Method for providing an energy information of a wireless device in a communication network

Abstract

A method for providing an energy information of a wireless device (14a, 14b, 14c; 14), preferably an ambient Internet of Things (IoT) device, in a communication network (10), the method comprising: - Determining, by the wireless device (14a, 14b, 14c; 14), whether a condition for transmitting a message comprising an energy information of the wireless device (14a, 14b, 14c; 14) is fulfilled; and - Transmitting, by the wireless device (14a, 14b, 14c; 14), the message based on a result of the determining to a node (12) of the communication network (10).

Description

[0001] R. 416157

[0002] - 1 -

[0003] Specification

[0004] Title

[0005] Method for providing an energy information of a wireless device in a communication network

[0006] The invention concerns a method for providing an energy information of a wireless device, preferably an ambient Internet of Things (loT) device, in a communication network. Further, the invention concerns a wireless device, preferably an ambient loT device, a computer program and a non-transitory computer readable medium.

[0007] Background

[0008] The state of the art in ambient loT devices, as currently studied by 3GPP, encompasses low-complexity, low-energy demanding wireless devices designed for various use-cases, such as inventory management, localization, and sensor data exchange within indoor and outdoor environments. These wireless devices are categorized into three main groups, each with different power consumption and transmission characteristics.

[0009] Type 1 devices have a peak power consumption of approximately 1 pW, comprise an energy storage, and have an initial sampling frequency offset (SFO) of up to 10X ppm. They do not have amplification in the device for either downlink (DL) or uplink (UL) transmission, and their UL transmission is based on backscattering an externally provided carrier wave.

[0010] Type 2a and Type 2b devices have peak power consumption of a few hundred pW, comprise an energy storage, and have an initial SFO of up to 10X ppm. Both types have amplification for DL and / or UL transmission, with Type 2a devices generating UL transmissions by backscattering externally provided carrier waves and Type 2b devices generating UL transmission internally. R. 416157

[0011] - 2 -

[0012] The ambient loT device may be configured to directly and bidirectionally communicate with a user equipment or a base station. The ambient loT device may also be configured to indirectly and bidirectionally communicate with a base station via at least one intermediate node, e.g., a user equipment (UE) or a reader or a relay.

[0013] The ambient loT device may also be configured for receiving downlink transmissions directly from a base station, and for receiving uplinks transmissions to the base station via at least one assisting node. The ambient loT device may alternatively be configured for receiving downlink transmission from the base stations via at least one assisting node, and for transmitting uplinks transmissions directly to the base station.

[0014] When an ambient loT device is triggered by the network or a reader to initiate a random access procedure, a current energy level of the device may not be sufficient for transmitting a first message of the random access procedure or at least not for subsequent transmissions, e.g., payload transmissions of buffered messages. Therefore, triggering an ambient loT device with such an energy level may not be efficient.

[0015] Disclosure of the invention

[0016] According to a first aspect, there is provided a method for providing an energy information of a wireless device, preferably an ambient Internet of Things (loT) device, in a communication network.

[0017] The method according to the first aspect comprises:

[0018] Determining, by the wireless device, whether a condition for transmitting a message comprising an energy information of the wireless device is fulfilled; and

[0019] Transmitting, by the wireless device, the message based on a result of the determining to a node of the communication network.

[0020] The method according to the first aspect can be understood as a method for wireless communications, specifically of operating the wireless device, preferably the ambient loT device, of the communication network. R. 416157

[0021] - 3 -

[0022] According to a second aspect, there is provided a wireless device, preferably an ambient loT device, of a communication network. The wireless device is configured to execute the method according to the first aspect, or its embodiments.

[0023] According to a third aspect, there is provided a computer program comprising machine-readable instructions to cause the wireless device as defined by the second aspect to execute the method according the first aspect, and / or its embodiments.

[0024] According to a fourth aspect, there is provided a non-transitory computer readable medium having stored thereon the computer program as defined by the third aspect.

[0025] The communication network may comprise a wireless network and a core network. The communication network may be configured as a cellular network, preferably according to 3GPP specifications, e.g., according to 3GPP release 18 or beyond, or as a wireless Local Area Network (LAN), preferably according to IEEE specifications. The communication network comprises at least the wireless device and the node.

[0026] The wireless device may be configured as a low-energy or low-power device. The wireless device may have a peak power consumption of less than 1 mW, preferably less than 500 pW, specifically less than 100 pW, according to an embodiment, less than 10 pW, e.g., approximately 1 pW.

[0027] The wireless device is preferably configured for energy harvesting, thus exploiting ambient energy sources, e.g., radio waves, thermal radiation, mechanical vibrations etc. as power supply. The wireless device may or may not comprise an energy storage, e.g., a battery.

[0028] Specifically, the wireless device is different from a Reduced Capability (Redcap) device, a narrow band loT (NB-loT) device, a device for enhanced machine-type communication (eMTC), e.g., due to its lower hardware complexity and / or lower costs, and / or smaller form factors. Additionally, a communication between the R. 416157

[0029] - 4 - wireless device and the node may not be controlled by a Radio Resource Control (RRC) layer. Particularly, a Hybrid Automated Repeat Request (HARQ) procedure may not be deployed or deployable for the communication between the wireless device and the node.

[0030] The wireless device may be arranged on or part of an environmental sensor, e.g., deployed in smart buildings, industrial facilities, and urban infrastructure to enable environmental monitoring and control, a smart home device to enable remote monitoring and control of home environments for energy efficiency, security, and convenience, a wearable health and / or fitness tracker to enable personal health and fitness tracking, as well as remote patient monitoring in healthcare applications, an asset tracking device to enable monitoring the location and status of assets, vehicles, and inventory in logistics, transportation, and supply chain management applications, an industrial loT sensor and / or actuator to enable monitoring and controlling machinery, equipment, and processes, a smart agriculture device to enable optimizing resource usage and improving crop yields, a smart city infrastructure unit to enable smart street lighting, traffic monitoring, waste management, public safety, and environmental monitoring.

[0031] The node of the communication network may be a radio or wireless node, or a core network node. The radio node may be a base station or a user equipment, e.g., configured as a reader for ambient loT devices, or a relay or an integrated access and backhaul (IAB).

[0032] The proposed solution enables specifically an ambient loT device to make independent decisions based on its energy status, ensuring that it can effectively communicate its energy information without requiring external intervention. By autonomously determining whether the condition for transmitting the energy information message is fulfilled, the wireless device can efficiently manage its energy resources. This self-regulating capability allows the device to transmit the R. 416157

[0033] - 5 - energy information message to the network node when necessary, thereby facilitating proactive energy management within the communication network. This is especially beneficial for low-power or low-energy wireless devices, such as ambient loT devices, where resources must be managed meticulously. Specifically for these ambient loT devices, the invention establishes a procedure to report their energy status to the reader or another node of the network.

[0034] According to an embodiment, the condition represents a relation between an energy level of the wireless device and a requirement on the energy level of the wireless device. The energy level may be a current or predicted energy level of the device. The energy level may be a relative or absolute fill level of an energy storage of the device. The requirement on the energy level may be an energy threshold for the, specifically current or predicted, energy level of the device. The condition requires that the energy level is smaller than or equal to or greater than the energy threshold. This allows the device for signaling of energy depletion and safeguarding its operational capabilities for future communication activities.

[0035] According to an embodiment, the requirement is based on a minimum energy level necessary for a transmission of the wireless device. Here, the requirement may require that the energy level is smaller than or equal to or greater than a minimum energy level necessary for at least one, preferably a defined number, of transmission(s) of the wireless device. The requirement may also require that the energy level is sufficient for the transmission of all or a defined subset of messages contained in a buffer of the wireless device. The requirement may further require that after the transmission(s) at least a defined energy level is maintained. The message may be transmitted in case the requirement is fulfilled or, preferably, in case the requirement is not fulfilled. This ensures that the network is informed about devices with low energy levels, enabling the respective devices to fulfill their communication tasks without risking energy depletion.

[0036] According to an embodiment, the message is transmitted periodically by the wireless device, and a periodicity of the transmission is pre-configured or configured by the node or a further node of the communication network.

[0037] The further node may be a radio node, e.g., an intermediate or assisting device such as a relay or a UE, or a core network node of the communication network. A R. 416157

[0038] - 6 - configuration information provided to the wireless device may comprise instructions for the device regarding a timing and / or the periodicity of the periodic transmissions.

[0039] By transmitting the message comprising the energy information at regular intervals, the network can maintain up-to-date information about the device's energy resources. This enables the network to adapt its operations based on the real-time energy status of the devices, leading to more efficient energy management and improved overall network performance.

[0040] According to an embodiment, the method further comprises:

[0041] Receiving, by the wireless device, a trigger message from the node or a further node of the communication network, wherein the step of determining is carried out in response to receiving the trigger message.

[0042] Here, the trigger message may comprise a configuration of the periodicity of the transmission of the message comprising the energy information. The trigger message may be part of a paging message transmitted during a paging occasion. The further node may be a radio node, e.g., an intermediate or assisting device such as a relay or a UE, or a core network node of the communication network.

[0043] In other words, the wireless device may be instructed by the node or the further node to report its energy information or status. To this end, a control message or a trigger message may be transmitted to the wireless device. For example, a paging message may include a trigger information or a configuration to instruct the wireless device to report its energy information or status. Additionally or alternatively, the condition may also depend on a use case of the wireless device and / or may be defined by higher layers, e.g., by an application layer. This allows for requesting energy information from dedicated wireless devices in the network, thus enhancing efficiency of resource utilization.

[0044] According to an embodiment, the step of determining is carried out prior and / or during and / or after a random access procedure of the wireless device, and / or R. 416157

[0045] - 7 - in response to monitoring, by the wireless device, a paging occasion and / or receiving, by the wireless device, a paging message; and / or after transmission of payload data by the wireless device.

[0046] The random access procedure preferably comprises at least the transmission of a first message of the random access procedure from the wireless device to a node of the communication network and the transmission of a second message of the random access procedure from the node to the wireless device. The first message may comprise or consist of the random access preamble. The random access preamble may comprise a random number and / or a device identification information. The second message may comprise of consist of the random access response. The random access response may be an echo of the random number and / or the device identification information comprised by the random access preamble.

[0047] Messages of the random access procedure transmitted between the node and the wireless device, i.e., messages transmitted from the wireless device and received by the node and / or messages transmitted from the node and received by the wireless device, may either be transmitted directly, specifically, on the physical random access channel (PRACH), or indirectly via an intermediate or assisting node of the communication network. As an example, a message received by the wireless device may be transmitted from a core node of the communication network via a radio node, e.g., a base station, of the communication network, to the wireless device, and vice versa.

[0048] By considering the random access procedure, paging occasions, and payload data transmission, the method optimizes the timing of energy information transmissions, aligning them with the device's operational states and network signaling. This adaptability enhances the efficiency of energy management within the communication network, allowing for improved energy information dissemination.

[0049] According to an embodiment, the message is configured as an energy reporting message specifically for reporting the energy information, and / or R. 416157

[0050] - 8 - is a message of a random access procedure of the wireless device, particularly, of a first message and / or a third message of the random access procedure, and / or is a notification message for notifying the node that the wireless device is refraining from at least one future, specifically scheduled, transmission.

[0051] The notification message may consist of or comprise an indication that the wireless device is refraining from at least one future, specifically scheduled, transmission. To this end, a single bit may be utilized.

[0052] By tailoring the message format to serve as a dedicated energy reporting mechanism and / or integrating it into the random access procedure, the method optimizes the communication of energy-related data while minimizing additional signaling overhead. Furthermore, the notification capability allows for proactive energy management, enhancing the overall efficiency of energy utilization within the network.

[0053] According to an embodiment, the first message of the random access procedure comprises a random value and a defined number of bits representing the energy information. The random value is preferably used for requesting access to a transmission medium of the communication network, specifically for requesting transmission resources. The integration of the defined number of bits representing the energy information into the first message of the random access procedure allows the wireless device to convey its energy status as part of the initial communication exchange during the random access procedure, thus streamlining the communication between the wireless device and the corresponding node of the wireless communication network.

[0054] According to an embodiment, the energy information comprises at least one bit, preferably a bit sequence, representing a number and / or a size of data blocks and / or messages which may be transmitted by the wireless device based on an / the energy level of the wireless device, and / or a number of contention attempts and / or a number of failed attempts of the wireless device for accessing a transmission medium of the communication network by initiating the random access procedure, and / or whether (requested) payload data may be transmitted or not, and / or R. 416157

[0055] - 9 - a / the energy level of the wireless device.

[0056] The number and / or size of data blocks and / or messages that the wireless device may transmit based on its energy level indicates the device's capacity for data transmission and enables the network to adapt its resource allocation based on the device's energy reserves.

[0057] The number of contention attempts and / or failed attempts of the wireless device for accessing the transmission medium of the communication network through the random access procedure indicates the device's interaction with the network and its energy expenditure during access attempts.

[0058] Whether (requested) payload data may be transmitted or not indicates the device's ability to handle payload data transmission based on its energy status. The energy level of the wireless device provides a direct representation of the device's remaining energy reserves.

[0059] By conveying these details, the wireless device enables the network to make informed decisions regarding resource allocation and access prioritization.

[0060] According to an embodiment, the energy information further represents a capability of the wireless device for energy harvesting, and, optionally, which type(s) of energy harvesting the wireless device is capable of.

[0061] The capability may be a binary information (yes / no). The type of energy harvesting may be selected from a group comprising: solar, kinetic, thermal, or radiofrequency energy. By conveying its energy harvesting capability and the specific types of energy it can harness, the wireless device enables the network to optimize the allocation resources based on the device's energy harvesting potential, ensuring that energy-constrained devices can leverage available ambient energy sources to support their communication activities.

[0062] According to an embodiment, the method further comprises:

[0063] Refraining, by the wireless device, from transmitting the message based on a result of the determining,

[0064] Determining, by the wireless device, whether a condition for transmitting an unavailability message is fulfilled, R. 416157

[0065] - 10 -

[0066] Transmitting the unavailability message to the node based on a result of the determining, and

[0067] Optionally, changing an operational mode of the wireless device, preferably into an energy-saving or energy-harvesting mode.

[0068] By refraining from unnecessary or impossible or unfavorable transmissions of energy information, transmitting unavailability messages, and potentially transitioning into energy-saving or energy-harvesting modes, the device contributes to proactive energy management within the network. These actions enable the network to adapt its operations based on the device's energy constraints.

[0069] According to a further aspect of the invention, there is provided a (wireless) communication network comprising at least the wireless device and the node.

[0070] The non-transitory computer readable medium is preferably configured to store the computer program to be executed by a processor of the first LAN element and / or the second LAN element and / or the communication network. The non- transitory computer readable media may include RAM, ROM, EEPROM, and any other non-volatile storage device.

[0071] Description of the figures

[0072] Exemplary embodiments of the present invention are depicted in the figures, which are not to be construed as limiting the claims, and are explained in greater detail below.

[0073] Fig. 1 schematically illustrates a communication network according to an embodiment of the invention; and

[0074] Fig. 2 schematically illustrates a method according to an embodiment of the invention.

[0075] Fig. 1 schematically illustrates a communication network 10 according to an aspect of the invention. The communication network 10 is configured as a cellular communication network 10, preferably according to 3GPP specifications. The communication network 10 may comprise a core network and a wireless network. R. 416157

[0076] - 11 -

[0077] The communication network 10 comprises a radio node 12, configured as a user equipment 12, or a reader 12 for an ambient Internet of Things (loT) device, or a relay node acting as a reader, and a plurality of wireless devices 14a, 14b, 14c, preferably configured as ambient loT devices 14a, 14b, 14c, specifically according to 3GPP specifications. The wireless devices 14a, 14b, 14c are collectively represented by reference sign 14. The communication network 10 further comprises a radio node 16 configured as a base station 16.

[0078] For requesting access to a transmission medium of the communication network 10, the wireless devices 14 are configured to perform a method for initiating a preferably slot-based random access procedure. Here, the random access procedure may be based on a slotted ALOHA random access MAC protocol. I.e., the wireless devices 14 are configured to begin a transmission only at the beginning of a slot. The length of the slot preferably equals the sum of a packet transmission time and a maximum propagation delay in the network 10 to ensure that both transmission and reception of a data packet can be completed within one slot.

[0079] The random access procedure may be established between the respective wireless device 14a, 14b, 14c and the reader 12, or between the respective wireless device 14a, 14b, 14c and the base station 16. For the latter case, transmission between the wireless devices 14 and the base station 16 may be routed or relayed via the reader 12.

[0080] According to an alternative embodiment, the base station 16 may be configured as a reader for the wireless devices 14. Consequently, messages of the random access procedure are transmitted directly between the base station 16 and the wireless devices 14a, 14b, 14c (i.e., without routing them via the radio node 12).

[0081] The wireless devices 14 are configured for providing an energy information of the respective wireless device 14 by performing the method according to the first aspect of the invention, and / or its embodiments, as further described in Fig. 2.

[0082] The energy information may be provided prior to, during, or after the random access procedure. Here, the wireless device(s) 14 may be instructed or R. 416157

[0083] - 12 - configured by the reader 12, e.g., by using a second message of the random access procedure (access response message), to transmit its or their energy status. For such a (reporting) transmission, corresponding resources may be allocated by the reader node, preferably also using the second message.

[0084] Fig. 2 schematically illustrates a method 100 for providing an energy information of a wireless device 14a, preferably an ambient Internet of Things (loT) device 14a, in a communication network according to an embodiment of the invention.

[0085] The method 100 comprises an optional step 110 of receiving, by the wireless device 14a, a trigger message from a node or a further node of the communication network.

[0086] The method 100 comprises a step 120 of determining, by the wireless device 14a, preferably in response to receiving the trigger message, whether a condition for transmitting a message comprising an energy information of the wireless device 14a is fulfilled.

[0087] The method 100 comprises a step 130 of transmitting, by the wireless device 14a, the message based on a result of the determining to a node of the communication network. In other words, in step 130, based on the result of the determining, the message is either transmitted to the node or is not transmitted to the node.

[0088] Specifically, the method 100 may comprise optional steps of

[0089] Refraining, by the wireless device 14a, from transmitting the message based on a result of the determining, Determining, by the wireless device 14a, whether a condition for transmitting an unavailability message is fulfilled, Transmitting, by the wireless device 14a, the unavailability message to the node based on a result of the determining, and

[0090] Optionally, changing an operational mode of the wireless device 14a, preferably into an energy-saving or energy-harvesting mode.

[0091] In other words, the proposed solution introduces an energy status report procedure in wireless devices, preferably ambient loT devices. For reporting the R. 416157

[0092] - 13 - energy status to a reader or another node of the network, at least one of the following options may be used by the wireless device:

[0093] The energy status report or energy information may be transmitted, by the wireless device

[0094] - periodically, specifically based on a pre-configuration or a configuration received from a reader or another network node, e.g., an intermediate device such as relay or any other UE,

[0095] - upon reception of a trigger message from the reader or another network node, e.g., a relay or a UE,

[0096] - the energy status in a device meets a certain requirement for e.g., energy status is below a pre-defined or configured threshold,

[0097] - in case a remaining energy level of the device is not sufficient to transmit a (specific) block of data,

[0098] - when instructed by higher layers or a core network node, e.g., depending on a use case.

[0099] The energy status report or energy information may be transmitted from the wireless device to the reader or another network node, e.g., a relay or a UE, using one of the following formats:

[0100] - An independent message type which is sent by the wireless device o after a random access procedure in case the device wins the random access contention, or o within the random access procedure, e.g., after transmission of a random identifier which is transmitted by the device to the reader or another network, or o using dedicated transmission resources such as one or several scheduled time slot(s), specifically allocated to the device for the energy status report, either as part of or after the random access procedure.

[0101] - A message transmitted after transmission of device ID from the wireless device to the reader or relay or network or any UE.

[0102] - A message transmitted in response to receiving a paging message or after a paging occasion.

[0103] - A message transmitted after data or payload transmission, preferably of messages contained in a buffer of the device. R. 416157

[0104] - 14 -

[0105] - As a defined number of n bits of a random identifier transmitted by the device during random access procedure, e.g., n least or most significant bits of the identifier.

[0106] - As a sequence of n bits or a short message or a short notification, e.g., a notification to notify the reader or another network node that the transmission of an upcoming data block or of requested data or of buffer messages is not possible due to the energy status of the device.

[0107] The energy status report or the energy information can be represented by at least one of the following options or types of reports / information:

[0108] - A number of possible data blocks, e.g., a number of messages which can be transmitted by the device using the remaining energy, or

[0109] - A size of data which is possible to transmit using the remaining energy, or

[0110] - A number of contention attempts for channel access / participation, or

[0111] - A number of failures to bear, or

[0112] - A binary status report about a possibility of transmission of requested data blocks, or

[0113] - A bit sequence of N bits indicating a level of a remaining energy in the device, e.g., low, medium or high, preferably based on a predefined definition of each level of energy, or

[0114] - A single bit for indicating a low energy level in the device or for indicating that the next transmission is impossible.

[0115] Besides, further information may be included in the energy status report or the energy information, e.g., one bit to indicate that the device is capable of energy harvesting to increase its energy level, and / or multiple bits to additionally indicate a type of energy harvesting.

[0116] Preferably, in case the energy status report does not coincide with remedies for keeping the wireless device alive, an “out-of-service” information or report or indication may be provided, particularly as the last message before getting off. To this end, a standardized bit sequence may be used.

Claims

R. 416157- 15 -Claims1 . A method (100) for providing an energy information of a wireless device (14a, 14b, 14c; 14), preferably an ambient Internet of Things (loT) device (14a, 14b, 14c; 14), in a communication network (10), the method (100) comprising:Determining (120), by the wireless device (14a, 14b, 14c; 14), whether a condition for transmitting a message comprising an energy information of the wireless device (14a, 14b, 14c; 14) is fulfilled; and Transmitting (130), by the wireless device (14a, 14b, 14c; 14), the message based on a result of the determining (120) to a node (12) of the communication network (10).

2. The method (100) according to claim 1 , wherein the condition represents a relation between an energy level of the wireless device (14a, 14b, 14c; 14) and a requirement on the energy level of the wireless device (14a, 14b, 14c; 14).

3. The method (100) according to claim 2, wherein the requirement is based on a minimum energy level necessary for a transmission of the wireless device (14a, 14b, 14c; 14).

4. The method (100) according to one of the preceding claims, wherein the message is transmitted periodically by the wireless device (14a, 14b, 14c; 14), and a periodicity of the transmission is pre-configured or configured by the node (12) or a further node (16) of the communication network (10).

5. The method (100) according to one of the preceding claims, further comprising:Receiving (130), by the wireless device (14a, 14b, 14c; 14), a trigger message from the node (12) or a / the further node (16) of the communication network (10), wherein the step of determining (120) is carried out in response to receiving (130) the trigger message.R. 416157- 16 -6. The method (100) according to one of the preceding claims, wherein the step of determining (120) is carried out prior and / or during and / or after a random access procedure of the wireless device (14a, 14b, 14c; 14), and / or in response to monitoring, by the wireless device (14a, 14b, 14c; 14), a paging occasion and / or receiving, by the wireless device (14a, 14b, 14c; 14), a paging message; and / or after transmission of payload data by the wireless device (14a, 14b, 14c; 14).

7. The method (100) according to one of the preceding claims, wherein the message is configured as an energy reporting message specifically for reporting the energy information, and / or is a message of a random access procedure of the wireless device (14a, 14b, 14c; 14), particularly, of a first message and / or a third message of the random access procedure, and / or is a notification message for notifying the node (12) that the wireless device (14a, 14b, 14c; 14) is refraining from at least one future, specifically scheduled, transmission.

8. The method (100) according to claim 7, wherein the first message of the random access procedure comprises a random value and a defined number of bits representing the energy information.

9. The method (100) according to one of the preceding claims, wherein the energy information comprises at least one bit, preferably a bit sequence, representing a number and / or a size of data blocks and / or messages which may be transmitted by the wireless device (14a, 14b, 14c; 14) based on an / the energy level of the wireless device (14a, 14b, 14c; 14), and / or a number of contention attempts and / or a number of failed attempts of the wireless device (14a, 14b, 14c; 14) for accessing a transmission medium of the communication network (10) by initiating a / the random access procedure, and / orR. 416157- 17 - whether (requested) payload data may be transmitted or not, and / or a I the energy level of the wireless device (14a, 14b, 14c; 14).

10. The method (100) according to one of the preceding claims, wherein the energy information further represents a capability of the wireless device (14a, 14b, 14c; 14) for energy harvesting, and, optionally, which type(s) of energy harvesting the wireless device (14a, 14b, 14c; 14) is capable of.11 . The method (100) according to one of the preceding claims, further comprising:Refraining, by the wireless device (14a, 14b, 14c; 14), from transmitting the message based on a result of the determining (120), Determining, by the wireless device (14a, 14b, 14c; 14), whether a condition for transmitting an unavailability message is fulfilled, Transmitting, by the wireless device (14a, 14b, 14c; 14), the unavailability message to the node (12) based on a result of the determining, and Optionally, changing an operational mode of the wireless device (14a, 14b, 14c; 14), preferably into an energy-saving or energy-harvesting mode.

12. A wireless device of a communication network configured to execute the method (100) according to one of claims 1 to 11 .

13. A computer program comprising machine-readable instructions to cause the wireless device according to claim 12 to execute the method (100) according to one of claims 1 to 11 .

14. A non-transitory computer readable medium having stored thereon the computer program according to claim 13.

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