need OP — ASN1STOP § SysieminformaiionBjockfype3^ descriptions § ce-AuthorisationOffset § Parameter "Qoffsetauthorization" in TS 36.304 [4]. Value in dB. Value dB5 corresponds to 5 dB, § dB10 corresponds to 10 dB and so on. § If the field is absent, the UE applies the value of ce-authorisationOffset in § SystemlnformationBlockType 1-NB. i multiBandlnfoList i A list of additionalPmax and additionalSpectrumEmission values as defined in TS 36.101

[42] , § clause 6.2.4F, applicable for the intra-frequency neighbouring NB-loT cells if the UE selects the § frequency band from freqBandlndicator in SystemlnformationBlockType1-NB. i neighCellMeasResumeCriteria i Determines whether a UE shall perform neighbour cell measurement after having resumed an i RRC connection. i SystemlnformationBlockType3-NB field descriptions i npbch-RRM-Config i For FDD: Configuration for NPBCH-based RRM measurements. See TS 36.214

[24] . i If enabled, NPBCH can be used in addition to NRS for RRM measurements for serving cell. i nsss-RRM-Config i For FDD: Configuration for NSSS-based RRM measurements for the serving cell. i powerClass14dBm-Offset i Parameter "Poffset" in TS 36.304 [4], only applicable for UE supporting powerClassNB-14dBm. i Value in dB. Value dB-6 corresponds to -6 dB, dB-3 corresponds to -3 dB and so on. If the field i is absent, the UE applies the (default) value of 0 dB for "Poffset" in TS 36.304 [4]. § p-Max § Value applicable for the intra-frequency neighbouring E-UTRA cells. If absent the UE applies § the maximum power according to the UE capability. q-Hyst i Parameter Qhyst in TS 36.304 [4], Value in dB. Value dB1 corresponds to 1 dB, dB2 i corresponds to 2 dB and so on. : q-QualMin i Parameter "Qquaimin" in TS 36.304 [4], applicable for intra-frequency neighbour cells. If the field i is not present, the UE applies the (default) value of negative infinity for Qquaimin. i q-RxLevMin, delta-RxLevMin i Parameter "Qrxievmin" in TS 36.304 [4], applicable for intra-frequency neighbour cells. If delta-i RxLevMin is not included, actual value Qrxievmin = q-RxLevMin * 2 [dBm]. If delta-RxLevMin is i included, actual value Qrxievmin = (q-RxLevMin + delta-RxLevMin) * 2 [dBm]. i s-lntraSearchP i Parameter "Sintrasearchp" in TS 36.304 [4]. i In case s-lntraSearchP-v1360 is included, the UE shall ignore s-lntraSearchP (i.e. without i suffix). § s-MeasurebeitaP § Threshold of change in serving cell NRSRP to trigger neighbour cell measurement in | RRC_CONNECTED state. i s-Measurelnter i NRSRP threshold to trigger inter-frequency neighbour cell measurement in § RRC_CONNECTED state. If the field is absent in connMeasConfig, the UE applies the value of § s-Measurelntra. i s-Measurelntra i NRSRP threshold to trigger intra-frequency neighbour cell measurement in § RRC_CONNECTED state. § SystemlnformationBlockType3-NB field descriptions i s-NonlntraSearch s Parameter SnonintrasearchP in TS 36.304 [4]. i s-SearchDeltaP i Parameter "SsearchDeitap" in TS 36.304 [4]. This parameter is only applicable for UEs supporting i relaxed monitoring as specified in TS 36.306 [5]. Value dB6 corresponds to 6 dB, dB9 i corresponds to 9 dB and so on. i t-MeasureDeitaP i Duration after which the UE is not required to perfom neighbour cell measurement in i RRC_CONNECTED when s-MeasureDeltaP criterion is fulfilled. § i-Reseieciion § Parameter "TreselectionNB-ioTjntra" in TS 36.304 [4]. § t-Service § Time information on when a NTN quasi-Earth fixed cell is going to stop serving the area it is § currently covering. i tbs-NeighCellMeas i Threshold of Transport block size condition to trigger neighbour cell measurements. In a fourth example, the UE UE does not perform GNSS measurements if the buffer is larger than a threshold: ------------------------------TS36.331 V17.2.0 EXAMPLE------------------------------ 5.5.X GNSS measurements for NTN The purpose of this procedure is for the UE to perform GNSS measurements in order for the UE to stay synchronized. The UE shall: 1> if gnss-MeasurementGaps is present in SystemlnformationBlockType3(-NB) and for mobile originating calls, if the size of the resulting MAC PDU including total UL data is expected to be larger than or equal to the TBS signalled in tbs-NeighCellMeas, if signalled: 2> perform GNSS measurement in the measurement gap as indicated by gnss-MeasurementGaps before the expiry of the GNSS validity duration At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as ‘component’, ‘module’ or ‘unit’ used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive. Throughout this specification, the term “comprising” or “comprises” means including the component(s) specified but not to the exclusion of the presence of others. Attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. 27 05 25

Claims

1. A method of operating a User Equipment, UE, where the UE is communicatively connectable to a Non-Terrestrial Network, NTN, the method comprising the step of in response to 5 a determination of a predetermined condition, the UE determines whether to acquire or not toacquire System Information from a System Information Block, SIB wherein if the UE determines not to acquire System Information from SIB, it further determines to not make one or more of:a measurement of a neighbouring cell; anda Global navigation satellite system, GNSS, measurement.10 2. The method of any preceding claim wherein the predetermined condition relates to t-service, wherein t-service relates to a time until a satellite does not serve an area where the UE is located and wherein if t-service is within a defined threshold period, then the UE determines to acquire the System Information.

3. The method of any preceding claim wherein the predetermined condition relates to a 15 distance-based measurement, where the UE determines if a distance to a satellite or NTN nodeor cell and / or a neighbouring satellite or NTN node is smaller than a defined threshold distance, and, if so, then the UE determines to acquire the System Information.

4. The method of any preceding claim wherein the predetermined condition relates to the UE determining if it is within the coverage of an upcoming NTN cell20 5. The method of any preceding claim wherein the predefined condition relates to a volume ofdata traffic to or from the network and if the volume of data traffic is lower than a defined threshold, then the UE determines not to acquire the System Information.

6. The method of any preceding claim wherein the predefined condition relates to an amount of data an uplink buffer of the UE and if the volume of data is lower than a defined threshold, then25 the UE determines not to acquire the System Information.

7. The method of claim 6 wherein the amount of data in the uplink buffer is calculated based on Medium Access Control, MAC, or upper layer, RRC, buffer size, and the determination is based on a threshold which is configured by the network, a threshold that is hard-coded, or a threshold that is determined by UE.30 8. The method of any preceding claim wherein the predefined condition relates to a volume ofdata received in a downlink message and the UE is so instructed by the network not to acquire the System Information.

9. The method of any preceding claim wherein the predefined condition relates to the UEbeing configured in short data mode and so the UE determines not to acquire the SystemInformation.

10. The method of any preceding claim wherein the predefined condition relates to certain5 predefined services or data types or if the UE is required to perform or be involved in certainpredefined operations and so the UE determines not to acquire the System Information.

11. Apparatus arranged to perform the method of any preceding claim.27 05 25

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