Measurement configuration

Abstract

According to an example aspect of the present invention, there is provided an apparatus configured to determine an energy state of the apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and request from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

Description

MEASUREMENT CONFIGURATIONCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is related to and claims the priority of Finland Patent ApplicationNo. 20236014, filed September 8, 2023, the entirety of which is hereby incorporated herein by reference.FIELD

[0002] The present disclosure relates to cellular communications and measurements therein.BACKGROUND

[0003] User equipments, UEs, moving in a coverage area of a cellular communication system are configured to measure received signal strengths of their serving cell, as well as other nearby cells, which may be referred to as neighbouring cells. By observing trends in these signal strengths, the UE and / or the network may determine when the UE is moving toward an edge of a coverage area of the serving cell and toward a coverage area of one of the neighbouring cells.

[0004] A handover or switching process from the serving cell to the neighbouring cell, or beam, may be initiated based on the measurements of the signal strengths. Thus these measurements need to be performed often enough, to enable initiation of the handover or switching process in time, before a radio link between the UE and the serving cell, or beam, is severed due to UE movement.SUMMARY

[0005] According to some aspects, there is provided the subject-matter of the independent claims. Some embodiments are defined in the dependent claims. The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments, examples and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention.

[0006] According to a first aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to determine an energy state of the apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and request from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

[0007] According to a second aspect of the present disclosure, there is provided an apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to send to a user equipment at least two energy thresholds which define at least a low energy state, an intermediate energy state and a high energy state, receive from a user equipment a request for a neighbouring and / or serving cell measurement period modification, and send to the user equipment a message indicating the neighbouring and / or serving cell measurement period modification as a response to the request fulfilling at least one condition.

[0008] According to a third aspect of the present disclosure, there is provided a method, comprising determining an energy state of an apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and requesting from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

[0009] According to a fourth aspect of the present disclosure, there is provided a method comprising sending to a user equipment at least two energy thresholds which define at least a low energy state, an intermediate energy state and a high energy state, receiving from a user equipment a request for a neighbouring and / or serving cell measurement period modification, and sending to the user equipment a message indicating the neighbouring and / or serving cell measurement period modification as a response to the request fulfilling at least one condition.

[0010] According to a fifth aspect of the present disclosure, there is provided an apparatus comprising means for determining an energy state of an apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and requesting from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

[0011] According to a sixth aspect of the present disclosure, there is provided an apparatus comprising means for sending to a user equipment at least two energy thresholds which define at least a low energy state, an intermediate energy state and a high energy state, receiving from a user equipment a request for a neighbouring and / or serving cell measurement period modification, and sending to the user equipment a message indicating the neighbouring and / or serving cell measurement period modification as a response to the request fulfilling at least one condition.

[0012] According to a seventh aspect of the present disclosure, there is provided a non- transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least determine an energy state of the apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and request from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

[0013] According to an eighth aspect of the present disclosure, there is provided a non- transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least send to a user equipment at least two energy thresholds which define at least a low energy state, an intermediate energy state and a high energy state, receive from a user equipment a request for a neighbouring and / or serving cell measurement period modification, and send to the user equipment a message indicating the neighbouring and / or serving cell measurement period modification as a response to the request fulfilling at least one condition.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] FIGURE 1 illustrates an example system in accordance with at least some embodiments of the present invention;

[0015] FIGURE 2 is an example flow graph in accordance with at least some embodiments of the present invention;

[0016] FIGURE 3 illustrates an example apparatus capable of supporting at least some embodiments of the present invention;

[0017] FIGURE 4 illustrates signalling in accordance with at least some embodiments of the present invention, and

[0018] FIGURE 5 is a flow graph of a method in accordance with at least some embodiments of the present invention.EMBODIMENTS

[0019] To conserve power in power-limited UEs, methods are described herein to reduce a rate, or frequency, of measurements of serving and neighbouring cell, or beam, strengths at the UE. Reducing the rate corresponds to increasing a time period between such measurements. In particular, the UE may classify itself into one of plural possible energy states, and request a measurement frequency modification from the network which the UE determines, based on at least the determined energy state. The network may authorize the requested measurement frequency modification, enabling the UE to measure the serving and / or neighbouring cell signal strengths less often, conserving power in the UE. The measurement frequency modification may thus comprise a measurement frequency reduction. More broadly, the measurement frequency modification may be seen as a measurement period modification.

[0020] FIGURE 1 illustrates an example system in accordance with at least some embodiments of the present invention. This system includes a base stations 130, 135 in communication with UEs, such as UE 110. A radio link connects base station 130 with UE 110, The radio link may be bidirectional, comprising an uplink, UL, to convey information from UE 110 toward base station 130 and a downlink, DL, to convey information from the base station 130 toward UE 110.

[0021] Base station 130 is further coupled communicatively with core network node 140, which may comprise, for example, a mobility management entity, MME, or access andmobility management function, AMF. The core network node 140 may be coupled with further core network nodes, and with a network 150, which may comprise the Internet or a corporate network, for example. The system may communicate with further networks via network 150. Examples of the further core network nodes, which are not illustrated in FIGURE 1 for the sake of clarity, include gateways and subscriber information repositories.

[0022] Base station 130 has plural cells, or beams, 130A, 130B, of which UE 110 is in the situation illustrated in FIGURE 1 attached with cell or beam 130A, and base station 135 has plural cells or beams 135A, 135B. The number of cells or beams may be in excess of what is illustrated in FIGURE 1. It is also possible that a base station has a single cell or beam. A mobility event may comprise a switch from one beam to another beam of the same cell, or a switch from one cell to another cell. To support mobility procedures, UEs, including UE 110, are configured to conduct mobility measurements to measure signal strengths of adjacent beams and / or cells, and report results of these measurements to the network, which may then take a decision concerning a mobility event, such as a beam change or a cell switch.

[0023] Such mobility measurements at the UE side may be layer-3 measurements, and the corresponding reports may be layer-3, or L3, reports. Likewise a handover command from the network to a UE may be a layer-3 message. A cell switch or beam change directed using a layer-3 command involves a reset of layers lower than layer-3, which causes some delays. Layer 3 is in technology standardized by the 3rdgeneration partnership project, 3GPP, the radio resource control, RRC, layer. Of the lower layers layer- 1, or LI, is in 3GPP technology the physical layer, and layer-2, or L2, comprises the medium access control, MAC layer, radio link control, RLC, layer and packet data convergence protocol, PDCP, layer.

[0024] If mobility measurements, also known as radio resource management, RRM, measurements, indicate that a signal strength of a cell or beam the UE is currently attached with is declining and a signal strength of another cell or beam is increasing, then a switch to another cell or beam may be commanded by the network based on mobility measurement reports the UE has delivered to the network.

[0025] Performing RRM measurements consumes both time and energy in the UE. In certain cases, it may be desirable to perform these measurements less frequently to conserve energy. Reasons for this may include, for example, that the UE is immobile, that the UE is near a base station controlling the serving cell, and / or that the UE has low remaining battery power. The UE may be configured to reduce RRM measurement frequency, or increase a periodbetween RRM measurements, when certain conditions, or at least one condition, is or are fulfilled.

[0026] As one example, a low-mobility UE may reduce a frequency at which RRM measurements are conducted when a condition is satisfied. As an example of such a condition being satisfied, the inequality ( SrxlevRef - Srxlev ) < SsearchDeitaP may be satisfied. Here a Srxlev = Qrxlevemeas - qRxLevMin. Qrxlevemeas is received signal code power, RSCP, level measured by UE and qRxLevMin is a value specified in a system information block, SIB. SrxlevRef is a reference value of the serving cell, set as follows. After selecting or reselecting a new cell, or if (Srxlev- SrxlevRef)> 0, or if a relaxed RRM measurement ccriterion has not been met for time interval TsearchDeitaP, the UE shall set the value of SrxlevRef to the current Srxlev value of the serving cell.

[0027] Overall when mobility is low, the UE does not move about very much, wherefore cell or beam changes are expected to occur less frequently than in case the UE did move about more.

[0028] Another example, for a UE not near a cell edge, is that the condition comprises that both Srxlev < SsearchThreshoiap and Squal > SsearchThreshoidQ are satisfied. Squal = Qqualmeas - qQualMin. Qqualmeas is EcNo level measured by UE and qQualMin is a value specified in SIB. If SsearchThreshoidQ is not configured, the condition may comprise only the first inequality. The network may configure the triggering criteria independently that is, how to determine if a UE is either low-mobility or near the cell edge. If the UE is far away from the cell edge, then a mobility event is unlikely in the immediate future, this being particularly so if the UE has low mobility.

[0029] The following RRM measurement frequency or period modifications may be used for radio resource control, RRC, Idle and Inactive UEs where UE can stop measurements on neighbour cells for one or more hours:• El: Introduce additional SserchDeit P_st tion ry threshold to support 2-level speed evaluation (that is, stationary and low mobility states).• E2: Introduce additional TsearchDeitaP_stationary time to support 2-level speed evaluation (that is, stationary and low mobility).• E3: Take into account changes in beam measurements in the serving cell when evaluating the mobility status of UE, for example based on a number of beam changes, the beam can be the best beam or all beams exceeding a threshold.• E4: UE may determine its stationary property based on subscription information (for example based on universal subscriber identification module, USIM). For example, if the UE is a smart utility readout device, it will not move.• E5: Introduce an additional SsearchDeitaP_correction threshold and configure the UE to use it if only it detects that it observes higher received signal power variation that does not violate a stationary property, that is, rotating around itself, or dynamically changing multipath.• E6: UE may determine its confined mobility property based on subscription information (e.g. USIM). This kind of device is expected to move (slowly in many cases) or be stationary, but differently from Enhancement 5, above, these UEs are not expected to move out of a localized area during their lifetime.

[0030] On the other hand, the following RRM measurement frequency or period modification solutions may be used in RRC connected state:• SI: UE reports "stationary" status to network in a message, such as message Msg5, of a random access, RACH, process. How the mobility status is determined in this enhancement may be left up to UE implementation.• S2: Network provides (e.g. low mobility, not-at-cell-edge) evaluation parameters to UE via dedicated signalling.• S3: AMF sends a "stationary" indication concerning the UE to a base station, for example based on UE subscription.• S4: UE reports "stationary" in UE Assistance Information to network. How the mobility status is determined may be left to UE implementation in this enhancement.• S5: The network enables measurement relaxation based on UE's measurement report.

[0031] There are different types of UEs. While some UEs are highly capable smartphones, powered by large rechargeable batteries, other UEs have more modestcapabilities, roles and batteries. For example, Internet of Things, loT, nodes may be configured to read-out utility meters or provide simple electronic messages as a response to events, such as doors opening. Improved coverage, such as 30 metres indoor and up to 100 metres outdoor, and ultra-low power consumption is of interest in many applications. The use of ambient loT devices, that is, devices that are battery-less or devices that have batteries but don’t need battery replacement during the lifetime of the device, are of interest. Such devices are expected to have lower complexity, data rate, coverage, cost, and energy consumption than narrowband loT, NB-IoT. The use cases for ambient loT devices include identification, tracking, monitoring, sensing, logistics and supply chain management, transportation, manufacturing, including factory automation, healthcare, energy, agriculture, transportation, smart cities, environment, extreme conditions, and hazardous environments in some use cases where battery-powered devices are not feasible.

[0032] Design targets for ambient loT devices include improved link budget compared to existing radio frequency identification, RFID, solutions, frequency bands for global usability, ultra low cost, no need for battery charging or replacement (enabling low maintenance long life cycle operation), ultra low power (for example less than 100 microWatts, to enable operation with back-scattering or energy harvesting), small device size and form-factor, positioning accuracy (e.g., 3 - 5m), data rate e.g., 10 - 100 kbps, and support for mobile-originated and mobile-terminated data. Concerning energy sources, there are two options: firstly ambient devices may use of backscattering techniques to transmit, and secondly semi-ambient devices may operating with energy harvesting and / or with a small battery. The small battery may have a capacity of less than lOOmAh or less than 200mAh, for example.

[0033] By energy harvesting it is meant that the harvesting UE captures some energy from ambient electromagnetic radiation or other ambient energy. The ambient electromagnetic radiation used may be of radio-frequency, or light via photovoltaic cells, for example. Further examples of energy harvesting are energy obtained from the thermoelectric effect based on objects at different temperatures, and energy obtained from vibration, stress, strain or mechanical deformation using piezoelectric energy harvesting. By harvesting it is meant the harvested energy is stored in an energy storage of the UE and used in an action of the UE, such as transmission of radio signals or running a processor or microcontroller of the UE.

[0034] An ambient loT device may rely on backscattering to perform transmission, either with or without using energy stored in the device itself to amplify reflected signals.Alternatively, the ambient loT UE may have an independent signal generation capability and on-board energy storage. In the latter case, the loT UE has a transceiver and energy storage, such as a battery or capacitor, for example. A variant of the latter case is a device capable of network registration and both mobile-originated and mobile-terminated operations. A device of the latter case may consume power in the range of 1 milliWatt, mW, to 10 mW, for example.

[0035] In ambient loT devices, a further RRM measurement period modification trigger condition may be useful. This is because evaluation of the RRM measurement period modification conditions described herein above may not be useful for certain ambient loT cases due to dynamic changes in a stored energy level in the UE, which may furthermore be of an energy-harvesting type. Measurement period modification is used here as an example terminology, in some embodiments a measurement frequency modification might be stated instead.

[0036] For example, in a low energy case, RRM measurement period modification could be applied by using energy-related measurement relaxation conditions. In the low-energy case, RRM measurements may be relaxed to save energy even if other measurement period modification conditions are not fulfilled. However, this could lead to radio link failures, RLFs, which could be the case even when the other RRM measurement period modification criteria are evaluated, in other words, an energy level in the UE may be so low that the device cannot perform successful operations. Thus RLFs will happen regardless of whether any conditions are employed or not as energy available is simply not sufficient. A technical challenge thus presents itself in terms of how to overcome such a situation by adapting RRM measurement period modification criteria typical to energy harvesting devices.

[0037] In a high energy case, where the UE has a lot of energy available for use, adaptation of the RRM measurement period may not be needed for reasons related to energy as the UE default mode of operation without RRM measurement relaxation is feasible. Adaptation of the period might still be performed for other reasons, such as immobility of the UE, for example.

[0038] In a moderate energy case, where a quantity of energy stored in and / or available to the UE lies between the low-energy and the high-energy cases, RRM measurement period modification may be applied when needed, for example by evaluating the RRM measurement period modification criteria such as those described above, and / or at least one additional RRM measurement period modification condition for energy harvesting UEs.

[0039] Additional RRM measurement relaxation criteria for energy harvesting, EH, devices may be provided, such that the EH devices could either fully skip other RRM measurement period modification condition evaluation in case these EH-specific criteria are satisfied, or alternatively the EH device may use the additional conditions together with the other RRM measurement period modification conditions to find a suitable RRM measurement relaxation time, by which it is meant a time during which RRM measurements are skipped to conserve energy.

[0040] In a first embodiment, the UE is enabled to select / determine an energy state of the UE, based on at least two energy thresholds, the energy state being selected / determined from among at least a low energy state, an intermediate energy state and a high energy state. The energy state indicates a quantity of energy stored in, and / or otherwise available to, the UE. Further, the UE requests from a network a neighbouring and / or serving cell measurement period modification selected / determined by the UE based on the selected / determined energy state, and applies the neighbouring and / or serving cell measurement period modification in the UE as a response to a message received in the UE from the network indicating that the network accepts the request. Selecting the energy state may alternatively be referred to as determining the energy state.

[0041] In some embodiments, two energy thresholds Ethi and Eth2 are used to support multi-level energy evaluation at an EH UE to adopt RRM measurement relaxation decision based on the UE’s energy state, for example: a low energy state, where Ecurrent < Ethi and both serving and neighbouring cell measurement relaxation is recommended. In an intermediate energy state Ethi <ECUrrent < Eth2, where Eti<Et2. There is a trade-off of determination of RRM measurement period modification decision especially for intermediate energy cases. Short-term and long-term energy harvesting metrics may be checked to determine EH behavior and decide on a suitable RRM measurement period modification. By short-term it may be meant, for example, a one-minute or three-minute time period. By long-term it may be meant, for example, a five-minute or ten-minute time period or any multiple of short-term periods. For example, if a long-term energy harvesting pattern shows a stable or increasing energy harvesting yield, a relatively smaller RRM measurement period modification may be used than where the long-term energy harvesting pattern shows a decreasing energy harvesting yield. If a short-term energy harvesting rate is increasing but the long-term energy harvesting pattern shows a decreasing yield , then applying RRM measurement relaxation may be postponed until the short-term energy harvesting rate decreases. Finally in a high energy state Ecurrent > Eth2,serving and neighbour cell measurement relaxation due to energy-related reasons may be not necessary since the measurements can be carried out normally with the energy available. Thus the UE may be configured to, when in the high energy state, not request a modification of the neighbour cell measurement period due to energy-related reasons. The RRM measurement period may still be reduced for other reasons, such as UE immobility, for example.

[0042] When functioning according to the first embodiment, the EH UE sends assistance information about the RRM measurement period modification selection to a base station of the serving cell, wherein the assistance information may be an indication within an RRM relaxation request message, and / or as part of an RLF report that is sent by the UE to let the network know that this particular RLF happened during relaxed RRM measurements, and which energy state the UE was in when the RLF occurred. For example, the assistance information may be used by the network to improve parameters, such as thresholds and / or timers. Furthermore, these enhanced RLF reports may be used to re-train one or more machine learning algorithm for the determination of energy thresholds and RRM measurement relaxation decisions, if a machinelearning based solution is employed.

[0043] In a second embodiment, the number of energy state changes within a predefined time, Tstate_switching, is taken into account when evaluating the RRM measurement relaxation choice for an EH device in the intermediate energy state. These energy state changes may be changes between the energy states mentioned above: the low-energy state, the intermediate energy state and the high energy state.

[0044] In a third embodiment, a harvested energy arrival rate variation for short-term and long-term are estimated to determine the priority and urgency for RRM measurement period modification. By energy harvesting it is meant, that the harvesting UE captures some energy from ambient electromagnetic radiation or other ambient energy. The ambient electromagnetic radiation used may be of radio-frequency, or light via photovoltaic cells, for example. Further examples of energy harvesting are energy obtained from the thermoelectric effect based on objects at different temperatures, and energy obtained from vibration, stress, strain or mechanical deformation using piezoelectric energy harvesting. By harvesting it is meant the harvested energy is stored in an energy storage of the UE and used in an action of the UE, such as transmission of radio signals or running a processor or microcontroller of the UE.

[0045] The RRM measurement period modification for EH devices may be done using the first, the second or the third embodiment or a combination of any two, or indeed all three embodiments. Yet further, any of these alternatives may be combined with RRM relaxation conditions El - E6 and / or SI - S5, described herein above.

[0046] The energy thresholds for the RRM measurement period modification decision are applicable in one or more of the following RRC states: IDLE or INACTIVE or CONNECTED. In case an EH UE is not able to evaluate its energy arrival or energy storage for a number of times, such as one, two, or a configurable number of times, the UE may be configured to follow conditions El - E6 and / or SI - S5, only.

[0047] FIGURE 2 is an example flow graph in accordance with at least some embodiments of the present invention. The process may be performed in a UE configured to harvest energy from ambient electromagnetic radiation and / or from temperature differences, for example. By harvesting it is meant the harvested energy is stored in an energy storage of the UE and used in an action of the UE, such as transmission of radio signals or running a processor or microcontroller of the UE.

[0048] In phase 210, the UE determines, using at least two energy thresholds, an energy state of the UE from among at least three options, such as low energy, intermediate energy or high energy. The energy state may be selected based on a quantity of energy stored in a battery or other energy store of the UE, and / or a rate at which the UE harvests ambient energy. In case the energy level at the UE is below a lower threshold from among the at least two energy thresholds, the determination of 210 is the low energy state 220. When in the low energy state 220, the UE selects a neighbouring and / or serving cell measurement period modification 250 wherein a measurement period of neighbouring and / or serving cell measurement is increased. It may be increased from a default frequency, or from a current frequency, for example.

[0049] In case the energy level at the UE is over the lower threshold but below a higher threshold from among the at least two energy thresholds, the determination of phase 210 is the intermediate energy state 230. When in the intermediate energy state 230, the UE selects a neighbouring and / or serving cell measurement period modification 260 based in part on a rate at which the apparatus harvests energy, a rate of change of the rate at which the apparatus harvests energy, and / or a frequency of energy state changes. For example, if the energy harvesting rate is fast, in other words above a threshold, modifying the neighbouring cell measurement period may be unnecessary. If the energy harvesting rate is slow, themeasurement period may be increased. However if the rate of energy harvesting is in decline, even if the rate is on a high level, neighbouring and / or serving cell measurement period increase may be appropriate. Further, if the rate of change in energy state is high, then increasing the neighbouring cell measurement period is useful, since the risk of falling into the low energy state, and ensuing RLF, is elevated.

[0050] In case the energy level at the UE is over the higher threshold from among the at least two energy thresholds, the selection / determination of 210 is the high energy state 240. When in the high energy state 240, the UE may not need a neighbouring and / or serving cell measurement period modification for energy related reasons, and the modification 270 is a nil modification.

[0051] Once the neighbouring and / or serving cell measurement period modification 250, 260, 270, is selected, the process advances to phase 280, where the UE requests from the network to take the selected neighbouring and / or serving cell measurement period modification into use. If the network allows the modification, the UE will begin applying it. In some embodiments, the UE may begin applying the modification without permission from the network. In these embodiments, the UE may indicate the modification to the network only in RLF logs sent in case RLF takes place when the modification is in use.

[0052] In some embodiments, the UE is configured to determine the energy state and indicate the determined energy state to the network. The network is then enabled to determine a neighbouring and / or serving cell measurement period modification for the UE, and instruct the UE to take this modification into use. In such a case, the UE may be considered to request from the network a neighbouring and / or serving cell measurement period modification based on the determined energy state. In this case the UE requests the modification without specifying in the request, what the modification is.

[0053] FIGURE 3 illustrates an example apparatus capable of supporting at least some embodiments of the present invention. Illustrated is device 300, which may comprise, for example, a mobile communication device such as UE 110 of FIGURE 1. In applicable parts, device 300 may also correspond to a base station, such as one controlling the serving cell, for example. Comprised in device 300 is processor 310, which may comprise, for example, a single- or multi-core processor wherein a single-core processor comprises one processing core and a multi-core processor comprises more than one processing core. Processor 310 may comprise, in general, a control device. Processor 310 may comprise more than one processor.When processor 310 comprises more than one processor, device 300 may be a distributed device wherein processing of tasks takes place in more than one physical unit. Processor 310 may be a control device. A processing core may comprise, for example, a Cortex-A8 processing core manufactured by ARM Holdings or a Zen processing core designed by Advanced Micro Devices Corporation. A processing core or processor may be, or may comprise, at least one qubit. Processor 310 may comprise at least one Qualcomm Snapdragon and / or Intel Atom processor. Processor 310 may comprise at least one application- specific integrated circuit, ASIC. Processor 310 may comprise at least one field-programmable gate array, FPGA. Processor 310, optionally together with memory and computer instructions, may be means for performing method steps in device 300, such as selecting, requesting, determining, sending, receiving and applying. Processor 310 may be configured, at least in part by computer instructions, to perform actions.

[0054] A processor may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analogue and / or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analogue and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as UE or base station, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0055] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0056] Device 300 may comprise memory 320. Memory 320 may comprise randomaccess memory and / or permanent memory. Memory 320 may comprise at least one RAM chip. Memory 320 may be a computer readable medium. Memory 320 may comprise solid-state, magnetic, optical and / or holographic memory, for example. Memory 320 may be at least in part accessible to processor 310. Memory 320 may be at least in part comprised in processor 310. Memory 320 may be means for storing information. Memory 320 may comprise computer instructions that processor 310 is configured to execute. When computer instructions configured to cause processor 310 to perform certain actions are stored in memory 320, and device 300 overall is configured to run under the direction of processor 310 using computer instructions from memory 320, processor 310 and / or its at least one processing core may be considered to be configured to perform said certain actions. Memory 320 may be at least in part external to device 300 but accessible to device 300. Memory 320 may be transitory or non- transitory. The term “non-transitory”, as used herein, is a limitation of the medium itself (that is, tangible, not a signal) as opposed to a limitation on data storage persistency (for example, RAM vs. ROM).

[0057] Device 300 may comprise a transmitter 330. Device 300 may comprise a receiver 340. Transmitter 330 and receiver 340 may be configured to transmit and receive, respectively, information in accordance with at least one cellular or non-cellular standard. Transmitter 330 may comprise more than one transmitter. Receiver 340 may comprise more than one receiver. Transmitter 330 and / or receiver 340 may be configured to operate in accordance with global system for mobile communication, GSM, wideband code division multiple access, WCDMA, 5G, long term evolution, LTE, IS-95, wireless local area network, WLAN, Ethernet and / or worldwide interoperability for microwave access, WiMAX, standards, for example.

[0058] Device 300 may comprise a near-field communication, NFC, transceiver 350. NFC transceiver 350 may support at least one NFC technology, such as NFC, Bluetooth, Wibree or similar technologies.

[0059] Device 300 may comprise user interface, UI, 360. UI 360 may comprise at least one of a display, a keyboard, a touchscreen, a vibrator arranged to signal to a user by causing device 300 to vibrate, a speaker or a microphone. A user may be able to operate device 300 via UI 360, for example to configure loT device parameters.

[0060] Device 300 may comprise or be arranged to accept a user identity module 370. User identity module 370 may comprise, for example, a subscriber identity module, SIM, cardinstallable in device 300. A user identity module 370 may comprise information identifying a subscription of a user of device 300. A user identity module 370 may comprise cryptographic information usable to verify the identity of a user of device 300 and / or to facilitate encryption of communicated information and billing of the user of device 300 for communication effected via device 300.

[0061] Processor 310 may be furnished with a transmitter arranged to output information from processor 310, via electrical leads internal to device 300, to other devices comprised in device 300. Such a transmitter may comprise a serial bus transmitter arranged to, for example, output information via at least one electrical lead to memory 320 for storage therein. Alternatively to a serial bus, the transmitter may comprise a parallel bus transmitter. Likewise processor 310 may comprise a receiver arranged to receive information in processor 310, via electrical leads internal to device 300, from other devices comprised in device 300. Such a receiver may comprise a serial bus receiver arranged to, for example, receive information via at least one electrical lead from receiver 340 for processing in processor 310. Alternatively to a serial bus, the receiver may comprise a parallel bus receiver.

[0062] Device 300 may comprise further devices not illustrated in FIGURE 3. For example, where device 300 comprises a smartphone, it may comprise at least one digital camera. Some devices 300 may comprise a back-facing camera and a front-facing camera, wherein the back-facing camera may be intended for digital photography and the front-facing camera for video telephony. Device 300 may comprise a fingerprint sensor arranged to authenticate, at least in part, a user of device 300. In some embodiments, device 300 lacks at least one device described above. For example, some devices 300 may lack a NFC transceiver 350 and / or user identity module 370.

[0063] Processor 310, memory 320, transmitter 330, receiver 340, NFC transceiver 350, UI 360 and / or user identity module 370 may be interconnected by electrical leads internal to device 300 in a multitude of different ways. For example, each of the aforementioned devices may be separately connected to a master bus internal to device 300, to allow for the devices to exchange information. However, as the skilled person will appreciate, this is only one example and depending on the embodiment various ways of interconnecting at least two of the aforementioned devices may be selected without departing from the scope of the present invention.

[0064] FIGURE 4 illustrates signalling in accordance with at least some embodiments of the present invention. On the vertical axes are disposed, on the left, a UE of FIGURE 1 , and on the right, a base station BS, which controls a serving cell of the UE. Time advances from the top toward the bottom.

[0065] In phase 410, the base station provides to the UE at least one criterion for RRM measurement period modification. These may be the at least two energy thresholds mentioned above, for example, in the case of the first, second and third embodiments. For the second embodiment, the criteria provided may include one or more parameters associated with energy computation / evaluation, for example, energy state switching timer T, threshold N 1 , averaging window size M, and averaging factors (Fl, F2), which will be used to implement a EH UE- specific RRM measurement period modification criterion. For the third embodiment, the criteria provided in this phase may include one or more parameters associated with energy computation / evaluation, for example, time T1 for long-term average energy computation, delta T1 for short-term average energy computation, and optionally at least one priority criterion. In an example embodiment, the threshold N1 may be an energy state switching threshold. An energy value comprising a weighted combination of the average energy of the last M energy states and the current energy state may be determined as Eavg= Fl *+ F2 * Ecurrent. Here Emis the energy harvested during the mth harvesting interval, and Fl and F2 are weighting factors, such that Fl + F2 = 1.

[0066] In phase 420, the UE performs an energy condition check using the at least two energy thresholds. Phase 420 thus corresponds to phase 210 of FIGURE 2. In dependence of a result of phase 420, process 401, process 402 or a third process, not illustrated in FIGURE 4, will be performed. Process 401, corresponding to the low-energy state, is described first.

[0067] Initially in process 401 , in phase 430, the UE determines for itself the low-energy state. Further in phase 430, the UE selects RRM measurement modification, namely an increase in the period at which the UE performs RRM measurements of the serving and neighbouring cells, in response to finding itself in the low-energy state. In phase 440, the UE requests from the base station the measurement period modification it selected in phase 430, and in phase 450 the base station indicates that this modification may be applied in the UE. Responsively, in phase 460 the UE takes this modification into use and increases its period between RRM measurements. Subsequently, in phase 470, the UE provides an RLF log to the base station, or another base station, informing the base station of an RLF. The RLF log comprises anindication of the RRM measurement modification in use in the UE when the RLF took place. In some embodiments, the UE does not transmit message 440 or receive message 450, rather, the UE takes the modification into use autonomously, and indicates the modification to the network only in RLF logs in case RLF takes place during the modification. In some variants of these embodiments, the UE is configured to indicate the modification to the network without regard to the presence of RLF. In embodiments where the base station decides whether the modification may be applied in the UE, the UE will not take the modification into use if the base station does not allow it in phase 450. Likewise in embodiments where the base station decides whether the modification may be applied in the UE, the UE may be further configured to indicate to the base station that it has taken the modification into use.

[0068] In phase 480, the network, for example the base station which received the RLF log but alternatively another network node, improves configured parameters, such as thresholds, timers, and other parameters transmitted in phase 410, based on the RLF log 470. The RLF logs may be used to re-train a machine-learning, ML, algorithm for RRM measurement relaxation decisions in case an ML based solution is used. This concludes process 401.

[0069] Initially in process 402, in phase 490, the UE determines for itself the intermediate energy state. In phase 4100, a synchronization signal block, SSB, is sent from the base station and phase 4110 represents a measurement of the SSB at the UE side. As part of phase 4110, in some embodiments the UE evaluates at least one of conditions El - E6 or SI - S5, described herein above. In phase 4120, the UE performs the second embodiment and / or the third embodiment described herein above, in other words, it considers whether a number of energy state switched between the low, intermediate and high energy state exceeds a threshold within a set time period, and / or determines information concerning the rate of energy harvesting at the UE, to decide whether to perform RRM measurement period modification.

[0070] In phase 4130, the UE informs the base station of the selection of the RRM measurement period modification, and, optionally, also that the intermediate energy state was selected. In phase 4140, the base station allows the RRM measurement period modification, which the UE then responsively applies in the UE, in phase 4150. Phase 4160 is a transmission of an RLF log and phase 4170 is a use of the RLF log in the network. Phases 4160 and 4170 correspond to phases 470 and 480, except as to the information provided to the base station, namely in phase 4160 the UE informs the base station that the intermediate energy state was inforce in the UE, and the RRM measurement period modification indicated in phase 4160 may be different from that indicated in phase 470. Naturally, in case no RLF takes place, no RLF log (phases 470 and 4160) is sent to the network. This concludes process 402.

[0071] If in phase 420 the UE selects the high energy state, then a third process is performed, distinct from process 401 and process 402. In this third process, the UE measures SSB transmitted by the base station, without applying RRM measurement period modification. As no modification is selected, the base station is not informed of any modification, and also any RLF logs sent need not comprise information on any RRM measurement period modification.

[0072] The RRM measurement period modifications described herein provide distinct advantages and technical effects. In particular, the energy consumption of EH UEs is reduced when they are in high need of energy. Quality of service, QoS, of EH devices is enhanced when their energy arrival or energy storage is high. The base station is enabled to use the assistance information sent in the RRM measurement relaxation decision and / or the RLF log by the UE. The enhanced RLF logs may be used to improve configured parameters and to re-train RRM measurement relaxation decisions on the network side.

[0073] Radio link failures and handover failures may be reduced due to low energy availability at the EH UE side, which impacts UE data throughput. For this energy condition and the number of energy state, switching criteria may be configured properly to avoid radio link and handover failures.

[0074] FIGURE 5 is a flow graph of a method in accordance with at least some embodiments of the present invention. The phases of the illustrated method may be performed in UE 110, or in a control device configured to control the functioning thereof, when installed therein. The UE may be an energy harvesting UE.

[0075] Phase 510 comprises determining an energy state of an apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state. Phase 520 comprises requesting from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

[0076] It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts.It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting.

[0077] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Where reference is made to a numerical value using a term such as, for example, about or substantially, the exact numerical value is also disclosed.

[0078] As used herein, a plurality of items, structural elements, compositional elements, and / or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

[0079] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the preceding description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well- known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

[0080] While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, exceptas by the claims set forth below.

[0081] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", that is, a singular form, throughout this document does not exclude a plurality.

[0082] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.INDUSTRIAL APPLICABILITY

[0083] At least some embodiments of the present invention find industrial application in cellular communication.ACRONYMS LIST3GPP 3rdgeneration partnership projectEH energy harvestingRRM radio resource measurementSSB synchronization signal blockUE user equipmentREFERENCE SIGNS LIST

Claims

CLAIMS:

1. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to: determine an energy state of the apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and request from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

2. The apparatus according to claim 1, further configured to apply the neighbouring and / or serving cell measurement period modification in the apparatus as a response to a message received from the network.

3. The apparatus according to claim 2, configured to perform the applying of the neighbouring and / or serving cell measurement period modification, as the response to the message, in dependence of the determined energy state of the apparatus.

4. The apparatus according to any of claims 1 - 2, configured to select, based on the determined energy state, the neighbouring and / or serving cell measurement period modification before requesting the neighbouring and / or serving cell measurement period modification from the network.

5. The apparatus according to any of claims 1 - 4, further configured to receive the at least two energy thresholds from the network.

6. The apparatus according to any of claims 1 - 5, configured to indicate the determined energy state to the network when requesting the neighbouring and / or serving cell measurement period modification.

7. The apparatus according to any of claims 1 - 6, wherein the apparatus is configured to select the neighbouring and / or serving cell measurement period modification as an increasedmeasurement period of neighbouring and / or serving cell measurement when the determined energy state is the low energy state.

8. The apparatus according to any of claims 1 - 7, wherein the apparatus is configured to select the neighbouring and / or serving cell measurement period modification based in part on a rate at which the apparatus harvests energy when the determined energy state is the intermediate energy state.

9. The apparatus according to claim 8, wherein the apparatus is configured to select the neighbouring and / or serving cell measurement period modification based in part on a rate of change of the rate at which the apparatus harvests energy when the determined energy state is the intermediate energy state.

10. The apparatus according to any of claims 1 - 9, wherein the apparatus is configured to select the neighbouring and / or serving cell measurement period modification based in part on a frequency of changes in the determined energy state when the determined energy state is the intermediate energy state.

11. An apparatus comprising at least one processing core and at least one memory storing instructions that, when executed by the at least one processing core, cause the apparatus at least to: send to a user equipment at least two energy thresholds which define at least a low energy state, an intermediate energy state and a high energy state; receive from a user equipment a request for a neighbouring and / or serving cell measurement period modification, and send to the user equipment a message indicating the neighbouring and / or serving cell measurement period modification as a response to the request fulfilling at least one condition.

12. The apparatus according to claim 11, wherein the apparatus is configured to abstain from sending the message to the user equipment as a response to the request not fulfilling the at least one condition.

13. The apparatus according to claim 11 or 12, further configured to receive, from the user equipment or a second user equipment, a radio link failure report, and to modify at least one network parameter based on the radio link failure report and a specific neighbouring and / or serving cell measurement period modification the user equipment or the second user equipment was using when the radio link failure described by the radio link failure report occurred.

14. A method, comprising: determining an energy state of an apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and requesting from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

15. The method according to claim 14, further comprising applying the neighbouring and / or serving cell measurement period modification in the apparatus as a response to a message received from the network.

16. The method according to claim 15, comprising performing the applying of the neighbouring and / or serving cell measurement period modification, as the response to the message, in dependence of the determined energy state of the apparatus.

17. The method according to any of claims 14 - 15, comprising selecting, based on the determined energy state, the neighbouring and / or serving cell measurement period modification before requesting the neighbouring and / or serving cell measurement period modification from the network.

18. The method according to any of claims 14 - 17, further comprising receiving the at least two energy thresholds from the network.

19. The method according to any of claims 14 - 18, comprising indicating the determined energy state to the network when requesting the neighbouring and / or serving cell measurement period modification.

20. The method according to any of claims 14 - 19, wherein the method comprises selecting the neighbouring and / or serving cell measurement period modification as an increasedmeasurement period of neighbouring and / or serving cell measurement when the determined energy state is the low energy state.

21. The method according to any of claims 14 - 20, wherein the method comprises selecting the neighbouring and / or serving cell measurement period modification based in part on a rate at which the apparatus harvests energy when the determined energy state is the intermediate energy state.

22. The method according to claim 21, wherein the method comprises selecting the neighbouring and / or serving cell measurement period modification based in part on a rate of change of the rate at which the apparatus harvests energy when the determined energy state is the intermediate energy state.

23. The method according to any of claims 14 - 22, wherein the method comprises selecting the neighbouring and / or serving cell measurement period modification based in part on a frequency of changes in the determined energy state when the determined energy state is the intermediate energy state.

24. A method comprising: sending to a user equipment at least two energy thresholds which define at least a low energy state, an intermediate energy state and a high energy state; receiving from a user equipment a request for a neighbouring and / or serving cell measurement period modification, and sending to the user equipment a message indicating the neighbouring and / or serving cell measurement period modification as a response to the request fulfilling at least one condition.

25. The method according to claim 24, wherein the method comprises abstaining from sending the message to the user equipment as a response to the request not fulfilling the at least one condition.

26. The method according to claim 24 or 25, further comprising receiving, from the user equipment or a second user equipment, a radio link failure report, and to modify at least one network parameter based on the radio link failure report and a specific neighbouring and / orserving cell measurement period modification the user equipment or the second user equipment was using when the radio link failure described by the radio link failure report occurred.

27. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least: determine an energy state of the apparatus, based on at least two energy thresholds, from among at least a low energy state, an intermediate energy state and a high energy state, and request from a network a neighbouring and / or serving cell measurement period modification based on the determined energy state.

28. A non-transitory computer readable medium having stored thereon a set of computer readable instructions that, when executed by at least one processor, cause an apparatus to at least: send to a user equipment at least two energy thresholds which define at least a low energy state, an intermediate energy state and a high energy state; receive from a user equipment a request for a neighbouring and / or serving cell measurement period modification, and send to the user equipment a message indicating the neighbouring and / or serving cell measurement period modification as a response to the request fulfilling at least one condition.

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