Method and apparatus for reducing signaling overhead for triggering uplink transmissions on an ambient IoT device

Abstract

The present disclosure relates to methods and apparatus for reducing signaling overhead for initiating uplink transmissions at a user equipment (UE) (20) including a wireless device (25) having an energy harvesting unit (254) that stores electrical energy in an energy storage unit (255) of the wireless device.

Description

Technical area

[0001] The present disclosure relates to wireless communication systems and, more particularly, to methods and apparatus for reducing signaling overhead for initiating uplink transmissions at an ambient IoT device. background

[0002] The Internet of Things (IoT) enables various devices to connect to the internet to send data, receive instructions, or both. Tens of billions of IoT devices are already deployed, and the global number of IoT devices is expected to grow rapidly. Thus, massive connectivity is required. However, powering these billions of IoT devices presents a critical challenge, and deploying power cables or regularly replacing / recharging batteries is not a practical solution.

[0003] 3GPP (Third Generation Partnership Project) is currently investigating new IoT technologies to open up new markets within 3GPP systems. These technologies can provide orders of magnitude higher connection counts and / or device density than existing 3GPP IoT technologies, and can provide orders of magnitude lower complexity and power consumption than existing 3GPP technologies, such as narrow-band IoT (NB-IoT) and long-term evolution-machine-type communications (LTE-MTC). Specifically, 3GPP currently defines ambient (A-loT) technologies (see, for example, technical report TR 38.848 V18.0).0) aiming to enable very low-power IoT devices, which could be either battery-less devices without energy storage capability (performing backscatter transmission) or devices with an energy storage that does not need to be manually replaced or recharged (performing wireless ambient energy harvesting (EH) from one or more energy sources).

[0004] By "very low-power" or "A-IoT" devices, the authors mean devices with a peak power consumption of less than 1 mW, or even less than 100 µW, or less than 10 µW. For example, Ambient IoT currently aims to enable A-IoT devices that have the following characteristics: - about 1 µW peak power consumption with energy storage, with neither DL (downlink) nor UL (uplink) amplification in the device (the UL transmission of the device is backscattered on an externally provided carrier wave), - below a few hundred µW peak power consumption with energy storage, with DL and / or UL amplification in the device (the UL transmission of the device can be generated internally by the device or backscattered on an externally provided carrier wave).

[0005] In some cases, such A-IoT devices can only initiate an uplink transmission when triggered by the radio access network (RAN). However, the signaling load on the RAN for triggering uplink transmissions by A-IoT devices increases dramatically as the number of deployed A-IoT devices increases. Brief description

[0006] The present disclosure aims to improve the situation. In particular, the present disclosure aims to address at least some of the limitations of the prior art discussed above. In particular, the present disclosure aims to propose a solution that makes it possible to reduce the signaling overhead with respect to wireless devices, such as A-IoT devices.

[0007] To this end, it is proposed that the RAN transmit a trigger signal for an uplink transmission to a wireless device, indicating that the wireless device can initiate an uplink transmission, and that the trigger signal include information regarding the properties of the triggered uplink transmission. Thus, in addition to indicating that the wireless device can initiate an uplink transmission, the trigger signal for an uplink transmission contains other information that does not need to be transmitted in a separate signaling message, thereby reducing the signaling overhead.

[0008] According to a first aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, wherein the method is implemented by a wireless device of the wireless communication system, wherein the wireless device comprises an energy harvesting unit configured to convert ambient energy into electrical energy that is stored in an energy storage unit of the wireless device, wherein the wireless device further comprises a communication unit configured to exchange data with a radio access network (RAN) of the wireless communication system, the method comprising: - receiving a trigger signal for an uplink transmission from the RAN, wherein the trigger signal for an uplink transmission contains information regarding at least one property of the triggered uplink transmission, - transmitting uplink data to the RAN, wherein the transmission of uplink data is controlled based on the information regarding at least one property of the triggered uplink transmission.

[0009] In some embodiments, the method according to the first aspect may further comprise one or more of the following optional features, which are contemplated either alone or in a technically possible combination.

[0010] In some embodiments of the method according to the first aspect, the information regarding at least one property of the triggered uplink transmission includes an indication of whether the trigger signal for an uplink transmission triggers repeated uplink transmissions.

[0011] In some embodiments of the method according to the first aspect, the information regarding at least one property of the triggered uplink transmission includes an indication of whether the triggered uplink transmission is a periodic uplink transmission.

[0012] In some embodiments of the method according to the first aspect, if the triggered uplink transmission is a periodic uplink transmission, the information regarding at least one property of the triggered uplink transmission includes an indication of a periodicity of the triggered uplink transmission.

[0013] In some embodiments, the method according to the first aspect comprises interrupting repeated uplink transmissions triggered by the uplink transmission trigger signal in response to receiving an uplink transmission interrupt signal from the RAN.

[0014] In some embodiments of the method according to the first aspect, the interrupt signal for an uplink transmission is received via L1 signaling and / or L2 signaling.

[0015] In some embodiments of the method according to the first aspect, the interrupt signal for an uplink transmission is received in a medium access control (MAC) control element (CE) or in downlink control information (DCI).

[0016] In some embodiments of the method according to the first aspect, the trigger signal for an uplink transmission is a wake-up signal that transitions the wireless device from a sleep mode to an active mode.

[0017] In some embodiments of the method according to the first aspect, the energy harvesting unit is a radio unit configured to convert a received radio frequency signal into electrical energy.

[0018] According to a second aspect, the present disclosure relates to a wireless device comprising at least one memory and at least one processor configured to perform a method according to any one of the embodiments of the first aspect.

[0019] According to a third aspect, the present disclosure relates to a user equipment (UE) comprising a wireless device according to any one of the embodiments of the present disclosure.

[0020] According to a fourth aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, wherein the method is implemented by a base station (BS) of a radio access network (RAN) of the wireless communication system, wherein the BS is configured to exchange data with a wireless device comprising an energy harvesting unit configured to convert ambient energy into electrical energy that is stored in an energy storage unit of the wireless device, wherein the method comprises transmitting, to the wireless device, a trigger signal for an uplink transmission, wherein the trigger signal for an uplink transmission contains information regarding at least one property of the triggered uplink transmission.

[0021] In some embodiments, the method according to the fourth aspect may further comprise one or more of the following optional features, contemplated either alone or in any technically possible combination.

[0022] In some embodiments of the method according to the fourth aspect, the information regarding at least one property of the triggered uplink transmission includes an indication of whether the trigger signal for an uplink transmission triggers repeated uplink transmissions.

[0023] In some embodiments of the method according to the fourth aspect, the information regarding at least one property of the triggered uplink transmission includes an indication of whether the triggered uplink transmission is a periodic uplink transmission.

[0024] In some embodiments of the method according to the fourth aspect, if the triggered uplink transmission is a periodic uplink transmission, the information regarding at least one property of the triggered uplink transmission includes an indication of a periodicity of the triggered uplink transmission.

[0025] In some embodiments, the method according to the fourth aspect includes transmitting an uplink transmission interrupt signal to the wireless device to interrupt repeated uplink transmissions.

[0026] In some embodiments of the method according to the fourth aspect, the interrupt signal for uplink transmission is transmitted via L1 signaling and / or L2 signaling.

[0027] In some embodiments of the method according to the fourth aspect, the interrupt signal for an uplink transmission is transmitted in a medium access control (MAC) control element (CE) or in downlink control information (DCI).

[0028] In some embodiments of the method according to the fourth aspect, the trigger signal for an uplink transmission is a wake-up signal that transitions the wireless device from a sleep mode to an active mode.

[0029] In some embodiments, the method according to the fourth aspect comprises beginning to transmit an energy harvesting signal to the wireless device prior to transmitting the signaling message to that wireless device.

[0030] According to a fifth aspect, the present disclosure relates to a base station (BS) comprising at least one memory and at least one processor configured to perform a method according to one of the embodiments of the fourth aspect.

[0031] According to a sixth aspect, the present disclosure relates to a wireless communication system comprising at least one base station according to one of the embodiments of the present disclosure and at least one user device according to one of the embodiments of the present disclosure.

[0032] According to a seventh aspect, the present disclosure relates to a computer program product comprising instructions that, when executed by at least one processor, configure the at least one processor to perform a method for exchanging data according to any one of the embodiments of the present disclosure. The computer program product may use any programming language and may be in the form of source code, object code, or any form between source code and object code, such as in a partially compiled form, or in any other desired form.

[0033] According to an eighth aspect, the present disclosure relates to a (non-transitory) computer-readable storage medium comprising instructions that, when executed by at least one processor, configure the at least one processor to perform a method for transmitting control messages according to any one of the embodiments of the present disclosure. Short description of the drawings

[0034] The invention will be better understood upon reading the following description, given as an example and in no way limiting, with reference to the figures, which show: - Fig. 1: schematic representations of various possible topologies of a wireless communication system, - Fig. 2: a schematic representation of an example of a wireless device, - Fig. 3: a schematic representation of an example of a BS, - Fig. 4 and Fig. 5: Flowcharts illustrating examples of methods for exchanging data implemented by a wireless device of a UE and a BS, respectively.

[0035] In these figures, reference numerals that are identical from one figure to another indicate identical or similar elements. For clarity, the elements shown are not to scale unless expressly stated otherwise. Detailed description

[0036] The detailed description below with reference to the figures is intended to be a description of various configurations and is not intended to represent the only configurations in which the presently described concepts may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. For example, while this disclosure may use 3GPP terminology, e.g., from 5G NR, to explain embodiments herein, this should not be seen as limiting the scope of the present disclosure.

[0037] In general, all terms used herein should be interpreted according to their usual meaning in the relevant technical field, unless another meaning is clearly indicated and / or clear from the context in which it is used. All references to an element, facility, component, means, step, etc. should be openly construed as referring to at least one instance of the element, facility, component, means, step, etc., unless expressly stated otherwise.Likewise, the order of steps of any methods disclosed herein, particularly in the figures, is provided for illustrative purposes only and does not imply any limitation on the present disclosure, which may be applied with the same steps performed in a different order and / or with all or part of the steps performed in parallel or together, unless a step is expressly described as following or preceding a step and / or where it is implicit that a step must follow or precede another step. Likewise, steps depicted in a figure that are surrounded by a dashed line are to be considered optional for the embodiment depicted in that figure.Any feature of any embodiment disclosed herein may be applied to any other embodiment whenever appropriate. Likewise, any advantage of any embodiment may be applied to any other embodiment, and vice versa. Other objects, features, and advantages of the included embodiments will become apparent from the following description.

[0038] Fig. Figure 1 schematically illustrates an example of a wireless communication system, which may be, for example, a 5G NR wireless communication system. In particular, Fig. 1 depicts a RAN of the wireless communication system used to exchange data with UEs 20 via radio signals. The RAN can, for example, send data to the UEs 20 (DL - downlink), such as data received from a core network (CN - core network, not shown in the figures). The RAN can also receive data from the UEs 20 (UL - uplink), and this data can be forwarded to the CN.

[0039] In the Fig. In the example illustrated in Figure 1, the RAN includes a base station (BS) 30. Of course, the RAN may include more than one BS 30 to expand the coverage area of the wireless communication system. Each of these BSs may be referred to as an NB, eNodeB (or eNB), gNodeB (or gNB in the case of a 5G NR wireless communication system), an access point, or the like, depending on the wireless communication standard(s) implemented.

[0040] In the Fig. In the example illustrated in Figure 1, only one UE 20 is shown, which includes a wireless device 25 that provides the UE 20 with wireless connectivity to the RAN of the wireless communication system. Part a) of Fig. Figure 1 schematically illustrates an example in which the UE 20 exchanges data (payload and control data) directly with a BS 30 of the RAN (referred to as Topology 1 in TR 38.848 V18.0.0). Part b) of Fig. Figure 1 schematically illustrates an example in which the UE 20 exchanges data (payload and control data) indirectly with a BS 30 of the RAN via one or more intermediate nodes 31 (referred to as Topology 2 in TR 38.848 V18.0.0). Each intermediate node 31 can be, for example, a relay, an IAB (integrated access and backhaul) node, another UE 20, a repeater, a reconfigurable intelligent surface (RIS), etc.

[0041] Fig. 2 schematically illustrates an example of a wireless device 25 suitable for implementing any method discussed in the present disclosure and performed on a UE 20. Essentially, the wireless device 25 corresponds to a device that provides wireless connectivity to the RAN of the wireless communication system and that can be used to exchange data with the RAN. The wireless device 25 is, for example, an A-IoT device, i.e., a wireless device that has a peak power consumption of less than 1 mW, or even less than 100 µW, or even less than 10 µW.

[0042] Such a wireless device 25 may be incorporated in a UE 20 as shown by Fig. 2. The UE 20 may be, for example, a mobile phone, a wireless modem, a wireless communication device, a handheld device, a laptop computer, or the like. In preferred examples, the UE 20 may also be an Internet of Things (IoT) device, such as a wireless camera, a smart sensor, a smart meter, smart glasses, a (manned or unmanned) vehicle, a Global Positioning System device, etc., or any other device capable of executing applications that require exchanging data with remote receivers via the wireless device 25.

[0043] As through Fig. 2, the wireless device 25 includes one or more processors 250 and one or more memories 251. The one or more processors 250 may include, for example, a central processing unit (CPU), a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc. The one or more memories 251 may include any type of computer-readable volatile and non-volatile memory (magnetic hard drive, solid state memory, optical disk, electronic memory, etc.).The one or more memories 251 may store a computer program product 252 in the form of a set of program-encoded instructions to be executed by the one or more processors 250 to implement all or part of the steps of a method for exchanging data performed on the side of a UE according to any of the embodiments disclosed herein.

[0044] As through Fig. As illustrated in Figure 2, the wireless device 25 also includes a (wireless) communication unit 253 configured to exchange data (directly or indirectly) with BSs 30 of the RAN using radio signals. The communication unit 253 may implement one or more wireless communication protocols and may, for example, be a 3G, 4G, 5G, NR, WiFi, WiMax, etc., transceiver or the like. In preferred embodiments, the (wireless) communication unit 253 includes a 5G NR wireless communication unit.

[0045] As discussed above, in some examples, communication unit 253 may include neither DL (downlink) nor UL (uplink) amplification capability (the UL transmission is backscattered on an externally provided carrier wave). In other examples, communication unit 253 may include DL and / or UL amplification (the UL transmission may be generated internally by the wireless device or backscattered on an externally provided carrier wave).

[0046] As through Fig. 2, the wireless device 25 also includes an energy harvesting unit 254 and a wireless device energy storage unit 255.

[0047] The energy storage unit 255 may be any type of electrical energy accumulator and may include, for example, one or more capacitors, one or more batteries, etc. The energy storage unit 255 is used to provide electrical energy to the other features of the wireless device 25 that require electrical energy, such as the one or more processors 250, the one or more memories 251, and in some cases, the (wireless) communication unit 253.

[0048] The energy harvesting unit 254 is configured to convert ambient energy into electrical energy, which is stored in the energy storage unit 255. By "ambient energy," the authors mean energy from energy sources external to the wireless device 25 that is received at the wireless device 25 without any wires between the energy sources and the wireless device 25. Thus, the energy harvesting unit 254 is configured such that the wireless device 25 can operate autonomously without the need to manually replace or recharge the energy storage unit 255. The energy harvesting unit 254 can, for example, collect energy from various energy sources, including solar, heat, motion or vibration, radio frequency (RF), etc.

[0049] In preferred embodiments, the energy harvesting unit 254 comprises at least one radio unit configured to convert RF signals into electrical energy, which is stored in the energy storage unit 255. These RF signals may, for example, be external RF signals, i.e., RF signals that do not originate from within the wireless communication system itself, but from RF sources located outside the wireless communication system. For example, external RF signals may originate from external 3G, 4G, 5G, NR, WiFi, WiMax, Bluetooth, DAB, etc. devices located in the vicinity of the wireless device 25.Alternatively, or in combination, the RF signals may originate from within the wireless communication system, for example, from BSs 30 of the RAN that may transmit an energy harvesting (RF) signal to wireless (A-IoT) devices 25 within their coverage area, and / or from devices separate from the BSs 30 but deployed to enable energy harvesting on the wireless (A-IoT) devices 25 of the wireless communication system. In some examples, if RF signals are used to feed electrical energy to the energy storage unit 255, the energy harvesting unit 254 may be included in the (wireless) communication unit 253.

[0050] Fig. 3 schematically illustrates an example of a BS 30 suitable for implementing a method discussed in the present disclosure as well as performed by the RAN.

[0051] As through Fig. 3, the OS 30 includes one or more processors 300 and one or more memories 301. The one or more processors 300 may include, for example, a central processing unit (CPU), a digital signal processor (DSP), a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), etc. The one or more memories 301 may include any type of computer-readable volatile and non-volatile memory (magnetic hard disk, solid state memory, optical disk, electronic memory, etc.).The one or more memories 301 may store a computer program product 302 in the form of a set of program-encoded instructions to be executed by the one or more processors 300 to implement all or part of the steps of a method for exchanging data performed at the RAN side according to any of the embodiments disclosed herein.

[0052] As through Fig. 3, the BS 30 also includes a wireless communication unit 303 configured to exchange data with UEs 20 using radio signals, and in particular with (wireless) communication units 253 of wireless devices 25 included in these UEs 20. The wireless communication unit 303 may, for example, be a 3G, 4G, 5G, NR, WiFi, WiMax, etc. transceiver or the like. In preferred embodiments, the wireless communication unit 303 of the BS 30 includes a 5G NR transceiver. In some examples, the wireless communication unit 303 may also transmit carrier waves to the wireless devices 25, performing uplink transmissions with backscatter.

[0053] As through Fig. As illustrated in Figure 3, in some examples, the BS 30 may also include a network communication unit 304 configured to exchange data with other base stations of the RAN and / or with the CN. The network communication unit 305 may support one or more suitable communication protocols, which may be wired (including fiber optic) and / or wireless.

[0054] As through Fig. 3, in some examples, the BS 30 may also include an energy harvesting signal generator 305 that generates energy harvesting (RF) signals that enable wireless devices 25 in its coverage area to feed electrical energy into their energy storage units 255 via their energy harvesting units 254. The energy harvesting (RF) signals may take any suitable form that enables the energy harvesting units 254 to store electrical energy in the energy storage units 255 of the wireless devices 25. The choice of a specific energy harvesting (RF) signal format is a specific and non-limiting embodiment of the present disclosure. As noted above, such energy harvesting (RF) signals may, where appropriate, alternatively or in combination, be generated by other devices separate from the RAN's BSs 30.

[0055] As discussed above, the present disclosure aims to reduce the signaling load on the RAN for handling wireless devices 25, such as A-IoT devices.

[0056] To this end, it is proposed that the RAN transmit an uplink transmission trigger signal to a wireless device 25, indicating that the wireless device 25 can initiate an uplink transmission, and include information regarding properties of the triggered uplink transmission in the uplink transmission trigger signal. Thus, in addition to indicating that the wireless device 25 can initiate an uplink transmission, the uplink transmission trigger signal contains other information that does not need to be transmitted in a separate signaling message, thereby reducing the signaling overhead.

[0057] The authors now present non-limiting examples of embodiments of the present disclosure.

[0058] Fig. 4 illustrates a diagram showing steps of an exemplary embodiment of a method 40 for exchanging data implemented by a wireless device 25 of a UE 20. Fig. 5 illustrates a diagram showing respective steps of an exemplary embodiment of a method 50 for exchanging data implemented by a BS 30 of the RAN.

[0059] As through Fig. 4, the method 40 for exchanging data includes a step S40 of receiving a trigger signal for an uplink transmission from the RAN.

[0060] The purpose of the uplink transmission trigger signal is to indicate to the wireless device 25 that it may initiate an uplink data transmission.

[0061] For example, upon receiving an uplink transmission trigger signal from the RAN, the wireless device 25 may decide to transmit uplink data during an upcoming uplink transmission opportunity. For example, an uplink transmission opportunity corresponds to uplink resources that the wireless device 25 may use. For example, such uplink resources may be contention-based uplink resources, such as random access channel (RACH) uplink resources or configured grant (CG) uplink resources, etc. In other examples, such uplink resources may be specifically assigned to the wireless device 25, such as scheduling request (SR) resources.

[0062] To reduce its electrical power consumption, the wireless device 25 may be placed in a sleep mode. In such a case, the wireless device 25 must transition to an active mode to be able to perform the uplink data transmission. Such a transition may be triggered by the RAN sending a wake-up signal to the wireless device 25. In such a case, the trigger signal for an uplink transmission may correspond to the wake-up signal that transitions the wireless device 25 from a sleep mode to an active mode, or it may be transmitted by the RAN after the RAN transmits a wake-up signal to the wireless device 25. Using the same signal for the wake-up signal and the trigger signal for an uplink transmission further reduces the signaling overhead for the RAN compared to using separate signals.

[0063] As discussed above, the uplink transmission trigger signal contains information regarding at least one characteristic of the triggered uplink transmission. Thus, the uplink transmission trigger signal also carries information used by wireless device 25 to control the transmission of uplink data.

[0064] For example, the information contained in the trigger signal for an uplink transmission may include an indication of a traffic class of the uplink data to be included in the triggered uplink transmission. For example, the traffic class may correspond to: a priority level of the uplink data to be transmitted (e.g., enabling wireless device 25 to only transmit uplink data whose priority level matches the specified priority level), a latency requirement (quality of service (QoS)) of the uplink data to be transmitted (e.g., enabling wireless device 25 to only transmit uplink data whose latency requirement matches the specified latency requirement), etc.

[0065] Alternatively, or in combination, the information included in the uplink transmission trigger signal may include an indication of the uplink transmission opportunities that wireless device 25 may use to transmit uplink data. It is noted that in other examples, the uplink transmission opportunities may be previously known to wireless device 25 (e.g., previously received from the RAN, for example, in system information broadcast by the RAN or in a signaling message specifically addressed to wireless device 25 or to a group of wireless devices including wireless device 25), so they need not be specified in the uplink transmission trigger signal.

[0066] Alternatively, or in combination, the information included in the uplink transmission trigger signal may include an indication of whether the uplink transmission trigger signal triggers repeated uplink transmissions. In other words, the information may indicate whether the uplink transmission trigger signal triggers a plurality of uplink transmissions or a single uplink transmission. If the information indicates that the uplink transmission trigger signal triggers repeated uplink transmissions, this means that the wireless device 25 can initiate subsequent repeated uplink transmissions without first having to receive another uplink transmission trigger signal from the RAN.This further reduces the signaling overhead for the RAN since the RAN only needs to transmit a single uplink transmission trigger signal to the wireless device 25 to trigger a plurality of repeated uplink data transmissions.

[0067] For example, the indication as to whether the uplink transmission trigger signal triggers repeated uplink transmissions may consist of a single bit with, for example, a value of '1' indicating that the uplink transmission trigger signal triggers repeated uplink transmissions and a value of '0' indicating that the uplink transmission trigger signal does not trigger repeated uplink transmissions (e.g., it triggers a single uplink transmission).

[0068] Of course, other formats for such an indication may be contemplated, and the selection of a specific format is a specific, but non-limiting, embodiment of the present disclosure. Likewise, in some cases, the information may also include additional information related to, for example, the triggered repeated uplink transmissions. For example, when repeated uplink transmissions are triggered, the uplink transmission trigger signal may, in some examples, include an indication of, for example, a maximum number of triggered uplink transmissions (limiting the number of uplink transmissions that wireless device 25 can initiate without receiving another uplink transmission trigger signal), a maximum duration during which wireless device 25 can initiate uplink transmissions without receiving another uplink transmission trigger signal, etc.

[0069] In some examples, the triggered repeated uplink transmissions may be periodic. For example, the periodicity of such uplink transmissions may be preconfigured at the wireless device 25, for example, predefined (e.g., specified by a standard) or previously received from the RAN (e.g., in system information broadcast by the RAN). In other examples, the periodicity of the triggered uplink transmissions may be specified directly in the trigger signal for an uplink transmission.

[0070] In the following, the authors consider, in a non-limiting manner, that the uplink transmission trigger signal includes at least an indication of whether the uplink transmission trigger signal triggers repeated uplink transmissions.

[0071] As through Fig. 4, the wireless device 25 therefore includes a step S41 of evaluating the information contained in the uplink transmission trigger signal (received in step S40) to determine whether repeated (e.g., periodic) uplink transmissions are triggered by the RAN.

[0072] In response to determining that the uplink transmission trigger signal does not trigger repeated uplink transmissions (reference symbol S41a in Fig. 4), the method 40 for exchanging data comprises a single step S42 of transmitting uplink data. However, the method 40 for exchanging data comprises, in response to determining that the uplink transmission trigger signal triggers repeated uplink transmissions (reference symbol S41b in Fig. 4) a step S43 of transmitting uplink data, which is repeated several times (e.g. periodically).

[0073] In the non-limiting example of Fig. 4, the method 40 for exchanging data includes a step S44 of evaluating whether the repeated uplink transmissions should be interrupted. If the wireless device 25 determines that the repeated uplink transmissions need to be interrupted (reference symbol S44a in Fig. 4), then the wireless device 25 interrupts the repeated uplink transmissions. However, if the wireless device 25 determines that the repeated uplink transmissions do not need to be interrupted (reference symbol S44b in Fig. 4), then the wireless device 25 may repeat step S43 of transmitting uplink data to the RAN.

[0074] For example, as discussed above, the uplink transmission trigger signal may include information that places a time limit on repeated uplink transmissions (e.g., a maximum number or maximum duration of triggered uplink transmissions), and the wireless device 25 may evaluate whether the specified limit has been reached.

[0075] Alternatively, or in combination therewith, in some examples, the RAN may also interrupt the triggered repeated uplink transmissions by sending an uplink transmission interrupt signal to the wireless device 25. Step S44 may therefore include evaluating whether an uplink transmission interrupt signal has been received from the RAN. If no uplink transmission interrupt signal has been received (reference symbol S44b in Fig. 4), then the wireless device 25 may repeat step S43 of transmitting uplink data to the RAN. On the other hand, if the wireless device 25 has received an uplink transmission interrupt signal (reference symbol S44a in Fig. 4), then the wireless device 25 interrupts the repeated uplink transmissions. For example, the interrupt signal for an uplink transmission may be received from the RAN via L1 signaling and / or L2 signaling. For example, the interrupt signal for an uplink transmission may be transmitted by the RAN as a medium access control (MAC) control element (CE) or in downlink control information (DCI).

[0076] As discussed above, Fig. 5 is a diagram illustrating corresponding steps of an exemplary embodiment of a method 50 for exchanging data that may be implemented by a BS 30 when the wireless device 25 executes the method 40 for exchanging data that may be implemented by Fig. 4 is implemented.

[0077] As through Fig. 5, the method 50 for exchanging data includes a step S50 of transmitting, by the BS 30, a trigger signal for an uplink transmission (received by the wireless device 25 at step S40).

[0078] It is noted that any suitable format may be used for the uplink transmission trigger signal, and that the selection of a specific format for the uplink transmission trigger signal corresponds to a specific, but non-limiting, embodiment of the present disclosure. It is also noted that in some examples, the uplink transmission trigger signal may correspond to the wake-up signal transitioning the wireless device 25 from a sleep mode to an active mode, or it may be transmitted by the RAN after the RAN transmits a wake-up signal to the wireless device 25.

[0079] As discussed above, the uplink transmission trigger signal contains information regarding at least one property of the triggered uplink transmission, which may, for example, correspond to: an indication of a traffic class, an indication of uplink transmission opportunities, an indication of whether the uplink transmission trigger signal triggers repeated uplink transmissions, etc.

[0080] In the example of Fig. 5, it is assumed, in a non-limiting manner, that the uplink transmission trigger signal includes at least an indication of whether the uplink transmission trigger signal triggers repeated (e.g., periodic) uplink transmissions. Non-limiting examples of such an indication have already been provided above.

[0081] If the uplink transmission trigger signal transmitted by the BS 30 does not trigger repeated uplink transmissions (reference symbol S50a in Fig. 5), the method 50 for exchanging data comprises a single step S51 of receiving uplink data from the wireless device 25. In the example of Fig. 5, a subsequent uplink data transmission by the wireless device 25 must first be triggered by the BS 30. However, if the trigger signal for an uplink transmission triggers repeated uplink transmissions (reference symbol S50b in Fig. 5), the method 50 for exchanging data comprises a repeated step S52 of receiving uplink data, which is repeated several times (e.g., periodically).

[0082] In the non-limiting example of Fig. 5, it is assumed, in a non-limiting manner, that the BS 30 may interrupt the repeated uplink transmissions by transmitting an uplink transmission interrupt signal to the wireless device 25. Accordingly, the method 50 for exchanging data includes a step S53 of evaluating whether an uplink transmission interrupt signal needs to be transmitted to the wireless device 25.

[0083] As through Fig. 5, the method 50 includes exchanging data when the BS 30 determines that the repeated uplink transmissions need to be interrupted (reference sign S53a in Fig. 5), then a step S54 of transmitting an uplink interrupt signal to the wireless device 25. It is noted that any suitable format may be used for the uplink interrupt signal, and that the selection of a specific format for the uplink interrupt signal corresponds to a specific, but non-limiting, embodiment of the present disclosure. As discussed above, the uplink interrupt signal may be transmitted, for example, via L1 signaling and / or L2 signaling by the BS 30 (e.g., MAC-CE, DCI, etc.).

[0084] If, however, the BS 30 determines that the repeated uplink transmissions do not need to be interrupted (reference sign S53b in Fig. 5), then the BS 30 repeats step S52 of receiving uplink data from the wireless device 25.

[0085] For example, in examples where the BS 30 includes an energy harvesting signal generator 305, the BS 30 may begin transmitting an energy harvesting (RF) signal to the wireless device 25 before transmitting the trigger signal for an uplink transmission to the wireless device 25 (in Fig. 5 not shown).

[0086] It is emphasized that the present disclosure is not limited to the above exemplary embodiments. Variants of the above exemplary embodiments also fall within the scope of the present disclosure.

Claims

[1] A method (40) for exchanging data in a wireless communication system, the method being implemented by a wireless device (25) of the wireless communication system, the wireless device comprising an energy harvesting unit (254) configured to convert ambient energy into electrical energy that is stored in an energy storage unit (255) of the wireless device, the wireless device further comprising a communication unit (253) configured to exchange data with a radio access network (RAN) of the wireless communication system, the method comprising: - (S40) receiving a trigger signal for an uplink transmission from the RAN, wherein the trigger signal for an uplink transmission contains information regarding at least one property of the triggered uplink transmission, - (S42, S43) transmitting uplink data to the RAN, wherein the transmission of uplink data is controlled based on the information regarding at least one property of the triggered uplink transmission. [2] The method (40) of claim 1, wherein the information regarding at least one property of the triggered uplink transmission includes an indication of whether the uplink transmission trigger signal triggers repeated uplink transmissions. [3] The method (40) of claim 2, wherein the information regarding at least one property of the triggered uplink transmission includes an indication of whether the triggered transmission is a periodic uplink transmission. [4] The method (40) of claim 3, wherein, when the triggered uplink transmission is a periodic uplink transmission, the information regarding at least one property of the triggered uplink transmission includes an indication of a periodicity of the triggered uplink transmission. [5] The method (40) of any one of claims 2 to 4, comprising interrupting repeated uplink transmissions triggered by the uplink transmission trigger signal in response to receiving an uplink transmission interrupt signal from the RAN. [6] The method (40) of claim 5, wherein the interrupt signal for an uplink transmission is received via L1 signaling and / or L2 signaling. [7] The method (40) of claim 6, wherein the interrupt signal for an uplink transmission is received in a medium access control (MAC) control element (CE) or in downlink control information (DCI). [8] The method (40) of any preceding claim, wherein the uplink transmission trigger signal is a wake-up signal transitioning the wireless device from a sleep mode to an active mode. [9] A wireless device (25) comprising at least one memory and at least one processor configured to perform a method (40) according to any one of the preceding claims. [10] A user equipment (UE) (20) comprising a wireless device according to claim 9. [11] A method (50) for exchanging data in a wireless communication system, the method being implemented by a base station (BS) (30) of a radio access network (RAN) of the wireless communication system, the BS being configured to exchange data with a wireless device (25) comprising an energy harvesting unit (254) configured to convert ambient energy into electrical energy that is stored in an energy storage unit (255) of the wireless device, the method (S50) comprising transmitting, to the wireless device (25), a trigger signal for an uplink transmission, the trigger signal for an uplink transmission containing information regarding at least one property of the triggered uplink transmission. [12] The method (50) of claim 11, wherein the information regarding at least one property of the triggered uplink transmission includes an indication of whether the uplink transmission trigger signal triggers repeated uplink transmissions. [13] The method (50) of claim 12, wherein the information regarding at least one property of the triggered uplink transmission includes an indication of whether the triggered transmission is a periodic uplink transmission. [14] The method (50) of claim 13, wherein, when the triggered uplink transmission is a periodic uplink transmission, the information regarding at least one property of the triggered uplink transmission includes an indication of a periodicity of the triggered uplink transmission. [15] The method (50) of any one of claims 12 to 14, comprising (S54) transmitting an uplink transmission interrupt signal to the wireless device to interrupt repeated uplink transmissions. [16] The method (50) of claim 15, wherein the interrupt signal for an uplink transmission is transmitted via L1 signaling and / or L2 signaling. [17] The method (50) of claim 16, wherein the interrupt signal for an uplink transmission is transmitted in a medium access control (MAC) control element (CE) or in downlink control information (DCI). [18] The method (50) of any one of claims 11 to 17, wherein the trigger signal for an uplink transmission is a wake-up signal that transitions the wireless device from a sleep mode to an active mode. [19] Base station (BS - base station) (30), comprising at least one memory and at least one processor configured to carry out a method (50) according to one of claims 11 to 18. [20] A wireless communication system comprising at least one base station (30) according to claim 19 and at least one user device (20) according to claim 10. [21] A computer program product (252, 302) comprising instructions that, when executed by at least one processor, configure the at least one processor to perform a method (40) according to any one of claims 1 to 8 or a method (50) according to any one of claims 11 to 18. [22] A computer-readable storage medium comprising instructions that, when executed by at least one processor, configure the at least one processor to perform a method (40) according to any one of claims 1 to 8 or a method (50) according to any one of claims 11 to 18.

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